Molecular Analysis of PTHrP Receptor in Chondrocytes

为了阐明甲状旁腺激素相关肽(PTHrP)在软骨细胞中的生理作用，有必要研究PTHrP受体介导的信号转导的分子机制，因为PTHrP基因敲除的小鼠会出现软骨发育不全样畸形。在目前的项目中，我们主要集中在受体介导的信号转导和PTHrP在各种软骨疾病中的表达。前者研究了甲状旁腺激素相关肽(PTHrP)在原代培养的大鼠关节软骨细胞中的不同片段对细胞功能的影响；后者则分析了甲状旁腺激素相关肽(PTHrP)在骨关节炎和风湿性关节炎中的病理生理作用。外源性添加hPTHrP(1-34)、hPTHrP(1-141)、hPTHrP(100-114)和hPTH(1-34)对胸腺嘧啶核苷掺入、α(1)型胶原基因表达、细胞内cAMP和[Ca^&lt；2+&Gt；]i水平的影响相似。反义寡核苷酸降低甲状旁腺激素受体mRNA反式…更多的国家明确地抑制了DNA合成。这些数据推测，在外源性添加的hPTH和hPTHrP之间没有显著的差异，另一方面，细胞内的PTHrP除了具有经典的PTH/PTHrP受体介导的功能外，可能还有一种未知的生物学作用(J Endocinkology 150：359-368 1996)。在骨关节炎和风湿性关节炎的组织再生中，PTHrP是调节细胞运动和凋亡的关键细胞因子(BR J Rheumatol 35：1056-1062 1996，J Osteopedic，in Press)。为了进一步扩展基础研究，我们将重点放在细胞因子异常表达导致的软骨细胞逃避生理性再生或凋亡，最终导致基因不稳定和细胞异常增殖的关键事件上。实验设计为体内动物模型，植入PTHrP产生的成骨细胞样细胞，并在细胞周围形成骨基质(Endocine J 43：527-1996)。此外，我们已经将反义PTHrP寡核苷酸疗法应用于产生PTHrP的肿瘤(癌症资源56：77-86,1996)。最后，我们感谢来自这项资助的支持和我们博士后研究员和工作人员的宝贵贡献。较少

To elucidate the physiology of parathyroid-hormone-related peptide (PTHrP) in chondrocytes, it is essential to investigate on the molecular mechanism of PTHrP receptor mediated signal transduction because PTHrP knock-out mice developed achondroplasia like deformity. In the present projects, we have concentrated in the receptor-mediated signal transduction and PTHrP expression of various cartilage disease. In the former, we have studied the effect of various fragments of PTHrP in primary culture of rat articular chondrocytes and function of the cell lines transfected PTHrP.In the later, we have analyzed the pathophysiological role of parathyroid-hormone-related peptide (PTHrP) in osteoarthritis and rheumatic arthritis.The action of exogenously added hPTHrP (1-34), hPTHrP (1-141), hPTHrP (100-114) and hPTH (1-34) on thymidine incorporation, alpha (1) type II collagen gene expression, intracellular cAMP and [Ca^<2+>] i level was similar. Antisense oligonucleotides decreased PTHrP mRNA tra … More nslation specifically inhibited DNA synthesis. These data are speculated that there is no significant difference among exogenously added hPTH and hPTHrP,on the other hand intracellular PTHrP may have a yet unknown biological role, in addition to a classical PTH/PTHrP receptor-mediated function (J Endocrinology 150 : 359-368 1996).In tissue regeneration of osteoarthritis and rheumatic arthritis, PTHrP is a key cytokine regulated the cell motility and apoptosis (Br J Rheumatol 35 : 1056-1062 1996, J Osteopaedic Res, in press). To further extend the basic research, we have focused on the critical events of chondrocytes induced by abnormal expression of cytokines escaping from physiological regeneration or apoptosis, which can eventually induce gene instability and abnormal cell proliferation. The experimental design is in vivo rat animal model which was implanted with PTHrP producing osteoblast like cell and developed bone matrix formation around the cells (Endocrine J 43 : 527-535 1996). Furthermore, we have applied the antisense PTHrP oligonucleotide therapy against PTHrP producing tumor (Cancer Res 56 : 77-86,1996).Finally, we acknowledge a support from this grant and a valuable contribution of our post doc fellows and staffs. Less