Abstract: Objective:To explore the influence of tanshinone ⅡA on the expressions of molecular chaperone Cosmc, advanced oxidation protein products (AOPP) in the kidney tissue of the allergic purpura nephritis mice and the levels of extracellular signal-regulated kinase/mitogen activated protein kinase (ERK/MAPK) signaling pathway proteins,and to clarify mechanism of tanshinone Ⅱ A in the treatment of allergic purpura nephritis. Methods:A total of 38 mice were divided into control group, model group (allergic purpura nephritis model) and tanshinone Ⅱ A group (allergic purpura nephritis model + tanshinone Ⅱ A treatment), with 12 in each group; the other 2 mice were used to verify the success of modeling. The urine red blood cell counts and urine protein levels of the mice in various groups were measured, and the pathomorphology of kidney tissue of the mice in various groups were observed by periodate schiff-reaction (PAS) staining. The AOPP protein levels in the kidney tissue of the mice were determined by enzyme linked immunosorbent assay (ELISA), and the ERK and phosphorylated ERK (p-ERk) protein expression levels were determined by Western blotting method. The expression levels of ERK, p-ERK and Cosmc mRNA in kidney tissue of the mice were determined by RT-PCR. Results:In control group, there was no hyperplasia of glomerular basement membrane and no glomerular sclerosis;in model group, the proliferation of glomerular basement membrane was obvious, the inflammatory cells were infiltrated, and glomerular sclerosis appeared;in tanshinone ⅡA group, glomerular basement membrane hyperplasia and inflammatory infiltration were not obvious in the mice, there was only small amount of infiltrated inflammatory cells. Compared with control group, the urine red blood cell count,the 24 h urine protein level,the p-ERK mRNA and AOPP protein levels of the mice in model group and tanshinone Ⅱ A group were increased(P<0.05 or P<0.01); the Cosmc mRNA expression levels were decreased (P<0.01). Compared with model group, the urine red blood cell count, 24 h urine protein level, the p-ERK and AOPP protein levels in the kidney tissue of the mice in tanshinone Ⅱ A group were decreased (P<0.05 or P<0.01), and the Cosmc mRNA expression level was increased (P<0.01). In model group, the Cosmc mRNA expression level in the kidney tissue was negatively correlated with the expression levels of AOPP protein and the expression level of p-ERK protein (r=-0.573, P<0.01; r=-0.602, P<0.01), and the level of AOPP protein was positively correlated with the expression level of p-ERK protein (r=0.614, P<0.01). Conclusion:Tanshinone Ⅱ A may play a role in the treatment of allergic purpura nephritis in the mice by lowering the levels of Cosmc,increasing the AOPP in kidney tissue and activating the ERK/MAPK signaling pathways.

Key words: tanshinone ⅡA, allergic purpura nephritis, mice, kidney, Cosmc, advanced oxidation protein, extracellular signal-regulated kinase, mitogen-activated protein kinase