RRC ID 54516
Author Peng X, Wang Y, Li H, Fan J, Shen J, Yu X, Zhou Y, Mao H.
Title ATG5-mediated autophagy suppresses NF-κB signaling to limit epithelial inflammatory response to kidney injury.
Journal Cell Death Dis
Abstract G2/M-arrested proximal tubular epithelial cells (TECs) after renal injury are linked to increased cytokines production. ATG5-mediated autophagy in proximal TECs has recently been shown to protect against G2/M cell cycle arrest and renal fibrosis. However, the impacts of autophagy in regulating inflammatorily response mounted by injured TECs remains largely unknown. In the present study, we investigated whether ATG5 acts as an innate immune suppressor in proximal TECs during kidney injury. Using the unilateral ureteric obstruction model in proximal tubule-specific autophagy-deficient mice, we demonstrated that ablation of epithelial ATG5 genes markedly impaired autophagy, resulting in enhanced nuclear factor κB (NF-κB) activation, macrophage and lymphocyte infiltration, and proinflammatory cytokines production in obstructed kidneys, as compared with wild-type mice. Following stimulation with angiotensin II (Ang II), siRNA silencing of ATG5 in cultured HK-2 cells or ATG5-deficient primary proximal TECs produced more cytokines, including IL-1β, IL-6, and TNF-α than did their control cells. Overexpressed ATG5, but not the autophagy-incompetent ATG5 mutant K130R in HK-2 cells, rendered resistant to Ang II-induced inflammatory response. Immunofluorescence assay indicated that ATG5 and p65 colocalized in the nucleus and cytoplasm, and their interaction was verified in immunoprecipitation assay from HEK-293T cell extracts. Genetic downregulation of endogenous ATG5 increased Ang II-induced phosphorylation and nuclear translocation of p65 and transcriptional activity of NF-κB, whereas the overexpressed ATG5, rather than ATG5 mutant K130R, hampered activation of NF-κB signaling, suggest an autophagy-dependent anti-inflammatory effect of ATG5. Further, pharmacological manipulation of autophagy yielded similar results both in vivo and in vitro. Additionally, JSH-23, a specific inhibitor of NF-κB nuclear translocation, rescued Ang II-driven IL-1β production in ATG5 siRNA-treated cells and decreased the proportion of cells in G2/M phase. In conclusion, ATG5-mediated autophagy in tubules targets NF-κB signaling to protect against renal inflammation.
Volume 10(4)
Pages 253
Published 2019-3-15
DOI 10.1038/s41419-019-1483-7
PII 10.1038/s41419-019-1483-7
PMID 30874544
PMC PMC6420665
MeSH Angiotensin II Animals Autophagy* / drug effects Autophagy* / genetics Autophagy* / immunology Autophagy-Related Protein 5 / genetics Autophagy-Related Protein 5 / metabolism* Cells, Cultured Cytokines / metabolism Disease Models, Animal Fibrosis G2 Phase Cell Cycle Checkpoints / drug effects G2 Phase Cell Cycle Checkpoints / genetics HEK293 Cells Humans Inflammation / genetics Inflammation / immunology Inflammation / metabolism Kidney / pathology* Kidney Tubules, Proximal / cytology Kidney Tubules, Proximal / metabolism* Male Mice Mice, Inbred C57BL Mice, Knockout NF-kappa B / antagonists & inhibitors NF-kappa B / genetics NF-kappa B / metabolism* Signal Transduction / genetics Ureteral Obstruction / genetics Ureteral Obstruction / immunology Ureteral Obstruction / metabolism
IF 5.959
Times Cited 9
Mice RBRC02975