Objective To investigate the effects of mechanical strain on ca^(2+)-calmodulin dependent kinase(caMK)-cA MP response element binding protein(cREB) signal pathway and proliferation of osteoblasts. Methods Using a four...
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Objective To investigate the effects of mechanical strain on ca^(2+)-calmodulin dependent kinase(caMK)-cA MP response element binding protein(cREB) signal pathway and proliferation of osteoblasts. Methods Using a four-point bending device, Mc3T3-E1 cells were exposed to mechanical tensile strains of 2500 μs and 5000 μs at 0.5 Hz respectively. The intracellular free ca^(2+)([ca^(2+)]i) concentration and calmodulin activity were assayed by fluorospectrophotometry, caMK II β, cREB, and phosphorylated(activated) cREB(p-cREB) were assessed by Western blot, and cells proliferation was assayed with MTT. Pretreatment with verapamil was carried out to block ca^(2+) channel, and inhibitor U73122 was used to inhibit phospholipase c(PLc). Results Mechanical strains of 2500 μs and 5000 μs for 1 to 10 minutes both increased [ca^(2+)]i level of the cells. The 2500 μs strain, a periodicity of 1 h/d for 3 days, activated calmodulin, elevated protein levels of caMK II β and p-cREB, and promoted cells proliferation, which were attenuated by pretreatment of verapamil or U73122. The effects of 5000 μs strain on calmodulin, caMK II β, p-cREB and proliferation were contrary to 2500 μs strain. conclusion The mechanical strain regulates osteoblasts proliferation through ca^(2+)-ca MK-cREB signal pathway via ca^(2+) channel and PLc/IP_3 transduction cascades.
RNA helicases, which unwind RNAs, are essential for RNA metabolism and homeostasis. However, the roles of RNA helicases in specific physiological processes remain poorly understood. We recently reported that an RNA he...
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RNA helicases, which unwind RNAs, are essential for RNA metabolism and homeostasis. However, the roles of RNA helicases in specific physiological processes remain poorly understood. We recently reported that an RNA helicase, HEL-1, promotes long lifespan conferred by reduced insulin/insulin-like growth factor-1 (IGF-1) signaling (IIS) in caenorhabditis elegans. We also showed that HEL-1 induces the expression of longevity genes by physically interacting with Forkhead box O (FOXO) transcription factor. Thus, the HEL-1 RNA helicase appears to regulate lifespan by specifically activating FOXO in IIS. In the current study, we report another longevity-promoting RNA helicase, Suppressor of AcY-4 sterility 1 (SAcY-1). SAcY-1 contributed to the longevity of daf-2/insulin/IGF-1 receptor mutants. Unlike HEL-1, SAcY-1 was also required for the longevity due to mutations in genes involved in non-IIS pathways. Thus, SAcY-1 appears to function as a general longevity factor for various signaling pathways, which is different from the specific function of HEL-1.
对关节镜及 c 臂 X 射线机导航下内固定治疗膝关节周围骨折的临床疗效进行探讨。方法:回顾性分析 2014-2015年于我院采取关节镜及 c 臂 X 射线机导航下内固定治疗膝关节周围骨折 50 例患者的治疗过程。结果:本组 50 例患者均在关节镜及...
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对关节镜及 c 臂 X 射线机导航下内固定治疗膝关节周围骨折的临床疗效进行探讨。方法:回顾性分析 2014-2015
年于我院采取关节镜及 c 臂 X 射线机导航下内固定治疗膝关节周围骨折 50 例患者的治疗过程。结果:本组 50 例患者均在关
节镜及 c 臂 X 射线机导航下行内固定治疗;无一例患者骨折愈合不良,术后行 X 线复查提示骨折对位对线良好。结论:兼具
良好临床效果与安全性的关节镜及 c 臂 X 射线机导航下内固定疗法是治疗膝关节周围骨折的理想选择,值得临床广泛应用与
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