title: Tissue inhibitor of matrix metalloproteinase-1 suppresses apoptosis of mouse bone marrow stromal cell line MBA-1.
abstract: We investigated the action of tissue inhibitor of metalloproteinase-1 (TIMP-1) on apoptosis and differentiation of mouse bone marrow stromal cell line MBA-1. TIMP-1 did not affect alkaline phosphatase (ALP) activity, suggesting that it is not involved in osteoblastic differentiation in MBA-1 cells. However, TIMP-1 inhibited MBA-1 apoptosis induced by serum deprivation in a dose-dependent manner. Our study also showed increased Bcl-2 protein expression and decreased Bax protein expression with TIMP-1 treatment. TIMP-1 decreased cytochrome c release and caspase-3 activation in MBA-1 cells. TIMP-1 activated phosphatidylinositol 3-kinase (PI3-kinase) and c-Jun N-terminal kinase (JNK), and the PI3-kinase inhibitor LY294002 or the JNK inhibitor SP600125 abolished its antiapoptotic activity. To investigate whether antiapoptotic action of TIMP-1 was mediated through its inhibition on MMP activities, we constructed mutant TIMP-1 by side-directed mutagenesis, which abolished the inhibitory activity of MMPs by deletion of Cys1 to Ala4. Wild-type TIMP-1 and mutant TIMP-1 expression plasmids were transfected in MBA-1 cells, and results showed that mutant TIMP-1 still protected the induced MBA-1 cell against apoptosis. These data suggest that TIMP-1 antiapoptotic actions are mediated via the PI3-kinase and JNK signaling pathways and independent of TIMP-1 inhibition of MMP activities.
authors.affiliation: Institute of Endocrinology and Metabolism, Second Xiangya Hospital of Central South University, 86 Middle Renmin Road, Changsha, Hunan, 410011, People's Republic of China.
authors.forename: L-J
authors.initials: LJ
authors.lastname: Guo
authors.forename: X-H
authors.initials: XH
authors.lastname: Luo
authors.forename: H
authors.initials: H
authors.lastname: Xie
authors.forename: H-D
authors.initials: HD
authors.lastname: Zhou
authors.forename: L-Q
authors.initials: LQ
authors.lastname: Yuan
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: E-Y
authors.initials: EY
authors.lastname: Liao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D001854:Bone Marrow Cells / Q000187:drug effects* / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D045304:Cytochromes c / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D009154:Mutation / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000187:drug effects* / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000187:drug effects / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D019715:Tissue Inhibitor of Metalloproteinase-1; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D019869:Phosphatidylinositol 3-Kinases; D048031:JNK Mitogen-Activated Protein Kinases; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases