From Inflammation to Fibrosis-Molecular and Cellular Mechanisms of Myocardial Tissue Remodelling and Perspectives on Differential Treatment Opportunities

Increased epicardial adipose tissue is associated with left atrial mechanical dysfunction in patients with heart failure with mildly reduced and preserved ejection fraction

INTRODUCTION

Heart failure (HF) with mildly reduced and preserved ejection fraction (HFmrEF/HFpEF) is often accompanied by atrial dysfunction. It has been suggested that specific ectopic fat depots, such as epicardial adipose tissue (EAT), may directly influence the myocardial cells and, therefore, be involved in the pathophysiology of atrial mechanical dysfunction. In this study, we aimed to investigate the association between EAT and left atrial (LA) mechanical dysfunction.

METHODS AND RESULTS

In total, 82 patients with symptomatic HF and left ventricular ejection fraction > 40% were prospectively enrolled. All patients underwent CMR while in sinus rhythm. LA mechanical dysfunction was defined as the presence of LA end-systolic volume index > 52 mL/m2 and LA reservoir strain < 23%. EAT volume was indexed for body surface area. Mean age was 69 ± 10 years, 42 (51%) were women and mean body mass index (BMI) was 29 ± 6 kg/m2. Mean LVEF was 55 ± 9% and 34 (41%) patients had LA mechanical dysfunction. In patients with LA mechanical dysfunction, the EAT volume was significantly higher than in patients without LA mechanical dysfunction (90 vs 105 mL/m2, p = 0.02) while BMI was similar. In multivariable logistic regression analyses, increased EAT remained significantly associated with LA mechanical dysfunction (OR 1.31, 95% CI 1.03-1.66, p = 0.03).

CONCLUSION

Increased EAT was associated with LA mechanical dysfunction in patients with HFmrEF and HFpEF. Further research is needed to elucidate the exact mechanisms that underlie this association.

Striatin plays a major role in angiotensin II-induced cardiomyocyte and cardiac hypertrophy in mice in vivo

The three striatins (STRN, STRN3, STRN4) form the core of STRiatin-Interacting Phosphatase and Kinase (STRIPAK) complexes. These place protein phosphatase 2A (PP2A) in proximity to protein kinases thereby restraining kinase activity and regulating key cellular processes. Our aim was to establish if striatins play a significant role in cardiac remodelling associated with cardiac hypertrophy and heart failure. All striatins were expressed in control human hearts, with up-regulation of STRN and STRN3 in failing hearts. We used mice with global heterozygote gene deletion to assess the roles of STRN and STRN3 in cardiac remodelling induced by angiotensin II (AngII; 7 days). Using echocardiography, we detected no differences in baseline cardiac function or dimensions in STRN+/- or STRN3+/- male mice (8 weeks) compared with wild-type littermates. Heterozygous gene deletion did not affect cardiac function in mice treated with AngII, but the increase in left ventricle mass induced by AngII was inhibited in STRN+/- (but not STRN3+/-) mice. Histological staining indicated that cardiomyocyte hypertrophy was inhibited. To assess the role of STRN in cardiomyocytes, we converted the STRN knockout line for inducible cardiomyocyte-specific gene deletion. There was no effect of cardiomyocyte STRN knockout on cardiac function or dimensions, but the increase in left ventricle mass induced by AngII was inhibited. This resulted from inhibition of cardiomyocyte hypertrophy and cardiac fibrosis. The data indicate that cardiomyocyte striatin is required for early remodelling of the heart by AngII and identify the striatin-based STRIPAK system as a signalling paradigm in the development of pathological cardiac hypertrophy.

Knockdown of SCN5A alters metabolic-associated genes and aggravates hypertrophy in the cardiomyoblast

SCN5A mutations have been reported to cause various cardiomyopathies in humans. Most of the SCN5A mutations causes loss of function and thereby, alters the overall cellular function. Therefore, to understand the loss of SCN5A function in cardiomyocytes, we have knocked down the SCN5A gene (SCN5A-KD) in H9c2 cells and explored the cell phenotype and molecular behaviors in the presence and absence of isoproterenol (ISO), an adrenergic receptor agonist that induces cardiac hypertrophy. Expression of several genes related to hypertrophy, inflammation, fibrosis, and energy metabolism pathways were evaluated. It was found that the mRNA expression of hypertrophy-related gene, brain (B-type) natriuretic peptide (BNP) was significantly increased in SCN5A-KD cells as compared to 'control' H9c2 cells. There was a further increase in the mRNA expressions of BNP and βMHC in SCN5A-KD cells after ISO treatment compared to their respective controls. Pro-inflammatory cytokine, tumor necrosis factor-alpha expression was significantly increased in 'SCN5A-KD' H9c2 cells. Further, metabolism-related genes like glucose transporter type 4, cluster of differentiation 36, peroxisome proliferator-activated receptor alpha, and peroxisome proliferator-activated receptor-gamma were significantly elevated in the SCN5A-KD cells as compared to the control cells. Upregulation of these metabolic genes is associated with increased ATP production. The study revealed that SCN5A knock-down causes alteration of gene expression related to cardiac hypertrophy, inflammation, and energy metabolism pathways, which may promote cardiac remodelling and cardiomyopathy.

Patchouli Alcohol Protects the Heart against Diabetes-Related Cardiomyopathy through the JAK2/STAT3 Signaling Pathway

Diabetic cardiomyopathy (DCM) represents a common pathological state brought about by diabetes mellitus (DM). Patchouli alcohol (PatA) is known for its diverse advantageous effects, notably its anti-inflammatory properties and protective role against metabolic disorders. Despite this, the influence of PatA on DCM remains relatively unexplored. To explore the effect of PatA on diabetes-induced cardiac injury and dysfunction in mice, streptozotocin (STZ) was used to mimic type 1 diabetes in mice. Serological markers and echocardiography show that PatA treatment protects the heart against cardiomyopathy by controlling myocardial fibrosis but not by reducing hyperglycemia in diabetic mice. Discovery Studio 2017 software was used to perform reverse target screening of PatA, and we found that JAK2 may be a potential target of PatA. RNA-seq analysis of heart tissues revealed that PatA activity in the myocardium was primarily associated with the inflammatory fibrosis through the Janus tyrosine kinase 2 (JAK2)/signal transducer and activator of the transcription 3 (STAT3) pathway. In vitro, we also found that PatA alleviates high glucose (HG) + palmitic acid (PA)-induced fibrotic and inflammatory responses via inhibiting the JAK2/STAT3 signaling pathway in H9C2 cells. Our findings illustrate that PatA mitigates the effects of HG + PA- or STZ-induced cardiomyopathy by acting on the JAK2/STAT3 signaling pathway. These insights indicate that PatA could potentially serve as a therapeutic agent for DCM treatment.

Proteomics couples electrical remodelling to inflammation in a murine model of heart failure with sinus node dysfunction

AIMS

In patients with heart failure (HF), concomitant sinus node dysfunction (SND) is an important predictor of mortality, yet its molecular underpinnings are poorly understood. Using proteomics, this study aimed to dissect the protein and phosphorylation remodelling within the sinus node in an animal model of HF with concurrent SND.

METHODS AND RESULTS

We acquired deep sinus node proteomes and phosphoproteomes in mice with heart failure and SND and report extensive remodelling. Intersecting the measured (phospho)proteome changes with human genomics pharmacovigilance data, highlighted downregulated proteins involved in electrical activity such as the pacemaker ion channel, Hcn4. We confirmed the importance of ion channel downregulation for sinus node physiology using computer modelling. Guided by the proteomics data, we hypothesized that an inflammatory response may drive the electrophysiological remodeling underlying SND in heart failure. In support of this, experimentally induced inflammation downregulated Hcn4 and slowed pacemaking in the isolated sinus node. From the proteomics data we identified proinflammatory cytokine-like protein galectin-3 as a potential target to mitigate the effect. Indeed, in vivo suppression of galectin-3 in the animal model of heart failure prevented SND.

CONCLUSION

Collectively, we outline the protein and phosphorylation remodeling of SND in heart failure, we highlight a role for inflammation in electrophysiological remodelling of the sinus node, and we present galectin-3 signalling as a target to ameliorate SND in heart failure.

Synergistic Effects of Weight Loss and Catheter Ablation: Can microRNAs Serve as Predictive Biomarkers for the Prevention of Atrial Fibrillation Recurrence?

In atrial fibrillation (AF), multifactorial pathologic atrial alterations are manifested by structural and electrophysiological changes known as atrial remodeling. AF frequently develops in the context of underlying cardiac abnormalities. A critical mechanistic role played by atrial stretch is played by abnormal substrates in a number of conditions that predispose to AF, including obesity, heart failure, hypertension, and sleep apnea. The significant role of overweight and obesity in the development of AF is known; however, the differential effect of overweight, obesity, cardiovascular comorbidities, lifestyle, and other modifiable risk factors on the occurrence and recurrence of AF remains to be determined. Reverse remodeling of the atrial substrate and subsequent reduction in the AF burden by conversion into a typical sinus rhythm has been associated with weight loss through lifestyle changes or surgery. This makes it an essential pillar in the management of AF in obese patients. According to recently published research, microRNAs (miRs) may function as post-transcriptional regulators of genes involved in atrial remodeling, potentially contributing to the pathophysiology of AF. The focus of this review is on their modulation by both weight loss and catheter ablation interventions to counteract atrial remodeling in AF. Our analysis outlines the experimental and clinical evidence supporting the synergistic effects of weight loss and catheter ablation (CA) in reversing atrial electrical and structural remodeling in AF onset and in recurrent post-ablation AF by attenuating pro-thrombotic, pro-inflammatory, pro-fibrotic, arrhythmogenic, and male-sex-associated hypertrophic remodeling pathways. Furthermore, we discuss the promising role of miRs with prognostic potential as predictive biomarkers in guiding approaches to AF recurrence prevention.

Correlations of sST2 and Gal-3 with Cardiothoracic Ratio in Patients with Chronic Kidney Disease

Chronic kidney disease (CKD) frequently correlates with cardiovascular complications. Soluble suppression of tumorigenicity 2 (sST2) and Galectin-3 (Gal-3) are emerging as cardiac markers with potential relevance in cardiovascular risk prediction. The cardiothoracic ratio (CTR), a metric easily obtainable from chest radiographs, has traditionally been used to assess cardiac size and the potential for cardiomegaly. Understanding the correlation between these cardiac markers and the cardiothoracic ratio (CTR) could provide valuable insights into the cardiovascular prognosis of CKD patients. This study aimed to explore the relationship between sST2, Gal-3, and the CTR in individuals with CKD. Plasma concentrations of sST2 and Gal-3 were assessed in a cohort of 123 CKD patients by enzyme-linked immunosorbent assay (ELISA). On a posterior-to-anterior chest X-ray view, the CTR was determined by comparing the widths of the heart to that of the thorax. The mean concentration of sST2 in the study participants ranged from 775.4 to 4475.6 pg/mL, and the mean concentration of Gal-3 ranged from 4.7 to 9796.0 ng/mL. Significant positive correlations were observed between sST2 and the CTR (r = 0.291, p < 0.001) and between Gal-3 and the CTR (r = 0.230, p < 0.01). Our findings indicate that elevated levels of sST2 and Gal-3 are associated with an increased CTR in CKD patients. This relationship may enable better cardiovascular risk evaluation for CKD patients. Further studies are warranted to explore the clinical implications of these associations.

Angiotensin AT2 receptors reduce inflammation and fibrosis in cardiovascular remodeling

The angiotensin AT2 receptor (AT2R), an important member of the "protective arm" of the renin-angiotensin system (RAS), has been recently defined as a therapeutic target in different pathological conditions. The AT2R activates complex signalling pathways linked to cellular proliferation, differentiation, anti-inflammation, antifibrosis, and induction or inhibition of apoptosis. The anti-inflammatory effect of AT2R activation is commonly associated with reduced fibrosis in different models. Current discoveries demonstrated a direct impact of AT2Rs on the regulation of cytokines, transforming growth factor beta1 (TGF-beta1), matrix metalloproteases (MMPs), and synthesis of the extracellular matrix components. This review article summarizes current knowledge on the AT2R in regard to immunity, inflammation and fibrosis in the heart and blood vessels. In particular, the differential influence of the AT2R on cardiovascular remodeling in preclinical models of myocardial infarction, heart failure and aneurysm formation are discussed. Overall, these studies demonstrate that AT2R stimulation represents a promising therapeutic approach to counteract myocardial and aortic damage in cardiovascular diseases.

The PD-1-PD-L1 pathway maintains an immunosuppressive environment essential for neonatal heart regeneration

The adult mouse heart responds to injury by scarring with consequent loss of contractile function, whereas the neonatal heart possesses the ability to regenerate. Activation of the immune system is among the first events upon tissue injury. It has been shown that immune response kinetics differ between regeneration and pathological remodeling, yet the underlying mechanisms of the distinct immune reactions during tissue healing remain unclear. Here we show that the immunomodulatory PD-1-PD-L1 pathway is highly active in regenerative neonatal hearts but rapidly silenced later in life. Deletion of the PD-1 receptor or inactivation of its ligand PD-L1 prevented regeneration of neonatal hearts after injury. Disruption of the pathway during neonatal cardiac injury led to increased inflammation and aberrant T cell activation, which ultimately impaired cardiac regeneration. Our findings reveal an immunomodulatory and cardioprotective role for the PD-1-PD-L1 pathway in heart regeneration and offer potential avenues for the control of adult tissue regeneration.

Myocardial fibrosis in right heart dysfunction

Cardiac fibrosis, associated with right heart dysfunction, results in significant morbidity and mortality. Stimulated by various cellular and humoral stimuli, cardiac fibroblasts, macrophages, CD4+ and CD8+ T cells, mast and endothelial cells promote fibrogenesis directly and indirectly by synthesizing numerous profibrotic factors. Several systems, including the transforming growth factor-beta and the renin-angiotensin system, produce type I and III collagen, fibronectin and α-smooth muscle actin, thus modifying the extracellular matrix. Although magnetic resonance imaging with gadolinium enhancement remains the gold standard, the use of circulating biomarkers represents an inexpensive and attractive means to facilitate detection and monitor cardiovascular fibrosis. This review explores the use of protein and nucleic acid (miRNAs) markers to better understand underlying pathophysiology as well as their role in the development of therapeutics to inhibit and potentially reverse cardiac fibrosis.

Galectin-3 is involved in inflammation and fibrosis in arteriogenic erectile dysfunction via the TLR4/MyD88/NF-κB pathway

Galectin-3 (Gal-3) is a multifunctional protein that has been linked to fibrosis and inflammation in the cardiovascular system. In this study, we examined the impact of Gal-3 on inflammation and fibrosis in patients with arteriogenic erectile dysfunction (A-ED) and the underlying mechanisms involved. To induce arterial injury, we utilized cuffs on the periaqueductal common iliac arteries of Sprague‒Dawley (SD) rats and administered a high-fat diet to co-induce local atherosclerosis. Our results showed that we successfully developed a novel A-ED model that was validated based on histological evidence. In vivo, the vascular lumen of rats subjected to a high-fat diet and cuff placement exhibited significant narrowing, accompanied by the upregulation of Gal-3, Toll-like receptor 4 (TLR4), and myeloid differentiation primary response protein 88 (MyD88) expression in the penile cavernosa. This led to the activation of nuclear factor kappa B 65 (NF-κB-p65), resulting in reduced intracavernosal pressure, endothelial nitric oxide synthase expression, and smooth muscle content, promoting inflammation and fibrosis. However, treatment with Gal-3 inhibitor-modified citrus pectin (MCP) significantly normalized those effects. In vitro, knocking down Gal-3 led to a significant reduction in TLR4, MyD88, and NF-κB-p65 expression in corpus cavernosum smooth muscle cells (CCSMCs), decreasing inflammation levels. In conclusion, inhibiting Gal-3 may improve A-ED by reducing inflammation, endothelial injury, and fibrosis in the penile corpus cavernosum through the TLR4/MyD88/NF-κB pathway. These findings highlight the potential therapeutic target of Gal-3 in A-ED.

Anti-Inflammation and Anti-Oxidation: The Key to Unlocking the Cardiovascular Potential of SGLT2 Inhibitors and GLP1 Receptor Agonists

Type 2 diabetes mellitus (T2DM) is a prevalent and complex metabolic disorder associated with various complications, including cardiovascular diseases. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP1-RA) have emerged as novel therapeutic agents for T2DM, primarily aiming to reduce blood glucose levels. However, recent investigations have unveiled their multifaceted effects, extending beyond their glucose-lowering effect. SGLT2i operate by inhibiting the SGLT2 receptor in the kidneys, facilitating the excretion of glucose through urine, leading to reduced blood glucose levels, while GLP1-RA mimic the action of the GLP1 hormone, stimulating glucose-dependent insulin secretion from pancreatic islets. Both SGLT2i and GLP1-RA have shown remarkable benefits in reducing major cardiovascular events in patients with and without T2DM. This comprehensive review explores the expanding horizons of SGLT2i and GLP1-RA in improving cardiovascular health. It delves into the latest research, highlighting the effects of these drugs on heart physiology and metabolism. By elucidating their diverse mechanisms of action and emerging evidence, this review aims to recapitulate the potential of SGLT2i and GLP1-RA as therapeutic options for cardiovascular health beyond their traditional role in managing T2DM.

Blockade of Inflammatory Markers Attenuates Cardiac Remodeling and Fibrosis in Rats with Supravalvular Aortic Stenosis

Since cardiac inflammation has been considered an important mechanism involved in heart failure, an anti-inflammatory treatment could control cardiac inflammation and mitigate the worsening of cardiac remodeling. This study evaluated the effects of dexamethasone (DEX) and ramipril treatment on inflammation and cardiac fibrosis in an experimental model of heart failure induced by supravalvular aortic stenosis. Wistar rats (21d) were submitted to an aortic stenosis (AS) protocol. After 21 weeks, an echocardiogram and a maximal exercise test were performed, and after 24 weeks, rats were treated with DEX, ramipril or saline for 14d. The left ventricle (LV) was removed for histological and inflammatory marker analyses. The AS group showed exercise intolerance (-32% vs. Sham), higher relative wall thickness (+63%), collagen deposition and capillary rarefaction, followed by cardiac disfunction. Both treatments were effective in reducing cardiac inflammation, but only DEX attenuated the increased relative wall thickness (-17%) and only ramipril reduced LV fibrosis. In conclusion, both DEX and ramipril decreased cardiac inflammatory markers, which probably contributed to the reduced cardiac fibrosis and relative wall thickness; however, treated AS rats did not show any improvement in cardiac function. Despite the complex pharmacological treatment of heart failure, treatment with an anti-inflammatory could delay the patient's poor prognosis.

SLIT3-mediated fibroblast signaling: a promising target for antifibrotic therapies

The SLIT family (SLIT1-3) of highly conserved glycoproteins was originally identified as ligands for the Roundabout (ROBO) family of single-pass transmembrane receptors, serving to provide repulsive axon guidance cues in the nervous system. Intriguingly, studies involving SLIT3 mutant mice suggest that SLIT3 might have crucial biological functions outside the neural context. Although these mutant mice display no noticeable neurological abnormalities, they present pronounced connective tissue defects, including congenital central diaphragmatic hernia, membranous ventricular septal defect, and osteopenia. We recently hypothesized that the phenotype observed in SLIT3-deficient mice may be tied to abnormalities in fibrillar collagen-rich connective tissue. Further research by our group indicates that both SLIT3 and its primary receptor, ROBO1, are expressed in fibrillar collagen-producing cells across various nonneural tissues. Global and constitutive SLIT3 deficiency not only reduces the synthesis and content of fibrillar collagen in various organs but also alleviates pressure overload-induced fibrosis in both the left and right ventricles. This review delves into the known phenotypes of SLIT3 mutants and the debated role of SLIT3 in vasculature and bone. Present evidence hints at SLIT3 acting as an autocrine regulator of fibrillar collagen synthesis, suggesting it as a potential antifibrotic treatment. However, the precise pathway and mechanisms through which SLIT3 regulates fibrillar collagen synthesis remain uncertain, presenting an intriguing avenue for future research.

Extracellular Matrix Protein-1 as a Mediator of Inflammation-Induced Fibrosis After Myocardial Infarction

Irreversible fibrosis is a hallmark of myocardial infarction (MI) and heart failure. Extracellular matrix protein-1 (ECM-1) is up-regulated in these hearts, localized to fibrotic, inflammatory, and perivascular areas. ECM-1 originates predominantly from fibroblasts, macrophages, and pericytes/vascular cells in uninjured human and mouse hearts, and from M1 and M2 macrophages and myofibroblasts after MI. ECM-1 stimulates fibroblast-to-myofibroblast transition, up-regulates key fibrotic and inflammatory pathways, and inhibits cardiac fibroblast migration. ECM-1 binds HuCFb cell surface receptor LRP1, and LRP1 inhibition blocks ECM-1 from stimulating fibroblast-to-myofibroblast transition, confirming a novel ECM-1-LRP1 fibrotic signaling axis. ECM-1 may represent a novel mechanism facilitating inflammation-fibrosis crosstalk.

Effect of aqueous extract of Indigofera tinctoria (Linn) on aging-induced inflammation and its associated left ventricular hypertrophy and fibrosis in the rat

The aim of the present study is to investigate the ameliorative potential of the aqueous extract of Indigofera tinctoria (IT) in aging-induced inflammation and its associated cardiac hypertrophy and fibrosis. Young (3-month-old) and aged (24-26-month-old) male Wistar albino rats were grouped into young control, aged control, aged + IT, and young + IT. The animals in the supplementary groups received 200 mg/kg BWT of aqueous extract of IT orally once a day for 21 days. Aged animals showed prolonged QT interval and increased weight and volume of the heart with a thickening ventricular wall. Infiltration of leukocytes and increased cardiomyocyte diameter and decreased numerical density along with cardiomyocyte apoptosis and increased collagen accumulation were also seen in aged myocardium when compared to the young. The expression profile of various pro-inflammatory cytokines such as IL-6, IL-1β, TNF-α, NFκB, and iNOS was increased with a concomitant reduction in IL-10 expression in the aged compared to the young. In addition, a marked increase in ROS generation, TGF-β, and α-SMA levels is evident in the aged myocardium. These pathological changes were greatly reversed in aged animals supplemented with IT. Furthermore, the aged + IT group showed repression of pro-inflammatory markers with a subsequent increase in IL-10 expression. Contrarily, no marked changes were observed between young and young + IT groups. Taken together, it is concluded that the aqueous extract of Indigofera tinctoria suppresses cardiac fibrosis and hypertrophy by repressing the inflammation and its associated activation of TGFβ and myofibroblast conversion.

Evaluation of left ventricular function of pregnant women with autoimmune diseases using speckle tracking echocardiography

Pregnancy can cause fluctuations in autoimmune diseases (AD) women, which may aggravate the cardiac damage. Maternal heart function is very important for maternal and fetal health. Therefore, early and accurate evaluation of the heart function of AD pregnant women is necessary. This study was aimed to evaluate the left ventricular (LV) function of AD pregnant women using two-dimensional speckle tracking echocardiography (2DSTE). A total of 96 subjects, including 26 non-pregnant AD patients (AD group), 33 AD pregnant women (AD-P group), and 37 healthy pregnant women (H-P group) were conducted. Baseline clinical and conventional echocardiography characteristics of all the subjects were collected. The 2DSTE was performed to acquire layer-specific strain parameters of LV. Compared with H-P group, AD-P group showed no significant differences in GLSmid and GLSepi. However, the GLSendo (24.10 [22.30 to 25.40] vs. 21.70 [19.05 to 25.15], P = 0.023) and ΔGLS (5.50 [4.80 to 6.00] vs. 4.90 [4.20 to 5.80], P = 0.017) were decreased, while the PSD (27 [23 to 32] vs. 32 [24 to 44], P = 0.014) was increased. At the segmental level, there was no significant difference in apex LSmid and LSepi between the two groups, while the AD-P group showed transmural dysfunction in basal and middle segments, and the LSendo in apex segments (32.84 [28.34 to 34.25] vs. 27.97 [21.87 to 33.61], P = 0.021) were significantly decreased. Compared with AD group, AD-P group showed no significant difference in ΔGLS, PSD, and GLS parameters of three layers. For the segmental level, there were no significant differences in the LSepi of the apex segment and the LS in three layers of the basal and middle segments between the two groups, while LSendo (32.69 [29.13 to 35.53] vs. 27.97 [21.87 to 33.60], P = 0.017) and LSmid (24.70 [22.24 to 27.78] vs. 21.32 [16.91 to 26.11], P = 0.023) in apex segments were significantly lower in AD-P group. The anti-SSA/Ro antibody were positive independently correlated with PSD. In conclusion, layer-specific strain parameters and PSD by 2DSTE provide an accurate and reproducible measurement of myocardial function. There are subclinical LV myocardial dysfunction in AD pregnant women. Besides, the positive of anti-SSA/Ro antibody maybe associated with LV myocardial dysfunction.

Mineralocorticoid receptor antagonists in cardiovascular translational biology

This review examines the role of mineralocorticoid receptor antagonists (MRAs) in cardiovascular biology and the molecular mechanisms involved in mineralocorticoid receptor antagonism. The data discussed suggest that MRAs can play an important role in decreasing the impact of inflammation and fibrosis on cardiorenal outcomes. Evidence derived from major randomized clinical trials demonstrates that steroidal MRAs reduce mortality in patients with heart failure and reduced ejection fraction. Initial positive findings observed in patients with chronic kidney disease and type 2 diabetes (T2D) indicate the possible mechanisms of action of nonsteroidal MRAs, and the clinical benefits for patients with cardiorenal disease and T2D. This article supports the application of basic science concepts to expand our understanding of the molecular mechanisms of action involved in pathophysiology. This approach encourages the development of treatment options before diseases clinically manifest. Video Abstract: http://links.lww.com/CAEN/A42.

Novel AT2R agonist, β-Pro7Ang III, is cardio- and vaso-protective in diabetic spontaneously hypertensive rats

Stimulation of the angiotensin II type 2 receptor (AT2R) evokes protective effects in various cardiovascular diseases. Thus, this study aimed to investigate the effects of AT2R stimulation, with or without AT1R blockade, in a model of hypertension with concomitant type 1 diabetes mellitus (T1DM). Spontaneously hypertensive rats (SHRs) were given either citrate or a single dose of streptozotocin (STZ; 55 mg/kg, i.p.) to induce diabetes. After 4 weeks of diabetes, animals were administered either a vehicle (saline), AT2R agonist, β-Pro7Ang III (0.1 mg/kg/day via osmotic mini-pump), AT1R blocker, candesartan (2 mg/kg/day via drinking water), or a combination of both for a further 8 weeks. β-Pro7Ang III treatment had no effect on blood pressure, but attenuated the significant increase in cardiac interstitial collagen and protein expression of fibrotic and inflammatory markers, and superoxide levels that was evident in diabetic SHRs. These effects were not observed with candesartan, despite its blood pressure lowering effects. Although β-Pro7Ang III had no effect on aortic fibrosis, it significantly attenuated MCP-1 protein expression and superoxide levels when compared to both the non-diabetic and diabetic SHRs, to a similar extent as candesartan. In both the heart and vasculature, the effects of β-Pro7Ang III in combination with candesartan were similar to those of β-Pro7Ang III alone, and superior to candesartan alone. It was concluded that in hypertension with concomitant diabetes, AT2R stimulation with a novel ligand alone, or in combination with AT1R blockade, improved the cardiac and vascular structural changes that were strongly associated with inflammation and oxidative stress, independent of blood pressure regulation.

Protocatechuic acid prevents isoproterenol-induced heart failure in mice by downregulating kynurenine-3-monooxygenase

Protocatechuic acid (3,4-dihydroxybenzoic acid) prevents oxidative stress, inflammation and cardiac hypertrophy. This study aimed to investigate the therapeutic effects of protocatechuic acid in an isoproterenol-induced heart failure mouse model and to identify the underlying mechanisms. To establish the heart failure model, C57BL/6NTac mice were given high-dose isoproterenol (80 mg/kg body weight) for 14 days. Echocardiography revealed that protocatechuic acid reversed the isoproterenol-induced downregulation of fractional shortening and ejection fraction. Protocatechuic acid attenuated cardiac hypertrophy as evidenced by the decreased heart-weight-to-body-weight ratio and the expression of Nppb. RNA sequencing analysis identified kynurenine-3-monooxygenase (Kmo) as a potential target of protocatechuic acid. Protocatechuic acid treatment or transfection with short-interfering RNA against Kmo ameliorated transforming growth factor β1-induced upregulation of Kmo, Col1a1, Col1a2 and Fn1 in vivo or in neonatal rat cardiac fibroblasts. Kmo knockdown attenuated the isoproterenol-induced increase in cardiomyocyte size, as well as Nppb and Col1a1 expression in H9c2 cells or primary neonatal rat cardiomyocytes. Moreover, protocatechuic acid attenuated Kmo overexpression-induced increases in Nppb mRNA levels. Protocatechuic acid or Kmo knockdown decreased isoproterenol-induced ROS generation in vivo and in vitro. Thus, protocatechuic acid prevents heart failure by downregulating Kmo. Therefore, protocatechuic acid and Kmo constitute a potential novel therapeutic agent and target, respectively, against heart failure.

Arrhythmic Mitral Valve Prolapse With Only Mild or Moderate Mitral Regurgitation: Characterization of Myocardial Substrate

BACKGROUND

Sustained ventricular tachycardia and sudden cardiac death due to degenerative mitral valve prolapse (MVP) can occur in the absence of severe mitral regurgitation (MR). A significant percentage of patients with MVP-related sudden death do not have any evidence of replacement fibrosis, suggesting other unrecognized proarrhythmic factors may place these patients at risk.

OBJECTIVES

This study aims to characterize myocardial fibrosis/inflammation and ventricular arrhythmia complexity in patients with MVP and only mild or moderate MR.

METHODS

Prospective observational study of patients with MVP and only mild or moderate MR underwent ventricular arrhythmia characterization and hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI). Coregistered hybrid 18F-fluorodeoxyglucose (18F-FDG)-PET and MRI late gadolinium enhancement images were assessed and categorized. Recruitment occurred in the cardiac electrophysiology clinic.

RESULTS

In 12 patients with degenerative MVP with only mild or moderate MR, of which a majority had complex ventricular ectopy (n = 10, 83%), focal (or focal-on-diffuse) uptake of 18F-FDG (PET-positive) was detected in 83% (n = 10) of patients. Three-quarters of the patients (n = 9, 75%) had FDG uptake that coexisted with areas of late gadolinium enhancement (PET/MRI-positive). Abnormal T1, T2 and extracellular volume (ECV) values were observed in 58% (n = 7), 25% (n = 3), and 16% (n = 2), respectively.

CONCLUSIONS

Most patients with degenerative MVP, ventricular ectopy, and mild or moderate MR show myocardial inflammation that is concordant with myocardial scar. Further study is needed to determine whether these findings contribute to the observation that most MVP-related sudden deaths occur in patients with less than severe MR.

Adenosine signaling as target in cardiovascular pharmacology

Increasing evidence demonstrated the relevance of adenosine system in the onset and development of cardiovascular diseases, such as hypertension, myocardial infarct, ischemia, hypertension, heart failure, and atherosclerosis. In this regard, intense research efforts are being focused on the characterization of the pathophysiological significance of adenosine, acting at its membrane receptors named A1, A2A, A2B, and A3 receptors, in cardiovascular diseases. The present review article provides an integrated and comprehensive overview about current clinical and pre-clinical evidence about the role of adenosine in the pathophysiology of cardiovascular diseases. Particular attention has been focused on current scientific evidence about the pharmacological ligands acting on adenosine pathway as useful tools to manage cardiovascular diseases.

APJ as Promising Therapeutic Target of Peptide Analogues in Myocardial Infarction- and Hypertension-Induced Heart Failure

The widely expressed G protein-coupled apelin receptor (APJ) is activated by two bioactive endogenous peptides, apelin and ELABELA (ELA). The apelin/ELA-APJ-related pathway has been found involved in the regulation of many physiological and pathological cardiovascular processes. Increasing studies are deepening the role of the APJ pathway in limiting hypertension and myocardial ischaemia, thus reducing cardiac fibrosis and adverse tissue remodelling, outlining APJ regulation as a potential therapeutic target for heart failure prevention. However, the low plasma half-life of native apelin and ELABELA isoforms lowered their potential for pharmacological applications. In recent years, many research groups focused their attention on studying how APJ ligand modifications could affect receptor structure and dynamics as well as its downstream signalling. This review summarises the novel insights regarding the role of APJ-related pathways in myocardial infarction and hypertension. Furthermore, recent progress in designing synthetic compounds or analogues of APJ ligands able to fully activate the apelinergic pathway is reported. Determining how to exogenously regulate the APJ activation could help to outline a promising therapy for cardiac diseases.

Cardiovascular Magnetic Resonance in Survivors of Critical Illness: Cardiac Abnormalities Are Associated With Acute Kidney Injury

Background The objective of this study was to investigate cardiac abnormalities in intensive care unit (ICU) survivors of critical illness and to determine whether temporary acute kidney injury (AKI) is associated with more pronounced findings on cardiovascular magnetic resonance. Methods and Results There were 2175 patients treated in the ICU (from 2015 until 2021) due to critical illness who were screened for study eligibility. Post-ICU patients without known cardiac disease were prospectively recruited from March 2021 to May 2022. Participants underwent cardiovascular magnetic resonance including assessment of cardiac function, myocardial edema, late gadolinium enhancement, and mapping including extracellular volume fraction. Student t test, Mann-Whitney U test, and χ2 tests were used. There were 48 ICU survivors (46±15 years of age, 28 men, 29 with AKI and continuous kidney replacement therapy, and 19 without AKI) and 20 healthy controls who were included. ICU survivors had elevated markers of myocardial fibrosis (T1: 995±31 ms versus 957±21 ms, P<0.001; extracellular volume fraction: 24.9±2.5% versus 22.8±1.2%, P<0.001; late gadolinium enhancement: 1% [0%-3%] versus 0% [0%-0%], P<0.001), more frequent focal late gadolinium enhancement lesions (21% versus 0%, P=0.03), and an impaired left ventricular function (eg, ejection fraction: 57±6% versus 60±5%, P=0.03; systolic longitudinal strain: 20.3±3.7% versus 23.1±3.5%, P=0.004) compared with healthy controls. ICU survivors with AKI had higher myocardial T1 (1002±33 ms versus 983±21 ms; P=0.046) and extracellular volume fraction values (25.6±2.6% versus 23.9±1.9%; P=0.02) compared with participants without AKI. Conclusions ICU survivors of critical illness without previously diagnosed cardiac disease had distinct abnormalities on cardiovascular magnetic resonance including signs of myocardial fibrosis and systolic dysfunction. Findings were more abnormal in participants who experienced AKI with necessity of continuous kidney replacement therapy during their ICU stay. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05034588.

Mitigation of Cardiovascular Disease and Toxicity through NRF2 Signalling

Cardiovascular toxicity and diseases are phenomena that have a vastly detrimental impact on morbidity and mortality. The pathophysiology driving the development of these conditions is multifactorial but commonly includes the perturbance of reactive oxygen species (ROS) signalling, iron homeostasis and mitochondrial bioenergetics. The transcription factor nuclear factor erythroid 2 (NFE2)-related factor 2 (NRF2), a master regulator of cytoprotective responses, drives the expression of genes that provide resistance to oxidative, electrophilic and xenobiotic stresses. Recent research has suggested that stimulation of the NRF2 signalling pathway can alleviate cardiotoxicity and hallmarks of cardiovascular disease progression. However, dysregulation of NRF2 dynamic responses can be severely impacted by ageing processes and off-target toxicity from clinical medicines including anthracycline chemotherapeutics, rendering cells of the cardiovascular system susceptible to toxicity and subsequent tissue dysfunction. This review addresses the current understanding of NRF2 mechanisms under homeostatic and cardiovascular pathophysiological conditions within the context of wider implications for this diverse transcription factor.

Immobilizing Interstitial Cardiac Fibrosis

Background

The alterations in the endomysium and perimysium might cause compaction and gradual mechanical compression of cardiomyocytes resulting in their immobilization. This process finally leads to severe stiffening, so that the newly formed frame around individual cardiomyocytes and their clusters hinders normal diastole, and later systole. This phenomenon is referred to as immobilizing interstitial cardiac fibrosis (IICF). Deciphering the molecular and structural elements of myocardial changes is the key to understanding the pathogenetic foundations of heart failure development.

Methods

The study included 69 patients. Group I (n = 32) included patients with IICF; group II (n = 37) was comparison group. We evaluated the clinical picture, anamnesis of the disease, the results of physical examination, laboratory and instrumental examination of patients and autopsy data.

Results

In the anamnesis, patients with IICF were more likely to have diseases than patients in the control group: arrhythmia and impaired conductivity (88% vs. 19%, odds ratio (OR): 30.0; 95% confidence interval (CI): 7.918 - 113.7, P < 0.001), systemic connective tissue diseases (78% vs. 5%, OR: 62.5; 95% CI: 11.9 - 326.5, P < 0.001), viral infections (including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) (53% vs. 19%, OR: 4.86; 95% CI: 1.66 - 14.25, P = 0.003), type 2 diabetes mellitus (47% vs. 8%, OR: 10.0; 95% CI: 2.54 - 39.34, P < 0.001), radiation therapy for mediastinal lymphoma and other oncological diseases (19% vs. 0%, P = 0.008), focal infections (sinusitis, osteomyelitis, periodontitis, nephritis, cystitis, pyelonephritis, pleurisy, etc.) within 12 months (31% vs. 11%, P = 0.069), chronic kidney disease (25% vs. 8%, P = 0.097), and tuberculosis (9% vs. 0%, P = 0.095). We have identified a statistically significant difference between the groups: the volume of the fibrosis zone (17.5±9.2% vs. 4.9±2.3%, P = 0.001), the expression of type I collagen (5,182 ± 1,301 vs. 2,189 ± 754 in 1 mm², P = 0.0001), type III collagen (7,562 ± 1,405 vs. 2,320 ± 541 in 1 mm², P = 0.0001), matrix metalloproteinase (MMP)-2 (12,850 ± 6,200 vs. 9,501 ± 7,145 in 1 mm², P = 0.005), MMP-9 (15,745 ± 5,695 vs. 6,920 ± 3,125 in 1 mm², P = 0.0001), connexin-43 (25,689 ± 14,871 vs. 37,523 ± 12,561 in 1 mm², P = 0.001), fibronectin (3,448 ± 720 vs. 1,544 ± 610 in 1 mm², P = 0.0001), and transforming growth factor β (TGF-β) (5,121 ± 1,243 vs. 2,531 ± 1,489 in 1 mm², P = 0.001).

Conclusion

IICF is a separate pathological condition and one of the main causes of chronic heart failure. It is induced by changes in the myocardial connective tissue that prevent normal functioning of the myocardium.

Molecular mechanisms and targets of right ventricular fibrosis in pulmonary hypertension

Right ventricular fibrosis is a stress response, predominantly mediated by cardiac fibroblasts. This cell population is sensitive to increased levels of pro-inflammatory cytokines, pro-fibrotic growth factors and mechanical stimulation. Activation of fibroblasts results in the induction of various molecular signaling pathways, most notably the mitogen-activated protein kinase cassettes, leading to increased synthesis and remodeling of the extracellular matrix. While fibrosis confers structural protection in response to damage induced by ischemia or (pressure and volume) overload, it simultaneously contributes to increased myocardial stiffness and right ventricular dysfunction. Here, we review state-of-the-art knowledge of the development of right ventricular fibrosis in response to pressure overload and provide an overview of all published preclinical and clinical studies in which right ventricular fibrosis was targeted to improve cardiac function.

The Viral G-Protein-Coupled Receptor Homologs M33 and US28 Promote Cardiac Dysfunction during Murine Cytomegalovirus Infection

Human cytomegalovirus (HCMV) is a ubiquitous pathogen that infects the majority of the world population and causes lifelong latent infection. HCMV has been shown to exacerbate cardiovascular diseases, including myocarditis, vascular sclerosis, and transplant vasculopathy. Recently, we have shown that murine CMV (MCMV) recapitulates the cardiovascular dysfunction observed in patients with HCMV-induced myocarditis. To understand the viral mechanisms involved in CMV-induced heart dysfunction, we further characterized cardiac function in response to MCMV and examined virally encoded G-protein-coupled receptor homologs (vGPCRs) US28 and M33 as potential factors that promote infection in the heart. We hypothesized that the CMV-encoded vGPCRs could exacerbate cardiovascular damage and dysfunction. Three viruses were used to evaluate the role of vGPCRs in cardiac dysfunction: wild-type MCMV, a M33-deficient virus (∆M33), and a virus with the M33 open reading frame (ORF) replaced with US28, an HCMV vGPCR (i.e., US28+). Our in vivo studies revealed that M33 plays a role in promoting cardiac dysfunction by increasing viral load and heart rate during acute infection. During latency, ΔM33-infected mice demonstrated reduced calcification, altered cellular gene expression, and less cardiac hypertrophy compared with wild-type MCMV-infected mice. Ex vivo viral reactivation from hearts was less efficient in ΔM33-infected animals. HCMV protein US28 expression restored the ability of the M33-deficient virus to reactivate from the heart. US28+ MCMV infection caused damage to the heart comparable with wild-type MCMV infection, suggesting that the US28 protein is sufficient to complement the function of M33 in the heart. Altogether, these data suggest a role for vGPCRs in viral pathogenesis in the heart and thus suggest that vGPCRs promote long-term cardiac damage and dysfunction.

Left ventricular function by strain in uncomplicated malaria: a prospective study from the Brazilian Amazon

We hypothesized that adults with uncomplicated malaria have lower left ventricular contractile function compared to the general population and that this improves after antimalarial treatment. We examined uncomplicated malaria and the general population from the Western part of the Brazilian Amazon Basin. All persons underwent an echocardiographic examination and peripheral blood smears. Left ventricular function was assessed by speckle tracking analysis of global longitudinal strain (GLS). Logistic regression models were used to assess the association between malaria status (yes/no) and GLS and improvement in GLS by follow-up was assessed using a paired T-test. We enrolled 99 adults with uncomplicated malaria (mean age 40 years, 46% female) of whom 75 had Plasmodium vivax, 22 Plasmodium falciparum and two had both species [median 1595 (528 to 6585) parasites/mm³]. Seventy adults completed a follow-up examination after standard malaria treatment (median 31 days). We examined 486 from the general population (mean age 41 years, 63% female). In persons with malaria at baseline, GLS was lower compared to the general population (18.7% vs. 19.4%, P = 0.002) and GLS improved at follow-up (19.2%, P = 0.032). In multivariable models adjusted for clinical, socioeconomic and echocardiographic confounders, baseline GLS remained significantly associated with malaria status [odds ratio 2.45 (95%CI 1.00 to 7.25), P = 0.023 per 1% increase]. Parasite density was associated with worsening in GLS [+ 16% (+ 0% to + 34%), P = 0.047 per 1 unit increase in GLS]. Adults with uncomplicated malaria had lower GLS compared to the general population and this improved after completed antimalarial treatment. Our results suggest that malaria infection may affect left ventricular contractile function, however, further studies are needed to fully elucidate such a relationship.

Mitochondria-derived damage-associated molecular patterns and inflammation in the ischemic-reperfused heart

Cardiac cell death after myocardial infarction release endogenous structures termed damage-associated molecular patterns (DAMPs) that trigger the innate immune system and initiate a sterile inflammation in the myocardium. Cardiomyocytes are energy demanding cells and 30% of their volume are mitochondria. Mitochondria are evolutionary endosymbionts originating from bacteria containing molecular patterns similar to bacteria, termed mitochondrial DAMPs (mDAMPs). Consequently, mitochondrial debris may be particularly immunogenic and damaging. However, the role of mDAMPs in myocardial infarction is not clarified. Identifying the most harmful mDAMPs and inhibiting their early inflammatory signaling may reduce infarct size and the risk of developing post-infarct heart failure. The focus of this review is the role of mDAMPs in the immediate pro-inflammatory phase after myocardial infarction before arrival of immune cells in the myocardium. We discuss different mDAMPs, their role in physiology and present knowledge regarding their role in the inflammatory response of acute myocardial infarction.

Experimental heart failure models in small animals

Heart failure (HF) is one of the most critical health and economic burdens worldwide, and its prevalence is continuously increasing. HF is a disease that occurs due to a pathological change arising from the function or structure of the heart tissue and usually progresses. Numerous experimental HF models have been created to elucidate the pathophysiological mechanisms that cause HF. An understanding of the pathophysiology of HF is essential for the development of novel efficient therapies. During the past few decades, animal models have provided new insights into the complex pathogenesis of HF. Success in the pathophysiology and treatment of HF has been achieved by using animal models of HF. The development of new in vivo models is critical for evaluating treatments such as gene therapy, mechanical devices, and new surgical approaches. However, each animal model has advantages and limitations, and none of these models is suitable for studying all aspects of HF. Therefore, the researchers have to choose an appropriate experimental model that will fully reflect HF. Despite some limitations, these animal models provided a significant advance in the etiology and pathogenesis of HF. Also, experimental HF models have led to the development of new treatments. In this review, we discussed widely used experimental HF models that continue to provide critical information for HF patients and facilitate the development of new treatment strategies.

Association between proteomic biomarkers and myocardial fibrosis measured by MRI: the multi-ethnic study of atherosclerosis

BACKGROUND

Cardiac magnetic resonance imaging (CMR) determines the extent of interstitial fibrosis, measured by increased extracellular volume (ECV), and replacement fibrosis with late gadolinium myocardial enhancement (LGE). Despite advances in detection, the pathophysiology of subclinical myocardial fibrosis is incompletely understood. Targeted proteomic discovery technologies enable quantification of low abundance circulating proteins to elucidate cardiac fibrosis mechanisms.

METHODS

Using a cross-sectional design, we selected 92 LGE+ cases and 92 LGE- demographically matched controls from the Multi-Ethnic Study of Atherosclerosis. Similarly, we selected 156 cases from the highest ECV quartile and matched with 156 cases from the lowest quartile. The plasma serum proteome was analyzed using proximity extension assays to determine differential regulation of 92 proteins previously implicated with cardiovascular disease. Results were analyzed using volcano plots of statistical significance vs. magnitude of change and Bayesian additive regression tree (BART) models to determine importance.

FINDINGS

After adjusting for false discovery, higher ECV was significantly associated with 17 proteins. Using BART, Plasminogen activator inhibitor 1, Insulin-like growth factor-binding protein 1, and N-terminal pro-B-type natriuretic peptide were associated with higher ECV after accounting for other proteins and traditional cardiovascular risk factors. In contrast, no circulating proteins were associated with replacement fibrosis.

INTERPRETATIONS

Our results suggest unique circulating proteomic signatures associated with interstitial fibrosis emphasizing its systemic influences. With future validation, protein panels may identify patients who may develop interstitial fibrosis with progression to heart failure.

FUNDING

This research was supported by contracts and grants from NHLBI, NCATS and the Inova Heart and Vascular Institute.

Association of Lung Fibrotic Changes and Cardiological Dysfunction with Comorbidities in Long COVID-19 Cohort

Background. Long COVID-19 symptoms appeared in many COVID-19 survivors. However, the prevalence and symptoms associated with long COVID-19 and its comorbidities have not been established. Methods. In total, 312 patients with long COVID-19 from 21 primary care centers were included in the study. At the six-month follow-up, their lung function was assessed by computerized tomography (CT) and spirometry, whereas cardiac function was assessed by elec-trocardiogram (ECG), Holter ECG, echocardiography, 24 h blood pressure monitoring, and a six-minute walk test (6MWT). Results. Of the 312 persons investigated, significantly higher sys-tolic and diastolic blood pressure, left ventricular hypertrophy, and elevated NT-proBNP were revealed in participants with hypertension or type 2 diabetes. Left ventricular diastolic dysfunc-tion was more frequently present in patients with hypertension. The most common registered CT abnormalities were fibrotic changes (83, 36.6%) and mediastinal lymphadenopathy (23, 10.1%). Among the tested biochemical parameters, three associations were found in long COVID-19 patients with hypertension but not diabetes: increased hemoglobin, fibrinogen, and ferritin. Nine patients had persisting IgM antibodies to SARS-CoV-2. Conclusions. We demon-strated a strong association between signs of cardiac dysfunction and lung fibrotic changes with comorbidities in a cohort of long COVID-19 subjects.

A genomic meta-analysis of clinical variables and their association with intrinsic molecular subsets in systemic sclerosis

OBJECTIVES

Four intrinsic molecular subsets (inflammatory, fibroproliferative, limited, normal-like) have previously been identified in SSc and are characterized by unique gene expression signatures and pathways. The intrinsic subsets have been linked to improvement with specific therapies. Here, we investigated associations between baseline demographics and intrinsic molecular subsets in a meta-analysis of published datasets.

METHODS

Publicly available gene expression data from skin biopsies of 311 SSc patients measured by DNA microarray were classified into the intrinsic molecular subsets. RNA-sequencing data from 84 participants from the ASSET trial were used as a validation cohort. Baseline clinical demographics and intrinsic molecular subsets were tested for statistically significant associations.

RESULTS

Males were more likely to be classified in the fibroproliferative subset (P = 0.0046). SSc patients who identified as African American/Black were 2.5 times more likely to be classified as fibroproliferative compared with White/Caucasian patients (P = 0.0378). ASSET participants sera positive for anti-RNA pol I and RNA pol III autoantibodies were enriched in the inflammatory subset (P = 5.8 × 10-5, P = 9.3 × 10-5, respectively), while anti-Scl-70 was enriched in the fibroproliferative subset. Mean modified Rodnan Skin Score (mRSS) was statistically higher in the inflammatory and fibroproliferative subsets compared with normal-like (P = 0.0027). The average disease duration for inflammatory subset was less than fibroproliferative and normal-like intrinsic subsets (P = 8.8 × 10-4).

CONCLUSIONS

We identified multiple statistically significant differences in baseline demographics between the intrinsic subsets that may represent underlying features of disease pathogenesis (e.g. chronological stages of fibrosis) and have implications for treatments that are more likely to work in certain SSc populations.

Cardiac damage in autoimmune diseases: Target organ involvement that cannot be ignored

Autoimmune diseases are diseases that cause damage to the body's own tissues as a result of immune dysfunction, often involving multiple organs and systems. The heart is one of the common target organs of autoimmune diseases. The whole structure of the heart can be affected, causing microcirculatory disorders, arrhythmias, pericardial damage, myocarditis, myocardial fibrosis, and impaired valvular function. However, early clinical manifestations of autoimmune heart damage are often overlooked because they are insidious or have no typical features. The damage is often severe and irreversible when symptoms are apparent, even life-threatening. Therefore, early detection and treatment of heart damage in autoimmune diseases is particularly important. Herein, we review the clinical features and mechanisms of cardiac damage in common rheumatic diseases.

The Novel AT2 Receptor Agonist β-Pro7-AngIII Exerts Cardiac and Renal Anti-Fibrotic and Anti-Inflammatory Effects in High Salt-Fed Mice

A high salt (HS) diet is associated with an increased risk for cardiovascular diseases (CVDs) and fibrosis is a key contributor to the organ dysfunction involved in CVDs. The activation of the renin angiotensin type 2 receptor (AT₂R) has been considered as organ protective in many CVDs. However, there are limited AT₂R-selective agonists available. Our first reported β-substituted angiotensin III peptide, β-Pro⁷-AngIII, showed high selectivity for the AT₂R. In the current study, we examine the potential anti-fibrotic and anti-inflammatory effects of this novel AT₂R-selective peptide on HS-induced organ damage. FVB/N mice fed with a 5% HS diet for 8 weeks developed cardiac and renal fibrosis and inflammation, which were associated with increased TGF-β1 levels in heart, kidney and plasma. Four weeks' treatment (from weeks 5-8) with β-Pro⁷-AngIII inhibited the HS-induced cardiac and renal fibrosis and inflammation. These protective effects were accompanied by reduced local and systemic TGF-β1 as well as reduced cardiac myofibroblast differentiation. Importantly, the anti-fibrotic and anti-inflammatory effects caused by β-Pro⁷-AngIII were attenuated by the AT₂R antagonist PD123319. These results demonstrate, for the first time, the cardio- and reno-protective roles of the AT₂R-selective β-Pro⁷-AngIII, highlighting it as an important therapeutic that can target the AT₂R to treat end-organ damage.

Adverse effects of air pollution-derived fine particulate matter on cardiovascular homeostasis and disease

Air pollution is a rapidly growing major health concern around the world. Atmospheric particulate matter that has a diameter of less than 2.5 µm (PM2.5) refers to an air pollutant composed of particles and chemical compounds that originate from various sources. While epidemiological studies have established the association between PM2.5 exposure and cardiovascular diseases, the precise cellular and molecular mechanisms by which PM2.5 promotes cardiovascular complications are yet to be fully elucidated. In this review, we summarize the various sources of PM2.5, its components, and the concentrations of ambient PM2.5 in various settings. We discuss the experimental findings to date that evaluate the potential adverse effects of PM2.5 on cardiovascular homeostasis and function, and the possible therapeutic options that may alleviate PM2.5-driven cardiovascular damage.

Circulating biomarker correlates of left atrial size and myocardial extracellular volume fraction among persons living with and without HIV

BACKGROUND

Infection with human immunodeficiency virus (HIV) is associated with higher risk for myocardial disease despite modern combination antiretroviral therapy (cART). Factors contributing to this excess risk, however, remain poorly characterized. We aimed to assess cross-sectional relationships between elevations of left atrial volume index (LAVI) and myocardial extracellular volume (ECV) fraction that have been reported in persons living with HIV and levels of circulating biomarkers of inflammation, fibrosis, and myocyte stretch among persons living with and without HIV (PLWH, PLWOH).

METHODS

Participants from three cohorts of PLWH and PLWOH underwent cardiovascular magnetic resonance imaging for measurement of LAVI and ECV. Levels of circulating proteins (IL-6, sCD14, galectin-3, NT-proBNP, GDF-15, TIMP-2, MMP-2, and hsTnI) were measured using immunoassays. Associations were assessed using logistic and linear regression, adjusting for demographics, substance use, and clinical characteristics.

RESULTS

Among 381 participants with and without HIV, median age (IQR) was 55.1 (51.2, 58.4) years, 28% were female, 69% were Black, and 46% were current smokers. Sixty-two percent were PLWH (n = 235), of whom 88% were receiving cART and 72% were virally suppressed. PLWH had higher levels of sCD14 (p = < 0.001), GDF-15 (p = < 0.001), and NT-proBNP (p = 0.03) compared to PLWOH, while levels of other biomarkers did not differ by HIV serostatus, including IL-6 (p = 0.84). Among PLWH, higher sCD14, GDF-15, and NT-proBNP were also associated with lower CD4 + cell count, and higher NT-proBNP was associated with detectable HIV viral load. NT-proBNP was associated with elevated LAVI (OR: 1.79 [95% CI: 1.31, 2.44]; p < 0.001) with no evidence of effect measure modification by HIV serostatus. Other associations between HIV-associated biomarkers and LAVI or ECV were small or imprecise.

CONCLUSIONS

Our findings suggest that elevated levels of sCD14, GDF-15, and NT-proBNP among PLWH compared to PLWOH observed in the current cART era may only minimally reflect HIV-associated elevations in LAVI and ECV. Future studies of excess risk of myocardial disease among contemporary cohorts of PLWH should investigate mechanisms other than those connoted by the studied biomarkers.

Increased inflammatory markers in adult patients born with an atrial septal defect

Patients with atrial septal defect (ASD) have higher mortality and higher risk of atrial fibrillation, heart failure, pneumonia, and stroke than the general population even if the ASD closes spontaneously in childhood. The reason for the long-term complications remains unknown. Since many of the complications can be linked up with alterations in inflammatory response, we speculate that inflammation may contribute to the association between ASD and morbidity and mortality. We investigated inflammatory activity in adults with an ASD compared with controls. We included 126 adults with an unrepaired ASD. A group of healthy controls were recruited as comparison group (n = 23). Serum samples were analyzed for 92 inflammation-related protein biomarkers using a proximity extension assay. A pathway enrichment analysis was performed using Reactome database. Out of 92 biomarkers, 73 were eligible for data analysis. Increased levels of 14 (19%) biomarkers were found in patients with open ASD and 24 (33%) biomarkers in patients with spontaneously closed defects compared with controls (p < 0.05). Multiple inflammatory pathways showed stronger enrichment in both patient groups when compared with controls. In conclusion, inflammatory activity is altered in adult patients with an unrepaired ASD compared with healthy controls. The increased inflammatory burden of patients with an unrepaired ASD may contribute to the development of morbidities.

Intercellular model predicts mechanisms of inflammation-fibrosis coupling after myocardial infarction

After myocardial infarction (MI), cardiac cells work together to regulate wound healing of the infarct. The pathological response to MI yields cardiac remodelling comprising inflammatory and fibrosis phases, and the interplay of cellular dynamics that underlies these phases has not been elucidated. This study developed a computational model to identify cytokine and cellular dynamics post-MI to predict mechanisms driving post-MI inflammation, resolution of inflammation, and scar formation. Additionally, this study evaluated the interdependence between inflammation and fibrosis. Our model bypassed limitations of in vivo approaches in achieving cellular specificity and performing specific perturbations such as global knockouts of chemical factors. The model predicted that inflammation is a graded response to initial infarct size that is amplified by a positive feedback loop between neutrophils and interleukin 1β (IL-1β). Resolution of inflammation was driven by degradation of IL-1β, matrix metalloproteinase 9, and transforming growth factor β (TGF-β), as well as apoptosis of neutrophils. Inflammation regulated TGFβ secretion directly through immune cell recruitment and indirectly through upregulation of macrophage phagocytosis. Lastly, we found that mature collagen deposition was an ultrasensitive switch in response to inflammation, which was amplified primarily by cardiac fibroblast proliferation. These findings describe the relationship between inflammation and fibrosis and highlight how the two responses work together post-MI. This model revealed that post-MI inflammation and fibrosis are dynamically coupled, which provides rationale for designing novel anti-inflammatory, pro-resolving or anti-fibrotic therapies that may improve the response to MI. KEY POINTS: Inflammation and matrix remodelling are two processes involved in wound healing after a heart attack. Cardiac cells work together to facilitate these processes; this is done by secreting cytokines that then regulate the cells themselves or other cells surrounding them. This study developed a computational model of the dynamics of cardiac cells and cytokines to predict mechanisms through which inflammation and matrix remodelling is regulated. We show the roles of various cytokines and signalling motifs in driving inflammation, resolution of inflammation and fibrosis. The novel concept of inflammation-fibrosis coupling, based on the model prediction that inflammation and fibrosis are dynamically coupled, provides rationale for future studies and for designing therapeutics to improve the response after a heart attack.

Evidence of Failed Resolution Mechanisms in Arrhythmogenic Inflammation, Fibrosis and Right Heart Disease

Inflammation is a complex program of active processes characterized by the well-orchestrated succession of an initiation and a resolution phase aiming to promote homeostasis. When the resolution of inflammation fails, the tissue undergoes an unresolved inflammatory status which, if it remains uncontrolled, can lead to chronic inflammatory disorders due to aggravation of structural damages, development of a fibrous area, and loss of function. Various human conditions show a typical unresolved inflammatory profile. Inflammatory diseases include cancer, neurodegenerative disease, asthma, right heart disease, atherosclerosis, myocardial infarction, or atrial fibrillation. New evidence has started to emerge on the role, including pro-resolution involvement of chemical mediators in the acute phase of inflammation. Although flourishing knowledge is available about the role of specialized pro-resolving mediators in neurodegenerative diseases, atherosclerosis, obesity, or hepatic fibrosis, little is known about their efficacy to combat inflammation-associated arrhythmogenic cardiac disorders. It has been shown that resolvins, including RvD1, RvE1, or Mar1, are bioactive mediators of resolution. Resolvins can stop neutrophil activation and infiltration, stimulate monocytes polarization into anti-inflammatory-M2-macrophages, and activate macrophage phagocytosis of inflammation-debris and neutrophils to promote efferocytosis and clearance. This review aims to discuss the paradigm of failed-resolution mechanisms (FRM) potentially promoting arrhythmogenicity in right heart disease-induced inflammatory status.

Galectin-3 as a Marker of Cardiorenal Syndrome in Patients with Chronic Heart Failure

Aim. To assess the effect of renal dysfunction on the galectin-3 level in patients with chronic heart failure (HF) with preserved, intermediate and reduced left ventricular ejection fraction (EF).Material and methods. Along with a clinical examination, 69 patients with HF (NYHA class II-IV) underwent tests for the level of NT-proBNP and galectin-3 in serum using enzyme immunoassay.Results. Study participants were divided into 3 groups: 23 patients with preserved EF (HFpEF), 26 patients with midrange EF (HFmrEF), 20 patients with reduced EF (HFrEF). There was a trend to increase the concentration of galectin-3 with increase in NT-proBNP level. Correlation analysis showed significant feedback (r=−0.41, p<0.05) between galectin-3 and EF only in patients with preserved systolic function. In the same group of HFpEF patients, the maximum serum galectin-3 level was 10.5 [6.5; 14.5] ng/ml. Serum galectin-3 level showed negative correlated with the GFR in patients with CHF (r=−0.513, p<0.05). In patients with HF and glomerular filtration rate (GFR) <60 ml/min/1.73 m2 it was higher than in patients with GFR>60 ml/min/1.72 m2 (9 [5.3; 12.6] ng/mL vs 11.8 [6.2; 15.3] ng/mL, p<0.05). According to the ROC-analysis data, galectin-3 level >10.3 ng/ml indicates a high risk of chronic kidney disease stage 3-4 stage development (sensitivity 60%, specificity 75%) and can be considered as a risk factor for development of cardiorenal syndrome in HF patients.Conclusion. Galectin-3 level in patients with HF is more influenced by the degree of reduction in GFR rather than the left ventricular systolic function impairment.

Loss of talin in cardiac fibroblasts results in augmented ventricular cardiomyocyte hypertrophy in response to pressure overload

Pressure overload of the heart is characterized by concentric hypertrophy and interstitial fibrosis. Cardiac fibroblasts (CFs) in the ventricular wall become activated during injury and synthesize and compact the extracellular matrix, which causes interstitial fibrosis and stiffening of the ventricular heart walls. Talin1 (Tln1) and Talin2 (Tln2) are mechanosensitive proteins that participate in focal adhesion transmission of signals from the extracellular environment to the actin cytoskeleton of CFs. The aim of the present study was to determine whether the removal of Tln1 and Tln2 from CFs would reduce interstitial fibrosis and cardiac hypertrophy. Twelve-week-old male and female Tln2-null (Tln2-/-) and Tln2-null, CF-specific Tln1 knockout (Tln2-/-;Tln1CF-/-) mice were given angiotensin-II (ANG II) (1.5 mg/kg/day) or saline through osmotic pumps for 8 wk. Cardiomyocyte area and measures of heart thickness were increased in the male ANG II-infused Tln2-/-;Tln1CF-/- mice, whereas there was no increase in interstitial fibrosis. Systolic blood pressure was increased in the female Tln2-/-;Tln1CF-/- mice after ANG II infusion compared with the Tln2-/- mice. However, there was no increase in cardiac hypertrophy in the Tln2-/-;Tln1CF-/- mice, which was seen in the Tln2-/- mice. Collectively, these data indicate that in male mice, the absence of Tln1 and Tln2 in CFs leads to cardiomyocyte hypertrophy in response to ANG II, whereas it results in a hypertrophy-resistant phenotype in female mice. These findings have important implications for the role of mechanosensitive proteins in CFs and their impact on cardiomyocyte function in the pathogenesis of hypertension and cardiac hypertrophy.NEW & NOTEWORTHY The role of talins has been previously studied in cardiomyocytes; however, these mechanotransductive proteins that are members of the focal adhesion complex have not been examined in cardiac fibroblasts previously. We hypothesized that loss of talins in cardiac fibroblasts would reduce interstitial fibrosis in the heart with a pressure overload model. However, we found that although loss of talins did not alter fibrosis, it did result in cardiomyocyte and ventricular hypertrophy.

Relation between lymphocyte to monocyte ratio and survival in patients with hypertrophic cardiomyopathy: a retrospective cohort study

Background

The lymphocyte-to-monocyte ratio (LMR) has been proposed as a novel prognostic factor in malignancies and cardiovascular diseases. Our study aimed to ascertain whether LMR is a useful biomarker in discriminating the hypertrophic cardiomyopathy (HCM) patients at higher risk of all-cause mortality.

Methods

This retrospective study consisted of 354 adult HCM patients. Cox's proportional hazards regression models were used to analyze the association between LMR and all-cause mortality. Smooth curve fitting was conducted to explore the linear relationship between LMR and all-cause mortality.

Results

During the follow-up, 44 patients reached the study endpoint. The all-cause mortality rate was 7.3 per 100 person-years in the first tertile and decreased across the three tertiles of LMR. With the first tertile as reference, adjusted hazard ratios (HR) for all-cause mortality were 0.43 for the second tertile (95% CI [0.20-0.91], p = 0.027) and 0.39 for the third tertile (95% CI [0.17-0.90], p = 0.028), respectively. Smooth curve fitting exhibited a nonlinear relationship between LMR values and all-cause mortality. For LMR < 6.5, per SD increase resulted in a significantly decreased risk of all-cause mortality by 62% (HR: 0.38, 95% CI [0.21-0.68]). For LMR ≥ 6.5, the all-cause mortality risk did not progressively increase. Stratified and subgroup analyses revealed similar results to the main analyses,andE-value analysis suggested robustness to unmeasured confounding.

Conclusions

The study demonstrated that LMR was an independent predictor of all-cause mortality in HCM patients, and LMR may be useful for identifying HCM patients at high mortality risk.

Heart regeneration: 20 years of progress and renewed optimism

Cardiovascular disease is a leading cause of death worldwide, and thus there remains great interest in regenerative approaches to treat heart failure. In the past 20 years, the field of heart regeneration has entered a renaissance period with remarkable progress in the understanding of endogenous heart regeneration, stem cell differentiation for exogenous cell therapy, and cell-delivery methods. In this review, we highlight how this new understanding can lead to viable strategies for human therapy. For the near term, drugs, electrical and mechanical devices, and heart transplantation will remain mainstays of cardiac therapies, but eventually regenerative therapies based on fundamental regenerative biology may offer more permanent solutions for patients with heart failure.

Cardiomyocyte BRAF and type 1 RAF inhibitors promote cardiomyocyte and cardiac hypertrophy in mice in vivo

The extracellular signal-regulated kinase 1/2 (ERK1/2) cascade promotes cardiomyocyte hypertrophy and is cardioprotective, with the three RAF kinases forming a node for signal integration. Our aims were to determine if BRAF is relevant for human heart failure, whether BRAF promotes cardiomyocyte hypertrophy, and if Type 1 RAF inhibitors developed for cancer (that paradoxically activate ERK1/2 at low concentrations: the 'RAF paradox') may have the same effect. BRAF was up-regulated in heart samples from patients with heart failure compared with normal controls. We assessed the effects of activated BRAF in the heart using mice with tamoxifen-activated Cre for cardiomyocyte-specific knock-in of the activating V600E mutation into the endogenous gene. We used echocardiography to measure cardiac dimensions/function. Cardiomyocyte BRAFV600E induced cardiac hypertrophy within 10 d, resulting in increased ejection fraction and fractional shortening over 6 weeks. This was associated with increased cardiomyocyte size without significant fibrosis, consistent with compensated hypertrophy. The experimental Type 1 RAF inhibitor, SB590885, and/or encorafenib (a RAF inhibitor used clinically) increased ERK1/2 phosphorylation in cardiomyocytes, and promoted hypertrophy, consistent with a 'RAF paradox' effect. Both promoted cardiac hypertrophy in mouse hearts in vivo, with increased cardiomyocyte size and no overt fibrosis. In conclusion, BRAF potentially plays an important role in human failing hearts, activation of BRAF is sufficient to induce hypertrophy, and Type 1 RAF inhibitors promote hypertrophy via the 'RAF paradox'. Cardiac hypertrophy resulting from these interventions was not associated with pathological features, suggesting that Type 1 RAF inhibitors may be useful to boost cardiomyocyte function.