title: Trehalose, an mTOR independent autophagy inducer, alleviates human podocyte injury after puromycin aminonucleoside treatment.
abstract: Glomerular diseases are commonly characterized by podocyte injury including apoptosis, actin cytoskeleton rearrangement and detachment. However, the strategies for preventing podocyte damage remain insufficient. Recently autophagy has been regarded as a vital cytoprotective mechanism for keeping podocyte homeostasis. Thus, it is reasonable to utilize this mechanism to attenuate podocyte injury. Trehalose, a natural disaccharide, is an mTOR independent autophagy inducer. It is unclear whether trehalose alleviates podocyte injury. Therefore, we investigated the efficacy of trehalose in puromycin aminonucleoside (PAN)-treated podocytes which mimic cell damage in minimal change nephrotic syndrome in vitro. Human conditional immortalized podocytes were treated with trehalose with or without PAN. Autophagy was investigated by immunofluorescence staining for LC3 puncta and Western blotting for LC3, Atg5, p-AMPK, p-mTOR and its substrates. Podocyte apoptosis and necrosis were evaluated by flow cytometry and by measuring lactate dehydrogenase activity respectively. We also performed migration assay to examine podocyte recovery. It was shown that trehalose induced podocyte autophagy in an mTOR independent manner and without reactive oxygen species involvement. Podocyte apoptosis significantly decreased after trehalose treatment, while the inhibition of trehalose-induced autophagy abolished its protective effect. Additionally, the disrupted actin cytoskeleton of podocytes was partially reversed by trehalose, accompanying with less lamellipodias and diminished motility. These results suggested that trehalose induced autophagy in human podocytes and showed cytoprotective effects in PAN-treated podocytes.
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hunghom, Hong Kong, China; Department of Nephrology and Rheumatology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Kang
authors.affiliation: Academic Renal Unit, University of Bristol, Southmead Hospital, Bristol, United Kingdom.
authors.forename: Moin Ahson
authors.initials: MA
authors.lastname: Saleem
authors.affiliation: Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong, China.
authors.forename: Kwok Wah
authors.initials: KW
authors.lastname: Chan
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hunghom, Hong Kong, China.
authors.forename: Benjamin Yat-Ming
authors.initials: BY
authors.lastname: Yung
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hunghom, Hong Kong, China.
authors.forename: Helen Ka-Wai
authors.initials: HK
authors.lastname: Law
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D000071187:Autophagy-Related Protein 5; D015153:Blotting, Western; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D006801:Humans; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000276:immunology / Q000378:metabolism; D009402:Nephrosis, Lipoid / Q000378:metabolism / Q000473:pathology; D050199:Podocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011692:Puromycin Aminonucleoside / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D014199:Trehalose / Q000494:pharmacology*
chemical_list: C502778:ATG5 protein, human; D000903:Antibiotics, Antineoplastic; D000071187:Autophagy-Related Protein 5; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D017382:Reactive Oxygen Species; D011692:Puromycin Aminonucleoside; D014199:Trehalose; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases