Laboratory of Exercise Biochemistry, Department of Physical Education, College of Arts and Physical Education, Dong-A University, 37 Nakdong-daero 550 beon-gil, Hadan-dong, Saha-gu, Busan, 49315, Republic of Korea.
Lipids Health Dis. 2018 Apr 16;17(1):81. doi: 10.1186/s12944-018-0730-8.
The purpose of this study was to determine whether regular exercise training enhances intramuscular triglyceride (IMTG) lipolysis sensitivity during consumption of a continued high-fat diet by exploring changes in biochemical factors activated by IMTG lipolysis.
Male C57BL/6 mice aged 4 weeks were randomly divided into a high-fat diet group (HF) to induce obesity for 6 weeks and a control (CO) group. Thereafter, the HF group was divided into a high-fat diet group (HF) and high-fat diet + training group (HFT). The HFT group was trained on an animal treadmill 40 min/day, 5 days/week for 8 weeks. PKA, Plin5, p-Plin5, CGI-58, ATGL, and HSL were analyzed to investigate IMTG sensitivity by western blotting.
PKA, CGI-58, and HSL protein levels in the HF group were significantly lower than those in the CO group (p < 0.05). However, PKA, CGI-58, and HSL protein levels in the HFT group were significantly higher than those in the HF group, and ATGL and p-Plin5 protein levels as well as the p-Plin5/Plin5 ratio in the HFT group were significantly higher than those in the HF group (p < 0.05). In addition, the HF group showed a significantly higher IMTG volume than the CO and HFT groups (p < 0.05).
These results suggest that in an obese mouse model, 8 weeks of treadmill exercise contributes to decreased IMTG volume by activating lipolysis factors, such as PKA, PLIN5, CGI-58, and lipases. Therefore, regular exercise training may play an important role in obesity treatment by increasing IMTG lipolysis sensitivity.
本研究旨在通过探索内肌甘油三酯（IMTG）脂解敏感性相关生化因子的变化，确定规律运动训练是否会增强持续高脂肪饮食状态下的 IMTG 脂解敏感性。
4 周龄雄性 C57BL/6 小鼠随机分为高脂肪饮食组（HF）以诱导肥胖 6 周，和对照组（CO）。此后，HF 组再分为高脂肪饮食组（HF）和高脂肪饮食+训练组（HFT）。HFT 组在动物跑步机上每天训练 40 分钟，每周 5 天，共 8 周。通过 Western blot 分析蛋白激酶 A（PKA）、Plin5、磷酸化 Plin5（p-Plin5）、甘油三酯脂肪酶（CGI-58）、脂肪酶（ATGL）和激素敏感脂肪酶（HSL），以研究 IMTG 敏感性。
HF 组的 PKA、CGI-58 和 HSL 蛋白水平明显低于 CO 组（p<0.05）。然而，HFT 组的 PKA、CGI-58 和 HSL 蛋白水平明显高于 HF 组，且 HFT 组的 ATGL 和 p-Plin5 蛋白水平以及 p-Plin5/Plin5 比值明显高于 HF 组（p<0.05）。此外，HF 组的 IMTG 体积明显高于 CO 和 HFT 组（p<0.05）。
这些结果表明，在肥胖小鼠模型中，8 周的跑步机运动通过激活 PKA、PLIN5、CGI-58 和脂肪酶等脂解因子，有助于减少 IMTG 体积。因此，规律运动训练可能通过增加 IMTG 脂解敏感性在肥胖治疗中发挥重要作用。
