Objective: To investigate the effects of 4-week electroacupuncture intervention on "Browning" of white fat in rats, and to explore its molecular mechanisms. Methods: Twenty-four 8-week-old male SD rats were randomly divided into sedentary group (Sed), aerobic exercise group (Exe) and electroacupuncture group (ElA), 8 rats in each group. Exe group used 65% Max oxygen uptake intensity treadmill exercise, 1 h/d,6 d/w, while the ElA group used electric acupuncture to stimulate "zusanli" and "tianshu" points, 20 min/d,6 d/w, and the weight of rats was recorded every week. After 4 weeks of intervention, blood samples were collected from the apex and abdominal aorta. The wet weight of scapular fat and perirenal fat of rats was detected and the body fat and the serum levels of Irisin were determined. What's more, the expressions of adenosine 5'-monophosphate activated protein kinase-α (AMPKα), phosphorylation of adenosine 5'-monophosphate activated protein kinase-α (p-AMPKα), peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α), fibronectin type III domain containing 5 (FNDC5) and uncoupling protein (UCP1) and brown adipose tissue lipid droplets in rats were detected. Results: Compared with the Sed group, the weight gain of rats in the Exe and ElA groups was decreased significantly from the second week. After 4 weeks, the body weight and body fat of the Exe and ElA groups were decreased significantly (P＜0.01), while there was no significant difference between the Exe and ElA groups (P＞0.05). ②After 4 weeks of intervention, the white fat wet weight of ElA group and Exe group was significantly was reduced (P＜0.05 or P＜0.01). ③The serum levels of Irisin in Exe and ElA groups were significantly increased (P＜0.05), and the expressions of p-AMPKα/AMPKα, PGC-1α, FNDC5 in the gastrocnemius and the expressions of UCP1 in white fat and brown adipose tissue of Exe and ElA groups were increased (P＜0.05). ④The area of lipid droplets in white and brown adipose tissue of Exe and ElA groups was significantly reduced (P＜ 0.01). Conclusion: 4 weeks of electroacupuncture intervention can effectively control the weight of rats and induce "browning" of white fat, and its effect was similar to aerobic exercise, which may be release Irisin through the AMPKα-PGC-1α-FNDC5-Irisin signaling pathway, and then "crosstalk" with adipose tissue, up-regulate the expression of UCP1, and induce "browning" of white adipose tissue.
目的: 以有氧运动作为参照,观察4周电针干预对大鼠白色脂肪“棕色化”的影响,探究其可能的分子机制。方法: 将24只8周龄雄性SD大鼠随机分为安静对照组(Sed组)、有氧运动组(Exe组)、电针组(ElA组),每组8只,每组分别干预4周。Exe组采用65%最大摄氧量强度跑台运动,1 h/d,每周6 d。ElA组采用电针刺激“足三里”和“天枢”穴,20 min/d,每周6 d,每周记录大鼠体重。4周干预结束后,心尖和腹主动脉取血处死,分离双侧腓肠肌、肾周和附睾周围白色脂肪组织并称湿重,检测大鼠体脂含量和血清Irisin的水平,检测大鼠腓肠肌中AMPKα、p-AMPKα、PGC-1α、FNDC5和脂肪组织中UCP1蛋白的表达,检测大鼠棕色脂肪组织脂滴的形态。结果: ①与Sed组相比,从第2周开始,Exe、ElA组大鼠体重的增长明显降低,4周后Exe、ElA组大鼠体重和体脂含量明显降低(P＜0.01),而Exe、ElA组之间未见显著差异(P＞0.05)。②4周干预后,ElA组和Exe组大鼠白色脂肪湿重均明显降低(P＜0.05或P＜0.01)。③Exe和ElA组大鼠的血清Irisin水平明显升高(P＜0.05),Exe、ElA组腓肠肌p-AMPKα/AMPKα、PGC-1α、FNDC5蛋白表达和白色脂肪、棕色脂肪组织中UCP1蛋白表达均明显升高(P＜0.05)。④Exe、ElA组大鼠白色和棕色脂肪组织中脂滴面积明显降低(P＜0.01)。结论: 4周的电针干预,可有效控制大鼠体重,诱导白色脂肪“棕色化”,具有与4周有氧运动近似的减脂效果,其可能是通过AMPKα-PGC-1α-FNDC5-Irisin信号通路,释放Irisin,进而与脂肪组织“crosstalk”,上调UCP1的表达,诱导白色脂肪组织“棕色化”。.
Keywords: aerobic exercise; brown fat; electroacupuncture; muscle factor; white fat.