美国最新一期《细胞》月刊发表哥伦比亚大学的一份研究报告指出,男性的生育能力可能与骨骼有关。
研究人员在老鼠身上进行的实验表明,骨骼通过释放一种名为骨钙素的荷尔蒙,起到调节生育能力的作用。这一发现可能是在治疗不育症方面取得的重大进展。
之前关于骨骼与生殖系统之间的相互作用的研究仅集中在生殖腺对骨质的影响上。研究项目负责人杰勒德·卡尔桑蒂说:“由于两个人体器官之间的沟通很少是单向进行的,因此生殖腺对骨骼产生影响的事实表明,可能也会存在反向的作用。”
卡尔桑蒂和他的团队注意到,实验室里的雄性实验鼠中,骨骼不能产生骨钙素的老鼠产仔量也少。研究人员发现,骨钙素能够增加睾丸激素的生成量,睾丸激素是控制男性生育能力的荷尔蒙。在注射了骨钙素之后,这些雄性老鼠体内的睾丸激素水平也有所提高。
但当骨钙素减少时,睾丸激素也随之减少,导致精子量减少。缺乏骨钙素的雄性老鼠与正常的雌性老鼠交配后,生育的胎数是正常雄性老鼠的一半,每一胎的幼仔数量也较少。
鉴于老鼠和人类荷尔蒙之间存在的其他相似性,卡尔桑蒂希望能在人的身上也证实类似情况的存在。如果骨钙素同样能够促进人体睾丸激素的释放,那么骨钙素水平低就可能是不育男性睾丸激素水平过低的原因。
但科学家并没有发现骨骼状况影响女性生育能力的证据。(生物谷Bioon.com)
生物谷推荐原文出处:
Cell doi:10.1016/j.cell.2011.02.004
Endocrine Regulation of Male Fertility by the Skeleton
Franck Oury, Grzegorz Sumara, Olga Sumara, Mathieu Ferron, Haixin Chang, Charles E. Smith, Louis Hermo, Susan Suarez, Bryan L. Roth, Patricia Ducy, Gerard Karsenty
Highlights
Bone regulates male fertility
Osteoblast-derived osteocalcin enhances testosterone production by Leydig cells
Osteocalcin signals through a G protein-coupled receptor, Gprc6a, in Leydig cells
Summary
Interactions between bone and the reproductive system have until now been thought to be limited to the regulation of bone remodeling by the gonads. We now show that, in males, bone acts as a regulator of fertility. Using coculture assays, we demonstrate that osteoblasts are able to induce testosterone production by the testes, though they fail to influence estrogen production by the ovaries. Analyses of cell-specific loss- and gain-of-function models reveal that the osteoblast-derived hormone osteocalcin performs this endocrine function. By binding to a G protein-coupled receptor expressed in the Leydig cells of the testes, osteocalcin regulates in a CREB-dependent manner the expression of enzymes that is required for testosterone synthesis, promoting germ cell survival. This study expands the physiological repertoire of osteocalcin and provides the first evidence that the skeleton is an endocrine regulator of reproduction.