title: Role of MEK-ERK pathway in sphingosylphosphorylcholine-induced cell death in human adipose tissue-derived mesenchymal stem cells.
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.
authors.affiliation: Department of Physiology, College of Medicine, Pusan National University, 1-Ga, Ami-Dong, Suh-Gu, Busan 602-739, Republic of Korea.
authors.forename: Eun Su
authors.initials: ES
authors.lastname: Jeon
authors.forename: Yong Jung
authors.initials: YJ
authors.lastname: Kang
authors.forename: Hae Young
authors.initials: HY
authors.lastname: Song
authors.forename: Jae Suk
authors.initials: JS
authors.lastname: Woo
authors.forename: Jin Sup
authors.initials: JS
authors.lastname: Jung
authors.forename: Yong Keun
authors.initials: YK
authors.lastname: Kim
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D047428:Protein Kinase Inhibitors; C005356:sphingosine phosphorylcholine; D010767:Phosphorylcholine; D045304:Cytochromes c; D017346:Protein Serine-Threonine Kinases; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D013110:Sphingosine