02835nas a2200241   4500008004100000022001400041245008600055210006900141260006900210300001200279490000600291520205200297653001002349653001402359653002202373653001002395653000802405100001802413700001702431700001902448700001802467856010802485       2012                        eng d  a1547-628600aRegulation of BACE1 by miR-29a/b in a cellular model of spinocerebellar ataxia 170 aRegulation of BACE1 by miR29ab in a cellular model of spinocereb  a1806 RIO GRANDE ST, AUSTIN, TX 78702 USAbLANDES BIOSCIENCEcJUN  a891-8990 v93 a<p>Polyglutamine diseases are a class of neurodegenerative disorders characterized by expansion of polyglutamine repeats, protein aggregation and neuronal cell death in specific regions of the brain. The expansion of a polyglutamine repeat in the TATA binding protein (TBP) causes a neurodegenerative disease, Spinocerebellar Ataxia 17 (SC A17). This disease is characterized by intranuclear protein aggregates and selective loss of cerebellar neurons, including Purkinje cells. MicroRNAs are small, endogenous, regulatory non-coding RNA molecules that bind to mRNAs with partial complementarity and interfere in their expression. Here, we used a cellular model of SC A17 where we expressed TBP with 16 (normal) or 59 (pathogenic) polyglutamines and found differential expression of several microRNAs. Specifically, we found two microRNAs, miR-29a/b, were downregulated. With miR-29a/b downregulation, we found an increased expression of targets of miR-29a/b-beta-site amyloid precursor protein cleaving enzyme 1 (BACE 1), p53 upregulated modulator of apoptosis (PUMA) and BAK, increased cytochrome c release and apoptosis. Restoration of miR-29a/b in the pathogenic polyglutamine background reduced the BACE 1 expression. While, antagomiRs against miR-29a/b resulted in an increase in BACE 1 levels and neuronal apoptosis. In spite of the elevation of BACE 1 in Alzhemiers disease, its role in neuronal cell death has not been established. Here, we show that increased BACE 1 expression is not sufficient to cause apoptosis. However restoring level of BACE 1 to normal in polyglutamine cells partially reduced neuronal apoptosis. We show a role for the miR-29a/b-BACE 1 regulatory interaction in SC A17, suggesting that this microRNA could be part of a common molecular mechanism leading to neuronal cell death in multiple neurodegenerative disorders. The identification of a common mechanism of microRNA mediated neurodegeneration not only improves our understanding of the process, but also provides promising and novel therapeutic targets.</p>10aBACE110amiR-29a/b10aneurodegeneration10aSCA1710aTBP1 aRoshan, Reema1 aGhosh, Tanay1 aGadgil, Mugdha1 aPillai, Beena  uhttps://library.ncl.res.in/content/regulation-bace1-mir-29ab-cellular-model-spinocerebellar-ataxia-17-002973nas a2200277   4500008004100000022001400041245012000055210006900175260000800244300002100252490000700273520204300280653002102323653002202344653001502366653001402381653001402395653002202409653000902431653001402440653002902454100001602483700002802499700003602527856013202563       2020                        eng d  a1759-091400aMelatonin reduces GSK3 beta-mediated tau phosphorylation, enhances Nrf2 nuclear translocation and anti-inflammation0 aMelatonin reduces GSK3 betamediated tau phosphorylation enhances  cDEC  a17590914209812040 v123 a<p>Alzheimer's disease is a neuropathological condition with abnormal accumulation of extracellular Amyloid-beta plaques and intracellular neurofibrillary tangles of Microtubule-associated protein Tau (Tau) in the brain. In pathological conditions, Tau undergoes post-translational modifications such as hyperphosphorylation by the activity of cellular kinases, which eventually leads to protein aggregation in neurons. Melatonin is a neuro-hormone that is mainly secreted from the pineal gland and functions to modulate the cellular kinases. In our study, we have checked the neuroprotective function of Melatonin by MTT and LDH assay, where Melatonin inhibited the Tau aggregates-mediated cytotoxicity and membrane leakage in Neuro2A cells. The potency of Melatonin has also been studied for the quenching of intracellular reactive oxygen species level by DCFDA assay and caspase 3 activity. Melatonin was shown to reduce the GSK3 beta mRNA and subsequent protein level as well as the phospho-Tau level (pThr181 and pThr212-pSer214) in okadaic acid-induced Neuro2A cells, as observed by western blot and immunofluorescence assay. Further, Melatonin has increased the cellular Nrf2 level and its nuclear translocation as an oxidative stress response in Tauopathy. The Melatonin was found to induce pro- and anti-inflammatory cytokines levels in N9 microglia. The mRNA level of cellular kinases such as as-GSK3 beta, MAPK were also studied by qRT-PCR assay in Tau-exposed N9 and Neuro2A cells. The immunomodulatory effect of Melatonin was evident as it induced IL-10 and TGF-beta cytokine levels and activated MAP3K level in Tau-exposed microglia and neurons, respectively. Melatonin also downregulated the mRNA level of pro-inflammatory markers, IL-1 beta and Cyclooxygenase-2 in N9 microglia. Together, these findings suggest that Melatonin remediated the cytokine profile of Tau-exposed microglia, reduced Tau hyperphosphorylation by downregulating GSK3 beta level, and alleviated oxidative stress via Nrf2 nuclear translocation.</p>
10aAlzheimer&\#821710aAnti-inflammatory10aGSK3&\#94610amelatonin10amicroglia10aneurodegeneration10aNrf210as disease10aTau hyperphosphorylation1 aDas, Rashmi1 aBalmik, Abhishek, Ankur1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/melatonin-reduces-gsk3-beta-mediated-tau-phosphorylation-enhances-nrf2-nuclear-translocation03043nas a2200253   4500008004100000245008900041210006900130260000900199300000700208490000700215520224100222653001002463653001502473653002402488653001402512653001402526653002202540653001802562653001402580100001602594700002802610700003602638856011502674       2020                        eng d00aPhagocytosis of full-length Tau oligomers by Actin-remodeling of activated microglia0 aPhagocytosis of fulllength Tau oligomers by Actinremodeling of a  cJAN   a100 v173 a<p>Background Alzheimer's disease is associated with the accumulation of intracellular Tau tangles within neurons and extracellular amyloid-beta plaques in the brain parenchyma, which altogether results in synaptic loss and neurodegeneration. Extracellular concentrations of oligomers and aggregated proteins initiate microglial activation and convert their state of synaptic surveillance into a destructive inflammatory state. Although Tau oligomers have fleeting nature, they were shown to mediate neurotoxicity and microglial pro-inflammation. Due to the instability of oligomers, in vitro experiments become challenging, and hence, the stability of the full-length Tau oligomers is a major concern. Methods In this study, we have prepared and stabilized hTau40(WT) oligomers, which were purified by size-exclusion chromatography. The formation of the oligomers was confirmed by western blot, thioflavin-S, 8-anilinonaphthaalene-1-sulfonic acid fluorescence, and circular dichroism spectroscopy, which determine the intermolecular cross-beta sheet structure and hydrophobicity. The efficiency of N9 microglial cells to phagocytose hTau40(WT) oligomer and subsequent microglial activation was studied by immunofluorescence microscopy with apotome. The one-way ANOVA was performed for the statistical analysis of fluorometric assay and microscopic analysis. Results Full-length Tau oligomers were detected in heterogeneous globular structures ranging from 5 to 50 nm as observed by high-resolution transmission electron microscopy, which was further characterized by oligomer-specific A11 antibody. Immunocytochemistry studies for oligomer treatment were evidenced with A11(+) Iba1(high) microglia, suggesting that the phagocytosis of extracellular Tau oligomers leads to microglial activation. Also, the microglia were observed with remodeled filopodia-like actin structures upon the exposure of oligomers and aggregated Tau. Conclusion The peri-membrane polymerization of actin filament and co-localization of Iba1 relate to the microglial movements for phagocytosis. Here, these findings suggest that microglia modified actin cytoskeleton for phagocytosis and rapid clearance of Tau oligomers in Alzheimer's disease condition.</p>
10aActin10aactivation10aAlzheimer's disease10amicroglia10amigration10aneurodegeneration10aTau Oligomers10aTauopathy1 aDas, Rashmi1 aBalmik, Abhishek, Ankur1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/phagocytosis-full-length-tau-oligomers-actin-remodeling-activated-microglia02652nas a2200277   4500008004100000245011100041210006900152260000900221300000700230490000700237520177100244653001002015653001702025653001002042653001602052653002202068653002002090653001202110653001402122653000802136653001602144100002802160700002902188700003602217856012102253       2021                        eng d00aExtracellular HDAC6 ZnF UBP domain modulates the actin network and post-translational modifications of Tau0 aExtracellular HDAC6 ZnF UBP domain modulates the actin network a  cMAY   a490 v193 a<p>Background: Microtubule-associated protein Tau undergoes aggregation in Alzheimer`s disease (AD) and a group of other related diseases collectively known as Tauopathies. In AD, Tau forms aggregates, which are deposited intracellularly as neurofibrillary tangles. Histone deacetylase-6 (HDAC6) plays an important role in aggresome formation, where it recruits polyubiquitinated aggregates to the motor protein dynein. Methods: Here, we have studied the effects of HDAC6 ZnF UBP on Tau phosphorylation, ApoE localization, GSK-3 beta regulation and cytoskeletal organization in neuronal cells by immunocytochemical analysis. This analysis reveals that the cell exposure to the UBP-type zinc finger domain of HDAC6 (HDAC6 ZnF UBP) can modulate Tau phosphorylation and actin cytoskeleton organization. Results: HDAC6 ZnF UBP treatment to cells did not affect their viability and resulted in enhanced neurite extension and formation of structures similar to podosomes, lamellipodia and podonuts suggesting the role of this domain in actin re-organization. Also, HDAC6 ZnF UBP treatment caused increase in nuclear localization of ApoE and tubulin localization in microtubule organizing centre (MTOC). Therefore, our studies suggest the regulatory role of this domain in different aspects of neurodegenerative diseases. Upon HDAC6 ZnF UBP treatment, inactive phosphorylated form of GSK-3 beta increases without any change in total GSK-3 beta level. Conclusions: HDAC6 ZnF UBP was found to be involved in cytoskeletal re-organization by modulating actin dynamics and tubulin localization. Overall, our study suggests that ZnF domain of HDAC6 performs various regulatory functions apart from its classical function in aggresome formation in protein misfolding diseases.</p>10aActin10aCytoskeleton10aHDAC610aMicrotubule10aneurodegeneration10aPhosphorylation10aPodonut10aPodosomes10aTau10aTauopathies1 aBalmik, Abhishek, Ankur1 aSonawane, Shweta, Kishor1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/extracellular-hdac6-znf-ubp-domain-modulates-actin-network-and-post-translational