Barry Julianne C, Simtchouk Svetlana, Durrer Cody, Jung Mary E, Little Jonathan P
1School of Health and Exercise Science, University of British Columbia, Kelowna, BC, CANADA; and 2Irving K. Barber School of Arts and Science, Biology, University of British Columbia, Kelowna, BC, CANADA.
Med Sci Sports Exerc. 2017 Aug;49(8):1631-1640. doi: 10.1249/MSS.0000000000001261.
Obesity is characterized by chronic low-grade inflammation driven by activation and tissue infiltration of circulating leukocytes. Although exercise has anti-inflammatory effects, the impact of exercise on mediators of leukocyte migration is unclear.
To determine the impact of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT), in the absence of weight/fat loss, on circulating chemokines and leukocyte chemokine receptors.
Thirty-seven inactive obese adults were randomized to 2 wk (10 sessions) of HIIT or MICT with fasting blood samples collected before and after training. Plasma concentration of C-C motif chemokine ligand 2 (CCL2; also known as monocyte chemoattractant protein-1), CCL3 (also known as macrophage inflammatory protein-1alpha), and C-X-C motif ligand 8 (CXCL8; also known as interleukin-8) were determined and the chemokine receptors CCR2, CCR5, and CXCR2 were measured on monocytes, neutrophils, and T cells.
MICT reduced the percentage of monocytes positive for CCR2 and reduced surface protein expression of CXCR2 on monocytes (both P < 0.05), whereas HIIT increased CCR5 surface protein expression and percentage CCR5 positive monocytes and neutrophils (all P < 0.05) along with increasing the percentage of T cells that were positive for CCR5 (P < 0.05). There were no significant changes in circulating chemokines, percent body fat or visceral adipose tissue.
Exercise, in the absence of weight/fat loss and without changes in circulating chemokines, has direct effects on leukocytes in obese adults with HIIT and MICT resulting in different responses. MICT may reduce monocyte migration potential through downregulation of CCR2 and CXCR2, whereas HIIT may increase potential for CCR5-mediated monocyte, neutrophil, and T-cell infiltration. The impact of different exercise protocols on leukocyte trafficking to tissues in obesity warrants further research.
肥胖的特征是由循环白细胞的激活和组织浸润驱动的慢性低度炎症。尽管运动具有抗炎作用，但运动对白细胞迁移介质的影响尚不清楚。
在不减轻体重/脂肪的情况下，确定高强度间歇训练（HIIT）与中等强度持续训练（MICT）对循环趋化因子和白细胞趋化因子受体的影响。
37名不运动的肥胖成年人被随机分为两组，分别进行为期2周（10节）的HIIT或MICT训练，训练前后采集空腹血样。测定血浆中C-C基序趋化因子配体2（CCL2；也称为单核细胞趋化蛋白-1）、CCL3（也称为巨噬细胞炎性蛋白-1α）和C-X-C基序配体8（CXCL8；也称为白细胞介素-8）的浓度，并检测单核细胞、中性粒细胞和T细胞上的趋化因子受体CCR2、CCR5和CXCR2。
MICT降低了CCR2阳性单核细胞的百分比，并降低了单核细胞上CXCR2的表面蛋白表达（两者P<0.05），而HIIT增加了CCR5的表面蛋白表达以及CCR5阳性单核细胞和中性粒细胞的百分比（均P<0.05），同时增加了CCR5阳性T细胞的百分比（P<0.05）。循环趋化因子、体脂百分比或内脏脂肪组织无显著变化。
在不减轻体重/脂肪且循环趋化因子无变化的情况下，运动对肥胖成年人的白细胞有直接影响，HIIT和MICT导致不同的反应。MICT可能通过下调CCR2和CXCR2来降低单核细胞迁移潜能，而HIIT可能增加CCR5介导的单核细胞、中性粒细胞和T细胞浸润的潜能。不同运动方案对肥胖状态下白细胞向组织内迁移的影响值得进一步研究。
