Aspirin intervenes in hyperlipidemia kidney damage by blocking endoplasmic reticulum stress in podocytes / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the effects and underlying mechanisms of aspirin on endoplasmic reticulum stress in podocytes induced by hyperlipemia.Methods:Cultured podocytes were divided into four groups control group, aspirin (100 μg/ml) group, oxidized low density lipoprotein (ox-LDL, 100 μg/ml) group, aspirin+ox-LDL group. The expression of protein kinase R-1ike endoplasmic reticulum kinase (PERK), eukaryotic translation initiation factor 2α (eIF2α), activating transcription factor-4 (ATF4) and CAAT/enhancer binding protein homologous protein (CHOP) at 6 h, 12 h, 24 h, 48 h were evaluated by real-time PCR. The related proteins of p-PERK and p-eIF2α at 24 h and ATF4 at 12 h were evaluated by Western blotting, respectively.Results:The expressions of PERK, eIF2α peaked at 24 h, while ATF4 and CHOP peaked at 12 h in ox-LDL group and aspirin+ox-LDL group. Compared with control group, the expressions of PERK, eIF2α, ATF4 and CHOP were significantly higher in ox-LDL group at each times (all P<0.05). Compared with ox-LDL group, the expressions of the above indicators were significantly lower in aspirin+ox-LDL group at each times (all P<0.05). At 24 h, compared with control group, the expressions of p-PERK and p-eIF2α were significantly higher in ox-LDL group (both P<0.05). Compared with ox-LDL group, the expressions of p-PERK and p-eIF2α were significantly lower in aspirin+ox-LDL group (both P<0.05). At 12 h, the expression of ATF4 protein in each group was similar to that of mRNA. There were no significant difference in the expressions of all indicators between aspirin group and control group. Conclusions:Hyperlipidemia may cause endoplasmic reticulum stress in podocytes by inducing phosphorylation of PERK and eIF2α, activating ATF4 transcription and inducing high expression of CHOP. Aspirin may partially block the PERK pathway, which may have protective effects for podocytes.