02270nas a2200217   4500008004100000022001400041245010100055210006900156260000800225300001200233490000700245520150100252653002201753653004401775653002301819653000801842653001601850100002901866700003601895856012101931       2018                        eng d  a0895-869600aPrion-like propagation of post-translationally modified tau in alzheimer's disease: a hypothesis0 aPrionlike propagation of posttranslationally modified tau in alz  cAUG  a480-4900 v653 a<p>The microtubule-associated protein Tau plays a key role in the neuropathology of Alzheimer's disease by forming intracellular neurofibrillary tangles. Tau in the normal physiological condition helps stabilize microtubules and transport. Tau aggregates due to various gene mutations, intracellular insults and abnormal post-translational modifications, phosphorylation being the most important one. Other modifications which alter the function of Tau protein are glycation, nitration, acetylation, methylation, oxidation, etc. In addition to forming intracellular aggregates, Tau pathology might spread in a prion-like manner as revealed by several in vitro and in vivo studies. The possible mechanism of Tau spread can be via bulk endocytosis of misfolded Tau species. The recent studies elucidating this mechanism have mainly focussed on the aggregation and spread of repeat domain of Tau in the cell culture models. Further studies are needed to elucidate the prion-like propagation property of full-length Tau and its aggregates in a more intense manner in vitro as well as in vivo conditions. Varied post-translational modifications can have discrete effects on aggregation propensity of Tau as well as its propagation. Here, we review the prion-like properties of Tau and hypothesize the role of glycation in prion-like properties of Tau. This post-translationally modified Tau might have an enhanced propagation property due to differential properties conferred by the modifications.</p>10aAlzheimer disease10aPost-translational modifications of tau10aPropagation of tau10aTau10aTauopathies1 aSonawane, Shweta, Kishor1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/prion-propagation-post-translationally-modified-tau-alzheimers-disease-hypothesis02655nas a2200181   4500008004100000022001400041245008000055210006900135260000900204300001600213490000600229520200500235100001802240700002802258700004002286700003602326856011102362       2019                        eng d  a2470-134300aPhotoexcited toluidine blue inhibits tau aggregation in Alzheimer's disease0 aPhotoexcited toluidine blue inhibits tau aggregation in Alzheime  cNOV   a18793-188020 v43 a<p>The aggregates of microtubule-associated protein Tau are considered as a major hallmark of Alzheimer's disease. Tau aggregates accumulate intracellularly leading to neuronal toxicity. Numerous approaches have been targeted against Tau protein aggregation, which include application of synthetic and natural compounds. Toluidine blue is a basic dye of phenothiazine family, which on irradiation with a 630 nm light gets converted into a photoexcited form, leading to generation of singlet oxygen species. Methylene blue is the parent compound of toluidine blue, which has been reported to be potent against tauopathy. In the present work, we studied the potency of toluidine blue and photoexcited toluidine blue against Tau aggregation. Biochemical and biophysical analyses using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, ThS fluorescence, circular dichroism spectroscopy, and electron microscopy suggested that toluidine blue inhibited the aggregation of Tau in vitro. The photoexcited toluidine blue potentially dissolved the matured Tau fibrils, which indicated the disaggregation property of toluidine blue. The cell biology studies including the cytotoxicity assay and reactive oxygen species (ROS) production assay suggested toluidine blue to be a biocompatible dye as it reduced ROS levels and cell death. The photoexcited toluidine blue modulates the cytoskeleton network in cells, which was supported by immunofluorescence studies of neuronal cells. The studies in a UAS Tau E14 transgenic Drosophila model suggested that photoexcited toluidine blue was potent to restore the survival and memory deficits of Drosophila. The overall finding of our studies suggested toluidine blue to be a potent molecule in rescuing the Tau-mediated pathology by inhibiting its aggregation, reducing the cell death, and modulating the tubulin levels and behavioral characteristics of Drosophila. Thus, toluidine blue can be addressed as a potent molecule against Alzheimer's disease.</p>
1 aDubey, Tushar1 aNalini, Gorantla, Vijay1 aChandrashekara, Kagepura, Thammaiah1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/photoexcited-toluidine-blue-inhibits-tau-aggregation-alzheimers-disease01813nas a2200157   4500008004100000245008600041210006900127260000900196300001600205490000600221520122900227100002901456700001701485700003601502856011701538       2019                        eng d00aProtein-capped metal nanoparticles inhibit tau aggregation in alzheimer's disease0 aProteincapped metal nanoparticles inhibit tau aggregation in alz  cJULY  a12833-128400 v43 a<p>The Alzheimer's disease (AD) therapeutic research is yielding a large number of potent molecules. The nanoparticle-based therapeutics against the protein aggregation in AD is also taking a lead especially with amyloid-beta as a primary target. In this work, we have screened for the first time protein-capped (PC) metal nanoparticles for their potency in inhibiting Tau aggregation in vitro. We present a novel function of PC-Fe3O4 and PC-CdS nanoparticles as potent Tau aggregation inhibitors by fluorescence spectrometry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and electron microscopy. We demonstrate that the biologically synthesized PC-metal nanoparticles, especially iron oxide do not affect the viability of neuroblastoma cells. Moreover, PC-CdS nanoparticles show dual properties of inhibition and disaggregation of Tau. Thus, the nanoparticles can take a lead as potent Tau aggregation inhibitors and can be modified for specific drug delivery due to their very small size. The current work presents unprecedented strategy to design anti-Tau aggregation drugs, which provides interesting insights to understand the role of biological nanostructures in Alzheimer's disease.<br />
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1 aSonawane, Shweta, Kishor1 aAhmad, Absar1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/protein-capped-metal-nanoparticles-inhibit-tau-aggregation-alzheimers-disease02201nas a2200205   4500008004100000022001400041245006800055210006500123260000800188300001000196490000700206520153200213653003601745653002401781653001201805653001801817100002901835700003601864856009501900       2020                        eng d  a1387-287700aP301 L, an FTDP-17 mutant, exhibits enhanced glycation in vitro0 aP301 L an FTDP17 mutant exhibits enhanced glycation in vitro  cJAN  a61-710 v753 a<p>Background: Frontotemporal dementia and parkinsonism-linked to chromosome-17 are a group of diseases with tau mutations leading to primary tauopathies which include progressive supranuclear palsy, corticobas al syndrome, and frontotemporal lobar degeneration. Alzheimer's disease is a non-primary tauopathy, which displays tau neuropathology of excess tangle formation and accumulation. FTDP-17 mutations are responsible for early onset of AD, which can be attributed to compromised physiological functions due to the mutations. Tau is a microtubule-binding protein that secures the integrity of polymerized microtubules in neuronal cells. It malfunctions owing to various insults and stress conditions-like mutations and post-translational modifications. Objective: In this study, we modified the wild type and tau mutants by methyl glyoxal and thus studied whether glycation can enhance the aggregation of predisposed mutant tau. Methods: Tau glycation was studied by fluorescence assays, SDS-PAGE analysis, conformational evaluation, and transmission electron microscopy. Results: Our study suggests that FTDP-17 mutant P301 L leads to enhanced glycation-induced aggregation as well as advanced glycation end products formation. Glycation forms amorphous aggregates of tau and its mutants without altering its native conformation. Conclusion: The metabolic anomalies and genetic predisposition have found to accelerate tau-mediated neurodegeneration and prove detrimental for the early-onset of Alzheimer's disease.</p>
10aadvanced glycation end products10aAlzheimer's disease10aFTDP-1710atau glycation1 aSonawane, Shweta, Kishor1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/p301-l-ftdp-17-mutant-exhibits-enhanced-glycation-vitro03043nas 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-microglia02326nas a2200181   4500008004100000022001400041245011900055210006900174260000800243300001000251490000700261520162900268100001801897700002801915700004001943700003601983856012502019       2020                        eng d  a2045-232200aPhotodynamic exposure of Rose-Bengal inhibits Tau aggregation and modulates cytoskeletal network in neuronal cells0 aPhotodynamic exposure of RoseBengal inhibits Tau aggregation and  cJUL  a123800 v103 a<p>The intracellular Tau aggregates are known to be associated with Alzheimer's disease. The inhibition of Tau aggregation is an important strategy for screening of therapeutic molecules in Alzheimer's disease. Several classes of dyes possess a unique property of photo-excitation, which is applied as a therapeutic measure against numerous neurological dysfunctions. Rose Bengal is a Xanthene dye, which has been widely used as a photosensitizer in photodynamic therapy. The aim of this work was to study the protective role of Rose Bengal against Tau aggregation and cytoskeleton modulations. The aggregation inhibition and disaggregation potency of Rose Bengal and photo-excited Rose Bengal were observed by in-vitro fluorescence, circular dichroism, and electron microscopy. Rose Bengal and photo-excited Rose Bengal induce minimal cytotoxicity in neuronal cells. In our studies, we observed that Rose Bengal and photo-excited Rose Bengal modulate the cytoskeleton network of actin and tubulin. The immunofluorescence studies showed the increased filopodia structures after photo-excited Rose Bengal treatment. Furthermore, Rose Bengal treatment increases the connections between the cells. Rose Bengal and photo-excited Rose Bengal treatment-induced actin-rich podosome-like structures associated with cell membranes. The in-vivo studies on UAS E-14 Tau mutant Drosophila suggested that exposure to Rose Bengal and photo-excited Rose Bengal efficiency rescues the behavioural and memory deficit in flies. Thus, the overall results suggest that Rose Bengal could have a therapeutic potency against Tau aggregation.</p>
1 aDubey, Tushar1 aGorantla, Nalini, Vijay1 aChandrashekara, Kagepura, Thammaiah1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/photodynamic-exposure-rose-bengal-inhibits-tau-aggregation-and-modulates-cytoskeletal02005nas a2200133   4500008004100000245007900041210006900120260001300189300001200202520148000214100002701694700003601721856011401757       2020                        eng d00aProtein misfolding and aggregation of tau protein in alzheimer’s disease0 aProtein misfolding and aggregation of tau protein in alzheimer s  bSpringer  a139-1463 a<p><span style="color: rgb(51, 51, 51); font-family: Roboto, Arial, sans-serif; font-size: 14px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">Protein misfolding has interestingly been referred to as the ‘dark side’ of the protein world. The cytotoxicity of misfolded and unfolded polypeptides is due to an overwhelmed quality control system, mainly comprising molecular chaperones to assist in folding, the unfolded protein response (UPR) in the endoplasmic reticulum and the heat shock response (HSR) in the cytosol, which are aimed at clearing misfolded proteins and their early aggregates. When misfolded/unfolded polypeptides exceed the quality control measures of the chaperone–ubiquitin–proteasome clearing system, they form toxic pre-fibrillar aggregates which interact with the cell membrane, disrupting redox potential due to aggregate organization into non-specific membrane pores. In most cases, increases in intracellular free Ca²⁺ and consequent disruption of the redox potential are among the earliest biochemical alterations in exposed cells. An improved understanding of the mechanisms of protein misfolding and intermediate structures that lead from monomers to oligomers ready to aggregate could provide crucial impetus to therapeutic interventions such as upregulating molecular chaperone machinery, use of antibodies and high throughput screening of promising candidate molecules.</span></p>1 aChandrashekar, Madhura1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/protein-misfolding-and-aggregation-tau-protein-alzheimer%E2%80%99s-disease02570nas a2200217   4500008004100000245011000041210006900151260000800220300000700228490000700235520179900242653002102041653002402062653002402086653001702110653002202127653001902149100002602168700003602194856012202230       2021                        eng d00aPhosphoinositides signaling modulates microglial actin remodeling and phagocytosis in Alzheimer's disease0 aPhosphoinositides signaling modulates microglial actin remodelin  cFEB  a280 v193 a<p>Alzheimer's disease is one of the neurodegenerative diseases, characterized by the accumulation of abnormal protein deposits, which disrupts signal transduction in neurons and other glia cells. The pathological protein in neurodegenerative diseases, Tau and amyloid-P contribute to the disrupted microglial signaling pathways, actin cytoskeleton, and cellular receptor expression. The important secondary messenger lipids i.e., phosphatidylinositols are largely affected by protein deposits of amyloid-beta in Alzheimer's disease. Phosphatidylinositols are the product of different phosphatidylinositol kinases and the state of phosphorylation at D3, D4, and D5 positions of inositol ring. Phosphatidylinositol 3,4,5-triphosphate (PI 3, 4, 5-P3) involves in phagocytic cup formation, cell polarization, whereas Phosphatidylinositol 4,5-bisphosphate (PI 4, 5-P2)-mediates the process of phagosomes formation and further its fusion with early endosome.. The necessary activation of actin-binding proteins such as Rac, WAVE complex, and ARP2/3 complex for the actin polymerization in the process of phagocytosis, migration is regulated and maintained by PI 3, 4, 5-P3 and PI 4, 5-P2. The ratio and types of fatty acid intake can influence the intracellular secondary lipid messengers along with the cellular content of phaphatidylcholine and phosphatidylethanolamine. The Amyloid-beta deposits and extracellular Tau seeds disrupt phosphatidylinositides level and actin cytoskeletal network that hamper microglial-signaling pathways in AD. We hypothesize that being a lipid species intracellular levels of phosphatidylinositol would be regulated by dietary fatty acids. Further we are interested to understand phosphoinositide-based signaling cascades in phagocytosis and actin remodeling.</p>
10aactin remodeling10aAlzheimer's disease10aDietary fatty acids10aPhagocytosis10aPhosphoinositides10aPI3K signaling1 aDesale, Smita, Eknath1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/phosphoinositides-signaling-modulates-microglial-actin-remodeling-and-phagocytosis01857nas a2200241   4500008004100000022001400041245008900055210006900144260000800213300001200221490000700233520106600240653001001306653001901316653002801335653002601363653002501389653001401414653001201428100001801440700003601458856012101494       2021                        eng d  a1949-358400aPhotodynamic sensitizers modulate cytoskeleton structural dynamics in neuronal cells0 aPhotodynamic sensitizers modulate cytoskeleton structural dynami  cJUN  a232-2480 v783 a<p>The neuronal cytoskeleton plays a crucial role in maintaining cell integrity and functioning of neurons. Cytoskeleton deformities have been reported to be associated with neurodegenerative diseases thus; cytoskeleton can be targeted for therapeutic strategies. The therapeutic application of photosensitive molecule is termed as photodynamic therapy (PDT). PDT has been applied in the field of dermatology, cancer biology, and antimicrobial therapy. PDT induces several changes in cells, which include induction of apoptosis, DNA damage, and induction of inflammatory response. PDT has been also reported to modulate cytoskeleton such as actin dynamics. The in vitro studies suggested that PDT using dyes such as Toluidine Blue and Rose Bengal effectively modulated the actin cytoskeleton, neurite outgrowth, tubulin, and Tau aggregation. In this review, we focused on the effect of photosensitized molecules on various cytoskeleton proteins. We hypothesize that PDT could have potency against Alzheimer's disease and other neurodegenerative disorders.</p>
10aActin10aAlzheimer&apos10acytoskeleton modulation10aneuronal cytoskeleton10aphotodynamic therapy10as disease10aTubulin1 aDubey, Tushar1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/photodynamic-sensitizers-modulate-cytoskeleton-structural-dynamics-neuronal-cells01544nas a2200133   4500008004100000245009800041210006900139260000800208300000900216520100100225100001801226700003601244856013001280       2021                        eng d00aPhotodynamic treatment modulates various GTPase and cellular signalling pathways in Tauopathy0 aPhotodynamic treatment modulates various GTPase and cellular sig  cJUN  a1-133 aABSTRACTThe application of photo-excited dyes for treatment is known as photodynamic therapy (PDT). PDT is known to target GTPase proteins in cells, which are the key proteins of diverse signalling cascades which ultimately modulate cell proliferation and death. Cytoskeletal proteins play critical roles in maintaining cell integrity and cell division. Whereas, it was also observed that in neuronal cells PDT modulated actin and tubulin resulting in increased neurite growth and filopodia. Recent studies supported the role of PDT in dissolving the extracellular amyloid beta aggregates and intracellular Tau aggregates, which indicated the potential role of PDT in neurodegeneration. The advancement in the field of PDT led to its clinical approval in treatment of cancers, brain tumour, and dermatological acne. Although several question need to be answered for application of PDT in neuronal cells, but the primary studies gave a hint that it can emerge as potential therapy in neural cells.1 aDubey, Tushar1 aChinnathambi, Subashchandrabose  uhttps://library.ncl.res.in/content/photodynamic-treatment-modulates-various-gtpase-and-cellular-signalling-pathways-tauopathy