scholarly journals Neutrophil Elastase Deficiency Ameliorates Myocardial Injury Post Myocardial Infarction in Mice

2021 ◽  
Vol 22 (2) ◽  
pp. 722
Author(s):  
Yukino Ogura ◽  
Kazuko Tajiri ◽  
Nobuyuki Murakoshi ◽  
DongZhu Xu ◽  
Saori Yonebayashi ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Neutrophil Elastase ◽  
Myocardial Injury ◽  
Flow Cytometric Analysis ◽  
Akt Signaling ◽  
Border Zone ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Deficient Mice

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.

scholarly journals MicroRNA-322-5p Protects Against Myocardial Infarction through Targeting BTG2

2021 ◽  
Author(s):  
Yang Ruan ◽  
Shuai Meng ◽  
Ruofei Jia ◽  
Xiaojing Cao ◽  
zening Jin
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
B Cell ◽  
Rat Model ◽  
Myocardial Injury ◽  
Pathological Condition ◽  
Current Paper ◽  
Targeted Treatment ◽  
Myocardial Tissue

Abstract Objective: A large cohort of studies have addressed the therapeutic importance of microRNA (miR) in the treatment of myocardial infarction (MI). The current paper gives prominence to the role of miR-322-5p in MI by regulating B-cell translocation gene 2 (BTG2).Methods: In a rat model of MI miR-322-5p and BTG2 expression was estimated. Adenovirus that altered miR-322-5p or BTG2 expression was injected into MI rats. After that, cardiac function, inflammation, myocardial injury, pathological condition, apoptosis, and the NF-κB pathway-related genes in the myocardial tissue of MI rats after targeted treatment were evaluated. The targeting relationship between miR-322-5p and BTG2 was assessed.Results: miR-322-5p was lowly expressed and BTG2 was highly expressed in the myocardial tissue of MI rats. Restored miR-322-5p improved cardiac function, relived inflammation and myocardial injury, suppressed pathological condition and apoptosis and inactivated NF-κB pathway in MI rats. BTG2 expression was negatively mediated by miR-322-5p. Overexpressed BTG2 rescued miR-322-5p-induced cardioprotection on MI rats.Conclusion: It is evident that miR-322-5p protects against MI through suppressing BTG2 expression.

scholarly journals MiR-34a Protects Mesenchymal Stem Cells From Hyperglycaemic Injury Through The Activation of The Sirt1/FoxO3a Autophagy Pathway

2020 ◽  
Author(s):  
Fengyun Zhang ◽  
Fei Gao ◽  
Kun Wang ◽  
Xiaohong Liu ◽  
Zhuoqi Zhang
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Cardiac Function ◽  
Cell Viability ◽  
High Glucose ◽  
Border Zone ◽  
Autophagy Pathway ◽  
Precise Role

Abstract BackgroundAutologous mesenchymal stem cells (MSCs) are favourable treatments for ischaemic diseases; however, MSCs from diabetic patients are not useful for this purpose. Recent studies have shown that the expression of miR-34a is significantly increased in patients with hyperglycaemia, the precise role of miR-34a in MSCs in diabetes need to be clarified.ObjectiveThe aim of this study is to determine the precise role of miR-34a in MSCs exposed to hyperglycaemia and in healing the heart after myocardial infarction in diabetes mellitus (DM) rats.MethodsDM rats were established by STZ injection. MSCs were isolated from the bone marrow of donor rats. Chronic culture of MSCs under high glucose was used to mimic the DM microenvironment. The role of miR-34a in regulating cell viability, senescence and paracrine effects were investigated using a cell counting kit-8 (CCK-8) assay, senescence-associated β-galactosidase (SA-β-gal) staining, and VEGF and bFGF ELISA, respectively. The expression of autophagy- and senescence-associated proteins in MSCs and silent information regulator 1 (SIRT1) and forkhead box class O 3a (FOXO3a) were analysed by western blotting. Autophagic bodies were analysed by transmission electron microscopy (TEM). The MI model was established by left anterior descending coronary artery (LAD) ligation, and then the mice were transplanted with differentially treated MSCs intramuscularly at sites around the border zone of the infarcted heart. Thereafter, cardiac function in mice in each group was detected via cardiac ultrasonography at 1 week and 3 weeks after surgery. The infarct size was determined through a 2,3,5-triphenyltetrazolium chloride (TTC) staining assay, while myocardial fibrosis was assessed by Masson staining.ResultsThe results of the current study showed that miR-34a was significantly upregulated under chronic hyperglycaemia exposure. Overexpression of miR-34a was significantly associated with impaired cell viability, exacerbated senescence and disrupted cell paracrine capacity. Moreover, we found that the mechanism underlying miR-34a-mediated deterioration of MSCs exposed to high glucose involves the activation of the Sirt1/Foxo3a autophagy pathway. Further analysis showed that miR-34a inhibitor-treated MSC transplantation could improve cardiac function and decrease the scar area in DM rats.ConclusionsOur study demonstrates for the first time that miR-34a mediates the deterioration of MSC functions under hyperglycaemia. The underlying mechanism may involve the Sirt1/Foxo3a autophagy signalling pathway. Thus, inhibition of miR-34a might have important therapeutic implications in MSC-based therapies for myocardial infarction in DM patients.

scholarly journals Upregulated microRNA-210-3p Improves Sevoflurane-induced Protective Effect on Ventricular Remodeling in Rats With Myocardial Infarction by Inhibiting ADCY9

2021 ◽  
Author(s):  
Yahui Wu ◽  
Taofu Wang ◽  
Liang Qiao ◽  
Hongqi Lin
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Protective Effect ◽  
Adenylyl Cyclase ◽  
Cause Of Death ◽  
Myocardial Injury ◽  
Ventricular Remodeling ◽  
Cardiomyocyte Apoptosis

Abstract ObjectiveMyocardial infarction (MI) is a significant cause of death and disability, and sevoflurane (sevo) can protect myocardium in clinic. We aim to assess the effects of miR-210-3p on MI rats undergoing sevo treatment with the involvement of adenylyl cyclase type 9 (ADCY9).MethodsRat MI models were constructed by ligation of the left anterior descending and the modeled mice were respectively treated with sevo, miR-210-3p agomir/antagomir or overexpressed ADCY9. Then, miR-210-3p and ADCY9 expression, cardiac function, myocardial injury and fibrosis, and cardiomyocyte apoptosis in rats were evaluated. Target relation between miR-210-3p and ADCY9 was detected.ResultsMiR-210-3p was downregulated while ADCY9 was upregulated in MI rats. Sevo was able to promote cardiac function and attenuate myocardial injury and fibrosis, as well as cardiomyocyte apoptosis in MI rats. These effects of sevo were strengthened by miR-210-3p elevation while abolished by miR-210-3p inhibition. The role of elevated miR-210-3p in MI rats was reversed by overexpression of ADCY9.ConclusionUpregulated miR-210-3p improves sevo-induced protective effect on ventricular remodeling in rats with MI through inhibiting ADCY9.

Abstract P199: Mas Receptor Deficiency Regulates Obesity-Hypertension and Cardiac Function in Female and Male Mice

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Robin C Shoemaker ◽  
Yu Wang ◽  
Sean Thatcher ◽  
Lisa Cassis
Keyword(s):  
Blood Pressure ◽  
Sexual Dimorphism ◽  
Cardiac Function ◽  
Male Mice ◽  
Reduced Ejection Fraction ◽  
Obesity Hypertension ◽  
Obese Male ◽  
Deficient Mice ◽  
Cmr Imaging

Angiotensin-1-7 (Ang-(1-7)) counteracts angiotensin II through effects at Mas receptors (MasR). We demonstrated that sexual dimorphism of obesity-hypertension was associated with dysregulated production of Ang-(1-7). However, the role of MasR in sexual dimorphism of obesity-hypertension has not been examined. MasR deficient mice have also been reported to exhibit deficits in cardiac function. In this study, we hypothesized that deficiency of the MasR would differentially regulate obesity-hypertension in male versus ( vs ) female mice. In addition, we quantified effects of MasR deficiency on cardiac function in obese male mice. Male and female MasR +/+ and -/- mice were fed a low fat (LF, 10%kcal) or high fat (HF, 60% kcal) diet for 16 weeks, and blood pressure was quantified by radiotelemetry. As demonstrated previously, male MasR +/+ mice (24 hr diastolic blood pressure, DBP: LF, 90 ± 3; HF, 96 ± 2 mmHg; P<0.05), but not females (LF, 85 ± 1; HF, 85 ± 2 mmHg), developed hypertension in response to HF feeding. MasR deficiency converted female HF-fed mice to an obesity-hypertension phenotype (DBP: 92 ± 1 mmHg; P<0.05). Surprisingly, male HF-fed MasR -/- mice exhibited reduced DBP compared to HF-fed MasR +/+ males (90 ± 1 vs 96 ± 2 mmHg; P<0.05). To define mechanisms for reductions in DBP of HF-fed male MasR -/- mice, we performed cardiac magnetic resonance (CMR) imaging in both genotypes at 1 month of HF feeding. MasR -/- mice had significantly reduced ejection fraction (EF) compared to MasR +/+ mice at baseline (51.4 ± 2.5 vs 59.3 ± 2.1%; P<0.05) and after one month of HF-feeding (49.8 ± 2.4 vs 52.6 ± 1.9%; P<0.05). Further, CMR imaging demonstrated a thickening of the ventricle wall in MasR -/- mice with 1 month of HF-feeding. MasR +/+ , but not MasR -/- mice, exhibited diet-induced reductions in EF (by 16%; P<0.05) at 1 month of HF feeding, which were reversed by infusion of Ang-(1-7). These results demonstrate that MasR contributes to sexual dimorphism of obesity-hypertension. Ang-(1-7) protects females from obesity-hypertension through the MasR. In contrast, reductions in DBP in obese male mice with MasR deficiency may arise from deficits in cardiac function. These results suggest that MasR agonists may be effective therapies for obesity-associated cardiovascular conditions.

scholarly journals Mesenchymal stem cells with overexpression of Angiotensin-converting enzyme-2 improved the microenvironment and cardiac function in a rat model of myocardial infarction

2020 ◽  
Author(s):  
Chao Liu ◽  
Yue Fan ◽  
Hong-Yi Zhu ◽  
Lu zhou ◽  
Yu Wang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Angiotensin Converting Enzyme ◽  
Cardiac Function ◽  
Heart Function ◽  
Tube Formation ◽  
Border Zone ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2

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.

scholarly journals Garcinoic Acid Improves Cardiac Function and Enhances Angiogenesis Following Myocardial Infarction

2021 ◽  
Author(s):  
Hongyao Hu ◽  
Wei Li ◽  
Yanzhao Wei ◽  
Hui Zhao ◽  
Zhenzhong Wu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Ventricular Remodeling ◽  
Vehicle Group ◽  
Potential Mechanism ◽  
Garcinia Kola ◽  
Angiogenic Proteins

Abstract Cardiac ischemia impairs angiogenesis in response to hypoxia, resulting in ventricular remodeling. Garcinoic acid (GA), the extraction from the plant garcinia kola, is validated to attenuate inflammatory response. However, the role of GA in heart failure (HF) and neovascularization after myocardial infarction (MI) is incompletely understood. The present study is striving to explore the role of GA and the potential mechanism of which in cardiac function after MI. SD rats were randomized into sham group, MI+vehicle group, and MI+GA group in vivo. Human umbilical endothelial cells (HUVECs) were cultured in vehicle or GA, and then additionally exposed to 2% hypoxia environment in vitro. MI rats displayed a dramatically reduced myocardial injury, cardiac function and vessel density in the peri-infarcted areas. GA delivery markedly improved cardiac performance and promoted angiogenesis. In addition, GA significantly enhanced tube formation in HUVECs under hypoxia condition. Furthermore, the expressions of pro-angiogenic factors HIF-1α, VEGF-A and bFGF, and pro-angiogenic proteins phospho-VEGFR2Tyr1175 and VEGFR2, as well as phosphorylation levels of Akt and eNOS were increased by GA treatment. In conclusion, GA preserved cardiac function after MI probably via promoting neovascularization. And the potential mechanism may be partially through upregulating the expressions of HIF-1α, VEGF-A, bFGF, phospho-VEGFR2Tyr1175 and VEGFR2 and activating the phosphorylations of Akt and eNOS.

Abstract 145: Apelin Reduces Myocardial Infarction Size and Promotes Angiogenesis by Increasing SDF-1/CXCR4 and AKT/eNOS/VEGF Pathways

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Lanfang Li ◽  
Heng Zeng ◽  
Jian-xiong Chen
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Ischemia ◽  
Molecular Mechanisms ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Border Zone ◽  
Heart Weight ◽  
Tunel Staining ◽  
Myocardial Infarct Size

Background: Apelin is an endogenous ligand for the angiotensin-like 1 receptor (APJ) and is emerging as a key player in the regulation of angiogenesis as well as ischemia/reperfusion injury. So far, little is known about the functional role of apelin in myocardial ischemia. We investigated the potential intracellular molecular mechanisms and protective role of apelin during myocardial ischemic injury. Methods and Results: Myocardial ischemia was achieved by ligation of the left anterior descending coronary artery (LAD) for 24 hours and 14 days. Myocardial apoptosis was detected by TUNEL staining. Akt, endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), SDF-1 and CXCR4 expression were measured by western blot. The CD133+/cKit+/Sca1+, CD133/SDF-1+ and cKit/CXCR4+ cells were determined by immunostaining. Myocardial capillary and arteriole densities were analyzed in the border zone of infarcted myocardium at 14 d of ischemia. Treatment of C57BL/6J mice with apelin-13 (1 mg/Kg.d) by i.p. injection for 3 days before surgery results in significant decreases in TUNEL positive cells and myocardial infarct size at 24 hours of ischemia. Treatment with apelin increases the phosphorylation of AKT and eNOS and upregulates VEGF expression in the ischemic heart. Furthermore, treatment with apelin leads to the expression of SDF-1 and CXCR4 and increases in the number of CD133+/cKit+/Sca1+, CD133/SDF-1+ and cKit/CXCR4+ cells in ischemic hearts. Treatment with apelin also significantly increases myocardial capillary densities and arteriole formation together with a significant decrease in the ratio of heart weight to body weight at 14 days of ischemia. This is accompanied by a significant improvement of cardiac function after 14 days of ischemia. Conclusions: Our data demonstrate that apelin contributes to the protection of myocardial infarction and angiogenesis by the mechanisms involving in upregulation of SDF-1/CXCR4 and AKT/eNOS/VEGF pathways.

Abstract 2879: Targeted and Tailored: A New Approach to Regeneration after a Myocardial Infarction

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Hiroko Fujii ◽  
Shu-Hong Li ◽  
Yasuo Miyagi ◽  
Shafie Fazel ◽  
Terrence M Yau ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Myocardial Perfusion ◽  
Cardiac Function ◽  
Border Zone ◽  
Control Group ◽  
Vascular Density ◽  
Coronary Artery Ligation ◽  
New Approach ◽  
Cell Counts ◽  
Targeted Ultrasound

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.

Abstract 342: Cortical Bone Stem Cell Therapy Alters Macrophage Phenotype and Reduces Cardiac Cell Death After Myocardial Infarction

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Alexander R Hoachlandr-Hobby ◽  
Remus M Berretta ◽  
Yijun Yang ◽  
Eric Feldsott ◽  
Hajime Kubo ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Immune Response ◽  
Infarct Size ◽  
Reperfusion Injury ◽  
Cortical Bone ◽  
Myocardial Injury ◽  
Border Zone ◽  
Paracrine Factors ◽  
Infarct Border Zone ◽  
Infarct Border

Acute injuries to the heart, like myocardial infarction (MI), contribute to the development and pathology of heart failure (HF). Reperfusion of the ischemic heart greatly increases survival but results in reperfusion injury that can account for up to 50% of the final infarct size. The inflammatory response to MI-induced myocardial injury is thought to be responsible for the propagation of reperfusion injury into the infarct border zone, expanding myocardial damage. We have previously shown in a swine model of MI that intramyocardial injections of cortical bone-derived stem cells (CBSCs) into the infarct border zone has no acute cardioprotective effect but reduces scar size by half and prevents the decline of ejection fraction and LV dilation 3 months after MI. Our new preliminary data show that CBSCs have potent immunoregulatory capabilities. Therefore, we hypothesize that CBSC treatment has an effect on the immune response to MI that improves the wound healing response to myocardial injury and mitigates LV remodeling and infarct size 3 months later. To test this hypothesis, we characterized the effects of CBSC paracrine factors on macrophages in vitro and found that CBSC-treated macrophages express higher levels of CD206, produce more IL-1RA and IL-10, and phagocytose apoptotic myocytes more efficiently. In addition, macrophages were increased in CBSC-treated swine hearts 7 days after MI compared to controls with a corresponding increase in IL-1RA and TIMP-2. Apoptosis was decreased overall and in macrophages specifically in CBSC-treated animals. From these data we conclude CBSCs may exert an acute pro-reparative effect on the immune response after MI, reducing reperfusion injury and adverse remodeling resulting in improved functional outcomes at later time points.

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