Effects of different intensities of exercises on BNIP3-mediated mitophagy
in skeletal muscle

doi:10.3969/j.issn.2095-4344.1920

Abstract

Abstract:

BACKGROUND: Different intensities of exercises make different effects on human body, and the changes of skeletal muscle after exercise remain unclear. Physical change of human body during exercise is a hotspot.

OBJECTIVE: To investigate the effect of different intensities of exercises on the mass of rat skeletal muscle, and the role of BNIP3-mediated mitophagy in maintaining skeletal muscle mass.

METHODS: The study was approved by the Laboratory Animal Ethical Committee of Beijing Sport University. Twenty-four healthy male Sprague-Dawley rats aged 8 weeks were randomly divided into three groups: control, moderate-intensity exercise (5°, 15 m/min, 1 hour, 60% VO_2max) and high-intensity exercise (5°, 35 m/min, 20 minutes, 85% VO_2max) groups (n=8/group), 6 times weekly. The rat soleus and gastrocnemius were removed to measure the wet weights. The cross-sectional area of muscle fiber was detected by immunofluorescence. The protein expression levels of BNIP3, p62 and LC3 in the soleus and gastrocnemius were detected by western blot assay.

RESULTS AND CONCLUSION: (1) The wet weight of gastrocnemius in the exercise groups was significantly lower than that in the control group (P < 0.01). (2) The cross-sectional area of gastrocnemius fiber in the exercise groups was significantly less than that in the control group (P < 0.01), and the cross-sectional area of soleus fiber in the exercise groups was significantly more than that in the control group (P < 0.01). (3) The moderate-intensity exercise induced increased mitophagy, and the expression level of BNIP3 and LC3-II/LC3-I were up-regulated (P < 0.05), while p62 was down-regulated (P < 0.05) compared with the control group. The expression level of LC3-II/LC3-I in the high-intensity exercise group was higher (P < 0.05), but the expression level of p62 was lower than that in the moderate-intensity exercise group and the expression of BNIP3 was decreased (P < 0.05). (4) To conclude, 4-week moderate-intensity exercise can promote the removal of damaged mitochondria and maintain skeletal muscle function by increasing BNIP3-regulated mitophagy in skeletal muscle. In high-intensity exercise, the level of autophagy is higher, but will cause harmful effect on skeletal muscle.

Key words: mitophagy, BNIP3, skeletal muscle, exercise intensity

CLC Number:

Yu Liang, Zhao Zeming, Zhao Binting, Li Lin, Liu Ziming, Wang Zhen, Wang Ruiyuan.

Effects of different intensities of exercises on BNIP3-mediated mitophagy in skeletal muscle [J]. Chinese Journal of Tissue Engineering Research, 2020, 24(5): 682-688.

Figures/Tables 10

References

[1] GREEN DR, VAN HOUTEN B. SnapShot: Mitochondrial quality control.Cell.2011;147(4): 950.
[2] YOULE RJ, NARENDRA DP.Mechanisms of mitophagy.Nat Rev Mol Cell Biol.2011;12(1); 9-14.
[3] KABEYA Y, MIZUSSHIMA N, UENO T, et al.LC3, a mammalian homologue of yeast Apg8p, is localized in autophagosome membranes after processing.EMBO J. 2000; 19(21): 5720-5728.
[4] GOZUACIK D,KINICHI A.Autophagy as a cell death and tumor suppressor mechanism.Oncogene.2004; 23: 2891-2906.
[5] WAN J, MARTINVALET D, JI X, et al.The Bcl-2 family pro apoptotic molecule,BNIP3 regulates activation-induced celldeath of effector cytotoxic T lymphocytes.Immunology. 2003;110(1):10-17．
[6] DAIDO S, KANZAWA T, YAMAMATO A, et al. Pivotal role of the cell death factor BNIP3 in ceramide-induced autophagic cell death in malignant gilma cells.Cancer Res.2004;64(12): 4286-4293.
[7] VASAGIRI N, KUTALA VK. Structure, function, and epigenetic regulation of BNIP3: a pathophysiological relevance.Mol Biol Rep.2014;41:7705-7714.
[8] FENG X, LIU X, ZHANG W, et al. p53 directly suppresses BNIP3 expression to protect against hypoxia-induced cell death.EMBO J.2011;30:3397-3415.
[9] 崔迪,贺杰,孙婧瑜,等.耐力训练与p53抑制剂PFT-α对小鼠骨骼肌线粒体自噬相关基因表达的影响[J].天津体育学院学报,2013, 28(5):422-426.
[10] JIN Z, LI Y, PITTI R, et al.Cullin3-based polyubiquitination and p62-dependent aggregation of caspase-8 mediate extrinsic apoptosis signaling.Cell.2009;137(4):721-735.
[11] KIRIN V, LAMARK T, JOHANSEN T, et al.NBR1 cooperates with p62 in selective autophagy of ubiquitinated targets. Autophagy.2009,5(5):732-733.
[12] FENG Z, BAI L, YAN L, et al.Mitochondrial dynamic remodeling instrenuous exercise-induced muscle and mitochondrial dysfunction: Regulatory effects of hydroxytyrosol. Free Radic Biol Med.2011; 50(10):1437-1446.
[13] GOLBIDI S, Laher RI.Molecular mechanisms in exercise-induced cardioprotection.Cardiol Res Pract. 2011; 2011:972807.
[14] GRUMATI P, COLETTO L, SCHIAVINATO A, et al. Physical exercise stimulates autophagy in normal skeletal muscles but is detrimental for collagen VI-deficient muscles.Autophagy. 2011;7(12):1414-1423.
[15] 邱守涛,崔迪,付绍婷,等.不同强度耐力运动对骨骼肌质量的影响:自噬与衰老[J].沈阳体育学院学报,2015,34(1):78-84+90.
[16] LIRA VA, OKUTSU M, ZHANG M, et al.Autophagy is required for exercise traing-induced skeletal muscle adaption and improvement of physical performance.FESEB J.2013;27(10): 4184-4193.
[17] 于大堂,李茗芳,倪兵,等.大鼠脊髓损伤后自噬相关蛋白LC3和BNIP3的表达[J].第三军医大学学报,2013,35(9):841-845.
[18] 薄海,李玲,段富强,等.低氧联合运动对大鼠骨骼肌线粒体自噬的影响[J].中国康复医学杂志, 2014,29(10):908-912.
[19] HE C, BASSIK MC, MORESI V, et al.Exercise-induced BCL 2-regulated autophagy is required for muscle glucose homeostasis.Nature.2012;481(7382):511-515.
[20] QUINSAY MN, THOMAS RL, LEE Y, et al.Bnip3-mediated mito-chondrial autophagy is independent of the mitochondrial permeabili-ty transition pore.Autophagy.2010;6(7): 855-862．
[21] KIM JY, KIM YJ, LEE S, et al. BNip3 is a mediator of TNF-in-duced necrotic cell death.Aoptosis. 2011,16(2): 114-126．
[22] HE C, SUMPTER R JR, LEVINE B.Exercise induces autophagy in peripheral tissues and in the brain. Autophagy. 2012;8(10):1548-1551.
[23] MIZUSHIMA N, YOSHIMORI T, LEVINE B. Methods in mammalian autophagy research.Cell.2010;140(3): 313-326.