Atrasentan increased the expression of klotho by mediating miR-199b-5p and prevented renal tubular injury in diabetic nephropathy

Wen-Ling Kang,Gao-Si Xu

doi:10.1038/srep19979

Abstract

Atrasentan is a promising therapy for treating diabetic nephropathy (DN). Here we evaluated whether atrasentan down-regulated the miR-199b-5p expression, thereby increasing klotho and preventing renal tubular injury in DN. One-hundred patients with type 2 diabetes mellitus (T2DM) and 40 healthy subjects were included. A DN mice model was established by an injection of streptozotocin (STZ). Human renal proximal tubular epithelial HK-2 cells were exposed to high glucose (20 mmol/L). Treated the mice and HK-2 cells with atrasentan, and we then investigated whether and how miR-199b-5p and Klotho were involved in preventing renal tubular injury in DN. In patients, the serum miR-199b-5p level increased and the klotho concentration decreased in accordance with elevated albuminuria. Atrasentan down-regulated miR-199b-5p and up-regulated klotho of the DN mice and HK-2 cells exposed to high glucose. High glucose promoted the binding of histone H3 to the miR-199b-5p promoter, and atrasentan canceled this effect. MiR-199b-5p targeted the 3′ UTR of klotho. Overexpression of miR-199b-5p canceled the effects of atrasentan on klotho expression and apoptosis of renal tubular cells in both in vivo and in vitro. The increased serum klotho, mediated by miR-199b-5p, is a possible mechanism by which atrasentan prevents renal tubular injury in DN.

Highlights

Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes mellitus (DM) and results in progressive renal failure[1]
We focused on the function of miR-199b-5p in the regulation of klotho expression in renal tubular injury of diabetic nephropathy (DN)
We observed that high glucose increased histone H3 acetylation in the miR-199b-5p promoter region, which led to the activation of this miRNA

Summary

Introduction

Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes mellitus (DM) and results in progressive renal failure[1]. Little is known about the mechanism by which atrasentan protects against tubular injury during the pathological process of DN. Studies have demonstrated that this antiaging transmembrane protein was confirmed to be highly expressed in the kidney and presented in the proximal tubule lumen[10,12]. The roles of klotho in DM and renal diseases have attracted increased attention[13]. A clinical trial suggested that plasma klotho was inversely correlated with pro-endothelin-1 in T2DM patients. MiR-199b-5p has been found to target klotho in cancer[18]. We investigated whether the promoter histone deacetylases of miR-199b-5p contributed to the alteration of its expression and whether they were involved in the regulation of klotho in renal tubular injury during DN process. We speculated that regulation of miR-199b-5b and klotho might explain the beneficial effects of atrasentan in the treatment of DN

Methods

Results

Conclusion