Role of CCR2 in the Development of Streptozotocin-Treated Diabetic Cardiomyopathy

The cytoplasmic sensor, the AIM2 inflammasome: A precise therapeutic target in vascular and metabolic diseases

Cardio-cerebrovascular diseases encompass pathological changes in the heart, brain and vascular system, which pose a great threat to health and well-being worldwide. Moreover, metabolic diseases contribute to and exacerbate the impact of vascular diseases. Inflammation is a complex process that protects against noxious stimuli but is also dysregulated in numerous so-called inflammatory diseases, one of which is atherosclerosis. Inflammation involves multiple organ systems and a complex cascade of molecular and cellular events. Numerous studies have shown that inflammation plays a vital role in cardio-cerebrovascular diseases and metabolic diseases. The absent in melanoma 2 (AIM2) inflammasome detects and is subsequently activated by double-stranded DNA in damaged cells and pathogens. With the assistance of the mature effector molecule caspase-1, the AIM2 inflammasome performs crucial biological functions that underpin its involvement in cardio-cerebrovascular diseases and related metabolic diseases: The production of interleukin-1 beta (IL-1β), interleukin-18 (IL-18) and N-terminal pore-forming Gasdermin D fragment (GSDMD-N) mediates a series of inflammatory responses and programmed cell death (pyroptosis and PANoptosis). Currently, several agents have been reported to inhibit the activity of the AIM2 inflammasome and have the potential to be evaluated for use in clinical settings. In this review, we systemically elucidate the assembly, biological functions, regulation and mechanisms of the AIM2 inflammasome in cardio-cerebrovascular diseases and related metabolic diseases and outline the inhibitory agents of the AIM2 inflammasome as potential therapeutic drugs.

The role and therapeutic potential of macrophages in the pathogenesis of diabetic cardiomyopathy

This review provides a comprehensive analysis of the critical role played by macrophages and their underlying mechanisms in the progression of diabetic cardiomyopathy (DCM). It begins by discussing the origins and diverse subtypes of macrophages, elucidating their spatial distribution and modes of intercellular communication, thereby emphasizing their significance in the pathogenesis of DCM. The review then delves into the intricate relationship between macrophages and the onset of DCM, particularly focusing on the epigenetic regulatory mechanisms employed by macrophages in the context of DCM condition. Additionally, the review discusses various therapeutic strategies aimed at targeting macrophages to manage DCM. It specifically highlights the potential of natural food components in alleviating diabetic microvascular complications and examines the modulatory effects of existing hypoglycemic drugs on macrophage activity. These findings, summarized in this review, not only provide fresh insights into the role of macrophages in diabetic microvascular complications but also offer valuable guidance for future therapeutic research and interventions in this field.

Adipocyte-Specific Hnrnpa1 Knockout Aggravates Obesity-Induced Metabolic Dysfunction via Upregulation of CCL2

Heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) is involved in lipid and glucose metabolism via mRNA processing. However, whether and how HNRNPA1 alters adipocyte function in obesity remain obscure. Here, we found that the obese state downregulated HNRNPA1 expression in white adipose tissue (WAT). The depletion of adipocyte HNRNPA1 promoted markedly increased macrophage infiltration and expression of proinflammatory and fibrosis genes in WAT of obese mice, eventually leading to exacerbated insulin sensitivity, glucose tolerance, and hepatic steatosis. Mechanistically, HNRNPA1 interacted with Ccl2 and regulated its mRNA stability. Intraperitoneal injection of CCL2-CCR2 signaling antagonist improved adipose tissue inflammation and systemic glucose homeostasis. Furthermore, HNRNPA1 expression in human WAT was negatively correlated with BMI, fat percentage, and subcutaneous fat area. Among individuals with 1-year metabolic surgery follow-up, HNRNPA1 expression was positively related to percentage of total weight loss. These findings identify adipocyte HNRNPA1 as a link between adipose tissue inflammation and systemic metabolic homeostasis, which might be a promising therapeutic target for obesity-related disorders.

ARTICLE HIGHLIGHTS

Gene expression of Postn and FGF7 in canine chordae tendineae and their effects on flexor tenocyte biology

Chordae tendineae, referred to as heart tendinous cords, act as tendons connecting the papillary muscles to the valves in the heart. Their role is analogous to tendons in the musculoskeletal system. Despite being exposed to millions of cyclic tensile stretches over a human's lifetime, chordae tendineae rarely suffer from overuse injuries. On the other hand, musculoskeletal tendinopathy is very common and remains challenging in clinical treatment. The objective of this study was to investigate the mechanism behind the remarkable durability and resistance to overuse injuries of chordae tendineae, as well as to explore their effects on flexor tenocyte biology. The messenger RNA expression profiles of chordae tendineae were analyzed using RNA sequencing and verified by quantitative reverse transcription polymerase chain reaction  and immunohistochemistry. Interestingly, we found that periostin (Postn) and fibroblast growth factor 7 (FGF7) were expressed at significantly higher levels in chordae tendineae, compared to flexor tendons. We further treated flexor tenocytes in vitro with periostin and FGF7 to examine their effects on the proliferation, migration, apoptosis, and tendon-related gene expression of flexor tenocytes. The results displayed enhanced cell proliferation ability at an early stage and an antiapoptotic effect on tenocytes, while treated with periostin and/or FGF7 proteins. Furthermore, there was a trend of promoted tenocyte migration capability. These findings indicated that Postn and FGF7 may represent novel cytokines to target flexor tendon healing. Clinical significance: The preliminary discovery leads to a novel idea for treating tendinopathy in the musculoskeletal system using specific molecules identified from chordae tendineae.

Irisin attenuates type 1 diabetic cardiomyopathy by anti-ferroptosis via SIRT1-mediated deacetylation of p53

BACKGROUND

Diabetic cardiomyopathy (DCM) is a serious complication in patients with type 1 diabetes mellitus (T1DM), which still lacks adequate therapy. Irisin, a cleavage peptide off fibronectin type III domain-containing 5, has been shown to preserve cardiac function in cardiac ischemia-reperfusion injury. Whether or not irisin plays a cardioprotective role in DCM is not known.

METHODS AND RESULTS

T1DM was induced by multiple low-dose intraperitoneal injections of streptozotocin (STZ). Our current study showed that irisin expression/level was lower in the heart and serum of mice with STZ-induced TIDM. Irisin supplementation by intraperitoneal injection improved the impaired cardiac function in mice with DCM, which was ascribed to the inhibition of ferroptosis, because the increased ferroptosis, associated with increased cardiac malondialdehyde (MDA), decreased reduced glutathione (GSH) and protein expressions of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), was ameliorated by irisin. In the presence of erastin, a ferroptosis inducer, the irisin-mediated protective effects were blocked. Mechanistically, irisin treatment increased Sirtuin 1 (SIRT1) and decreased p53 K382 acetylation, which decreased p53 protein expression by increasing its degradation, consequently upregulated SLC7A11 and GPX4 expressions. Thus, irisin-mediated reduction in p53 decreases ferroptosis and protects cardiomyocytes against injury due to high glucose.

CONCLUSION

This study demonstrated that irisin could improve cardiac function by suppressing ferroptosis in T1DM via the SIRT1-p53-SLC7A11/GPX4 pathway. Irisin may be a therapeutic approach in the management of T1DM-induced cardiomyopathy.

Inflammation in diabetes complications: molecular mechanisms and therapeutic interventions

At present, diabetes mellitus (DM) has been one of the most endangering healthy diseases. Current therapies contain controlling high blood sugar, reducing risk factors like obesity, hypertension, and so on; however, DM patients inevitably and eventually progress into different types of diabetes complications, resulting in poor quality of life. Unfortunately, the clear etiology and pathogenesis of diabetes complications have not been elucidated owing to intricate whole-body systems. The immune system was responsible to regulate homeostasis by triggering or resolving inflammatory response, indicating it may be necessary to diabetes complications. In fact, previous studies have been shown inflammation plays multifunctional roles in the pathogenesis of diabetes complications and is attracting attention to be the meaningful therapeutic strategy. To this end, this review systematically concluded the current studies over the relationships of susceptible diabetes complications (e.g., diabetic cardiomyopathy, diabetic retinopathy, diabetic peripheral neuropathy, and diabetic nephropathy) and inflammation, ranging from immune cell response, cytokines interaction to pathomechanism of organ injury. Besides, we also summarized various therapeutic strategies to improve diabetes complications by target inflammation from special remedies to conventional lifestyle changes. This review will offer a panoramic insight into the mechanisms of diabetes complications from an inflammatory perspective and also discuss contemporary clinical interventions.

USP28 Serves as a Key Suppressor of Mitochondrial Morphofunctional Defects and Cardiac Dysfunction in the Diabetic Heart

BACKGROUND

The majority of people with diabetes are susceptible to cardiac dysfunction and heart failure, and conventional drug therapy cannot correct diabetic cardiomyopathy progression. Herein, we assessed the potential role and therapeutic value of USP28 (ubiquitin-specific protease 28) on the metabolic vulnerability of diabetic cardiomyopathy.

METHODS

The type 2 diabetes mouse model was established using db/db leptin receptor-deficient mice and high-fat diet/streptozotocin-induced mice. Cardiac-specific knockout of USP28 in the db/db background mice was generated by crossbreeding db/m and Myh6-Cre+/USP28fl/fl mice. Recombinant adeno-associated virus serotype 9 carrying USP28 under cardiac troponin T promoter was injected into db/db mice. High glucose plus palmitic acid-incubated neonatal rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes were used to imitate diabetic cardiomyopathy in vitro. The molecular mechanism was explored through RNA sequencing, immunoprecipitation and mass spectrometry analysis, protein pull-down, chromatin immunoprecipitation sequencing, and chromatin immunoprecipitation assay.

RESULTS

Microarray profiling of the UPS (ubiquitin-proteasome system) on the basis of db/db mouse hearts and diabetic patients' hearts demonstrated that the diabetic ventricle presented a significant reduction in USP28 expression. Diabetic Myh6-Cre+/USP28fl/fl mice exhibited more severe progressive cardiac dysfunction, lipid accumulation, and mitochondrial disarrangement, compared with their controls. On the other hand, USP28 overexpression improved systolic and diastolic dysfunction and ameliorated cardiac hypertrophy and fibrosis in the diabetic heart. Adeno-associated virus serotype 9-USP28 diabetic mice also exhibited less lipid storage, reduced reactive oxygen species formation, and mitochondrial impairment in heart tissues than adeno-associated virus serotype 9-null diabetic mice. As a result, USP28 overexpression attenuated cardiac remodeling and dysfunction, lipid accumulation, and mitochondrial impairment in high-fat diet/streptozotocin-induced type 2 diabetes mice. These results were also confirmed in neonatal rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes. RNA sequencing, immunoprecipitation and mass spectrometry analysis, chromatin immunoprecipitation assays, chromatin immunoprecipitation sequencing, and protein pull-down assay mechanistically revealed that USP28 directly interacted with PPARα (peroxisome proliferator-activated receptor α), deubiquitinating and stabilizing PPARα (Lys152) to promote Mfn2 (mitofusin 2) transcription, thereby impeding mitochondrial morphofunctional defects. However, such cardioprotective benefits of USP28 were largely abrogated in db/db mice with PPARα deletion and conditional loss-of-function of Mfn2.

CONCLUSIONS

Our findings provide a USP28-modulated mitochondria homeostasis mechanism that involves the PPARα-Mfn2 axis in diabetic hearts, suggesting that USP28 activation or adeno-associated virus therapy targeting USP28 represents a potential therapeutic strategy for diabetic cardiomyopathy.

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

Advances of nanotechnology for intracerebral hemorrhage therapy

Intracerebral hemorrhage (ICH), the most devastating subtype of stoke, is of high mortality at 5 years and even those survivors usually would suffer permanent disabilities. Fortunately, various preclinical active drugs have been approached in ICH, meanwhile, the therapeutic effects of these pharmaceutical ingredients could be fully boosted with the assistance of nanotechnology. In this review, besides the pathology of ICH, some ICH therapeutically available active drugs and their employed nanotechnologies, material functions, and therapeutic principles were comprehensively discussed hoping to provide novel and efficient strategies for ICH therapy in the future.

SIRT6: A potential therapeutic target for diabetic cardiomyopathy

The abnormal lipid metabolism in diabetic cardiomyopathy can cause myocardial mitochondrial dysfunction, lipotoxicity, abnormal death of myocardial cells, and myocardial remodeling. Mitochondrial homeostasis and normal lipid metabolism can effectively slow down the development of diabetic cardiomyopathy. Recent studies have shown that SIRT6 may play an important role in the pathological changes of diabetic cardiomyopathy such as myocardial cell death, myocardial hypertrophy, and myocardial fibrosis by regulating mitochondrial oxidative stress and glucose and lipid metabolism. Therefore, understanding the function of SIRT6 and its role in the pathogenesis of diabetic cardiomyopathy is of great significance for exploring and developing new targets and drugs for the treatment of diabetic cardiomyopathy. This article reviews the latest findings of SIRT6 in the pathogenesis of diabetic cardiomyopathy, focusing on the regulation of mitochondria and lipid metabolism by SIRT6 to explore potential clinical treatments.

Blood Immune Cell Alterations in Patients with Hypertensive Left Ventricular Hypertrophy and Heart Failure with Preserved Ejection Fraction

(1) Background: Chronic inflammation and fibrosis are key players in cardiac remodeling associated with left ventricular hypertrophy (LVH) and heart failure with a preserved ejection fraction (HFpEF). Monocytes and T-helpers (Th) are involved in both pro-inflammatory and fibrotic processes, while regulatory T-cells (Treg) could be considered to suppress chronic inflammation in the hypertrophied myocardium. We aimed to estimate the relationship between the frequencies of circulating CD4⁺ T-cell and monocyte subpopulations and the variables of left ventricular (LV) diastolic function in patients with LVH depending on the presence of HFpEF. (2) Methods: We enrolled 57 patients with asymptomatic hypertensive LVH (n = 21), or LVH associated with HFpEF (n = 36). A clinical assessment and echocardiographs were analyzed. CD4⁺ Treg, activated Th (Th-act), and monocyte (classical, intermediate, and non-classical) subpopulations were evaluated via direct immunofluorescence and flow cytometry. (3) Results: Patients with HFpEF had a lower Treg/Th-act ratio (p = 0.001). Though asymptomatic patients and patients with HFpEF were comparable in terms of both the total monocyte number and monocyte subsets, there were moderate correlations between intermediate monocyte count and conventional and novel echocardiographic variables of LV diastolic dysfunction in patients with HFpEF. (4) Conclusions: In patients with LVH, the clinical deterioration (transition to HFpEF) and progression of LV diastolic dysfunction are probably associated with T-cell disbalance and an increase in intermediate monocyte counts.

LncRNA ZNF593-AS alleviates diabetic cardiomyopathy via suppressing IRF3 signaling pathway

Diabetes could directly induce cardiac injury, leading to cardiomyopathy. However, treatment strategies for diabetic cardiomyopathy remain limited. ZNF593-AS knockout and cardiomyocyte-specific transgenic mice were constructed. In addition, high-fat diet (HFD)-induced diabetic mouse model and db/db mice, another classic diabetic mouse model, were employed. ZNF593-AS was silenced using GapmeR, a modified antisense oligonucleotide, while overexpressed using a recombinant adeno-associated virus serotype 9-mediated gene delivery system. Transcriptome sequencing, RNA pull-down assays, and RNA immunoprecipitation assays were also performed to investigate the underlying mechanisms. ZNF593-AS expression was decreased in diabetic hearts. ZNF593-AS attenuated the palmitic acid-induced apoptosis of cardiomyocytes in vitro. In HFD-induced diabetic mice, ZNF593-AS deletion aggravated cardiac dysfunction and enhanced cardiac apoptosis and inflammation. In contrast, HFD-induced cardiac dysfunction was improved in ZNF593-AS transgenic mice. Consistently, ZNF593-AS exerted the same cardioprotective effects in db/db mice. Mechanistically, ZNF593-AS directly interacted with the functional domain of interferon regulatory factor 3 (IRF3), and suppressed fatty acid-induced phosphorylation and activation of IRF3, contributing to the amelioration of cardiac cell death and inflammation. In conclusion, our results identified the protective role of ZNF593-AS in diabetic cardiomyopathy, suggesting a novel potential therapeutic target.

Inhibition of CCR2 attenuates neuroinflammation and neuronal apoptosis after subarachnoid hemorrhage through the PI3K/Akt pathway

BACKGROUND

Neuroinflammation and neuronal apoptosis are closely associated with a poor prognosis in patients with subarachnoid hemorrhage (SAH). We investigated the role of C-C motif chemokine receptor 2 (CCR2) in SAH.

METHODS

Pre-processed RNA-seq transcriptome datasets GSE167110 and GSE79416 from the Gene Expression Omnibus (GEO) database were screened for genes differentially expressed between mice with SAH and control mice, using bioinformatics analysis. The endovascular perforation model was performed to establish SAH. RS504393 (a CCR2 antagonist) and LY294002 (PI3K inhibitor) were administered to explore the mechanism of neuroinflammation after SAH. SAH grading, neurological scoring, brain water content and blood-brain barrier (BBB) permeability determination, enzyme-linked immunosorbent assay (ELISA), western blotting, and immunofluorescence were performed. An in vitro model of SAH was induced in H22 cells by hemin treatment. The protective mechanism of CCR2 inhibition was studied by adding RS504393 and LY294002. Clinical cerebrospinal fluid (CST) samples were detected by ELISA.

RESULTS

Expression of CCR2 was upregulated in both datasets and was identified as a hub gene. CCR2 expression was significantly upregulated in the cytoplasm of neurons after SAH, both in vitro and in vivo. RS significantly reduced the brain water content and blood-brain barrier permeability, alleviated neuroinflammation, and reduced neuronal apoptosis after SAH. Additionally, the protective effects of CCR2 inhibition were abolished by LY treatment. Finally, the levels of CCR2, inflammatory factors, and apoptotic factors were elevated in the CSF of patients with SAH. CCR2 levels were associated with patient outcomes at the 6-month follow-up.

CONCLUSION

CCR2 expression was upregulated in both in vitro and in vivo SAH models. Additionally, inhibition of CCR2, at least partly through the PI3K/AKT pathway, alleviated neuroinflammation and neuronal apoptosis in vivo and in vitro. CCR2 levels in the CSF have a moderate diagnostic value for 6-month outcome prediction in patients with SAH.

Activin receptor-like kinase 7 silencing alleviates cardiomyocyte apoptosis, cardiac fibrosis, and dysfunction in diabetic rats

Activin receptor-like kinase 7 (ALK7) is associated with lipometabolism and insulin sensitivity. Our previous study demonstrated that ALK7 participated in high glucose-induced cardiomyocyte apoptosis. The aim of our study was to investigate whether ALK7 plays an important role in modulating diabetic cardiomyopathy (DCM) and the mechanisms involved. The model of diabetes was induced in male Sprague-Dawley rats (120-140 g) by high-fat diet and intraperitoneal injections of low-dose streptozotocin (30 mg/kg). Animals were separated into four groups: control, DCM, DCM with ALK7 silencing, and DCM with vehicle control. The cardiac function was assessed by catheterization. Histopathologic analyses of collagen content and apoptosis rate, and protein analyses of ALK7, Smad2/3, Akt, Caspase3, and Bax/Bcl2 were performed. This study showed a rat model of DCM with hyperglycemia, severe insulin resistance, left ventricular dysfunction, and structural remodeling. With ALK7 silencing, the apoptotic cell death (apoptosis rate assessed by TUNEL, ratio of Bax/Bcl2 and expression of cleaved Caspase3), fibrosis areas, and Collagen I-to-III ratio decreased significantly. The insulin resistance and diastolic dysfunction were also ameliorated by ALK7 silencing. Furthermore, the depressed phosphorylation of Akt was restored while elevated phosphorylation of Smad2/3 decreased after the silencing of ALK7. The results suggest ALK7 silencing plays a protective role in DCM and may serve as a potential target for the treatment of human DCM.

Role of CCR2-Positive Macrophages in Pathological Ventricular Remodelling

Even with recent advances in care, heart failure remains a major cause of morbidity and mortality, which urgently needs new treatments. One of the major antecedents of heart failure is pathological ventricular remodelling, the abnormal change in the size, shape, function or composition of the cardiac ventricles in response to load or injury. Accumulating immune cell subpopulations contribute to the change in cardiac cellular composition that occurs during ventricular remodelling, and these immune cells can facilitate heart failure development. Among cardiac immune cell subpopulations, macrophages that are recognized by their transcriptional or cell-surface expression of the chemokine receptor C-C chemokine receptor type 2 (CCR2), have emerged as playing an especially important role in adverse remodelling. Here, we assimilate the literature that has been generated over the past two decades describing the pathological roles that CCR2⁺ macrophages play in ventricular remodelling. The goal is to facilitate research and innovation efforts in heart failure therapeutics by drawing attention to the importance of studying the manner by which CCR2⁺ macrophages mediate their deleterious effects.

Estrogen receptor α mediated M1/M2 macrophages polarization plays a critical role in NASH of female mice

Owing to lacking protective effect of estrogen, OVX mice have higher risk of non-alcoholic fatty liver disease compared with normal female mice, when fed with high fat diet. Our study was to explore how estrogen protect against nonalcoholic steatohepatitis in female mice. We found that, lacking estrogen, M1 macrphages was activated and promoted steatohepatitis in obese OVX mice. And, ERα was responsible for estrogen to inhibit M1 macrphages activation and steatohepatitis. ERα knockdown aggravated M1 macrophages infiltration by transcriptionally upregulated its CCR2 expression. CCR2 antagonist effectively improved nonalcoholic steatohepatitis, ER stress and insulin resistance in ERα knockdown obese female mice. These results demonstrated ERα mediated M1 macrophages activation played a key role in nonalcoholic steatohepatitis.

Preliminary evidence for the presence of multiple forms of cell death in diabetes cardiomyopathy

Diabetic mellitus (DM) is a common degenerative chronic metabolic disease often accompanied by severe cardiovascular complications (DCCs) as major causes of death in diabetic patients with diabetic cardiomyopathy (DCM) as the most common DCC. The metabolic disturbance in DCM generates the conditions/substrates and inducers/triggers and activates the signaling molecules and death executioners leading to cardiomyocyte death which accelerates the development of DCM and the degeneration of DCM to heart failure. Various forms of programmed active cell death including apoptosis, pyroptosis, autophagic cell death, autosis, necroptosis, ferroptosis and entosis have been identified and characterized in many types of cardiac disease. Evidence has also been obtained for the presence of multiple forms of cell death in DCM. Most importantly, published animal experiments have demonstrated that suppression of cardiomyocyte death of any forms yields tremendous protective effects on DCM. Herein, we provide the most updated data on the subject of cell death in DCM, critical analysis of published results focusing on the pathophysiological roles of cell death, and pertinent perspectives of future studies.

Systematic analysis of myocardial immune progression in septic cardiomyopathy: Immune-related mechanisms in septic cardiomyopathy

Background

The immune infiltration and molecular mechanisms underlying septic cardiomyopathy (SC) have not been completely elucidated. This study aimed to identify key genes related to SC and elucidate the potential molecular mechanisms.

Methods

The weighted correlation network analysis (WGCNA), linear models for microarray analysis (LIMMA), protein-protein interaction (PPI) network, CIBERSORT, Kyoto Encyclopedia of Genes and Genomes pathway (KEGG), and gene set enrichment analysis (GSEA) were applied to assess the key pathway and hub genes involved in SC.

Results

We identified 10 hub genes, namely, LRG1, LCN2, PTX3, E LANE, TCN1, CLEC4D, FPR2, MCEMP1, CEACAM8, and CD177. Furthermore, we used GSEA for all genes and online tools to explore the function of the hub genes. Finally, we took the intersection between differential expression genes (DEGs) and hub genes to identify LCN2 and PTX3 as key genes. We found that immune-related pathways played vital roles in SC. LCN2 and PTX3 were key genes in SC progression, which mainly showed an anti-inflammatory effect. The significant immune cells in cardiomyocytes of SC were neutrophils and M2 macrophages.

Conclusion

These cells may have the potential to be prognostic and therapeutic targets in the clinical management of SC. Excessive anti-inflammatory function and neutrophil infiltration are probably the primary causes of SC.

Targeting Mediators of Inflammation in Heart Failure: A Short Synthesis of Experimental and Clinical Results

Inflammation has emerged as an important contributor to heart failure (HF) development and progression. Current research data highlight the diversity of immune cells, proteins, and signaling pathways involved in the pathogenesis and perpetuation of heart failure. Chronic inflammation is a major cardiovascular risk factor. Proinflammatory signaling molecules in HF initiate vicious cycles altering mitochondrial function and perturbing calcium homeostasis, therefore affecting myocardial contractility. Specific anti-inflammatory treatment represents a novel approach to prevent and slow HF progression. This review provides an update on the putative roles of inflammatory mediators involved in heart failure (tumor necrosis factor-alpha; interleukin 1, 6, 17, 18, 33) and currently available biological and non-biological therapy options targeting the aforementioned mediators and signaling pathways. We also highlight new treatment approaches based on the latest clinical and experimental research.

Regulation of the Immune Microenvironment by an NLRP3 Inhibitor Contributes to Attenuation of Acute Right Ventricular Failure in Rats with Pulmonary Arterial Hypertension

Background

Right heart failure is the terminal stage of PAH. When PAH patients suffer from pulmonary infection or puerperal infection heart failure often rapidly develops. Low dose of lipopolysaccharide induces rapid right ventricular failure in rats with pulmonary arterial hypertension.

Purpose

The objective of this study was to investigate whether the NLRP3 inflammasome mediates disturbance of the ventricular immune microenvironment of PAH rats and promotes right ventricular failure.

Methods

Intraperitoneal injection of monocrotaline was used to induce PAH in rats. Right ventricular function was measured via echocardiography before and after the rats were treated with lipopolysaccharide and MCC950. The degree of immune microenvironment disturbance in right ventricular tissue was measured with a rat chemokine and cytokine antibody array, Western blot, flow cytometry and quantitative real-time PCR analysis.

Results

After the rats were injected with LPS, they exhibited right ventricular dysfunction and a significant increase in right ventricular tissue inflammation with elevated M1 macrophage proportion. Administration of MCC950 suppressed inflammation and improved right ventricular function. The number of M1 macrophages was decreased after MCC950 treatment. NLRP3 inflammasome inhibition ameliorated LPS-induced changes in the immune microenvironment in the right heart and right ventricular dysfunction in rats with PAH.

Conclusion

Selective inhibition of NLRP3 pathway interfered the interaction between hypertrophic cardiomyocytes and macrophages in the initial stage of inflammation and maintained the immune microenvironment balance, eventually contributing to attenuation of LPS-induced acute heart failure in PAH rats.

CCR2 and PTPRC are regulators of tumor microenvironment and potential prognostic biomarkers of lung adenocarcinoma

Background

Tumor microenvironment (TME) plays an essential role in lung adenocarcinoma (LUAD) development and metastasis. With the development of TME research, it has been proved that differences in tumor-infiltrating immune cells (TICs) and gene expression profile are related to the prognosis of cancer. The aim of our study was to identify key genes affecting immune state in TME of LUAD.

Methods

The RNA-seq data and clinical characteristics of 594 LUAD patients were downloaded from the TCGA database. ImmuneScore, StromalScore and ESTIMATEScore of each LUAD sample were calculated using ESTIMATE algorithm. Based on the median of different scores, LUAD samples were divided into high and low score groups. Differentially expressed genes (DEGs) between groups were obtained, and univariate Cox regression analysis and protein-protein interaction (PPI) network were used to screen the shared DEGs generating in the intersection analysis. Finally, the CIBORSORT algorithm was performed to calculate the relative contents of TICs for each LUAD sample, and the correlation analysis between TICs and key genes was used to determine the influence of key genes to the TME.

Results

In the presented study, we found that three different scores were positively correlated with the prognosis of LUAD patients, and correlation analysis showed the different scores were closely related to tumor progression and metastasis. After performing the intersection analysis, a total of 585 up-regulated and 107 down-regulated DEGs between the high and low score groups were obtained, all of which were enriched in immune-related functions. Having used univariate COX regression analysis and PPI network, the key genes, CCR2 and PTPRC, affecting the immune status of TME and the prognosis of LUAD were acquired. Analysis based on the CIBERSORT algorithm suggested that CCR2 and PTPRC were correlated with a variety of TICs, and closely related to the clinical characteristics of the LUAD patients.

Conclusions

Our research showed that CCR2 and PTPRC may be potential prognostic markers in LUAD, which may affect the function of γδT cells and other immune cells by participating in the regulation of TME immune state.

FTZ Ameliorates Diabetic Cardiomyopathy by Inhibiting Inflammation and Cardiac Fibrosis in the Streptozotocin-Induced Model

Background

The pathogenesis and clinical features of diabetic cardiomyopathy (DCM) have been well studied in the past decade; however, effective approaches to prevent and treat this disease are limited. Fufang Zhenzhu Tiaozhi (FTZ) formula, a traditional Chinese prescription, is habitually used to treat dyslipidemia and diabetes. Recently, several studies have reported the therapeutic effects of FTZ on cardiovascular diseases. However, the effects of FTZ on DCM have not yet been fully elucidated. This study investigated the effects of FTZ on DCM and determined the mechanisms underlying its efficacy.

Methods

Diabetes was induced in mice by intraperitoneal injection of streptozotocin; the mice were randomly divided into a control group (Con), diabetes group (DCM), and diabetes-treated with FTZ (DCM + FTZ). Myocardial structural alterations, fibrosis biomarkers, and inflammation were observed. Besides, the potential targets and their related signaling pathways were analyzed using network pharmacology and further verified by Western blot.

Results

Diabetic mice showed significant body weight loss, hyperglycemia, and excessive collagen content in the cardiac tissue, while serum and myocardial inflammatory factors significantly increased. Nerveless, treatment with FTZ for 1 month significantly improved body weight, attenuated hyperglycemia, and alleviated diabetes-associated myocardial structure and function abnormalities. Furthermore, the serum levels of interleukin 12 (IL-12) and chemokine (C–C motif) ligand 2 (CCL2) as well as the mRNA levels of cardiac IL-12, IL-6, and C–C motif chemokine receptor 2 (Ccr2) reduced after FTZ treatment. Additionally, a total of 67 active compounds and 76 potential targets related to DCM were analyzed. Pathway and functional enrichment analyses showed that FTZ mainly regulates inflammation-related pathways, including MAPK and PI3K-AKT signaling pathways. Further investigation revealed that the activities of STAT3, AKT, and ERK were augmented in diabetic hearts but decreased in FTZ-treated cardiac tissues.

Conclusion

Our results suggest that FTZ exhibits therapeutic properties against DCM by ameliorating hyperglycemia-induced inflammation and fibrosis via at least partial inhibition of AKT, ERK, and STAT3 signaling pathways.

Fibrosis of the diabetic heart: Clinical significance, molecular mechanisms, and therapeutic opportunities

In patients with diabetes, myocardial fibrosis may contribute to the pathogenesis of heart failure and arrhythmogenesis, increasing ventricular stiffness and delaying conduction. Diabetic myocardial fibrosis involves effects of hyperglycemia, lipotoxicity and insulin resistance on cardiac fibroblasts, directly resulting in increased matrix secretion, and activation of paracrine signaling in cardiomyocytes, immune and vascular cells, that release fibroblast-activating mediators. Neurohumoral pathways, cytokines, growth factors, oxidative stress, advanced glycation end-products (AGEs), and matricellular proteins have been implicated in diabetic fibrosis; however, the molecular links between the metabolic perturbations and activation of a fibrogenic program remain poorly understood. Although existing therapies using glucose- and lipid-lowering agents and neurohumoral inhibition may act in part by attenuating myocardial collagen deposition, specific therapies targeting the fibrotic response are lacking. This review manuscript discusses the clinical significance, molecular mechanisms and cell biology of diabetic cardiac fibrosis and proposes therapeutic targets that may attenuate the fibrotic response, preventing heart failure progression.

The role of CCR2 in prognosis of patients with endometrial cancer and tumor microenvironment remodeling

Tumor microenvironment (TME) plays a core role in the genesis and progress of endometrial carcinoma (EC). The immune system, a crucial element of TME, functions in various immune cells. In this paper, we have tried to evaluate the prognosis in EC patients by the status of TME. The ESTIMATE algorithm was implemented to computer the number of immune and stromal components in EC tissues from the Cancer Genome Atlas dataset. The CIBERSORT algorithm was employed to assess the proportion of tumor-infiltrating immune cells in EC tissues, which were quantified as Stromal score and Immune score. After the construction of protein–protein interaction network, cell–cell chemokine receptor 2 (CCR2) was identified as a potential predictive element for EC. Further analysis indicated that a higher expression of CCR2 in EC patients was correlated with a better prognosis and a prolonged disease-free survival. According to the transcript level of CCR2, samples were separated into low- and high-expression groups. Gene Set Enrichment Analysis unveiled that metabolism-related pathways were mostly abundant in groups with high-expression, the other one was primarily correlated to immune-related activities. We figured out that some immune cells were positively related to CCR2, suggesting that CCR2 might serve as the immune-dominant status of TME, which was verified by qRT-PCR and HPA analysis in transcriptome and protein level, respectively. Also, CCR2 showed high correlation with immune modulators and chemokine signaling pathway. Thus, the level of CCR2 might have a prognostic value for EC patients, which provides a novel insight for therapeutic strategies of EC.

The Diabetic Cardiomyopathy: The Contributing Pathophysiological Mechanisms

Individuals with diabetes mellitus (DM) disclose a higher incidence and a poorer prognosis of heart failure (HF) than non-diabetic people, even in the absence of other HF risk factors. The adverse impact of diabetes on HF likely reflects an underlying “diabetic cardiomyopathy” (DM–CMP), which may by exacerbated by left ventricular hypertrophy and coronary artery disease (CAD). The pathogenesis of DM-CMP has been a hot topic of research since its first description and is still under active investigation, as a complex interplay among multiple mechanisms may play a role at systemic, myocardial, and cellular/molecular levels. Among these, metabolic abnormalities such as lipotoxicity and glucotoxicity, mitochondrial damage and dysfunction, oxidative stress, abnormal calcium signaling, inflammation, epigenetic factors, and others. These disturbances predispose the diabetic heart to extracellular remodeling and hypertrophy, thus leading to left ventricular diastolic and systolic dysfunction. This Review aims to outline the major pathophysiological changes and the underlying mechanisms leading to myocardial remodeling and cardiac functional derangement in DM-CMP.

Mechanisms and Therapeutic Prospects of Diabetic Cardiomyopathy Through the Inflammatory Response

The incidence of heart failure (HF) continues to increase rapidly in patients with diabetes. It is marked by myocardial remodeling, including fibrosis, hypertrophy, and cell death, leading to diastolic dysfunction with or without systolic dysfunction. Diabetic cardiomyopathy (DCM) is a distinct myocardial disease in the absence of coronary artery disease. DCM is partially induced by chronic systemic inflammation, underpinned by a hostile environment due to hyperglycemia, hyperlipidemia, hyperinsulinemia, and insulin resistance. The detrimental role of leukocytes, cytokines, and chemokines is evident in the diabetic heart, yet the precise role of inflammation as a cause or consequence of DCM remains incompletely understood. Here, we provide a concise review of the inflammatory signaling mechanisms contributing to the clinical complications of diabetes-associated HF. Overall, the impact of inflammation on the onset and development of DCM suggests the potential benefits of targeting inflammatory cascades to prevent DCM. This review is tailored to outline the known effects of the current anti-diabetic drugs, anti-inflammatory therapies, and natural compounds on inflammation, which mitigate HF progression in diabetic populations.

Effects of (Pro)renin Receptor on Diabetic Cardiomyopathy Pathological Processes in Rats via the PRR-AMPK-YAP Pathway

Diabetic cardiomyopathy (DCM) is a common complication associated with diabetes. The (pro)renin receptor (PRR) is an important member of the local tissue renin-angiotensin system and plays a vital role in many cardiovascular diseases. Yes-associated protein (YAP) also plays a crucial role in many cardiovascular diseases. However, the mechanism responsible for the effects of PRR and YAP on DCM remains unclear. The purpose of this study was to determine the role of PRR in the pathological progression of DCM and whether PRR influences the pathological processes of diabetic cardiomyopathy through YAP. We first established diabetic cardiomyopathy rats model, downregulated the expression of PRR, and upregulated and downregulated the expression of YAP. The levels of myocardial inflammation and fibrosis were then measured and cardiac function was evaluated. In vitro, primary rat cardiac fibroblasts (CFs) were cultured with high glucose, with or without transfection with recombinant adenovirus expressing PRR, and GSK621 was used to observe the effect of AMPK. The levels of inflammation and fibrosis were measured in vitro. The results showed that PRR and YAP silencing alleviated myocardial inflammation and fibrosis. GSK621 blocked the effect of PRR on AMPK and YAP and improved CF inflammation and fibrosis. The inhibition of PRR expression offers a new therapeutic strategy for the treatment of DCM. The effects of PRR on the pathological process of DCM in rats may be mediated via the PRR-AMPK-YAP pathway.

Expression of farnesyl pyrophosphate synthase is increased in diabetic cardiomyopathy

Farnesyl pyrophosphate synthase (FPPS)-catalyzed isoprenoid intermediates are involved in diabetic cardiomyopathy. This study investigated the specific role of FPPS in the development of diabetic cardiomyopathy. We demonstrated that FPPS expression was elevated in both in vivo and in vitro models of diabetic cardiomyopathy. FPPS inhibition decreased the expression of proteins related to cardiac fibrosis and cardiomyocytic hypertrophy, including collagen I, collagen III, connective tissue growth factor, natriuretic factor, brain natriuretic peptide, and β-myosin heavy chain. Furthermore, FPPS inhibition and knockdown prevented phosphorylated c-Jun N-terminal kinase 1/2 (JNK1/2) activation in vitro. In addition, a JNK1/2 inhibitor downregulated high-glucose-induced responses to diabetic cardiomyopathy. Finally, immunofluorescence revealed that cardiomyocytic size was elevated by high glucose and was decreased by zoledronate, small-interfering farnesyl pyrophosphate synthase (siFPPS), and a JNK1/2 inhibitor. Taken together, our findings indicate that FPPS and JNK1/2 may be part of a signaling pathway that plays an important role in diabetic cardiomyopathy.

Cardiac fibrosis

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

Chemokines in cardiac fibrosis

Several members of the chemokine family are involved in regulation of fibrosis. This review manuscript discusses the role of the chemokines in the pathogenesis of myocardial fibrosis. The CC chemokine CCL2 exerts fibrogenic actions through recruitment and activation of monocytes and macrophages expressing its receptor, CCR2. Other CC chemokines may also contribute to fibrotic remodeling by recruiting subsets of fibrogenic macrophages. CXC chemokines containing the ELR motif may exert pro-fibrotic actions, through recruitment of activated neutrophils and subsequent formation of neutrophil extracellular traps (NETs), or via activation of fibrogenic monocytes. CXCL12 has also been suggested to exert fibrogenic actions through effects on fibroblasts and immune cells. In contrast, the CXCR3 ligand CXCL10 was found to reduce cardiac fibrosis, inhibiting fibroblast migration. Chemokines are critical links between inflammation and fibrosis in myocardial disease and may be promising therapeutic targets for patients with heart failure accompanied by prominent inflammation and fibrosis.

Inflammatory Cytokines and Chemokines as Therapeutic Targets in Heart Failure

Heart failure exhibits remarkable pathophysiologic heterogeneity. A large body of evidence suggests that regardless of the underlying etiology, heart failure is associated with induction of cytokines and chemokines that may contribute to the pathogenesis of adverse remodeling, and systolic and diastolic dysfunction. The pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1, and IL-6 have been extensively implicated in the pathogenesis of heart failure. Inflammatory cytokines modulate phenotype and function of all myocardial cells, suppressing contractile function in cardiomyocytes, inducing inflammatory activation in macrophages, stimulating microvascular inflammation and dysfunction, and promoting a matrix-degrading phenotype in fibroblasts. Moreover, cytokine-induced growth factor synthesis may exert chronic fibrogenic actions contributing to the pathogenesis of heart failure with preserved ejection fraction (HFpEF). In addition to their role in adverse cardiac remodeling, some inflammatory cytokines may also exert protective actions on cardiomyocytes under conditions of stress. Chemokines, such as CCL2, are also upregulated in failing hearts and may stimulate recruitment of pro-inflammatory leukocytes, promoting myocardial injury, fibrotic remodeling, and dysfunction. Although experimental evidence suggests that cytokine and chemokine targeting may hold therapeutic promise in heart failure, clinical translation remains challenging. This review manuscript summarizes our knowledge on the role of TNF-α, IL-1, IL-6, and CCL2 in the pathogenesis of heart failure, and discusses the promises and challenges of targeted anti-cytokine therapy. Dissection of protective and maladaptive cellular actions of cytokines in the failing heart, and identification of patient subsets with overactive or dysregulated myocardial inflammatory responses are required for design of successful therapeutic approaches.

Exploiting common aspects of obesity and cancer cachexia for future therapeutic strategies

Obesity and cancer cachexia are diseases at opposite ends of the BMI. However, despite the apparent dichotomy, these pathologies share some common underlying mechanisms that lead to profound metabolic perturbations. Insulin resistance, adipose tissue lipolysis, skeletal muscle atrophy and systemic inflammation are key players in both diseases. Several strategies for pharmacological treatments have been employed in obesity and cancer cachexia but demonstrated only limited effects. Therefore, there is still a need to develop novel, more effective strategies. In this review we summarize existing therapies and discuss potential novel strategies that could arise by bridging common aspects between obesity and cachexia. We discuss the potential role of macrophage manipulation and the modulation of inflammation by targeting Nuclear Receptors (NRs) as potential novel therapeutic strategies.

Basic Mechanisms of Diabetic Heart Disease

Diabetes mellitus predisposes affected individuals to a significant spectrum of cardiovascular complications, one of the most debilitating in terms of prognosis is heart failure. Indeed, the increasing global prevalence of diabetes mellitus and an aging population has given rise to an epidemic of diabetes mellitus-induced heart failure. Despite the significant research attention this phenomenon, termed diabetic cardiomyopathy, has received over several decades, understanding of the full spectrum of potential contributing mechanisms, and their relative contribution to this heart failure phenotype in the specific context of diabetes mellitus, has not yet been fully resolved. Key recent preclinical discoveries that comprise the current state-of-the-art understanding of the basic mechanisms of the complex phenotype, that is, the diabetic heart, form the basis of this review. Abnormalities in each of cardiac metabolism, physiological and pathophysiological signaling, and the mitochondrial compartment, in addition to oxidative stress, inflammation, myocardial cell death pathways, and neurohumoral mechanisms, are addressed. Further, the interactions between each of these contributing mechanisms and how they align to the functional, morphological, and structural impairments that characterize the diabetic heart are considered in light of the clinical context: from the disease burden, its current management in the clinic, and where the knowledge gaps remain. The need for continued interrogation of these mechanisms (both known and those yet to be identified) is essential to not only decipher the how and why of diabetes mellitus-induced heart failure but also to facilitate improved inroads into the clinical management of this pervasive clinical challenge.

Distinct Types of Cell Death and the Implication in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM) is a chronic complication of diabetes mellitus, characterized by abnormalities of myocardial structure and function. Researches on the models of type 1 and type 2 diabetes mellitus as well as the application of genetic engineering technology help in understanding the molecular mechanism of DCM. DCM has multiple hallmarks, including hyperglycemia, insulin resistance, increased free radical production, lipid peroxidation, mitochondrial dysfunction, endothelial dysfunction, and cell death. Essentially, cell death is considered to be the terminal pathway of cardiomyocytes during DCM. Morphologically, cell death can be classified into four different forms: apoptosis, autophagy, necrosis, and entosis. Apoptosis, as type I cell death, is the fastest form of cell death and mainly occurs depending on the caspase proteolytic cascade. Autophagy, as type II cell death, is a degradation process to remove damaged proteins, dysfunctional organelles and commences by the formation of autophagosome. Necrosis is type III cell death, which contains a great diversity of cell death processes, such as necroptosis and pyroptosis. Entosis is type IV cell death, displaying “cell-in-cell” cytological features and requires the engulfing cells to execute. There are also some other types of cell death such as ferroptosis, parthanatos, netotic cell death, lysosomal dependent cell death, alkaliptosis or oxeiptosis, which are possibly involved in DCM. Drugs or compounds targeting the signals involved in cell death have been used in clinics or experiments to treat DCM. This review briefly summarizes the mechanisms and implications of cell death in DCM, which is beneficial to improve the understanding of cell death in DCM and may propose novel and ideal strategies in future.