Endothelial Forkhead Box Transcription Factor P1 Regulates Pathological Cardiac Remodeling Through Transforming Growth Factor-β1-Endothelin-1 Signal Pathway

A detrimental role of endothelial S1PR2 in cardiac ischemia-reperfusion injury via modulating mitochondrial dysfunction, NLRP3 inflammasome activation, and pyroptosis

Sphingosine 1-phosphate (S1P), a bioactive lipid molecule, exerts multifaceted effects on cardiovascular functions via S1P receptors, but its effects on cardiac I/R injury are not fully understood. Plasma lipidomics analysis by mass spectrometry revealed that sphingosine lipids, including sphingosine 1-phosphate (S1P), were significantly down-regulated following cardiac I/R injury in mice. The reduced S1P levels were also observed in the plasma of coronary heart disease (CHD) patients after percutaneous coronary intervention (PCI) compared with those without PCI. We found that S1P exerted a cardioprotective effect via endothelial cell (EC)-S1PR1, whereas EC-S1PR2 displayed a detrimental effect on cardiac I/R. Our data showed that EC-specific S1pr2 loss-of-function significantly lessened inflammatory responses and diminished cardiac I/R injury, while EC-specific S1pr2 gain-of-function aggravated cardiac I/R injury. Mechanistically, EC-S1PR2 initiated excessive mitochondrial fission and elevated ROS production via RHO/ROCK1/DRP1 pathway, leading to NLRP3 inflammasome activation and subsequent cell pyroptosis, thereby exacerbating inflammation and I/R injuries. Furthermore, RGD-peptide magnetic nanoparticles packaging S1pr2-siRNA to specifically knockdown S1PR2 in endothelial cells significantly ameliorated cardiac I/R injury. Taken together, our investigations demonstrate that EC-S1PR2 induces excessive mitochondrial fission, which results in NLRP3 inflammasome activation and subsequently triggers cell pyroptosis, ultimately exacerbating inflammatory responses and aggravating heart injuries following I/R.

Nanomedicine: A great boon for cardiac regenerative medicine

Cardiovascular disease (CVD) represents a significant global health challenge, remaining the leading cause of illness and mortality worldwide. The adult heart's limited regenerative capacity poses a major obstacle in repairing extensive damage caused by conditions like myocardial infarction. In response to these challenges, nanomedicine has emerged as a promising field aimed at improving treatment outcomes through innovative drug delivery strategies. Nanocarriers, such as nanoparticles (NPs), offer a revolutionary approach by facilitating targeted delivery of therapeutic agents directly to the heart. This precise delivery system holds immense potential for treating various cardiac conditions by addressing underlying mechanisms such as inflammation, oxidative stress, cell death, extracellular matrix remodeling, prosurvival signaling, and angiogenic pathways associated with ischemia-reperfusion injury. In this review, we provide a concise summary of the fundamental mechanisms involved in cardiac remodeling and regeneration. We explore how nanoparticle-based drug delivery systems can effectively target the afore-mentioned mechanisms. Furthermore, we discuss clinical trials that have utilized nanoparticle-based drug delivery systems specifically designed for cardiac applications. These trials demonstrate the potential of nanomedicine in clinical settings, paving the way for future advancements in cardiac therapeutics through precise and efficient drug delivery. Overall, nanomedicine holds promise in revolutionizing the treatment landscape of cardiovascular diseases by offering targeted and effective therapeutic strategies that address the complex pathophysiology of cardiac injuries.

Demonstration of the Protective Effect of Vinpocetine in Diabetic Cardiomyopathy

Background: Diabetic cardiomyopathy (DCM) poses a significant risk for heart failure in individuals with diabetes, yet its underlying mechanisms remain incompletely understood. Elevated blood sugar levels initiate harmful processes, including apoptosis, collagen accumulation, and fibrosis in the heart. Vinpocetine, a derivative of Vinca minor L., has demonstrated diverse pharmacological effects, including vasodilation, anti-inflammatory properties, and enhanced cellular metabolism. This study aims to investigate Vinpocetine's protective and remodeling effects in diabetic cardiomyopathy by evaluating biochemical and histopathological parameters. Methods: Twenty-one adult male Wistar rats were induced with diabetes using streptozocin and divided into Diabetes and Diabetes + Vinpocetine groups. Histopathological analyses, TGF-β1 immunoexpression, and measurements of plasma markers (TGF-β, pro-BNP, Troponin T) were performed. Biochemical analyses included HIF-1 alpha and neuregulin-1β quantification and evaluation of lipid peroxidation. Results: Vinpocetine significantly reduced cardiac muscle thickness, TGF-β1 expression, and plasma in diabetic rats. HIF-1 alpha and neuregulin-1β levels increased with Vinpocetine treatment. Histopathological observations confirmed reduced fibrosis and structural abnormalities in Vinpocetine-treated hearts. Conclusions: This study provides comprehensive evidence supporting the protective effects of Vinpocetine against diabetic cardiomyopathy. Vinpocetine treatment improved cardiac morphology, immunohistochemistry, and modulation of biochemical markers, suggesting its potential as a therapeutic intervention to attenuate the negative impact of diabetes on heart function.

Caffeic acid mitigates myocardial fibrosis and improves heart function in post-myocardial infarction by inhibiting transforming growth factor-β receptor 1 signaling pathways

Myocardial fibrosis is a pathological, physiological change that results from alterations, such as inflammation and metabolic dysfunction, after myocardial infarction (MI). Excessive fibrosis can cause cardiac dysfunction, ventricular remodeling, and heart failure. Caffeic acid (CA), a natural polyphenolic acid in various foods, has cardioprotective effects. This study aimed to explore whether CA exerts a cardioprotective effect to inhibit myocardial fibrosis post-MI and elucidate the underlying mechanisms. Histological observations indicated that CA ameliorated ventricular remodeling induced by left anterior descending coronary artery ligation in MI mice and partially restored cardiac function. CA selectively targeted transforming growth factor-β receptor 1 (TGFBR1) and inhibited TGFBR1-Smad2/3 signaling, reducing collagen deposition in the infarcted area of MI mice hearts. Furthermore, cell counting (CCK-8) assay, 5-ethynyl-2'-deoxyuridine assay, and western blotting revealed that CA dose-dependently decreased the proliferation, collagen synthesis, and activation of the TGFBR1-Smad2/3 pathway in primary cardiac fibroblasts (CFs) stimulated by TGF-β1 in vitro. Notably, TGFBR1 overexpression in CFs partially counteracted the inhibitory effects of CA. These findings suggest that CA effectively mitigates myocardial fibrosis and enhances cardiac function following MI and that this effect may be associated with the direct targeting of TGFBR1 by CA.

Long-term prognostic value of big endothelin-1 and its combination with late gadolinium enhancement in patients with idiopathic restrictive cardiomyopathy

BACKGROUND AND AIMS

Idiopathic restrictive cardiomyopathy (RCM) has a low incidence. This study aimed to determine the prognostic value of big endothelin-1 (ET-1) in idiopathic RCM.

MATERIALS AND METHODS

We prospectively enrolled patients with idiopathic RCM from 2009 to 2017 and followed them up. The primary outcome was a composite of all-cause mortality and cardiac transplantation, and the secondary outcome was a composite of cardiac death and cardiac transplantation.

RESULTS

Ninety-one patients were divided into the high big ET-1 (>0.85 pmol/L, n = 56) and low big ET-1 (≤0.85 pmol/L, n = 35) groups, and 87 of them completed the follow-up. Big ET-1 concentrations (hazard ratio: 1.756, 95 % confidence interval [CI]: 1.117-2.760) and late gadolinium enhancement (LGE) (hazard ratio: 3.851, 95 % CI: 1.238-11.981) were independent risk factors for the primary outcome. Big ET-1 concentrations (C-statistic estimation: 0.764, 95 % CI: 0.657-0.871) and the combination of LGE and big ET-1 concentrations (C-statistic estimation: 0.870, 95 % CI: 0.769-0.970) could accurately predict the 5-year transplant-free survival rate, and 0.85 pmol/L was a suitable cutoff for big ET-1.

CONCLUSION

Big ET-1 and its combination with LGE may be useful to predict an adverse prognosis in patients with idiopathic RCM.

Fraxinellone alleviates colitis-related intestinal fibrosis by blocking the circuit between PD-1+ Th17 cells and fibroblasts

BACKGROUND

Excessive activation of colonic fibroblasts and differentiation of T helper 17 (Th17) cells are the key steps for intestinal fibrogenesis in the process of inflammatory bowel disease (IBD). Although both transforming growth factor-beta (TGF-β)/Mothers Against Decapentaplegic Homolog (SMAD) 3-induced fibroblasts activation and interleukin (IL)-6/signal transducer and activator of transcription (STAT) 3-induced Th17 differentiation have been well studied, the crosstalk between fibroblasts and Th17 cells in the process of intestinal fibrogenesis needs to be unveiled.

METHODS

In this study, the activation of colonic fibroblasts was induced with dextran sulfate sodium salt (DSS) and TGF-β in vivo and in vitro respectively. P-SMAD3 and its downstream targets were quantified using RT-PCR, western blot and immunofluorescence. The differentiation of programmed death 1 (PD-1) + Th17 and activation of fibroblasts were quantified by FACS. PD-1+ Th17 cells and fibroblasts were co-cultured and cytokines in the supernatant were tested by ELISA. The anti-fibrosis effects of different chemical compounds were validated in vitro and further confirmed in vivo.

RESULTS

The colonic fibroblasts were successfully activated by DSS and TGF-β in vivo and in vitro respectively, as activation markers of fibroblasts (p-SMAD3 and its downstream targets such as Acta2, Col1a1 and Ctgf) were significantly increased. The activated fibroblasts produced more IL-6 compared with their inactivated counterparts in vivo and in vitro. The proinflammatory cytokine IL-6 induced PD-1+ Th17 differentiation and TGF-β that in return promoted the activation of colonic fibroblasts. Fraxinellone inhibited TGF-β+ PD-1+ Th17 cells via deactivating STAT3.

CONCLUSIONS

The reciprocal stimulation constructed a circuit of PD-1+ Th17 cells and fibroblasts that accelerated the fibrosis process. Fraxinellone was selected as the potential inhibitor of the circuit of PD-1+ Th17 cells and fibroblasts in vivo and in vitro. Inhibiting the circuit of PD-1+ Th17 cells and fibroblasts could be a promising strategy to alleviate intestinal fibrosis.

Protective Effect of CD137 Deficiency Against Postinfarction Cardiac Fibrosis and Adverse Cardiac Remodeling by ERK1/2 Signaling Pathways

ABSTRACT

Myocardial fibrosis, a common complication of myocardial infarction (MI), is characterized by excessive collagen deposition and can result in impaired cardiac function. The specific role of CD137 in the development of post-MI myocardial fibrosis remains unclear. Thus, this study aimed to elucidate the effects of CD137 signaling using CD137 knockout mice and in vitro experiments. CD137 expression levels progressively increased in the heart after MI, particularly in myofibroblast, which play a key role in fibrosis. Remarkably, CD137 knockout mice exhibited improved cardiac function and reduced fibrosis compared with wild-type mice at day 28 post-MI. The use of Masson's trichrome and picrosirius red staining demonstrated a reduction in the infarct area and collagen volume fraction in CD137 knockout mice. Furthermore, the expression of alpha-smooth muscle actin and collagen I, key markers of fibrosis, was decreased in heart tissues lacking CD137. In vitro experiments supported these findings because CD137 depletion attenuated cardiac fibroblast differentiation, and migration, and collagen I synthesis. In addition, the administration of CD137L recombinant protein further promoted alpha-smooth muscle actin expression and collagen I synthesis, suggesting a profibrotic effect. Notably, the application of an inhibitor targeting the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway attenuated the profibrotic effects of CD137L. To conclude, this study provides evidence that CD137 plays a significant role in promoting myocardial fibrosis after MI. Inhibition of CD137 signaling pathways may hold therapeutic potential for mitigating pathological cardiac remodeling and improving post-MI cardiac function.

Umbilical cord mesenchymal stem cell-derived exosomes inhibits fibrosis in human endometrial stromal cells via miR-140-3p/FOXP1/Smad axis

Endometrial fibrosis is the histologic appearance of intrauterine adhesion (IUA). Emerging evidences demonstrated umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exo) could alleviate endometrial fibrosis. But the specific mechanism is not clear. In this study, we explored the effect of UCMSC-exo on endometrial fibrosis, and investigated the possible role of miR-140-3p/FOXP1/Smad axis in anti-fibrotic properties of UCMSC-exo. UCMSC-exo were isolated and identified. Transforming growth factor-β (TGF-β) was used to induce human endometrial stromal cell (HESC) fibrosis. Dual luciferase assay was performed to verify the relationship between miR-140-3p and FOXP1. The expressions of fibrotic markers, SIP1, and p-Smad2/p-Smad3 in HESCs stimulated with UCMSC-exo were detected by western blot. In addition, the effects of miR-140-3p mimic, miR-140-3p inhibitor and FOXP1 over-expression on endometrial fibrosis were assessed. The isolated UCMSC-exo had a typical cup-shaped morphology and could be internalized into HESCs. The expressions of fibrotic markers were significantly increased by TGF-β, which was reversed by UCMSC-exo. MiR-140-3p in UCMSC-exo ameliorated TGf-β-induced HESCs fibrosis. FOXP1 was identified as the direct target of miR-140-3p, which could inversely regulate miR-140-3p's function on HESCs fibrosis. Furthermore, we demonstrated that miR-140-3p in UCMSC-exo regulated Smad signal pathway to exert the anti-fibrotic effect in HESCs. The anti-fibrotic effect of UCMSC-derived exosomes against HESC fibrosis was at least partially achieved by miR-140-3p/FOXP1/Smad axis.

TRPM2 knockdown attenuates myocardial apoptosis and promotes autophagy in HFD/STZ-induced diabetic mice via regulating the MEK/ERK and mTORC1 signaling pathway

Diabetic cardiomyopathy (DCM) is a major complication of diabetes. Transient receptor potential melastatin 2 (TRPM2) activity increases in diabetic oxidative stress state, and it is involved in myocardial damage and repair. We explore the protective effect of TRPM2 knockdown on the progression of DCM. A type 2 diabetes animal model was established in C57BL/6N mice by long-term high-fat diet (HFD) feeding combined with a single injection of 100-mg/kg streptozotocin (STZ). Genetic knockdown of TRPM2 in heart was accomplished by the intravenous injection via the tail vein of adeno-associated virus type 9 carrying TRPM2 shRNA. Neonatal rat ventricular myocytes was exposed to 45 mM of high-glucose (HG) stimulation for 72 h in vitro to mimic the in vivo conditions. Western blot, real-time quantitative PCR (RT-qPCR), immunohistochemistry and fluorescence, electron, CCK-8, and flow cytometry were used to evaluate the phenotype of cardiac inflammation, fibrosis, apoptosis, and autophagy. Mice with HFD/STZ-induced diabetes exhibited systolic and diastolic dysfunction, as demonstrated by increased myocardial apoptosis and autophagy inhibition in the heart. Compared to control group, the protein expression of TRPM2, bax, cleaved caspase-3, and P62 was significantly elevated, and the protein expression of bcl-2 and LC3-II was significantly decreased in the myocardial tissues of the HFD/STZ-induced diabetes group. Knockdown of TRPM2 significantly reversed the HFD/STZ-induced myocardial apoptosis and autophagy inhibition. TRPM2 silencing attenuated HG-induced apoptosis and autophagy inhibition in primary cardiomyocytes via regulating the MEK/ERK mTORC1 signaling pathway. TRPM2 knockdown attenuates hyperglycemia-induced myocardial apoptosis and promotes autophagy in HFD/STZ-induced diabetic mice or HG-stimulated cardiomyocytes via regulating the MEK/ERK and mTORC1 signaling pathway.

Reprogramming endothelial cells to empower cancer immunotherapy

Cancer immunity is subject to spatiotemporal regulation by leukocyte interaction with the tumor microenvironment. Growing evidence suggests an emerging role for the vasculature in tumor immune evasion and immunotherapy resistance. Beyond the conventional functions of the tumor vasculature, such as providing oxygen and nutrients to support tumor progression, we propose multiplex mechanisms for vascular regulation of tumor immunity: The immunosuppressive vascular niche locoregionally educates circulation-derived immune cells by angiocrines, aberrant endothelial metabolism induces T cell exclusion and inactivation, and topologically and biochemically abnormal vascularity forms a pathophysiological barrier that hampers lymphocyte infiltration. We postulate that genetic and metabolic reprogramming of endothelial cells may rewire the immunosuppressive vascular microenvironment to overcome immunotherapy resistance, serving as a next-generation vascular targeting strategy for cancer treatment.

Transcription factors regulating vasculogenesis and angiogenesis

Transcription factors (TFs) play a crucial role in regulating the dynamic and precise patterns of gene expression required for the initial specification of endothelial cells (ECs), and during endothelial growth and differentiation. While sharing many core features, ECs can be highly heterogeneous. Differential gene expression between ECs is essential to pattern the hierarchical vascular network into arteries, veins and capillaries, to drive angiogenic growth of new vessels, and to direct specialization in response to local signals. Unlike many other cell types, ECs have no single master regulator, instead relying on differing combinations of a necessarily limited repertoire of TFs to achieve tight spatial and temporal activation and repression of gene expression. Here, we will discuss the cohort of TFs known to be involved in directing gene expression during different stages of mammalian vasculogenesis and angiogenesis, with a primary focus on development.

Epigenetic signatures in cardiac fibrosis: Focusing on noncoding RNA regulators as the gatekeepers of cardiac fibroblast identity

Cardiac fibroblasts play a pivotal role in cardiac fibrosis by transformation of fibroblasts into myofibroblasts, which synthesis and secrete a large number of extracellular matrix proteins. Ultimately, this will lead to cardiac wall stiffness and impaired cardiac performance. The epigenetic regulation and fate reprogramming of cardiac fibroblasts has been advanced considerably in recent decades. Non coding RNAs (microRNAs, lncRNAs, circRNAs) regulate the functions and behaviors of cardiac fibroblasts, including proliferation, migration, phenotypic transformation, inflammation, pyroptosis, apoptosis, autophagy, which can provide the basis for novel targeted therapeutic treatments that abrogate activation and inflammation of cardiac fibroblasts, induce different death pathways in cardiac fibroblasts, or make it sensitive to established pathogenic cells targeted cytotoxic agents and biotherapy. This review summarizes our current knowledge in this field of ncRNAs function in epigenetic regulation and fate determination of cardiac fibroblasts as well as the details of signaling pathways contribute to cardiac fibrosis. Moreover, we will comment on the emerging landscape of lncRNAs and circRNAs function in regulating signal transduction pathways, gene translation processes and post-translational regulation of gene expression in cardiac fibroblast. In the end, the prospect of cardiac fibroblasts targeted therapy for cardiac fibrosis based on ncRNAs is discussed.

MiR-522-3p Attenuates Cardiac Recovery by Targeting FOXP1 to Suppress Angiogenesis

Angiogenesis is crucial for blood supply reconstitution after myocardial infarction in patients with acute coronary syndrome (ACS). MicroRNAs are recognized as important epigenetic regulators of endothelial angiogenesis. The purpose of this study is to determine the roles of miR-522-3p in angiogenesis after myocardial infarction. The expression levels of miR-522-3p in rats' plasma and in the upper part of the ligation of the heart tissues at 28 days after myocardial infarction were significantly higher than those of the sham group. miR-522-3p mimics inhibited cell proliferations, migrations, and tube formations under hypoxic conditions in HUVECs (human umbilical vein endothelial cells), whereas miR-522-3p inhibitors did the opposite. Furthermore, studies have indicated that the inhibition of miR-522-3p by antagomir infusion promoted angiogenesis and accelerated the recovery of cardiac functions in rats with myocardial infarction.Data analysis and experimental results revealed that FOXP1 (Forkhead-box protein P1) was the target gene of miR-522-3p. Our study explored the mechanism of cardiac angiogenesis after myocardial infarction and provided a potential therapeutic approach for the treatment of ischemic heart disease in the future.

Fatty acid β-oxidation and mitochondrial fusion are involved in cardiac microvascular endothelial cell protection induced by glucagon receptor antagonism in diabetic mice

INTRODUCTION

The role of cardiac microvascular endothelial cells (CMECs) in diabetic cardiomyopathy is not fully understood. We aimed to investigate whether a glucagon receptor (GCGR) monoclonal antibody (mAb) ameliorated diabetic cardiomyopathy and clarify whether and how CMECs participated in the process.

RESEARCH DESIGN AND METHODS

The db/db mice were treated with GCGR mAb or immunoglobulin G (as control) for 4 weeks. Echocardiography was performed to evaluate cardiac function. Immunofluorescent staining was used to determine microvascular density. The proteomic signature in isolated primary CMECs was analyzed by using tandem mass tag-based quantitative proteomic analysis. Some target proteins were verified by using western blot.

RESULTS

Compared with db/m mice, cardiac microvascular density and left ventricular diastolic function were significantly reduced in db/db mice, and this reduction was attenuated by GCGR mAb treatment. A total of 199 differentially expressed proteins were upregulated in db/db mice versus db/m mice and downregulated in GCGR mAb-treated db/db mice versus db/db mice. The enrichment analysis demonstrated that fatty acid β-oxidation and mitochondrial fusion were the key pathways. The changes of the related proteins carnitine palmitoyltransferase 1B, optic atrophy type 1, and mitofusin-1 were further verified by using western blot. The levels of these three proteins were upregulated in db/db mice, whereas this upregulation was attenuated by GCGR mAb treatment.

CONCLUSION

GCGR antagonism has a protective effect on CMECs and cardiac diastolic function in diabetic mice, and this beneficial effect may be mediated via inhibiting fatty acid β-oxidation and mitochondrial fusion in CMECs.

Advances in smart delivery of magnetic field-targeted drugs in cardiovascular diseases

Magnetic Drug Targeting (MDT) is of particular interest to researchers because of its good loading efficiency, targeting accuracy, and versatile use in vivo. Cardiovascular Disease (CVD) is a global chronic disease with a high mortality rate, and the development of more precise and effective treatments is imminent. A growing number of studies have begun to explore the feasibility of MDT in CVD, but an up-to-date systematic summary is still lacking. This review discusses the current research status of MDT from guiding magnetic fields, magnetic nanocarriers, delivery channels, drug release control, and safety assessment. The current application status of MDT in CVD is also critically introduced. On this basis, new insights into the existing problems and future optimization directions of MDT are further highlighted.

Endothelial cell dysfunction in cardiac disease: driver or consequence?

The vascular endothelium is a multifunctional cellular system which directly influences blood components and cells within the vessel wall in a given tissue. Importantly, this cellular interface undergoes critical phenotypic changes in response to various biochemical and hemodynamic stimuli, driving several developmental and pathophysiological processes. Multiple studies have indicated a central role of the endothelium in the initiation, progression, and clinical outcomes of cardiac disease. In this review we synthesize the current understanding of endothelial function and dysfunction as mediators of the cardiomyocyte phenotype in the setting of distinct cardiac pathologies; outline existing in vivo and in vitro models where key features of endothelial cell dysfunction can be recapitulated; and discuss future directions for development of endothelium-targeted therapeutics for cardiac diseases with limited existing treatment options.

Forkhead box O6 (FoxO6) promotes cardiac pathological remodeling and dysfunction by activating Kif15-TGF-β1 under aggravated afterload

Pathological cardiac hypertrophy exhibits complex and abnormal gene expression patterns and progresses to heart failure. Forkhead box protein O6 (FoxO6) is a key transcription factor involved in many biological processes. This study aimed to explore the role of FoxO6 in cardiac hypertrophy. Three groups of mice were established: wild-type, FoxO6 knockout, and FoxO6-overexpressing. The mice received daily administration of angiotensin-II (Ang-II) or saline for 4 weeks, after which they were examined for cardiac hypertrophy, fibrosis, and function. Elevated cardiac expression of FoxO6 was observed in Ang-II-treated mice. FoxO6 deficiency attenuated contractile dysfunction and cardiac remodeling, including cardiomyocyte hypertrophy and fibroblast proliferation and differentiation. Conversely, FoxO6 overexpression aggravated the cardiomyopathy and heart dysfunction. Further studies identified kinesin family member 15 (Kif15) as downstream molecule of FoxO6. Kif15 inhibition attenuated the aggravating effect of FoxO6 overexpression. In vitro, FoxO6 overexpression increased Kif15 expression in cardiomyocytes and elevated the concentration of transforming growth factor-β1 (TGF-β1) in the medium where fibroblasts were grown, exhibiting increased proliferation and differentiation, while FoxO6 knockdown attenuated this effect. Cardiac-derived FoxO6 promoted pathological cardiac remodeling induced by aggravated afterload largely by activating the Kif15/TGF-β1 axis. This result further complements the mechanisms of communication among different cells in the heart, providing novel therapeutic targets for heart failure.

GPCRs and fibroblast heterogeneity in fibroblast-associated diseases

G protein-coupled receptors (GPCRs) are the largest and most diverse class of signaling receptors. GPCRs regulate many functions in the human body and have earned the title of "most targeted receptors". About one-third of the commercially available drugs for various diseases target the GPCRs. Fibroblasts lay the architectural skeleton of the body, and play a key role in supporting the growth, maintenance, and repair of almost all tissues by responding to the cellular cues via diverse and intricate GPCR signaling pathways. This review discusses the dynamic architecture of the GPCRs and their intertwined signaling in pathological conditions such as idiopathic pulmonary fibrosis, cardiac fibrosis, pancreatic fibrosis, hepatic fibrosis, and cancer as opposed to the GPCR signaling of fibroblasts in physiological conditions. Understanding the dynamics of GPCR signaling in fibroblasts with disease progression can help in the recognition of the complex interplay of different GPCR subtypes in fibroblast-mediated diseases. This review highlights the importance of designing and adaptation of next-generation strategies such as GPCR-omics, focused target identification, polypharmacology, and effective personalized medicine approaches to achieve better therapeutic outcomes for fibrosis and fibrosis associated malignancies.

IL-27 promotes cardiac fibroblast activation and aggravates cardiac remodeling post myocardial infarction

Excessive and chronic inflammation post myocardial infarction (MI) causes cardiac fibrosis and progressive ventricular remodeling, which leads to heart failure. We previously found high levels of IL-27 in the heart and serum until day 14 in murine cardiac ischemia‒reperfusion injury models. However, whether IL-27 is involved in chronic inflammation-mediated ventricular remodeling remains unclear. In the present study, we found that MI triggered high IL-27 expression in murine cardiac macrophages. The increased expression of IL-27 in serum is correlated with cardiac dysfunction and aggravated fibrosis after MI. Furthermore, the addition of IL-27 significantly activated the JAK/STAT signaling pathway in cardiac fibroblasts (CFs). Meanwhile, IL-27 treatment promoted the proliferation, migration and extracellular matrix (ECM) production of CFs induced by angiotensin II (Ang II). Collectively, high levels of IL-27 mainly produced by cardiac macrophages post MI contribute to the activation of CFs and aggravate cardiac fibrosis.

The role of endothelial cell in cardiac hypertrophy: Focusing on angiogenesis and intercellular crosstalk

Cardiac hypertrophy is characterized by cardiac structural remodeling, fibrosis, microvascular rarefaction, and chronic inflammation. The heart is structurally organized by different cell types, including cardiomyocytes, fibroblasts, endothelial cells, and immune cells. These cells highly interact with each other by a number of paracrine or autocrine factors. Cell-cell communication is indispensable for cardiac development, but also plays a vital role in regulating cardiac response to damage. Although cardiomyocytes and fibroblasts are deemed as key regulators of hypertrophic stimulation, other cells, including endothelial cells, also exert important effects on cardiac hypertrophy. More particularly, endothelial cells are the most abundant cells in the heart, which make up the basic structure of blood vessels and are widespread around other cells in the heart, implicating the great and inbuilt advantage of intercellular crosstalk. Cardiac microvascular plexuses are essential for transport of liquids, nutrients, molecules and cells within the heart. Meanwhile, endothelial cell-mediated paracrine signals have multiple positive or negative influences on cardiac hypertrophy. However, a comprehensive discussion of these influences and consequences is required. This review aims to summarize the basic function of endothelial cells in angiogenesis, with an emphasis on angiogenic molecules under hypertrophic conditions. The secondary objective of the research is to fully discuss the key molecules involved in the intercellular crosstalk and the endothelial cell-mediated protective or detrimental effects on other cardiac cells. This review provides a more comprehensive understanding of the overall role of endothelial cells in cardiac hypertrophy and guides the therapeutic approaches and drug development of cardiac hypertrophy.

Transcriptional regulation of macrophages in heart failure

Adverse cardiac remodeling after acute myocardial infarction is the most important pathological mechanism of heart failure and remains a major problem in clinical practice. Cardiac macrophages, derived from tissue resident macrophages and circulating monocyte, undergo significant phenotypic and functional changes following cardiac injury and play crucial roles in inflammatory response and tissue repair response. Currently, numerous studies indicate that epigenetic regulatory factors and transcription factors can regulate the transcription of inflammatory and reparative genes and timely conversion of inflammatory macrophages into reparative macrophages and then alleviate cardiac remodeling. Accordingly, targeting transcriptional regulation of macrophages may be a promising option for heart failure treatment. In this review, we not only summarize the origin and function of cardiac macrophages, but more importantly, describe the transcriptional regulation of macrophages in heart failure, aiming to provide a potential therapeutic target for heart failure.

Big Endothelin-1 as a Predictor of Reverse Remodeling and Prognosis in Dilated Cardiomyopathy

This study aimed to investigate the predictive value of Big endothelin-1(ET-1) for left ventricular reverse remodeling (LVRR) and prognosis in patients with dilated cardiomyopathy (DCM). Patients with DCM and a left ventricular ejection fraction (LVEF) ≤ 50% from 2008 to 2017 were included. LVRR was defined as the LVEF increased by at least 10% or follow-up LVEF increased to at least 50% with a minimum improvement of 5%; meanwhile, the index of left ventricular end-diastolic diameter (LVEDDi) decreased by at least 10% or LVEDDi decreased to ≤33 mm/m². The composite outcome for prognostic analysis consisted of death and heart transplantations. Of the 375 patients included (median age 47 years, 21.1% female), 135 patients (36%) had LVRR after a median of 14 months of treatment. An independent association was found between Big ET-1 at baseline and LVRR in the multivariate model (OR 0.70, 95% CI 0.55-0.89, p = 0.003, per log increase). Big ET-1, body mass index, systolic blood pressure, diagnosis of type 2 diabetes mellitus (T2DM) and treatment with ACEI/ARB were significant predictors for LVRR after stepwise selection. Adding Big ET-1 to the model improved the discrimination (∆AUC = 0.037, p = 0.042 and reclassification (IDI, 3.29%; p = 0.002; NRI, 35%; p = 0.002) for identifying patients with LVRR. During a median follow-up of 39 (27-68) months, Big ET-1 was also independently associated with the composite outcome of death and heart transplantations (HR 1.45, 95% CI 1.13-1.85, p = 0.003, per log increase). In conclusion, Big ET-1 was an independent predictor for LVRR and had prognostic implications, which might help to improve the risk stratification of patients with DCM.

Endothelial-cell-mediated mechanism of coronary microvascular dysfunction leading to heart failure with preserved ejection fraction

Although the prevalence of heart failure with preserved ejection fraction (HFpEF) is growing worldwide, its complex pathophysiology has yet to be fully elucidated, and multiple hypotheses have all failed to produce a viable target for therapeutic action or provide effective treatment. Cardiac remodeling has long been considered an important mechanism of HFpEF. Strong evidence has been reported over the past years that coronary microvascular dysfunction (CMD), manifesting as structural and functional abnormalities of coronary microvasculature, also contributes to the evolution of HFpEF. However, the mechanisms of CMD are still not well understood and need to be studied further. Coronary microvascular endothelial cells (CMECs) are one of the most abundant cell types in the heart by number and active players in cardiac physiology and pathology. CMECs are not only important cellular mediators of cardiac vascularization but also play an important role in disease pathophysiology by participating in the inception and progression of cardiac remodeling. CMECs are also actively involved in the pathogenesis of CMD. Numerous studies have confirmed that CMD is closely related to cardiac remodeling. ECs may serve a critical function in mediating the connection between CMD and HFpEF. It follows that CMECs participate in the mechanism of CMD leading to HFpEF. In this review article, we focus on the role of CMD in the pathogenesis of HFpEF resulting from cardiac remodeling and highlight the subsequent complexity of the EC-mediated correlation between CMD and HFpEF.

Lymphatic endothelial sphingosine 1-phosphate receptor 1 enhances macrophage clearance via lymphatic system following myocardial infarction

Lymphatic endothelial cell homeostasis plays important roles in normal physiological cardiac functions, and its dysfunction significantly influences pathological cardiac remodeling after myocardial infarction (MI). Our results revealed that sphingosine 1-phosphate receptor 1 (S1pr1) expression in cardiac lymphatic endothelial cells (LECs) was sharply changed after MI. It has been shown that S1pr1 tightly controlled LEC functions and homeostasis. We thus hypothesized that lymphatic endothelial S1pr1 might be involved in post-MI cardiac remodeling. We generated LEC-conditional S1pr1 transgenic mice, in which S1pr1 expression was reduced in cardiac LECs. We performed the left anterior descending coronary artery (LAD) ligation operation to induce MI in these mice. Cardiac functions and remodeling were examined by echocardiography analysis and serial histological analysis. Meanwhile, we performed adoptive cell transfer experiments to monitor macrophage trafficking in post-MI myocardium and their draining lymphatic system. Furthermore, in vitro cell culture experiments and mechanism studies were undertaken to uncover the molecular mechanism by which LEC-S1pr1 regulated cardiac inflammation and remodeling after MI. Our results showed that S1pr1 expression significantly decreased in cardiac LECs after MI. Our in vivo experiments showed that the reduced expression of LEC-S1pr1 deteriorated cardiac function and worsened pathological cardiac remodeling after MI. Our further results demonstrated that the reduced expression of LEC-S1pr1 did not influence macrophage infiltration in an early inflammatory phase of MI, but significantly affected macrophages clearance in the later phase of MI via afferent cardiac lymphatics, and thus influenced inflammatory responses and cardiac outcome after MI. Further study showed that S1P/S1pr1 activated ERK signaling pathway and enhanced CCL2 expression, which promoted macrophage trafficking in a paracrine manner. This study reveals that cardiac lymphatic endothelial cells tightly control macrophage trafficking via lymphatic vessels in injured hearts via S1P/S1pr1/ERK/CCL2 pathway and thus regulate post-MI immune modulation and heart repair. This study highlights the importance of cardiac lymphatic vessel system in orchestrating post-MI immune responses and cardiac remodeling by regulating macrophage transit in injured hearts. Our finding implies that a feasible modulation of S1pr1 signaling in LECs might provide a promising target to resolve excessive inflammation and to ameliorate adverse cardiac remodeling after MI.

Endothelial Foxp1 Regulates Neointimal Hyperplasia Via Matrix Metalloproteinase-9/Cyclin Dependent Kinase Inhibitor 1B Signal Pathway

Background The endothelium is essential for maintaining vascular physiological homeostasis and the endothelial injury leads to the neointimal hyperplasia because of the excessive proliferation of vascular smooth muscle cells. Endothelial Foxp1 (forkhead box P1) has been shown to control endothelial cell (EC) proliferation and migration in vitro. However, whether EC-Foxp1 participates in neointimal formation in vivo is not clear. Our study aimed to investigate the roles and mechanisms of EC-Foxp1 in neointimal hyperplasia. Methods and Results The wire injury femoral artery neointimal hyperplasia model was performed in Foxp1 EC-specific loss-of-function and gain-of-function mice. EC-Foxp1 deletion mice displayed the increased neointimal formation through elevation of vascular smooth muscle cell proliferation and migration, and the reduction of EC proliferation hence reendothelialization after injury. In contrast, EC-Foxp1 overexpression inhibited the neointimal formation. EC-Foxp1 paracrine regulated vascular smooth muscle cell proliferation and migration via targeting matrix metalloproteinase-9. Also, EC-Foxp1 deletion impaired EC repair through reduction of EC proliferation via increasing cyclin dependent kinase inhibitor 1B expression. Delivery of cyclin dependent kinase inhibitor 1B-siRNA to ECs using RGD (Arg-Gly-Asp)-peptide magnetic nanoparticle normalized the EC-Foxp1 deletion-mediated impaired EC repair and attenuated the neointimal formation. EC-Foxp1 regulates matrix metalloproteinase-9/cyclin dependent kinase inhibitor 1B signaling pathway to control injury induced neointimal formation. Conclusions Our study reveals that targeting EC-Foxp1-matrix metalloproteinase-9/cyclin dependent kinase inhibitor 1B pathway might provide future novel therapeutic interventions for restenosis.

Endothelial Dysfunction in Heart Failure With Preserved Ejection Fraction: What are the Experimental Proofs?

Heart failure with preserved ejection fraction (HFpEF) has been recognized as the greatest single unmet need in cardiovascular medicine. Indeed, the morbi-mortality of HFpEF is high and as the population ages and the comorbidities increase, so considerably does the prevalence of HFpEF. However, HFpEF pathophysiology is still poorly understood and therapeutic targets are missing. An unifying, but untested, theory of the pathophysiology of HFpEF, proposed in 2013, suggests that cardiovascular risk factors lead to a systemic inflammation, which triggers endothelial cells (EC) and coronary microvascular dysfunction. This cardiac small vessel disease is proposed to be responsible for cardiac wall stiffening and diastolic dysfunction. This paradigm is based on the fact that microvascular dysfunction is highly prevalent in HFpEF patients. More specifically, HFpEF patients have been shown to have decreased cardiac microvascular density, systemic endothelial dysfunction and a lower mean coronary flow reserve. Importantly, impaired coronary microvascular function has been associated with the severity of HF. This review discusses evidence supporting the causal role of endothelial dysfunction in the pathophysiology of HFpEF in human and experimental models.

Substitution of SERCA2 Cys674 aggravates cardiac fibrosis by promoting the transformation of cardiac fibroblasts to cardiac myofibroblasts

Sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase 2 (SERCA2) is vital to maintain intracellular calcium homeostasis, and its redox Cys⁶⁷⁴ (C674) is the key to regulating activity. Our goal was to investigate whether the redox state of SERCA2 C674 is critical for cardiac fibrosis and the mechanisms involved. Heterozygous SERCA2 C674S knock-in (SKI) mice, in which half of C674 was substituted by serine, were used to mimic the partial loss of the reactive C674 thiol in pathological conditions. In cardiac fibroblasts, the substitution of C674 thiol increased Ca²⁺ levels in cytoplasm and mitochondria, and intracellular ROS levels, and activated calcineurin/nuclear factor of activated T-lymphocytes (NFAT) pathway, increased the protein expression of profibrotic factors TGF beta 1 (TGF-β1), alpha smooth muscle actin, collagen I and collagen III, and promoted the transformation of cardiac fibroblasts to cardiac myofibroblasts, which could be reversed by calcineurin/NFAT inhibitor, SERCA2 agonist, or ROS scavenger. Activation of SERCA2 or scavenging ROS is beneficial to alleviate cardiac fibrosis caused by the substitution of C674. In conclusion, the partial loss of the reactive C674 thiol in the SERCA2 exacerbates cardiac fibrosis by activating the calcineurin/NFAT/TGF-β1 pathway to promote the transformation of cardiac fibroblasts to cardiac myofibroblasts, which highlights the importance of C674 redox state in maintaining the homeostasis of cardiac fibroblasts. SERCA2 is a potential therapeutic target for the treatment of cardiac fibrosis.

Endothelial S1pr2 regulates post-ischemic angiogenesis via AKT/eNOS signaling pathway

Aims: It is important to understand the mechanism that regulates post-ischemic angiogenesis and to explore a new therapeutic target for an effective improvement of revascularization in peripheral artery disease (PAD) patients. Post-ischemic angiogenesis is a highly orchestrated process, which involves vascular endothelial cells (ECs) proliferation, migration and assembly into capillaries. We found a significant reduction of S1pr2 (sphingosine 1-phosphate receptor 2) in endothelial cells after hindlimb ischemia (HLI). We thus hypothesized that EC-S1pr2 might be involved in the regulation of post-ischemic angiogenesis and blood flow recovery during peripheral arterial disease (PAD). Methods and Results: We generated both EC-specific S1pr2 loss-of-function and S1pr2 gain-of-function mice. Our study showed that EC-specific S1pr2 loss-of-function significantly enhanced post-ischemic angiogenesis and improved blood flow recovery upon femoral artery ligation, whereas the EC-specific S1pr2 gain-of-function severely hindered post-ischemic angiogenesis and reduced blood flow recovery in ischemic limbs. We next identified that S1pr2 inhibited AKT/eNOS signaling pathway, and thus inhibited EC proliferation/migration and angiogenic activity. As expected, pharmacological inhibition of S1pr2 by JTE013 improved post-ischemic angiogenesis and improved blood flow perfusion after femoral artery ligation. Moreover, we developed RGD-peptide magnetic nanoparticles packaging S1pr2-siRNA which specifically targeted ECs and achieved an efficient silencing of S1pr2 expression in ECs in vivo. This EC-targeted strategy to dampen S1pr2 significantly enhanced post-ischemic angiogenesis and boosted blood perfusion after HLI, supplying a novel therapy target for patients with peripheral arterial disease. Conclusions: This present study demonstrates that EC-expressing S1pr2 tightly controls post-ischemic angiogenesis and blood flow perfusion recovery. This research provides a novel strategy for EC-target knockdown of S1pr2 as a new therapeutic intervention for patients with peripheral artery disease.

Anti-Arrhythmic Effects of Sodium-Glucose Co-Transporter 2 Inhibitors

Arrhythmias are clinically prevalent with a high mortality rate. They impose a huge economic burden, thereby substantially affecting the quality of life. Sodium-glucose co-transporter 2 inhibitor (SGLT2i) is a new type of hypoglycemic drug, which can regulate blood glucose level safely and effectively. Additionally, it reduces the occurrence and progression of heart failure and cardiovascular events significantly. Recently, studies have found that SGLT2i can alleviate the occurrence and progression of cardiac arrhythmias; however, the exact mechanism remains unclear. In this review, we aimed to discuss and summarize new literature on different modes in which SGLT2i ameliorates the occurrence and development of cardiac arrhythmias.

Transcription factor FOXP1 mediates vascular endothelial dysfunction in diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is still the fastest growing cause of blindness in working aged adults, and its typical characteristics are endothelial cell dysfunction and pericytes loss. Transcription factor fork head box P1 (FOXP1) is a member of FOX family involved in diabetes progression and is expressed in endothelial cells. The purpose of this study was to investigate the role and mechanism of FOXP1 in DR.

METHODS

The vitreous of DR patients and non-DR patients were collected, and the expression of FOXP1 was detected by real-time polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) cultured in high glucose simulated DR environment, and the expressions of FOXP1, vascular endothelial growth factor (VEGF), and pigment epithelium derived factor (PEDF) were detected by RT-qPCR and western blot (WB) after transfection of small interfering RNA (siRNA) to knock out FOXP1. At the same time, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (MTT), 5-ethynyl-2'-deoxyuridine assay (EDU), flow cytometry, Transwell assay, and tube-forming experiment were performed to determine cell proliferation, migration, and tube-forming ability.

RESULTS

We found that FOXP1 was highly expressed in the vitreous of DR patients and HUVECs under high glucose condition. After FOXP1 was decreased, the activation of VEGF expression and inhibition of PEDF expression in HUVECs induced by high glucose were reversed; meanwhile, cell proliferation, migration, and tube formation decreased, and apoptosis was promoted.

CONCLUSION

Generally, FOXP1 is highly expressed in the vitreous of DR patients, and its silence prevented VEGF/PEDF signaling pathway stimulated by high glucose and also reduced the proliferation, migration, and tube formation of endothelial cell, thus improving vascular endothelial dysfunction caused by DR. The results indicate that FOXP1 may be a therapeutic target of DR.

Pentraxin 3 depletion (PTX3 KD) inhibited myocardial fibrosis in heart failure after myocardial infarction

Background: HF is a common complication of MI. The underlying mechanisms of myocardial fibrosis in HF after MI are incompletely defined. Here, this study aims to investigate the role of PTX3 KD in HF after MI.

Methods: Bioinformatics analysis based on GSE86569 dataset was performed to explore the potential role of PTX3 in HF. Male C57/BL6J mice were administered with lentiviral vector encoding PTX3 KD or empty vector, and then underwent either coronary ligation or sham surgery. Echocardiography, Masson staining, and immunofluorescence counterstaining were conducted to evaluate the cardiac function and fibrosis. Cardiac fibroblasts were isolated and transfected with lentiviral vector encoding PTX3 KD in vitro to verify the in vivo findings.

Results: Bioinformatics analysis based on GSE86569 revealed the aberrant expression of PTX3 in HF patients. Echocardiography showed that PTX3 KD reversed the HF-induced cardiac dysfunction with better cardiac function parameters. Masson staining demonstrated that the obvious infarct and high fibrosis ratio in HF mice were remarkably improved after PTX3 KD. Immunofluorescence staining indicated that the HF-induced increase expression of α-SMA was significantly suppressed by PTX3 KD. Additionally, both in vivo and in vitro results confirmed that PTX3 KD decreased the fibrosis-related up-regulation of collagen I, collagen III, and p-STAT3. However, the result was opposite after IL-6 treatment.

Conclusions: PTX3 KD protects the cardiac function and counteracts the myocardial fibrosis by down-regulating IL-6/STAT3 pathway in HF.

Elabela alleviates ferroptosis, myocardial remodeling, fibrosis and heart dysfunction in hypertensive mice by modulating the IL-6/STAT3/GPX4 signaling

Hypertension-mediated pathological cardiac remodeling often progresses to heart failure. Elabela, mainly expressed in the cardiac microvascular endothelial cells (CMVECs), functions as a new endogenous ligand for apelin receptor. However, the exact roles of elabela in hypertension remain largely unclear. In this study, 10-week-old male C57BL/6 mice were randomly subjected to infusion of angiotensin (Ang) II (1.5 mg/kg/d) or saline for 2 weeks. Ang II infusion led to marked increases in systolic blood pressure levels and reduction of elabela levels in hypertensive mice with augmented myocardial hypertrophy and fibrosis. Furthermore, administration of elabela or ferroptosis inhibitor ferrostatin-1 significantly prevented Ang II-mediated pathological myocardial remodeling, dysfunction, and ultrastructural injury in hypertensive mice with downregulated expression of inflammation-, hypertrophy-, and fibrosis-related genes. Notably, elabela strikingly alleviated Ang II-induced upregulation of iron levels and lipid peroxidation in hypertensive mice by suppressing cardiac interleukin-6 (IL-6)/STAT3 signaling and activating the xCT/glutathione peroxidase (GPX4) signaling. In cultured CMVECs, exposure to Ang II resulted in a marked decrease in elabela levels and obvious increases in cellular ferroptosis, proliferation, inflammation, and superoxide production, which were rescued by elabela or ferrostatin-1 while were blocked by co-treatment with rhIL-6. Furthermore, knockdown of elabela by siRNA in CMVECs contributed to Ang II-mediated augmentations in cellular proliferation, migration, and oxidative stress in cultured cardiac fibroblasts and cardiomyocytes, respectively. In conclusion, elabela antagonizes Ang II-mediated promotion of CMVECs ferroptosis, adverse myocardial remodeling, fibrosis and heart dysfunction through modulating the IL-6/STAT3/GPX4 signaling pathway. Targeting elabela-APJ axis serves as a novel strategy for hypertensive heart diseases.

Untargeted sequencing of circulating microRNAs in a healthy and diseased older population

We performed untargeted profiling of circulating microRNAs (miRNAs) in a well characterized cohort of older adults to verify associations of health and disease-related biomarkers with systemic miRNA expression. Differential expression analysis revealed 30 miRNAs that significantly differed between healthy active, healthy sedentary and sedentary cardiovascular risk patients. Increased expression of miRNAs miR-193b-5p, miR-122-5p, miR-885-3p, miR-193a-5p, miR-34a-5p, miR-505-3p, miR-194-5p, miR-27b-3p, miR-885-5p, miR-23b-5b, miR-365a-3p, miR-365b-3p, miR-22-5p was associated with a higher metabolic risk profile, unfavourable macro- and microvascular health, lower physical activity (PA) as well as cardiorespiratory fitness (CRF) levels. Increased expression of miR-342-3p, miR-1-3p, miR-92b-5p, miR-454-3p, miR-190a-5p and miR-375-3p was associated with a lower metabolic risk profile, favourable macro- and microvascular health as well as higher PA and CRF. Of note, the first two principal components explained as much as 20% and 11% of the data variance. miRNAs and their potential target genes appear to mediate disease- and health-related physiological and pathophysiological adaptations that need to be validated and supported by further downstream analysis in future studies.

Clinical Trial Registration: ClinicalTrials.gov: NCT02796976 (https://clinicaltrials.gov/ct2/show/NCT02796976).

LncRNA ROR promotes NLRP3-mediated cardiomyocyte pyroptosis by upregulating FOXP1 via interactions with PTBP1

OBJECTIVE

The purpose of this design was to explore the specific role and related mechanism of long noncoding RNA (lncRNA) regulators of reprogramming (ROR) in viral myocarditis (VMC).

METHODS

AC16 cells were infected with coxsackievirus B3 (CVB3) to establish a VMC cell model in vitro. The release of interleukin (IL)-1β and IL-18 was evaluated by enzyme-linked immunosorbent assay (ELISA). Gene expression was calculated using quantitative real-time (qRT)-PCR. Cell pyroptosis was determined by flow cytometry and Western blot assays. Cell counting Kit-8 (CCK-8) detected cell viability. The molecular associations were verified by employing RNA immunoprecipitation (RIP), RNA pulldown and chromatin immunoprecipitation (ChIP) assays.

RESULTS

The lncRNA ROR was more highly expressed in CVB3 virus-infected AC16 cells than in controls. Knockdown of ROR markedly rescued cell viability and reduced the release of IL-1β and IL-18, cell pyroptosis and pyroptotic proteins such as NLRP3, ASC and cleaved caspase 1. Mechanistically, ROR destroyed the mRNA stability of Forkhead Box P Factor 1 (FOXP1) by binding polypyrimidine tract binding protein 1 (PTBP1). FOXP1 repressed the transcription of NLRP3 by directly interacting with its promoter. Importantly, coinhibition of FOXP1 impeded the protective role of ROR silencing in CVB3-infected AC16 cells.

CONCLUSION

In conclusion, these findings elucidated that ROR knockdown inhibited CVB3-induced cardiomyocyte inflammation and NLRP3-mediated pyroptosis by regulating the PTBP1/FOXP1 axis, implying that ROR might be a new inducer in CVB3-infected VMC.

FSTL1-USP10-Notch1 Signaling Axis Protects Against Cardiac Dysfunction Through Inhibition of Myocardial Fibrosis in Diabetic Mice

The incidence of type 2 diabetes mellitus (T2DM) has been increasing globally, and T2DM patients are at an increased risk of major cardiac events such as myocardial infarction (MI). Nevertheless, the molecular mechanisms underlying MI injury in T2DM remain elusive. Ubiquitin-specific protease 10 (USP10) functions as a NICD1 (Notch1 receptor) deubiquitinase that fine-tunes the essential myocardial fibrosis regulator Notch signaling. Follistatin-like protein 1 (FSTL1) is a cardiokine with proven benefits in multiple pathological processes including cardiac fibrosis and insulin resistance. This study was designed to examine the roles of FSTL1/USP10/Notch1 signaling in MI-induced cardiac dysfunction in T2DM. High-fat-diet-treated, 8-week-old C57BL/6J mice and db/db T2DM mice were used. Intracardiac delivery of AAV9-FSTL1 was performed in T2DM mice following MI surgery with or without intraperitoneal injection of crenigacestat (LY3039478) and spautin-1. Our results demonstrated that FSTL1 improved cardiac function following MI under T2DM by reducing serum lactate dehydrogenase (LDH) and myocardial apoptosis as well as cardiac fibrosis. Further in vivo studies revealed that the protective role of FSTL1 against MI injury in T2DM was mediated by the activation of USP10/Notch1. FSTL1 protected cardiac fibroblasts (CFs) against DM-MI-induced cardiofibroblasts injury by suppressing the levels of fibrosis markers, and reducing LDH and MDA concentrations in a USP10/Notch1-dependent manner. In conclusion, FSTL1 treatment ameliorated cardiac dysfunction in MI with co-existent T2DM, possibly through inhibition of myocardial fibrosis and apoptosis by upregulating USP10/Notch1 signaling. This finding suggests the clinical relevance and therapeutic potential of FSTL1 in T2DM-associated MI and other cardiovascular diseases.

The Impact of Inflammatory Immune Reactions of the Vascular Niche on Organ Fibrosis

Inflammation is a type of defense response against tissue damage, and can be mediated by lymphocytes and macrophages. Fibrosis is induced by tissue injury and inflammation, which leads to an increase in fibrous connective tissue in organs and a decrease in organ parenchyma cells, finally leading to organ dysfunction or even failure. The vascular niche is composed of endothelial cells, pericytes, macrophages, and hematopoietic stem cells. It forms a guiding microenvironment for the behavior of adjacent cells, and mainly exists in the microcirculation, including capillaries. When an organ is damaged, the vascular niche regulates inflammation and affects the repair of organ damage in a variety of ways, such as via its angiocrine function and transformation of myofibroblasts. In this paper, the main roles of vascular niche in the process of organ fibrosis and its mechanism of promoting the progress of fibrosis through inflammatory immunoregulation are summarized. It was proposed that the vascular niche should be regarded as a new therapeutic target for organ fibrosis, suggesting that antifibrotic effects could be achieved by regulating macrophages, inhibiting endothelial-mesenchymal transition, interfering with the angiocrine function of endothelial cells, and inhibiting the transformation of pericytes into myofibroblasts, thus providing new ideas for antifibrosis drug research.

The effect of immune cell-derived exosomes in the cardiac tissue repair after myocardial infarction: Molecular mechanisms and pre-clinical evidence

After a myocardial infarction (MI), the inflammatory responses are induced and assist to repair ischaemic injury and restore tissue integrity, but excessive inflammatory processes promote abnormal cardiac remodelling and progress towards heart failure. Thus, a timely resolution of inflammation and a firmly regulated balance between regulatory and inflammatory mechanisms can be helpful. Molecular- and cellular-based approaches modulating immune response post-MI have emerged as a promising therapeutic strategy. Exosomes are essential mediators of cell-to-cell communications, which are effective in modulating immune responses and immune cells following MI, improving the repair process of infarcted myocardium and maintaining ventricular function via the crosstalk among immune cells or between immune cells and myocardial cells. The present review aimed to seek the role of immune cell-secreted exosomes in infarcted myocardium post-MI, together with mechanisms behind their repairing impact on the damaged myocardium. The exosomes we focus on are secreted by classic immune cells including macrophages, dendritic cells, regulatory T cells and CD4+ T cells; however, further research is demanded to determine the role of exosomes secreted by other immune cells, such as B cells, neutrophils and mast cells, in infarcted myocardium after MI. This knowledge can assist in the development of future therapeutic strategies, which may benefit MI patients.

Targeting fibrosis in the failing heart with nanoparticles

Heart failure (HF) is a clinical syndrome characterized by typical symptoms and signs caused by a structural and/or functional cardiac abnormality, resulting in a reduced cardiac output and/or elevated intracardiac pressures at rest or during stress. Due to increasing incidence, prevalence and, most importantly mortality, HF is a healthcare burden worldwide, despite the improvement of treatment options and effectiveness. Acute and chronic cardiac injuries trigger the activation of neurohormonal, inflammatory, and mechanical pathways ultimately leading to fibrosis, which plays a key role in the development of cardiac dysfunction and HF. The use of nanoparticles for targeted drug delivery would greatly improve therapeutic options to identify, prevent and treat cardiac fibrosis. In this review we will highlight the mechanisms of cardiac fibrosis development to depict the pathophysiological features for passive and active targeting of acute and chronic cardiac fibrosis with nanoparticles. Then we will discuss how cardiomyocytes, immune and inflammatory cells, fibroblasts and extracellular matrix can be targeted with nanoparticles to prevent or restore cardiac dysfunction and to improve the molecular imaging of cardiac fibrosis.

Nanomedicine for the treatment of diabetes-associated cardiovascular diseases and fibrosis

Cardiomyopathy and fibrosis are the main causes of heart failure in diabetes patients. For therapeutic purposes, a delivery system is required to enhance antidiabetic drug efficacy and specifically target profibrotic pathways in cardiomyocytes. Nanoparticles (NPs) have distinct advantages, including biocompatibility, bioavailability, targeting efficiency, and minimal toxicity, which make them ideal for antidiabetic treatment. In this review, we overview the latest information on the pathogenesis of cardiomyopathy and fibrosis in diabetes patients. We summarize how NP applications improve insulin and liraglutide efficacy and their sustained release upon oral administration. We provide a comprehensive review of the results of NP clinical trials in diabetes patients and of animal studies investigating the effects of NP-mediated anti-fibrotic treatments. Collectively, the application of advanced NP delivery systems in the treatment of cardiomyopathy and fibrosis in diabetes patients is a promising and innovative therapeutic strategy.

Qindan Capsule Attenuates Myocardial Hypertrophy and Fibrosis in Pressure Overload-Induced Mice Involving mTOR and TGF-β1/Smad Signaling Pathway Inhibition

Qindan capsule (QC), a traditional Chinese medicine compound, has been used to treat hypertension in the clinic for over 30 years. It is still not known about the effects of QC on pressure overload-induced cardiac remodeling. Hence, this study aims to investigate the effects of QC on pressure overload-induced cardiac hypertrophy, fibrosis, and heart failure in mice and to determine the possible mechanisms. Transverse aortic constriction (TAC) surgery was used to induce cardiac hypertrophy and heart failure in C57BL/6 mice. Mice were treated with QC or losartan for 8 weeks after TAC surgery. Cardiac function indexes were evaluated with transthoracic echocardiography. Cardiac pathology was detected using HE and Masson's trichrome staining. Cardiomyocyte ultrastructure was detected using transmission electron microscopy. Hypertrophy-related fetal gene expression was investigated using real-time RT-PCR. The expression of 8-OHdG and the concentration of MDA and Ang-II were assessed by immunohistochemistry stain and ELISA assay, respectively. The total and phosphorylated protein levels of mTOR, p70S6K, 4EBP1, Smad2, and Smad3 and the expression of TGF-β1 and collagen I were measured using western blot. The results showed that low- and high-dose QC improved pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction. QC inhibited ANP, BNP, and β-MHC mRNA expression in failing hearts. QC improved myocardial ultrastructure after TAC surgery. Furthermore, QC downregulated the expression of 8-OHdG and the concentration of MDA, 15-F_2t-IsoP, and Ang-II in heart tissues after TAC surgery. We also found that QC inhibited the phosphorylation of mTOR, p70S6K, and 4EBP1 and the expression of TGF-β1, p-Smad2, p-Smad3, and collagen I in pressure overload-induced failing hearts. These data indicate that QC has direct benefic effects on pressure overload-induced cardiac hypertrophy, fibrosis, and dysfunction. The protective effects of QC involve prevention of increased oxidative stress injury and Ang-II levels and inhibition of mTOR and TGF-β1/Smad pathways in failing hearts.

Krüppel-Like Factor 15 Modulates CXCL1/CXCR2 Signaling-Mediated Inflammatory Response Contributing to Angiotensin II-Induced Cardiac Remodeling

Inflammation is involved in cardiac remodeling. In response to pathological stimuli, activated cardiac fibroblasts (CFs) secreting inflammatory cytokines and chemokines play an important role in monocyte/macrophage recruitment. However, the precise mechanism of CF-mediated inflammatory response in hypertension-induced cardiac remodeling remains unclear. In the present study, we investigated the role of transcription factor Krüppel-like factor 15 (KLF15) in this process. We found that KLF15 expression decreased while chemokine CXCL1 and its receptor CXCR2 expression increased in the hearts of angiotensin II (Ang II)-infused mice. Compared to the wild-type mice, KLF15 knockout (KO) mice aggravated Ang II-induced cardiac hypertrophy and fibrosis. Deficiency of KLF15 promoted macrophage accumulation, increase of CXCL1 and CXCR2 expression, and mTOR, ERK1/2, NF-κB-p65 signaling activation in the hearts. Mechanistically, Ang II dose- dependently decreased KLF15 expression and increased CXCL1 secretion from cardiac fibroblasts but not cardiac myoblasts. Loss- or gain-of-function studies have shown that KLF15 negatively regulated CXCL1 expression through its transactivation domain (TAD). Intriguingly, the adenovirus-mediated full length of KLF15—but not KLF15 with TAD deletion overexpression—markedly prevented pathological change in Ang II-infused mice. Notably, the administration of CXCR2 inhibitor SB265610 reversed KLF15 knockout-mediated aggravation of cardiac dysfunction, remodeling, and inflammation induced by Ang II. In conclusion, our study identifies that KLF15 in cardiac fibroblasts negatively regulates CXCL1/CXCR2 axis-mediated inflammatory response and subsequent cardiac remodeling in hypertension.

The NLRP3 inflammasome: Multiple activation pathways and its role in primary cells during ventricular remodeling

Inflammasomes are a group of multiprotein signaling complexes located in the cytoplasm. Several inflammasomes have been identified, including NLRP1, NLRP2, NLRP3, AIM2, and NLRC4. Among them, NLRP3 was investigated in most detail, and it was reported that it can be activated by many different stimuli. Increased NLRP3 protein expression and inflammasome assembly lead to caspase-1 mediated maturation and release of IL-1β, which triggers inflammation and pyroptosis. The activation of the NLRP3 inflammasome has been widely reported in studies of tumors and neurological diseases, but relatively few studies on the cardiovascular system. Ventricular remodeling (VR) is an important factor contributing to heart failure (HF) after myocardial infarction (MI). Consequently, delaying VR is of great significance for improving heart function. Studies have shown that the NLRP3 inflammasome plays an essential role in the process of VR. Here, we reviewed the latest studies on the activation pathway of the NLRP3 inflammasome, focusing on the effects of the NLRP3 inflammasome in primary cells during VR, and finally discuss future research directions in this field.

Endothelial ERG alleviates cardiac fibrosis via blocking endothelin-1-dependent paracrine mechanism

Cardiac endothelium communicates closely with adjacent cardiac cells by multiple cytokines and plays critical roles in regulating fibroblasts proliferation, activation, and collagen synthesis during cardiac fibrosis. E26 transformation-specific (ETS)-related gene (ERG) belongs to the ETS transcriptional factor family and is required for endothelial cells (ECs) homeostasis and cardiac development. This study aims at investigating the potential role and molecular basis of ERG in fibrotic remodeling within the adult heart. We observed that ERG was abundant in murine hearts, especially in cardiac ECs, but decreased during cardiac fibrosis. ERG knockdown within murine hearts caused spontaneously cardiac fibrosis and dysfunction, accompanied by the activation of multiple Smad-dependent and independent pathways. However, the direct silence of ERG in cardiac fibroblasts did not affect the expression of fibrotic markers. Intriguingly, ERG knockdown in human umbilical vein endothelial cells (HUVECs) promoted the secretion of endothelin-1 (ET-1), which subsequently accelerated the proliferation, phenotypic transition, and collagen synthesis of cardiac fibroblasts in a paracrine manner. Suppressing ET-1 with either a neutralizing antibody or a receptor blocker abolished ERG knockdown-mediated deleterious effect in vivo and in vitro. This pro-fibrotic effect was also negated by RGD (Arg-Gly-Asp)-peptide magnetic nanoparticles target delivery of ET-1 small interfering RNA to ECs in mice. More importantly, we proved that endothelial ERG overexpression notably prevented pressure overload-induced cardiac fibrosis. Collectively, endothelial ERG alleviates cardiac fibrosis via blocking ET-1-dependent paracrine mechanism and it functions as a candidate for treating cardiac fibrosis. • ERG is abundant in murine hearts, especially in cardiac ECs, but decreased during fibrotic remodeling. • ERG knockdown causes spontaneously cardiac fibrosis and dysfunction. • ERG silence in HUVECs promotes the secretion of endothelin-1, which in turn activates cardiac fibroblasts in a paracrine manner. • Endothelial ERG overexpression prevents pressure overload-induced cardiac fibrosis.

Endothelial Klf2-Foxp1-TGFβ signal mediates the inhibitory effects of simvastatin on maladaptive cardiac remodeling

Aims: Pathological cardiac fibrosis and hypertrophy are common features of left ventricular remodeling that often progress to heart failure (HF). Endothelial cells (ECs) are the most abundant non-myocyte cells in adult mouse heart. Simvastatin, a strong inducer of Krüppel-like Factor 2 (Klf2) in ECs, ameliorates pressure overload induced maladaptive cardiac remodeling and dysfunction. This study aims to explore the detailed molecular mechanisms of the anti-remodeling effects of simvastatin.

Methods and Results: RGD-magnetic-nanoparticles were used to endothelial specific delivery of siRNA and we found absence of simvastatin's protective effect on pressure overload induced maladaptive cardiac remodeling and dysfunction after in vivo inhibition of EC-Klf2. Mechanism studies showed that EC-Klf2 inhibition reversed the simvastatin-mediated reduction of fibroblast proliferation and myofibroblast formation, as well as cardiomyocyte size and cardiac hypertrophic genes, which suggested that EC-Klf2 might mediate the anti-fibrotic and anti-hypertrophy effects of simvastatin. Similar effects were observed after Klf2 inhibition in cultured ECs. Moreover, Klf2 regulated its direct target gene TGFβ1 in ECs and mediated the protective effects of simvastatin, and inhibition of EC-Klf2 increased the expression of EC-TGFβ1 leading to simvastatin losing its protective effects. Also, EC-Klf2 was found to regulate EC-Foxp1 and loss of EC-Foxp1 attenuated the protective effects of simvastatin similar to EC-Klf2 inhibition.

Conclusions: We conclude that cardiac microvasculature ECs are important in the modulation of pressure overload induced maladaptive cardiac remodeling and dysfunction, and the endothelial Klf2-TGFβ1 or Klf2-Foxp1-TGFβ1 pathway mediates the preventive effects of simvastatin. This study demonstrates a novel mechanism of the non-cholesterol lowering effects of simvastatin for HF prevention.

Role of TRPM7 in cardiac fibrosis: A potential therapeutic target (Review)

Cardiac fibrosis is a hallmark of cardiac remodeling associated with nearly all forms of heart disease. Clinically, no effective therapeutic drugs aim to inhibit cardiac fibrosis, owing to the complex etiological heterogeneity and pathogenesis of this disease. A two-in-one protein structure, a ubiquitous expression profile and unique biophysical characteristics enable the involvement of transient receptor potential melastatin-subfamily member 7 (TRPM7) in the pathogenesis and development of fibrosis-related cardiac diseases, such as heart failure (HF), cardiomyopathies, arrhythmia and hyperaldosteronism. In response to a variety of stimuli, multiple bioactive molecules can activate TRPM7 and related signaling pathways, leading to fibroblast proliferation, differentiation and extracellular matrix production in cardiac fibroblasts. TRPM7-mediated Ca²⁺ signaling and TGF-β1 signaling pathways are critical for the formation of fibrosis. Accumulating evidence has demonstrated that TRPM7 is a potential pharmacological target for halting the development of fibrotic cardiac diseases. Reliable drug-like molecules for further development of high-affinity in vivo drugs targeting TRPM7 are urgently needed. The present review discusses the widespread and significant role of TRPM7 in cardiac fibrosis and focuses on its potential as a therapeutic target for alleviating heart fibrogenesis.

Elevated MicroRNA 183 Impairs Trophoblast Migration and Invasiveness by Downregulating FOXP1 Expression and Elevating GNG7 Expression during Preeclampsia

Preeclampsia (PE) is a hypertensive disorder of uncertain etiology that is the leading cause of maternal and fetal morbidity or mortality. The dysregulation of microRNAs (miRNAs) has been highlighted as a potential factor involved in the development of PE. Therefore, our study investigated a novel miRNA, miRNA 183 (miR-183), and its underlying association with PE. Expression of miR-183, forkhead box P1 (FOXP1), and G protein subunit gamma 7 (GNG7) in placental tissues of patients with PE was determined. Gain- and loss-of-function experiments were conducted to explore modulatory effects of miR-183, FOXP1, and GNG7 on the viability, invasion, and angiogenesis of trophoblast cells in PE. Finally, we undertook in vivo studies to explore effects of FOXP1 in the PE model. The results revealed suppressed expression of FOXP1 and significant elevations in miR-183 and GNG7 expression in placental tissues of PE patients. FOXP1 was observed to promote proliferation, invasion, and angiogenesis in human chorionic trophoblastic cells. miR-183 resulted in depletion of FOXP1 expression, while FOXP1 was capable of restraining GNG7 expression and promoting the mTOR pathway. The findings confirmed the effects of FOXP1 on PE. In conclusion, miR-183 exhibits an inhibitory role in PE through suppression of FOXP1 and upregulation of GNG7.

Role of IgE-FcεR1 in Pathological Cardiac Remodeling and Dysfunction

BACKGROUND

Immunoglobulin E (IgE) belongs to a class of immunoglobulins involved in immune response to specific allergens. However, the roles of IgE and IgE receptor (FcεR1) in pathological cardiac remodeling and heart failure are unknown.

METHODS

Serum IgE levels and cardiac FcεR1 expression were assessed in diseased hearts from human and mouse. The role of FcεR1 signaling in pathological cardiac remodeling was explored in vivo by FcεR1 genetic depletion, anti-IgE antibodies, and bone marrow transplantation. The roles of the IgE-FcεR1 pathway were further evaluated in vitro in primary cultured rat cardiomyocytes and cardiac fibroblasts (CFs). RNA sequencing and bioinformatic analyses were used to identify biochemical changes and signaling pathways that are regulated by IgE/FcεR1.

RESULTS

Serum IgE levels were significantly elevated in patients with heart failure as well as in 2 mouse cardiac disease models induced by chronic pressure overload via transverse aortic constriction and chronic angiotensin II infusion. Interestingly, FcεR1 expression levels were also significantly upregulated in failing hearts from human and mouse. Blockade of the IgE-FcεR1 pathway by FcεR1 knockout alleviated transverse aortic constriction- or angiotensin II-induced pathological cardiac remodeling or dysfunction. Anti-IgE antibodies (including the clinical drug omalizumab) also significantly alleviated angiotensin II-induced cardiac remodeling. Bone marrow transplantation experiments indicated that IgE-induced cardiac remodeling was mediated through non-bone marrow-derived cells. FcεR1 was found to be expressed in both cardiomyocytes and CFs. In cultured rat cardiomyocytes, IgE-induced cardiomyocyte hypertrophy and hypertrophic marker expression were abolished by depleting FcεR1. In cultured rat CFs, IgE-induced CF activation and matrix protein production were also blocked by FcεR1 deficiency. RNA sequencing and signaling pathway analyses revealed that transforming growth factor-β may be a critical mediator, and blocking transforming growth factor-β indeed alleviated IgE-induced cardiomyocyte hypertrophy and cardiac fibroblast activation in vitro.

CONCLUSIONS

Our findings suggest that IgE induction plays a causative role in pathological cardiac remodeling, at least partially via the activation of IgE-FcεR1 signaling in cardiomyocytes and CFs. Therapeutic strategies targeting the IgE-FcεR1 axis may be effective for managing IgE-mediated cardiac remodeling.

Cardiac fibrosis

Myocardial fibrosis, the expansion of the cardiac interstitium through deposition of extracellular matrix proteins, is a common pathophysiologic companion of many different myocardial conditions. Fibrosis may reflect activation of reparative or maladaptive processes. Activated fibroblasts and myofibroblasts are the central cellular effectors in cardiac fibrosis, serving as the main source of matrix proteins. Immune cells, vascular cells and cardiomyocytes may also acquire a fibrogenic phenotype under conditions of stress, activating fibroblast populations. Fibrogenic growth factors (such as transforming growth factor-β and platelet-derived growth factors), cytokines [including tumour necrosis factor-α, interleukin (IL)-1, IL-6, IL-10, and IL-4], and neurohumoral pathways trigger fibrogenic signalling cascades through binding to surface receptors, and activation of downstream signalling cascades. In addition, matricellular macromolecules are deposited in the remodelling myocardium and regulate matrix assembly, while modulating signal transduction cascades and protease or growth factor activity. Cardiac fibroblasts can also sense mechanical stress through mechanosensitive receptors, ion channels and integrins, activating intracellular fibrogenic cascades that contribute to fibrosis in response to pressure overload. Although subpopulations of fibroblast-like cells may exert important protective actions in both reparative and interstitial/perivascular fibrosis, ultimately fibrotic changes perturb systolic and diastolic function, and may play an important role in the pathogenesis of arrhythmias. This review article discusses the molecular mechanisms involved in the pathogenesis of cardiac fibrosis in various myocardial diseases, including myocardial infarction, heart failure with reduced or preserved ejection fraction, genetic cardiomyopathies, and diabetic heart disease. Development of fibrosis-targeting therapies for patients with myocardial diseases will require not only understanding of the functional pluralism of cardiac fibroblasts and dissection of the molecular basis for fibrotic remodelling, but also appreciation of the pathophysiologic heterogeneity of fibrosis-associated myocardial disease.