Reduced Autophagy by a microRNA-mediated Signaling Cascade in Diabetes-induced Renal Glomerular Hypertrophy

Sci Rep. 2018 May 3;8(1):6954. doi: 10.1038/s41598-018-25295-x.

Abstract

Autophagy plays a key role in the pathogenesis of kidney diseases, however its role in diabetic nephropathy (DN), and particularly in kidney glomerular mesangial cells (MCs) is not very clear. Transforming Growth Factor- β1 (TGF-β), a key player in the pathogenesis of DN, regulates expression of various microRNAs (miRNAs), some of which are known to regulate the expression of autophagy genes. Here we demonstrate that miR-192, induced by TGF-β signaling, plays an important role in regulating autophagy in DN. The expression of key autophagy genes was decreased in kidneys of streptozotocin-injected type-1 and type-2 (db/db) diabetic mice and this was reversed by treatment with Locked Nucleic Acid (LNA) modified miR-192 inhibitors. Changes in autophagy gene expression were also attenuated in kidneys of diabetic miR-192-KO mice. In vitro studies using mouse glomerular mesangial cells (MMCs) also showed a decrease in autophagy gene expression with TGF-β treatment. miR-192 mimic oligonucleotides also decreased the expression of certain autophagy genes. These results demonstrate that TGF-β and miR-192 decrease autophagy in MMCs under diabetic conditions and this can be reversed by inhibition or deletion of miR-192, further supporting miR-192 as a useful therapeutic target for DN.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Autophagy*
  • Diabetes Mellitus, Experimental / complications*
  • Diabetes Mellitus, Experimental / genetics
  • Diabetes Mellitus, Experimental / pathology
  • Diabetic Nephropathies / etiology
  • Diabetic Nephropathies / genetics*
  • Diabetic Nephropathies / pathology
  • Gene Expression Regulation
  • Hypertrophy / genetics
  • Hypertrophy / pathology
  • Kidney Glomerulus / metabolism
  • Kidney Glomerulus / pathology*
  • Mice, Inbred C57BL
  • MicroRNAs / genetics*
  • Signal Transduction*

Substances

  • MicroRNAs
  • Mirn192 microRNA, mouse