scholarly journals Exercise Training Alleviates Cardiac Fibrosis through Increasing Fibroblast Growth Factor 21 and Regulating TGF-β1-Smad2/3-MMP2/9 Signaling in Mice with Myocardial Infarction

2021 ◽  
Vol 22 (22) ◽  
pp. 12341
Author(s):  
Yixuan Ma ◽  
Yixin Kuang ◽  
Wenyan Bo ◽  
Qiaoqin Liang ◽  
Wenfei Zhu ◽  
...  

Exercise training has been reported to alleviate cardiac fibrosis and ameliorate heart dysfunction after myocardial infarction (MI), but the molecular mechanism is still not fully clarified. Fibroblast growth factor 21 (FGF21) exerts a protective effect on the infarcted heart. This study investigates whether exercise training could increase FGF21 protein expression and regulate the transforming growth factor-β1 (TGF-β1)-Smad2/3-MMP2/9 signaling pathway to alleviate cardiac fibrosis following MI. Male wild type (WT) C57BL/6J mice and Fgf21 knockout (Fgf21 KO) mice were used to establish the MI model and subjected to five weeks of different types of exercise training. Both aerobic exercise training (AET) and resistance exercise training (RET) significantly alleviated cardiac dysfunction and fibrosis, up-regulated FGF21 protein expression, inhibited the activation of TGF-β1-Smad2/3-MMP2/9 signaling pathway and collagen production, and meanwhile, enhanced antioxidant capacity and reduced cell apoptosis in the infarcted heart. In contrast, knockout of Fgf21 weakened the cardioprotective effects of AET after MI. In vitro, cardiac fibroblasts (CFs) were isolated from neonatal mice hearts and treated with H2O2 (100 μM, 6 h). Recombinant human FGF21 (rhFGF21, 100 ng/mL, 15 h) and/or 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR, 1 mM, 15 h) inhibited H2O2-induced activation of the TGF-β1-Smad2/3-MMP2/9 signaling pathway, promoted CFs apoptosis and reduced collagen production. In conclusion, exercise training increases FGF21 protein expression, inactivates the TGF-β1-Smad2/3-MMP2/9 signaling pathway, alleviates cardiac fibrosis, oxidative stress, and cell apoptosis, and finally improves cardiac function in mice with MI. FGF21 plays an important role in the anti-fibrosis effect of exercise training.

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Mengxin Cai ◽  
Shaojun Du ◽  
Zhenjun Tian

Objective Myocardial infarction (MI) remains a leading cause of morbidity and mortality worldwide. Exercise training could improve cardiac function following MI. However, the mechanisms are still not well-known. Neuregulin 1 (NRG1)plays an important role in heart development and regeneration.In this study, we investigated the effect of NRG1 on cardiac regeneration in a zebrafish model, detected whether exercise could improve cardiac function through regulating NRG1 expression in infarcted heart and explore the possible role of up-regulation of NRG1 in skeletal muscle play in the cardioprotective effects in rats with MI. Methods Transgenic zebrafish line, cmlc2:CreERandβ-act2:BSNrg1,wereusedto study the effect of NRG1 on heart growth and regeneration after injury. PCNA was detected by immunofluorescence staining andmRNAexpression of gata4, nkx2.5, tbx5, smyd1b, hsp90α and murf were tested by RT-PCR.Sprague-Dawley rats were used to establish MI model and underwent fourweeks of exercise training (ET) or pAAV-{dMCK promoter}rNRG1-eGFP intervention.AG1478 was used asan inhibitor of NRG1/ErbBs signaling pathway. Cardiac function and structure,cardiomyocyte proliferation and NRG1 expression were detected in the heart or skeletal. Results Cardiac-specific overexpression of NRG1 induced cardiac hypertrophy and cardiomyocyte proliferation, regulated the mRNA expression of gata4, nkx2.5, tbx5, smyd1b, hsp90α andmurf in uninjuriedzebrafish, and promote cardiac repair and regeneration after injury in the zebrafish.Exercise activated NRG1/ErbBs signaling pathway, improved cardiac remodeling and heart function, enhanced cardiomyocyte proliferation, reduced cardiomyocyte apoptosis, ROS level and MuRF1 protein expression in rats with MI. BlockingErbB signaling attenuated the ET-induced cardioprotection effects in rat with MI.up-regulation of NRG1 expression in skeletal muscle could increase the protein level of NRG1 in serum and infarcted heart, improve cardiomyocyte proliferation and reduce the level of cardiac fibrosis, finally promote cardiac function. Conclusions Up-regulation of NRG1 expression in the heart or skeletal musclemay be one of the underlying mechanisms of thebeneficial effects of exercise training following MI.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255344
Author(s):  
Sun Young Jang ◽  
Soo Hyun Choi ◽  
Don Kikkawa ◽  
Eun Jig Lee ◽  
Jin Sook Yoon

Purpose The role of fibroblast growth factor (FGF) in orbital fibroblasts (OFs) is rarely known. In this study, we investigated the effect of FGF10 on fibrosis and the inflammation mechanism of Graves′ orbitopathy (GO). Methods Orbital tissue from GO (n = 15) and non-GO (n = 15) was obtained for this study. The mRNA and protein expression levels of FGF10 and FGF receptor 2b (FGFR2b) in orbital tissue were determined by real-time polymerase chain reaction, western blot analysis, and confocal microscopy. The effects of FGF10 on transforming growth factor (TGF)-β1 induced fibrotic proteins and interleukin (IL)-1β- or tumor necrosis factor (TNF)-α- induced inflammatory proteins were investigated using recombinant human (rh) FGF10 and small interfering (si) RNA transfection against FGF10. Results FGF10 and FGFR2b mRNA expression levels were significantly lower in GO orbital tissues than in non-GO orbital tissues (p = 0.009 and 0.005, respectively). Immunostaining of FGF10 in orbital adipose tissues showed differences in FGF10 expression between GO and control samples. Immunostaining of FGF10 was very weak in the orbital tissues of GO patients. TGF-β1-induced fibronectin, collagen Iα, α-smooth muscle actin protein expression in GO OFs was attenuated by rhFGF10 treatment and increased by knockdown of FGF10 via siFGF10 transfection. Similarly, IL-1β- or TNF-α-induced IL-6, IL-8, and cyclooxygenase-2 protein production in GO OFs was either blocked by rhFGF10 treatment or further upregulated by inhibition of FGF10 via siFGF10 transfection. Conclusions Our data demonstrate that FGF10 has beneficial effects on the inflammatory and fibrotic mechanisms of GO in primary cultured OFs, providing new insights into GO pathology and the discovery of FGF10 as a promising novel therapeutic application for the treatment of GO.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 368-368
Author(s):  
Jianguo Wang ◽  
Xiaoyan Zhu ◽  
Baoyu Zhao

Abstract Background: Fibroblast growth factor 21 (FGF21) plays essential roles in the regulation of whole body energy metabolism. However, it is not entirely clear for dairy cows whether FGF21 activates AMPK signaling pathway and what will be affected for lipid metabolism in bovine hepatocytes. Methods: Bovine hepatocytes were isolated from caudate lobes by using three-step of perfusion and collagenase digestion method. The accumulation of TG and the secretion of VLDL were examined in hepatocytes and supernatant, respectively. The expressions of the metabolic key factors were detected by Real-time PCR and Western Blot.Results: The 4th hour is the optimal time that FGF21 activates AMPK. FGF21 has significant dose-dependent inhibition of TG in bovine hepatocytes; and high concentration (1800 pg/mL) significantly promoted VLDL secretion at 4 h. The protein expression of APOB 100, APOE and MTTP, which are components of VLDL, were stimulated by FGF21, and all the mRNA expression reached the peak point (P < 0.01) at medium concentration (900 pg/mL). Interestingly, the proteins associated with lipid transportation were promoted too, such as LDLR, CD36, L-FABP. To some extent, meanwhile, it could be observed that some genes regulating lipid oxidation were strengthened following FGF21 treatment. In detail, ACOX1 and SIRT1 were very sensitive to the concentration of FGF21, showing remarkable difference at low concentration (P < 0.01); PGC-α, PPAR-α and CPT-1 showed significant changes at 900 pg/mL (P < 0.01); CPT-2 required a higher concentration to achieve significant enhancement. However, the results had a negative impact on lipogenesis. SREBP1c, ACC, FASN and ACLY were inhibited after treatment with low or medium doses of FGF21 (P < 0.01). Conclusion: FGF21 can promote lipid oxidation and transport, while inhibit lipid synthesis via activating AMPK signalling pathway in primary hepatocytes of dairy cows, thereby participation in the adaptive regulation of energy metabolism.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Nathaniel Girer ◽  
Victoria Rontoyanni ◽  
Craig Porter ◽  
Cornelis Elferink

Abstract Fibroblast growth factor 21 (FGF21) is an important liver-secreted hormone that activates thermogenesis in white and brown fat deposits. In various models of obesity, FGF21 administration consistently facilitates weight loss and improved metabolic function. Several FGF21 variants, which have been engineered to improve protein stability and solubility in solutions containing preservatives, are currently in human clinical trials. In addition, in vivo FGF21 gene therapy using viral vector is being explored as an alternative therapeutic approach. In this study, we present a simpler method of in vivo FGF21 gene therapy, in which liver-specific delivery of an unpackaged plasmid construct expressing an HA-tagged FGF21 protein increases de novo hepatic FGF21 production and secretion in mice. Our data show that FGF21 protein expression can be successfully restored into the livers of FGF21 conditional knockout mice for at least two weeks after a single tail vein injection with the expression plasmid, and that the HA-tagged protein is secreted and readily detectable in serum. In wild-type C57BL6/J mice, in vivo plasmid delivery significantly increased hepatic FGF21 protein 2.3-fold after two weeks, and was associated with reduced body mass and a 14% reduction in fasting serum glucose. In addition, elevated hepatic FGF21 levels correlated with a 27% decrease in the ratio of fat to body mass, visibly smaller subcutaneous and visceral white fat adipocytes, and a 3.3-fold increase in uncoupling protein 1-dependent mitochondrial respiration in the white fat. Together, these data suggest that in vivo plasmid delivery may potentially be an effective strategy for promoting hepatic FGF21 expression in models of obesity. We are currently testing this hypothesis with experiments in high-fat diet-challenged mice.


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