The correlation between oxidized low density lipoprotein receptor CD36 and renal tubular injury in diabetic rats

Abstract

Objective To observe the expressions of oxidized low density lipoprotein(OxLDL)receptor CD36 in kidney tissue of diabetic rats and in tubular cells incubated with OxLDL, and to explore the association of CD36 with the tubular injury and renal fibrosis in the process of diabetic nephropathy. Methods Diabetic rat model with hyperlipidemia was established by feeding with high sugar and fat diet and injection of low dose streptozotocin intraperitoneally. The expression of CD36 in kidney tissues was analyzed immunohistochemically. Meanwhile, the tubular sclerosis and fibrosis injury index were estimated and calculated. NRK-52E cells were stimulated with 50 mg/L OxLDL for 5, 10, 24, and 48 h, or 100 and 150 mg/L OxLDLs for 2 and 3 days. The protein expression of CD36 was detected by Western blot. Results The expression of CD36 in the renal tubulointerstitium of diabetic rats was increased comparing to that in control rats, and was localized mainly at tubular region. The renal tubular damage index(STI)of diabetes group was higher than that in control group(5.54±1.5 vs 0.65±0.15, P<0.05). OxLDL stimulated CD36 expression in NRK-52E cells in a dose- and time-dependent manner. Conclusion The expression of CD36 was increased in renal tubular of diabetic rats, in consistent with STI. OxLDL increased CD36 expression in NRK-52E cells. These results suggest that the expression of CD36 is associated with renal tubular damages in experimental rat diabetes. (Chin J Endocrinol Metab, 2016, 32: 602-606) Key words: Diabetic nephropathy; Renal tubule; Oxidized low density lipoprotein; CD36