Sublytic C5b-9 induces protective autophagy in cultured podocytes / 中国病理生理杂志

ABSTRACT

AIM:In podocytes , autophagy occurs at a high basal level and dysregulated autophagy is associa -ted with a variety of podocytopathies .This paper is to investigate the role of autophagy in sublytic C 5b-9-induced podocyte injury.METHODS: Sublytic complement C5b-9 stimulation was used as an in vitro model.Autophagosomes were con-firmed using monodansylcadaverine (MDC) staining.Immunoblotting was used to measure the change of autophagy-related markers.Cellular morphological changes were observed by Wright-Giemsa staining.Immunofluorescence staining and con-focal microscopy were used to detect the expression and distribution of nephrin .The cell viability was assessed by methylth-iazol tetrazolium (MTT) assay.The cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/PI staining.RE-SULTSFor ensuring sublytic complement injury , the maximal amounts of anti-podocyte antiserum and 160 ×-diluted nor-mal human serum were used without inducing cell lysis (defined as >5%LDH release).Sublytic C5b-9 promoted autoph-agy of podocytes in vitro.The proautophagic effect of sublytic C 5b-9 manifested in the form of accumulated MDC-labeled vesicles and enhanced the expression of LC 3-Ⅱ.Autophagy inhibitor 3-methyladenosine (3-MA) promoted sublytic C5b-9-induced podocyte morphological abnormalities .Compared with the sublytic C5b-9-injured podocytes, 3-MA exposure further decreased the expression of nephrin .3-MA enhanced sublytic C5b-9-induced podocyte apoptosis .CONCLUSION: Sub-lytic C5b-9 attack induces autophagy , which may play a protective role against complement-mediated podocyte injury .