title: Lipopolysaccharide-induced podocyte injury is mediated by suppression of autophagy.
abstract: High-level autophagy has an important role in maintaining the stable state of podocytes. The present study explored the influence of lipopolysaccharide (LPS) on autophagic activity in podocytes and demonstrated its mechanistic involvement in LPS-induced injury. Conditionally immortalized podocytes were cultured in vitro and were treated with chloroquine (CQ), LPS, LPS+rapamycin or LPS+3‑methyladenine (3‑MA). The autophagic vesicles and endoplasmic reticulum were observed using transmission electron microscopy. The tandem mRFP‑GFP‑LC3 adenovirus was used to detect autophagosomes and autolysosomes. The expression levels of light chain 3‑II (LC3 II), beclin‑1, P62, CCAAT‑enhancer‑binding protein homologous protein (CHOP) and podocin were determined by western blot analysis. Autophagic vesicles were detected in podocytes under basic conditions. CQ was found to increase the protein levels of LC3 II in a time‑dependent manner (2, 4 or 6 h), confirming the high activity of autophagy in podocytes. Compared with the control group, LPS induced the expansion of the endoplasmic reticulum and high expression levels of CHOP, while decreasing the protein expression of podocin. Notably, podocytes treated with LPS showed decreases in LC3 II and beclin‑1 levels and autophagosome/autolysosome numbers, which was accompanied by high P62 levels. Furthermore, the autophagy enhancer rapamycin reversed the downregulation of LC3 II and podocin, and the upregulation of CHOP induced by LPS, while the autophagy inhibitor 3‑MA aggravated the effects of LPS. In conclusion, the present study demonstrated that LPS inhibited podocyte autophagy, which contributed to LPS-induced injury of podocytes.
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Xiaofan
authors.initials: X
authors.lastname: Tan
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Yuanhan
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Xinling
authors.initials: X
authors.lastname: Liang
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Chunping
authors.initials: C
authors.lastname: Yu
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Yuxiong
authors.initials: Y
authors.lastname: Lai
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Xingchen
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Ting
authors.initials: T
authors.lastname: Lin
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Ruizhao
authors.initials: R
authors.lastname: Li
authors.affiliation: Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects*; D015415:Biomarkers; D008070:Lipopolysaccharides / Q000009:adverse effects*; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D010588:Phagosomes / Q000378:metabolism; D050199:Podocytes / Q000378:metabolism* / Q000473:pathology* / Q000648:ultrastructure; D020123:Sirolimus / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D008070:Lipopolysaccharides; D020123:Sirolimus