THE ROLE OF CADHERIN IN THE GENERATION OF MULTINUCLEATED OSTEOCLASTS FROM MONONUCLEAR PRECURSORS IN MURINE MARROW
THE ROLE OF CADHERIN IN THE GENERATION OF MULTINUCLEATED OSTEOCLASTS FROM MONONUCLEAR PRECURSORS IN MURINE MARROW
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DOI：
10.1172/jci117979
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发表时间：
1995-06-01
影响因子：
15.9
通讯作者：
YONEDA, T
中科院分区：
文献类型：
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作者：
MBALAVIELE, G;CHEN, H;YONEDA, T
骨吸收的关键步骤是单核破骨细胞前体融合形成多核破骨细胞。然而，对这一重要过程的分子机制知之甚少。由于蛋白质的表达在钙粘蛋白家族中的嗜同性钙依赖性细胞粘附分子参与了某些其他细胞的融合过程，我们研究了它们在破骨细胞形成中的作用。免疫组织化学检查的人和小鼠骨使用单克隆抗体的人和小鼠E-钙粘蛋白清楚地表明阳性染色的破骨细胞。未检测到N-和P-钙粘蛋白。在小鼠骨髓单个核细胞，其中破骨细胞形成的细胞融合，E-cadherin表达蛋白质印迹法测定达到最高水平的融合发生。聚合酶链反应检测骨髓培养物中E-钙粘蛋白基因片段的表达。为了研究E-钙粘蛋白表达在破骨细胞分化中的功能作用，检测了中和性单克隆抗体对破骨细胞形成的影响。这些抗体通过抑制单核破骨细胞前体的融合，但不抑制这些细胞的增殖或它们附着在塑料培养皿表面上，从而减少抗酒石酸酸性磷酸酶（鼠破骨细胞的标志物）阳性多核细胞（TRAP阳性MNC）的数量。这种抑制作用是可逆的。此外，含有钙粘蛋白的细胞粘附识别序列的合成肽也减少TRAP阳性MNC的形成。抗体和肽不仅抑制破骨细胞的形成，而且还抑制骨吸收。其他类型的钙粘蛋白抗体和对照大鼠IgG在这些培养系统中没有影响。我们的研究结果表明，E-cadherin表达可能参与造血破骨细胞前体融合（分化）成成熟的多核破骨细胞。
A critical step in bone resorption is the fusion of mononuclear osteoclast precursors to form multinucleated osteoclasts. However, little is known of the molecular mechanisms that are responsible for this important process. Since the expression of proteins in the cadherin family of homophilic calcium-dependent cell adhesion molecules is involved in the fusion process for certain other cells, we examined their role in osteoclast formation. Immunohistochemical examination of human and mouse bone using monoclonal antibodies to human and mouse E-cadherin clearly demonstrated positive staining in osteoclasts. N- and P-cadherin were not detected. In cultures of murine marrow mononuclear cells in which osteoclasts form by cell fusion, E-cadherin expression determined by Western blotting reached the highest levels as fusion was taking place. Expression of E-cadherin gene fragment was also detected in the marrow cultures by polymerase chain reaction. To study the functional role of E-cadherin expression in osteoclastic differentiation, neutralizing monoclonal antibodies were examined for their effects on osteoclast formation. The antibodies decreased the number of tartrate-resistant acid phosphatase (a marker of murine osteoclast)-positive multinucleated cell (TRAP-positive MNC) by inhibiting the fusion of mononuclear osteoclast precursors, but not proliferation of these cells or their attachment to plastic dish surfaces. This inhibitory effect was reversible. Furthermore, synthetic peptides containing the cell adhesion recognition sequence of cadherins also decreased TRAP-positive MNC formation. The antibodies and peptides inhibited not only osteoclast formation but also bone resorption. Antibodies to other types of cadherins and control rat IgG had no effects in these culture systems. Our findings suggest that E-cadherin expression may be involved in fusion (differentiation) of hemopoietic osteoclast precursors into mature multinucleated osteoclasts.