Institut National de la Santé et de la Recherche Médicale, Lyon, France.
Calcif Tissue Int. 2010 Oct;87(4):341-50. doi: 10.1007/s00223-010-9391-y. Epub 2010 Jun 22.
Periostin is a gamma-carboxyglutamic acid protein preferentially expressed in periosteum and bone mesenchymal stem cells. Lack of a precise assay for measuring circulating levels impairs the investigation of its biological significance. We developed a new ELISA and studied changes of periostin levels both locally at the bone site and systemically in circulating blood during growth and after bisphosphonate-induced inhibition of bone remodeling in the mouse. The ELISA we developed is based on an affinity-purified polyclonal antibody that was raised against the C-terminal sequence of mouse periostin. Reproducibility, repeatability, precision, and accuracy tests met standards of acceptance. Serum periostin and levels of the bone turnover markers osteocalcin, PINP, CTX-I, and TRAP5b were measured in (1) 4-, 6-, 8-, 10-, and 12-week-old wild-type female Balb/c mice and (2) adult ovariectomized female Balb/c mice treated with zoledronic acid or vehicle. Serum periostin decreased during growth and stabilized from 8 weeks and older, its levels correlating with bone turnover markers. Immunohistochemistry in bones from different growth stages showed that periostin localized specifically at the sites of endochondral and intramembranous ossification, especially at the periosteal envelopes. Zoledronic acid induced a marked decrease in bone remodeling markers but did not alter serum periostin levels or periostin immunostaining pattern. The novel ELISA is highly specific and allows accurate and precise measurements of serum periostin levels in mice.
骨膜蛋白是一种γ-羧基谷氨酸蛋白，主要在骨膜和骨间充质干细胞中表达。由于缺乏精确的检测方法来测量其循环水平，因此限制了对其生物学意义的研究。我们开发了一种新的 ELISA 方法，并在小鼠中研究了生长过程中以及双膦酸盐抑制骨重塑后局部骨部位和循环血液中骨膜蛋白水平的变化。我们开发的 ELISA 基于针对小鼠骨膜蛋白 C 末端序列的亲和纯化多克隆抗体。重复性、再现性、精密度和准确度测试均符合可接受标准。在（1）4 周、6 周、8 周、10 周和 12 周龄的野生型雌性 Balb/c 小鼠和（2）成年去卵巢雌性 Balb/c 小鼠中，我们测量了血清骨膜蛋白和骨转换标志物骨钙素、PINP、CTX-I 和 TRAP5b 的水平，并对其进行了研究。唑来膦酸或载体处理。血清骨膜蛋白在生长过程中下降，并在 8 周龄及以上稳定，其水平与骨转换标志物相关。来自不同生长阶段的骨骼免疫组织化学显示，骨膜蛋白特异性定位于软骨内和膜内成骨部位，尤其是在骨膜包被处。唑来膦酸诱导骨重塑标志物明显减少，但不改变血清骨膜蛋白水平或骨膜蛋白免疫染色模式。新型 ELISA 特异性高，可准确、精确地测量小鼠血清骨膜蛋白水平。
