Proliferating cells in the primary spongiosa express osteoblastic phenotype in vitro.
Proliferating cells in the primary spongiosa express osteoblastic phenotype in vitro.
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DOI：
10.1016/s8756-3282(96)00350-x
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发表时间：
1997-02
期刊：
影响因子：
4.1
通讯作者：
J. Onyia;Bernard V. Miller;J. Hulman;Jingdong Liang;R. Galvin;Charles A. Frolik;Srinivasan Chandrasekhar;Anita K. Harvey;Joseph P. Bidwell;J. Herring;J. M. Hock
中科院分区：
文献类型：
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作者：
J. Onyia;Bernard V. Miller;J. Hulman;Jingdong Liang;R. Galvin;Charles A. Frolik;Srinivasan Chandrasekhar;Anita K. Harvey;Joseph P. Bidwell;J. Herring;J. M. Hock
我们已经证明，间歇性甲状旁腺激素（PTH）治疗的目标是幼鼠小梁骨原代spogiosa中的增殖细胞，导致成骨细胞数量增加。为了进一步表征这些增殖的骨祖细胞，体内掺入的溴脱氧尿苷（BrdUrd）被用作体外研究中鉴定和分离细胞的标记物。用BrdUrd在幼龄大鼠体内标记增殖细胞，24小时后通过胰酶化股骨远端干骺端原代海绵切片分离增殖细胞。在分离12 h内，BrdUrd+细胞形成明显的病灶，包含20-500个成纤维细胞形态的细胞。通过[3H]-胸腺嘧啶掺入，我们观察到这些细胞对胎牛血清、血小板衍生生长因子和转化生长因子β-1的反应产生了增殖刺激。胰岛素样生长因子-1 （IGF-1）和胰岛素均不刺激PTH（1-34）和地塞米松抑制增殖。甲状旁腺激素与地塞米松的作用是叠加的。细胞表达成骨细胞表型，证明了I型胶原的合成，高碱性磷酸酶活性的表达，以及在PTH反应中细胞内cAMP的增加（1-34）。在没有诱导剂的情况下，融合细胞聚集体在4-7天内自发形成矿化结节。这些观察结果表明，原代海绵状细胞在体外以加速的方式再现了分化过程，可以作为研究成骨细胞分化的有用模型。
We have shown that intermittent parathyroid hormone (PTH) treatment targets proliferating cells in the primary spogiosa of trabecular bone of young rats, resulting in an increased number of osteoblasts. To further characterize these proliferating osteoprogenitor cells, bromodeoxyuridine (BrdUrd) incorporated in vivo, was used as a marker to identify and isolate cells for in vitro studies. Proliferating cells were labeled in vivo in young rats with BrdUrd and 24 h later were isolated by trypsinization of sections of the primary spongiosa of the distal femur metaphysis. Within 12 h of isolation, BrdUrd+ cells formed distinct foci containing 20–500 cells with fibroblast morphology. Stimulation of proliferation as determined by [3H]-thymidine incorporation was observed for these cells in response to fetal bovine serum, platelet derived growth factor, and transforming growth factor β-1. Neither insulin-like growth factor-1 (IGF-1) nor insulin stimulated proliferation PTH (1–34) and dexamethasone inhibited proliferation. The effects of PTH and dexamethasone were additive. Cells expressed the osteoblast phenotype as evidenced by synthesis of type I collagen, expression of high alkaline phosphatase activity, and production of increased intracellular cAMP in response to PTH (1–34). Confluent cell aggregates spontaneously formed mineralized nodules within 4–7 days, in the absence of inducers. These observations suggest that the primary spongiosa cells recapitulates the differentiation process in vitro in an accelerated fashion and may serve as a useful model to study osteoblast differentiation.