Downregulation of microRNA-30 facilitates podocyte injury and is prevented by glucocorticoids

J Am Soc Nephrol. 2014 Jan;25(1):92-104. doi: 10.1681/ASN.2012111101. Epub 2013 Sep 12.

Abstract

MicroRNAs (miRNAs) are essential for podocyte homeostasis, and the miR-30 family may be responsible for this action. However, the exact roles and clinical relevance of miR-30s remain unknown. In this study, we examined the expression of the miR-30 family in the podocytes of patients with FSGS and found that all members are downregulated. Treating cultured human podocytes with TGF-β, LPS, or puromycin aminonucleoside (PAN) also downregulated the miR-30 family. Podocyte cytoskeletal damage and apoptosis caused by treatment with TGF-β or PAN were ameliorated by exogenous miR-30 expression and aggravated by miR-30 knockdown. Moreover, we found that miR-30s exert their protective roles by direct inhibition of Notch1 and p53, which mediate podocyte injury. In rats, treatment with PAN substantially downregulated podocyte miR-30s and induced proteinuria and podocyte injury; however, transfer of exogenous miR-30a to podocytes of PAN-treated rats ameliorated proteinuria and podocyte injury and reduced Notch1 activation. Finally, we demonstrated that glucocorticoid treatment maintains miR-30 expression in cultured podocytes treated with TGF-β, LPS, or PAN and in the podocytes of PAN-treated rats. Glucocorticoid-sustained miR-30 expression associated with reduced Notch1 activation and alleviated podocyte damage. Taken together, these findings demonstrate that miR-30s protect podocytes by targeting Notch1 and p53 and that the loss of miR-30s facilitates podocyte injury. In addition, sustained miR-30 expression may be a novel mechanism underlying the therapeutic effectiveness of glucocorticoids in treating podocytopathy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Dexamethasone / pharmacology
  • Disease Models, Animal
  • Down-Regulation / drug effects
  • Gene Knockdown Techniques
  • Glomerulosclerosis, Focal Segmental / drug therapy
  • Glomerulosclerosis, Focal Segmental / genetics
  • Glomerulosclerosis, Focal Segmental / pathology
  • Glucocorticoids / pharmacology
  • Humans
  • Lipopolysaccharides / pharmacology
  • MicroRNAs / antagonists & inhibitors
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism
  • Podocytes / drug effects
  • Podocytes / metabolism*
  • Podocytes / pathology
  • Puromycin Aminonucleoside / pharmacology
  • Rats
  • Rats, Wistar
  • Receptor, Notch1 / antagonists & inhibitors
  • Receptor, Notch1 / genetics
  • Transforming Growth Factor beta / metabolism
  • Tumor Suppressor Protein p53 / antagonists & inhibitors
  • Tumor Suppressor Protein p53 / genetics

Substances

  • Glucocorticoids
  • Lipopolysaccharides
  • MIRN30 microRNA, rat
  • MIRN30b microRNA, human
  • MicroRNAs
  • NOTCH1 protein, human
  • Receptor, Notch1
  • TP53 protein, human
  • Transforming Growth Factor beta
  • Tumor Suppressor Protein p53
  • Puromycin Aminonucleoside
  • Dexamethasone