A novel mechanism by which SDF-1β protects cardiac cells from palmitate-induced endoplasmic reticulum stress and apoptosis via CXCR7 and AMPK/p38 MAPK-mediated interleukin-6 generation

Diabetes. 2013 Jul;62(7):2545-58. doi: 10.2337/db12-1233. Epub 2013 Feb 19.

Abstract

We studied the protective effect of stromal cell-derived factor-1β (SDF-1β) on cardiac cells from lipotoxicity in vitro and diabetes in vivo. Exposure of cardiac cells to palmitate increased apoptosis by activating NADPH oxidase (NOX)-associated nitrosative stress and endoplasmic reticulum (ER) stress, which was abolished by pretreatment with SDF-1β via upregulation of AMP-activated protein kinase (AMPK)-mediated p38 mitogen-activated protein kinase (MAPK) phosphorylation and interleukin-6 (IL-6) production. The SDF-1β cardiac protection could be abolished by inhibition of AMPK, p38 MAPK, or IL-6. Activation of AMPK or addition of recombinant IL-6 recaptured a similar cardiac protection. SDF-1β receptor C-X-C chemokine receptor type 4 (CXCR4) antagonist AMD3100 or CXCR4 small interfering RNA could not, but CXCR7 small interfering RNA completely abolished SDF-1β's protection from palmitate-induced apoptosis and activation of AMPK and p38 MAPK. Administration of SDF-1β to diabetic rats, induced by feeding a high-fat diet, followed by a small dose of streptozotocin, could significantly reduce cardiac apoptosis and increase AMPK phosphorylation along with prevention of diabetes-induced cardiac oxidative damage, inflammation, hypertrophy, and remodeling. These results showed that SDF-1β protects against palmitate-induced cardiac apoptosis, which is mediated by NOX-activated nitrosative damage and ER stress, via CXCR7, to activate AMPK/p38 MAPK-mediated IL-6 generation. The cardiac protection by SDF-1β from diabetes-induced oxidative damage, cell death, and remodeling was also associated with AMPK activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylate Kinase / metabolism*
  • Animals
  • Apoptosis / drug effects*
  • Benzylamines
  • Cell Line
  • Chemokine CXCL12 / metabolism*
  • Chemokine CXCL12 / pharmacology
  • Cyclams
  • Diabetes Mellitus, Experimental / metabolism
  • Diet, High-Fat
  • Endoplasmic Reticulum Stress / drug effects*
  • Heterocyclic Compounds / pharmacology
  • Interleukin-6 / metabolism*
  • Interleukin-6 / pharmacology
  • Male
  • NADPH Oxidases / metabolism
  • Palmitic Acid / pharmacology
  • Phosphorylation / drug effects
  • Rats
  • Rats, Wistar
  • Receptors, CXCR / metabolism*
  • Receptors, CXCR4 / antagonists & inhibitors
  • Receptors, CXCR4 / metabolism
  • Signal Transduction / drug effects
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • Ackr3 protein, rat
  • Benzylamines
  • Chemokine CXCL12
  • Cxcr4 protein, rat
  • Cyclams
  • Heterocyclic Compounds
  • Interleukin-6
  • Receptors, CXCR
  • Receptors, CXCR4
  • Palmitic Acid
  • NADPH Oxidases
  • p38 Mitogen-Activated Protein Kinases
  • Adenylate Kinase
  • plerixafor