Immune complexes suppressed autophagy in glomerular endothelial cells

Lupus nephritis is an immune-complexes mediated glomerulonephritis. Vascular lesions and endothelial cell injuries are common in lupus nephritis and important for renal damage. However, the precise mechanisms by which immune complexes lead to endothelial cell injuries are still unclear. Autophagy is a conserved metabolic process and shows protective roles in many cell types and diseases. In present study, we investigated whether immune complexes could affect autophagy and participate in endothelial dysfunctions. Heat-aggregated gamma globulin (HAGG) was used to substitute immune complexes. Glomerular endothelial cells (GECs) were incubated with HAGG and autophagy-related markers were evaluated. Results showed that HAGG suppressed autophagy in GECs, through Akt/mTOR-dependent pathway. The combination of HAGG and tumor necrosis factor-alpha suppressed autophagy in GECs and further decreased cell viabilities. The suppressed effects of HAGG on GECs autophagy and viability, especially under inflammatory microenvironment, may provide new views for explaining the mechanisms of renal impairments in lupus nephritis.