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.

Serum omentin-1 was negatively correlated with FBM and BMI in healthy Chinese male adults, It was not significantly correlated with bone turnover biochemical markers. Omentin-1 may exert ambiguous effects on BMD, which maybe caused by the complex interactions among adipokines, hormonal activity, and body composition and bone metabolism.

ABSTRACT. We aimed to explore the association between the onset of ankylosing spondylitis (AS) and nt587 polymorphisms of the tumor necrosis factor receptor II (TNFRII) gene in the Han population of Hunan Province, China. Correlation analysis was performed in a case-control study involving 100 AS cases and 100 healthy controls. The nt587 single nucleotide polymorphism of the TNFRII gene was examined by polymerase chain reaction-restriction fragment length polymorphism. The relationship between AS and the frequencies of genotypes and alleles in TNFRII nt587 were analyzed using the SPSS software. There were 43 cases with the TNFRII nt587 T/T genotype, 32 cases with the TNFRII nt587 T/G genotype, and 25 cases with the TNFRII nt587 G/G genotype. In the 100 healthy controls, 56 subjects had the TNFRII nt587 5191 ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (3): 5190-5198 (2014) Relationship between TNFRII polymorphisms and AS T/T genotype, 34 had the TNFRII nt587 T/G genotype, and 10 had the TNFRII nt587 G/G genotype. The G allele frequency of the AS group was significantly higher (χ 2 = 8.734, P = 0.003) than that in the control group (41.0 vs 27.0%). The odds ratio (OR) in AS cases with the TNFRII nt587 G/G genotype was 3.256, which was obviously higher than in those with T/G (OR = 1.226) and T/T (OR = 1.0) genotype. The polymorphism at position nt587 of the TNFRII gene was found to be associated with AS, and the TNFRII nt587 G allele may play an important role in AS susceptibility. The TNFRII nt587 G/G genotype may increase the risk of developing AS in the Hunan population.