Unit of Internal Medicine, Angiology and Arteriosclerosis Diseases, Department of Clinical and Experimental Medicine, University of Perugia, Hospital "Santa Maria della Misericordia", Piazzale Menghini, 1-06129 Perugia, Italy.
Osteoporos Int. 2010 Feb;21(2):297-306. doi: 10.1007/s00198-009-0968-0. Epub 2009 May 30.
The role of circulating osteoprogenitor cells in postmenopausal osteoporosis is unknown. We found that alkaline-phosphatase-positive (AP+) cells are the lacking cells in osteoporosis, whose reduction is related to bone loss. Conversely, the increased number of alkaline phosphatase/CD34-positive cells may reflect the reactive bone marrow contribution to bone formation.
Circulating osteoprogenitor cells mineralize in vitro and in vivo. Loss of osteogenic cells may account for bone loss in osteoporosis. We studied whether there is an association between the number of circulating osteoprogenitor cells and bone mineral density (BMD) in postmenopausal women with and without osteoporosis.
The number of circulating AP+, osteocalcin-positive (OCN+), AP+/CD34+, and OCN+/CD34+ cells was quantified in 54 postmenopausal osteoporotic women and 36 age-matched nonosteoporotic controls.
The number of AP+ cells was lower in osteoporotic women than in controls (127 +/- 16 vs 234 +/- 23 per microliter; p < 0.001); higher levels of AP+/CD34+, OCN+, and OCN+/CD34+ cells were found in osteoporotic than controls (p < 0.01 for all). The number of AP+ cells was correlated with lumbar BMD (rho = 0.29; p = 0.008) and proximal femur BMD (rho = 0.31; p = 0.005) whereas inverse correlations were found between AP+/CD34+ cells, OCN+, OCN+/CD34+, and BMD. Reduced AP+ cells and increased AP+/CD34 +, OCN+, and OCN+/CD34+ cells were predictors of low BMD, independent of traditional risk factors for osteoporosis.
In postmenopausal osteoporotic women, a reduced number of circulating AP+ cells and increased levels of AP+/CD34+, OCN+, and OCN+/CD34+ cells are associated with reduced bone mineral density, the interpretation of such a cellular imbalance needing exploration.
循环成骨细胞在绝经后骨质疏松症中的作用尚不清楚。我们发现碱性磷酸酶阳性（AP+）细胞是骨质疏松症中缺失的细胞，其减少与骨丢失有关。相反，碱性磷酸酶/CD34 阳性细胞数量的增加可能反映了反应性骨髓对骨形成的贡献。
循环成骨细胞在体外和体内矿化。成骨细胞的丢失可能导致骨质疏松症的骨丢失。我们研究了绝经后骨质疏松症妇女和非骨质疏松症妇女的循环成骨细胞数量与骨密度（BMD）之间是否存在关联。
在 54 例绝经后骨质疏松症妇女和 36 例年龄匹配的非骨质疏松症对照者中，定量检测循环 AP+、骨钙素阳性（OCN+）、AP+/CD34+和 OCN+/CD34+细胞的数量。
骨质疏松症妇女的 AP+细胞数低于对照组（127±16 与 234±23 个/微升；p<0.001）；骨质疏松症组的 AP+/CD34+、OCN+和 OCN+/CD34+细胞水平较高（所有 p<0.01）。AP+细胞数与腰椎 BMD（rho=0.29；p=0.008）和股骨近端 BMD（rho=0.31；p=0.005）呈正相关，而 AP+/CD34+细胞与 BMD 呈负相关。AP+细胞减少和 AP+/CD34+、OCN+、OCN+/CD34+细胞增加是 BMD 降低的预测因素，独立于骨质疏松症的传统危险因素。
在绝经后骨质疏松症妇女中，循环 AP+细胞数量减少和 AP+/CD34+、OCN+、OCN+/CD34+细胞水平升高与骨矿物质密度降低相关，这种细胞失衡的解释需要进一步研究。
