SHIP1 REGULATION OF DAP12 IN OSTEOCLAST DEVELOPMENT AND FUNCTION

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 破骨细胞在自身免疫性疾病状态如类风湿性关节炎中被不适当地激活。虽然通过RANKL和MCSF的信号是破骨细胞分化所必需的，但其他受体的调节作用尚不明确。 我们专注于TREM 2，一种在破骨细胞中发现的免疫受体。TREM 2与DAP 12结合，DAP 12是一种含有信号转导衔接蛋白的ITAM（基于免疫受体酪氨酸的激活基序）。 TREM 2/DAP 12信号传导是破骨细胞成熟所需的，并在体外激活破骨细胞融合和迁移。 细胞内磷酸酶负调节造血细胞中的许多ITAM衔接蛋白。因此，我们研究了磷酸酶抑制破骨细胞中TREM 2/DAP 12信号的作用。我们的数据表明，含SH 2结构域的5'肌醇磷酸酶（SHIP 1）和DAP 12在破骨细胞裂解物中相关。SHIP 1无效的前破骨细胞在破骨细胞生成期间对TREM 2/DAP 12信号传导具有高响应性，表明SHIP 1在抑制该途径中具有功能性作用。这些数据表明，SHIP 1磷酸酶调节破骨细胞中的DAP 12信号传导。 使用来自C57 B16和SHIP 1-/-小鼠的原代鼠破骨细胞培养物的体外破骨细胞生成测定，我们确定了SHIP 1在调节DAP 12信号中的作用。我们正在绘制DAP 12和SHIP 1之间的蛋白质-蛋白质相互作用。我们正在确定SHIP 1是否调节DAP 12的激活，以响应其他刺激，包括M-CSF和骨桥蛋白。这些研究将揭示SHIP 1调节DAP 12信号传导的功能性质以及破骨细胞中这种调节所需的重要蛋白质结构域，并可能导致抑制破骨细胞分化或活化的新策略。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Osteoclasts are inappropriately activated in autoimmune disease states such as rheumatoid arthritis. While signals through RANKL and MCSF are required for osteoclast differentiation, regulation by other receptors is less well defined. We have focused on TREM2, an immune receptor found in osteoclasts. TREM2 associates with DAP12, an ITAM (immunoreceptor tyrosine-based activation motif) containing signaling adapter protein. TREM2/DAP12 signaling is required for osteoclast maturation and activates osteoclast fusion and migration in vitro. Intracellular phosphatases negatively regulate many ITAM adapter proteins in hematopoietic cells. As such, we investigated the role of phosphatases inhibiting TREM2/DAP12 signals in osteoclasts. Our data shows that SH2 domain-containing 5' inositol phosphatase (SHIP1) and DAP12 are associated in osteoclast cell lysates. SHIP1 null preosteoclasts are hyper-responsive to TREM2/DAP12 signaling during osteoclastogenesis indicating that SHIP1 has a functional role in inhibiting this pathway. These data suggest that SHIP1 phosphatase regulates DAP12 signaling in osteoclasts. Using in vitro osteoclastogenesis assays from primary murine osteoclast cultures from C57Bl6 and SHIP1-/- mice we are determining the role of SHIP1 in regulating DAP12 signals. We are mapping the protein-protein interactions between DAP12 and SHIP1. We are determining whether SHIP1 regulates DAP12 activation in response to other stimuli including M-CSF and osteopontin. These studies will reveal the functional nature of SHIP1 regulation of DAP12 signaling as well as the important protein domains required for this regulation in osteoclasts and might lead to novel strategies to inhibit osteoclast differentiation or activation.