瘦素在椎体骺软骨细胞软骨内骨化过程中的部位特异性作用研究

Endochondral ossification in the spinal growth plate is the key step for spinal growth and attainment of peak bone mass.Leptin,a key regulator of bone mineral metabolism,serves as a triggering signal for the onset of puberty.The bone structures and development of spine and limb are dofferent. The effect of leptin on the growth of spine is different from that of limb.We also observed that there are significant differences of the expression level of leptin receptor between vertebral and tibial growth plate.The influences of leptin on the primary cultured chondrocytes differentiation of vertebral and tibial growth plate are also different.However,the specific influential mechanisms of leptin on spinal growth has not been reported till now.In the present project, we intend to observe the different time- and dose-dependent effect of leptin on the proliferation and differentiation of spine and limb growth plate at organic and cellular levels. Comparing with the limb growth plate,we plane to study the specific action role of the classic signalling pathways of leptin during proliferation,differentiation and apoptosis for vertebral growth plate;we also intend to study the specific interaction of leptin and Wnt et al.in spinal growth plate.The results of our study are helpful to reveal the specific mechanism of leptin on the spinal growth,and to acknowledge and understand the grwoth,development and maturity of spine.The present researches will set up theoretical foundation for prevision and etiological studies of the spinal developmental disorders.

椎体骺板软骨内骨化是脊柱生长和骨量达到峰值的关键步骤,瘦素是青春期的准入因子,是骨代谢的重要调解者。椎体和长骨的骨结构不同,发育形式亦不同。瘦素对椎体生长的影响不同于长骨。我们也发现青春期生长发育高峰,大鼠椎体和胫骨骺板内瘦素受体表达水平有显著差异，瘦素对原代培养的椎体和胫骨骺板软骨细胞分化刺激作用不同。但瘦素对椎体骺板生长代谢的特异性影响机制研究还未有报道。我们拟在器官和细胞水平观察瘦素对椎体和长骨骺板增生和分化不同影响的时间和浓度依赖效应；探讨瘦素的经典信号通路在椎体骺板软骨细胞增生、分化和凋亡过程中,相对长骨的,特异性作用规律；研究瘦素在椎体内同软骨内骨化中的重要因子Wnt等之间可能的，不同于长骨的，相互作用机制。研究结果将对瘦素对椎体生长影响的特异性机制有所揭示,有助于我们更好地认识和理解脊柱的生长、发育和成熟,同时为脊柱发育异常等相关疾病的防治和病因学研究奠定理论基础。

椎体骺板软骨内骨化是脊柱生长和骨量达到峰值的关键步骤,瘦素是青春期的准入因子,是骨代谢的重要调解者。椎体和长骨的骨结构不同,发育形式亦不同。本课题意在探究瘦素对椎体及长骨骺板软骨细胞的部位差异性研究。本课题在器官和细胞水平研究瘦素对椎体和长骨骺板增生、分化和凋亡的特异性影响,检测骺板软骨细胞增生、肥大、分化以及凋亡的相关标记物, 重点观察瘦素刺激的时间和浓度依赖效应的部位特异性，并观察不同的通路在椎体及长骨骺板软骨细胞发育过程中的不同作用。课题组通过研究发现，瘦素导致长骨及椎体骨组织和骨细胞形态不同，瘦素促进长骨骺板软骨细胞的增殖，但是抑制椎体骺板软骨细胞的增殖，瘦素能够刺激椎体生长板细胞的凋亡，并且刺激具有浓度依赖效应，而长骨生长板中凋亡反而减少，并发现一定浓度的瘦素促进长骨骺板软骨细胞增生和分化，而抑制椎体骺板软骨细胞的增生和分化，并在此基础上发现了瘦素对脊柱和长骨骺板软骨细胞分化信号通路的差异性调节。通过本课题，我们揭示了瘦素在骨代谢中的重要调节作用, 通过本课题的研究，丰富了脊柱生长发育和成熟的理论, 为脊柱发育异常等相关疾病的病因学研究奠定理论基础, 有助于为生长发育期的脊柱健康提供有效的指导性建议。