scholarly journals Up-regulating autophagy by targeting the mTOR-4EBP1 pathway: a possible mechanism for improving cardiac function in mice with experimental dilated cardiomyopathy

2020 ◽  
Author(s):  
Bo Jin ◽  
Haiming Shi ◽  
Zhu Jun ◽  
Bangwei Wu ◽  
Quzhen Geshang

Abstract Background: Autophagy plays a crucial role in the pathological process of cardiovascular diseases. However, little is known about the pathological mechanism underlying autophagy regulation in dilated cardiomyopathy (DCM). Methods: We explored whether up-regulating autophagy could improve cardiac function in mice with experimental DCM through the mTOR-4EBP1 pathway. Animal model of DCM was established in BALB/c mice by immunization with porcine cardiac myosin. Both up- or down-regulation of autophagy were studied by administration of rapamycin or 3-MA in parallel. Morphology, Western blotting, and echocardiography were applied to confirm the pathological mechanisms. Results: Autophagy was activated and autophagosomes were significantly increased in the rapamycin group. The collagen volume fraction (CVF) was decreased in the rapamycin group compared with the DCM group (9.21 ± 0.82 % vs 14.38 ± 1.24 %, P<0.01). The expression of p-mTOR and p-4EBP1 were significantly decreased in rapamycin-induced autophagy activation, while the levels were increased by down-regulating autophagy with 3-MA. In the rapamycin group, the LVEF and FS were significantly increased compared with the DCM group (54.12 ± 6.48 % vs 45.29 ± 6.68 %, P <0.01; 26.89 ± 4.04 % vs 22.17 ± 2.82 %, P <0.05). As the inhibitor of autophagy, 3-MA aggravated the progress of maladaptive cardiac remodeling and declined cardiac function in DCM mice. Conclusions: The study indicated a possible mechanism for improving cardiac function in mice with experimental DCM by up-regulating autophagy via the mTOR-4EBP1 pathway, which could be a promising therapeutic strategy for DCM.

2019 ◽  
Author(s):  
Bo Jin ◽  
Haiming Shi ◽  
Zhu Jun ◽  
Bangwei Wu ◽  
Quzhen Geshang

Abstract Background: Autophagy plays a crucial role in the pathological process of cardiovascular diseases. However, little is known about the pathological mechanism underlying autophagy regulation in dilated cardiomyopathy (DCM).Methods: We explored whether up-regulating autophagy could improve cardiac function in mice with experimental DCM through the mTOR-4EBP1 pathway. Animal model of DCM was established in BALB/c mice by immunization with porcine cardiac myosin. Both up- or down-regulation of autophagy were studied by administration of rapamycin or 3-MA in parallel. Morphology, Western blotting, and echocardiography were applied to confirm the pathological mechanisms.Results: Autophagy was activated and autophagosomes were significantly increased in the rapamycin group. The collagen volume fraction (CVF) was decreased in the rapamycin group compared with the DCM group (9.21 ± 0.82 % vs 14.38 ± 1.24 %, P<0.01). The expression of p-mTOR and p-4EBP1 were significantly decreased in rapamycin-induced autophagy activation, while the levels were increased by down-regulating autophagy with 3-MA. In the rapamycin group, the LVEF and FS were significantly increased compared with the DCM group (54.12 ± 6.48 % vs 45.29 ± 6.68 %, P<0.01; 26.89 ± 4.04 % vs 22.17 ± 2.82 %, P<0.05). As the inhibitor of autophagy, 3-MA aggravated the progress of maladaptive cardiac remodeling and declined cardiac function in DCM mice.Conclusions: The study indicated a possible mechanism for improving cardiac function in mice with experimental DCM by up-regulating autophagy via the mTOR-4EBP1 pathway, which could be a promising therapeutic strategy for DCM.


2020 ◽  
Author(s):  
Bo Jin ◽  
Haiming Shi ◽  
Zhu Jun ◽  
Bangwei Wu ◽  
Quzhen Geshang

Abstract Background: Autophagy plays a crucial role in the pathological process of cardiovascular diseases. However, little is known about the pathological mechanism underlying autophagy regulation in dilated cardiomyopathy (DCM).Methods: We explored whether up-regulating autophagy could improve cardiac function in mice with experimental DCM through the mTOR-4EBP1 pathway. Animal model of DCM was established in BALB/c mice by immunization with porcine cardiac myosin. Both up- or down-regulation of autophagy were studied by administration of rapamycin or 3-MA in parallel. Morphology, Western blotting, and echocardiography were applied to confirm the pathological mechanisms.Results: Autophagy was activated and autophagosomes were significantly increased in the rapamycin group. The collagen volume fraction (CVF) was decreased in the rapamycin group compared with the DCM group (9.21 ± 0.82 % vs 14.38 ± 1.24 %, P<0.01). The expression of p-mTOR and p-4EBP1 were significantly decreased in rapamycin-induced autophagy activation, while the levels were increased by down-regulating autophagy with 3-MA. In the rapamycin group, the LVEF and FS were significantly increased compared with the DCM group (54.12 ± 6.48 % vs 45.29 ± 6.68 %, P<0.01; 26.89 ± 4.04 % vs 22.17 ± 2.82 %, P<0.05). As the inhibitor of autophagy, 3-MA aggravated the progress of maladaptive cardiac remodeling and declined cardiac function in DCM mice.Conclusions: The study indicated a possible mechanism for improving cardiac function in mice with experimental DCM by up-regulating autophagy via the mTOR-4EBP1 pathway, which could be a promising therapeutic strategy for DCM.


2017 ◽  
Vol 8 ◽  
Author(s):  
Robin Deloux ◽  
Damien Vitiello ◽  
Nathalie Mougenot ◽  
Philippe Noirez ◽  
Zhenlin Li ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Jinsheng Lai ◽  
Chen Chen

Epoxyeicosatrienoic acids (EETs) are metabolites of arachidonic acid by cytochrome P450 (CYP) epoxygenases, which include four regioisomers: 5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET. Each of them possesses beneficial effects against inflammation, fibrosis, and apoptosis, which could combat cardiovascular diseases. Numerous studies have demonstrated that elevation of EETs by overexpression of CYP2J2, inhibition of sEH, or treatment with EET analogs showed protective effects in various cardiovascular diseases, including hypertension, myocardial infarction, and heart failure. As is known to all, cardiac remodeling is the major pathogenesis of cardiovascular diseases. This review will begin with the introduction of EETs and their protective effects in cardiovascular diseases. In the following, the roles of EETs in cardiac remodeling, with a particular emphasis on myocardial hypertrophy, apoptosis, fibrosis, inflammation, and angiogenesis, will be summarized. Finally, it is suggested that upregulation of EETs is a potential therapeutic strategy for cardiovascular diseases. The EET-related drug development against cardiac remodeling is also discussed, including the overexpression of CYP2J2, inhibition of sEH, and the analogs of EET.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Huiyang Chen ◽  
Lixia Lou ◽  
Dongmei Zhang ◽  
Yizhou Zhao ◽  
Jing Zhao ◽  
...  

Qiliqiangxin capsule (QLC), a natural herb recipe with therapeutic effect from China, has been widely used in clinical practice for attenuating cardiac remodeling induced by myocardial infarction (MI). However, the pharmacological mechanism of QLC on cardiac remodeling after MI is not entirely clear. The present study aims to investigate the effectiveness and mechanisms of QLC on cardiac remodeling induced by MI in rats. The animal model was established by permanently ligating the left anterior descending coronary artery in rats. Subsequently, rats with successful ligation were randomly divided into model group, captopril group, and QLC group. And the control group was operated upon in parallel except ligation, namely, the sham group. All rats were treated through the intragastric administration once a day for 4 weeks. Cardiac hemodynamics was measured after treatment. Then, the left ventricular mass index (LVMI) was examined. The pathological changes were observed by HE staining. The collagen volume fraction (CVF) was detected by Masson trichrome staining. The apoptosis index was obtained by TUNEL fluorescent staining. The miR-133a and mRNA of TGF-β1, CTGF, Caspase9, and Caspase3 were examined by real-time PCR. The protein expressions of TGF-β1, CTGF, Caspase9, Caspase3, and cleaved-Caspase3 were tested by Western blot. Compared with the model group, QLC partially improved cardiac hemodynamics and decreased LVMI. miR-133a was significantly increased in QLC group. In addition, QLC declined CVF by downregulating TGF-β1 rather than CTGF. Meanwhile, QLC decreased the apoptosis index by attenuating Caspase9, Caspase3, and cleaved-Caspase3. This study suggested that QLC could improve cardiac function and partially attenuate cardiac remodeling by attenuating fibrosis and decreasing apoptosis, which might be partially related to miR-133a, TGF-β1, Caspase9, and Caspase3.


2014 ◽  
Vol 21 (25) ◽  
pp. 2989-3006 ◽  
Author(s):  
Nadezda Apostolova ◽  
Milagros Rocha ◽  
Susana Rovira-Llopis ◽  
Celia Banuls ◽  
Rosa Falcon ◽  
...  

2019 ◽  
Vol 317 (6) ◽  
pp. H1301-H1311 ◽  
Author(s):  
Qiu-Yue Lin ◽  
Ping-Ping Lang ◽  
Yun-Long Zhang ◽  
Xiao-Lei Yang ◽  
Yun-Long Xia ◽  
...  

Intercellular adhesion molecule-1 (ICAM-1) is a member of an immunoglobulin-like superfamily of adhesion molecules that mediate leukocyte adhesion to vascular endothelium and are involved in several cardiovascular diseases, including ischemia-reperfusion injury, myocardial infarction, and atherosclerosis. However, the role of ICAM-1 in angiotensin II (ANG II)-induced cardiac remodeling in mice remains unclear. Wild-type mice were administered an IgG control or ICAM-1 neutralizing antibody (1 and 2 mg/mouse, respectively) and ANG II (1,000 ng·kg−1·min−1) for up to 14 days. Cardiac contractile function and structure were detected by echocardiography. Hypertrophy, fibrosis, and inflammation were assessed by histological examination. The infiltration of lymphocyte function-associated antigen-1 (LFA-1+) monocytes/macrophages was assessed by immunostaining. The mRNA expression of genes was evaluated by quantitative RT-PCR analysis. Protein levels were tested by immunoblotting. We found that ICAM-1 expression in ANG II-infused hearts and ICAM-1 levels in serum from human patients with heart failure were significantly increased. Moreover, ANG II infusion markedly enhanced ANG II-induced hypertension, caused cardiac contractile dysfunction, and promoted cardiac hypertrophy, fibrosis, and LFA-1+ macrophage infiltration. Conversely, blockage of ICAM-1 with a neutralizing antibody dose-dependently attenuated these effects. Moreover, our in vitro data further demonstrated that blocking ICAM-1 inhibited ANG II-induced LFA-1+ macrophage adhesion to endothelial cells and migration. In conclusion, these results provide novel evidence that blocking ICAM-1 exerts a protective effect in ANG II-induced cardiac remodeling at least in part through the modulation of adhesion and infiltration of LFA-1+ macrophages in the heart. Inhibition of ICAM-1 may represent a new therapeutic approach for hypertrophic heart diseases. NEW & NOTEWORTHY Leukocyte adhesion to vascular endothelium is a critical step in cardiovascular diseases. ICAM-1 is a member of immunoglobulin-like superfamily of adhesion molecules that binds LFA-1 to mediate leukocytes adhesion and migration. However, the significance of ICAM-1 in ANG II-induced cardiac remodeling remains unclear. This study reveals that blocking of ICAM-1 prevents ANG II-induced cardiac remodeling via modulating adhesion and migration of LFA-1+ monocytes, may serve as a novel therapeutic target for hypertensive cardiac diseases.


Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 545-555
Author(s):  
Hamad Al Shahi ◽  
Tomoyasu Kadoguchi ◽  
Kazunori Shimada ◽  
Kosuke Fukao ◽  
Satoshi Matsushita ◽  
...  

AbstractWe investigated the effects of voluntary exercise after myocardial infarction (MI) on cardiac function, remodeling, and inflammation. Male C57BL/6J mice were divided into the following four groups: sedentary + sham (Sed-Sh), sedentary + MI (Sed-MI), exercise + sham (Ex-Sh), and exercise + MI (Ex-MI). MI induction was performed by ligation of the left coronary artery. Exercise consisting of voluntary wheel running started after the operation and continued for 4 weeks. The Ex-MI mice had significantly increased cardiac function compared with the Sed-MI mice. The Ex-MI mice showed significantly reduced expression levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-10 in the infarcted area of the left ventricle compared with the Sed-MI mice. In the Ex-MI mice, the expression levels of fibrosis-related genes including collagen I and III were decreased compared to the Sed-MI mice, and the expression levels of IL-1β, IL-6, follistatin-like 1, fibroblast growth factor 21, and mitochondrial function-related genes were significantly elevated in skeletal muscle compared with the Sed mice. The plasma levels of IL-6 were also significantly elevated in the Ex-MI group compared with the Sed-MI groups. These findings suggest that voluntary exercise after MI may improve in cardiac remodeling associated with anti-inflammatory effects in the myocardium and myokine production in the skeletal muscles.


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