[Bone morphogenetic protein signal transduction pathway regulates runx2 expression in MC3T3 -E1 osteoblasts in vitro induced by centrifugation].

OBJECTIVE: To observe the expression of Runx2 in osteoblasts in response to centrifugation in vitro and discuss the function of bone morphogenetic protein (BMP) signal transduction pathway in this course. METHODS: Cells were divided into four groups, group A, B, C and D, pretreated with DMEM containing 10% fetal bovine serum, 10% fetal bovine serum, 100 ng x mL(-1) Noggin and 100 ng x mL(-1) Noggin for 24 hours separately. 271 x g centrifugation was loaded for 5 min to these groups except group A and C, other conditions were the same. The total RNA of each group were extracted, and reversed transcription to cDNA after 30 min. The expression of Runx2 in response to centrifugation in vitro was analyzed by quantitative real time PCR. RESULTS: The expression of Runx2 mRNA in group B was significantly higher than that in group A (P < 0.05). The expression of Runx2 mRNA in group D was significantly lower than that in group B (P < 0.05). There was no statistically significant difference among group A, C, D (P = 0.692). CONCLUSION: BMP signal transduction pathway plays an important role in the response of osteoblasts to mechanical stimulations. It may also play a central role in the cascade information dissemination of osteoblasts.

Bis(µ-2-hydroxy-benozato)-κO,O':O';κO:O,O'-bis-[(2-hydroxy-benozato-κO,O')(1,10-phenanthroline-κN,N')cadmium(II)].

The dinuclear title compound, [Cd(2)(C(7)H(5)O(3))(4)(C(12)H(8)N(2))(2)], is located on a crystallographic rotation twofold axis. The two Cd(II) ions are connected by two tridentate bridging 2-hydroxy-benzoate anions. Each Cd(II) ion is seven-coordinated by five O atoms from three 2-hydroxy-benzoate ligands and two N atoms from 1,10-phenanthroline. The 2-hydroxy-benzoate mol-ecules adopt two kinds of coordination mode, bidentate chelating and tridentate bridging-chelating. Intra-molecular hydrogen bonds between hydr-oxy and carboxyl-ate groups from 2-hydroxy-benzoate groups and π-π stacking interactions between parallel 1,10-phenanthroline ligands [centroid-centroid distances = 3.707 (3) and 3.842 (3) Å] are observed. Furthermore, adjacent benzene rings from 2-hydroxy-benzoate ligands are involved in π-π inter-actions with inter-planar distances of 3.642 (3) Å, thereby forming a chain along the a axis direction.