长期递增负荷运动中骨髓和胸腺趋化因子CCR9、CCL25的应答性特征

Responsive Characteristics of Chemotactic Factors CCR9/CCL25 in Bone Marrow and Thymus during Long-Term Incremental Exercise

目的:研究对骨髓和胸腺细胞具有归巢作用的趋化因子受体CCR9和配体CCL25在长期递增负荷运动中的应答性特征,探讨长期运动影响T细胞发育的调节机制。方法:将SD大鼠随机分为运动组和对照组,运动组进行递增负荷跑台训练5周,每周6次,每天30 min。第1周运动负荷为10 m·min(-1),第2周为20 m·min(-1),此后每周增加5 m·min(-1),至6周时达40 m·min-1。分别于第0、2、4、6周末,利用ELISA技术测定安静状态、运动后即刻和运动后3 h骨髓和胸腺中CCR9和CCL25表达水平。结果:骨髓和胸腺中的CCR9、CCL25呈现几乎相反的应答性变化。结论:随着递增负荷运动的进程,骨髓中的趋化因子受体CCR9和配体CCL25总体水平越来越高,且越来越难以恢复,表明骨髓归巢因子信号需求越来越强;而胸腺CCR9、CCL25总体水平越来越低,越来越难恢复,表明胸腺微环境紊乱程度越来越高。这应是受长期递增负荷运动影响,T细胞归巢及发育受阻且功能逐步下降的重要机理之一。

Abstract Objectives： It is to observe the responsive characteristics of CCRg/CCL25, the two chemotactic factors in bone marrow and thymus during long-term incremental exercise and to explore the regulative mechanism of T lymphocyte development with long-term exercise. Methods： Sprague-Dawle rats were randomly divided into control and exercise group. Exercise protocol： treadmill exercise, successive 6 weeks, 6 days per week, 30 minutes per day, 10 m·min^-1 in week 1, 20 m ·min^-1 in week 2, with 5 m ·min^-1 increment in the following weeks till it reached 40 m ·min^-1 in the 6^th week. Samples were taken before exercise, at rest, immediately after exercise and 3 hours after exercise, respectively at the end of week 2, 4 and 6. CCR9/CCL25 was tested by ELISA. Results： CCR9/CCL25 in bone marrow and thymus presented almost opposite responsive pattern during 6-week incremental exercise. Conclusions： There is an increasing growth for CCR9/CCL25 level in bone thymus and more difficulty of recovery during the incremental exercise, which means an increasing growth of demands for chemotactic factors in bone marrow. On the other hand, a decreasing growth for CCR9/CCL25 level in thymus and more difficulty of recovery show the increasingly big disorder for thymus micro-environment. It should be one of the important mechanisms for T lymphocyte development impairment and gradually downgrading function with long-term incremental exercise.