Rolo of Osteoblastic Cells in Osteoclast Development.

(1)体外支持破骨细胞形成的基质细胞系的研究我们曾报道，在小鼠脾细胞与新鲜分离的小鼠颅骨成骨细胞共培养中，1 α，25（OH）_2D_3可诱导形成破骨样多核细胞（MNCs）（Endocrinology，123：2600，1988）。在这项研究中，我们研究了这种原代成骨细胞是否可以被已建立的细胞系所取代，以诱导破骨细胞样MNC的形成。两种骨髓基质细胞系MC 3 T3-G2/PA 6和ST 2在与脾细胞共培养时可支持破骨细胞样MNC的形成。此外，一个新的基质细胞系（KS 4），它支持破骨细胞样MNC的形成，在共培养，建立了从小鼠颅骨。KS 4细胞在长期培养中表现出成骨细胞的典型表型，如强烈的碱性磷酸酶活性，PTH依赖的cAMP产生和结节形成。(2)破骨细胞的起源 ...更多信息 使用与ST 2细胞的共培养系统的破骨细胞的起源。在ST 2细胞存在下，不仅骨髓中的未成熟造血细胞，而且外周血中的单核细胞和肺泡组织中的巨噬细胞也分化为破骨细胞样MNC。这表明破骨细胞是单核细胞-巨噬细胞家族的细胞。(3)集落刺激因子（CSF）对破骨细胞发育的影响我们观察了CSF（IL-3，GM-CSF，M-CSF，G-CSF）对破骨细胞祖细胞增殖和分化的影响。没有一个CSF刺激祖细胞分化成破骨细胞样MNC。然而，CSFs，尤其是M-CSF，能显著刺激前体细胞的增殖，最近发现骨硬化（op/op）小鼠M-CSF基因编码区发生突变。这表明op/op小鼠中破骨细胞缺乏是由于功能性M-CSF的产生失败。我们使用共培养系统检测了op/op小鼠中破骨细胞的形成。我们发现OP/OP小鼠的成骨细胞在与正常脾细胞共培养时不支持破骨细胞的形成。在共培养物中加入M-CSF可诱导破骨细胞样细胞的出现。这些结果表明，成骨细胞产生的M-CSF是破骨细胞发育所必需的。少

(1) Studies on stromal cell lines which support osteoclast formation in vitroWe previously reported that osteoclast-like multinucleated cells (MNCs) were formed in response to 1alpha, 25 (OH) _2D_3 in co-cultures of mouse spleen cells and osteoblastic cells freshly isolated from mouse calvariae (Endocrinology, 123 : 2600, 1988). In this study, we examined whether such primary osteoblastic cells can be replaced by established cell lines in inducing osteoclast-like MNC formation. Two bone marrow-derived stromal cell line, MC3T3-G2/PA6 and ST2, were found to suppoort osteoclast-like MNC formation in the co-culture with spleen cells. In addition, a new stromal cell line (KS4), which supports osteoclast-like MNC formation in the co-cultures, was established from mouse calvariae. KS4 cells exhibited typical phenotypes of osteoblasts such as intense alkaline phophatase activity, PTH-dependent cAMP production, and nodule formation in a long-term culture.(2) Origin of osteoclastsWe examined the … More origin of osteoclasts using the co-culture system with ST2 cells. Not only immature hematopoietic cells in bone marrow but also monocytoes in peripheral blood and macrophages in alveolar tissues differentiated into osteoclast-like MNCs in the presence of ST2 cells. This indicates that osteoclasts are the cells of the monocyte-macrophage family.(3) Effects of colony stimulating factors (CSFs) on osteoclast developmentWe examined the effects of CSFs (IL-3, GM-CSF, M-CSF, G-CSF) on the proliferation and the differentiation of osteoclast progenitors. None of the CSFs stimulated differentiation of the progenitors into osteoclast-like MNCs. However, the CSFs, especially M-CSF, markedly stimulated proliferation of the progenitors.The mutation of osteopetrotic (op/op) mice was recently found in the coding region of the M-CSF gene. This indicates that osteoclast deficiency in op/op mice is due to failure of the production of functional M-CSF. We examined osteoclast formation in op/op mice using the co-colture system. We found that osteoblastic cells from op/op mice did not support osteoclast formation in the co-cultures with normal spleen cells. Adding M-CSF to the co-cultures induced the appearance of osteoclast-like cells. These results indicate that M-CSF produced by osteoblastic cells is essential for osteoclast development. Less