Renoprotective effect of transforming growth factor beta activator kinase 1 inhibitor in diabetic db/db mice and its mechanism / 中华肾脏病杂志

ABSTRACT

Objective To investigate the renoprotective effect of transforming growth factor beta activator kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (OZ) in diabetic db/db mice and the mechanism.Methods Twenty-four male db/db mice were randomly divided into two groupsdb/db mice (db/db,n=12) and db/db mice with 5Z-7-oxozeaenol treatment (db/db+OZ,n=12).Another group of wild type mice (n=12) was held as the control group.OZ 2 mg/kg was administrated by intraperitoneal injection every other day.At week 8 and 12 after 5Z-7-oxozeaenol treatment,blood glucose (BG),body weight (BW),kidney weight (KW) and urinary albumin excretion rate (UAER) were evaluated.Kidney pathological lesions were detected by light and electron microscopy.NF-κB p65,monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor-ot (TNF-o) were detected by immunohistochemistry.Western blotting was used to detect p-TAK1,TAB1,p-p38MAPK and IL-1β expression,while ICAM-1 and MCP-1 mRNA levels were evaluated by real-time PCR.Results Compared with control group,the levels of BG,BW,KW and UAER were higher (P ＜ 0.01) in db/db mice group,while BW,KW and UAER levels were significantly decreased in db/db + OZ group compared with that in db/db mice group (P ＜ 0.05).In week 8 and 12 db/db mice,glomerular volume and extracellular matrix were increased,while pathological lesions in kidney tissue were positively improved by TAK1 inhibitor.Immunohistochemistry showed that NF-κB p65,MCP-1 and TNF-α expression levels were apparently increased in db/db mice group compared with that in control group (P ＜ 0.05) and were significantly inhibited by TAK1 inhibitor (P ＜ 0.05).Western blotting showed that p-TAK1,TAB1,p-p38MAPK and IL-1β expression levels were higher in db/db mice group than that in control group (P ＜ 0.05) and lower in db/db+ OZ group than that in db/db mice group (P ＜ 0.05).Moreover,real-time PCR showed that the expressions of ICAM-1 and MCP-1 mRNA were higher in db/db mice group than that in control group and lower in db/db+OZ group than that in db/db mice group (P ＜0.05).Conclusions TAK1 Inhibitor can down-regulate MAPK and NF-κB pathway to restrain the reaction of inflammation and alleviate kidney injury in diabetic db/db mice.