Yamashita T, Ishii H, Shimoda K, Sampath T K, Katagiri T, Wada M, Osawa T, Suda T
Pharmaceutical Research Laboratory, Kirin Brewery Co., Ltd., Gunma, Japan.
Bone. 1996 Nov;19(5):429-36. doi: 10.1016/s8756-3282(96)00255-4.
Three distinct osteoblastic cell lines (KS418, KS460, and KS483) were subcloned from the mouse osteoblastic KS-4 cells, which possessed the abilities not only to differentiate into mature osteoblasts, but also to support osteoclast differentiation in coculture with spleen cells. The order of the magnitude of the basal alkaline phosphatase (ALP) activity was KS483 > KS418 > KS460. KS483 cells were also more differentiated than KS418 and KS460 in terms of ALP activity and osteocalcin production, when cultured in growth medium containing 10% fetal bovine serum. In long-term culture, KS418 and KS483 apparently differentiated into mature osteoblasts and formed calcified nodules without addition of beta-glycerophosphate. Electron microscopic analysis demonstrated that calcification occurring in the nodules was initiated in the matrix vesicles as observed in bone formation in vivo. Nodule formation and mineral deposition occurred simultaneously in the presence of beta-glycerophosphate, but the former always preceded the latter without addition of beta-glycerophosphate. In contrast, KS460 cells did not show time-dependent increases of ALP activity, type I collagen expression and osteocalcin production, which were induced by treatment with recombinant osteogenic protein-1 (OP-1). The three cell lines similarly supported osteoclast differentiation in coculture with spleen cells in response to 1,25-dihydroxyvitamin D3. These results indicate that the three cell lines subcloned from the original KS-4 cells represent phenotypically distinct osteoblasts during osteoblast differentiation, but are equipped similarly with the capacity to support osteoclast differentiation. The subcloned cells of the KS-4 series may provide useful systems in which to study osteoblast differentiation and function.
从具有不仅能分化为成熟成骨细胞，还能在与脾细胞共培养时支持破骨细胞分化能力的小鼠成骨细胞系KS-4中，亚克隆出了三种不同的成骨细胞系（KS418、KS460和KS483）。基础碱性磷酸酶（ALP）活性的大小顺序为KS483 > KS418 > KS460。当在含有10%胎牛血清的生长培养基中培养时，就ALP活性和骨钙素产生而言，KS483细胞也比KS418和KS460细胞分化程度更高。在长期培养中，不添加β-甘油磷酸时，KS418和KS483明显分化为成熟成骨细胞并形成钙化结节。电子显微镜分析表明，结节中发生的钙化起始于基质小泡，这与体内骨形成中观察到的情况相同。在存在β-甘油磷酸的情况下，结节形成和矿物质沉积同时发生，但不添加β-甘油磷酸时，前者总是先于后者。相比之下，KS460细胞未显示出重组成骨蛋白-1（OP-1）处理诱导的ALP活性、I型胶原蛋白表达和骨钙素产生的时间依赖性增加。这三种细胞系在与脾细胞共培养时，对1,25-二羟基维生素D3的反应类似地支持破骨细胞分化。这些结果表明，从原始KS-4细胞亚克隆出的这三种细胞系在成骨细胞分化过程中代表表型不同的成骨细胞，但在支持破骨细胞分化的能力方面类似。KS-4系列的亚克隆细胞可能为研究成骨细胞分化和功能提供有用的系统。
