Inflammatory Mechanisms of Cardiovascular Remodeling

Resveratrol protects against myocardial ischemic injury via the inhibition of NF‑κB‑dependent inflammation and the enhancement of antioxidant defenses

Resveratrol (RES) is a natural phenol which possesses multiple pharmacological actions. The present study aimed to determine whether RES protects against myocardial ischemic injury in association with the inhibition of NF‑κB‑dependent inflammation and the enhancement of antioxidant defenses in mice following acute myocardial infarction (AMI). Male C57/BL mice were randomly assigned to 3 groups as follows: The sham‑operated (sham) group, AMI + vehicle group and AMI + RES group. Rat H9C2 cells were also used to examine the effects of RES on hypoxia‑induced oxidative injury in vitro. Redox homeostasis in the mouse myocardium and rat H9C2 cells was determined post‑treatment. The mRNA and protein levels of phosphorylated (p‑)IκB kinase (p‑IKK), p‑nuclear factor (NF)‑κB p65, interleukin (IL)‑1β, IL‑6, nerve growth factor (NGF) and insulin‑like growth factor‑1 (IGF‑1) were measured by RT‑qPCR and western blot analysis. It was found that RES slightly protected the myocardium against ischemic injury in mice, while it prevented the hypoxia‑induced apoptosis of H9C2 cells. RES decreased the production of reactive oxygen species (ROS) and enhanced the activities of superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GPx). RES also downregulated the protein and/or mRNA levels of p‑IKK, p‑NF‑κB p65, IL‑1β, IL‑6, NGF and IGF‑1 at 7 and 28 days after infarction. On the whole, these data indicate that RES protects the myocardium against ischemic injury in association with the inhibition of oxidative stress and inflammatory responses. Thus, RES has the potential to be used as an adjunctive therapeutic drug for heart diseases.

Thoracic and abdominal aortic aneurysms: exploring their contrast and genetic associations

Until recently thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) were correlated with atherosclerosis but following a range of cohort studies, a linkage proved unlikely. Instead, data from the Genome wide association study detected two common significantly correlated lncRNA loci: miRNA and the antisense non-coding RNA in the INK4 locus (ANRIL). lncRNAs are sometimes utilized by the body as transcription regulators and signaling molecules. This is crucial in cell transformation and embryology, including that of the mammalian heart. ANRIL, a 19 exon RNA sequence found in the chromosome 9p21 region, will be one of the main focuses of this paper. TAA and AAA have many differences due to their vessel walls but similarities in their gross anatomic structure prove a genetic correlated disease likely. ANRIL has a convincing potential to be used as an additive therapeutic tool in TAA and AAA. This is because Chr9p21 is independent of typical risk factors. However, it remains that further research and clinical studies are required before clinical translation. It is best to consider TAA and AAA separately as the underlying pathophysiology has some distinct differences. They are both commonly diagnosed late, and the hope is that genetic mutations (ANRIL) can act as a biomarker for a faster diagnosis, management and possible treatment alternative.

C-Reactive Protein Triggers Cell Death in Ischemic Cells

C-reactive protein (CRP) is the best-known acute phase protein. In humans, almost every type of inflammation is accompanied by an increase of CRP concentration. Until recently, the only known physiological function of CRP was the marking of cells to initiate their phagocytosis. This triggers the classical complement pathway up to C4, which helps to eliminate pathogens and dead cells. However, vital cells with reduced energy supply are also marked, which is useful in the case of a classical external wound because an important substrate for pathogens is disposed of, but is counterproductive at internal wounds (e.g., heart attack or stroke). This mechanism negatively affects clinical outcomes since it is established that CRP levels correlate with the prognosis of these indications. Here, we summarize what we can learn from a clinical study in which CRP was adsorbed from the bloodstream by CRP-apheresis. Recently, it was shown that CRP can have a direct effect on blood pressure in rabbits. This is interesting in regard to patients with high inflammation, as they often become tachycardic and need catecholamines. These two physiological effects of CRP apparently also occur in COVID-19. Parts of the lung become ischemic due to intra-alveolar edema and hemorrhage and in parallel CRP increases dramatically, hence it is assumed that CRP is also involved in this ischemic condition. It is meanwhile considered that most of the damage in COVID-19 is caused by the immune system. The high amounts of CRP could have an additional influence on blood pressure in severe COVID-19.

YQWY Decoction Improves Myocardial Remodeling via Activating the IL-10/Stat3 Signaling Pathway

Heart failure (HF) has been known as a global health problem, and cardiac remodeling plays an essential role in the development of HF. We hypothesized that YQWY decoction might exert a cardioprotective effect against myocardium inflammation, fibrosis, and apoptosis via activating the interleukin-10 (IL-10)/Stat3 signaling pathway. To test this hypothesis, the HF model in rats was established by pressure overload through the minimally invasive transverse aortic constriction (MTAC). Echocardiography was performed to assess the left ventricular function of rats. Myocardial fibrosis in rats was observed by Masson and Picrosirius red staining, and the degree of myocardial apoptosis was detected via TUNEL staining. In addition, expression levels of IL-10, tumor necrosis factor-α (TNF-α), Stat3 (P-Stat3), P65 (P-P65), CD68, collagen I, TGF-β, CTGF, Bax, Bcl-2, cleaved caspase-3, and PARP in rat serum and myocardium samples were examined by ELISA, western blot, and immunohistochemistry, respectively. YQWY decoction treatment significantly improved left ventricular function in HF rats, especially in those of the high-dose group (LVEF%: 51.29 ± 5.876 vs. 66.02 ± 1.264, P < 0.01;, LVFS%: 27.75 ± 3.757 vs. 37.76 ± 1.137, P < 0.01). Furthermore, YQWY decoction markedly inhibited MTAC-induced myocardial fibrosis as evidenced by downregulated collagen I, TGF-β, and CTGF in myocardium and alleviated apoptosis (downregulated caspase-3 and PARP and increased Bcl-2/Bax ratio in cardiomyocytes). In addition, YQWY decoction decreased the level of the proinflammatory cytokine TNF-α in both circulating blood and myocardium and attenuated infiltration of inflammatory cells in heart tissue from HF rats. Most importantly, YQWY decoction suppressed MTAC-induced NF-κB activation and phosphorylated Stat3 by upregulating IL-10 in rat heart tissues. Our study showed that YQWY decoction could attenuate MTAC-induced myocardial inflammation, fibrosis, apoptosis, and reverse the impairment of cardiac function in rats by activating the IL-10/Stat3 signaling pathway and improving myocardium remodeling. Our findings suggested a therapeutic potential of YQWY decoction in HF.

Neutrophil Elastase Deficiency Ameliorates Myocardial Injury Post Myocardial Infarction in Mice

Neutrophils are recruited into the heart at an early stage following a myocardial infarction (MI). These secrete several proteases, one of them being neutrophil elastase (NE), which promotes inflammatory responses in several disease models. It has been shown that there is an increase in NE activity in patients with MI; however, the role of NE in MI remains unclear. Therefore, the present study aimed to investigate the role of NE in the pathogenesis of MI in mice. NE expression peaked on day 1 in the infarcted hearts. In addition, NE deficiency improved survival and cardiac function post-MI, limiting fibrosis in the noninfarcted myocardium. Sivelestat, an NE inhibitor, also improved survival and cardiac function post-MI. Flow cytometric analysis showed that the numbers of heart-infiltrating neutrophils and inflammatory macrophages (CD11b⁺F4/80⁺CD206^low cells) were significantly lower in NE-deficient mice than in wild-type (WT) mice. At the border zone between intact and necrotic areas, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells was lower in NE-deficient mice than in WT mice. Western blot analyses revealed that the expression levels of insulin receptor substrate 1 and phosphorylation of Akt were significantly upregulated in NE-knockout mouse hearts, indicating that NE deficiency might improve cardiac survival by upregulating insulin/Akt signaling post-MI. Thus, NE may enhance myocardial injury by inducing an excessive inflammatory response and suppressing Akt signaling in cardiomyocytes. Inhibition of NE might serve as a novel therapeutic target in the treatment of MI.

Cardio- and reno-protective effects of dipeptidyl peptidase III in diabetic mice

Diabetes mellitus (DM) causes injury to tissues and organs, including to the heart and kidney, resulting in increased morbidity and mortality. Thus, novel potential therapeutics are continuously required to minimize DM-related organ damage. We have previously shown that dipeptidyl peptidase III (DPPIII) has beneficial roles in a hypertensive mouse model, but it is unknown whether DPPIII has any effects on DM. In this study, we found that intravenous administration of recombinant DPPIII in diabetic db/db mice for 8 weeks suppressed the DM-induced cardiac diastolic dysfunctions and renal injury without alteration of the blood glucose level. This treatment inhibited inflammatory cell infiltration and fibrosis in the heart and blocked the increase in albuminuria by attenuating the disruption of the glomerular microvasculature and inhibiting the effacement of podocyte foot processes in the kidney. The beneficial role of DPPIII was, at least in part, mediated by the cleavage of a cytotoxic peptide, named Peptide 2, which was increased in db/db mice compared with normal mice. This peptide consisted of nine amino acids, was a digested fragment of complement component 3 (C3), and had an anaphylatoxin-like effect determined by the Miles assay and chemoattractant analysis. The effect was dependent on its interaction with the C3a receptor and protein kinase C-mediated RhoA activation downstream of the receptor in endothelial cells. In conclusion, DPPIII plays a protective role in the heart and kidney in a DM animal model through cleavage of a peptide that is a part of C3.

D-galactose-induced toxicity associated senescence mitigated by alpinate oxyphyllae fructus fortified adipose-derived mesenchymal stem cells

This study addresses the effect of D-galactose-induced toxicity associated senescence mitigated by alpinate oxyphyllae fructus (AOF; Alpinia oxyphylla Miq) extracts fortified with adipose-derived mesenchymal stem cells (ADMSCs) in rats. Male 18 week-old Wistar Kyoto (WKY) rats were used in this study. We analyzed cardiac fibrosis by Masson's trichrome staining. The tissue sections were dyed using hematoxylin and eosin (H&E). Tissue sections were stained for the restoration of Nrf2 expression in treatment groups by immunohistochemistry. Immunohistochemistry and western blotting analysis showed that AOF with ADMSCs could significantly reduce aging-induced oxidative stress in D-galactose-induced aging rat hearts by inducing Nrf2 pathway. Reduction in ROS resulted in the suppression of inflammatory signals (p-NF-κB and IL-6). Histopathological studies were showed an increased interstitium and collagen accumulation in aging-induced heart sections. However, AOF and ADMSCs treated hearts were recovered from cardiac remodeling. Furthermore, hypertrophy and fibrosis associated markers were also significantly reduced (P < .05) in treatment groups. We speculate that ADMSCs might activate certain paracrine factors, which could target the upstream activator of aging associated cardiac complications and AOF might provide homing for these stem cells.

Identification of Genetic Biomarkers for Diagnosis of Myocardial Infarction Compared with Angina Patients

Background

Myocardial infarction (MI) is the most terrible appearance of cardiovascular disease. The incidence of heart failure, one of the complications of MI, has increased in the past few decades. Therefore, the identification of MI from angina patients and the determination of new diagnoses and therapies of MI are increasingly important. The present study was aimed at identifying differentially expressed genes and miRNAs as biomarkers for the clinical and prognosis factors of MI compared with angina using microarray data analysis.

Methods

Differentially expressed miRNAs and genes were manifested by GEO2R. The biological function of differentially expressed genes (DEGs) was examined by GO and KEGG. The construction of a protein-protein network was explored by STRING. cytoHubba was utilized to screen hub genes. Analysis of miRNA-gene pairs was executed by the miRWalk 3.0 database. The miRNA-target pairs overlapped with hub genes were seen as key genes. Logistic regressive analysis was performed by SPSS.

Results

A number of 779 DEGs were recorded. The biological function containing extracellular components, signaling pathways, and cell adhesion was enriched. Twenty-four hub genes and three differentially expressed miRNAs were noted. Eight key genes were demonstrated, and 6 out of these 8 key genes were significantly related to clinical and prognosis factors following MI.

Conclusions

CALCA, CDK6, MDM2, NRXN1, SOCS3, VEGFA, SMAD4, NCAM1, and hsa-miR-127-5p were thought to be potential diagnosis biomarkers for MI. Meanwhile, CALCA, CDK6, NRXN1, SMAD4, SOCS3, and NCAM1 were further identified to be potential diagnosis and therapy targets for MI.

MAIR-II deficiency ameliorates cardiac remodelling post-myocardial infarction by suppressing TLR9-mediated macrophage activation

Macrophages are fundamental components of inflammation in post‐myocardial infarction (MI) and contribute to adverse cardiac remodelling and heart failure. However, the regulatory mechanisms in macrophage activation have not been fully elucidated. Previous studies showed that myeloid‐associated immunoglobulin–like receptor II (MAIR‐II) is involved in inflammatory responses in macrophages. However, its role in MI is unknown. Thus, this study aimed to determine a novel role and mechanism of MAIR‐II in MI. We first identified that MAIR‐II–positive myeloid cells were abundant from post‐MI days 3 to 5 in infarcted hearts of C57BL/6J (WT) mice induced by permanent left coronary artery ligation. Compared to WT, MAIR‐II–deficient (Cd300c2^−/−) mice had longer survival, ameliorated cardiac remodelling, improved cardiac function and smaller infarct sizes. Moreover, we detected lower pro‐inflammatory cytokine and fibrotic gene expressions in Cd300c2^−/−‐infarcted hearts. These mice also had less infiltrating pro‐inflammatory macrophages following MI. To elucidate a novel molecular mechanism of MAIR‐II, we considered macrophage activation by Toll‐like receptor (TLR) 9–mediated inflammation. In vitro, we observed that Cd300c2^−/− bone marrow–derived macrophages stimulated by a TLR9 agonist expressed less pro‐inflammatory cytokines compared to WT. In conclusion, MAIR‐II may enhance inflammation via TLR9‐mediated macrophage activation in MI, leading to adverse cardiac remodelling and poor prognosis.

Generation of hypoimmunogenic human pluripotent stem cells via expression of membrane-bound and secreted β2m-HLA-G fusion proteins

Allogeneic immune rejection is a major barrier for the application of human pluripotent stem cells (hPSCs) in regenerative medicine. A broad spectrum of immune cells, including T cells, natural killer (NK) cells, and antigen-presenting cells, which either cause direct cell killing or constitute an immunogenic environment, are involved in allograft immune rejection. A strategy to protect donor cells from cytotoxicity while decreasing the secretion of inflammatory cytokines of lymphocytes is still lacking. Here, we engineered hPSCs with no surface expression of classical human leukocyte antigen (HLA) class I proteins via beta-2 microglobulin (B2M) knockout or biallelic knockin of HLA-G1 within the frame of endogenous B2M loci. Elimination of the surface expression of HLA class I proteins protected the engineered hPSCs from cytotoxicity mediated by T cells. However, this lack of surface expression also resulted in missing-self response and NK cell activation, which were largely compromised by expression of β2m-HLA-G1 fusion proteins. We also proved that the engineered β2m-HLA-G5 fusion proteins were soluble, secretable, and capable of safeguarding low immunogenic environments by lowering inflammatory cytokines secretion in allografts. Our current study reveals a novel strategy that may offer unique advantages to construct hypoimmunogenic hPSCs via the expression of membrane-bound and secreted β2m-HLA-G fusion proteins. These engineered hPSCs are expected to serve as an unlimited cell source for generating universally compatible "off-the-shelf" cell grafts in the future.

Selective Apheresis of C-Reactive Protein for Treatment of Indications with Elevated CRP Concentrations

Almost every kind of inflammation in the human body is accompanied by rising C-reactive protein (CRP) concentrations. This can include bacterial and viral infection, chronic inflammation and so-called sterile inflammation triggered by (internal) acute tissue injury. CRP is part of the ancient humoral immune response and secreted into the circulation by the liver upon respective stimuli. Its main immunological functions are the opsonization of biological particles (bacteria and dead or dying cells) for their clearance by macrophages and the activation of the classical complement pathway. This not only helps to eliminate pathogens and dead cells, which is very useful in any case, but unfortunately also to remove only slightly damaged or inactive human cells that may potentially regenerate with more CRP-free time. CRP action severely aggravates the extent of tissue damage during the acute phase response after an acute injury and therefore negatively affects clinical outcome. CRP is therefore a promising therapeutic target to rescue energy-deprived tissue either caused by ischemic injury (e.g., myocardial infarction and stroke) or by an overcompensating immune reaction occurring in acute inflammation (e.g., pancreatitis) or systemic inflammatory response syndrome (SIRS; e.g., after transplantation or surgery). Selective CRP apheresis can remove circulating CRP safely and efficiently. We explain the pathophysiological reasoning behind therapeutic CRP apheresis and summarize the broad span of indications in which its application could be beneficial with a focus on ischemic stroke as well as the results of this therapeutic approach after myocardial infarction.

Tenascin-C in cardiac disease: a sophisticated controller of inflammation, repair, and fibrosis

Tenascin-C (TNC) is a large extracellular matrix glycoprotein classified as a matricellular protein that is generally upregulated at high levels during physiological and pathological tissue remodeling and is involved in important biological signaling pathways. In the heart, TNC is transiently expressed at several important steps during embryonic development and is sparsely detected in normal adult heart but is re-expressed in a spatiotemporally restricted manner under pathological conditions associated with inflammation, such as myocardial infarction, hypertensive cardiac fibrosis, myocarditis, dilated cardiomyopathy, and Kawasaki disease. Despite its characteristic and spatiotemporally restricted expression, TNC knockout mice develop a grossly normal phenotype. However, various disease models using TNC null mice combined with in vitro experiments have revealed many important functions for TNC and multiple molecular cascades that control cellular responses in inflammation, tissue repair, and even myocardial regeneration. TNC has context-dependent diverse functions and, thus, may exert both harmful and beneficial effects in damaged hearts. However, TNC appears to deteriorate adverse ventricular remodeling by proinflammatory and profibrotic effects in most cases. Its specific expression also makes TNC a feasible diagnostic biomarker and target for molecular imaging to assess inflammation in the heart. Several preclinical studies have shown the utility of TNC as a biomarker for assessing the prognosis of patients and selecting appropriate therapy, particularly for inflammatory heart diseases.

Myocardial slices come to age: an intermediate complexity in vitro cardiac model for translational research

Although past decades have witnessed significant reductions in mortality of heart failure together with advances in our understanding of its cellular, molecular, and whole-heart features, a lot of basic cardiac research still fails to translate into clinical practice. In this review we examine myocardial slices, a novel model in the translational arena. Myocardial slices are living ultra-thin sections of heart tissue. Slices maintain the myocardium's native function (contractility, electrophysiology) and structure (multicellularity, extracellular matrix) and can be prepared from animal and human tissue. The discussion begins with the history and current advances in the model, the different interlaboratory methods of preparation and their potential impact on results. We then contextualize slices' advantages and limitations by comparing it with other cardiac models. Recently, sophisticated methods have enabled slices to be cultured chronically in vitro while preserving the functional and structural phenotype. This is more timely now than ever where chronic physiologically relevant in vitro platforms for assessment of therapeutic strategies are urgently needed. We interrogate the technological developments that have permitted this, their limitations, and future directions. Finally, we look into the general obstacles faced by the translational field, and how implementation of research systems utilizing slices could help in resolving these.

The roles of Qishen granules recipes, Qingre Jiedu, Wenyang Yiqi and Huo Xue, in the treatment of heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Recipes (Qingre Jiedu (QJ), Wenyang Yiqi (WYYQ) and Huo Xue (HX)) in Qishen granules (QSG) are believed to synergistically exert cardio-protective effects. However, the underlying pattern of each decomposed recipe in QSG and their synergistic effects in the treatment of heart failure (HF) are not clear.

OBJECTIVE

The purpose of this study is to explore the biological contributions of decomposed recipes to therapeutic effects of QSG and reveal the pharmacological mechanism of QSG in treating HF.

MATERIALS AND METHODS

The therapeutic effects of QSG or its recipes on heart failure were examined in wet-lab at both transcription and phenotypic level using HF Sprague-Dawley rats. Sequencing and transcriptome analyses were performed using in silico approaches including identification of differentially expressed genes, pathway enrichment and protein-protein interaction network studies. Specially, an optimized in silico quantitative pathway analysis that maximally extracted gene expression information was developed to reveal differentially expressed pathways (DEPs) among various groups, and is publicly available as R package QPA on GitHub (https://github.com/github-gs/QPA). Finally, the HF-related genes predicted using DEP approach were validated by quantitative real-time polymerase chain reaction and western blot.

RESULTS

Multiple key genes and the associated signaling pathways were shown to be highly relevant for the therapeutic effect of QSG. Decreased expression of Spp1 gene required for inflammatory signaling and profibrotic signaling were observed in failing hearts treated with QJ, WYYQ and HX. Decreased expression of Cx3cr1 gene required for inflammatory signaling was observed in failing hearts treated with WYYQ and HX. Decreased expression of Myc gene required for oxidative stress and Fgfr2 gene required for profibrotic signaling were observed in failing hearts treated with HX and WYYQ, respectively. Increased expression of Adcy1 gene required for cAMP-PKA signaling cascade was observed in failing hearts treated with WYYQ and HX.

CONCLUSIONS

Our study suggests that QJ, WYYQ and HX recipes in QSG achieve synergistic and complementary therapeutic effects through alleviating inflammatory responses, attenuating ventricular remodeling and enhancing myocardial energy supply.

Euploid miscarriage is associated with elevated serum C-reactive protein levels in infertile women: a pilot study

Purpose

Increased serum C-protein (CRP) levels reduce fecundity in healthy eumenorrheic women with 1–2 pregnancy losses. Subclinical systemic inflammation may impede maternal immune tolerance toward the fetal semi-allograft, compromising implantation and early embryonic development. Some miscarriages with normal karyotypes could, therefore, be caused by inflammation. Whether pre-pregnancy CRP relates to karyotypes of spontaneously aborted products of conception (POCs) was investigated.

Methods

A study cohort of 100 infertile women with missed abortions who underwent vacuum aspirations followed by cytogenetic analysis of their products of conception tissue was evaluated at an academically affiliated fertility center. Since a normal female fetus cannot be differentiated from maternal cell contamination (MCC) in conventional chromosomal analyses, POC testing was performed by chromosomal microarray analysis. MCC cases and incomplete data were excluded. Associations of elevated CRP with first trimester pregnancy loss in the presence of a normal fetal karyotype were investigated.

Results

Mean patients’ age was 39.9 ± 5.8 years; they demonstrated a BMI of 23.9 ± 4.6 kg/m² and antiMullerian hormone (AMH) of 1.7 ± 2.4 ng/mL; 21.3% were parous, 19.1% reported no prior pregnancy losses, 36.2% 1–2 and 6.4% ≥ 3 losses. Karyotypes were normal in 34% and abnormal in 66%. Adjusted for BMI, women with elevated CRP were more likely to experience euploid pregnancy loss (p = 0.03). This relationship persisted when controlled for female age and AMH.

Conclusions

Women with elevated CRP levels were more likely to experience first trimester miscarriage with normal fetal karyotype. This relationship suggests an association between subclinical inflammation and miscarriage.

Heart Plasticity in Response to Pressure- and Volume-Overload: A Review of Findings in Compensated and Decompensated Phenotypes

The adult human heart has an exceptional ability to alter its phenotype to adapt to changes in environmental demand. This response involves metabolic, mechanical, electrical, and structural alterations, and is known as cardiac plasticity. Understanding the drivers of cardiac plasticity is essential for development of therapeutic agents. This is particularly important in contemporary cardiology, which uses treatments with peripheral effects (e.g., on kidneys, adrenal glands). This review focuses on the effects of different hemodynamic loads on myocardial phenotype. We examine mechanical scenarios of pressure- and volume overload, from the initial insult, to compensated, and ultimately decompensated stage. We discuss how different hemodynamic conditions occur and are underlined by distinct phenotypic and molecular changes. We complete the review by exploring how current basic cardiac research should leverage available cardiac models to study mechanical load in its different presentations.

Targeted anti-IL-1β platelet microparticles for cardiac detoxing and repair

An acute myocardial infarction (AMI) induces a sterile inflammatory response that facilitates further heart injury and promotes adverse cardiac remodeling. Interleukin-1β (IL-1β) plays a central role in the sterile inflammatory response that results from AMI. Thus, IL-1β blockage is a promising strategy for treatment of AMI. However, conventional IL-1β blockers lack targeting specificity. This increases the risk of serious side effects. To address this problem herein, we fabricated platelet microparticles (PMs) armed with anti-IL-1β antibodies to neutralize IL-1β after AMI and to prevent adverse cardiac remodeling. Our results indicate that the infarct-targeting PMs could bind to the injured heart, increasing the number of anti-IL-1β antibodies therein. The anti-IL-1β platelet PMs (IL1-PMs) protect the cardiomyocytes from apoptosis by neutralizing IL-1β and decreasing IL-1β-driven caspase-3 activity. Our findings indicate that IL1-PM is a promising cardiac detoxification agent that removes cytotoxic IL-1β during AMI and induces therapeutic cardiac repair.

Bispecific Antibody Inhalation Therapy for Redirecting Stem Cells from the Lungs to Repair Heart Injury

Stem cell therapy is a promising strategy for cardiac repair. However, clinical efficacy is hampered by poor cell engraftment and the elusive repair mechanisms of the transplanted stem cells. The lung is a reservoir of hematopoietic stem cells (HSCs) and a major biogenesis site for platelets. A strategy is sought to redirect lung resident stem cells to the injured heart for therapeutic repair after myocardial infarction (MI). To achieve this goal, CD34-CD42b platelet-targeting bispecific antibodies (PT-BsAbs) are designed to simultaneously recognize HSCs (via CD34) and platelets (via CD42b). After inhalation delivery, PT-BsAbs reach the lungs and conjoined HSCs and platelets. Due to the innate injury-finding ability of platelets, PT-BsAbs guide lung HSCs to the injured heart after MI. The redirected HSCs promote endogenous repair, leading to increased cardiac function. The repair mechanism involves angiomyogenesis and inflammation modulation. In addition, the inhalation route is superior to the intravenous route to deliver PT-BsAbs in terms of the HSCs' homing ability and therapeutic benefits. This work demonstrates that this novel inhalable antibody therapy, which harnesses platelets derived from the lungs, contributes to potent stem cell redirection and heart repair. This strategy is safe and effective in a mouse model of MI.

Potential of mesenchymal- and cardiac progenitor cells for therapeutic targeting of B-cells and antibody responses in end-stage heart failure

Upon myocardial damage, the release of cardiac proteins induces a strong antibody-mediated immune response, which can lead to adverse cardiac remodeling and eventually heart failure (HF). Stem cell therapy using mesenchymal stromal cells (MSCs) or cardiomyocyte progenitor cells (CPCs) previously showed beneficial effects on cardiac function despite low engraftment in the heart. Paracrine mediators are likely of great importance, where, for example, MSC-derived extracellular vesicles (EVs) also show immunosuppressive properties in vitro. However, the limited capacity of MSCs to differentiate into cardiac cells and the sufficient scaling of MSC-derived EVs remain a challenge to clinical translation. Therefore, we investigated the immunosuppressive actions of endogenous CPCs and CPC-derived EVs on antibody production in vitro, using both healthy controls and end-stage HF patients. Both MSCs and CPCs strongly inhibit lymphocyte proliferation and antibody production in vitro. Furthermore, CPC-derived EVs significantly lowered the levels of IgG1, IgG4, and IgM, especially when administered for longer duration. In line with previous findings, plasma cells of end-stage HF patients showed high production of IgG3, which can be inhibited by MSCs in vitro. MSCs and CPCs inhibit in vitro antibody production of both healthy and end-stage HF-derived immune cells. CPC-derived paracrine factors, such as EVs, show similar effects, but do not provide the complete immunosuppressive capacity of CPCs. The strongest immunosuppressive effects were observed using MSCs, suggesting that MSCs might be the best candidates for therapeutic targeting of B-cell responses in HF.

Detection of Active Inflammation Status Around Ventricular Aneurysms in Patients With Cardiac Sarcoidosis

BACKGROUND

Little is known about the pattern of isotope accumulation in the heart on ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography in patients with cardiac sarcoidosis (CS) complicated by ventricular aneurysm (VA).Methods and Results:We prospectively enrolled 82 consecutive patients with CS; 54 patients with active CS (presence of abnormal ¹⁸F-FDG accumulation in the heart) were subdivided into VA (n=17) and non-VA groups (n=37). Strong ¹⁸F-FDG accumulation surrounding the VA and its disappearance in the VA center was observed in all patients with VA, probably because of scar formation at the VA. Peak standardized uptake value was higher around the VA than in the VA center (5.1±2.1 vs. 2.2±0.6, P=0.0003) and the VA center had no ¹⁸F-FDG accumulation (VA center: 2.2±0.6 vs. control area: 2.1±0.6, P=0.37). On the other hand, in non-VA patients with LV wall thinning (n=28), ¹⁸F-FDG accumulation was significantly high, even in the area of LV wall thinning (LV wall thinning area: 3.1±0.8 vs. control area: 2.0±0.6, P=0.00002).

CONCLUSIONS

A pattern of strong ¹⁸F-FDG accumulation surrounding the VA and its disappearance in the VA center might be characteristic in patients with CS complicated by VA. Careful attention to FDG uptake would further elucidate CS pathophysiology and aid in the early treatment of VA.

Inflammation in myocardial disease: From myocarditis to dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is a heterogeneous group of myocardial diseases clinically defined by the presence of left ventricular dilatation and contractile dysfunction. Among various causes of DCM, a progression from viral myocarditis to DCM has long been hypothesized. Supporting this possibility, studies by endomyocardial biopsy, the only method to obtain a definite diagnosis of myocarditis at present, have provided evidence of inflammation in the myocardium in DCM patients. A number of experimental studies have elucidated a cell-mediated autoimmune mechanism triggered by viral infection in the progression of myocarditis to DCM. In addition, the important role of inflammation in the pathogenesis of heart failure has been recognized, and many terms including myocarditis, inflammatory cardiomyopathy, and inflammatory DCM have been used for myocardial diseases associated with inflammation. This review discusses the pathophysiology of inflammation in the myocardium, and refers to diagnosis and treatment based on these concepts.

Association between Galectin-3 levels within central and peripheral venous blood, and adverse left ventricular remodelling after first acute myocardial infarction

Our study investigates association between Galectin-3 levels and adverse left ventricular remodelling (LVR) at six months. Fifty-seven patients following first acute myocardial infarction (AMI) were enrolled in this study and blood samples collected on day 1 from the femoral vein and artery, the right atrium near the coronary sinus and the aortic root, and on day 30, from the cubital vein. Patients with LVESV ≥20% at six months, were included in the LVR group. On day 1, Galectin-3 plasma levels in the femoral vein (10.34 ng/ml ± 3.81 vs 8.22 ng/ml ± 2.34, p = 0.01), and near coronary sinus (10.7 ng/ml ± 3.97 vs 8.41 ng/ml ± 2.56, p = 0.007) were higher in the LVR group. Positive correlations between Galectin-3 levels from aortic root and coronary sinus, aortic root and femoral vein, and coronary sinus and femoral vein, were observed in both groups. On day 30, Galectin-3 concentration in the cubital vein was an independent risk factor of LVR six months post-AMI, demonstrating 1.5-fold increased risk. Day-30 Galectin-3 also showed positive correlations with echocardiography parameters indicative of diastolic and systolic dysfunction. Determining Galectin-3 plasma concentration on day 30 following AMI could have beneficial prognostic value in predicting LVR.

Associations among circulating levels of follistatin-like 1, clinical parameters, and cardiovascular events in patients undergoing elective percutaneous coronary intervention with drug-eluting stents

OBJECTIVES

Follistatin-like 1 (FSTL1) is a glycoprotein secreted by skeletal muscle cells and cardiac myocytes. Previous studies showed that serum FSTL1 concentrations were increased in acute coronary syndrome and chronic heart failure. The aim of this study was to assess the associations among plasma FSTL1 concentration, clinical parameters, and whether FSTL1 concentration could predict cardiovascular events in patients with elective percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A consecutive series of 410 patients who underwent elective PCI with drug-eluting stents (DES) were enrolled between August 2004 and December 2006 at Juntendo University hospital. We measured plasma FSTL1 levels prior to elective PCI and assessed the association among FSTL1 levels, clinical parameters, and occurrence of major adverse cardiac or cerebrovascular events (MACCE) defined as cardiac death, nonfatal myocardial infarction, unstable angina, stroke, and hospitalization for heart failure. FSTL1 concentration was positively correlated with high-sensitivity C-reactive protein (hsCRP), serum creatinine, and N-terminal pro b-type natriuretic peptide (all P < 0.01). After excluding patients with creatinine clearance < 60 mL/min and hsCRP ≥ 0.2 mg/dL, the remaining 214 were followed for a median of 5.1 years. Twenty (9.3%) patients experienced MACCE. Receiver operating characteristics curve analysis estimated an FSTL1 cutoff of 41.1 ng/mL to predict MACCE occurrence. Kaplan-Meier analysis found a higher MACCE rate in patients with high (≥ 41.1 ng/mL) than with low (< 41.1 ng/mL) FSTL1 (P < 0.01). Multivariate Cox hazard analysis found that high FSTL1 was an independent predictor of MACCE (hazard ratio 4.54, 95% confidence interval: 1.45-20.07, P < 0.01).

CONCLUSION

High plasma FSTL1 may be a predictor of cardiovascular events in patients who underwent elective PCI with DES, especially with preserved renal function and low hsCRP.

Effect of the peptides Relaxin, Neuregulin, Ghrelin and Glucagon-like peptide-1, on cardiomyocyte factors involved in the molecular mechanisms leading to diastolic dysfunction and/or heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) represents an important cardiac condition because of its increasing prevalence, resistance to treatment and high associated morbidity and mortality. Two of the major mechanisms responsible for HFpEF are impaired cardiomyocyte sarcoplasmic reticulum (SR) Ca²⁺ ATPase (SERCA2a), which is responsible for calcium reuptake into the SR, and cardiac fibroblasts/myofibroblasts that produce collagen or myocardial fibrosis. Phospholamban (PLB), in the SR and endoplasmic reticulum, is the primary regulator of SERCA2a in the heart and acts as a reversible inhibitor of SERCA2a. Glucagon-like peptide-1, a 30 amino acid peptide, improves diastolic function through increasing SERCA2a expression and activity as well as by decreasing phosphorylation of Ryanodine receptors. It also enhances collagen production through enhanced procollagen IalphaI/IIIalphaI, connective tissue growth factor, fibronectin, TGF-β3 as well as Interleukin -10, -1beta, and -6 gene expression. Relaxin-2, a two chain, 53 amino acid peptide, increases Ser16- and Thr17-phosphorylation levels of PLB, thereby relieving SERCA2a of its inhibition. H3 Relaxin inhibits TGF-β1-stimulated collagen deposition through H3 relaxin-induced increases in pSmad2. Neuregulin-1, an epidermal growth factor, induces nitric oxide and PI-3 kinase activation that enhance SERCA2 activity. Neuregulin-1 was associated with less myocardial macrophage infiltration and cytokine expression reducing collagen deposition. Ghrelin, a 28 amino acid peptide, improves SERCA2a function by inducing PLB phosphorylation. Ghrelin also reduces cardiac fibrosis. In summary, Glucagon-like peptide-1, Relaxin-2, Neuregulin-1, and Ghrelin each modify calcium dynamics, collagen expression, and myocardial fibrosis through attenuation of deleterious signaling cascades, and induction of adaptive pathways, representing potential therapeutic targets for HFpEF.

Implications of the transcription factor WT1 linked to the pathologic cardiac remodeling post-myocardial infarction

New advances in the treatment of acute myocardial infarction involve novel signaling pathways and cellular progeny. In this sense, regeneration is a novel tool that would contribute to post-infarction physiological ventricular remodeling. More specifically, re-expression of the WT1 transcription factor in the myocardial wall by ischemia and infarction would be related to the invasion of cells with the capacity for regeneration. This mechanism seems not to be sufficient to restore muscle cells and lost vessels entirely. Of particular interest, the presence of the heat-shock response protein 70 (Hsp70) and its interaction with the vitamin D receptor would modulate the expression of WT1 positively. In this context, it is proposed that the activation of vitamin D receptors associated with Hsp70 could favor physiological cardiac remodeling and reduce the progression to heart failure.

Angiotensin-(1-9) reduces cardiovascular and renal inflammation in experimental renin-independent hypertension

Hypertension-induced cardiovascular and renal damage can be mediated by activation of the renin-angiotensin-aldosterone system. There are different factors beyond renin-angiotensin-aldosterone system involved in hypertension and renal damage. Inflammation has emerged as an important mediator of hypertension and cardiovascular and kidney damage. Angiotensin-(1-9), a peptide of the renin-angiotensin system, counter-regulates both the physiological and pathological actions of angiotensin II. Recent data has shown that angiotensin-(1-9) protects the heart and blood vessels from adverse cardiovascular remodeling in experimental models of hypertension and/or heart failure and reduces cardiac fibrosis in stroke-prone, spontaneously hypertensive rats. These effects are mediated by the angiotensin II type 2 receptor (AT2R). However, it remains unknown whether angiotensin-(1-9) also has an anti-inflammatory effect. In the present study, we investigate whether angiotensin-(1-9) reduces inflammation and fibrosis in the heart, arteries, and kidney in a DOCA-salt hypertensive model and explore the mechanisms underlying the amelioration of end-organ damage. DOCA-salt hypertensive rats received: a) vehicle, b) angiotensin-(1-9), c) PD123319 (AT2R blocker), d) angiotensin-(1-9) plus A779 (a Mas receptor blocker) or e) angiotensin-(1-9) plus PD123319, and sham rats were used as a control. Our results showed that angiotensin-(1-9) decreased hypertension and increased vasodilation in DOCA-salt hypertensive rats. These actions were partially inhibited by PD123319. Moreover, angiotensin-(1-9) decreased diuresis, fibrosis, and inflammation. These beneficial effects were not mediated by Mas or AT2R blockers. We concluded that angiotensin-(1-9) protects against volume overload-induced hypertensive cardiovascular and kidney damage by decreasing inflammation in the heart, aortic wall, and kidney, through mechanisms independent of the Mas or AT2R.