PI3K/AKT调控骨细胞Cx43表达及磷酸化在激素性股骨头坏死中的机制研究

The role of osteocytes in the pathogenesis of glucocorticoid induced osteonecrosis of the femoral head (ONFH) has been becoming a new direction. Cx43 protein plays an important role in osteocyte survival, mechanical stress perception and intercellular signal transduction. Our previous studies found that dexamethasone can regulate the expression of Cx43 phosphorylation in osteocytes through PI3K/AKT signaling pathway, so we further elucidate the specific mechanisms of Cx43 phosphorylation in glucocorticoid induced osteonecrosis..In vitro experiment,the project aims to clarify the effects of different dosages of dexamethasone on the Cx43 expression and phosphorylation of mouse MLO-Y4 cell and the following stress transduction and its molecular mechanism. With cell co-culture technique and fluid shear stress experimental system, we will investigate the PI3K/AKT pathway in the regulation of osteocyte Cx43 phosphorylation and the influence on its activity and function, as well as the connected corresponding cells (osteoblasts, osteoclasts and the endothelial cells); In vivo experiment, using new two-photon imaging technology, we will observe the changes of osteocyte morphology related to the osteocyte Cx43 expression and the related function. We set up a steroid ONFH rabbit model, and regulate the expression and phosphorylation of osteocyte Cx43 through the activation of the PI3K/AKT pathway, thereafter we investigate the role of this regulation in the prevention and repair of early stage steroid induced ONFH, which would provide a new insight for the treatment of this disease.

骨细胞在激素性股骨头坏死（ONFH）发病机制的作用成为国内外新的研究方向，骨细胞Cx43蛋白对其存活、机械应力感受和细胞间信号传导具有重要作用。我们前期研究发现激素通过PI3K/AKT信号通路调控骨细胞Cx43表达及磷酸化，拟进一步阐明其在激素性ONFH中作用机制。.本项目体外研究不同剂量激素对小鼠MLO-Y4细胞Cx43表达、应力转导影响及其分子机制，通过细胞共培养体系和流体剪切应力实验系统，阐明PI3K/AKT通路调控骨细胞Cx43磷酸化对其自身活性和功能的影响，以及对效应细胞（成骨细胞、破骨细胞和内皮细胞）功能的作用机制；体内采用双光子成像新技术，实时动态观察激素作用下Cx43表达及磷酸化对骨细胞形态（树突微管）和功能的影响；建立激素性ONFH大白兔模型，研究激活PI3K/AKT通路调控Cx43磷酸化对激素性ONFH的预防和修复作用，探索一种新的治疗靶点。

骨细胞在激素性股骨头坏死（ONFH）发病机制的作用成为国内外新的研究方向，骨细胞Cx43蛋白对其存活、机械应力感受和细胞间信号传导具有重要作用。我们的研究发现激素通过 PI3K/AKT信号通路调控骨细胞Cx43表达及磷酸化，并进一步阐明其在激素性ONFH中作用机制。本项目体外研究不同剂量激素对小鼠MLO-Y4细胞Cx43表达、应力转导影响及其分子机制，通过细胞共培养体系和流体剪切应力实验系统，阐明了PI3K/AKT通路调控骨细胞Cx43磷酸化对其自身活性和功能的影响，以及对效应细胞（成骨细胞、破骨细胞和内皮细胞）功能的作用机制；体内采用双光子成像新技术，实时动态观察激素作用下Cx43表达及磷酸化对骨细胞形态（树突微管）和功能的影响；建立激素性ONFH大白兔模型，研究激活PI3K/AKT通路调控Cx43磷酸化对激素性ONFH的预防和修复作用，探索一种新的治疗靶点。