scholarly journals Quantitative and qualitative composition of the innate immune response are equally important in wound healing after myocardial infarction

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J Wrobel ◽  
J Rettkowski ◽  
H Seung ◽  
C Wadle ◽  
P Stachon ◽  
...  

Abstract Background Emergency hematopoiesis (EH) serves as the foundation of monocyte-derived and macrophage (Mφ) driven efferocytosis and ventricular remodeling after myocardial infarction (MI). Excessive myelopoiesis, however, can stipulate maladaptive wound healing and its therapeutic reduction may be a novel approach to preserve cardiac function. All-trans retinoic acid (ATRA) is a pleiotropic modulator of EH and innate immunity shielding hematopoietic stem cells from activation and driving survival and differentiation of myeloid cells. Purpose This study aimed to investigate this intriguing interplay of ATRA in wound healing after MI. Methods MI was induced by permanent coronary ligation in C57BL/6 mice and treated with daily injections of either ATRA (30mg/kg) or DMSO (vehicle) up to five days, starting 24h after ligation. Flow cytometry (FACS) was used for cell cycle analysis and immunophenotyping of leukocytes in bone marrow (BM), blood and heart. Immunohistochemistry (IH), masson trichrome (MT) staining and echocardiography evaluated inflammatory-fibrotic and functional development. Cytokine expression was analyzed by qPCR in bulk infarct and isolated, polarized Mφ-populations of BM-derived and cardiac resident origin. Results On day 2 after MI, EH was significantly reduced in ATRA-treated mice as compared to vehicle controls by means of cell cycle activity (n=6–13 per group; p<0,01) and myeloid cells in BM, blood and infarct tissue (n=5–13; p<0,05). Consequently, mRNA-expression of key inflammatory cytokines, IL-1β and TNFα, was diminished in the infarct tissue in this early phase (n=5–12; p<0,05). These changes, however, failed to preserve cardiac function and ventricular remodeling, 21 days after MI (n=10–11; not significant). By qPCR, non-canonical activation of recruited ATRA-primed monocyte-derived Mφ, was found to propagate a pro-inflammatory phenotype with higher expression of MMP2 and MMP9 in sorted cardiac Mφ (n=4–5; p<0,001). Furthermore, prominent IL-1β-expression in M2-polarized BM-derived Mφ indicated an impaired anti-inflammatory phenotype after ATRA treatment (n=4–6; p<0,05). Strikingly, these changes also occurred in remote myocardium where IH revealed a 2-fold increase of CD11b - positive myeloid cells accompanied by increased expression of TNFα and TGFβ (n=9; p<0,001). MT-staining, performed 21 days after MI, demonstrated an almost 3-fold increase in collagen deposition in remote myocardium of ATRA treated mice in contrast to vehicle controls (n=4–6; p<0,0001). Conclusion Despite a beneficial reduction of EH after MI, short-term treatment with ATRA induced profound and persisting changes in the cytokine expression of monocyte-derived Mφ, which significantly altered their function and thus prevented improvements in cardiac function. Our data provide evidence that quantitative and qualitative changes in innate immunity are equally important for cardiac remodeling after MI. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft

PLoS ONE ◽  
2012 ◽  
Vol 7 (12) ◽  
pp. e51991 ◽  
Author(s):  
Eva Mathieu ◽  
Guillaume Lamirault ◽  
Claire Toquet ◽  
Pierre Lhommet ◽  
Emilie Rederstorff ◽  
...  

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jonas Neuser ◽  
Daniela Fraccarollo ◽  
Jan P Tuckermann ◽  
Paolo Galuppo ◽  
Johann Bauersachs

Background: Glucocorticoid administration impairs ischemic wound healing by inhibiting inflammation and angiogenesis via a glucocorticoid receptor (GR)-mediated transcriptional response. However, there are also apparently contradictory reports claiming protective effects of glucorticoid administration after myocardial infarction (MI). We investigated the role of the GR in myeloid cells for infarct wound healing, using GR deficient mice (GRLysMCre). Methods and Results: MI was induced by permanent left coronary artery ligation in GRflox (wild-type [WT] controls) and GRLysMCre mice. The 7-day mortality was significantly lower in WT compared with GRLysMCre mice. At 7 days post MI, GRLysMCre mice exhibited significantly enhanced thinning and dilatation of the infarcted wall, LV chamber enlargement and functional deterioration. This was associated with altered granulation tissue formation and impaired neoangiogenesis at the site of ischemic injury. Multicolor flow cytometric analysis and immunohistochemical studies revealed at the 2nd day post infarction less infiltrating mononuclear cells [CD11bhigh and (CD49b, NK1.1, B220, CD90, Ly6G)low] in the healing myocardium of GRLysMCre mice. Mononuclear cells were identified as monocytes (F4/80, I-Ab, CD11c)low and as macrophages/dendritic cells (F4/80, I-Ab, CD11c)high. Monocytes lacking GR, isolated from peripheral blood and spleen by magnetic-activated cell sorting 1 day after MI, displayed reduced migration capacity and increased superoxide anion production in mitochondria, which was detected by HPLC-electrochemical analysis of Mito-2-hydroxy-E+. Moreover, at day 2 and 3 we found enhanced cellular and mitochondrial oxidative stress in the healing myocardium of GRLysMCre mice. Conclusions: Myeloid-specific deletion of the GR increasing mitochondrial oxidative stress alters wound healing and promotes infarct expansion. Our results suggest that the GR in myeloid cells play a crucial role during cardiac repair after myocardial infarction.


2021 ◽  
Author(s):  
Hongyao Hu ◽  
Wei Li ◽  
Yanzhao Wei ◽  
Hui Zhao ◽  
Zhenzhong Wu ◽  
...  

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.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Yasmine Zouggari ◽  
Hafid Ait-Oufella ◽  
Philippe Bonnin ◽  
José Vilar ◽  
Coralie Guerin ◽  
...  

Leukocyte infiltration in ischemic areas is a hallmark of myocardial infarction, and persistent infiltration of innate immune cells, such as neutrophils and Ly6Chi monocytes, has been shown to promote adverse cardiac tissue remodeling. However, little is known regarding the role of mature B lymphocytes, which play a crucial role in the activation of the inflammatory response in several immune-mediated diseases. Here, we hypothesized that B lymphocytes might modulate the inflammatory response and affect the immune-dependent adverse cardiac remodeling. In a mouse model of myocardial infarction, cardiac B lymphocytes levels peaked at day 5 after the onset of infarction. Of interest, treatment with a CD20-specific monoclonal antibody decreased circulating and infiltrating B cell numbers (p=0.0008 and p=0.0002 vs control), reduced infarct size and post-ischemic immunoinflammatory response, and improved cardiac function (p=0.02 vs control) assessed by echocardiography. Intriguingly, B cell depletion was associated with an impairment of Ly6Chi monocytes mobilization from bone marrow (p=0.02 vs control), leading to reduced levels of circulating and infiltrating cardiac monocytes. The acute infarction led to transient increase of both MCP-1 and MCP-3 levels. Interestingly, B cell depletion was associated with a significant and selective reduction of MCP-3 (p=0.03 vs control) but did not alter MCP-1 levels (p=0.11). Cultured activated B cells released MCP-3 and treatment with a neutralizing MCP-3 antibody abrogated B lymphocytes-induced migration of cultured monocytes. Finally, transfer of B cell-depleted splenocytes into Rag1 -/- mice improved cardiac function after myocardial infarction compared to the transfer of non-depleted splenocytes (p=0.005). This effect was abrogated after re-supplementation with B lymphocytes isolated from wild-type mice (p=0.0007) but not from MCP-3-deficient animals (p=0.7008). In conclusion, we show that following acute myocardial infarction, B lymphocytes, trigger an MCP-3-dependent mobilization of Ly6Chi monocytes from the bone marrow to the blood, leading to their recruitment into the injured myocardium and to exacerbation of tissue inflammation, thereby promoting adverse cardiac remodeling.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
James Tsoporis ◽  
Shehla Izhar ◽  
Jean-Francois Desjardins ◽  
Gerald Proteau ◽  
Gustavo Yannarelli ◽  
...  

The beneficial effects originally attributed to the ability of bone-marrow derived mesenchymal stromal cells (BM-MSCs) to differentiate into cardiomyocytes have been questioned due to the transient presence of donor cells at injury site following myocardial infarction (MI) suggesting that the MSC-induced improvement in hemodynamic function may be attributable to paracrine effects. We showed that S100A6, a 20 kDa EF-hand calcium-binding dimer, is upregulated and secreted following MI and forced expression post-MI was beneficial to the preservation of cardiac function. The aim of this study was to determine whether the beneficial effects of infused BM-MSCs may be related to the autocrine secretion of S100A6. Balb/c murine cultured green fluorescence protein (GFP)-marked BM-MSCs express S100A6 at baseline and in response to hypoxia (5%C02/95% N2) for 1 hr increase S100A6 mRNA and protein (2-3 fold, and release S100A6 (1 nM) in the culture media, responses inhibited in BM-MSCs transfected with S100A6 siRNA. Treatment of neonatal Balb/c cardiac myocytes with human recombinant S100A6 (1nM) for 1-24 hrs attenuated baseline apoptosis (30 per cent decrease in BAX/BCL2 ratio), induced cyclin-dependent kinase 1(CDK1) mRNA 1.5 fold, miR199a 2 fold and myocyte proliferation 2.5 fold, the latter inhibited by anti-miR 199a. In 12 week old Balb/c mice, saline or GFP-marked BM-MSCs transfected with either a scrambled or S100A6 siRNA were infused intravenously 3-4 hrs post coronary artery ligation. After 3-4 days the GFP-marked cells were confined to ischemic areas and represented approximately 10% of total cellularity and co-expressed collagen type IV and myosin heavy chain, characteristic of MSCs and cardiomyocytes, respectively, and were CD45(-). Despite the absence of donor cells in the infarcted myocardium 21 days after infusion, mice that have received MSCs alone compared to MSCs transfected with an S100A6 siRNA or saline alone showed a 6-fold increase in S100A6 mRNA and protein, 3-fold increase in miR199a in peri-infarcted myocardium, attenuated myocyte hypertrophy, decreased fibrosis and apoptosis, and preservation of cardiac function. In conclusion, the secretion of S100A6 by infused BM-MSCs may contribute in limiting adverse LV remodeling post-MI.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Jingrui Chen ◽  
Jing wei ◽  
John Orgah ◽  
Yan Zhu ◽  
Jingyu Ni ◽  
...  

Background. Danhong injection (DHI) has been mainly used for the treatment of myocardial infarction, atherosclerosis, and coronary heart disease in clinical practice. Our previous studies have shown that DHI improves ventricular remodeling and preserves cardiac function in rats with myocardial infarction (MI). In this study, we focused on the potential mechanism of DHI in protecting cardiac function in MI rats. Methods. Sprague-Dawley rats were subjected to ligation of the left anterior descending coronary artery (LAD) to prepare a myocardial infarction (MI) model. After 14 day DHI intervention, cardiac function was measured by echocardiography and myocardial fibrosis was assessed by Masson staining. Differentiated miRNAs were screened using rat immunopathology miScript miRNA PCR arrays, and their results were verified by RT-PCR, immunofluorescence, and immunoblotting. Results. DHI treatment significantly reduced infarct size and improved cardiac function and hemodynamics in MI rats by echocardiography and morphology. miRNA PCR array results showed that DHI reversed 25 miRNAs known to be associated with inflammation and apoptosis. Moreover, the expression of inflammatory factors TNF-α, IL-1β, and IL-6 was significantly reduced in the treated DHI group. Mechanistically, DHI downregulated the inflammatory transcription factor NF-κB (as reflected by inhibition of NF-κB p65 nuclear translocation and phosphorylation of the IκBα). Conclusions. DHI is effective in mitigating inflammation associated with MI by preventing NF-κB nuclear translocation and regulating miRNAs, thereby improving cardiac function in myocardial infarction rats.


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