Study on Mechanism of Myocardial Fibrosis in ApoE-/- Atherosclerotic Mice Inhibited by Aerobic Exercise

doi:10.12114/j.issn.1007-9572.2023.0516

Abstract

Abstract:

Background

Atherosclerosis (AS) causes cardiovascular diseases such as myocardial infarction and myocardial fibrosis. Incidence of the population gradually increases with the aging of the global population. The inflammatory response is a key factor in myocardial fibrosis, and regular aerobic exercise can reduce inflammation and protect myocardial function. However, the protective mechanism of aerobic exercise against AS myocardial fibrosis is unclear.

Objective

To investigate the mechanism of the effect of aerobic exercise on myocardial fibrosis in AS mice.

Methods

From February to August 2022, twenty-seven 8-week-old male ApoE^-/- mice were selected as the experimental subjects and randomly divided into the control group, model group and aerobic exercise group, with 9 mice in each group. The mouse model of AS was prepared, and the mice were trained with exercise. The myocardial tissue was observed by hematoxylin-eosin (HE) and Masson staining. The protein expressions of NOD receptor 3 (NLRP3), interleukin1β (IL-1β) and transforming growth factor β1 (TGF-β1) in myocardial tissue were detected by Western blotting. The expressions of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were detected.

Results

Masson staining results showed that myocardial fibrosis in the model group was significantly worse than that in the control group. Myocardial fibrosis in the aerobic exercise group was significantly improved compared with the model group. HE staining showed that myocardial cells in the model group were disorganized, with abnormal cell morphology and size, enlarged cell gaps and inflammatory cell infiltration. Cardiomyocytes of mice in the aerobic exercise group were still neatly arranged, with abnormal cell morphology and size, and the cell gap was basically normal. The expressions of NLRP3, IL-1β and TGF-β1 in the model group were higher than those in the control group, while the expressions of NLRP3, IL-1β and TGF-β1 in the aerobic exercise group were lower than those in the model group, and higher than the control group (P<0.05). The expressions of SOD and GSH-Px in the model group were lower than those in the control group, and the expressions of SOD and GSH-Px in the aerobic exercise group were higher than those in the model group, and lower than those in the control group (P<0.05) .

Conclusion

Aerobic exercise significantly improved myocardial fibrosis in ApoE^-/- AS mice, and the mechanism may be related to inhibiting myocardial inflammatory response and activating antioxidant levels.

Key words: Atherosclerosis, Fibrosis, Aerobic exercise, Inflammation, ApoE^-/- mice

摘要：

背景

动脉粥样硬化（AS）会引发心肌梗死、心肌纤维化等心血管病变，随着全球人口老龄化加重，发病人群逐渐增多。炎症反应是心肌纤维化的关键因素，规律的有氧运动可以减轻炎症保护心肌功能。但有氧运动对AS心肌纤维化的保护机制尚不清楚。

目的

本研究旨在探讨有氧运动对AS小鼠心肌纤维化的影响机制。

方法

2022年2—8月选取27只8周龄的雄性ApoE^-/-小鼠作为实验对象，将小鼠随机分为对照组、模型组和有氧运动组，每组9只。制备AS小鼠模型，对小鼠进行运动训练，Masson染色、苏木素-伊红（HE）染色观察心肌组织情况，蛋白质印迹法（Western blotting）检测心肌组织NOD受体3（NLRP3）、白介素1β（IL-1β）、转化生长因子β1（TGF-β1）蛋白表达情况，检测超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）表达量。

结果

Masson染色结果示模型组心肌组织纤维化较对照组明显加重；有氧运动组心肌组织纤维化较模型组明显改善。HE染色结果示模型组小鼠心肌细胞排列较错乱，细胞形态、大小异常，细胞间隙增大，存在炎性细胞浸润；有氧运动组小鼠心肌细胞排列尚整齐，细胞形态、大小异常，细胞间隙基本正常。模型组NLRP3、IL-1β、TGF-β1蛋白表达高于对照组，有氧运动组NLRP3、IL-1β、TGF-β1蛋白表达低于模型组、高于对照组（P<0.05）。模型组SOD、GSH-Px表达量低于对照组，有氧运动组SOD、GSH-Px表达量高于模型组、低于对照组（P<0.05）。

结论

有氧运动明显改善ApoE^-/- AS小鼠心肌纤维化，其机制可能与抑制心肌炎性反应、激活抗氧化水平有关。

关键词: 动脉粥样硬化, 纤维化, 有氧运动, 炎症, ApoE^-/-小鼠

QIN Fang,MA Tiantian,YU Zifu, et al. Study on Mechanism of Myocardial Fibrosis in ApoE^-/- Atherosclerotic Mice Inhibited by Aerobic Exercise[J]. Chinese General Practice, 2024, 27(05): 557-562. DOI: 10.12114/j.issn.1007-9572.2023.0516.
秦芳,马甜甜,于子夫等. 有氧运动抑制炎症反应改善ApoE^-/-动脉粥样硬化小鼠心肌纤维化机制研究[J]. 中国全科医学, 2024, 27(05): 557-562. DOI: 10.12114/j.issn.1007-9572.2023.0516.

Figures/Tables 5

References 31

[1]	朱迪，曹烨民. 动脉粥样硬化抗炎治疗的研究进展[J]. 中国现代医学杂志，2023,33(5):50-55. DOI：10.3969/j.issn.1005-8982.2023.05.008.
[2]	WORKE L J, BARTHOLD J E, SEELBINDER B，et al. Densification of typeⅠ collagen matrices as a model for cardiac fibrosis[J]. Adv Healthc Mater，2017,6(22):10.1002/adhm.201700114. DOI：10.1002/adhm.201700114.
[3]	杨晓利，瞿惠燕，戎靖枫，等. 心肌纤维化发病机制的研究进展[J]. 中西医结合心脑血管病杂志，2020,18(14):2255-2258. DOI：10.12102/j.issn.1672-1349.2020.14.014.
[4]	CADENAS S. ROS and redox signaling in myocardial ischemia-reperfusion injury and cardioprotection[J]. Free Radic Biol Med，2018,117:76-89. DOI：10.1016/j.freeradbiomed.2018.01.024.
[5]	刘泽鑫，曹赛，陈清，等. MicroRNA-132通过诱导线粒体氧化应激障碍-铁死亡进程促进动脉粥样硬化[J]. 南方医科大学学报，2022,42(1):143-149. DOI：10.12122/j.issn.1673-4254.2022.01.18.
[6]	VAN DER POL A, VAN GILST W H, VOORS A A，et al. Treating oxidative stress in heart failure：past，present and future[J]. Eur J Heart Fail，2019,21(4):425-435. DOI：10.1002/ejhf.1320.
[7]	SOORI R, AMINI A A, CHOOBINEH S，et al. Exercise attenuates myocardial fibrosis and increases angiogenesis-related molecules in the myocardium of aged rats[J]. Arch Physiol Biochem，2022,128(1):1-6. DOI：10.1080/13813455.2019.1660370.
[8]	XI Y, LI Y X, REN W J，et al. ELABELA-APJ-akt/YAP signaling axis：a novel mechanism of aerobic exercise in cardioprotection of myocardial infarction rats[J]. Med Sci Sports Exerc，2023,55(7):1172-1183. DOI：10.1249/MSS.0000000000003143.
[9]	PAGAN L U, DAMATTO R L, CEZAR M D，et al. Long-term low intensity physical exercise attenuates heart failure development in aging spontaneously hypertensive rats[J]. Cell Physiol Biochem，2015,36(1):61-74. DOI：10.1159/000374053.
[10]	ZHU X J, CHEN L H, LI J H. The effects of aerobic exercise on plasma adiponectin level and adiponectin-related protein expression in myocardial tissue of ApoE（-/-）mice[J]. J Sports Sci Med，2015,14(4):877-882.
[11]	HU D Y. New guidelines and evidence for prevention and treatment of dyslipidemia and atherosclerotic cardiovascular disease in China[J]. Chronic Dis Transl Med，2016,3(2):73-74. DOI：10.1016/j.cdtm.2016.11.001.
[12]	CHEN Y, HUANG Q, FENG Y. Exercise improves cardiac function in the aged rats with myocardial infarction[J]. Physiol Res，2023,72(1):27-35. DOI：10.33549/physiolres.934966.
[13]	赵浩茜，邹慧玲，胡芳. 有氧运动抑制自发性高血压大鼠心肌中HMGB1/TLR4炎症通路[J]. 现代生物医学进展，2018,18(19):3633-3636; 3633-3636,3697. DOI：10.13241/j.cnki.pmb.2018.19.007.
[14]	耿元文，林琴琴，王湘怡，等. 间歇运动对心梗大鼠心肌氧化应激和炎症的影响及其机制[J]. 中国应用生理学杂志，2021,37(4):439-444. DOI：10.12047/j.cjap.6094.2021.043.
[15]	REN C Z, ZHAO X K, LIU K，et al. Research progress of natural medicine Astragalus mongholicus Bunge in treatment of myocardial fibrosis[J]. J Ethnopharmacol，2023,305:116128. DOI：10.1016/j.jep.2022.116128.
[16]	JANOUDI A, SHAMOUN F E, KALAVAKUNTA J K，et al. Cholesterol crystal induced arterial inflammation and destabilization of atherosclerotic plaque[J]. Eur Heart J，2016,37(25):1959-1967. DOI：10.1093/eurheartj/ehv653.
[17]	RALSTON J C, LYONS C L, KENNEDY E B，et al. Fatty acids and NLRP3 inflammasome-mediated inflammation in metabolic tissues[J]. Annu Rev Nutr，2017,37:77-102. DOI：10.1146/annurev-nutr-071816-064836.
[18]	LV S L, ZENG Z F, GAN W Q，et al. Lp-PLA2 inhibition prevents Ang II-induced cardiac inflammation and fibrosis by blocking macrophage NLRP3 inflammasome activation[J]. Acta Pharmacol Sin，2021,42(12):2016-2032. DOI：10.1038/s41401-021-00703-7.
[19]	NADLONEK N, LEE J H, REECE T B，et al. Interleukin-1 Beta induces an inflammatory phenotype in human aortic valve interstitial cells through nuclear factor kappa Beta[J]. Ann Thorac Surg，2013,96(1):155-162. DOI：10.1016/j.athoracsur.2013.04.013.
[20]	WANG Y L, LI Y L, WU Y N，et al. 5TNF-α and IL-1β neutralization ameliorates angiotensin II-induced cardiac damage in male mice[J]. Endocrinology，2014,155(7):2677-2687. DOI：10.1210/en.2013-2065.
[21]	蒲咏秋. 跑台运动对心力衰竭小鼠心功能及心肌损伤的影响[J]. 基因组学与应用生物学，2020,39(9):4227-4234. DOI：10.13417/j.gab.039.004227.
[22]	CUI X N, WANG K, ZHANG J H，et al. Aerobic exercise ameliorates myocardial fibrosis via affecting vitamin D receptor and transforming growth factor-β1 signaling in vitamin D-deficient mice[J]. Nutrients，2023,15(3):741. DOI：10.3390/nu15030741.
[23]	WU X Y, ZHU J, WEI Y L，et al. MicroRNA-663 participates in myocardial fibrosis through interaction with TGF-β1[J]. Exp Ther Med，2019,18(4):3172-3176. DOI：10.3892/etm.2019.7902.
[24]	SUN J, ZHU J X, CHEN L，et al. Forsythiaside B inhibits myocardial fibrosis via down regulating TGF-β1/Smad signaling pathway[J]. Eur J Pharmacol，2021,908:174354. DOI：10.1016/j.ejphar.2021.174354.
[25]	刘亚，刘霞，邓鹏辉，等. 运动对糖尿病心肌纤维化大鼠心肌Ⅰ、Ⅲ型胶原及血管紧张素Ⅱ/转化生长因子β1/Smad2通路的影响[J]. 中国组织工程研究，2022,26(26):4173-4179.
[26]	WANG S Q, LI D, YUAN Y. Long-term moderate intensity exercise alleviates myocardial fibrosis in type 2 diabetic rats via inhibitions of oxidative stress and TGF-β1/Smad pathway[J]. J Physiol Sci，2019,69(6):861-873. DOI：10.1007/s12576-019-00696-3.
[27]	KOGA K, YOKOI H, MORI K，et al. microRNA-26a inhibits TGF-β-induced extracellular matrix protein expression in podocytes by targeting CTGF and is downregulated in diabetic nephropathy[J]. Diabetologia，2015,58(9):2169-2180. DOI：10.1007/s00125-015-3642-4.
[28]	HORI M, NISHIDA K. Oxidative stress and left ventricular remodelling after myocardial infarction[J]. Cardiovasc Res，2009,81(3):457-464. DOI：10.1093/cvr/cvn335.
[29]	JIANG F, LIU G S, DUSTING G J，et al. NADPH oxidase-dependent redox signaling in TGF-β-mediated fibrotic responses[J]. Redox Biol，2014,2:267-272. DOI：10.1016/j.redox.2014.01.012.
[30]	WEI L F, ZHANG H M, WANG S S，et al. Changes of MDA and SOD in brain tissue after secondary brain injury with seawater immersion in rats[J]. Turk Neurosurg，2016,26(3):384-388. DOI：10.5137/1019-5149.JTN.8265-13.1.
[31]	纪新博，顾申红，麦华德，等. Prdx1过表达通过Nrf2/HO-1信号通路抑制氧化应激减轻自发性高血压大鼠心肌肥厚和纤维化[J]. 安徽医科大学学报，2023,58(2):196-201. DOI：10.19405/j.cnki.issn1000-1492.2023.02.004.

组别	只数	NLRP3	IL-1β	TGF-β1
对照组	9	1.123±0.110	1.136±0.119	1.162±0.184
模型组	9	5.741±0.220^ab	6.447±0.524^ab	7.906±0.658^ab
有氧运动组	9	2.851±0.279^a	3.724±0.140^a	2.624±0.244^a
F值		353.02	201.52	215.98
P值		<0.001	<0.001	<0.001

组别	只数	NLRP3	IL-1β	TGF-β1
对照组	9	1.123±0.110	1.136±0.119	1.162±0.184
模型组	9	5.741±0.220^ab	6.447±0.524^ab	7.906±0.658^ab
有氧运动组	9	2.851±0.279^a	3.724±0.140^a	2.624±0.244^a
F值		353.02	201.52	215.98
P值		<0.001	<0.001	<0.001

组别	只数	SOD	GSH-Px
对照组	9	32.325±0.754	25.464±1.067
模型组	9	12.879±0.133^ab	8.672±1.056^ab
有氧运动组	9	21.615±0.432^a	15.990±0.608^a
F值		314.13	729.53
P值		<0.001	<0.001

组别	只数	SOD	GSH-Px
对照组	9	32.325±0.754	25.464±1.067
模型组	9	12.879±0.133^ab	8.672±1.056^ab
有氧运动组	9	21.615±0.432^a	15.990±0.608^a
F值		314.13	729.53
P值		<0.001	<0.001