The protective effect of hydroxytyrosol on contrast-induced nephropathy and endoplasmic reticulum stress

Objective To investigate the expression of glucose-regulated protein 78(GRP78) and cysteine aspartic acid protease 12(Caspase-12) and evaluate the endoplasmic reticulum stress (ERS) in rats with contrast-induced nephropathy (CIN), and observe the protective effects of hydroxytyrosol on CIN rats. Methods Eighty-four Wistar rats, (220±20) g, were randomly divided into control group, CIN group, hydroxytyrosol treated group (group C+H). At 12th, 24th, 48th, 72th day after the rats model were established, BUN and Scr were detected. ELISA were used to detect the expression of methane dicarboxylic aldehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). HE staining were used to evaluate the pathological change of kidney. TUNEL were used to detect the apoptosis of tubular cells. Real-time PCR were used to detect the expression of GRP78 mRNA and Caspase-12 mRNA in tubular cells. Immunohistochemistry and Western blotting were used to detect the expression of GRP78 and Caspase-12 protein in tubular cells. Results BUN, Scr, the mRNA and protein expression of GRP78, Caspase-12 in hydroxytyrosol treated group were higher than that in control group(P<0.05), but were significantly lower than that in CIN group (P<0.05). Pathological changes and the apoptosis of tubular cells in CIN group were more serious than that in hydroxytyrosol treated group (P<0.05). Conclusions Endoplasmic reticulum stress may be associated with contrast-induced nephropathy. Hydroxytyrosol can protect kidney from contrast medium via reducing the endoplasmic reticulum stress. Key words: Contrast media; Endoplasmic reticulum stress; Caspase 12; Glucose-regulated protein 78; Hydroxytyrosol