scholarly journals OSM Enhances Angiogenesis and Improves Cardiac Function after Myocardial Infarction

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Xiaotian Zhang ◽  
Di Zhu ◽  
Liping Wei ◽  
Zhijing Zhao ◽  
Xin Qi ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Body Weight ◽  
Cardiac Function ◽  
Weight Ratio ◽  
Oncostatin M ◽  
Border Zone ◽  
Heart Weight ◽  
Vehicle Group ◽  
Infarct Border Zone ◽  
Infarct Border

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.

Cardiac-specific ablation of theSTAT3gene in the subacute phase of myocardial infarction exacerbated cardiac remodeling

2015 ◽  
Vol 309 (3) ◽  
pp. H471-H480 ◽  
Author(s):  
Daichi Enomoto ◽  
Masanori Obana ◽  
Akimitsu Miyawaki ◽  
Makiko Maeda ◽  
Hiroyuki Nakayama ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Remodeling ◽  
Cardiac Fibrosis ◽  
Biological Significance ◽  
Weight Ratio ◽  
Fluorescence Analysis ◽  
Border Zone ◽  
Intrinsic Activity ◽  
Heart Weight ◽  
Subacute Phase

STAT3 is a cardioprotective molecule against acute myocardial injury; however, recent studies have suggested that chronic STAT3 activation in genetically modified mice was detrimental after myocardial infarction (MI). In the present study, we assessed the biological significance of STAT3 activity in subacute MI using tamoxifen (TM)-inducible cardiac-specific STAT3 knockout (STAT3 iCKO) mice. After coronary ligation, STAT3 was rapidly activated in hearts, and its activation was sustained to the subacute phase. To make clear the pathophysiological roles of STAT3 activation specifically in subacute MI, MI was generated in STAT3 iCKO mice followed by TM treatment for 14 consecutive days beginning from day 11 after MI, which ablated the STAT3 gene in the subacute phase. Intriguingly, mortality was increased by TM treatment in STAT3 iCKO mice, accompanied by an increased heart weight-to-body weight ratio. Masson's trichrome staining demonstrated that cardiac fibrosis was dramatically exacerbated in STAT3 iCKO mice 24 days after MI (fibrotic circumference: 58.3 ± 6.7% in iCKO mice and 40.8 ± 9.3% in control mice), concomitant with increased expressions of fibrosis-related gene transcripts, including matrix metalloproteinase 9, procollagen 1, and procollagen 3. Echocardiography clarified that cardiac function was deteriorated in STAT3 iCKO mice (fractional shortening: 20.6 ± 4.1% in iCKO mice and 29.1 ± 6.0% in control mice). Dihydroethidium fluorescence analysis revealed that superoxide production was increased in STAT3 iCKO mice. Moreover, immunohistochemical analyses revealed that capillary density was decreased in STAT3 iCKO mice. Finally, STAT3 deletion in subacute MI evoked severe cardiac hypertrophy in the border zone. In conclusion, the intrinsic activity of STAT3 in the myocardium confers the resistance to cardiac remodeling in subacute MI.

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.

S6K inhibition renders cardiac protection against myocardial infarction through PDK1 phosphorylation of Akt

2011 ◽  
Vol 441 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Ruomin Di ◽  
Xiangqi Wu ◽  
Zai Chang ◽  
Xia Zhao ◽  
Qiuting Feng ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Weight Ratio ◽  
Left Ventricular ◽  
Cardiac Remodelling ◽  
Heart Weight ◽  
S6 Kinase ◽  
Beneficial Effects ◽  
Therapeutic Value ◽  
Specific Deletion

In the present study, we observed a rapid and robust activation of the ribosomal protein S6K (S6 kinase) provoked by MI (myocardial infarction) in mice. As activation of S6K promotes cell growth, we hypothesized that increased S6K activity contributes to pathological cardiac remodelling after MI and that suppression of S6K activation may prevent aberrant cardiac remodelling and improve cardiac function. In mice, administration of rapamycin effectively suppressed S6K activation in the heart and significantly improved cardiac function after MI. The heart weight/body weight ratio and fibrotic area were substantially reduced in rapamycin-treated mice. In rapamycin-treated mice, decreased cardiomyocyte remodelling and cell apoptosis were observed compared with vehicle-treated controls. Consistently, inhibition of S6K with PF-4708671 displayed similar protection against MI as rapamycin. Mechanistically, we observed significantly enhanced Thr308 phosphorylation and activation of Akt in rapamycin- and PF-4708671-treated hearts. Cardiomyocyte-specific deletion of PDK1 (phosphoinositide-dependent kinase 1) and Akt1/3 abolished cardioprotection after MI in the presence of rapamycin administration. These results demonstrate that S6K inhibition rendered beneficial effects on left ventricular function and alleviated adverse remodelling following MI in mice by enhancing Akt signalling, suggesting the therapeutic value of both rapamycin and PF-4708671 in treating patients following an MI.

Angiogenesis after acute myocardial infarction

2020 ◽  
Author(s):  
Xuekun Wu ◽  
Marc R Reboll ◽  
Mortimer Korf-Klingebiel ◽  
Kai C Wollert
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Tissue Repair ◽  
Left Ventricular ◽  
Lineage Tracing ◽  
Border Zone ◽  
Angiogenic Response ◽  
Mechanistic Understanding ◽  
Infarct Border Zone ◽  
Infarct Border

Abstract Acute myocardial infarction (MI) inflicts massive injury to the coronary microcirculation leading to vascular disintegration and capillary rarefication in the infarct region. Tissue repair after MI involves a robust angiogenic response that commences in the infarct border zone and extends into the necrotic infarct core. Technological advances in several areas have provided novel mechanistic understanding of postinfarction angiogenesis and how it may be targeted to improve heart function after MI. Cell lineage tracing studies indicate that new capillary structures arise by sprouting angiogenesis from pre-existing endothelial cells (ECs) in the infarct border zone with no meaningful contribution from non-EC sources. Single-cell RNA sequencing shows that ECs in infarcted hearts may be grouped into clusters with distinct gene expression signatures, likely reflecting functionally distinct cell populations. EC-specific multicolour lineage tracing reveals that EC subsets clonally expand after MI. Expanding EC clones may arise from tissue-resident ECs with stem cell characteristics that have been identified in multiple organs including the heart. Tissue repair after MI involves interactions among multiple cell types which occur, to a large extent, through secreted proteins and their cognate receptors. While we are only beginning to understand the full complexity of this intercellular communication, macrophage and fibroblast populations have emerged as major drivers of the angiogenic response after MI. Animal data support the view that the endogenous angiogenic response after MI can be boosted to reduce scarring and adverse left ventricular remodelling. The improved mechanistic understanding of infarct angiogenesis therefore creates multiple therapeutic opportunities. During preclinical development, all proangiogenic strategies should be tested in animal models that replicate both cardiovascular risk factor(s) and the pharmacotherapy typically prescribed to patients with acute MI. Considering that the majority of patients nowadays do well after MI, clinical translation will require careful selection of patients in need of proangiogenic therapies.

Direct Injection of Allogeneic Multipotent Adult Progenitor Cells Improves Cardiac Function after Myocardial Infarct.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2206-2206
Author(s):  
Wouter van’t Hof ◽  
Niladri Mal ◽  
Ming Zhang ◽  
Farhad Forudi ◽  
Robert Deans ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cardiac Function ◽  
Progenitor Cells ◽  
Intravenous Infusion ◽  
Direct Injection ◽  
Border Zone ◽  
Sprague Dawley ◽  
Multipotent Adult Progenitor Cells ◽  
Infarct Border Zone ◽  
Infarct Border

Abstract Multipotent adult progenitor cells (MAPC) are an early stem cell population identified in the bone marrow of adults. They have been shown to be capable of differentiating into cell populations derived from all 3 germ layers. We hypothesized that delivery of MAPC in the peri-infarct period could lead to improved cardiac function. MAPC were isolated from the bone marrow of Sprague-Dawley rats and stably labeled by using a lentiviral construct encoding green fluorescent protein (GFP). In-vitro differentiation assays confirmed that the GFP-tagged MAPCs had retained the potential for tri-lineage differentiation. Myocardial infarction was induced in Lewis rats by direct LAD ligation. Lewis rats received Sprague-Dawley MAPC either immediately after LAD ligation by directly injecting into the infarct border zone (5 injections of 400,000 cells per injection) or 24 h after MI by intravenous infusion (2 million cells). Immunohistochemistry was performed to identify MAPC (GFP positive cells) within the infarct zone 2 weeks after MI. We identified MAPC in the infarct border zone of all animals that received direct injection of MAPC, 2 weeks after MI, but did not identify any MAPC following intravenous infusion. Echocardiography was performed to determine if the delivery of MAPC to the myocardium at the time of MI led to improvement in cardiac function. At 2 weeks post-MI, we observed a significant increase in shortening fraction in those animals that received direct injection of MAPC compared to control (13.9 ± 2.2% (n=4) vs. 24.0 ± 6.6% (n=7), p=0.018). These data demonstrate that MAPC delivery to acutely infracted myocardium may offer significant benefit. These data further suggest that MAPC are capable of surviving in the myocardial tissue even when used in an allogeneic strategy without inducing a significant increase in inflammation or rejection.

scholarly journals STAT4 silencing underlies a novel inhibitory role of microRNA-141-3p in inflammation response of mice with experimental autoimmune myocarditis

2019 ◽  
Vol 317 (3) ◽  
pp. H531-H540 ◽  
Author(s):  
Aiqun Pan ◽  
Yuying Tan ◽  
Zhihao Wang ◽  
Guoliang Xu
Keyword(s):  
Body Weight ◽  
Cardiac Function ◽  
Weight Ratio ◽  
Heart Weight ◽  
Inflammatory Factor ◽  
Body Weight Ratio ◽  
Autoimmune Myocarditis ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

As an inflammatory disease afflicting the heart muscle, autoimmune myocarditis (AM) represents one of the foremost causes of heart failure. Accumulating evidence has implicated microRNAs (miRNAs) in the process of inflammation and autoimmunity. Hence, the current study aimed to investigate the mechanism by which miR-141-3p influences experimental AM (EAM). An EAM mouse model was established using 6-wk old male BALB/c mice, after which the expression of miR-141-3p and STAT4 was measured. Gain-of-function and loss-of-function investigations were performed to identify the functional role of miR-141-3p and STAT4 in EAM. Heart weight-to-body weight ratio, cardiac function, and degree of inflammation, as well as the levels of inflammation factors (IFN-γ, TNF-α, IL-2, IL-6, and IL-17) in the serum were detected. STAT4 was subsequently verified to be upregulated, and miR-141-3p was downregulated in the EAM mice. Furthermore, the overexpression of miR-141-3p or silencing of STAT4 was observed to reduce the heart weight-to-body weight ratio of EAM mice and improve cardiac function, while alleviating the degree of inflammatory cell infiltration in the myocardial tissue. Meanwhile, the overexpression of miR-141-3p was identified to diminish serum inflammatory factor levels by downregulating STAT4. Additionally, miR-141-3p could bind to STAT4 to downregulate its expression, ultimately mitigating inflammation and inducing an anti-inflammatory effect in EAM mice. Taken together, upregulation of miR-141-3p alleviates the inflammatory response in EAM mice by inhibiting STAT4, providing a promising intervention target for the molecular treatment of AM. NEW & NOTEWORTHY miR-141-3p is poorly expressed, and STAT4 is upregulated in experimental autoimmune myocarditis (EAM) mice. Overexpressing miR-141-3p inhibits EAM. miR-141-3p binds to and suppresses STAT4 expression. miR-141-3p overexpression inhibits inflammatory factors by downregulating STAT4. This study provides new insights into the treatment of autoimmune myocarditis.

scholarly journals A Characterization and Targeting of the Infarct Border Zone in a Swine Model of Myocardial Infarction

2012 ◽  
Vol 5 (5) ◽  
pp. 416-421 ◽  
Author(s):  
Jason M. Duran ◽  
Sharven Taghavi ◽  
Remus M. Berretta ◽  
Catherine A. Makarewich ◽  
Thomas Sharp III ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Border Zone ◽  
Swine Model ◽  
Infarct Border Zone ◽  
Infarct Border

scholarly journals Cardiomyocytes Cellular Phenotypes After Myocardial Infarction

2021 ◽  
Vol 8 ◽  
Author(s):  
Alessandra Maria Lodrini ◽  
Marie-José Goumans
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Contractility ◽  
Border Zone ◽  
Cell Level ◽  
Cellular Processes ◽  
Infarcted Heart ◽  
Ischemic Episode ◽  
Cellular Phenotypes ◽  
Infarct Border Zone ◽  
Infarct Border

Despite the increasing success of interventional coronary reperfusion strategies, mortality related to acute myocardial infarction (MI) is still substantial. MI is defined as sudden death of myocardial tissue caused by an ischemic episode. Ischaemia leads to adverse remodelling in the affected myocardium, inducing metabolic and ionic perturbations at a single cell level, ultimately leading to cell death. The adult mammalian heart has limited regenerative capacity to replace lost cells. Identifying and enhancing physiological cardioprotective processes may be a promising therapy for patients with MI. Studies report an increasing amount of evidence stating the intricacy of the pathophysiology of the infarcted heart. Besides apoptosis, other cellular phenotypes have emerged as key players in the ischemic myocardium, in particular senescence, inflammation, and dedifferentiation. Furthermore, some cardiomyocytes in the infarct border zone uncouple from the surviving myocardium and dedifferentiate, while other cells become senescent in response to injury and start to produce a pro-inflammatory secretome. Enhancing electric coupling between cardiomyocytes in the border zone, eliminating senescent cells with senolytic compounds, and upregulating cardioprotective cellular processes like autophagy, may increase the number of functional cardiomyocytes and therefore enhance cardiac contractility. This review describes the different cellular phenotypes and pathways implicated in injury, remodelling, and regeneration of the myocardium after MI. Moreover, we discuss implications of the complex pathophysiological attributes of the infarcted heart in designing new therapeutic strategies.

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