CCL17 acts as a novel therapeutic target in pathological cardiac hypertrophy and heart failure

LuQi formula ameliorates pressure overload-induced heart failure by regulating macrophages and regulatory T cells

BACKGROUND

Inflammatory macrophages in failing myocardium secrete CCL17, which targets CCR4 in immunosuppressive Tregs and inhibits the intracellular second messenger ARRB2-mediated cardiac chemotaxis. Traditional Chinese medicine (TCM) LuQi formula (LQF) is safe and effective in treating heart failure (HF). This study aims to elucidate the cardioprotective mechanism of LQF through its modulation of cardiac macrophages and Tregs.

METHODS

In vivo, the HF mouse model was established via transverse aortic constriction (TAC), with the superagonistic anti-CD28 monoclonal antibody (CD28-SA)-induced Tregs expansion as a positive control. Proteomics analysis elucidated the core link of LQF in anti-HF. In vitro, bone marrow-derived macrophages (BMDMs) were isolated, and Naive CD4+T cells were sorted and stimulated to differentiate into Tregs. The pharmacological mechanism of LQF was confirmed through histological and molecular biology experiments.

RESULTS

Proteomics reveals that LQF modulates the immune microenvironment of failing myocardium. We revealed that LQF inhibited cardiac inflammatory macrophage infiltration and NF-κB (p50, p65)/CCL17 axis expression, and promoted cardiac Tregs recruitment against HF, with the comparable efficacy of CD-SA28-induced Tregs expansion. Mechanistically, LQF inhibited the NF-κB activator 1-induced NF-κB (p50, p65)/CCL17 axis overexpression, and JSH-23 (NF-κB Inhibitor) abolished NF-κB (p50, p65)/CCL17 axis expression in inflammatory macrophages. Furthermore, the inhibition of CCL17 expression in inflammatory macrophages by LQF was found to be mediated by NF-κB (p50, p65). LQF concentration-dependently promoted Tregs CD73/Foxp3 axis expression, enhancing Tregs immunosuppressive function. LQF activated CCR4-ARRB2 complex and CCR4/ARRB2 axis expression in Tregs. Although AZD2098 (CCR4 Inhibitor) blocked CCR4 expression and CCR4-ARRB2 complex, LQF promoted ARRB2-mediated Tregs cardiac chemotaxis independent of the CCR4. We revealed that NF-κB p50SEP337-CCL17, NF-κB p65SEP536-CCL17, and CCR4-ARRB2 highly bound subunit interface targets. Molecular docking analysis demonstrated that the LQF's active ingredients exhibit good binding affinity with the NF-κB (p50, p65) /CCL17 axis in macrophages and Foxp3 in Tregs.

CONCLUSION

LQF has the potential to enhance the cardiac immune microenvironment and effectively prevent and treat HF by modulating both innate and adaptive immune responses. It achieves this by inhibiting the infiltration of inflammatory macrophages, suppressing the NF-κB (p50, p65)/CCL17 axis, and promoting Tregs recruitment. The active ingredients of LQF provide valuable candidate compounds for developing new anti-HF drugs. Furthermore, CD-28SA-induced Tregs expansion showed cardioprotective effects in TAC-induced non-ischemic HF models.

Cellular senescence as a key player in chronic heart failure pathogenesis: Unraveling mechanisms and therapeutic opportunities

Chronic heart failure (CHF) is the final stage of heart disease and is caused by various factors. Unfortunately, CHF has a poor prognosis and a high mortality rate. Recent studies have found that aging is a significant risk factor for the development of CHF and that cellular senescence plays a vital role in its development. This article reviews different types of cellular senescence, mitochondrial dysfunction in senescent cells, autophagy in senescent cells, and senescence-associated secretory phenotype (SASP), and epigenetic regulation, to provide new perspectives on the research and treatment of CHF.

Role of chemokines in aging and age-related diseases

Chemokines (chemotactic cytokines) play essential roles in developmental process, immune cell trafficking, inflammation, immunity, angiogenesis, cellular homeostasis, aging, neurodegeneration, and tumorigenesis. Chemokines also modulate response to immunotherapy, and consequently influence the therapeutic outcome. The mechanisms underlying these processes are accomplished by interaction of chemokines with their cognate cell surface G protein-coupled receptors (GPCRs) and subsequent cellular signaling pathways. Chemokines play crucial role in influencing aging process and age-related diseases across various tissues and organs, primarily through inflammatory responses (inflammaging), recruitment of macrophages, and orchestrated trafficking of other immune cells. Chemokines are categorized in four distinct groups based on the position and number of the N-terminal cysteine residues; namely, the CC, CXC, CX3C, and (X)C. They mediate inflammatory responses, and thereby considerably impact aging process across multiple organ-systems. Therefore, understanding the underlying mechanisms mediated by chemokines may be of crucial importance in delaying and/or modulating the aging process and preventing age-related diseases. In this review, we highlight recent progress accomplished towards understanding the role of chemokines and their cellular signaling pathways involved in aging and age-relaed diseases of various organs. Moreover, we explore potential therapeutic strategies involving anti-chemokines and chemokine receptor antagonists aimed at reducing aging and mitigating age-related diseases. One of the modern methods in this direction involves use of chemokine receptor antagonists and anti-chemokines, which suppress the pro-inflammatory response, thereby helping in resolution of inflammation. Considering the wide-spectrum of functional involvements of chemokines in aging and associated diseases, several clinical trials are being conducted to develop therapeutic approaches using anti-chemokine and chemokine receptor antagonists to improve life span and promote healthy aging.

Identification of potential biomarkers associated with cuproptosis and immune microenvironment analysis in acute myocardial infarction: A diagnostic accuracy study

Acute myocardial infarction (AMI), a critical cardiovascular condition, is often associated with serious health risks. Recent studies suggest a link between copper-induced apoptosis and immune cell infiltration. Specifically, abnormal accumulation of copper ions can lead to intracellular oxidative stress and apoptosis, while also affecting immune cell function and infiltration. Nevertheless, studies exploring this relationship in the context of AMI are notably scarce, underscoring the necessity of identifying biomarkers associated with cuproptosis in AMI. Consensus clustering analysis was employed to classify distinct subtypes of AMI in the GSE66360 dataset. Concurrently, differential expression analysis was performed to identify differentially expressed genes (DEGs) across subtypes and between AMI and control samples. We employed Venn diagrams to validate the selection of cuproptosis-related DEGs in patients with AMI. A protein-protein interaction network was constructed to pinpoint potential candidate genes. Receiver operating characteristic curves were generated to identify promising biomarkers. The immune infiltration milieu was analyzed using CIBERSORT algorithms. Finally, the expression levels of identified cuproptosis-related biomarkers were validated at the transcriptional level. We classified AMI into 2 distinct cuproptosis-related subtypes, leading to the identification of 157 cuproptosis-related DEGs. Further analysis refined this list to 10 potential candidate genes. Among these, 5 emerged as significant biomarkers for AMI: granzyme A (GZMA), GTPase immunity-associated proteins (GIMPAs) GIMAP7, GIMAP5, GIMAP6, and TRAF3 interacting protein 3 (TRAF3IP3). A comprehensive examination of immune infiltration in AMI samples revealed significant differences in the levels of 11 types of immune cells, with GZMA displaying the highest correlation with activated mast cells and CD8 + T cells. We observed markedly lower expression levels of GZMA, GIMAP6, and TRAF3IP3 in the AMI group compared to controls. This study identified 5 cuproptosis-related biomarkers (GZMA, GIMAP7, GIMAP5, GIMAP6, and TRAF3IP3) associated with AMI, laying a theoretical foundation for the treatment of AMI.

The aging heart in focus: The advanced understanding of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) accounts for 50 % of heart failure (HF) cases, making it the most common type of HF, and its prevalence continues to increase in the aging society. HFpEF is a systemic syndrome resulting from many risk factors, such as aging, metabolic syndrome, and hypertension, and its clinical features are highly heterogeneous in different populations. HFpEF syndrome involves the dysfunction of multiple organs, including the heart, lung, muscle, and vascular system. The heart shows dysfunction of various cells, including cardiomyocytes, endothelial cells, fibroblasts, adipocytes, and immune cells. The complex etiology and pathobiology limit experimental research on HFpEF in animal models, delaying a comprehensive understanding of the mechanisms and making treatment difficult. Recently, many scientists and cardiologists have attempted to improve the clinical outcomes of HFpEF. Recent advances in clinically related animal models and systemic pathology studies have improved our understanding of HFpEF, and clinical trials involving sodium-glucose cotransporter 2 inhibitors have significantly enhanced our confidence in treating HFpEF. This review provides an updated comprehensive discussion of the etiology and pathobiology, molecular and cellular mechanisms, preclinical animal models, and therapeutic trials in animals and patients to enhance our understanding of HFpEF and improve clinical outcomes.

Pleiotropic role of CCR9/CCL25 signaling in adriamycin-induced cardiomyopathy

INTRODUCTION

Adriamycin (ADR)-induced cardiomyopathy is a common problem in many cancer survivors. Recently, specific chemokine receptors have garnered interest as therapeutic targets in cardiovascular diseases.

OBJECTIVES

This study aim to report the role of C-C chemokine receptor 9 (CCR9)/C-C chemokine ligand 25 (CCL25) and its therapeutic potential in ADR-induced cardiomyopathy.

METHODS

Functional gene knockout and overexpression mouse models were utilized to investigate the role of CCR9 against ADR-induced cardiomyopathy. Transcriptome sequencing was also performed to identify the downstream molecular mechanisms of CCR9.

RESULTS

This study revealed that CCR9 and CCL25 levels were increased in mice and HL-1 cells injured by ADR, consistent with the results of patients with heart failure. Both in vivo and in vitro, CCR9 overexpression overtly aggravated cardiac dysfunction, accompanied by decreased AMPK activity and increased mitochondrial dysfunction, fibrosis, oxidative stress, and apoptosis. However, the cardiac harmful effects of ADR were reserved by CCR9 knockdown, as well as CCR9 overexpression aggravated cardiotoxicity were reserved by AMPK agonist GSK621. By constructing different domain-missing CCR9 mutants, we suspected that the △4 region of CCR9 is important for AMPK activity. Furthermore, transcriptome sequencing  further illustrated the mechanism of CCR9 overexpression aggravated ADR-induced cardiotoxicity, which was associated with CYP1A1. Finally, lithospermic acid (LA) was screened and alleviated ADR-induced cardiotoxicity through regulation of CCR9/CCL25-AMPK signaling, bolstering CCR9-targeted potential clinical application.

CONCLUSION

These findings present a promising target and drug for treating chemotherapy-induced cardiotoxicity.

APOB and CCL17 as mediators in the protective effect of SGLT2 inhibition against myocardial infarction: Insights from proteome-wide mendelian randomization

AIMS

Sodium-glucose cotransporter 2 (SGLT2) inhibitors offer a novel therapeutic avenue for myocardial infarction (MI). However, the exact nature of this relationship and the underlying mechanisms are not fully understood.

METHODS

Utilizing a two-sample Mendelian Randomization (MR) analysis, we elucidated the causal effects stemming from the inhibition of SGLT2 on MI. Then, The pool of 4907 circulating proteins within the plasma proteome were utilized to explore the mediators of SGLT2 inhibitors on MI. Protein-protein network and enrichment analysis were conducted to clarify the potential mechanism. Finally, employing MR analysis and meta-analysis techniques, we systematically assessed the causal associations between SGLT2 inhibition and coronary heart diseases (CHD).

RESULTS

SGLT2 inhibition (per 1 SD decrement in HbA1c) was associated with reduced risk of MI (odds ratio [OR] = 0.462, [95% CI 0.222, 0.958], P = 0.038). Among 4907 circulating proteins, we identified APOB and CCL17 which were related to both SGLT2 inhibition and MI. Mediation analysis showed evidence of the indirect effect of SGLT2 inhibition on MI through APOB (β = -0.557, 95%CI [-1.098, -0.155]) with a mediated proportion of 72%, and CCL17 (β = -0.176, 95%CI [-0.332, -0.056]) with a mediated proportion of 17%. The meta-analysis result showed that SGLT2 inhibition was associated with a lower risk of CHD.

CONCLUSION

Based on proteome-wide mendelian randomization, APOB and CCL17 were seen as mediators in the protective effect of SGLT2 inhibition against myocardial infarction.

lncRNA Gm20257 alleviates pathological cardiac hypertrophy by modulating the PGC-1α-mitochondrial complex IV axis

Pathological cardiac hypertrophy, a major contributor to heart failure, is closely linked to mitochondrial function. The roles of long noncoding RNAs (lncRNAs), which regulate mitochondrial function, remain largely unexplored in this context. Herein, a previously unknown lncRNA, Gm20257, was identified. It markedly increased under hypertrophic stress in vivo and in vitro. The suppression of Gm20257 by using small interfering RNAs significantly induced cardiomyocyte hypertrophy. Conversely, the overexpression of Gm20257 through plasmid transfection or adeno-associated viral vector-9 mitigated angiotensin II-induced hypertrophic phenotypes in neonatal mouse ventricular cells or alleviated cardiac hypertrophy in a mouse TAC model respectively, thus restoring cardiac function. Importantly, Gm20257 restored mitochondrial complex IV level and enhanced mitochondrial function. Bioinformatics prediction showed that Gm20257 had a high binding score with peroxisome proliferator-activated receptor coactivator-1 (PGC-1α), which could increase mitochondrial complex IV. Subsequently, Western blot analysis results revealed that Gm20257 substantially affected the expression of PGC-1α. Further analyses through RNA immunoprecipitation and immunoblotting following RNA pull-down indicated that PGC-1α was a direct downstream target of Gm20257. This interaction was demonstrated to rescue the reduction of mitochondrial complex IV induced by hypertrophic stress and promote the generation of mitochondrial ATP. These findings suggest that Gm20257 improves mitochondrial function through the PGC-1α-mitochondrial complex IV axis, offering a novel approach for attenuating pathological cardiac hypertrophy.

MiR-203 improves cardiac dysfunction by targeting PARP1-NAD+ axis in aging murine

Heart aging is a prevalent cause of cardiovascular diseases among the elderly. NAD+ depletion is a hallmark feature of aging heart, however, the molecular mechanisms that affect NAD+ depletion remain unclear. In this study, we identified microRNA-203 (miR-203) as a senescence-associated microRNA that regulates NAD+ homeostasis. We found that the blood miR-203 level negatively correlated with human age and its expression significantly decreased in the hearts of aged mice and senescent cardiomyocytes. Transgenic mice with overexpressed miR-203 (TgN (miR-203)) showed resistance to aging-induced cardiac diastolic dysfunction, cardiac remodeling, and myocardial senescence. At the cellular level, overexpression of miR-203 significantly prevented D-gal-induced cardiomyocyte senescence and mitochondrial damage, while miR-203 knockdown aggravated these effects. Mechanistically, miR-203 inhibited PARP1 expression by targeting its 3'UTR, which helped to reduce NAD+ depletion and improve mitochondrial function and cell senescence. Overall, our study first identified miR-203 as a genetic tool for anti-heart aging by restoring NAD+ function in cardiomyocytes.

Astragaloside IV alleviates LPS-induced cardiomyocyte hypertrophy and collagen expression associated with CCL2-mediated activation of NF-κB signaling pathway

Cardiac remodeling (CR), characterized by cardiac hypertrophy and fibrosis, leads to the development and progression of heart failure (HF). Nowadays, emerging evidence implicated that inflammation plays a vital role in the pathogenesis of CR and HF. Astragaloside IV (AS-IV), an effective component of Astragalus membranaceus, exerts cardio-protective and anti-inflammatory effects, but the underlying mechanism remains not fully elucidated. This present study aimed to investigate the effects of AS-IV on cardiac hypertrophy and fibrosis in cultured H9C2 cells stimulated with LPS, as well as explore its underlying mechanisms. As a result, we found AS-IV could reduce the cell surface size, ameliorate cardiac hypertrophy and fibrosis in LPS-induced H9C2 cells. To specify which molecules or signaling pathways play key roles in the process, RNA-seq analysis was performed. After analyzing the transcriptome data, CCL2 has captured our attention, of which expression was sharply increased in model group and reversed by AS-IV treatment. The results also indicated that AS-IV could ameliorate the inflammatory response by down-regulating NF-κB signaling pathway. Additionally, a classical inhibitor of CCL2 (bindarit) were used to further explore whether the anti-inflammatory effect of AS-IV was dependent on this chemokine. Our results indicated that AS-IV could exert a potent inhibitory effect on CCL2 expression and down-regulated NF-κB signaling pathway in a CCL2-dependent manner. These findings provided a scientific basis for promoting the treatment of HF with AS-IV.

Human amnion epithelial cell therapy reduces hypertension-induced vascular stiffening and cognitive impairment

Vascular inflammation and fibrosis are hallmarks of hypertension and contribute to the development of cardiovascular disease and cognitive impairment. However, current anti-hypertensive drugs do not treat the underlying tissue damage, such as inflammation-associated fibrosis. Human amnion epithelial cells have several properties amenable for treating vascular pathology. This study tested the effect of amnion epithelial cells on vascular pathology and cognitive impairment during hypertension. Male C57Bl6 mice (8-12 weeks) were administered vehicle (saline; n = 58) or angiotensin II (0.7 mg/kg/d, n = 56) subcutaneously for 14 d. After surgery, a subset of mice were injected with 106 amnion epithelial cells intravenously. Angiotensin II infusion increased systolic blood pressure, aortic pulse wave velocity, accumulation of aortic leukocytes, and aortic mRNA expression of collagen subtypes compared to vehicle-infused mice (n = 9-11, P < 0.05). Administration of amnion epithelial cells attenuated these effects of angiotensin II (P < 0.05). Angiotensin II-induced cognitive impairment was prevented by amnion epithelial cell therapy (n = 7-9, P < 0.05). In the brain, amnion epithelial cells modulated some of the inflammatory genes that angiotensin II promoted differential expression of (n = 6, p-adjusted < 0.05). These findings suggest that amnion epithelial cells could be explored as a potential therapy to inhibit vascular pathology and cognitive impairment during hypertension.

Upregulation of mitochondrial telomerase reverse transcriptase mediates the preventive effect of physical exercise on pathological cardiac hypertrophy via improving mitochondrial function and inhibiting oxidative stress

Physical exercise is a non-pharmacological intervention that helps prevent pathological cardiac hypertrophy. However, the underlying molecular mechanisms remain unclear. Telomerase reverse transcriptase (TERT) has non-telomeric functions such as protection against mitochondrial dysfunction and oxidative stress, and its myocardial expression is upregulated by physical exercise. Here, we found that physical exercise caused myocardial upregulation of mitochondrial TERT and sustenance during transverse aortic constriction (TAC)-induced cardiac hypertrophy. Overexpression of mitochondrial-targeted TERT (mito-TERT) via adeno-associated virus serotype 9 carrying the TERT-coding sequence fused with N-terminal mitochondrial-targeting sequence improved cardiac function and attenuated cardiac hypertrophy. Mechanistically, mito-TERT ameliorated mitochondrial dysfunction and oxidative stress, which were associated with improving the activity and subunit composition of complex I. Remarkably, the telomerase activator TA-65 also exhibited an antihypertrophic effect. Collectively, our results reveal a significant role for mito-TERT in mediating the antihypertrophic effect of physical exercise and demonstrate that TERT is a potential drug target for treating cardiac hypertrophy.

Cardioproteomics: Insights on Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain a global health challenge and are the leading cause of deaths worldwide. Proteomics has emerged as a valuable tool for unraveling the complex molecular mechanisms underlying CVDs, offering insights into biomarker discovery, drug targets, and personalized medicine. This review explores key breakthroughs in proteomic applications related to CVDs, mainly coronary artery disease (CAD), ischemic heart diseases such as myocardial infarction (MI), and cardiomyopathies. Notable findings include potential biomarkers, therapeutic targets, and insights into disease pathogenesis. The review highlights the importance of proteomics in advancing our understanding of CVDs and shaping future therapeutic approaches.

Plasma Proteomics to Identify Drug Targets for Ischemic Heart Disease

BACKGROUND

Integrated analyses of plasma proteomic and genetic markers in prospective studies can clarify the causal relevance of proteins and discover novel targets for ischemic heart disease (IHD) and other diseases.

OBJECTIVES

The purpose of this study was to examine associations of proteomics and genetics data with IHD in population studies to discover novel preventive treatments.

METHODS

We conducted a nested case-cohort study in the China Kadoorie Biobank (CKB) involving 1,971 incident IHD cases and 2,001 subcohort participants who were genotyped and free of prior cardiovascular disease. We measured 1,463 proteins in the stored baseline samples using the OLINK EXPLORE panel. Cox regression yielded adjusted HRs for IHD associated with individual proteins after accounting for multiple testing. Moreover, cis-protein quantitative loci (pQTLs) identified for proteins in genome-wide association studies of CKB and of UK Biobank were used as instrumental variables in separate 2-sample Mendelian randomization (MR) studies involving global CARDIOGRAM+C4D consortium (210,842 IHD cases and 1,378,170 controls).

RESULTS

Overall 361 proteins were significantly associated at false discovery rate <0.05 with risk of IHD (349 positively, 12 inversely) in CKB, including N-terminal prohormone of brain natriuretic peptide and proprotein convertase subtilisin/kexin type 9. Of these 361 proteins, 212 had cis-pQTLs in CKB, and MR analyses of 198 variants in CARDIOGRAM+C4D identified 13 proteins that showed potentially causal associations with IHD. Independent MR analyses of 307 cis-pQTLs identified in Europeans replicated associations for 4 proteins (FURIN, proteinase-activated receptor-1, Asialoglycoprotein receptor-1, and matrix metalloproteinase-3). Further downstream analyses showed that FURIN, which is highly expressed in endothelial cells, is a potential novel target and matrix metalloproteinase-3 a potential repurposing target for IHD.

CONCLUSIONS

Integrated analyses of proteomic and genetic data in Chinese and European adults provided causal support for FURIN and multiple other proteins as potential novel drug targets for treatment of IHD.

Discovery of age-related early-stage glycated proteins based on deep quantitative serum glycated proteome analysis

Aging is a pressing global health issue that is linked to various diseases, such as diabetes and Alzheimer's disease. It is well known that glycation plays a pathological role in the aging process and age-related diseases. Thus, it is of great significance to discover protein glycation at an early stage for monitoring and intervention in the aging process. However, the endogenous age-related early-stage glycated proteome remains insufficiently profiled. To address this research gap, our study focuses on assessing glycated proteomics profiles in the serum of mice. We employ a robust and quantitative strategy previously developed by our team, to analyze endogenous glycated proteome in serum samples of 4 age groups of mice (10 weeks, 16 weeks, 48 weeks and 80 weeks). In total, 2959 endogenous glycated peptides corresponding to 296 serum proteins are identified from 48 runs of serum samples from 16 mice across the four age groups. By comparing these glycated peptides between adjacent age groups, we discover 49 glycated peptides from 35 proteins that show significant upregulation between the 48-week and 80-week age groups. Furthermore, we identify 10 glycated proteins (or protein groups) that are significantly upregulated only between the 48-week and 80-week age groups, including lecithin-cholesterol acyltransferase (LCAT) and apolipoprotein A-II (Apo A-II). These novel findings provide unique signatures for understanding the aging process and age-related diseases. By shedding light on the early-stage glycated proteome, our study contributes valuable insights that may have implications for future interventions and therapeutic approaches.

Aging Biomarker Consortium, Zhang W, Che Y, Tang X, Chen S, Song M, Wang L, Sun AJ, Chen HZ, Xu M, Wang M, Pu J, Li Z, Xiao J, Cao CM, Zhang Y, Lu Y, Zhao Y, Wang YJ, Zhang C, Shen T, Zhang W, Tao L, Qu J, Tang YD, Liu GH, Pei G, Li J, Cao F. A biomarker framework for cardiac aging: the Aging Biomarker Consortium consensus statement

Cardiac aging constitutes a significant risk factor for cardiovascular diseases prevalent among the elderly population. Urgent attention is required to prioritize preventive and management strategies for age-related cardiovascular conditions to safeguard the well-being of elderly individuals. In response to this critical challenge, the Aging Biomarker Consortium (ABC) of China has formulated an expert consensus on cardiac aging biomarkers. This consensus draws upon the latest scientific literature and clinical expertise to provide a comprehensive assessment of biomarkers associated with cardiac aging. Furthermore, it presents a standardized methodology for characterizing biomarkers across three dimensions: functional, structural, and humoral. The functional dimension encompasses a broad spectrum of markers that reflect diastolic and systolic functions, sinus node pacing, neuroendocrine secretion, coronary microcirculation, and cardiac metabolism. The structural domain emphasizes imaging markers relevant to concentric cardiac remodeling, coronary artery calcification, and epicardial fat deposition. The humoral aspect underscores various systemic (N) and heart-specific (X) markers, including endocrine hormones, cytokines, and other plasma metabolites. The ABC's primary objective is to establish a robust foundation for assessing cardiac aging, thereby furnishing a dependable reference for clinical applications and future research endeavors. This aims to contribute significantly to the enhancement of cardiovascular health and overall well-being among elderly individuals.

Features characterising cardiac autonomic neuropathy in diabetes using ensembled classification

OBJECTIVE

Using supervised machine learning to classify the severity of cardiovascular autonomic neuropathy (CAN). The aims were 1) to investigate which features contribute to characterising CAN 2) to generate an ensembled set of features that best describes the variation in CAN classification.

METHODS

Eighty-two features from demographic, beat-to-beat, biochemical, and inflammation were obtained from 204 people with diabetes and used in three machine-learning-classifiers, these are: support vector machine, decision tree, and random forest. All data were ensembled using a weighted mean of the features from each classifier.

RESULTS

The 10 most important features derived from the domains: Beat-to-beat, inflammation markers, disease-duration, and age.

CONCLUSIONS

Beat-to-beat measures associate with CAN as diagnosis is mainly based on cardiac reflex responses, disease-duration and age are also related to CAN development throughout disease progression. The inflammation markers may reflect the underlying disease process, and therefore, new treatment modalities targeting systemic low-grade inflammation should potentially be tested to prevent the development of CAN.

SIGNIFICANCE

Cardiac reflex responses should be monitored closely to diagnose and classify severity levels of CAN accurately. Standard clinical biochemical analytes, such as glycaemic level, lipidic level, or kidney function were not included in the ten most important features. Beat-to-beat measures accounted for approximately 60% of the features in the ensembled data.

CCL17/TARC in autoimmunity and inflammation-not just a T-cell chemokine

Chemokine (C-C) ligand 17 (CCL17) was first identified as thymus- and activation-regulated chemokine when it was found to be constitutively expressed in the thymus and identified as a T-cell chemokine. This chemoattractant molecule has subsequently been found at elevated levels in a range of autoimmune and inflammatory diseases, as well as in cancer. CCL17 is a C-C chemokine receptor type 4 (CCR4) ligand, with chemokine (C-C) ligand 22 being the other major ligand and, as CCR4 is highly expressed on helper T cells, CCL17 can play a role in T-cell-driven diseases, usually considered to be via its chemotactic activity on T helper 2 cells; however, given that CCR4 is also expressed by other cell types and there is elevated expression of CCL17 in many diseases, a broader CCL17 biology is suggested. In this review, we summarize the biology of CCL17, its regulation and its potential contribution to the pathogenesis of various preclinical models. Reference is made, for example, to recent literature indicating a role for CCL17 in the control of pain as part of a granulocyte macrophage-colony-stimulating factor/CCL17 pathway in lymphocyte-independent models and thus not as a T-cell chemokine. The review also discusses the potential for CCL17 to be a biomarker and a therapeutic target in human disorders.

The application of Aptamer in biomarker discovery

Biomarkers are detectable molecules that can reflect specific physiological states of cells, organs, and organisms and therefore be regarded as indicators for specific diseases. And the discovery of biomarkers plays an essential role in cancer management from the initial diagnosis to the final treatment regime. Practically, reliable clinical biomarkers are still limited, restricted by the suboptimal methods in biomarker discovery. Nucleic acid aptamers nowadays could be used as a powerful tool in the discovery of protein biomarkers. Nucleic acid aptamers are single-strand oligonucleotides that can specifically bind to various targets with high affinity. As artificial ssDNA or RNA, aptamers possess unique advantages compared to conventional antibodies. They can be flexible in design, low immunogenicity, relative chemical/thermos stability, as well as modifying convenience. Several SELEX (Systematic Evolution of Ligands by Exponential Enrichment) based methods have been generated recently to construct aptamers for discovering new biomarkers in different cell locations. Secretome SELEX-based aptamers selection can facilitate the identification of secreted protein biomarkers. The aptamers developed by cell-SELEX can be used to unveil those biomarkers presented on the cell surface. The aptamers from tissue-SELEX could target intracellular biomarkers. And as a multiplexed protein biomarker detection technology, aptamer-based SOMAScan can analyze thousands of proteins in a single run. In this review, we will introduce the principle and workflow of variations of SELEX-based methods, including secretome SELEX, ADAPT, Cell-SELEX and tissue SELEX. Another powerful proteome analyzing tool, SOMAScan, will also be covered. In the second half of this review, how these methods accelerate biomarker discovery in various diseases, including cardiovascular diseases, cancer and neurodegenerative diseases, will be discussed.

The Role of the Piezo1 Mechanosensitive Channel in Heart Failure

Mechanotransduction (MT) is inseparable from the pathobiology of heart failure (HF). However, the effects of mechanical forces on HF remain unclear. This review briefly describes how Piezo1 functions in HF-affected cells, including endothelial cells (ECs), cardiac fibroblasts (CFs), cardiomyocytes (CMs), and immune cells. Piezo1 is a mechanosensitive ion channel that has been extensively studied in recent years. Piezo1 responds to different mechanical forces and converts them into intracellular signals. The pathways that modulate the Piezo1 switch have also been briefly described. Experimental drugs that specifically activate Piezo1-like proteins, such as Yoda1, Jedi1, and Jedi2, are available for clinical studies to treat Piezo1-related diseases. The only mechanosensitive ion-channel-specific inhibitor available is GsMTx4, which can turn off Piezo1 by modulating the local membrane tension. Ultrasound waves can modulate Piezo1 switching in vitro with the assistance of microbubbles. This review provides new possible targets for heart failure therapy by exploring the cellular functions of Piezo1 that are involved in the progression of the disease. Modulation of Piezo1 activity may, therefore, effectively delay the progression of heart failure.

Sirtuin 2 deficiency aggravates ageing-induced vascular remodelling in humans and mice

AIMS

The mechanisms underlying ageing-induced vascular remodelling remain unclear. This study investigates the role and underlying mechanisms of the cytoplasmic deacetylase sirtuin 2 (SIRT2) in ageing-induced vascular remodelling.

METHODS AND RESULTS

Transcriptome and quantitative real-time PCR data were used to analyse sirtuin expression. Young and old wild-type and Sirt2 knockout mice were used to explore vascular function and pathological remodelling. RNA-seq, histochemical staining, and biochemical assays were used to evaluate the effects of Sirt2 knockout on the vascular transcriptome and pathological remodelling and explore the underlying biochemical mechanisms. Among the sirtuins, SIRT2 had the highest levels in human and mouse aortas. Sirtuin 2 activity was reduced in aged aortas, and loss of SIRT2 accelerated vascular ageing. In old mice, SIRT2 deficiency aggravated ageing-induced arterial stiffness and constriction-relaxation dysfunction, accompanied by aortic remodelling (thickened vascular medial layers, breakage of elastin fibres, collagen deposition, and inflammation). Transcriptome and biochemical analyses revealed that the ageing-controlling protein p66Shc and metabolism of mitochondrial reactive oxygen species (mROS) contributed to SIRT2 function in vascular ageing. Sirtuin 2 repressed p66Shc activation and mROS production by deacetylating p66Shc at lysine 81. Elimination of reactive oxygen species by MnTBAP repressed the SIRT2 deficiency-mediated aggravation of vascular remodelling and dysfunction in angiotensin II-challenged and aged mice. The SIRT2 coexpression module in aortas was reduced with ageing across species and was a significant predictor of age-related aortic diseases in humans.

CONCLUSION

The deacetylase SIRT2 is a response to ageing that delays vascular ageing, and the cytoplasm-mitochondria axis (SIRT2-p66Shc-mROS) is important for vascular ageing. Therefore, SIRT2 may serve as a potential therapeutic target for vascular rejuvenation.

Biomarkers of aging

Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant.

Thymus transplantation regulates blood pressure and alleviates hypertension-associated heart and kidney damage via transcription factors FoxN1 pathway

Previous studies have found that thymus is involved in the process of hypertension. However, whether thymus transplantation alleviates target organ damage in hypertensive mice remains unknown. The aim of this study was to evaluate the effects of thymus transplantation on blood pressure and target organ changes in mice with hypertension. Mice were randomly divided into normal control group (Con), hypertensive group (HTN) and thymus transplantation group (HTN + Trans). Thymus of neonatal mice was transplanted into the renal capsule of the transplantation group. After transplantation, the mouse tail noninvasive pressure was measured and heart function was evaluated weekly. Then mice were euthanized and organs or tissues were harvested at 4 weeks post-transplantation. The blood pressure of HTN + Trans group was lower than that in the HTN group. The expression of FoxN1, Aire, ATRAP, thymosin β4 and the content of sjTREC in thymus of HTN group was decreased and the number of naïve T cells in HTN group was lower compared with other two groups. The ratio of cTEC/mTEC in HTN group was higher than that in Con group and lower than that in HTN + Trans group. Cardiac pathology showed cardiac hypertrophy and fibrosis in HTN group whereas thymus transplantation improved heart function and structure. Altogether, our findings demonstrated thymus transplantation could improve thymus function of hypertensive mice, which increased the expression of thymus transcription factor FoxN1, affected the proportion of T cell subsets, and increased thymosin β4 thereby reducing blood pressure and reversing the progression of target organ damage.

CCL17 and CCL22 chemokines are upregulated in human obesity and play a role in vascular dysfunction

Background/Aims

Chemokines are known to play critical roles mediating inflammation in many pathophysiological processes. The aim of this study was to investigate the role of chemokine receptor CCR4 and its ligands CCL17 and CCL22 in human morbid obesity.

Methods

Circulating levels of CCL17 and CCL22 were measured in 60 morbidly obese patients (mean age, 45 ± 1 years; body mass index/BMI, 44 ± 1 kg/m²) who had undergone bariatric bypass surgery, and 20 control subjects. Paired subcutaneous (SCAT) and visceral adipose tissue (VCAT) from patients were analysed to measure expression of CCR4 and its ligands by RT-PCR, western blot and immunohistochemical analysis. The effects of CCR4 neutralization ex vivo on leukocyte-endothelial cells were also evaluated.

Results

Compared with controls, morbidly obese patients presented higher circulating levels of CCL17 (p=0.029) and CCL22 (p<0.001) and this increase was positively correlated with BMI (p=0.013 and p=0.0016), and HOMA-IR Index (p=0.042 and p< 0.001). Upregulation of CCR4, CCL17 and CCL22 expression was detected in VCAT in comparison with SCAT (p<0.05). Using the parallel-plate flow chamber model, blockade of endothelial CCR4 function with the neutralizing antibody anti-CCR4 in morbidly obese patients significantly reduced leucocyte adhesiveness to dysfunctional endothelium, a key event in atherogenesis. Additionally, CCL17 and CCL22 increased activation of the ERK1/2 mitogen-activated protein kinase signalling pathway in human aortic endothelial cells, which was significantly reduced by CCR4 inhibition (p=0.016 and p<0.05).

Conclusion

Based on these findings, pharmacological modulation of the CCR4 axis could represent a new therapeutic approach to prevent adipose tissue dysfunction in obesity.