Department of Orthopedic Surgery, University of Regensburg, Asklepios Klinikum Bad Abbach, Germany.
Calcif Tissue Int. 2011 Sep;89(3):211-20. doi: 10.1007/s00223-011-9508-y. Epub 2011 Jun 15.
Survivin, the smallest member of the inhibitor of apoptosis gene family, is critical for the regulation of mitosis and maintenance of cell viability during embryonic development and cancer, while not being detectable in most adult differentiated tissues. We know little about whether survivin plays any physiological or pathophysiological role in the adult musculoskeletal system. We studied the expression of survivin in primary human osteoblastic cells and its biological functions in vitro. Survivin was detected by immunoblotting and real-time PCR. Subcellular localization was analyzed by immunofluorescence. Transfection of siRNA and plasmids coding for wild-type survivin was performed to study survivin function, i.e., proliferation and apoptosis assays. Survivin mRNA and protein are expressed in primary human osteoblastic cells. During interphase survivin localizes predominantly to the cytoplasmic compartment, which is relevant for the organization of the spindle apparatus during mitosis. Survivin knockdown resulted in an arrest of the cell cycle at the G(2)/M phase and increased rates of apoptosis. Elevated levels of survivin in primary human osteoblasts enhanced proliferation and cell viability. Taken together, we demonstrate for the first time that survivin is expressed in primary human osteoblastic cells on the mRNA and protein levels. Our results indicate that survivin is a critical factor for cell division and cell viability in primary human osteoblastic cells. Learning more about survivin's role in human osteoblasts could be an important step toward understanding the complex processes involved in bone homeostasis and remodeling.
Survivin，凋亡抑制基因家族中最小的成员，对于有丝分裂的调节和胚胎发育及癌症期间细胞活力的维持至关重要，而在大多数成年分化组织中无法检测到。我们对 survivin 在成人肌肉骨骼系统中是否发挥任何生理或病理生理作用知之甚少。我们研究了 survivin 在原代人成骨细胞中的表达及其在体外的生物学功能。通过免疫印迹和实时 PCR 检测 survivin 的表达。通过免疫荧光分析细胞内定位。通过转染 siRNA 和编码野生型 survivin 的质粒来研究 survivin 功能，即增殖和凋亡测定。Survivin mRNA 和蛋白在原代人成骨细胞中表达。在间期，survivin 主要定位于细胞质区室，这与有丝分裂期间纺锤体装置的组织有关。Survivin 敲低导致细胞周期停滞在 G2/M 期，并增加凋亡率。原代人成骨细胞中 survivin 水平的升高增强了增殖和细胞活力。总之，我们首次证明 survivin 在原代人成骨细胞中在 mRNA 和蛋白水平上表达。我们的结果表明，survivin 是人原代成骨细胞中细胞分裂和细胞活力的关键因素。更多地了解 survivin 在人成骨细胞中的作用可能是理解骨稳态和重塑所涉及的复杂过程的重要步骤。
