调节性T细胞与老年性骨质疏松的关系

The Relationship of Regulatory T Cells and Senile Osteoporosis

目的检测不同年龄组雄性SD大鼠血调节性T细胞（Treg）数量占CD4＋T细胞百分比,了解Treg细胞对老年性骨质疏松症的影响.方法选取6-8周龄、6月龄、12月龄、24月龄雄性SD大鼠每组各10只作为研究对象,采用双能X线吸收仪（DEXA）检测大鼠股骨、脊柱、骨盆、全身的骨密度;大鼠心脏采血,采用CD25＋联合Fox P3＋表达来描述Treg细胞,流式细胞仪测定血Treg数量占CD4＋T细胞的百分比.结果 （1）6-8周龄组、6月龄组、12月龄组、24月龄组Treg数量不同,差异有统计学意义（P〈0.01）.6-8周龄组Treg数量百分比低于6月龄组、12月龄组、24月龄组,差异有统计学意义（P〈0.01）;6月龄组Treg数量百分比低于12月龄组、24月龄组（P〈0.05）;24月龄组Treg数量百分比低于12月龄组比较,但差异无统计学意义（P〉0.05）.（2）Treg数量占CD4＋T细胞百分比与股骨、脊柱、骨盆、全身骨密度值均成正相关,差异均有统计学意义（P〈0.01）.结论 （1）6-8周龄组、6月龄组、12月龄组、24月龄组Treg数量占CD4＋T细胞百分比不同,6-8周龄时最低,6月龄时开始升高,12月龄时达到最高值,24月龄时出现下降,提示不同年龄组大鼠Treg数量占CD4＋T细胞有明显差异（P〈0.05）.（2）Treg数量占CD4＋T细胞百分比与检测部位骨密度值呈正相关性,提示随着Treg数量百分比的增高,骨吸收减少,骨密度值升高,随着Treg数量百分比的降低,骨密度降低,鉴于随着年龄的增长,Treg数量出现下降,推测外源性注射Treg可抑制破骨细胞性骨吸收,可成为治疗老年性骨质疏松的新方向.

Objective To understand the effect of regulatory T cells on senile osteoporosis by measuring the percentage of regulatory T cells in CD4＋T cells in different age groups of male SD rats. Me thods Sprague- Dawley male rats which was 6- 8 weeks,6 months,12 months,24 months old were selected as subjects. There were 10 rats in each group. We detected bone mineral density of femur, spine, pelvis, whole- body of rats by dual- energy X- ray absorptiometry. We collected blood samples from the heart, used CD25/forkhead box P3 double- positive to describe regulatory T cells and then measured the percentage of regulatory T cells in CD4＋T cells by flow cytometry.Re s ults（1） The percentage of regulatory T cells in CD4＋T cells in 6- 8 weeks,6 months,12 months,24 months old male rats groups were not the same, the difference was statistically significant（P=0.000）. The percentage of regulatory T cells in CD4＋T cells of 6- 8weeks old groups was lower than 6 months, 12 months, 24 months old groups, the difference was statistically significant（P =0.000）. The percentage of regulatory T cells in CD4＋T cells of 6 months old groups was lower than 12 months, 24 months old groups, the difference was statistically significant（P〈0.05）. The percentage of regulatory T cells in CD4＋T cells of 24 months old groups was lower than12 months, but there was no significant difference（P〈0.05）.（2） There was a positively correlation between the percentage of regulatory T cells in CD4＋T cells and bone mineral density of femur, spine, pelvis, whole- body.Conclus ions（1） The percentage of regulatory T cells in CD4＋T cells in four groups are not the same,the lowest at 6- 8 weeks of age,by 6 months,there is an increase and when 12 months increase to a maximum then decrease at24 months of age, indicating that the percentage of regulatory T cells in CD4＋T cells in different age groups are significantly different.（2） There is a positive correlation between the percentage of regulatory T cells in CD4＋T cells and bone mineral density of femur,spine,pelvis,whole- body,indicating that because of the bone resorption reducing with the percentage of regulatory T cells increasing,the values of bone mineral density raising,when the percentage of regulatory T cells decreasing, the values of bone mineral density declining. In view of the number of regulatory T cells declining with aging,suggesting that exogenous injection of regulatory T cells may inhibit the bone resorption by osteoclast,which may become the new direction of senile osteoporosis treatment.