scholarly journals Low‐intensity Pulsed Ultrasound Ameliorates Angiotension Ii-induced Cardiac Fibrosisbyalleviating Inflammation via a Caveolin-1-dependent Pathway

2020 ◽  
Author(s):  
Kun Zhao ◽  
Jing Zhang ◽  
Tianhua Xu ◽  
Chuanxi Yang ◽  
Liqing Weng ◽  
...  

Abstract Background: Cardiac hypertrophy and fibrosis are major pathological manifestations observed in left ventricular remodeling induced by Angiotensin II (AngII). Concerning the fact that low‐intensity pulsed ultrasound (LIPUS) has been reported to improve cardiac dysfunction and myocardial fibrosis in myocardial infarction (MI) through mechanotransductionanditsdownstream pathways, we aimed to investigate whether LIPUS could also exert a protective effect on ameliorating AngII-induced cardiac hypertrophy and fibrosis andand if so, to further elucidate the underlying molecular mechanisms.Methods: In our study, we used AngII to mimic the animal and cell culture models of cardiac hypertrophy and fibrosis, where LIPUS irradiation (0.5MHz, 77.20mW/cm2) was applied for 20 minutes every 2 days from 1 week before surgery to 4 weeks after surgery in vivo, and every 6 hours for a total of 2 times in vitro. Following that, the levels of cardiac hypertrophy and fibrosis were evaluated by echocardiographic, histopathological, and molecular biological methods. Results: Our results showed that LIPUS irradiation could ameliorate left ventricular remodeling in vivo and cardiac fibrosis in vitro by reducing AngII-inducedrelease of inflammatory cytokines, while the protective effects were limited on cardiac hypertrophy in vitro. Given that LIPUS irradiation increased the expression of caveolin-1 related to mechanical stimulation, we inhibited caveolin-1 activity with pyrazolopyrimidine 2 (pp2) in vitro, by which LIPUS-induced downregulation of inflammation was reversed and the anti-fibrosis effects of LIPUS irradiation were absent. Conclusions: Taken together, these results indicate that LIPUS irradiation could ameliorate AngII-induced cardiac fibrosis by alleviating inflammation via a caveolin-1-dependent pathway, providing new insights for the development of novel therapeuticapparatus in clinical practice.

2015 ◽  
Vol 36 (4) ◽  
pp. 1305-1315 ◽  
Author(s):  
Chen-Hui Ju ◽  
Xian-Pei Wang ◽  
Chuan-Yu Gao ◽  
Shuang-Xia Zhang ◽  
Xing-Hua Ma ◽  
...  

Background/Aims: After myocardial infarction (MI), cardiac fibrosis greatly contributes to left ventricular remodeling and heart failure. The intermediate-conductance calcium-activated potassium Channel (KCa3.1) has been recently proposed as an attractive target of fibrosis. The present study aimed to detect the effects of KCa3.1 blockade on ventricular remodeling following MI and its potential mechanisms. Methods: Myocardial expression of KCa3.1 was initially measured in a mouse MI model by Western blot and real time-polymerase chain reaction. Then after treatment with TRAM-34, a highly selective KCa3.1 blocker, heart function and fibrosis were evaluated by echocardiography, histology and immunohistochemistry. Furthermore, the role of KCa3.1 in neonatal mouse cardiac fibroblasts (CFs) stimulated by angiotensin II (Ang II) was tested. Results: Myocardium expressed high level of KCa3.1 after MI. Pharmacological blockade of KCa3.1 channel improved heart function and reduced ventricular dilation and fibrosis. Besides, a lower prevalence of myofibroblasts was found in TRAM-34 treatment group. In vitro studies KCa3.1 was up regulated in CFs induced by Ang II and suppressed by its blocker.KCa3.1 pharmacological blockade attenuated CFs proliferation, differentiation and profibrogenic genes expression and may regulating through AKT and ERK1/2 pathways. Conclusion: Blockade of KCa3.1 is able to attenuate ventricular remodeling after MI through inhibiting the pro-fibrotic effects of CFs.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yang Zhao ◽  
Huaxin Sun ◽  
Kai Li ◽  
Luxiang Shang ◽  
Xiaoyan Liang ◽  
...  

Background. Cholinergic anti-inflammatory pathway (CAP) is implicated in cardioprotection in chronic heart failure (CHF) by downregulating inflammation response. Mitochondrial injuries play an important role in ventricular remodeling of the CHF process. Herein, we aim to investigate whether CAP elicitation prevents ventricular remodeling in CHF by protecting myocardial mitochondrial injuries and its underlying mechanisms. Methods and Results. CHF models were established by ligation of anterior descending artery for 5 weeks. Postoperative survival rats were assigned into 5 groups: the sham group (sham, n = 10 ), CHF group (CHF, n = 11 ), Vag group (CHF+vagotomy, n = 10 ), PNU group (CHF+PNU-282987 for 4 weeks, n = 11 ), and Vag+PNU group (CHF+vagotomy+PNU-282987 for 4 weeks, n = 10 ). The antiventricular remodeling effect of cholinergic elicitation was evaluated in vivo, and H9C2 cells were selected for the TNF-α gradient stimulation experiment in vitro. In vivo, CAP agitated by PNU-282987 alleviated the left ventricular dysfunction and inhibited the energy metabolism remodeling. Further, cholinergic elicitation increased myocardium ATP levels and reduced systemic inflammation. CAP induction alleviates macrophage infiltration and cardiac fibrosis, of which the effect is counteracted by vagotomy. Myocardial mitochondrial injuries were ameliorated by CAP activation, including the reserved ultrastructural integrity, declining ROS overload, reduced myocardial apoptosis, and enhanced mitochondrial fusion. In vitro, TNF-α intervention significantly exacerbated the mitochondrial damage in H9C2 cells. Conclusion. CAP elicitation effectively improves ischemic ventricular remodeling by suppressing systemic and cardiac inflammatory response, attenuating cardiac fibrosis and potentially alleviating the mitochondrial dysfunction linked to hyperinflammation reaction.


2017 ◽  
Vol 41 (3) ◽  
pp. 849-864 ◽  
Author(s):  
Yanqing Zhang ◽  
Pingping Liao ◽  
Meng’en Zhu ◽  
Wei Li ◽  
Dan Hu ◽  
...  

Background/Aims: Baicalin has been shown to be effective for various animal models of cardiovascular diseases, such as pulmonary hypertension, atherosclerosis and myocardial ischaemic injury. However, whether baicalin plays a role in cardiac hypertrophy remains unknown. Here we investigated the protective effects of baicalin on cardiac hypertrophy induced by pressure overload and explored the potential mechanisms involved. Methods: C57BL/6J-mice were treated with baicalin or vehicle following transverse aortic constriction or Sham surgery for up to 8 weeks, and at different time points, cardiac function and heart size measurement and histological and biochemical examination were performed. Results: Mice under pressure overload exhibited cardiac dysfunction, high mortality, myocardial hypertrophy, increased apoptosis and fibrosis markers, and suppressed cardiac expression of PPARα and PPARβ/δ. However, oral administration of baicalin improved cardiac dysfunction, decreased mortality, and attenuated histological and biochemical changes described above. These protective effects of baicalin were associated with reduced heart and cardiomyocyte size, lower fetal genes expression, attenuated cardiac fibrosis, lower expression of profibrotic markers, and decreased apoptosis signals in heart tissue. Moreover, we found that baicalin induced PPARα and PPARβ/δ expression in vivo and in vitro. Subsequent experiments demonstrated that long-term baicalin treatment presented no obvious cardiac lipotoxicity. Conclusions: The present results demonstrated that baicalin attenuates pressure overload induced cardiac dysfunction and ventricular remodeling, which would be due to suppressed cardiac hypertrophy, fibrosis, apoptosis and metabolic abnormality.


2020 ◽  
Vol 8 (1) ◽  
pp. e001081
Author(s):  
Jie Zhang ◽  
Meng Zhang ◽  
Zhi Yang ◽  
Shanying Huang ◽  
Xiao Wu ◽  
...  

ObjectiveDiabetic cardiomyopathy (DCM) is characterized by cardiac remodeling, dysfunction, and insulin resistance; however, the underlying mechanism has not been fully elucidated. Programmed cell death 4 (PDCD4) is a novel inflammation and apoptosis gene, but its role in type 2 DCM remains elusive. We aimed to determine if PDCD4 intervention improves DCM by affecting left ventricular remodeling, function, and insulin resistance.Research design and methodsWe designed a PDCD4-/- rat, established a type 2 diabetes animal model, and constructed a PDCD4 overexpressed adenovirus and PDCD4 small interfer RNA (siRNA) vectors to alter PDCD4 expression in H9c2 cardiomyocytes. Thereafter, glucose levels, lipid metabolism, echocardiography, and extent of myocardial fibrosis, inflammation, and apoptosis were compared in vivo and in vitro.ResultsPDCD4 deficiency improved insulin resistance, cardiac remodeling, and dysfunction in type 2 DCM rats and improved myocardial hypertrophy, fibrosis, inflammation, and apoptosis. Proliferation and transformation of cardiac fibroblasts was reduced via PDCD4 downregulation in vitro under high-glucose stimulation. Furthermore, PDCD4 regulated the myocardial phosphatidylinositol 3-kinase-protein kinase B (PI3K-AKT) pathway in vivo and in vitro. PDCD4 intervention affected cardiac remodeling, dysfunction, and insulin resistance by influencing fibrosis, inflammation, and apoptosis via the PI3K-AKT pathway in vivo.ConclusionsPDCD4 knockdown protected against left ventricular remodeling, dysfunction, and insulin resistance in type 2 DCM rats. The underlying mechanisms may involve reducing cardiomyocyte apoptosis, inflammation, fibrosis, and normalized PI3K-AKT phosphorylation. To the best of our knowledge, our study is the first to report the effects and underlying mechanisms of PDCD4 in type 2 DCM. These results provide a potential new treatment avenue for improving the prognosis of patients with type 2 DCM.


2011 ◽  
Vol 301 (5) ◽  
pp. C1046-C1056 ◽  
Author(s):  
Serban P. Georgescu ◽  
Mark J. Aronovitz ◽  
Juan L. Iovanna ◽  
Richard D. Patten ◽  
John M. Kyriakis ◽  
...  

Left ventricular remodeling, including the deposition of excess extracellular matrix, is key to the pathogenesis of heart failure. The stress-inducible transcriptional regulator p8 is increased in failing human hearts and is required both for agonist-stimulated cardiomyocyte hypertrophy and for cardiac fibroblasts matrix metalloprotease-9 (MMP9) induction. In the heart, upregulation of autophagy is an adaptive response to stress and plays a causative role in cardiomyopathies. We have recently shown that p8 ablation in cardiac cells upregulates autophagy and that, in vivo, loss of p8 results in a decrease of cardiac function. Here we investigated the effects of p8 genetic deletion in mediating adverse myocardial remodeling. Unstressed p8−/− mouse hearts manifested complex alterations in the expression of fibrosis markers. In addition, these mice displayed elevated autophagy and apoptosis compared with p8+/+ mice. Transverse aortic constriction (TAC) induced left ventricular p8 expression in p8+/+ mice. Pressure overload caused left ventricular remodeling in both genotypes, however, p8−/− mice showed less cardiac fibrosis induction. Consistent with this, although MMP9 induction was attenuated in the p8−/− mice, induction of MMP2 and MMP3 were strikingly upregulated while TIMP2 was downregulated. Left ventricular autophagy increased after TAC and was significantly higher in the p8−/− mice. Thus p8-deletion results in reduced collagen fibrosis after TAC, but in turn, is associated with a detrimental higher increase in autophagy. These findings suggest a role for p8 in regulating in vivo key signaling pathways involved in the pathogenesis of heart failure.


2021 ◽  
Vol 30 ◽  
pp. 096368972098614
Author(s):  
Peng Xia ◽  
Xinwei Wang ◽  
Qi Wang ◽  
Xiaoju Wang ◽  
Qiang Lin ◽  
...  

Mesenchymal stem cell (MSC) migration is promoted by low-intensity pulsed ultrasound (LIPUS), but its mechanism is unclear. Since autophagy is known to regulate cell migration, our study aimed to investigate if LIPUS promotes the migration of MSCs via autophagy regulation. We also aimed to investigate the effects of intra-articular injection of MSCs following LIPUS stimulation on osteoarthritis (OA) cartilage. For the in vitro study, rat bone marrow-derived MSCs were treated with an autophagy inhibitor or agonist, and then they were stimulated by LIPUS. Migration of MSCs was detected by transwell migration assays, and stromal cell-derived factor-1 (SDF-1) and C-X-C chemokine receptor type 4 (CXCR4) protein levels were quantified. For the in vivo study, a rat knee OA model was generated and treated with LIPUS after an intra-articular injection of MSCs with autophagy inhibitor added. The cartilage repair was assessed by histopathological analysis and extracellular matrix protein expression. The in vitro results suggest that LIPUS increased the expression of SDF-1 and CXCR4, and it promoted MSC migration. These effects were inhibited and enhanced by autophagy inhibitor and agonist, respectively. The in vivo results demonstrate that LIPUS significantly enhanced the cartilage repair effects of MSCs on OA, but these effects were blocked by autophagy inhibitor. Our results suggest that the migration of MSCs was enhanced by LIPUS through the activation autophagy, and LIPUS improved the protective effect of MSCs on OA cartilage via autophagy regulation.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Tomohiko Shindo ◽  
Kenta Ito ◽  
Kenichiro Hanawa ◽  
Kentaro Aizawa ◽  
Takashi Shiroto ◽  
...  

Purpose: Despite recent progress in the management of ischemic heart disease (IHD), the number of patients with severe IHD is increasing. In this study, we aimed to develop low-intensity pulsed ultrasound (LIPUS) therapy for the treatment of IHD and to elucidate the underlying molecular mechanisms for the LIPUS-induced angiogenesis. Methods and Results: We first confirmed that the LIPUS up-regulated mRNA expression of vascular endothelial growth factor (VEGF) with a peak at 32-cycle in cultured human vascular endothelial cells (HUVECs). Then, we examined the in vivo effects of LIPUS in a porcine model of chronic myocardial ischemia with reduced left ventricular ejection fraction (LVEF) (n=28). The heart was treated with either sham or LIPUS (32-cycle, 20 min) at 3 different short axis levels (n=14 each). Four weeks after the therapy, LVEF was significantly improved in the LIPUS group (46±4 to 57±5%, P<0.05), whereas it remained unchanged in the control group. Capillary density and regional myocardial blood flow in the ischemic region were also increased in the LIPUS group but not in the control group. The protein expressions of VEGF, eNOS and bFGF in the ischemic area were enhanced in the LIPUS group compared with the control group. To further examine the signaling pathways responsible for the LIPUS-induced angiogenesis, HUVECs were transfected with siRNA or scrambled siRNA of either β1 integrin or caveolin-1. Knockdown of either β1 integrin or caveolin-1 with siRNA suppressed the LIPUS-induced up-regulation of VEGF. siRNA-mediated suppression of either focal adhesion kinase (FAK) or Fyn also inhibited the LIPUS-induced up-regulation of VEGF. Knockdown of these molecules with siRNA was confirmed with real-time PCR. Conclusions: These results suggest that the LIPUS therapy is promising as a new, non-invasive therapy for IHD and that β1 integrin and caveolin-1 may be involved in underlying molecular mechanisms for the beneficial effects of the LIPUS.


2018 ◽  
Vol 132 (6) ◽  
pp. 685-699 ◽  
Author(s):  
Zhen-Guo Ma ◽  
Xin Zhang ◽  
Yu-Pei Yuan ◽  
Ya-Ge Jin ◽  
Ning Li ◽  
...  

T-cell infiltration and the subsequent increased intracardial chronic inflammation play crucial roles in the development of cardiac hypertrophy and heart failure (HF). A77 1726, the active metabolite of leflunomide, has been reported to have powerful anti-inflammatory and T cell-inhibiting properties. However, the effect of A77 1726 on cardiac hypertrophy remains completely unknown. Herein, we found that A77 1726 treatment attenuated pressure overload or angiotensin II (Ang II)-induced cardiac hypertrophy in vivo, as well as agonist-induced hypertrophic response of cardiomyocytes in vitro. In addition, we showed that A77 1726 administration prevented induction of cardiac fibrosis by inhibiting cardiac fibroblast (CF) transformation into myofibroblast. Surprisingly, we found that the protective effect of A77 1726 was not dependent on its T lymphocyte-inhibiting property. A77 1726 suppressed the activation of protein kinase B (AKT) signaling pathway, and overexpression of constitutively active AKT completely abolished A77 1726-mediated cardioprotective effects in vivo and in vitro. Pretreatment with siRNA targetting Fyn (si Fyn) blunted the protective effect elicited by A77 1726 in vitro. More importantly, A77 1726 was capable of blocking pre-established cardiac hypertrophy in mice. In conclusion, A77 1726 attenuated cardiac hypertrophy and cardiac fibrosis via inhibiting FYN/AKT signaling pathway.


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