Role of MEK-ERK pathway in sphingosylphosphorylcholine-induced cell death in human adipose tissue-derived mesenchymal stem cells

Biochim Biophys Acta. 2005 May 1;1734(1):25-33. doi: 10.1016/j.bbalip.2005.01.005. Epub 2005 Feb 24.

Abstract

Sphingosylphosphorylcholine (SPC) is a bioactive lipid molecule involved in a variety of cellular responses. In the present study, we demonstrated that treatment of human adipose tissue-derived mesenchymal stem cells (hATSCs) with D-erythro-SPC resulted in apoptosis-like cell death, as demonstrated by decreased cell viability, DNA strand breaks, the increase of sub-G1 fraction, cytochrome c release into cytosol, and activation of caspase-3. In contrast, the exposure of hATSCs to L-threo-SPC did not induce the cell death, suggesting that the SPC-induced cell death was selective for the D-erythro-stereoisomer of SPC. The D-erythro-SPC-induced cell death was prevented by DEVD-CHO, a caspase-3 specific inhibitor, and Z-VAD-FMK, a general caspase inhibitor, suggesting that the SPC-induced cell death of hATSCs occurs through the cytochrome c- and caspase-3-dependent pathways. In addition, D-erythro-SPC treatment stimulated the activation of mitogen-activated protein kinases, such as ERK and c-Jun NH2-terminal protein kinase (JNK), and the D-erythro-SPC-induced cell death was completely prevented by pretreatment with the MEK inhibitor, U0126, but not by pretreatment with the JNK inhibitor, SP600125, and the p38 MAPK inhibitor, SB202190, suggesting a specific involvement of ERK in the D-erythro-SPC-induced cell death. Pretreatment with U0126 attenuated the D-erythro-SPC-induced release of cytochrome c. From these results, we suggest that ERK is involved in the SPC-induced cell death of hATSC through stimulation of the cytochrome c/caspase-3-dependent pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / cytology
  • Adipose Tissue / metabolism*
  • Caspase 3
  • Caspases / metabolism
  • Cell Death / drug effects
  • Cells, Cultured
  • Cytochromes c / metabolism
  • Humans
  • MAP Kinase Signaling System / drug effects*
  • Phosphorylcholine / analogs & derivatives*
  • Phosphorylcholine / pharmacology*
  • Protein Kinase Inhibitors / pharmacology
  • Protein Serine-Threonine Kinases / metabolism*
  • Sphingosine / analogs & derivatives*
  • Sphingosine / pharmacology*
  • Stem Cells / cytology
  • Stem Cells / metabolism*

Substances

  • Protein Kinase Inhibitors
  • sphingosine phosphorylcholine
  • Phosphorylcholine
  • Cytochromes c
  • Protein Serine-Threonine Kinases
  • CASP3 protein, human
  • Caspase 3
  • Caspases
  • Sphingosine