A soluble receptor for advanced glycation end-products inhibits myocardial apoptosis induced by ischemia/reperfusion via the JAK2/STAT3 pathway

Apoptosis. 2015 Aug;20(8):1033-47. doi: 10.1007/s10495-015-1130-4.

Abstract

sRAGE can protect cardiomyocytes from apoptosis induced by ischemia/reperfusion (I/R). However, the signaling mechanisms in cardioprotection by sRAGE are currently unknown. We investigated the cardioprotective effect and potential molecular mechanisms of sRAGE inhibition on apoptosis in the mouse myocardial I/R as an in vivo model and neonatal rat cardiomyocyte subjected to ischemic buffer as an in vitro model. Cardiac function and myocardial infarct size following by I/R were evaluated with echocardiography and Evans blue/2,3,5-triphenyltetrazolium chloride. Apoptosis was detected by TUNEL staining and caspase-3 activity. Expression of the apoptosis-related proteins p53, Bax, Bcl-2, JAK2/p-JAK2, STAT3/p-STAT3, AKT/p-AKT, ERK/p-ERK, STAT5A/p-STAT5A and STAT6/p-STAT6 were detected by western blot analysis in the presence and absence of the JAK2 inhibitor AG 490. sRAGE (100 µg/day) improved the heart function in mice with I/R: the left ventricular ejection fraction and fractional shortening were increased by 42 and 57%, respectively; the infarct size was decreased by 52%, the TUNEL-positive myocytes by 66%, and activity of caspase-3 by 24%, the protein expression of p53 and ratio of Bax to Bcl-2 by 29 and 88%, respectively; protein expression of the p-JAK2, p-STAT3 and p-AKT were increased by 92, 280 and 31%, respectively. sRAGE have no effect on protein expression of p-ERK1/2, p-STAT5A and p-STAT6 following by I/R. sRAGE (900 nmol/L) exhibited anti-apoptotic effects in cardiomyocytes by decreasing TUNEL-positive myocytes by 67% and caspase-3 activity by 20%, p53 protein level and the Bax/Bcl-2 ratio by 58 and 86%, respectively; increasing protein expression of the p-JAK2 and p-STAT3 by 26 and 156%, respectively, p-AKT protein level by 33%. The anti-apoptotic effects of sRAGE following I/R were blocked by JAK2 inhibitor AG 490. The effect of sRAGE reduction on TUNEL-positive myocytes and caspase-3 activity were abolished by PI3K inhibitor LY294002, but not ERK 1/2 inhibitor PD98059. These results suggest that sRAGE protects cardiomyocytes from apoptosis induced by I/R in vitro and in vivo by activating the JAK2/STAT3 signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn
  • Apoptosis Regulatory Proteins / metabolism
  • Apoptosis*
  • Chromones / pharmacology
  • Flavonoids / pharmacology
  • Gene Expression / drug effects
  • Janus Kinase 2 / metabolism
  • Male
  • Mice, Inbred C57BL
  • Morpholines / pharmacology
  • Myocardium / metabolism*
  • Myocytes, Cardiac / metabolism
  • Peptide Fragments / pharmacology
  • Rats, Sprague-Dawley
  • Receptor for Advanced Glycation End Products / metabolism*
  • Reperfusion Injury / metabolism*
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction*
  • Tyrphostins / pharmacology

Substances

  • Apoptosis Regulatory Proteins
  • Chromones
  • Flavonoids
  • Morpholines
  • Peptide Fragments
  • Receptor for Advanced Glycation End Products
  • STAT3 Transcription Factor
  • Stat3 protein, mouse
  • Stat3 protein, rat
  • Tyrphostins
  • alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide
  • protein kinase inhibitor peptide (5-24)
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Jak2 protein, mouse
  • Jak2 protein, rat
  • Janus Kinase 2
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one