%0 Journal Article %~ PubMed %A Götz, Jürgen %A Matamales, Miriam %A Götz, Naeman N %A Ittner, Lars M %A Eckert, Anne %T Alzheimer's disease models and functional genomics-How many needles are there in the haystack? %B Frontiers in Physiology %D 2012 %C Switzerland %I Frontiers Research Foundation %V 3 %N %P 320 %@ 1664-042X %X %Z FOR Codes: 110904 %0 Journal Article %~ PubMed %A Scarf, Alana M %A Luus, Christopher %A Da Pozzo, Eleonora %A Selleri, Silvia %A Guarino, Chiara %A Martini, Claudia %A Ittner, Lars M %A Kassiou, Michael %T Evidence for Complex Binding Profiles and Species Differences at the Translocator Protein (TSPO) (18 kDa). %B Current Molecular Medicine %D 2012 %C Netherlands %I Bentham Science Publishers Ltd. %V 12 %N 4 %P 488-493 %@ 1875-5666 %X The translocator protein (TSPO) (18 kDa) is an emerging drug target for the treatment of numerous pathologies including cancer and neurodegenerative disease. However, our limited knowledge of TSPO binding site(s) has hindered the development of TSPO ligands with potential therapeutic effects. We have synthesized a series of pyrrolobenzoxazepines (1-10) to better characterize the interaction of ligands with the TSPO across species, and to determine their functional profiles. All ligands 1-10 displaced the binding of [3H]PK 11195 to the TSPO at nanomolar concentrations, with discrepancies in binding affinity between rat and human TSPO. Interestingly, non-linear regression analysis revealed that some ligands bound to the protein with a Hill slope not equal to 1.0, suggesting possible additional TSPO binding sites with allosteric effects. However, this trend was not conserved between rat and human. When tested for their effects on pregnenolone production in rat C6 glioma cells, nitric oxide release in murine microglia, and cell proliferation in human MCF-7 breast cancer cells, the pyrrolobenzoxazepines (40 ??M) displayed functional effects which did not correlate to the binding trend observed in competition assays. We propose that consideration of species differences and binding site cooperativity, plus optimization of currently accepted functional assays, will aid in the development of drugs targeting TSPO that can be used as therapeutics for human disease. %Z FOR Codes: 30401 %0 Journal Article %~ PubMed %A Ke, Yazi D %A Suchowerska, Alexandra K %A van der Hoven, Julia %A De Silva, Dineeka M %A Wu, Christopher W %A van Eersel, Janet %A Ittner, Arne %A Ittner, Lars M %T Lessons from tau-deficient mice. %B International Journal of Alzheimer's Disease %D 2012 %C United States %I Hindawi Publishing Corporation %V 2012 %N %P 873270 %@ 2090-0252 %X Both Alzheimer''s disease (AD) and frontotemporal dementia (FTD) are characterized by the deposition of hyperphosphorylated forms of the microtubule-associated protein tau in neurons and/or glia. This unifying pathology led to the umbrella term "tauopathies" for these conditions, also emphasizing the central role of tau in AD and FTD. Generation of transgenic mouse models expressing human tau in the brain has contributed to the understanding of the pathomechanistic role of tau in disease. To reveal the physiological functions of tau in vivo, several knockout mouse strains with deletion of the tau-encoding MAPT gene have been established over the past decade, using different gene targeting constructs. Surprisingly, when initially introduced tau knockout mice presented with no overt phenotype or malformations. The number of publications using tau knockout mice has recently markedly increased, and both behavioural changes and motor deficits have been identified in aged mice of certain strains. Moreover, tau knockout mice have been instrumental in identifying novel functions of tau, both in cultured neurons and in vivo. Importantly, tau knockout mice have significantly contributed to the understanding of the pathophysiological interplay between A?? and tau in AD. Here, we review the literature that involves tau knockout mice to summarize what we have learned so far from depleting tau in vivo. %Z FOR Codes: 110902 %0 Journal Article %~ PubMed %A Schonrock, Nicole %A Matamales, Miriam %A Ittner, Lars M %A Götz, Jürgen %T MicroRNA networks surrounding APP and amyloid-β metabolism-implications for Alzheimer's disease. %B Experimental Neurology %D 2012 %C United States %I Academic Press %V 235 %N 2 %P 447-454 %@ 1090-2430 %X MicroRNAs (miRNAs) are small non-coding RNA regulators of protein synthesis that function as "fine-tuning" tools of gene expression in development and tissue homeostasis. Their profiles are significantly altered in neurodegenerative diseases such as Alzheimer''s disease (AD) that is characterized by both amyloid-? (A?) and tau deposition in brain. A key challenge remains in determining how changes in miRNA profiles translate into biological function in a physiological and pathological context. The key lies in identifying specific target genes for deregulated miRNAs and understanding which pathogenic factors trigger their deregulation. Here we review the literature about the intricate network of miRNAs surrounding the regulation of the amyloid precursor protein (APP) from which A? is derived by proteolytic cleavage. Normal brain function is highly sensitive to any changes in APP metabolism and miRNAs function at several steps to ensure that the correct APP end product is produced and in the right form and abundance. Disruptions in this miRNA regulatory network may therefore alter A? production, which in turn can affect miRNA expression. %Z FOR Codes: 110902 %0 Journal Article %~ PubMed %A Rosenmann, Hanna %A Blum, David %A Kayed, Rakez %A Ittner, Lars M %T Tau protein: function and pathology. %B International Journal of Alzheimer's Disease %D 2012 %C United States %I Hindawi Publishing Corporation %V 2012 %N %P 707482 %@ 2090-0252 %X %Z FOR Codes: 110904 %0 Journal Article %~ PubMed %A Ke, Yazi %A Dramiga, Joe %A Sch??tz, Ulrich %A Kril, Jillian J %A Ittner, Lars M %A Schr??der, Hannsj??rg %A G??tz, J??rgen %T Tau-Mediated Nuclear Depletion and Cytoplasmic Accumulation of SFPQ in Alzheimer's and Pick's Disease. %B PLoS One %D 2012 %C United States %I Public Library of Science %V 7 %N 4 %P e35678 %@ 1932-6203 %X Tau dysfunction characterizes neurodegenerative diseases such as Alzheimer''s disease (AD) and frontotemporal lobar degeneration (FTLD). Here, we performed an unbiased SAGE (serial analysis of gene expression) of differentially expressed mRNAs in the amygdala of transgenic pR5 mice that express human tau carrying the P301L mutation previously identified in familial cases of FTLD. SAGE identified 29 deregulated transcripts including Sfpq that encodes a nuclear factor implicated in the splicing and regulation of gene expression. To assess the relevance for human disease we analyzed brains from AD, Pick''s disease (PiD, a form of FTLD), and control cases. Strikingly, in AD and PiD, both dementias with a tau pathology, affected brain areas showed a virtually complete nuclear depletion of SFPQ in both neurons and astrocytes, along with cytoplasmic accumulation. Accordingly, neurons harboring either AD tangles or Pick bodies were also depleted of SFPQ. Immunoblot analysis of human entorhinal cortex samples revealed reduced SFPQ levels with advanced Braak stages suggesting that the SFPQ pathology may progress together with the tau pathology in AD. To determine a causal role for tau, we stably expressed both wild-type and P301L human tau in human SH-SY5Y neuroblastoma cells, an established cell culture model of tau pathology. The cells were differentiated by two independent methods, mitomycin C-mediated cell cycle arrest or neuronal differentiation with retinoic acid. Confocal microscopy revealed that SFPQ was confined to nuclei in non-transfected wild-type cells, whereas in wild-type and P301L tau over-expressing cells, irrespective of the differentiation method, it formed aggregates in the cytoplasm, suggesting that pathogenic tau drives SFPQ pathology in post-mitotic cells. Our findings add SFPQ to a growing list of transcription factors with an altered nucleo-cytoplasmic distribution under neurodegenerative conditions. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Ittner, Arne %A Ittner, Lars M %T Tau-targeted treatment strategies in Alzheimer's disease. %B British Journal of Pharmacology %D 2012 %C United Kingdom %I John Wiley & Sons Ltd. %V 165 %N 5 %P 1246-1259 %@ 0007-1188 %X With populations ageing worldwide, the need for treating and preventing diseases associated with high age is pertinent. Alzheimer''s disease (AD) is reaching epidemic proportions, yet the currently available therapies are limited to a symptomatic relief, without halting the degenerative process that characterizes the AD brain. As in AD cholinergic neurons are lost at high numbers, the initial strategies were limited to the development of acetylcholinesterase inhibitors, and more recently the NMDA receptor antagonist memantine, in counteracting excitotoxicity. With the identification of the protein tau in intracellular neurofibrillary tangles and of the peptide amyloid-?? (A??) in extracellular amyloid plaques in the AD brain, and a better understanding of their role in disease, newer strategies are emerging, which aim at either preventing their formation and deposition or at accelerating their clearance. Interestingly, what is well established to combat viral diseases in peripheral organs - vaccination - seems to work for the brain as well. Accordingly, immunization strategies targeting A?? show efficacy in mice and to some degree also in humans. Even more surprising is the finding in mice that immunization strategies targeting tau, a protein that forms aggregates in nerve cells, ameliorates the tau-associated pathology. We are reviewing the literature and discuss what can be expected regarding the translation into clinical practice and how the findings can be extended to other neurodegenerative diseases with protein aggregation in brain. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Ittner, Lars M %A Götz, Jürgen %T Amyloid-β and tau - a toxic pas de deux in Alzheimer's disease. %B Nature reviews. Neuroscience %D 2011 %C United Kingdom %I Nature Publishing Group %V 12 %N 2 %P 65-72 %@ 1471-0048 %X Amyloid-?? and tau are the two hallmark proteins in Alzheimer''s disease. Although both amyloid-?? and tau have been extensively studied individually with regard to their separate modes of toxicity, more recently new light has been shed on their possible interactions and synergistic effects in Alzheimer''s disease. Here, we review novel findings that have shifted our understanding of the role of tau in the pathogenesis of Alzheimer''s disease towards being a crucial partner of amyloid-??. As we gain a deeper understanding of the different cellular functions of tau, the focus shifts from the axon, where tau has a principal role as a microtubule-associated protein, to the dendrite, where it mediates amyloid-?? toxicity. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Ittner, Arne %A Ke, Yazi D %A Eersel, Janet van %A Gladbach, Amadeus %A Götz, Jürgen %A Ittner, Lars M %T Brief update on different roles of tau in neurodegeneration. %B IUBMB Life %D 2011 %C United Kingdom %I Wiley-Blackwell Publishing Ltd. %V 63 %N 7 %P 495-502 %@ 1521-6551 %X Both Alzheimer''s disease (AD) and almost every second case of frontotemporal lobar degeneration (FTLD) are characterized by the deposition of hyperphosphorylated forms of the microtubule-associated protein tau in neurons and/or glia. This unifying pathology led to coining the umbrella term "tauopathies" for these conditions. While the deposition of tau ultimately results in the formation of typical histopathological lesions, such as the neurofibrillary tangles (NFTs) in AD, it is now well accepted that tau interferes with normal functions in neurons already before its deposition. Together with the identification of pathogenic mutations in the tau-encoding gene MAPT in FTLD and evidence from a rising number of in vivo animal models a central role of tau in neurodegeneration has emerged. Here, we review the role of pathological tau in axonal transport, mitochondrial respiration, and in mediating amyloid-?? toxicity in AD. Furthermore, we review recent findings regarding the spreading of tau pathology throughout the brain as disease progresses. ?? 2011 IUBMB IUBMB Life, 63(7): 495-502, 2011. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A van Eersel, Janet %A Ke, Yazi D %A Gladbach, Amadeus %A Bi, Mian %A Götz, Jürgen %A Kril, Jillian J %A Ittner, Lars M %T Cytoplasmic Accumulation and Aggregation of TDP-43 upon Proteasome Inhibition in Cultured Neurons. %B PloS One %D 2011 %C United States %I Public Library of Science %V 6 %N 7 %P e22850 %@ 1932-6203 %X Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are characterized by intraneuronal deposition of the nuclear TAR DNA-binding protein 43 (TDP-43) caused by unknown mechanisms. Here, we studied TDP-43 in primary neurons under different stress conditions and found that only proteasome inhibition by MG-132 or lactacystin could induce significant cytoplasmic accumulation of TDP-43, a histopathological hallmark in disease. This cytoplasmic accumulation was accompanied by phosphorylation, ubiquitination and aggregation of TDP-43, recapitulating major features of disease. Proteasome inhibition produced similar effects in both hippocampal and cortical neurons, as well as in immortalized motor neurons. To determine the contribution of TDP-43 to cell death, we reduced TDP-43 expression using small interfering RNA (siRNA), and found that reduced levels of TDP-43 dose-dependently rendered neurons more vulnerable to MG-132. Taken together, our data suggests a role for the proteasome in subcellular localization of TDP-43, and possibly in disease. %Z FOR Codes: 110902 %0 Journal Article %~ PubMed %A Liu, Xin %A Dobbie, Michael %A Tunningley, Rob %A Whittle, Belinda %A Zhang, Yafei %A Ittner, Lars M %A Götz, Jürgen %T ENU Mutagenesis Screen to Establish Motor Phenotypes in Wild-Type Mice and Modifiers of a Pre-Existing Motor Phenotype in Tau Mutant Mice. %B Journal of Biomedicine & Biotechnology %D 2011 %C United States %I Hindawi Publishing Corporation %V 2011 %N %P 130947 %@ 1110-7251 %X Modifier screening is a powerful genetic tool. While not widely used in the vertebrate system, we applied these tools to transgenic mouse strains that recapitulate key aspects of Alzheimer''s disease (AD), such as tau-expressing mice. These are characterized by a robust pathology including both motor and memory impairment. The phenotype can be modulated by ENU mutagenesis, which results in novel mutant mouse strains and allows identifying the underlying gene/mutation. Here we discuss this strategy in detail. We firstly obtained pedigrees that modify the tau-related motor phenotype, with mapping ongoing. We further obtained transgene-independent motor pedigrees: (i) hyperactive, circling ENU 37 mice with a causal mutation in the Tbx1 gene-the complete knock-out of Tbx1 models DiGeorge Syndrome; (ii) ENU12/301 mice that show sudden jerky movements and tremor constantly; they have a causal mutation in the Kcnq1 gene, modelling aspects of the Romano-Ward and Jervell and Lange-Nielsen syndromes; and (iii) ENU16/069 mice with tremor and hypermetric gait that have a causal mutation in the Mpz (Myelin Protein Zero) gene, modelling Charcot-Marie-Tooth disease type 1 (CMT1B). Together, we provide evidence for a real potential of an ENU mutagenesis to dissect motor functions in wild-type and tau mutant mice. %Z FOR Codes: 110902 %0 Journal Article %~ PubMed %A Lim, Yun-An %A Grimm, Amandine %A Giese, Maria %A Mensah-Nyagan, Ayikoe Guy %A Villafranca, J Ernest %A Ittner, Lars M %A Eckert, Anne %A Götz, Jürgen %T Inhibition of the mitochondrial enzyme ABAD restores the amyloid-β-mediated deregulation of estradiol. %B PLoS One %D 2011 %C United States %I Public Library of Science %V 6 %N 12 %P e28887 %@ 1932-6203 %X Alzheimer''s disease (AD) is a conformational disease that is characterized by amyloid-?? (A??) deposition in the brain. A?? exerts its toxicity in part by receptor-mediated interactions that cause down-stream protein misfolding and aggregation, as well as mitochondrial dysfunction. Recent reports indicate that A?? may also interact directly with intracellular proteins such as the mitochondrial enzyme ABAD (A?? binding alcohol dehydrogenase) in executing its toxic effects. Mitochondrial dysfunction occurs early in AD, and A??''s toxicity is in part mediated by inhibition of ABAD as shown previously with an ABAD decoy peptide. Here, we employed AG18051, a novel small ABAD-specific compound inhibitor, to investigate the role of ABAD in A?? toxicity. Using SH-SY5Y neuroblastoma cells, we found that AG18051 partially blocked the A??-ABAD interaction in a pull-down assay while it also prevented the A??42-induced down-regulation of ABAD activity, as measured by levels of estradiol, a known hormone and product of ABAD activity. Furthermore, AG18051 is protective against A??42 toxicity, as measured by LDH release and MTT absorbance. Specifically, AG18051 reduced A??42-induced impairment of mitochondrial respiration and oxidative stress as shown by reduced ROS (reactive oxygen species) levels. Guided by our previous finding of shared aspects of the toxicity of A?? and human amylin (HA), with the latter forming aggregates in Type 2 diabetes mellitus (T2DM) pancreas, we determined whether AG18051 would also confer protection from HA toxicity. We found that the inhibitor conferred only partial protection from HA toxicity indicating distinct pathomechanisms of the two amyloidogenic agents. Taken together, our results present the inhibition of ABAD by compounds such as AG18051 as a promising therapeutic strategy for the prevention and treatment of AD, and suggest levels of estradiol as a suitable read-out. %Z FOR Codes: 110903 %0 Book Section %A Gotz, Jurgen %A Ittner, Lars %A Gotz, Naeman %A Lam, Hong %A Nicholas, Hannah %T Invertebrate and Vertebrate Models of Tauopathies %B Animal Models for Neurodegenerative Disease %D 2011 %C Cambridge %I RSC Publishing %V %N %P 69-85 %@ 9781849731843 %E Avila, Jesus %E Lucas, Jose %E Hernandez, Felix %X %Z FOR Codes: 60105 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Eckert, Anne %A Matamales, Miriam %A Ittner, Lars M %A Liu, Xin %T Modes of Aβ toxicity in Alzheimer's disease. %B Cellular and molecular life sciences : CMLS %D 2011 %C Switzerland %I Birkhaeuser Verlag AG %V 68 %N 20 %P 3359-75 %@ 1420-9071 %X Alzheimer''s disease (AD) is reaching epidemic proportions, yet a cure is not yet available. While the genetic causes of the rare familial inherited forms of AD are understood, the causes of the sporadic forms of the disease are not. Histopathologically, these two forms of AD are indistinguishable: they are characterized by amyloid-?? (A??) peptide-containing amyloid plaques and tau-containing neurofibrillary tangles. In this review we compare AD to frontotemporal dementia (FTD), a subset of which is characterized by tau deposition in the absence of overt plaques. A host of transgenic animal AD models have been established through the expression of human proteins with pathogenic mutations previously identified in familial AD and FTD. Determining how these mutant proteins cause disease in vivo should contribute to an understanding of the causes of the more frequent sporadic forms. We discuss the insight transgenic animal models have provided into A?? and tau toxicity, also with regards to mitochondrial function and the crucial role tau plays in mediating A?? toxicity. We also discuss the role of miRNAs in mediating the toxic effects of the A?? peptide. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Bi, Mian %A Ittner, Arne %A Ke, Yazi D %A Götz, Jürgen %A Ittner, Lars M %T Tau-Targeted Immunization Impedes Progression of Neurofibrillary Histopathology in Aged P301L Tau Transgenic Mice. %B PLoS One %D 2011 %C United States %I Public Library of Science %V 6 %N 12 %P e26860 %@ 1932-6203 %X In Alzheimer''s disease (AD) brains, the microtubule-associated protein tau and amyloid-?? (A??) deposit as intracellular neurofibrillary tangles (NFTs) and extracellular plaques, respectively. Tau deposits are furthermore found in a significant number of frontotemporal dementia cases. These diseases are characterized by progressive neurodegeneration, the loss of intellectual capabilities and behavioral changes. Unfortunately, the currently available therapies are limited to symptomatic relief. While active immunization against A?? has shown efficacy in both various AD mouse models and patients with AD, immunization against pathogenic tau has only recently been shown to prevent pathology in young tau transgenic mice. However, if translated to humans, diagnosis and treatment would be routinely done when symptoms are overt, meaning that the histopathological changes have already progressed. Therefore, we used active immunization to target pathogenic tau in 4, 8, and 18 months-old P301L tau transgenic pR5 mice that have an onset of NFT pathology at 6 months of age. In all age groups, NFT pathology was significantly reduced in treated compared to control pR5 mice. Similarly, phosphorylation of tau at pathological sites was reduced. In addition, increased astrocytosis was found in the oldest treated group. Taken together, our data suggests that tau-targeted immunization slows the progression of NFT pathology in mice, with practical implications for human patients. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Lim, Yun-An %A Rhein, Virginie %A Baysang, Ginette %A Meier, Fides %A Poljak, Anne %A J Raftery, Mark %A Guilhaus, Michael %A Ittner, Lars M %A Eckert, Anne %A Götz, Jürgen %T Abeta and human amylin share a common toxicity pathway via mitochondrial dysfunction. %B Proteomics %D 2010 %C Germany %I Wiley - VCH Verlag GmbH & Co. KGaA %V 10 %N 8 %P 1621-33 %@ 1615-9853 %X Alzheimer''s disease (AD) and type 2 diabetes mellitus (T2DM) are leading causes of morbidity and mortality in the elderly. Both diseases are characterized by amyloid deposition in target tissues: aggregation of amylin in T2DM is associated with loss of insulin-secreting beta-cells, while amyloid beta (A beta) aggregation in AD brain is associated with neuronal loss. Here, we used quantitative iTRAQ proteomics as a discovery tool to show that both A beta and human amylin (HA) deregulate identical proteins, a quarter of which are mitochondrial, supporting the notion that mitochondrial dysfunction is a common target in these two amyloidoses. A functional validation revealed that mitochondrial complex IV activity was significantly reduced after treatment with either HA or A beta, as was mitochondrial respiration. In comparison, complex I activity was reduced only after treatment with HA. A beta and HA, but not the non-amyloidogenic rat amylin, induced significant increases in the generation of ROS. Co-incubation of HA and A beta did not produce an augmented effect in ROS production, again suggesting common toxicity mechanisms. In conclusion, our data suggest that A beta and HA both exert toxicity, at least in part, via mitochondrial dysfunction, thus restoring their function may be beneficial for both AD and T2DM. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Gladbach, Amadeus %A Pennanen, Luis %A van Eersel, Janet %A Schild, Andreas %A David, Della %A Ittner, Lars M %T Animal models reveal role for tau phosphorylation in human disease. %B Biochimica et Biophysica Acta %D 2010 %C Netherlands %I Elsevier BV %V 1802 %N 10 %P 860-871 %@ 0006-3002 %X Many proteins that are implicated in human disease are posttranslationally modified. This includes the microtubule-associated protein tau that is deposited in a hyperphosphorylated form in brains of Alzheimer''s disease patients. The focus of this review article is on the physiological and pathological phosphorylation of tau; the relevance of aberrant phosphorylation for disease; the role of kinases and phosphatases in this process; its modeling in transgenic mice, flies, and worms; and implications of phosphorylation for therapeutic intervention. %Z FOR Codes: 601 601 %0 Journal Article %~ PubMed %A Ittner, Lars M %A Ke, Yazi D %A Delerue, Fabien %A Bi, Mian %A Gladbach, Amadeus %A van Eersel, Janet %A Wölfing, Heidrun %A Chieng, Billy C %A Christie, Macdonald J %A Napier, Ian A %A Eckert, Anne %A Staufenbiel, Matthias %A Hardeman, Edna %A Götz, Jürgen %T Dendritic Function of Tau Mediates Amyloid-beta Toxicity in Alzheimer's Disease Mouse Models. %B Cell %D 2010 %C United States %I Cell Press %V 142 %N 3 %P 387-397 %@ 1097-4172 %X Alzheimer''s disease (AD) is characterized by amyloid-beta (Abeta) and tau deposition in brain. It has emerged that Abeta toxicity is tau dependent, although mechanistically this link remains unclear. Here, we show that tau, known as axonal protein, has a dendritic function in postsynaptic targeting of the Src kinase Fyn, a substrate of which is the NMDA receptor (NR). Missorting of tau in transgenic mice expressing truncated tau (Deltatau) and absence of tau in tau(-/-) mice both disrupt postsynaptic targeting of Fyn. This uncouples NR-mediated excitotoxicity and hence mitigates Abeta toxicity. Deltatau expression and tau deficiency prevent memory deficits and improve survival in Abeta-forming APP23 mice, a model of AD. These deficits are also fully rescued with a peptide that uncouples the Fyn-mediated interaction of NR and PSD-95 in vivo. Our findings suggest that this dendritic role of tau confers Abeta toxicity at the postsynapse with direct implications for pathogenesis and treatment of AD. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Lim, Yun-An %A Ke, Yazi D %A Eckert, Anne %A Ittner, Lars M %T Dissecting toxicity of tau and beta-amyloid. %B Neurodegenerative Diseases %D 2010 %C Switzerland %I S. Karger AG %V 7 %N 1-3 %P 10-12 %@ 1660-2862 %X BACKGROUND: How beta-amyloid (Abeta) and tau exert toxicity in Alzheimer''s disease is only partly understood. Major questions include (1) which aggregation state of Abeta confers toxicity, (2) do amyloidogenic proteins have similar mechanisms of toxicity, and (3) does soluble tau interfere with cellular functions? METHODS: To determine Abeta toxicity in P301L mutant tau transgenic mice, mitochondrial function was assessed after insult with monomeric, oligomeric and fibrillar Abeta. Amylin and Abeta toxicity were compared in cortical and hippocampal long-term cultures. To determine tau toxicity, K369I mutant tau mice were established as a model of frontotemporal dementia, analyzed biochemically and compared with human diseased brain. RESULTS: Oligomeric and fibrillar Abeta42 were both toxic, although to different degrees. Human amylin shared toxicity with Abeta42, an effect not observed for nonamyloidogenic rat amylin. Clinical features of K369I tau mice were caused by aberrant interaction of phosphorylated tau with JIP1, a component of the kinesin transport machinery. CONCLUSION: Our data support the notion of a synergistic action of tau and Abeta pathology on mitochondria. A specific conformation of Abeta42 and human amylin determines toxicity. Finally, trapping of JIP1 by phosphorylated tau in the neuronal soma emerges as a fundamental pathomechanism in neurodegeneration. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Krupka, Niklas %A Strappe, Padraig %A Götz, Jürgen %A Ittner, Lars M %T Gateway-compatible lentiviral transfer vectors for ubiquitin promoter driven expression of fluorescent fusion proteins. %B Plasmid %D 2010 %C United States %I Academic Press %V 63 %N 3 %P 155-160 %@ 1095-9890 %X Lentiviral gene delivery has become widely used. Similarly, the Gateway cloning technology that allows restriction-independent cloning of genes into target vectors is becoming increasingly popular. Here, we have generated two Gateway-compatible lentiviral transfer vectors for expression of carboxy-terminal fluorescence tagged fusion proteins, pLVU/GFP and pLVU/RED. We used a restriction enzyme-independent PCR-based approach to introduce the carboxy-terminal fluorescence tags, EmGFP and DsRed, respectively. Both vectors combine the advantages of restriction enzyme/ligation-independent cloning using the Gateway system with a attR1-CmR-ccdB-attR2 recombination cassette, together with expression of fluorescence tagged fusion proteins driven by the robust mammalian ubiquitin C (UbC) promoter. We tested the vectors by expressing different proteins together with the carboxy-terminal fluorescence tags in 293T and SH-SY5Y cells. Both pLVU/GFP and pLVU/RED can be utilized in different experiments, including protein localization studies and live-cell in vivo imaging. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Schonrock, Nicole %A Ke, Yazi D %A Humphreys, David %A Staufenbiel, Matthias %A Ittner, Lars M %A Preiss, Thomas %A Götz, Jürgen %T Neuronal MicroRNA Deregulation in Response to Alzheimer's Disease Amyloid-beta. %B PLoS One %D 2010 %C United States %I Public Library of Science %V 5 %N 6 %P e11070 %@ 1932-6203 %X Normal brain development and function depends on microRNA (miRNA) networks to fine tune the balance between the transcriptome and proteome of the cell. These small non-coding RNA regulators are highly enriched in brain where they play key roles in neuronal development, plasticity and disease. In neurodegenerative disorders such as Alzheimer''s disease (AD), brain miRNA profiles are altered; thus miRNA dysfunction could be both a cause and a consequence of disease. Our study dissects the complexity of human AD pathology, and addresses the hypothesis that amyloid-beta (Abeta) itself, a known causative factor of AD, causes neuronal miRNA deregulation, which could contribute to the pathomechanisms of AD. We used sensitive TaqMan low density miRNA arrays (TLDA) on murine primary hippocampal cultures to show that about half of all miRNAs tested were down-regulated in response to Abeta peptides. Time-course assays of neuronal Abeta treatments show that Abeta is in fact a powerful regulator of miRNA levels as the response of certain mature miRNAs is extremely rapid. Bioinformatic analysis predicts that the deregulated miRNAs are likely to affect target genes present in prominent neuronal pathways known to be disrupted in AD. Remarkably, we also found that the miRNA deregulation in hippocampal cultures was paralleled in vivo by a deregulation in the hippocampus of Abeta42-depositing APP23 mice, at the onset of Abeta plaque formation. In addition, the miRNA deregulation in hippocampal cultures and APP23 hippocampus overlaps with those obtained in human AD studies. Taken together, our findings suggest that neuronal miRNA deregulation in response to an insult by Abeta may be an important factor contributing to the cascade of events leading to AD. %Z FOR Codes: 1109 %0 Journal Article %~ PubMed %A van Eersel, Janet %A Ke, Yazi D %A Liu, Xin %A Delerue, Fabien %A Kril, Jillian J %A Götz, Jürgen %A Ittner, Lars M %T Sodium selenate mitigates tau pathology, neurodegeneration, and functional deficits in Alzheimer's disease models. %B Proceedings of the National Academy of Sciences of the United States of America %D 2010 %C United States %I National Academy of Sciences %V 107 %N 31 %P 13888-13893 %@ 0027-8424 %X Alzheimer''s disease (AD) brains are characterized by amyloid-beta-containing plaques and hyperphosphorylated tau-containing neurofibrillary tangles (NFTs); however, in frontotemporal dementia, the tau pathology manifests in the absence of overt amyloid-beta plaques. Therapeutic strategies so far have primarily been targeting amyloid-beta, although those targeting tau are only slowly beginning to emerge. Here, we identify sodium selenate as a compound that reduces tau phosphorylation both in vitro and in vivo. Importantly, chronic oral treatment of two independent tau transgenic mouse strains with NFT pathology, P301L mutant pR5 and K369I mutant K3 mice, reduces tau hyperphosphorylation and completely abrogates NFT formation. Furthermore, treatment improves contextual memory and motor performance, and prevents neurodegeneration. As hyperphosphorylation of tau precedes NFT formation, the effect of selenate on tau phosphorylation was assessed in more detail, a process regulated by both kinases and phosphatases. A major phosphatase implicated in tau dephosphorylation is the serine/threonine-specific protein phosphatase 2A (PP2A) that is reduced in both levels and activity in the AD brain. We found that selenate stabilizes PP2A-tau complexes. Moreover, there was an absence of therapeutic effects in sodium selenate-treated tau transgenic mice that coexpress a dominant-negative mutant form of PP2A, suggesting a mediating role for PP2A. Taken together, sodium selenate mitigates tau pathology in several AD models, making it a promising lead compound for tau-targeted treatments of AD and related dementias. %Z FOR Codes: 110903 30406 110316 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Schonrock, Nicole %A Vissel, Bryce %A Ittner, Lars M %T Alzheimer's Disease Selective Vulnerability and Modelling in Transgenic Mice. %B Journal of Alzheimer's disease : JAD %D 2009 %C Netherlands %I IOS Press %V 18 %N 2 %P 243-51 %@ 1387-2877 %X Neurodegenerative diseases are characterized by ''hot spots'' of degeneration. The regions of primary vulnerability vary between different neurodegenerative diseases. Within these regions, some neurons are lost whereas others that are morphologically indiscriminate survive. The enigma of this selective vulnerability is tightly linked to two fundamental problems in the neurosciences. First, it is not understood how many neuronal cell types make up the mammalian brain; estimates are in the order of more than a thousand. Second, the mechanisms by which some nerve cells undergo functional impairment followed by degeneration while others do not, remain elusive. Understanding the basis for this selective vulnerability has significant implications for understanding the pathogenesis of disease and for developing treatments. Here, we review what is known about selective vulnerability in Alzheimer''s disease, frontotemporal dementia, and Parkinson''s disease. We suggest, since transgenic animal models of disease reproduce aspects of selective vulnerability, that these models offer a valuable system for future investigations into the physiological basis of selective vulnerability. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Rhein, Virginie %A Song, Xiaomin %A Wiesner, Andreas %A Ittner, Lars M %A Baysang, Ginette %A Meier, Fides %A Ozmen, Laurence %A Bluethmann, Horst %A Dröse, Stefan %A Brandt, Ulrich %A Savaskan, Egemen %A Czech, Christian %A Götz, Jürgen %A Eckert, Anne %T Amyloid-beta and tau synergistically impair the oxidative phosphorylation system in triple transgenic Alzheimer's disease mice. %B Proceedings of the National Academy of Sciences of the United States of America %D 2009 %C United States %I National Academy of Sciences %V 106 %N 47 %P 20057-20062 %@ 0027-8424 %X Alzheimer''s disease (AD) is characterized by amyloid-beta (Abeta)-containing plaques, neurofibrillary tangles, and neuron and synapse loss. Tangle formation has been reproduced in P301L tau transgenic pR5 mice, whereas APP(sw)PS2(N141I) double-transgenic APP152 mice develop Abeta plaques. Cross-breeding generates triple transgenic ((triple)AD) mice that combine both pathologies in one model. To determine functional consequences of the combined Abeta and tau pathologies, we performed a proteomic analysis followed by functional validation. Specifically, we obtained vesicular preparations from (triple)AD mice, the parental strains, and nontransgenic mice, followed by the quantitative mass-tag labeling proteomic technique iTRAQ and mass spectrometry. Within 1,275 quantified proteins, we found a massive deregulation of 24 proteins, of which one-third were mitochondrial proteins mainly related to complexes I and IV of the oxidative phosphorylation system (OXPHOS). Notably, deregulation of complex I was tau dependent, whereas deregulation of complex IV was Abeta dependent, both at the protein and activity levels. Synergistic effects of Abeta and tau were evident in 8-month-old (triple)AD mice as only they showed a reduction of the mitochondrial membrane potential at this early age. At the age of 12 months, the strongest defects on OXPHOS, synthesis of ATP, and reactive oxygen species were exhibited in the (triple)AD mice, again emphasizing synergistic, age-associated effects of Abeta and tau in perishing mitochondria. Our study establishes a molecular link between Abeta and tau protein in AD pathology in vivo, illustrating the potential of quantitative proteomics. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Götz, J %A Ittner, L M %A Lim, Y-A %T Common features between diabetes mellitus and Alzheimer's disease. %B Cellular and molecular life sciences %D 2009 %C Switzerland %I Birkhaeuser Verlag AG %V 66 %N 8 %P 1321-1325 %@ 1420-9071 %X Epidemiological studies establish a link between Type 2 diabetes (T2DM) and Alzheimer''s disease (AD), both leading causes of morbidity and mortality in the elderly. These diseases also share clinical and biochemical features suggesting common pathogenic mechanisms. Specifically, both are amyloidoses as they are characterized by fibrillar protein aggregates - amylin in T2DM pancreatic islets, and beta-amyloid (Abeta) and neurofibrillary tangles (NFTs) in AD brain. Amylin aggregation is associated with pancreatic beta-cell loss, and Abeta and NFT formation with neuronal cell loss. We discuss the possibility that amylin and Abeta exert their toxicity by similar mechanisms, with components of the pathocascades shared, and that therapies based on amyloidogenic properties are beneficial for both T2DM and AD. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Ke, Yazi D %A Delerue, Fabien %A Gladbach, Amadeus %A Götz, Jürgen %A Ittner, Lars M %T Experimental Diabetes Mellitus Exacerbates Tau Pathology in a Transgenic Mouse Model of Alzheimer's Disease. %B PLoS One %D 2009 %C United States %I Public Library of Science %V 4 %N 11 %P e7917 %@ 1932-6203 %X Diabetes mellitus (DM) is characterized by hyperglycemia caused by a lack of insulin, insulin resistance, or both. There is increasing evidence that insulin also plays a role in Alzheimer''s disease (AD) as it is involved in the metabolism of beta-amyloid (Abeta) and tau, two proteins that form Abeta plaques and neurofibrillary tangles (NFTs), respectively, the hallmark lesions in AD. Here, we examined the effects of experimental DM on a pre-existing tau pathology in the pR5 transgenic mouse strain that is characterized by NFTs. pR5 mice express P301L mutant human tau that is associated with dementia. Experimental DM was induced by administration of streptozotocin (STZ), which causes insulin deficiency. We determined phosphorylation of tau, using immunohistochemistry and Western blotting. Solubility of tau was determined upon extraction with sarkosyl and formic acid, and Gallyas silver staining was employed to reveal NFTs. Insulin depletion by STZ administration in six months-old non-transgenic mice causes increased tau phosphorylation, without its deposition or NFT formation. In contrast, in pR5 mice this results in massive deposition of hyperphosphorylated, insoluble tau. Furthermore, they develop a pronounced tau-histopathology, including NFTs at this early age, while the pathology in sham-treated pR5 mice is moderate. Whereas experimental DM did not result in deposition of hyperphosphorylated tau in non-transgenic mice, a predisposition to develop a tau pathology in young pR5 mice was both sufficient and necessary to exacerbate tau deposition and NFT formation. Hence, DM can accelerate onset and increase severity of disease in individuals with a predisposition to developing tau pathology. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Ittner, Lars M %A Ke, Yazi D %A Gotz, Jurgen %T Phosphorylated tau interacts with c-JUN N-terminal kinase (JNK) interacting protein 1 (JIP1) in Alzheimer's disease. %B The Journal of biological chemistry %D 2009 %C United States %I American Society for Biochemistry and Molecular Bi %V 284 %N 31 %P 20909-16 %@ 1083-351X %X In Alzheimer disease (AD) and frontotemporal dementia the microtubule-associated protein Tau becomes progressively hyperphosphorylated, eventually forming aggregates. However, how Tau dysfunction is associated with functional impairment is only partly understood, especially at early stages when Tau is mislocalized but has not yet formed aggregates. Impaired axonal transport has been proposed as a potential pathomechanism, based on cellular Tau models and Tau transgenic mice. We recently reported K369I mutant Tau transgenic K3 mice with axonal transport defects that suggested a cargo-selective impairment of kinesin-driven anterograde transport by Tau. Here, we show that kinesin motor complex formation is disturbed in the K3 mice. We show that under pathological conditions hyperphosphorylated Tau interacts with c-Jun N-terminal kinase- interacting protein 1 (JIP1), which is associated with the kinesin motor protein complex. As a result, transport of JIP1 into the axon is impaired, causing JIP1 to accumulate in the cell body. Because we found trapping of JIP1 and a pathological Tau/JIP1 interaction also in AD brain, this may have pathomechanistic implications in diseases with a Tau pathology. This is supported by JIP1 sequestration in the cell body of Tau-transfected primary neuronal cultures. The pathological Tau/JIP1 interaction requires phosphorylation of Tau, and Tau competes with the physiological binding of JIP1 to kinesin light chain. Because JIP1 is involved in regulating cargo binding to kinesin motors, our findings may, at least in part, explain how hyperphosphorylated Tau mediates impaired axonal transport in AD and frontotemporal dementia. %Z FOR Codes: 110904 %0 Journal Article %~ PubMed %A van Eersel, Janet %A Bi, Mian %A Ke, Yazi %A Hodges, John %A Xuereb, John %A Gregory, Gillian %A Halliday, Glenda %A Götz, Jürgen %A Kril, Jillian %A Ittner, Lars %T Phosphorylation of soluble tau differs in Pick's disease and Alzheimer's disease brains. %B Journal of Neural Transmission %D 2009 %C Austria %I Springer Wien %V 116 %N 10 %P 1243-1251 %@ 1435-1463 %X Frontotemporal lobar degeneration (FTLD) is a common cause of presenile dementia characterised by behavioural and language disturbances. Pick''s disease (PiD) is a subtype of FTLD, which presents with intraneuronal inclusions consisting of hyperphosphorylated tau protein aggregates. Although Alzheimer''s disease (AD) is also characterised by tau lesions, these are both histologically and biochemically distinct from the tau aggregates found in PiD. What determines the distinct characteristics of these tau lesions is unknown. As phosphorylated, soluble tau has been suggested to be the precursor of tau aggregates, we compared both the level and phosphorylation profile of tau in tissue extracts of AD and PiD brains to determine whether the differences in the tau lesions are reflected by differences in soluble tau. Levels of soluble tau were decreased in AD but not PiD. In addition, soluble tau was phosphorylated to a greater extent in AD than in PiD and displayed a different phosphorylation profile in the two disorders. Consistently, tau kinases were activated to different degrees in AD compared with PiD. Such differences in solubility and phosphorylation may contribute, at least in part, to the formation of distinct tau deposits, but may also have implications for the clinical differences between AD and PiD. %Z FOR Codes: 110308 60105 110316 %0 Journal Article %~ PubMed %A Fath, Thomas %A Ke, Yazi D %A Gunning, Peter %A Götz, Jürgen %A Ittner, Lars M %T Primary support cultures of hippocampal and substantia nigra neurons. %B Nature protocols %D 2009 %C United Kingdom %I Nature Publishing Group %V 4 %N 1 %P 78-85 %@ 1750-2799 %X Primary cultures of rat and murine hippocampal neurons are widely used to reveal cellular mechanisms in neurobiology. Their use is limited, as culturing at low density is often not possible or is dependent on sophisticated methods. Here we present a novel method for culturing embryonic (E16.5) murine hippocampal neurons, using a spatially separated ring of cortical neurons for neurotrophic support. This method allows long-term cultures at a very low cell density, and therefore, the study of single embryo preparations and isolated neurons. This method has been adopted for neurons from the substantia nigra (E16.5), with support from a ring of striatal neurons. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A G??tz, J??rgen %A Ittner, Lars %A Lim, Yun-An %T Response to the comment 'Iron, type 2 diabetes mellitus, and Alzheimer's disease' to our Visions and Reflections article 'Common features between diabetes mellitus and Alzheimer's disease' %B Cellular and Molecular Life Sciences %D 2009 %C Switzerland %I Birkhaeuser Verlag AG %V 66 %N 17 %P 2945 %@ 1420-9071 %X %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Deters, Natasha %A Ittner, Lars M %A Götz, Jürgen %T Substrate-specific reduction of PP2A activity exaggerates tau pathology. %B Biochemical and biophysical research communications %D 2009 %C United States %I Academic Press Inc Elsevier Science %V 379 %N 2 %P 400-405 %@ 1090-2104 %X Phosphorylation of the microtubule-associated protein tau is regulated by the balanced interplay of kinases and phosphatases. Disturbance of this balance causes hyperphosphorylation of tau and neurofibrillary tangle formation in Alzheimer''s disease brain. Here, we crossed Dom5 mice that express a substrate-specific dominant negative mutant form, L309A Calpha, of protein phosphatase 2A (PP2A) with neurofibrillary-tangle-forming P301L mutant tau transgenic pR5 mice. This exacerbated the tau pathology of pR5 mice significantly. Double-transgenic Dom5/pR5 mice showed 7-fold increased numbers of hippocampal neurons that specifically phosphorylated the pathological S422 epitope of tau. They showed 8-fold increased numbers of tangles compared to pR5 mice, in agreement with our previous finding that tangle formation is correlated with and preceded by phosphorylation of tau at the S422 epitope. This suggests that, in addition to kinases, PP2A and its regulatory subunits may be a therapeutic target for Alzheimer''s disease. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Scarf, Alana M %A Ittner, Lars M %A Kassiou, Michael %T The translocator protein (18 kDa): central nervous system disease and drug design. %B Journal of Medicinal Chemistry %D 2009 %C United States %I American Chemical Society %V 52 %N 3 %P 581-592 %@ 0022-2623 %X %Z FOR Codes: 30401 30403 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Ittner, Lars M %A Schonrock, Nicole %A Cappai, Roberto %T An update on the toxicity of Abeta in Alzheimer's disease. %B Neuropsychiatric disease and treatment %D 2008 %C New Zealand %I Dove Medical Press Ltd %V 4 %N 6 %P 1033-1042 %@ 1176-6328 %X Alzheimer''s disease is characterized histopathologically by deposition of insoluble forms of the peptide Abeta and the protein tau in brain. Abeta is the principal component of amyloid plaques and tau of neurofibrillary tangles. Familial cases of AD are associated with causal mutations in the gene encoding the amyloid precursor protein, APP, from which the amyloidogenic Abeta peptide is derived, and this supports a role for Abeta in disease. Abeta can promote tau pathology and at the same time its toxicity is also tau-dependent. Abeta can adopt different conformations including soluble oligomers and insoluble fibrillar species present in plaques. We discuss which of these conformations exert toxicity, highlight molecular pathways involved and discuss what has been learned by applying functional genomics. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Ittner, Lars M %T Animal models of Alzheimer's disease and frontotemporal dementia. %B Nature Reviews. Neuroscience %D 2008 %C United Kingdom %I Nature Publishing Group %V 9 %N 7 %P 532-544 %@ 1471-0048 %X Insoluble protein aggregates have been linked to Alzheimer''s disease (AD) and frontotemporal dementia (FTD). Recent work in transgenic mice has shed light on the role of these aggregates by identifying soluble oligomeric species that may interfere with essential cellular mechanisms at an early disease stage. This review summarizes what we have learned about the roles of these proteins from transgenic mice and invertebrate species such as flies and worms. Proteomic and transcriptomic analyses of tissue from these animal models have identified new molecules with crucial roles in disease. Moreover, transgenic animals have been instrumental in defining drug targets and designing novel therapeutic strategies. With advanced imaging techniques that can be used in both humans and mice an early, preclinical diagnosis of AD and FTD could be within reach. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Falk, Sven %A Wurdak, Heiko %A Ittner, Lars M %A Ille, Fabian %A Sumara, Grzegorz %A Schmid, Marie-Theres %A Draganova, Kalina %A Lang, Karl S %A Paratore, Christian %A Leveen, Per %A Suter, Ueli %A Karlsson, Stefan %A Born, Walter %A Ricci, Romeo %A Götz, Magdalena %A Sommer, Lukas %T Brain area-specific effect of TGF-beta signaling on Wnt-dependent neural stem cell expansion. %B Cell Stem Cell %D 2008 %C United States %I Cell Press %V 2 %N 5 %P 472-483 %@ 1875-9777 %X Regulating the choice between neural stem cell maintenance versus differentiation determines growth and size of the developing brain. Here we identify TGF-beta signaling as a crucial factor controlling these processes. At early developmental stages, TGF-beta signal activity is localized close to the ventricular surface of the neuroepithelium. In the midbrain, but not in the forebrain, Tgfbr2 ablation results in ectopic expression of Wnt1/beta-catenin and FGF8, activation of Wnt target genes, and increased proliferation and horizontal expansion of neuroepithelial cells due to shortened cell-cycle length and decreased cell-cycle exit. Consistent with this phenotype, self-renewal of mutant neuroepithelial stem cells is enhanced in the presence of FGF and requires Wnt signaling. Moreover, TGF-beta signal activation counteracts Wnt-induced proliferation of midbrain neuroepithelial cells. Thus, TGF-beta signaling controls the size of a specific brain area, the dorsal midbrain, by antagonizing canonical Wnt signaling and negatively regulating self-renewal of neuroepithelial stem cells. %Z FOR Codes: 60105 %0 Journal Article %~ PubMed %A Deters, Natasha %A Ittner, Lars M %A Götz, Jürgen %T Divergent phosphorylation pattern of tau in P301L tau transgenic mice. %B The European Journal of Neuroscience %D 2008 %C United Kingdom %I Blackwell Publishing Ltd %V 28 %N 1 %P 137-147 %@ 0953-816X %X Aggregates of hyperphosphorylated tau are prominent in brains of patients with Alzheimer''s disease or frontotemporal dementia (FTD). They have been reproduced in animal models following the identification of tau mutations in familial cases of FTD. This includes our previously generated transgenic model, pR5, which expresses FTD (P301L) mutant tau in neurons. The mice are characterized by tau aggregation including tangle (NFT) formation, memory impairment and mitochondrial dysfunction. In 8-month-old mice, S422 phosphorylation of tau is linked to NFT formation, however, a detailed analysis of tau solubility, phosphorylation and aggregation has not been done nor have the mice been monitored until a high age. Here, we undertook an analysis by immunohistochemistry, Gallyas impregnation and Western blotting of brains from 3 month- up to 20 month-old mice. NFTs first appeared at 6 months in the amygdala, followed by the CA1 region of the hippocampus. As the mice get older, the solubility of tau is decreased as determined by sequential extractions. Histological analysis revealed increased phosphorylation at the AT180, AT270 and 12E8 epitopes with ageing. The numbers of AT8-positive neurons increased from 3 to 6 months old. However, whereas S422 appeared only late and concomitantly with NFT formation, the only neurons left with AT8-reactivity at 20 months were those that had undergone NFT formation. As hyperphosphorylated tau continued to accumulate, the lack of AT8-reactivity suggests regulatory mechanisms in specifically dephosphorylating the AT8 epitope in the remaining neurons. Thus, differential regulation of phosphorylation is important for NFT formation in neurodegenerative diseases with tau pathology. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Götz, Jürgen %A David, Della %A Hoerndli, Frederic %A Ke, Yazi D %A Schonrock, Nicole %A Wiesner, Andreas %A Fath, Thomas %A Bokhari, Laita %A Lim, Yun-An %A Deters, Natasha %A Ittner, Lars M %T Functional genomics dissects pathomechanisms in tauopathies: mitosis failure and unfolded protein response. %B Neuro-Degenerative Diseases %D 2008 %C Switzerland %I S. Karger AG %V 5 %N 3-4 %P 179-181 %@ 1660-2862 %X BACKGROUND: Alzheimer''s disease (AD) is characterized by beta-amyloid (Abeta) peptide-containing plaques and tau-containing neurofibrillary tangles. By intracerebral injection of Abeta(42), both pathologies have been combined in P301L tau mutant mice. Furthermore, in cell culture, Abeta(42) induces tau aggregation. While both Abeta(42) and mutant tau cause neuronal dysfunction, their modes of action are only vaguely understood. METHODS: To determine which processes are disrupted by Abeta(42) and/or P301L mutant tau, we used transcriptomic and proteomic techniques followed by functional validation and analysis of human AD tissue. RESULTS: Our transcriptomic study in the SH-SY5Y cell culture system revealed that Abeta(42) and P301L tau expression independently affect genes controlling the cell cycle and cell proliferation. Proteomics applied to Abeta(42)-treated P301L tau-expressing SH-SY5Y cells and the amygdala of Abeta(42)-injected P301L transgenic mice revealed that a significant fraction of proteins altered in both systems belonged to the same functional categories, i.e. stress response and metabolism. Among the proteins identified was valosin-containing protein (VCP), a component of the quality control system during endoplasmic reticulum stress. Mutations in VCP have recently been linked to frontotemporal dementia. CONCLUSION: Our data support the mitosis failure hypothesis that claims that aberrant cell cycle reentry of postmitotic neurons induces apoptosis. Furthermore, our data underline a role of Abeta(42) in the stress response associated with protein folding. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Lim, Yun-An %A Ittner, Lars M %A Lim, Yun Li %A Götz, Jürgen %T Human but not rat amylin shares neurotoxic properties with Abeta42 in long-term hippocampal and cortical cultures. %B FEBS letters %D 2008 %C Netherlands %I Elsevier Science Bv %V 582 %N 15 %P 2188-94 %@ 0014-5793 %X Type 2 diabetes mellitus (DM) and Alzheimer''s disease (AD) share epidemiological and biochemical features. Both are characterized by insoluble protein aggregates with a fibrillar conformation--amylin in Type 2 DM pancreatic islets, and Abeta in AD brain. To determine whether amylin shares neurotoxic properties with Abeta, we incubated hippocampal and cortical neurons with Abeta42 and human amylin. Different from non-amyloidogenic rat amylin, both caused a dose-, time- and cell type-specific neurotoxicity supporting the notion of a similar toxic mechanism. Depending on the cell type, this finding is also supported by co-incubation of human amylin and Abeta. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Ittner, Lars M %A Fändrich, Marcus %A Schonrock, Nicole %T Is tau aggregation toxic or protective: a sensible question in the absence of sensitive methods? %B Journal of Alzheimer's disease %D 2008 %C Netherlands %I IOS Press %V 14 %N 4 %P 423-9 %@ 1387-2877 %X In Alzheimer''s disease brain, the microtubule-associated protein tau detaches from the microtubules, pathologically interacts with cellular proteins, and eventually forms insoluble aggregates that also bind and trap a myriad of proteins. As these proteins are depleted from the cellular pool, they are unavailable for physiological functions. Thus elevated tau levels are pathogenic, even in the absence of tau aggregation. Whereas it is reasonable to assume that tau aggregation is toxic during late stages of disease, the question arises whether early in disease it may be protective. This question can be addressed in tau transgenic animal models in which tau aggregation has been correlated with behavioral impairment. We discuss ways of how tau aggregation is monitored in these mice and what the detection limits are of these methods. We conclude that new tools are needed to measure the different stages of tau aggregation. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Ittner, Lars M %A Fath, Thomas %A Ke, Yazi D %A Bi, Mian %A van Eersel, Janet %A Li, Kong M %A Gunning, Peter %A Götz, Jürgen %T Parkinsonism and impaired axonal transport in a mouse model of frontotemporal dementia. %B Proceedings of the National Academy of Sciences of the United States of America %D 2008 %C United States %I National Academy of Sciences %V 105 %N 41 %P 15997-6002 %@ 1091-6490 %X Frontotemporal dementia (FTD) is characterized by cognitive and behavioral changes and, in a significant subset of patients, Parkinsonism. Histopathologically, FTD frequently presents with tau-containing lesions, which in familial cases result from mutations in the MAPT gene encoding tau. Here we present a novel transgenic mouse strain (K3) that expresses human tau carrying the FTD mutation K369I. K3 mice develop a progressive histopathology that is reminiscent of that in human FTD with the K369I mutation. In addition, K3 mice show early-onset memory impairment and amyotrophy in the absence of overt neurodegeneration. Different from our previously generated tau transgenic strains, the K3 mice express the transgene in the substantia nigra (SN) and show an early-onset motor phenotype that reproduces Parkinsonism with tremor, bradykinesia, abnormal gait, and postural instability. Interestingly, motor performance of young, but not old, K3 mice improves upon L-dopa treatment, which bears similarities to Parkinsonism in FTD. The early-onset symptoms in the K3 mice are mechanistically related to selectively impaired anterograde axonal transport of distinct cargos, which precedes the loss of dopaminergic SN neurons that occurs in aged mice. The impaired axonal transport in SN neurons affects, among others, vesicles containing the dopamine-synthesizing enzyme tyrosine hydroxylase. Distinct modes of transport are also impaired in sciatic nerves, which may explain amyotrophy. Together, the K3 mice are a unique model of FTD-associated Parkinsonism, with pathomechanistic implications for the human pathologic process. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Ittner, Lars M %A Schwerdtfeger, Kerstin %A Kunz, Thomas H %A Muff, Roman %A Husmann, Knut %A Grimm, Christian %A Hafezi, Farhad %A Lang, Karl S %A Kurrer, Michael O %A Götz, Jürgen %A Born, Walter %A Fischer, Jan A %T Transgenic mice with ocular overexpression of an adrenomedullin receptor reflect human acute angle-closure glaucoma. %B Clinical science %D 2008 %C United Kingdom %I Portland Press Ltd %V 114 %N 1 %P 49-58 %@ 1470-8736 %X Glaucoma, frequently associated with high IOP (intra-ocular pressure), is a leading cause of blindness, characterized by a loss of retinal ganglion cells and the corresponding optic nerve fibres. In the present study, acutely and transiently elevated IOP, characteristic of acute angle-closure glaucoma in humans, was observed in CLR (calcitonin receptor-like receptor) transgenic mice between 1 and 3 months of age. Expression of CLR under the control of a smooth muscle alpha-actin promoter in these mice augmented signalling of the smooth-muscle-relaxing peptide adrenomedullin in the pupillary sphincter muscle and resulted in pupillary palsy. Elevated IOP was prevented in CLR transgenic mice when mated with hemizygote adrenomedullin-deficient mice with up to 50% lower plasma and organ adrenomedullin concentrations. This indicates that endogenous adrenomedullin of iris ciliary body origin causes pupillary palsy and angle closure in CLR transgenic mice overexpressing adrenomedullin receptors in the pupillary sphincter muscle. In human eyes, immunoreactive adrenomedullin has also been detected in the ciliary body. Furthermore, the CLR and RAMP2 (receptor-activity-modifying protein 2), constituting adrenomedullin receptor heterodimers, were identified in the human pupillary sphincter muscle. Thus, in humans, defective regulation of adrenomedullin action in the pupillary sphincter muscle, provoked in the present study in CLR transgenic mice, may cause acute and chronic atony and, thereby, contribute to the development of angle-closure glaucoma. The CLR transgenic mice used in the present study provide a model for acute angle-closure glaucoma. %Z FOR Codes: 111301 %0 Journal Article %~ PubMed %A Götz, Jürgen %A Deters, Natasha %A Doldissen, Amy %A Bokhari, Laita %A Ke, Yazi %A Wiesner, Andreas %A Schonrock, Nicole %A Ittner, Lars M %T A decade of tau transgenic animal models and beyond. %B Brain pathology (Zurich, Switzerland) %D 2007 %C USA %I Wiley-Blackwell Publishing %V 17 %N 1 %P 91-103 %@ 1015-6305 %X The first tau transgenic mouse model was established more than a decade ago. Since then, much has been learned about the role of tau in Alzheimer''s disease and related disorders. Animal models, both in vertebrates and invertebrates, were significantly improved and refined as a result of the identification of pathogenic mutations in Tau in human cases of frontotemporal dementia. They have been instrumental for dissecting the cross-talk between tau and the second hallmark lesion of Alzheimer''s disease, the Abeta peptide-containing amyloid plaque. We discuss how the tau models have been used to unravel the pathophysiology of Alzheimer''s disease, to search for disease modifiers and to develop novel treatment strategies. While tau has received less attention than Abeta, it is rapidly acquiring a more prominent position and the emerging view is one of a synergistic action of Abeta and tau in Alzheimer''s disease. Moreover, the existence of a number of neurodegenerative diseases with tau pathology in the absence of extracellular deposits underscores the relevance of research on tau. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Kunz, Thomas H %A Scott, Michelle %A Ittner, Lars M %A Fischer, Jan A %A Born, Walter %A Vogel, Johannes %T Calcitonin gene-related peptide-evoked sustained tachycardia in calcitonin receptor-like receptor transgenic mice is mediated by sympathetic activity. %B American Journal of Physiology: Heart and Circulatory Physiology %D 2007 %C United States %I American Physiological Society %V 293 %N 4 %P H2155-H160 %@ 0363-6135 %X Calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) are potent vasodilators and exert positive chronotropic and inotropic effects on the heart. Receptors for CGRP and AM are calcitonin receptor-like receptor (CLR)/receptor-activity-modifying protein (RAMP) 1 and CLR/RAMP2 heterodimers, respectively. The present study was designed to delineate distinct cardiovascular effects of CGRP and AM. Thus a V5-tagged rat CLR was expressed in transgenic mice in the vascular musculature, a recognized target of CGRP. Interestingly, basal arterial pressure and heart rate were indistinguishable in transgenic mice and in control littermates. Moreover, intravenous injection of 2 nmol/kg CGRP, unlike 2 nmol/kg AM, decreased arterial pressure equally by 18 +/- 5 mmHg in transgenic and control animals. But the concomitant increase in heart rate evoked by CGRP was 3.7 times higher in transgenic mice than in control animals. The effects of CGRP in transgenic and control mice, different from a decrease in arterial pressure in response to 20 nmol/kg AM, were suppressed by 2 micromol/kg of the CGRP antagonist CGRP(8-37). Propranolol, in contrast to hexamethonium, blocked the CGRP-evoked increase in heart rate in both transgenic and control animals. This was consistent with the immunohistochemical localization of the V5-tagged CLR in the superior cervical ganglion of transgenic mice. In conclusion, hypotension evoked by CGRP in transgenic and control mice was comparable and CGRP was more potent than AM. Unexpectedly, the CLR/RAMP CGRP receptor overexpressed in postganglionic sympathetic neurons of transgenic mice enhanced the positive chronotropic action of systemic CGRP. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Stanescu, D %A Iseli, H P %A Schwerdtfeger, K %A Ittner, L M %A Remé, C E %A Hafezi, F %T Continuous expression of the homeobox gene Pax6 in the ageing human retina. %B Eye %D 2007 %C United Kingdom %I Nature Publishing Group %V 21 %N 1 %P 90-93 %@ 0950-222X %X In the past few years, the essential role of the homeobox gene Pax6 for eye development has been demonstrated unambiguously in a variety of species including humans. In humans, Pax6 mutations lead to a variety of ocular malformations of the anterior and posterior segment. However, little is known about PAX6 expression in the adult human retina. We have therefore investigated PAX6 levels and localization in the human retina at various ages. %Z FOR Codes: 111301 60103 %0 Journal Article %~ PubMed %A Kunz, Thomas H %A Mueller-Steiner, Sarah %A Schwerdtfeger, Kerstin %A Kleinert, Peter %A Troxler, Heinz %A Kelm, Jens M %A Ittner, Lars M %A Fischer, Jan A %A Born, Walter %T Interaction of receptor-activity-modifying protein1 with tubulin. %B Biochimica et biophysica acta %D 2007 %C Netherlands %I Elsevier BV %V 1770 %N 8 %P 1145-1150 %@ 0006-3002 %X Receptor-activity-modifying protein (RAMP) 1 is an accessory protein of the G protein-coupled calcitonin receptor-like receptor (CLR). The CLR/RAMP1 heterodimer defines a receptor for the potent vasodilatory calcitonin gene-related peptide. A wider tissue distribution of RAMP1, as compared to that of the CLR, is consistent with additional biological functions. Here, glutathione S-transferase (GST) pull-down, coimmunoprecipitation and yeast two-hybrid experiments identified beta-tubulin as a novel RAMP1-interacting protein. GST pull-down experiments indicated interactions between the N- and C-terminal domains of RAMP1 and beta-tubulin. Yeast two-hybrid experiments confirmed the interaction between the N-terminal region of RAMP1 and beta-tubulin. Interestingly, alpha-tubulin was co-extracted with beta-tubulin in pull-down experiments and immunoprecipitation of RAMP1 coprecipitated alpha- and beta-tubulin. Confocal microscopy indicated colocalization of RAMP1 and tubulin predominantly in axon-like processes of neuronal differentiated human SH-SY5Y neuroblastoma cells. In conclusion, the findings point to biological roles of RAMP1 beyond its established interaction with G protein-coupled receptors. %Z FOR Codes: 60106 110902 %0 Journal Article %~ PubMed %A Ittner, Lars M %A Götz, Jürgen %T Pronuclear injection for the production of transgenic mice. %B Nature protocols %D 2007 %C United Kingdom %I Nature Publishing Group %V 2 %N 5 %P 1206-1215 %@ 1750-2799 %X Transgenic mice have been instrumental in dissecting the role of various neuronal proteins under both physiological and pathological conditions. Pronuclear injection is the most widely used protocol for the generation of transgenic mice. Here, we describe all steps involved from DNA purification to the set up of a mouse colony including vasectomy, injection of the DNA into a donor zygote, transfer of injected zygotes into recipient foster mice, screening of offspring and establishment of transgenic mouse lines. We discuss the use of neuron-specific promoters to express proteins with a role in Alzheimer disease. Transgenic expression of a truncated form of the microtubule-associated protein tau (delta tau) is used as an example for the anticipated results. %Z FOR Codes: 110903 %0 Journal Article %~ PubMed %A Ille, Fabian %A Atanasoski, Suzana %A Falk, Sven %A Ittner, Lars M %A Märki, David %A Büchmann-Møller, Stine %A Wurdak, Heiko %A Suter, Ueli %A Taketo, Makoto M %A Sommer, Lukas %T Wnt/BMP signal integration regulates the balance between proliferation and differentiation of neuroepithelial cells in the dorsal spinal cord. %B Developmental Biology %D 2007 %C United States %I Academic Press %V 304 %N 1 %P 394-408 %@ 1095-564X %X Multiple signaling pathways regulate proliferation and differentiation of neural progenitor cells during early development of the central nervous system (CNS). In the spinal cord, dorsal signaling by bone morphogenic protein (BMP) acts primarily as a patterning signal, while canonical Wnt signaling promotes cell cycle progression in stem and progenitor cells. However, overexpression of Wnt factors or, as shown here, stabilization of the Wnt signaling component beta-catenin has a more prominent effect in the ventral than in the dorsal spinal cord, revealing local differences in signal interpretation. Intriguingly, Wnt signaling is associated with BMP signal activation in the dorsal spinal cord. This points to a spatially restricted interaction between these pathways. Indeed, BMP counteracts proliferation promoted by Wnt in spinal cord neuroepithelial cells. Conversely, Wnt antagonizes BMP-dependent neuronal differentiation. Thus, a mutually inhibitory crosstalk between Wnt and BMP signaling controls the balance between proliferation and differentiation. A model emerges in which dorsal Wnt/BMP signal integration links growth and patterning, thereby maintaining undifferentiated and slow-cycling neural progenitors that form the dorsal confines of the developing spinal cord. %Z FOR Codes: 60106 110902 %0 Journal Article %~ PubMed %A Schild, Andreas %A Schmidt, Karsten %A Lim, Yun-An %A Ke, Yazi %A Ittner, Lars M %A Hemmings, Brian A %A Götz, Jürgen %T Altered levels of PP2A regulatory B/PR55 isoforms indicate role in neuronal differentiation. %B International journal of developmental neuroscience %D 2006 %C United Kingdom %I Pergamon %V 24 %N 7 %P 437-443 %@ 0736-5748 %X The ubiquitously expressed serine/threonine-specific protein phosphatase 2A (PP2A) is prominent in brain where it serves a wide range of functions under both physiological and pathological conditions. PP2A holoenzymes are composed of a catalytic subunit and a tightly complexed scaffolding subunit. This core enzyme associates with regulatory subunits of the B/PR55, B''/PR56/PR61, B''''/PR72 and B''''''/PR93/PR110 families. We previously determined distribution and expression levels of the four members of the B/PR55 family in brain, as dysregulation of this subunit family has been specifically implicated in neurodegenerative disorders including Alzheimer''s disease. In the present study, we used cell lines widely used in neuroscience research to determine levels of the four PR55 isoforms by qRT-PCR under different experimental conditions. We show that PR55alpha mRNA levels are highest in both HEK293 cells and SH-SY5Y neuroblastoma cells whereas PR55beta levels are lowest. Stepwise neuronal differentiation of SH-SY5Y cells causes the selective upregulation of PR55beta, and to some extent PR55gamma and PR55delta, but not PR55alpha mRNAs. In agreement with the qRT-PCR analysis, neuronal differentiation does not alter PR55alpha protein levels, whereas interestingly, PR55beta and PR55gamma protein levels are reduced when compared to undifferentiated cells. Our data point at specific roles for distinct regulatory B/PR55 subunits of PP2A in neuron-like cells with PR55alpha being the major isoform. %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Schild, Andreas %A Ittner, Lars M %A Götz, Jürgen %T Altered phosphorylation of cytoskeletal proteins in mutant protein phosphatase 2A transgenic mice. %B Biochemical and biophysical research communications %D 2006 %C United States %I Academic Press %V 343 %N 4 %P 1171-1178 %@ 1090-2104 %X Protein phosphatase 2A (PP2A) is a family of heterotrimeric enzymes with diverse functions under physiologic and pathologic conditions such as Alzheimer''s disease. All PP2A holoenzymes have in common a catalytic subunit C and a structural scaffolding subunit A. These core subunits assemble with various regulatory B subunits to form heterotrimers with distinct functions in the cell. Substrate specificity of PP2A in vitro is determined by regulatory subunits with leucine 309 of the catalytic subunit C playing a crucial role in the recruitment of regulatory subunits into the complex. Here we expressed a mutant form of Calpha, L309A, in brain and Harderian (lacrimal) gland of transgenic mice. We found an altered recruitment of regulatory subunits into the complex, demonstrating a role for the carboxyterminal leucine of Calpha in regulating holoenzyme assembly in vivo. This was associated with an increased phosphorylation of tau in brain and an impaired dephosphorylation of vimentin demonstrating that both cytoskeletal proteins are in vivo substrates of distinct PP2A holoenzyme complexes. %Z FOR Codes: 110199 %0 Journal Article %~ PubMed %A Wurdak, Heiko %A Ittner, Lars M %A Sommer, Lukas %T DiGeorge syndrome and pharyngeal apparatus development. %B BioEssays %D 2006 %C United Kingdom %I John Wiley & Sons Ltd. %V 28 %N 11 %P 1078-1086 %@ 0265-9247 %X DiGeorge syndrome is the most frequent microdeletion syndrome in humans, and is characterized by cardiovascular, thymic and parathyroid, and craniofacial anomalies. The underlying cause is disturbed formation of the pharyngeal apparatus, a transient structure present during vertebrate development that gives rise to endocrine glands, craniofacial tissue, and the cardiac outflow tract. The pharyngeal apparatus is composed of derivatives of ectoderm, endoderm, mesoderm and the neural crest. Thus, complex interactions between cell types from different origins have to be orchestrated in the correct spatiotemporal manner to establish proper formation of the pharyngeal system. The analysis of engineered mouse mutants developing a phenotype resembling DiGeorge syndrome has revealed genes and signalling pathways crucial for this process. Intriguingly, these mouse models reveal that interference with either of two distinct phases of pharyngeal apparatus development can contribute to the aetiology of DiGeorge syndrome. %Z FOR Codes: 60103 %0 Book Section %A Goetz, Juergen %A David, Della %A Ittner, Lars %T Impact of beta-amyloid on the tau pathology in tau transgenic mouse and tissue culture models %B Abeta Peptide and Alzheimer's Disease: Celebrating a Century of Research %D 2006 %C United Kingdom %I Springer %V %N %P 198-215 %@ 9781852339616 %E Barrow, Colin J %E Small, David H %X %Z FOR Codes: 110999 %0 Journal Article %~ PubMed %A Schild, Andreas %A Isenmann, Stefan %A Tanimoto, Naoyuki %A Tonagel, Felix %A Seeliger, Mathias W %A Ittner, Lars M %A Kretz, Alexandra %A Ogris, Egon %A Götz, Jürgen %T Impaired development of the Harderian gland in mutant protein phosphatase 2A transgenic mice. %B Mechanisms of development %D 2006 %C Ireland %I Elsevier %V 123 %N 5 %P 362-371 %@ 0925-4773 %X Although Harderian glands are especially large in rodents, many features of this retroocular gland, including its development and function, are not well established. Protein phosphatase 2A (PP2A) is a family of heterotrimeric enzymes expressed in this gland. PP2A substrate specificity is determined by regulatory subunits with leucine 309 of the catalytic subunit playing a crucial role in the recruitment of regulatory subunits into the complex in vitro. Here we expressed an L309A mutant catalytic subunit in Harderian gland of transgenic mice. We found a delayed postnatal development and hypoplasia of the gland, causing enophthalmos. To determine why expression of the L309A mutant caused this phenotype, we determined the PP2A subunit composition. We found an altered subunit composition in the transgenic gland that was accompanied by pronounced changes of proteins regulating cell adhesion. Specifically, cadherin and beta-catenin were dramatically reduced and shifted to the cytosol. Furthermore, we found an inactivating phosphorylation of the cadherin-directed glycogen synthase kinase-3beta. In conclusion, the carboxy-terminal leucine L309 of the PP2A catalytic subunit determines PP2A heterotrimer composition in vivo. Moreover, our data demonstrate that PP2A subunit composition plays a crucial role in regulating cell adhesion and as a consequence in the development of the Harderian gland. %Z FOR Codes: 110199 %0 Journal Article %~ PubMed %A Kelm, Jens M %A Ittner, Lars M %A Born, Walter %A Djonov, Valentin %A Fussenegger, Martin %T Self-assembly of sensory neurons into ganglia-like microtissues. %B Journal of Biotechnology %D 2006 %C Netherlands %I Elsevier BV %V 121 %N 1 %P 86-101 %@ 0168-1656 %X Unraveling intra- and inter-cellular signaling networks managing cell-fate control, coordinating complex differentiation regulatory circuits and shaping tissues and organs in living systems remain major challenges in the post-genomic era. Resting on the laurels of past-century monolayer culture technologies, the cell culture community has only recently begun to appreciate the potential of three-dimensional mammalian cell culture systems to reveal the full scope of mechanisms orchestrating the tissue-like cell quorum in space and time. Capitalizing on gravity-enforced self-assembly of monodispersed primary embryonic mouse cells in hanging drops, we designed and characterized a three-dimensional cell culture model for ganglion-like structures. Within 24h, a mixture of mouse embryonic fibroblasts (MEF) and cells, derived from the dorsal root ganglion (DRG) (sensory neurons and Schwann cells) grown in hanging drops, assembled to coherent spherical microtissues characterized by a MEF feeder core and a peripheral layer of DRG-derived cells. In a time-dependent manner, sensory neurons formed a polar ganglion-like cap structure, which coordinated guided axonal outgrowth and innervation of the distal pole of the MEF feeder spheroid. Schwann cells, present in embryonic DRG isolates, tended to align along axonal structures and myelinate them in an in vivo-like manner. Whenever cultivation exceeded 10 days, DRG:MEF-based microtissues disintegrated due to an as yet unknown mechanism. Using a transgenic MEF feeder spheroid, engineered for gaseous acetaldehyde-inducible interferon-beta (ifn-beta) production by cotransduction of retro-/ lenti-viral particles, a short 6-h ifn-beta induction was sufficient to rescue the integrity of DRG:MEF spheroids and enable long-term cultivation of these microtissues. In hanging drops, such microtissues fused to higher-order macrotissue-like structures, which may pave the way for sophisticated bottom-up tissue engineering strategies. DRG:MEF-based artificial micro- and macrotissue design demonstrated accurate key morphological aspects of ganglions and exemplified the potential of self-assembled scaffold-free multicellular micro-/macrotissues to provide new insight into organogenesis. %Z FOR Codes: 100404 %0 Journal Article %~ PubMed %A Kelm, Jens M %A Djonov, Valentin %A Hoerstrup, Simon P %A Guenter, Christina I %A Ittner, Lars M %A Greve, Frauke %A Hierlemann, Andreas %A Sanchez-Bustamante, Carlota Diaz %A Perriard, Jean-Claude %A Ehler, Elisabeth %A Fussenegger, Martin %T Tissue-transplant fusion and vascularization of myocardial microtissues and macrotissues implanted into chicken embryos and rats. %B Tissue Engineering %D 2006 %C United States %I Mary Ann Liebert, Inc. Publishers %V 12 %N 9 %P 2541-2553 %@ 1076-3279 %X Cell-based therapies and tissue engineering initiatives are gathering clinical momentum for next-generation treatment of tissue deficiencies. By using gravity-enforced self-assembly of monodispersed primary cells, we have produced adult and neonatal rat cardiomyocyte-based myocardial microtissues that could optionally be vascularized following coating with human umbilical vein endothelial cells (HUVECs). Within myocardial microtissues, individual cardiomyocytes showed native-like cell shape and structure, and established electrochemical coupling via intercalated disks. This resulted in the coordinated beating of microtissues, which was recorded by means of a multi-electrode complementary metal-oxide-semiconductor microchip. Myocardial microtissues (microm3 scale), coated with HUVECs and cast in a custom-shaped agarose mold, assembled to coherent macrotissues (mm3 scale), characterized by an extensive capillary network with typical vessel ultrastructures. Following implantation into chicken embryos, myocardial microtissues recruited the embryo''s capillaries to functionally vascularize the rat-derived tissue implant. Similarly, transplantation of rat myocardial microtissues into the pericardium of adult rats resulted in time-dependent integration of myocardial microtissues and co-alignment of implanted and host cardiomyocytes within 7 days. Myocardial microtissues and custom-shaped macrotissues produced by cellular self-assembly exemplify the potential of artificial tissue implants for regenerative medicine. %Z FOR Codes: 100404