CaSR介导Ca2+促进塔里木马鹿鹿茸生长及骨化的研究

Tarim Cervus Elaphus inhabit in desert landscapes, and its velvet antler yields are higher than that of other deers. In antler growth phase, calcium is massively needed and the concentration of the element drastically change in deer antlers. However,it still needs further study in the regulation of calcium during antler growth phase. Calcium-sensing receptor (CaSR) play an important role in regulating the bone calcium homeostasis. Because our study team detected the different expression of CaSR in antlers of Tarim Cervus Elaphus during antler growth phase, we hypothesize that CaSR could mediated the change of the antler calcium and improved antlers growth and ossification during the antler growth phase in Tarim Cervus Elaphus. According to the clues, Real-time PCR, Western Blot, ELISA, Laser scanning confocal microscope (LSCM), tissue sections and etc. will be used to examined expression of CaSR and the intra/extracellular variations of Ca2+ in different regions and phase of the velvet antler, to reveal the interconnection between CaSR and Ca2+,clarify the mechnism of CaSR-mediated the antler Ca2+ signal transduction in Tarim Cervus Elaphus. In the present project, it is to illustrate the mechnism of CaSR-mediated Ca2+ regulting the velvet antlers growth and ossification, to provide scientific basis for further pefecting the mechanism of antler ossification.

塔里木马鹿世代栖息于荒漠景观，产茸量高。Ca是茸生长过程中需求量最大的矿物质元素，生茸期鹿茸中Ca2+含量变化剧烈，但生茸期Ca2+调控的机制，有待进一步完善。 CaSR在维持钙稳态中发挥重要作用。课题组在前期研究中发现塔里木马鹿在鹿茸生长不同时期存在CaSR的差异表达，故推测CaSR参与介导了生茸期鹿茸中Ca2+的变化，以促进鹿茸的生长及骨化。 依此线索，本项目以塔里木马鹿为对象，通过Real-time PCR、Western Blot、ELISA、激光共聚焦、组织切片等方法，检测生茸不同时期、茸不同区域CaSR的表达量及Ca2+在细胞内外的变化规律；理清CaSR表达量与Ca2+变化之间的关系；阐明生茸不同时期CaSR介导Ca2+变化的信号转导机制。旨在通过上述研究，探索生茸期鹿茸中CaSR通过介导Ca2+，促进鹿茸生长及骨化的原理，为进一步完善鹿茸骨化机理提供依据。

塔里木马鹿栖息于沙漠荒地，产容量高。鹿茸作为鹿科动物的附属器官，在秦汉时期,我国就将其作为一种神奇的动物药材并对其临床疗效加以探索；近年来，中、日、韩等国学者对鹿茸活性成分、药理作用和临床疗效进行了系统的研究，使其成了家喻户晓的名贵中药。然而，鹿茸的药用价值与其骨化程度成反相关关系。本研究发现鹿茸的骨化与钙敏感受体及其相关因子，血清相关激素等因素具有密切关系。本研究明确了塔里木马鹿鹿茸生长规律，鹿茸中钙的沉积规律；鹿茸的组织结构；血清激素与鹿茸骨化的相关关系；钙敏感受体及其相关因子与鹿茸细胞内钙离子浓度的相关关系。不同年龄的马鹿鹿茸脱盘的时间不同，青年组马鹿脱盘时间最晚，骨化也最晚；老年组马鹿脱盘时间最早，骨化时间也最早。鹿茸组织分为表皮层，真皮层，间充质层，前软骨层，软骨层，骨松质层等结构。血清中ADG、PTH、CT、BALP、BGP及BSP与鹿茸的钙化密切相关。鹿茸组织中，鹿茸上段CaSR的表达显著高于中、下段；鹿茸下段CaSR的表达最低。CaSR、BSP、Runx2在鹿茸前软骨细胞中的表达高于间充质细胞与软骨细胞。本研究结果表明鹿茸的骨化与多种因素相关，暗示我们如果调控这些因素可能会影响鹿茸的骨化时间与骨化程度，提高鹿茸的药用价值。