p-coumaric acid alleviates diabetic nephropathy by inhibiting RhoA/ROCK signaling pathway
Objective To investigate the therapeutic effect of p-coumaric acid(p-CA)on diabetic nephropathy(DN)rats and its influence on Ras homolog gene family member A(RhoA)/Rho associated coiled-coil forming protein kinase(ROCK)signaling pathway.Methods Rats were divided into 6 groups:control group(n=10),DN group(n=10),low dose p-coumaric acid(L-p-CA)group(n=10),medium dose p-coumaric acid(M-p-CA)group(n=10),high dose p-coumaric acid(H-p-CA)group(n=10)and RhoA agonist U-46619 group(n=12).Rats in control group were healthy SD rats,and rats in the other groups were given high-fat diet combined with streptozotocin to induce DN models.After modeling,the rats in control group and DN group were intragastrically given 2 mL of 0.5%carboxymethyl cellulose solution,the rats in L-p-CA group,M-p-CA group and H-p-CA group were given intragastrically 2 mL of 50,100 and 200 mg/(kg d)p-coumaric acid solution respectively,and the rats in U-46619 group were simultaneously and intragastrically given 1 mL of p-coumaric acid solution[200 mg/(kg d)]and 1 mL of RhoA agonist U-46619[30 μg/(kg·d)].All the rats were intervened for 12 weeks.After treatment,the levels of biochemical indexes[fasting blood glucose(FPG),fasting insulin(FINS),glycosylated hemoglobin(HbA1c),urea nitrogen(BUN),blood creatinine(Cr)and 24-hour urinary protein]and serum oxidative stress indexes[superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-PX)and malondialdehyde(MDA)]were mea-sured.HE staining and Masson trichrome staining were used to evaluate renal injury and fibrosis in rats.The transcriptional activities of tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1β)and monocyte chemoattractant protein-1(MCP-1)in kidney were detected by qRT-PCR.The protein expression levels of TNF-α,IL-1β,MCP-1,RhoA and ROCK1 in kidney were detected by Western blot.Results Compared with control group,the levels of FPG,FINS,24 h urinary protein,HbA1c,BUN and Cr were increased in DN group(P<0.05),obvious pathological changes occurred in renal tissue,the area of renal fibrosis was increased(P<0.05),the serum levels of SOD,CAT and GSH-PX were decreased(P<0.05),MDA level was increased(P<0.05),the mRNA and protein levels of TNF-α,IL-1β and MCP-1 in renal tissue were increased(P<0.05),and the protein expression levels of RhoA and ROCK1 in renal tissue were increased(P<0.05).Compared with DN group,the levels of FPG,FINS,24 h urinary protein,HbA1c,BUN and Cr were decreased in L-p-CA group,M-p-CA group and H-p-CA group(P<0.05),renal pathological changes were alleviated,the area of renal fibrosis was decreased(P<0.05),the levels of SOD,CAT and GSH-PX in serum were increased(P<0.05),MDA level was decreased(P<0.05),the mRNA and protein levels of TNF-α,IL-1β and MCP-1 in renal tissue were decreased(P<0.05),and the protein expressions of RhoA and ROCK1 in renal tissue were decreased(P<0.05).Compared with L-p-CA group and M-p-CA group,the levels of FPG,FINS,24 h urinary protein,HbAlc,BUN and Cr were decreased in H-p-CA group(P<0.05),renal pathological changes were alleviated,the area of renal fibrosis was decreased(P<0.05),the levels of SOD,CAT and GSH-PX in serum were increased(P<0.05),MDA level was decreased(P<0.05),the mRNA and protein levels of TNF-α,IL-1β and MCP-1 in renal tissue were decreased(P<0.05),and the protein expressions of RhoA and ROCK1 in renal tissue were decreased(P<0.05).Compared with H-p-CA group,the levels of FPG,FINS,24 h urinary protein,HbA1c,BUN and Cr were increased in U-46619 group(P<0.05),renal pathological changes were aggravated,the area of renal fibrosis was increased(P<0.05),the levels of SOD,CAT and GSH-PX in serum were decreased(P<0.05),MDA level was increased(P<0.05),the mRNA and protein levels of TNF-α,IL-1β and MCP-1 in renal tissue were increased(P<0.05),and the protein expressions of RhoA and ROCK1 in renal tissue were increased(P<0.05).Conclusion The p-coumaric acid can attenuate the diabetic nephropathy by inhibiting RhoA/ROCK signal pathway.
p-coumaric aciddiabetic nephropathyRas homolog gene family member ARho associated coiled-coil forming protein kinaseoxidative stressinflammationfibrosis