Osteoclast Differentiation initiated at late-stage of mitosisof progenitor cells : Molecular mechanism of divergence from cell cycle

破骨细胞分化在祖细胞有丝分裂后期开始：细胞周期分化的分子机制

基本信息

批准号：
14571738
负责人：
KUKITA Toshio
金额：
$ 2.24万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

Osteoclasts are multinucleated giant cells and it has been elucidated that mononuclear osteoclast precursors fuse each other to form multinucleated cells. Under the bone microenvironment composed of RANKL and other factors, osteoclastoprogenitors proliferate to differentiate into real osteoclasts, however, it has been ambiguous concerning the exact point of divergence into osteoclast-lineage in cell cycle. Previously we found the osteoclast-specific membrane molecule Kati-antigen expressed on rat osteoclasts. When we examined initiation of osteoclastogenesis using anti-Kati-antigen monoclonal antibody (mAb Kat1) as the tracer of osteoclastogenesis, we found an interesting observation in which Kati-antigen was expressed only in one daughter cells of dividing cells at the postmitotic phase of osteoclast progenitors. Mab Kati also reacts with rat astrocytic cell line RCR-1 cells. If the cell cycle of RCR-1 cells was synchronized to mitosis by treatment with colcemid, numerous RCR-1 cells in mitotic phase expressed Kati-antigen. Morphological analysis revealed that Kati-antigen was expressed only in one daughter cells of dividing cells at the postmitotic phase of RCR-1 cells in a similar pattern as osteoclast progenitors. As it was suggested that Kati-antigen is the receptor molecule determining the differentiation fate of the progenitors, we focused on elucidating the entity of this antigen and obtained data which suggest, that Kat-1 antigen was a related molecule with galectin 3. To separate postmitotic osteoclast progenitors into Kat1-positve cells and Kat1-negative cells was quite difficult in terms of experimental technology, and therefore we could not compare mRNA expression profiles among these two cell fractions. Now we are trying to construct M-phase specific cDNA library by use of RAW-D cells synchronized to M-phase. This study would enable an establishment of novel strategy of regulating bone resorption through targeting osteoclast progenitors in M-phase.

破骨细胞是多核巨细胞，已经阐明了单核破骨细胞前体相互融合以形成多核细胞。在由RANKL和其他因素组成的骨微环境下，破骨质基因生成剂增殖到分化为实际破骨细胞，但对于细胞周期中的骨化性点的确切点向破骨细胞分离，这是模棱两可的。以前，我们发现在大鼠破骨细胞上表达的破骨细胞特异性膜分子kati抗原。当我们使用抗Kati-antigen单克隆抗体（MAB KAT1）作为破骨细胞造成的示踪剂研究了破骨细胞生成的起始时，我们发现了一个有趣的观察结果，其中仅在骨质骨化骨质质量质体的骨膜后分裂细胞中仅在一个分裂细胞的一个子细胞中表达Kati-Antigen。 MAB KATI还与大鼠星形细胞系RCR-1细胞反应。如果将RCR-1细胞的细胞周期通过用Colcemid治疗将RCR-1细胞的细胞周期同步为有丝分裂，则有丝分裂期的许多RCR-1细胞表达了Kati-Atigen。形态学分析表明，Kati-Antigen仅在一个与破骨细胞祖细胞相似的RCR-1细胞的菌落后阶段的一个子细胞中表达。 As it was suggested that Kati-antigen is the receptor molecule determining the differentiation fate of the progenitors, we focused on elucidating the entity of this antigen and obtained data which suggest, that Kat-1 antigen was a related molecule with galectin 3. To separate postmitotic osteoclast progenitors into Kat1-positve cells and Kat1-negative cells was quite difficult in terms of experimental technology,因此，我们无法比较这两个细胞部分之间的mRNA表达谱。现在，我们试图通过使用与M相同步的RAW-D细胞来构建M期特异性cDNA库。这项研究将实现通过靶向M阶段破骨细胞祖细胞来调节骨吸收的新型策略。