缺氧大鼠成骨细胞增殖、分化及基因表达

Proliferation,differentiation and gene expression of osteoblasts in hypoxic rats

背景:研究表明,低氧会引起骨折延迟愈合或不愈合,骨密度减低,使骨质疏松、骨折等疾病的发病率升高。成骨细胞是骨形成、生长和发育主要的功能细胞。目的:观察缺氧对体外培养成骨细胞增殖、分化及基因表达的影响。方法:选用新生Wistar大鼠颅盖骨,使用胰酶-胶原酶序贯消化法获取成骨细胞,进行体外传代培养及鉴定。在缺氧培养下应用MTT法测定成骨细胞增殖率,对硝基苯磷酸盐法测定成骨细胞碱性磷酸酶活性,反转录-聚合酶链反应法测定成骨细胞内骨钙素及Ⅰ型胶原的表达。结果与结论:缺氧具有抑制成骨细胞增殖,降低碱性磷酸酶活性及下调大鼠成骨细胞中Ⅰ型胶原α1、骨钙素基因表达的作用,随缺氧时间的增加作用更加明显。提示缺氧可通过抑制成骨细胞增殖、分化成熟及下调Ⅰ型胶原α1、骨钙素基因表达而降低成骨能力,从而促进骨质疏松的发生。

BACKGROUND：Several researches have shown that hypoxia can lead to the healing of fracture delayed or non healing,and reduce bone density,which will improve the incidence of osteoporosis and fracture.OBJECTIVE：To investigate the effects of hypoxia on the proliferation,differentiation and gene expression of osteoblasts cultured in vitro.METHODS：The cranium from a newborn Wistar rat was collected and osteoblasts were extracted by trypsogen-collagenase sequential digestion method.The cells were subcultured in vitro and identified.The reproductive rate of osteoblasts was tested by MTT assay.Alkaline phosphatase activity of osteoblasts was detected by nitrophenylphosphate method.Bone gamma-carboxyglutamic-acid-containing proteins（BGP） and typeⅠcollagen expression were measured by reverse transcription-PCR method.RESULTS AND CONLUSION：Our studies revealed that hypoxia could inhibit the proliferation of osteoblasts and reduce alkaline phosphatase activity as well as decrease the expression of BGP mRNA and type Ⅰcollagen mRNA in a time-dependent manner.These findings suggest that hypoxia can inhibit the proliferation and differentiation of osteoblasts cultured in vitro and decrease the expression of BGP mRNA and typeⅠcollagen,which will decrease osteogenic ability and promote the incidence of osteoporosis.