Butyrate improves cardiac function and sympathetic neural remodeling following myocardial infarction in rats

2020 ◽  
Vol 98 (6) ◽  
pp. 391-399
Author(s):  
Xiaojie Jiang ◽  
Xin Huang ◽  
Yifan Tong ◽  
Hong Gao

Increased inflammation is found in cardiac sympathetic neural remodeling with malignant ventricular arrhythmia (VA) following myocardial infarction (MI). Butyrate, as a microbiota-derived short-chain fatty acid, can inhibit inflammation and myocardial hypertrophy. However, the role of butyrate in sympathetic neural remodeling after MI is unknown. This study aimed to investigate whether butyrate could improve cardiac dysfunction and VA following MI by regulating inflammation and sympathetic neural remodeling. MI rats were randomized to administrate the butyrate or vehicle through intraperitoneal injection to undergo the study. Our data demonstrated that butyrate treatment preserved the partial cardiac function at 7 days post-MI. Butyrate downregulated the expression of essential for inflammatory response in the infarct border zone at 3 days post-MI. Particularly, butyrate promoted expression of M2 macrophage markers. Increased expressions of nerve growth factor and norephinephrine at 7 days after MI were inhibited in butyrate-treated rats. Furthermore, butyrate significantly decreased the density of nerve fibers for growth-associated protein-43 and tyrosine hydroxylase and resulted in fewer episodes of inducible VA. In conclusion, butyrate administration ameliorated cardiac function and VA after MI possibly through promoting M2 macrophage polarization to suppress inflammatory responses and inhibit sympathetic neural remodeling and may present an effective pharmacological strategy for the prevention of MI-related remodeling.

2022 ◽  
Vol 8 ◽  
Author(s):  
Zhi Li ◽  
Miao Nie ◽  
Liming Yu ◽  
Dengshun Tao ◽  
Qiang Wang ◽  
...  

Myocardial infarction (MI) is regarded as a serious ischemic heart disease on a global level. The current study set out to explore the mechanism of the Notch signaling pathway in the regulation of fibrosis remodeling after the occurrence of MI. First, experimental mice were infected with recombination signal binding protein J (RBP-J) shRNA and empty adenovirus vector, followed by the establishment of MI mouse models and detection of cardiac function. After 4 weeks of MI, mice in the sh-RBP-J group were found to exhibit significantly improved cardiac function relative to the sh-NC group. Moreover, knockdown of RBP-J brought about decreased infarct area, promoted cardiac macrophages M2 polarization, reduced cardiac fibrosis, and further decreased transcription and protein expressions of inflammatory factors and fibrosis-related factors. Furthermore, downregulation of cylindromatosis (CYLD) using si-CYLD reversed the results that knockdown of RBP-J inhibited fibrogenesis and the release of inflammatory factors. Altogether, our findings indicated that the blockade of Notch signaling promotes M2 polarization of cardiac macrophages and improves cardiac function by inhibiting the imbalance of fibrotic remodeling after MI.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Peisen Huang ◽  
Li Wang ◽  
Qing Li ◽  
Jun Xu ◽  
Junyan Xu ◽  
...  

Abstract Background Bone marrow mesenchymal stem cells (MSCs) are among the most common cell types to be used and studied for cardiac regeneration. Low survival rate and difficult retention of delivered MSCs in infarcted heart remain as major challenges in the field. Co-delivery of stem cell-derived exosomes (Exo) is expected to improve the recruitment and survival of transplanted MSCs. Methods Exo was isolated from MSCs and delivered to an acute myocardial infarction (AMI) rat heart through intramyocardial injection with or without intravenous infusion of atrovastatin-pretreated MSCs on day 1, day 3, or day 7 after infarction. Echocardiography was performed to evaluate cardiac function. Histological analysis and ELISA test were performed to assess angiogenesis, SDF-1, and inflammatory factor expression in the infarct border zone. The anti-apoptosis effect of Exo on MSCs was evaluated using flow cytometry and Hoechst 33342 staining assay. Results We found that intramyocardial delivery of Exo followed by MSC transplantation (in brief, Exo+MSC treatment) into MI hearts further improved cardiac function, reduced infarct size, and increased neovascularization when compared to controls treated with Exo or MSCs alone. Of note, comparing the three co-transplanting groups, intramyocardially injecting Exo 30 min after AMI combined with MSCs transplantation at day 3 after AMI achieved the highest improvement in heart function. The observed enhanced heart function is likely due to an improved microenvironment via Exo injection, which is exemplified as reduced inflammatory responses and better MSC recruitment and retention. Furthermore, we demonstrated that pre-transplantation injection of Exo enhanced survival of MSCs and reduced their apoptosis both in vitro and in vivo. Conclusions Combinatorial delivery of exosomes and stem cells in a sequential manner effectively reduces scar size and restores heart function after AMI. This approach may represent as an alternative promising strategy for stem cell-based heart repair and therapy.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jialiang Zhang ◽  
Fangyang Huang ◽  
Li Chen ◽  
Guoyong Li ◽  
Wenhua Lei ◽  
...  

Background. After myocardial infarction, anti-inflammatory macrophages perform key homeostatic functions that facilitate cardiac recovery and remodeling. Several studies have shown that lactate may serve as a modifier that influences phenotype of macrophage. However, the therapeutic role of sodium lactate in myocardial infarction (MI) is unclear. Methods. MI was established by permanent ligation of the left anterior descending coronary artery followed by injection of saline or sodium lactate. Cardiac function was assessed by echocardiography. The cardiac fibrosis area was assessed by Masson trichrome staining. Macrophage phenotype was detected via qPCR, flow cytometry, and immunofluorescence. Signaling proteins were measured by Western blotting. Results. Sodium lactate treatment following MI improved cardiac performance, enhanced anti-inflammatory macrophage proportion, reduced cardiac myocytes apoptosis, and increased neovascularization. Flow-cytometric analysis results reported that sodium lactate repressed the number of the IL-6+, IL-12+, and TNF-α+ macrophages among LPS-stimulated bone marrow-derived macrophages (BMDMs) and increased the mRNA levels of Arg-1, YM1, TGF-β, and IL-10. Mechanistic studies revealed that sodium lactate enhanced the expression of P-STAT3. Furthermore, a STAT3 inhibitor eliminated sodium lactate-mediated promotion macrophage polarization. Conclusion. Sodium lactate facilitates anti-inflammatory M2 macrophage polarization and protects against MI by regulating P-STAT3.


2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Xiaotian Zhang ◽  
Di Zhu ◽  
Liping Wei ◽  
Zhijing Zhao ◽  
Xin Qi ◽  
...  

Oncostatin M (OSM) has been reported to stimulate angiogenesis by upregulating VEGF and bFGF, implying that it could be a therapeutic strategy in treating ischemic diseases. The present study was aimed at investigating whether OSM could improve cardiac function via prompting angiogenesis following myocardial infarction (MI). Wild type (WT) and Oβknock-out (Oβ−/−) mice were, respectively, randomized into sham group, MI + vehicle group, and MI + OSM group. WT mice displayed significantly impaired cardiac function after MI. OSM treatment attenuated cardiac dysfunction in WT MI mice, while Oβdeletion abrogated the protective effects. Besides, OSM attenuated heart hypertrophy and pulmonary congestion evidenced by decreased heart weight/body weight and lung weight/body weight ratio. Further, reduction of apoptosis and fibrosis in infarct border zone was observed in OSM treated WT MI mice compared with vehicle. Moreover, in WT mice subjected to MI, OSM treatment significantly increased capillary density along with upregulation of p-Akt and angiogenic factors VEGF and bFGF in comparison with vehicle, and this phenomenon was not found in Oβ−/−mice. In conclusion, OSM treatment preserved cardiac function, inhibited apoptosis and fibrosis, and stimulated angiogenesis via upregulating VEGF and bFGF in infarct border zone of ischemic myocardium, indicating that OSM could be a novel therapeutic target for MI.


Author(s):  
Eunhwa Seong ◽  
Jun‐Ho Lee ◽  
Sungmin Lim ◽  
Eun‐Hye Park ◽  
Eunmin Kim ◽  
...  

Background The immune and inflammatory responses play a considerable role in left ventricular remodeling after myocardial infarction (MI). Binding of AhR (aryl hydrocarbon receptor) to its ligands modulates immune and inflammatory responses; however, the effects of AhR in the context of MI are unknown. Therefore, we evaluated the potential association between AhR and MI by treating mice with a nontoxic endogenous AhR ligand, ITE (2‐[1’H‐indole‐3’‐carbonyl]‐thiazole‐4‐carboxylic acid methyl ester). We hypothesized that activation of AhR by ITE in MI mice would boost regulatory T‐cell differentiation, modulate macrophage activity, and facilitate infarct healing. Methods and Results Acute MI was induced in C57BL/6 mice by ligation of the left anterior descending coronary artery. Then, the mice were randomized to daily intraperitoneal injection of ITE (200 µg/mouse, n=19) or vehicle (n=16) to examine the therapeutic effects of ITE during the postinfarct healing process. Echocardiographic and histopathological analyses revealed that ITE‐treated mice exhibited significantly improved systolic function ( P <0.001) and reduced infarct size compared with control mice ( P <0.001). In addition, we found that ITE increased regulatory T cells in the mediastinal lymph node, spleen, and infarcted myocardium, and shifted the M1/M2 macrophage balance toward the M2 phenotype in vivo, which plays vital roles in the induction and resolution of inflammation after acute MI. In vitro, ITE expanded the Foxp3 + (forkhead box protein P3‐positive) regulatory T cells and tolerogenic dendritic cell populations. Conclusions Activation of AhR by a nontoxic endogenous ligand, ITE, improves cardiac function after MI. Post‐MI mice treated with ITE have a significantly lower risk of developing advanced left ventricular systolic dysfunction than nontreated mice. Thus, the results imply that ITE has a potential as a stimulator of cardiac repair after MI to prevent heart failure.


Author(s):  
Yuting Tang ◽  
Xiaofang Lin ◽  
Cheng Chen ◽  
Zhongyi Tong ◽  
Hui Sun ◽  
...  

Background: Nucleolin has multiple functions within cell survival and proliferation pathways. Our previous studies have revealed that nucleolin can significantly reduce myocardial ischemia-reperfusion injury by promoting myocardial angiogenesis and reducing myocardial apoptosis. In this study, we attempted to determine the role of nucleolin in myocardial infarction (MI) injury recovery and the underlying mechanism. Methods: Male BALB/c mice aged 6–8 weeks were used to set up MI models by ligating the left anterior descending coronary artery. Nucleolin expression in the heart was downregulated by intramyocardial injection of a lentiviral vector expressing nucleolin-specific small interfering RNA. Macrophage infiltration and polarization were measured by real-time polymerase chain reaction, flow cytometry, and immunofluorescence. Cytokines were detected by enzyme-linked immunosorbent assay. Results: Nucleolin expression in myocardium after MI induction decreased a lot at early phase and elevated at late phase. Nucleolin knockdown impaired heart systolic and diastolic functions and decreased the survival rate after MI. Macrophage infiltration increased in the myocardium after MI. Most macrophages belonged to the M1 phenotype at early phase (2 days) and the M2 phenotype increased greatly at late phase after MI. Nucleolin knockdown in the myocardium led to a decrease in M2 macrophage polarization with no effect on macrophage infiltration after MI. Furthermore, Notch3 and STAT6, key regulators of M2 macrophage polarization, were upregulated by nucleolin in RAW 264.7 macrophages. Conclusions: Lack of nucleolin impaired heart function during recovery after MI by reducing M2 macrophage polarization. This finding probably points to a new therapeutic option for ischemic heart disease.


2021 ◽  
Vol 22 (2) ◽  
pp. 722
Author(s):  
Yukino Ogura ◽  
Kazuko Tajiri ◽  
Nobuyuki Murakoshi ◽  
DongZhu Xu ◽  
Saori Yonebayashi ◽  
...  

Neutrophils are recruited into the heart at an early stage following a myocardial infarction (MI). These secrete several proteases, one of them being neutrophil elastase (NE), which promotes inflammatory responses in several disease models. It has been shown that there is an increase in NE activity in patients with MI; however, the role of NE in MI remains unclear. Therefore, the present study aimed to investigate the role of NE in the pathogenesis of MI in mice. NE expression peaked on day 1 in the infarcted hearts. In addition, NE deficiency improved survival and cardiac function post-MI, limiting fibrosis in the noninfarcted myocardium. Sivelestat, an NE inhibitor, also improved survival and cardiac function post-MI. Flow cytometric analysis showed that the numbers of heart-infiltrating neutrophils and inflammatory macrophages (CD11b+F4/80+CD206low cells) were significantly lower in NE-deficient mice than in wild-type (WT) mice. At the border zone between intact and necrotic areas, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells was lower in NE-deficient mice than in WT mice. Western blot analyses revealed that the expression levels of insulin receptor substrate 1 and phosphorylation of Akt were significantly upregulated in NE-knockout mouse hearts, indicating that NE deficiency might improve cardiac survival by upregulating insulin/Akt signaling post-MI. Thus, NE may enhance myocardial injury by inducing an excessive inflammatory response and suppressing Akt signaling in cardiomyocytes. Inhibition of NE might serve as a novel therapeutic target in the treatment of MI.


2020 ◽  
Author(s):  
Chao Liu ◽  
Yue Fan ◽  
Hong-Yi Zhu ◽  
Lu zhou ◽  
Yu Wang ◽  
...  

AbstractBackgroundAngiotensin-converting enzyme-2 (ACE2) overexpression improves left ventricular remodeling and function in diabetic cardiomyopathy; however, the effect of ACE2-overexpressed mesenchymal stem cells (MSCs) on myocardial infarction (MI) remains unexplored. This study aimed to investigate the effect of ACE2-overexpression on the function of MSCs and the therapeutic efficacy of MSCs for MI.MethodsMSCs were transfected with Ace2 gene using lentivirus, and then transplanted into the border zone of ischemic heart. The renin-angiotensin system (RAS) expression, nitric oxide synthase (NOS) expression, paracrine factors, anti-hypoxia ability, tube formation of MSCs, and heart function were determined.ResultsMSCs expressed little ACE2. ACE2-overexpression decreased the expression of AT1 and VEGF apparently, up-regulated the paracrine of HGF, and increased the synthesis of Angiotensin 1-7 in vitro. ACE2-overexpressed MSCs showed a cytoprotective effect on cardiomyocyte, and an interesting tube formation ability, decreased the heart fibrosis and infarct size, and improved the heart function.ConclusionTherapies employing MSCs with ACE2 overexpression may represent an effective treatment for improving the myocardium microenvironment and the cardiac function after MI.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Hiroko Fujii ◽  
Shu-Hong Li ◽  
Yasuo Miyagi ◽  
Shafie Fazel ◽  
Terrence M Yau ◽  
...  

Rationale: Targeted: Ultrasound targeted microbubble destruction (UTMD) delivers genes directly to the injured myocardium. Tailored: UTMD could permit recurrent treatment until recovery is complete. Hypothesis: Repeated UTMD is a novel strategy to induce tissue regeneration and improve ventricular function after a myocardial infarction. Methods: Microbubbles were mixed with plasmids containing stem cell factor (SCF) and stromal cell-derived factor (SDF)-1α genes. Seven days after coronary artery ligation, adult rats underwent UTMD either 1, 3 or 6 times at 2-day intervals in 4 randomly assigned groups: Control group: 6 UTMD treatments with empty plasmid (n=4); Repeat 1 (n=6), Repeat 3 (n=7), Repeat 6 (n=6) groups: 1, 3 or 6 treatments, respectively, of UTMD with SCF and SDF-1α plasmid DNA. Cardiac function (echocardiography) and myocardial perfusion (myocardial contrast echocardiography) were assessed on days 0, 10 and 24 after the first treatment. Biochemical assessments were performed on day 24. Results: Cardiac function was highest in the Repeat 6 group (p<0.05 vs. Repeat 1). Myocardial SCF levels were higher after multiple rather than single UTMD treatments (p<0.05 for Repeat 3 and Repeat 6 vs. Repeat 1), with the highest levels in the Repeat 6 group (p<0.05 vs. Repeat 3). Myocardial SDF-1α levels and c-kit-positive cell counts also increased with the maximum number of treatments (p<0.05 for Repeat 6 vs. Repeat 1). Myocardial CXCR4-positive cells were more numerous in the remote regions of both multiple UTMD groups (p<0.05 for Repeat 3 and Repeat 6 vs. Repeat 1). Both myocardial perfusion in the infarct region and vascular density (Factor VIII or alpha-smooth muscle actin staining) in the border zone increased with repeated treatments (p<0.05 for Repeat 3 and Repeat 6 vs. Repeat 1), with an additional increase in the Repeat 6 group (p<0.01 vs. Repeat 3). Conclusions: Targeted ultrasound delivery of SCF and SDF-1α genes to the myocardium induced angiogenesis, recruited progenitor cells and improved cardiac function. Multiple UTMD treatments further enhanced regeneration. Tailoring the treatment by providing the number of interventions required to restore function provides a new approach to cardiac regeneration following a myocardial infarction.


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