ALA/LA Protect Against DN db/db mice Oxidative Stress and Fibrosis Through the ROS/p38/TGF-β1 Pathway

Abstract

Abstract Objectives Both oxidative stress (OS) and fibrosis play a significant role in the pathobiology of diabetic nephropathy (DN). Hence, we observed the effects of a-linolenic acids/linoleic acid (ALA/LA) on renal oxidative stress and tubule fibrosis on DN db/db mice and clarified its possible mechanisms in vivo. Methods db/db and db/m mice were divided into four groups, including normal control group(db/m mice), DN model group(DN db/db mice), low-dose group (DN db/db mice intervened by 250 mg/kg.d mixture of ALA and LA, with the ratio of 1:4), high-dose group (DN db/db mice intervened by500mg/kg.d ALA/LA, with the ratio of 1:4). The effect of ALA/LA on DN db/db mice analyzed by ELISA, realtime PCR, Westen Blot and pathophysiology methods. Results Compared to the DN model group, after ALA/LA intervention, fasting plasma glucose, renal function, inflammation factors, the level of oxidative stress and the degree renal pathological morphology damage of db/db mice were lower in the intervention group(P < 0.05). The SOD, CAT, MDA level (nmol/mgprot) in intervention group was 11.97 ± 1.95, 20.13 ± 1.67, 0.81 ± 0.12, and that in the model group was5.87 ± 1.87, 12.37 ± 1.50, 1.07 ± 0.10. BUN, SCr, UA in intervention group was 19.21 ± 6.16 mmol/L, 30.86 ± 5.37μmol/L, 230.14 ± 56.44μmol/L; and that in the model group was 9.74 ± 3.77 mmol/L, 22.22 ± 3.9μmol/L, 172.56 ± 27.32μmol/L.Intervention of ALA/LA decreased the protein and mRNA expression of TGF-β1, p-p38 (p38), p-ERK (ERK) and COLⅣ in kidney of db/db mice (P < 0.05). The relative mRNA level of TGF-β1, p38, ERK and COLⅣ in the intervention group was 0.64 ± 0.14, 2.71 ± 0.15, 2.48 ± 0.47, 4.37 ± 0.71, while that in the model group was17.63 ± 4.84, 127.43 ± 4.84, 15.91 ± 3.55, 32.05 ± 4.13.The relative protein level of TGF-β1, p-p38, p-ERK and COL-Ⅳ in the intervention group was 0.42 ± 0.07, 0.13 ± 0.04, 0.35 ± 0.04, and 0.46 ± 0.03, while that in the model group was 0.74 ± 0.05, 0.90 ± 0.03, 0.98 ± 0.02, 1.06 ± 0.10. Conclusions ALA/LA(1:4, 250 mg/kg/d) has good antioxidant capacity in vivo. It inhibited the transduction action of p38 and ERK, reduced the activity of TGF-β1, COL-Ⅳand ameliorate kidney fibrosis of DN db/db mice. The study on ALA/LA might provide research evidence and possible clinical treatment for DN. Funding Sources This work was financially supported by the National Natural Science Foundation of China (No. 81,372,986).