DsbA-L protects against diabetic renal injury through the adipo-renal axis

Disulfide-bond A oxidoreductase-like protein (DsbA-L) is an adiponectin-interacting protein that is highly expressed in adipose tissue. The adipo-renal axis involves adipocyte release of signaling molecules that are recruited to kidney and regulate kidney function. We have found that the DsbA-L modulated the progression of diabetic nephropathy, but the precise mechanism of this modulation is unknown. Here, the transgenic mice overexpressing DsbA-L protein in fat (fDsbA-L) were used to verify that the renoprotective role of DsbA-L whether by adipo-renal axis. Mice were divided into four groups: a normal (Control) group, STZ induced diabetic mice, fDsbA-L mice and diabetic fDsbA-L mice (n=6). Diabetes was induced in mice by STZ 100mg/kg and continued HFD feeding for 12 weeks. Compared with the control group, the weight, blood glucose,and urine protein levels and the pathological changes in the kidney tissue of diabetic mice were increased significantly, accompanied by increased NLRP3,caspase-1, IL-1{beta}, IL-18, FN, and Collagen1 mRNA and protein expression, which were reduced in diabetic fDsbA-L mice. Interestingly, the level of adiponectin in serum and kidney expression in diabetic mice was reduced significantly compared to that in the control group. However this change was reversed in diabetic fDsbA-L mice. These data suggest that the overexpression of DsbA-L in the adipocytes of mice can protect against diabetic renal injury through anti-inflammatory mediators,and may be mediated by the adipo-renal axis.