Crosstalk between SDF-1/CXCR4 and SDF-1/CXCR7 in cardiac stem cell migration

Sci Rep. 2015 Nov 18:5:16813. doi: 10.1038/srep16813.

Abstract

Stromal cell-derived factor 1 (SDF-1) is a chemokine that can be expressed in injured cardiomyocytes after myocardial infarction (MI). By combining with its receptor CXCR4, SDF-1 induced stem and progenitor cells migration. CXCR7, a novel receptor for SDF-1, has been identified recently. We aimed to explore the roles of SDF-1/CXCR4 and SDF-1/CXCR7 pathway and their crosstalk in CSCs migration. In the present study, CXCR4 and CXCR7 expression were identified in CSCs. Transwell assay showed that SDF-1 caused CSCs migration in a dose- and time-dependent manner, which could be significantly suppressed by CXCR4 or CXCR7 siRNA. Phospho-ERK, phospho-Akt and Raf-1 significantly elevated in CSCs with SDF-1 stimulation. Knockdown of CXCR4 or CXCR7 significantly decreased phospho-ERK or phospho-Akt, respectively, and eventually resulted in the inhibition of CSCs migration. Moreover, western blot showed that MK2206 (Akt inhibitor) increased the expression of phospho-ERK and Raf-1, whereas PD98059 (ERK inhibitor) had no effect on phospho-Akt and Raf-1. GW5074 (Raf-1 inhibitor) upregulated the expression of phospho-ERK, but had no effect on phospho-Akt. The present study indicated that SDF-1/CXCR7/Akt and SDF-1/CXCR4/ERK pathway played important roles in CSCs migration. Akt phosphorylation inhibited Raf-1 activity, which in turn dephosphorylated ERK and negatively regulated CSCs migration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement* / genetics
  • Chemokine CXCL12 / metabolism*
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Gene Expression Regulation
  • Mice
  • Myoblasts, Cardiac / metabolism*
  • Protein Binding
  • Proto-Oncogene Proteins c-akt / metabolism
  • Proto-Oncogene Proteins c-raf / metabolism
  • Receptors, CXCR / genetics
  • Receptors, CXCR / metabolism*
  • Receptors, CXCR4 / genetics
  • Receptors, CXCR4 / metabolism*
  • Signal Transduction*

Substances

  • Chemokine CXCL12
  • Cmkor1 protein, mouse
  • Receptors, CXCR
  • Receptors, CXCR4
  • Proto-Oncogene Proteins c-akt
  • Proto-Oncogene Proteins c-raf
  • Extracellular Signal-Regulated MAP Kinases