Inflammation in myocarditis induces cardiac injury and triggers disease progression to heart failure. NLRP3 inflammasome activation is a newly identified amplifying step in the pathogenesis of ...myocarditis. We previously have demonstrated that mesenchymal stromal cells (MSC) are cardioprotective in Coxsackievirus B3 (CVB3)-induced myocarditis. In this study, MSC markedly inhibited left ventricular (LV) NOD2, NLRP3, ASC, caspase-1, IL-1β, and IL-18 mRNA expression in CVB3-infected mice. ASC protein expression, essential for NLRP3 inflammasome assembly, increased upon CVB3 infection and was abrogated in MSC-treated mice. Concomitantly, CVB3 infection in vitro induced NOD2 expression, NLRP3 inflammasome activation and IL-1β secretion in HL-1 cells, which was abolished after MSC supplementation. The inhibitory effect of MSC on NLRP3 inflammasome activity in HL-1 cells was partly mediated via secretion of the anti-oxidative protein stanniocalcin-1. Furthermore, MSC application in CVB3-infected mice reduced the percentage of NOD2-, ASC-, p10- and/or IL-1β-positive splenic macrophages, natural killer cells, and dendritic cells. The suppressive effect of MSC on inflammasome activation was associated with normalized expression of prominent regulators of myocardial contractility and fibrosis to levels comparable to control mice. In conclusion, MSC treatment in myocarditis could be a promising strategy limiting the adverse consequences of cardiac and systemic NLRP3 inflammasome activation.
Mesenchymal stromal cell (MSC) application in Coxsackievirus B3 (CVB3)‐induced myocarditis reduces myocardial inflammation and fibrosis, exerts prominent extra‐cardiac immunomodulation, and improves ...heart function. Although the abovementioned findings demonstrate the benefit of MSC application, the mechanism of the MSC immunomodulatory effects leading to a final cardioprotective outcome in viral myocarditis remains poorly understood. Monocytes are known to be a trigger of myocardial tissue inflammation. The present study aims at investigating the direct effect of MSC on the mobilization and trafficking of monocytes to the heart in CVB3‐induced myocarditis. One day post CVB3 infection, C57BL/6 mice were intravenously injected with 1 x 106 MSC and sacrificed 6 days later for molecular biology and flow cytometry analysis. MSC application reduced the severity of myocarditis, and heart and blood pro‐inflammatory Ly6Chigh and Ly6Cmiddle monocytes, while those were retained in the spleen. Anti‐inflammatory Ly6Clow monocytes increased in the blood, heart, and spleen of MSC‐treated CVB3 mice. CVB3 infection induced splenic myelopoiesis, while MSC application slightly diminished the spleen myelopoietic activity in CVB3 mice. Left ventricular (LV) mRNA expression of the chemokines monocyte chemotactic protein‐1 (MCP)−1, MCP‐3, CCL5, the adhesion molecules intercellular adhesion molecule‐1, vascular cell adhesion molecule‐1, the pro‐inflammatory cytokines interleukin‐6, interleukin‐12, tumor necrosis factor‐α, the pro‐fibrotic transforming growth factorβ1, and circulating MCP‐1 and MCP‐3 levels decreased in CVB3 MSC mice, while LV stromal cell‐derived factor‐1α RNA expression and systemic levels of fractalkine were increased in CVB3 MSC mice. MSC application in CVB3‐induced myocarditis modulates monocytes trafficking to the heart and could be a promising strategy for the resolution of cardiac inflammation and prevention of the disease progression. Stem Cells Translational Medicine 2017;6:1249–1261
Allograft vasculopathy is the leading cause of death in patients with heart transplantation. Accelerated endothelial regeneration mediated by enhanced endothelial progenitor cell (EPC) incorporation ...may attenuate the development of allograft vasculopathy. We investigated the hypothesis that modulation of EPC biology and attenuation of allograft vasculopathy by increased high-density lipoprotein cholesterol after human apo A-I (AdA-I) transfer requires scavenger receptor (SR)–BI expression in bone marrow–derived EPCs. After AdA-I transfer, the number of circulating EPCs increased 2.0-fold (P < .001) at different time points in C57BL/6 mice transplanted with SR-BI+/+ bone marrow but remained unaltered in mice with SR-BI−/− bone marrow. The effect of high-density lipoprotein on EPC migration in vitro requires signaling via SR-BI and extracellular signal-regulated kinases and is dependent on increased nitric oxide (NO) production in EPCs. Human apo A-I transfer 2 weeks before paratopic artery transplantation reduced intimal area at day 21 3.7-fold (P < .001) in mice with SR-BI+/+ bone marrow but had no effect in mice with SR-BI−/− bone marrow. AdA-I transfer potently stimulated EPC incorporation and accelerated endothelial regeneration in chimeric SR-BI+/+ mice but not in chimeric SR-BI−/− mice. In conclusion, human apo A-I transfer accelerates endothelial regeneration mediated via SR-BI expressing bone marrow–derived EPCs, thereby preventing allograft vasculopathy.
Nerve growth factor (NGF) promotes angiogenesis and cardiomyocyte survival, which are both desirable for postinfarction myocardial healing. Nonetheless, the NGF potential for cardiac repair has never ...been investigated.
To define expression and localization of NGF and its high-affinity receptor TrkA (tropomyosin-related receptor A) in the human infarcted heart and to investigate the cardiac roles of both endogenous and engineered NGF using a mouse model of myocardial infarction (MI).
Immunostaining for NGF and TrkA was performed on heart samples from humans deceased of MI or unrelated pathologies. To study the post-MI functions of endogenous NGF, a NGF-neutralizing antibody (Ab-NGF) or nonimmune IgG (control) was given to MI mice. To investigate the NGF therapeutic potential, human NGF gene or control (empty vector) was delivered to the murine periinfarct myocardium. Results indicate that NGF is present in the infarcted human heart. Both cardiomyocytes and endothelial cells (ECs) possess TrkA, which suggests NGF cardiovascular actions in humans. In MI mice, Ab-NGF abrogated native reparative angiogenesis, increased EC and cardiomyocyte apoptosis and worsened cardiac function. Conversely, NGF gene transfer ameliorated EC and cardiomyocyte survival, promoted neovascularization and improved myocardial blood flow and cardiac function. The prosurvival/proangiogenic Akt/Foxo pathway mediated the therapeutic benefits of NGF transfer. Moreover, NGF overexpression increased stem cell factor (the c-kit receptor ligand) expression, which translated in higher myocardial abundance of c-kit(pos) progenitor cells in NGF-engineered hearts.
NGF elicits pleiotropic beneficial actions in the post-MI heart. NGF should be considered as a candidate for therapeutic cardiac regeneration.
Fibroblasts, which are traditionally recognized as a quiescent cell responsible for extracellular matrix production, are more and more appreciated as an active key player of the immune system. This ...review describes how fibroblasts and immune cells reciprocally influence the pathogenesis of fibrosis. An overview is given how fibroblasts are triggered by components of the innate and adaptive immunity on the one hand and how fibroblasts modulate immune cell behaviour via conditioning the cellular and cytokine microenvironment on the other hand. Finally, latest insights into the role of cardiac fibroblasts in the orchestration of inflammatory cell infiltration in the heart, and their impact on heart failure, are outlined.
Epidemiological studies support a strong association between high-density lipoprotein (HDL) cholesterol levels and heart failure incidence. Experimental evidence from different angles supports the ...view that low HDL is unlikely an innocent bystander in the development of heart failure. HDL exerts direct cardioprotective effects, which are mediated via its interactions with the myocardium and more specifically with cardiomyocytes. HDL may improve cardiac function in several ways. Firstly, HDL may protect the heart against ischaemia/reperfusion injury resulting in a reduction of infarct size and thus in myocardial salvage. Secondly, HDL can improve cardiac function in the absence of ischaemic heart disease as illustrated by beneficial effects conferred by these lipoproteins in diabetic cardiomyopathy. Thirdly, HDL may improve cardiac function by reducing infarct expansion and by attenuating ventricular remodelling post-myocardial infarction. These different mechanisms are substantiated by in vitro, ex vivo, and in vivo intervention studies that applied treatment with native HDL, treatment with reconstituted HDL, or human apo A-I gene transfer. The effect of human apo A-I gene transfer on infarct expansion and ventricular remodelling post-myocardial infarction illustrates the beneficial effects of HDL on tissue repair. The role of HDL in tissue repair is further underpinned by the potent effects of these lipoproteins on endothelial progenitor cell number, function, and incorporation, which may in particular be relevant under conditions of high endothelial cell turnover. Furthermore, topical HDL therapy enhances cutaneous wound healing in different models. In conclusion, the development of HDL-targeted interventions in these strategically chosen therapeutic areas is supported by a strong clinical rationale and significant preclinical data.
Graphical Abstract
Epicardial adipose tissue (EAT)-related heart failure with preserved ejection fraction (HFpEF). Obesity and type 2 diabetes mellitus (T2DM) are common triggers of HFpEF, frequently ...associated with EAT expansion. EAT plays metabolic and mechanical roles in HFpEF development
via
para/vasocrine factors and pericardial restrain, respectively. Life-style modifications including healthy diet and regular exercise can quash the EAT expansion. Statins, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and fat-modulating antidiabetics including metformin, sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 (GLP-1) agonists can target EAT. FFA, free fatty acids; AGEs, advanced glycation end-products; NO, nitric oxide; ROS, reactive oxygen species; Ang-II, angiotensin II; TGF-β, Transforming growth factor beta; MCP-1, monocyte chemoattractant protein 1; IL-6, interleukin 6; TNF-α, tumor necrosis factor alpha. Figure created
via
Servier Medical Art and BioRender tools.
Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome with diverse etiologies and pathophysiological factors. Obesity and type 2 diabetes mellitus (T2DM), conditions that coexist frequently, induce a cluster of metabolic and non-metabolic signaling derangements which are in favor to induce inflammation, fibrosis, myocyte stiffness, all hallmarks of HFpEF. In contrast to other HFpEF risk factors, obesity and T2DM are often associated with the generation of enlarged epicardial adipose tissue (EAT). EAT acts as an endocrine tissue that may exacerbate myocardial inflammation and fibrosis
via
various paracrine and vasocrine signals. In addition, an abnormally large EAT poses mechanical stress on the heart
via
pericardial restrain. HFpEF patients with enlarged EAT may belong to a unique phenotype that can benefit from specific EAT-targeted interventions, including life-style modifications and pharmacologically
via
statins and fat modifying anti-diabetics drugs; like metformin, sodium-glucose cotransporter 2 inhibitors, or glucagon-like peptide-1 receptor agonists, respectively.
The hallmarks of diabetic cardiomyopathy are cardiac oxidative stress, intramyocardial inflammation, cardiac fibrosis, and cardiac apoptosis. Given the antioxidative, antiinflammatory, and ...antiapoptotic potential of high-density lipoprotein (HDL), we evaluated the hypothesis that increased HDL via gene transfer (GT) with human apolipoprotein (apo) A-I, the principal apolipoprotein of HDL, may reduce the development of diabetic cardiomyopathy.
Intravenous GT with 3x10(12) particles/kg of the E1E3E4-deleted vector Ad.hapoA-I, expressing human apoA-I, or Ad.Null, containing no expression cassette, was performed 5 days after streptozotocin (STZ) injection. Six weeks after apoA-I GT, HDL cholesterol levels were increased by 1.6-fold (P<0.001) compared with diabetic controls injected with the Ad.Null vector (STZ-Ad.Null). ApoA-I GT and HDL improved LV contractility in vivo and cardiomyocyte contractility ex vivo, respectively. Moreover, apoA-I GT was associated with decreased cardiac oxidative stress and reduced intramyocardial inflammation. In addition, compared with STZ-Ad.Null rats, cardiac fibrosis and glycogen accumulation were reduced by 1.7-fold and 3.1-fold, respectively (P<0.05). Caspase 3/7 activity was decreased 1.2-fold (P<0.05), and the ratio of Bcl-2 to Bax was upregulated 1.9-fold (P<0.005), translating to 2.1-fold (P<0.05) reduced total number of cardiomyocytes with apoptotic characteristics and 3.0-fold (P<0.005) reduced damaged endothelial cells compared with STZ-Ad.Null rats. HDL supplementation ex vivo reduced hyperglycemia-induced cardiomyocyte apoptosis by 3.4-fold (P<0.005). The apoA-I GT-mediated protection was associated with a 1.6-, 1.6-, and 2.4-fold induction of diabetes-downregulated phospho to Akt, endothelial nitric oxide synthase, and glycogen synthase kinase ratio, respectively (P<0.005).
ApoA-I GT reduced the development of streptozotocin-induced diabetic cardiomyopathy.
This study evaluated whether intramyocardial injection of cardiac‐derived adherent proliferating cells (CardAPs) modulates cardiac fibrosis and hypertrophy in a mouse model of angiotensin II (Ang ...II)‐induced systolic heart failure and analyzed underlying mechanisms. Among other findings, results indicated that intramyocardial injection of CardAPs improved left ventricular (LV) function and reduced LV remodeling. These improvements were attributed to antifibrotic and antihypertrophic effects resulting from paracrine actions and immunomodulatory properties.
Acknowledgements
Cardiac‐derived adherent proliferating cells (CardAPs) are cells derived from human endomyocardial biopsy specimens; they share several properties with mesenchymal stromal cells. The aims of this study were to evaluate whether intramyocardial injection of CardAPs modulates cardiac fibrosis and hypertrophy in a mouse model of angiotensin II (Ang II)‐induced systolic heart failure and to analyze underlying mechanisms. Intramyocardial application of 200,000 CardAPs improved left ventricular function. This was paralleled by a decline in left ventricular remodeling, as indicated by a reduction in cardiac fibrosis and hypertrophy. CardAPs reduced the ratio of the left ventricle to body weight and cardiac myosin expression (heavy chain), and decreased the Ang II‐induced phosphorylation state of the cardiomyocyte hypertrophy mediators Akt, extracellular‐signal regulated kinase (ERK) 1, and ERK2. In accordance with the antifibrotic and antihypertrophic effects of CardAPs shown in vivo, CardAP supplementation with cardiac fibroblasts decreased the Ang II‐induced reactive oxygen species production, α‐SMA expression, fibroblast proliferation, and collagen production. Coculture of CardAPs with HL‐1 cardiomyocytes downregulated the Ang II‐induced expression of myosin in HL‐1. All antifibrotic and antihypertrophic features of CardAPs were mediated in a nitric oxide‐ and interleukin (IL)‐10‐dependent manner. Moreover, CardAPs induced a systemic immunomodulation, as indicated by a decrease in the activity of splenic mononuclear cells and an increase in splenic CD4CD25FoxP3, CD4‐IL‐10, and CD8‐IL‐10 T‐regulatory cells in Ang II mice. Concomitantly, splenocytes from Ang II CardAPs mice induced less collagen in fibroblasts compared with splenocytes from Ang II mice. We conclude that CardAPs improve Ang II‐induced cardiac remodeling involving antifibrotic and antihypertrophic effects via paracrine actions and immunomodulatory properties.
Despite effective pharmacological treatment with angiotensin II type I receptor antagonists or angiotensin II‐converting enzyme inhibitors, morbidity and mortality associated with heart failure are still substantial, prompting the search of novel therapeutic strategies. There is accumulating evidence supporting the use of cell therapy for cardiac repair. This study demonstrates that cells derived from human endomyocardial biopsies, cardiac‐derived adherent proliferating cells (CardAPs), have the potential to reduce angiotensin II‐induced cardiac remodeling and improve left ventricular function in angiotensin II mice. The mechanism involves antifibrotic and antihypertrophic effects via paracrine actions and immunomodulatory properties. These findings support the potential of CardAPs for the treatment of heart failure.
PDF
