Erythropoietin protects the tubular basement membrane by promoting the bone marrow to release extracellular vesicles containing tPA-targeting miR-144

Am J Physiol Renal Physiol. 2016 Jan 1;310(1):F27-40. doi: 10.1152/ajprenal.00303.2015. Epub 2015 Oct 14.

Abstract

Renal fibrosis is an inevitable outcome of chronic kidney disease (CKD). Erythropoietin (EPO) has been recently reported to be able to mitigate renal fibrosis. The mechanism underlying the protective effect of EPO, however, remains elusive. In the present study, employing a mouse model of renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction (UUO), we demonstrated that EPO markedly reduced the disruption of the tubular basement membrane (TBM) through attenuating the activation of tissue plasminogen activator (tPA) and matrix metalloproteinase 9 (MMP9), the major matrix proteolytic network in the obstructed kidney. Instead of acting directly on tPA in the kidney, EPO strongly increased the level of circulating microRNA (miR)-144, which was delivered to the injured renal fibroblasts via extracellular vesicles (EVs) to target the tPA 3'-untranslated region and suppress tPA expression. The protective effect of EPO on mouse TBM was inhibited by miR-144 antagomir. Furthermore, in vitro results confirmed that EPO could stimulate bone marrow-derived Sca-1(+)CD44(+)CD11b(-)CD19(-) cells to secrete miR-144-containing EVs, which markedly suppressed tPA expression, as well as metalloproteinase 9 (MMP9) level and activity, in cultured renal fibroblasts. In conclusion, our study provides the first evidence that EPO protects mouse renal TBM through promoting bone marrow cells to generate and secrete miR-144, which, in turn, is efficiently delivered into the mouse kidney via EVs to inhibit the activation of the tPA/MMP9-mediated proteolytic network. This finding thus suggests that EPO, a hormone widely used to treat anemia in CKD, is a potential therapeutic strategy for renal fibrosis.

Keywords: EPO; extracellular vesicle; miRNA; renal fibrosis; tubular basement membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Binding Sites
  • Bone Marrow Cells / drug effects*
  • Bone Marrow Cells / enzymology
  • Cell Line
  • Cytoprotection
  • Disease Models, Animal
  • Enzyme Activation
  • Enzyme Repression
  • Erythropoietin / pharmacology*
  • Extracellular Vesicles / drug effects*
  • Extracellular Vesicles / enzymology
  • Fibroblasts / drug effects
  • Fibroblasts / enzymology
  • Fibrosis
  • Glomerular Basement Membrane / drug effects*
  • Glomerular Basement Membrane / enzymology
  • Glomerular Basement Membrane / pathology
  • Kidney Diseases / enzymology
  • Kidney Diseases / genetics
  • Kidney Diseases / pathology
  • Kidney Diseases / prevention & control*
  • Kidney Tubules / drug effects*
  • Kidney Tubules / enzymology
  • Kidney Tubules / pathology
  • Male
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • MicroRNAs / blood
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Rats
  • Recombinant Proteins / pharmacology
  • Signal Transduction / drug effects
  • Tissue Plasminogen Activator / genetics
  • Tissue Plasminogen Activator / metabolism*
  • Ureteral Obstruction / drug therapy*
  • Ureteral Obstruction / enzymology
  • Ureteral Obstruction / genetics
  • Ureteral Obstruction / pathology

Substances

  • 3' Untranslated Regions
  • EPO protein, human
  • MIRN144 microRNA, human
  • MIRN144 microRNA, mouse
  • MIRN144 microRNA, rat
  • MicroRNAs
  • Recombinant Proteins
  • Erythropoietin
  • Tissue Plasminogen Activator
  • Matrix Metalloproteinase 9
  • Mmp9 protein, mouse