{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Stavrides P"],"funding":["NIA NIH HHS","CHDI Foundation","National Institutes of Health","NIH HHS"],"pagination":["RP104979"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC12092004"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["14"],"pubmed_abstract":["Huntington's disease (HD) is caused by the expansion of the polyglutamine stretch in huntingtin protein (HTT) resulting in hallmark aggresomes/inclusion bodies (IBs) composed of mutant huntingtin protein (mHTT) and its fragments. Stimulating autophagy to enhance mHTT clearance is considered a potential therapeutic strategy for HD. Our recent evaluation of the autophagic-lysosomal pathway (ALP) in human HD brain reveals upregulated lysosomal biogenesis and relatively normal autophagy flux in early Vonsattel grade brains, but impaired autolysosome clearance in late grade brains, suggesting that autophagy stimulation could have therapeutic benefits as an early clinical intervention. Here, we tested this hypothesis by crossing the Q175 HD knock-in model with our autophagy reporter mouse TRGL (<b>T</b>hy-1-<b>R</b>FP-<b>G</b>FP-<b>L</b>C3) to investigate <i>in vivo</i> neuronal ALP dynamics. In the Q175 and/or TRGL/Q175 mice, mHTT was detected in autophagic vacuoles and also exhibited a high level of colocalization with autophagy receptors p62/SQSTM1 and ubiquitin in the IBs. Compared to the robust lysosomal pathology in late-stage human HD striatum, ALP alterations in Q175 models are also late-onset but milder, that included a lowered phospho-p70S6K level, lysosome depletion, and autolysosome elevation including more poorly acidified autolysosomes and larger-sized lipofuscin granules, reflecting impaired autophagic flux. Administration of a mTOR inhibitor to 6-mo-old TRGL/Q175 normalized lysosome number, ameliorated aggresome pathology while reducing mHTT-, p62-, and ubiquitin-immunoreactivities, suggesting the beneficial potential of autophagy modulation at early stages of disease progression."],"journal":["eLife"],"pubmed_title":["mTOR inhibition in Q175 Huntington's disease model mice facilitates neuronal autophagy and mutant huntingtin clearance."],"pmcid":["PMC12092004"],"funding_grant_id":["P01 AG017617"],"pubmed_authors":["Marchionini DM","Yang DS","Peddy J","Huo C","Goulbourne CN","Stavrides P","Rao M","Nixon RA","Khetarpal V"],"additional_accession":[]},"is_claimable":false,"name":"mTOR inhibition in Q175 Huntington's disease model mice facilitates neuronal autophagy and mutant huntingtin clearance.","description":"Huntington's disease (HD) is caused by the expansion of the polyglutamine stretch in huntingtin protein (HTT) resulting in hallmark aggresomes/inclusion bodies (IBs) composed of mutant huntingtin protein (mHTT) and its fragments. Stimulating autophagy to enhance mHTT clearance is considered a potential therapeutic strategy for HD. Our recent evaluation of the autophagic-lysosomal pathway (ALP) in human HD brain reveals upregulated lysosomal biogenesis and relatively normal autophagy flux in early Vonsattel grade brains, but impaired autolysosome clearance in late grade brains, suggesting that autophagy stimulation could have therapeutic benefits as an early clinical intervention. Here, we tested this hypothesis by crossing the Q175 HD knock-in model with our autophagy reporter mouse TRGL (<b>T</b>hy-1-<b>R</b>FP-<b>G</b>FP-<b>L</b>C3) to investigate <i>in vivo</i> neuronal ALP dynamics. In the Q175 and/or TRGL/Q175 mice, mHTT was detected in autophagic vacuoles and also exhibited a high level of colocalization with autophagy receptors p62/SQSTM1 and ubiquitin in the IBs. Compared to the robust lysosomal pathology in late-stage human HD striatum, ALP alterations in Q175 models are also late-onset but milder, that included a lowered phospho-p70S6K level, lysosome depletion, and autolysosome elevation including more poorly acidified autolysosomes and larger-sized lipofuscin granules, reflecting impaired autophagic flux. Administration of a mTOR inhibitor to 6-mo-old TRGL/Q175 normalized lysosome number, ameliorated aggresome pathology while reducing mHTT-, p62-, and ubiquitin-immunoreactivities, suggesting the beneficial potential of autophagy modulation at early stages of disease progression.","dates":{"release":"2025-01-01T00:00:00Z","publication":"2025 May","modification":"2026-06-01T14:54:52.728Z","creation":"2026-04-08T13:28:57.874Z"},"accession":"S-EPMC12092004","cross_references":{"pubmed":["40392702"],"doi":["10.7554/eLife.104979"]}}