Dpep2 Emerging as a Modulator of Macrophage Inflammation Confers Protection Against CVB3-Induced Viral Myocarditis

A High-Quality Blue Whale Genome, Segmental Duplications, and Historical Demography

The blue whale, Balaenoptera musculus, is the largest animal known to have ever existed, making it an important case study in longevity and resistance to cancer. To further this and other blue whale-related research, we report a reference-quality, long-read-based genome assembly of this fascinating species. We assembled the genome from PacBio long reads and utilized Illumina/10×, optical maps, and Hi-C data for scaffolding, polishing, and manual curation. We also provided long read RNA-seq data to facilitate the annotation of the assembly by NCBI and Ensembl. Additionally, we annotated both haplotypes using TOGA and measured the genome size by flow cytometry. We then compared the blue whale genome with other cetaceans and artiodactyls, including vaquita (Phocoena sinus), the world's smallest cetacean, to investigate blue whale's unique biological traits. We found a dramatic amplification of several genes in the blue whale genome resulting from a recent burst in segmental duplications, though the possible connection between this amplification and giant body size requires further study. We also discovered sites in the insulin-like growth factor-1 gene correlated with body size in cetaceans. Finally, using our assembly to examine the heterozygosity and historical demography of Pacific and Atlantic blue whale populations, we found that the genomes of both populations are highly heterozygous and that their genetic isolation dates to the last interglacial period. Taken together, these results indicate how a high-quality, annotated blue whale genome will serve as an important resource for biology, evolution, and conservation research.

M2 macrophage exosome-derived lncRNA AK083884 protects mice from CVB3-induced viral myocarditis through regulating PKM2/HIF-1α axis mediated metabolic reprogramming of macrophages

Viral myocarditis (VM) is a clinically common inflammatory disease. Accumulating literature has indicated that M2 macrophages protect mice from Coxsackievirus B3 (CVB3)-induced VM. However, mechanisms that underlie M2 macrophages alleviating myocardial inflammation remain largely undefined. We found that M2 macrophage-derived exosomes (M2-Exo) can effectively attenuate VM. The long non-coding RNA (lncRNA) AK083884 in M2-Exo was found to be involved in the regulation of macrophage polarization by exosome lncRNA sequencing combined with in vitro functional assays. M2-Exo-derived AK083884 promotes macrophage M2 polarization and protects mice from CVB3-induced VM. Furthermore, we identified pyruvate kinase M2 (PKM2) as a protein target binding to AK083884 and found that PKM2 knockdown could promote macrophages to polarize to M2 phenotype. Intriguingly, functional assay revealed that downregulation of AK083884 promotes metabolic reprogramming in macrophages. In addition, co-immunoprecipitation was performed to reveal AK083884 could interact with PKM2 and inhibition of AK083884 can facilitate the binding of PKM2 and HIF-1α. Collectively, our findings uncovered an important role of M2-Exo-derived AK083884 in the regulation of macrophage polarization through metabolic reprogramming, identified a new participant in the development of VM and provided a potential clinically important therapeutic target.

Ruxolitinib ameliorated coxsackievirus B3-induced acute viral myocarditis by suppressing the JAK-STAT pathway

BACKGROUND

Accumulating evidences have demonstrated that overwhelming inflammation occurs in the process of Coxsackievirus B3 (CVB3)-induced acute viral myocarditis (AVM). No specific therapy is available. More than an effective Janus-associated kinase (JAK) inhibiter, ruxolitinib exerts a critical role in the inflammatory diseases. In this study, we investigated the potential effect of ruxolitinib on CVB3-induced acute viral myocarditis.

METHOD

In vivo, BALB/c mice were intraperitoneally injected of CVB3, treated of a successive gavage of ruxolitinib for seven days, and subjected to a series of analysis. In vitro, primary bone marrow-derived macrophages (BMDMs) and cardiac fibroblasts were isolated, cultured, treated, harvested and finally detected.

RESULTS

In vivo, acute viral myocarditis was successfully induced by the injection of CVB3 characterized by impaired cardiac function, predominant infiltration of inflammatory cells, necroptosis of myocardium, great increase of cardiac troponin I (cTnI) and cytokine levels, replication of CVB3, and excessive activation of JAK-STAT pathways. Oral administration of ruxolitinib suppressed the activation of JAK-STAT pathway in a dosage-dependent way, lessened the infiltration of inflammatory cells and necroptosis of myocardium, reduced the levels of cTnI and cytokines, and finally alleviated CVB3-induced cardiac dysfunction, with the reduced production of type I interferon and no promising effect on the replication of CVB3. In vitro, the treatment of ruxolitinib inhibited the activation of JAK-STAT pathway and increase of multiple cytokines mRNA levels in BMDMs and had no protective effect against CVB3 replication in cardiac fibroblasts.

CONCLUSIONS

Our study suggested that ruxolitinib ameliorated CVB3-induced AVM by inhibiting the activation of JAK-STAT pathway, infiltration of inflammatory cells and necroptosis of myocardium, which may provide a novel strategy for AVM therapy.

Dipeptidase‑2 is a prognostic marker in lung adenocarcinoma that is correlated with its sensitivity to cisplatin

Lung cancer accounts for the highest percentage of cancer morbidity and mortality worldwide, and lung adenocarcinoma (LUAD) is the most prevalent subtype. Although numerous therapies have been developed for lung cancer, patient prognosis is limited by tumor metastasis and more effective treatment targets are urgently required. In the present study, gene expression profiles were extracted from the Gene Expression Omnibus database and mRNA expression data were downloaded from The Cancer Genome Atlas database. In addition, TIMER 2.0 database was used to analyze the expression of genes in normal and multiple tumor tissues. Protein expression was confirmed using the Human Protein Atlas database and LUAD cell lines, sphere formation assay, western blotting, and a xenograft mouse model were used to confirm the bioinformatics analysis. Dipeptidase‑2 (DPEP2) expression was significantly decreased in LUAD and was negatively associated with prognosis. DPEP2 overexpression substantially inhibited epithelial‑mesenchymal transition (EMT) as well as LUAD cell metastasis, and limited the expression of the cancer stem cell transformation markers, CD44 and CD133. In addition, DPEP2 improved LUAD sensitivity to cisplatin by inhibiting EMT; this was verified in vitro and in vivo. These data indicated that DPEP2 upregulates E‑cadherin, thereby regulating cell migration, cancer stem cell transformation, and cisplatin resistance, ultimately affecting the survival of patients with LUAD. Overall, the findings of the present suggest that DPEP2 is important in the development of LUAD and can be used both as a prognostic marker and a target for future therapeutic research.

Integrated Single-Cell and Transcriptome Sequencing Analyses Identify Dipeptidase 2 as an Immune-Associated Prognostic Biomarker for Lung Adenocarcinoma

Dipeptidase 2 (DPEP2) is a dipeptidyl peptidase that plays an important role in the hydrolysis of leukotriene D4 (LTD4) to leukotriene E4 (LTE4). Previous studies have suggested that LTD4 promotes tumor progression and survival in non-small cell lung cancer (NSCLC). Therefore, we hypothesized that DPEP2 may play a pivotal role in this tumor. Given that lung adenocarcinoma (LUAD) is the most common subtype of NSCLC, our study aimed to examine the expression and function of DPEP2 in LUAD. Based on bioinformatics and the analysis of clinical samples, our findings revealed that DPEP2 is highly expressed in normal lung tissues, but downregulated in LUAD tissues, and its expression levels were significantly associated with clinical indicators of tumor grade and prognosis. Pathway enrichment analysis showed that DPEP2 is involved in biological processes such as chemokine signaling pathways, leukocyte trans-endothelial migration, and humoral immune responses in LUAD. In addition, DPEP2 expression was significantly associated with various immune cells, especially monocytes-macrophages. Single-cell transcriptome data further confirmed the expression of DPEP2 dominantly in macrophages from normal lung tissues. Analysis of the TCIA database revealed that high DPEP2 expression is associated with a stronger response to immune checkpoint inhibitors such as CTLA4 and PD1, and determines sensitivity to LUAD therapeutic agents. Furthermore, we found that DPEP2 inhibits the migration and invasion of LUAD cells. Therefore, DPEP2 may serve as a potential immune biomarker and therapeutic target for LUAD, providing novel therapeutic approaches for this disease.

Sema3A alleviates viral myocarditis by modulating SIRT1 to regulate cardiomyocyte mitophagy

Viral myocarditis (VMC) is a common myocardial inflammatory disease characterized by inflammatory cell infiltration and cardiomyocyte necrosis. Sema3A was reported to reduce cardiac inflammation and improve cardiac function after myocardial infarction, but its role in VMC remains to be explored. Here, a VMC mouse model was established by infection with CVB3, and Sema3A was overexpressed in vivo by intraventricular injection of an adenovirus-mediated Sema3A expression vector (Ad-Sema3A). We found that Sema3A overexpression attenuated CVB3-induced cardiac dysfunction and tissue inflammation. And Sema3A also reduced macrophage accumulation and NLRP3 inflammasome activation in the myocardium of VMC mice. In vitro, LPS was used to stimulate primary splenic macrophages to mimic the macrophage activation state in vivo. Activated macrophages were co-cultured with primary mouse cardiomyocytes to evaluate macrophage infiltration-induced cardiomyocyte damage. Ectopic expression of Sema3A in cardiomyocytes effectively protected cardiomyocytes from activated macrophage-induced inflammation, apoptosis, and ROS accumulation. Mechanistically, cardiomyocyte-expressed Sema3A mitigated macrophage infiltration-caused cardiomyocyte dysfunction by promoting cardiomyocyte mitophagy and hindering NLRP3 inflammasome activation. Furthermore, NAM (a SIRT1 inhibitor) reversed the protective effect of Sema3A against activated macrophage-induced cardiomyocyte dysfunction by suppressing cardiomyocyte mitophagy. In conclusion, Sema3A promoted cardiomyocyte mitophagy and suppressed inflammasome activation by regulating SIRT1, thereby attenuating macrophage infiltration-induced cardiomyocyte injury in VMC.

Plasma protein changes reflect colorectal cancer development and associated inflammation

Introduction

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of death worldwide. Efficient non-invasive blood-based biomarkers for CRC early detection and prognosis are urgently needed.

Methods

To identify novel potential plasma biomarkers, we applied a proximity extension assay (PEA), an antibody-based proteomics strategy to quantify the abundance of plasma proteins in CRC development and cancer-associated inflammation from few μL of plasma sample.

Results

Among the 690 quantified proteins, levels of 202 plasma proteins were significantly changed in CRC patients compared to age-and-sex-matched healthy subjects. We identified novel protein changes involved in Th17 activity, oncogenic pathways, and cancer-related inflammation with potential implications in the CRC diagnosis. Moreover, the interferon γ (IFNG), interleukin (IL) 32, and IL17C were identified as associated with the early stages of CRC, whereas lysophosphatidic acid phosphatase type 6 (ACP6), Fms-related tyrosine kinase 4 (FLT4), and MANSC domain-containing protein 1 (MANSC1) were correlated with the late-stages of CRC.

Discussion

Further study to characterize the newly identified plasma protein changes from larger cohorts will facilitate the identification of potential novel diagnostic, prognostic biomarkers for CRC.

Role of Coxsackievirus B3-Induced Immune Responses in the Transition from Myocarditis to Dilated Cardiomyopathy and Heart Failure

Dilated cardiomyopathy (DCM) is a cardiac disease marked by the stretching and thinning of the heart muscle and impaired left ventricular contractile function. While most patients do not develop significant cardiac diseases from myocarditis, disparate immune responses can affect pathological outcomes, including DCM progression. These altered immune responses, which may be caused by genetic variance, can prolong cytotoxicity, induce direct cleavage of host protein, or encourage atypical wound healing responses that result in tissue scarring and impaired mechanical and electrical heart function. However, it is unclear which alterations within host immune profiles are crucial to dictating the outcomes of myocarditis. Coxsackievirus B3 (CVB3) is a well-studied virus that has been identified as a causal agent of myocarditis in various models, along with other viruses such as adenovirus, parvovirus B19, and SARS-CoV-2. This paper takes CVB3 as a pathogenic example to review the recent advances in understanding virus-induced immune responses and differential gene expression that regulates iron, lipid, and glucose metabolic remodeling, the severity of cardiac tissue damage, and the development of DCM and heart failure.

An immune indicator based on BTK and DPEP2 identifies hot and cold tumors and clinical treatment outcomes in lung adenocarcinoma

In lung adenocarcinoma (LUAD), immune heterogeneity of hot and cold tumors has been recognized as one of the major factors affecting immunotherapy and other common treatments. However, there is still a lack of biomarkers that can effectively identify the immunophenotype of cold and hot tumors. First, the immune signatures were obtained based on literature mining, including macrophage/monocyte, IFN-γ response, TGF-β response, IL12 response, lymphocyte activation, and ECM/Dve/immune response. Subsequently, LUAD patients were further clustered into different immune phenotypes based on these immune signatures. Next, the key genes related to the immune phenotypes were screened by WGCNA analysis, univariate analysis, and lasso-cox analysis, and the risk signature was established via the key genes. In additional, we compared the clinicopathological characteristics, drug sensitivity, the abundance of immune infiltration, and the efficacy of immunotherapy and commonly used therapies between patients in the high- and low-risk groups in LUAD. LUAD patients were divided into immune hot phenotype and immune cold phenotype groups. The clinical presentation showed that patients with the immune hot phenotype had higher immunoactivity (including higher MHC, CYT, immune, stromal, ESTIMATE scores, higher abundance of immune cell infiltration, higher abundance of TIL, and enrichment of immune-enriched subtypes) and better survival outcomes than those with the immune cold phenotype. Subsequently, WGCNA analysis, univariate analysis, and lasso-cox analysis identified the genes highly associated with the immune phenotype: BTK and DPEP2. The risk signature, consisting of BTK and DPEP2, is highly correlated with the immune phenotype. High-risk scores were enriched in patients with immune cold phenotype and low-risk scores were enriched in patients with immune hot phenotype. Compared to the high-risk group, the low-risk group had better clinical performance, higher drug sensitivity, and a higher degree of immunoactivity, as well as better efficacy in receiving immunotherapy and common adjuvant therapy. This study developed an immune indicator consisting of BTK and DPEP2 based on the heterogeneity of hot and cold Immunophenotypes of the tumor microenvironment. This indicator has good efficacy in predicting prognosis and assessing the efficacy of immunotherapy, chemotherapy, and radiotherapy. It has the potential to facilitate personalized and precise treatment of LUAD in the future.

Exploring the biological function of immune cell-related genes in human immunodeficiency virus (HIV)-1 infection based on weighted gene co-expression network analysis (WGCNA)

Background

Acquired immunodeficiency syndrome (AIDS) is a chronic infectious disease characterized by consistent immune dysfunction. The objective of this study is to determine whether immune cell-related genes can be used as biomarkers for the occurrence of AIDS and potential molecular mechanisms.

Methods

A weighted gene co-expression network analysis was performed using the GSE6740 dataset from the Gene Expression Synthesis Database to identify the Hub gene, which contained microarray data from HIV-1 positive (HIV-1⁺) and HIV-1 negative (HIV-1⁻) individuals. The HIV-1⁺-related differentially expressed genes were then identified using the limma package. Subsequently, the characteristic immune cell-related genes were identified as diagnostic biomarkers for HIV-1⁺ using the random forest model (RF), support vector machine model, and generalized linear model.

Results

MEdarkgreen exhibited the strongest correlation with HIV clinical features of any of these modules. As the best model for diagnosing HIV-1^±, RF was used to select four critical immune cell-related genes, namely, ARRB1, DPEP2, LTBP3, and RGCC, and a nomogram model was created to predict the occurrence of HIV-1 infection based on four key immune cell-related genes. Diagnostic genes were shown to be engaged in immune-related pathways, suggesting that immunological molecules, immune cells, and immune pathways all have a role in HIV-1 infection. The CTD database was explored for prospective medications or molecular compounds that might be utilized to treat HIV-1⁺ patients. = Moreover, in HIV-1⁺ individuals, the ceRNA network revealed that ARRB1, DPEP2, LTBP3, and RGCC could be regulated by lncRNAs through the corresponding miRNAs. Ultimately, RT-PCR results from clinical blood samples demonstrated that the four diagnostic genes were significantly downregulated in HIV-1⁺ patients.

Conclusion

We screened four immune cell-related genes, ARRB1, DPEP2, LTBP3, and RGCC, which may be considered as the diagnostic markers for HIV-1/AIDS. Our findings reveal that immune related genes and pathways involved in HIV-1 pathogenesis were regulated on both genetic and epigenetic levels by constructing a ceRNA network associated with lncRNA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01357-y.

The aryl hydrocarbon receptor instructs the immunomodulatory profile of a subset of Clec4a4+ eosinophils unique to the small intestine

C-type lectin domain family 4, member a4 (Clec4a4) is a C-type lectin inhibitory receptor specific for glycans thought to be exclusively expressed on murine CD8α− conventional dendritic cells. Using newly generated Clec4a4-mCherry knock-in mice, we identify a subset of Clec4a4-expressing eosinophils uniquely localized in the small intestine lamina propria. Clec4a4+ eosinophils evinced an immunomodulatory signature, whereas Clec4a4− eosinophils manifested a proinflammatory profile. Clec4a4+ eosinophils expressed high levels of aryl hydrocarbon receptor (Ahr), which drove the expression of Clec4a4 as well as other immunomodulatory features, such as PD-L1. The abundance of Clec4a4+ eosinophils was dependent on dietary AHR ligands, increased with aging, and declined in inflammatory conditions. Mice lacking AHR in eosinophils expanded innate lymphoid cells of type 2 and cleared Nippostrongylus brasiliensis infection more effectively than did wild-type mice. These results highlight the heterogeneity of eosinophils in response to tissue cues and identify a unique AHR-dependent subset of eosinophils in the small intestine with an immunomodulatory profile.

Identification of shared and disease-specific host gene-microbiome associations across human diseases using multi-omic integration

While gut microbiome and host gene regulation independently contribute to gastrointestinal disorders, it is unclear how the two may interact to influence host pathophysiology. Here we developed a machine learning-based framework to jointly analyse paired host transcriptomic (n = 208) and gut microbiome (n = 208) profiles from colonic mucosal samples of patients with colorectal cancer, inflammatory bowel disease and irritable bowel syndrome. We identified associations between gut microbes and host genes that depict shared as well as disease-specific patterns. We found that a common set of host genes and pathways implicated in gastrointestinal inflammation, gut barrier protection and energy metabolism are associated with disease-specific gut microbes. Additionally, we also found that mucosal gut microbes that have been implicated in all three diseases, such as Streptococcus, are associated with different host pathways in each disease, suggesting that similar microbes can affect host pathophysiology in a disease-specific manner through regulation of different host genes. Our framework can be applied to other diseases for the identification of host gene-microbiome associations that may influence disease outcomes.

DNA Methylation Mediates the Association Between Individual and Neighborhood Social Disadvantage and Cardiovascular Risk Factors

Low socioeconomic status (SES) and living in a disadvantaged neighborhood are associated with poor cardiovascular health. Multiple lines of evidence have linked DNA methylation to both cardiovascular risk factors and social disadvantage indicators. However, limited research has investigated the role of DNA methylation in mediating the associations of individual- and neighborhood-level disadvantage with multiple cardiovascular risk factors in large, multi-ethnic, population-based cohorts. We examined whether disadvantage at the individual level (childhood and adult SES) and neighborhood level (summary neighborhood SES as assessed by Census data and social environment as assessed by perceptions of aesthetic quality, safety, and social cohesion) were associated with 11 cardiovascular risk factors including measures of obesity, diabetes, lipids, and hypertension in 1,154 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). For significant associations, we conducted epigenome-wide mediation analysis to identify methylation sites mediating the relationship between individual/neighborhood disadvantage and cardiovascular risk factors using the JT-Comp method that assesses sparse mediation effects under a composite null hypothesis. In models adjusting for age, sex, race/ethnicity, smoking, medication use, and genetic principal components of ancestry, epigenetic mediation was detected for the associations of adult SES with body mass index (BMI), insulin, and high-density lipoprotein cholesterol (HDL-C), as well as for the association between neighborhood socioeconomic disadvantage and HDL-C at FDR q < 0.05. The 410 CpG mediators identified for the SES-BMI association were enriched for CpGs associated with gene expression (expression quantitative trait methylation loci, or eQTMs), and corresponding genes were enriched in antigen processing and presentation pathways. For cardiovascular risk factors other than BMI, most of the epigenetic mediators lost significance after controlling for BMI. However, 43 methylation sites showed evidence of mediating the neighborhood socioeconomic disadvantage and HDL-C association after BMI adjustment. The identified mediators were enriched for eQTMs, and corresponding genes were enriched in inflammatory and apoptotic pathways. Our findings support the hypothesis that DNA methylation acts as a mediator between individual- and neighborhood-level disadvantage and cardiovascular risk factors, and shed light on the potential underlying epigenetic pathways. Future studies are needed to fully elucidate the biological mechanisms that link social disadvantage to poor cardiovascular health.

Tumor purity as a prognosis and immunotherapy relevant feature in cervical cancer

Background: Tumor purity plays a vital role in the biological process of solid tumors, but its function in gynecologic cancers remains unclear. This study explored the correlation between tumor purity and immune function of gynecological cancers and its reliability as a prognostic indicator of immunotherapy.

Methods: Gynecological cancer-related datasets were downloaded from The Cancer Genome Atlas (TCGA). Tumor purity was calculated by the ESTIMATE algorithm. A LASSO Cox regression analysis was performed to construct the risk score model. A Kaplan–Meier Plotter was used to explore the relationships between tumor purity and cancer prognosis. We performed the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis (GSEA) to explore the pathways in the subgroups. A nomogram was used to quantitatively assess the cancer prognosis.

Results: Tumor purity was negatively correlated with B cell infiltration in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC). Approximately 420 genes were positively associated with B cell infiltration and CESC prognosis and were enriched in immune-related signaling pathways. There were 11 key genes used to construct a risk score model. The low-risk group had a higher immune score and better prognosis than the high-risk group. A nomogram based on risk score, T stage, and clinical-stage had good predictive value in quantitatively evaluating CESC prognosis.

Conclusions: This study is the first to reveal the correlation between tumor purity and immunity in CESC and suggests that low-risk patients may be more sensitive to immunotherapy. This provides a theoretical basis for the clinical treatment of CESC.

Lupeol alleviates coxsackievirus B3-induced viral myocarditis in mice via downregulating toll-like receptor 4

Objectives

To investigate the effect of lupeol in a mouse model of viral myocarditis induced by coxsackie virus B3 (CVB3).

Methods

Mice were separated into controls (DMEM, n = 20) and CVB3 infected groups (i.e., untreated CVB3 [n = 40]; CVB3 + lupeol 50 mg/kg [n = 40]; CVB3 + lupeol 100 mg/kg [n = 40]; CVB3 + small interfering RNA (siRNA)- toll-like receptor 4 (TLR4) [n = 20]; siRNA + EXP-H mice [n = 20]). Reverse transcription polymerase chain reaction (RT-PCR), western-blot assay, immunohistochemistry, enzyme-linked immunosorbent (ELISA) assay and histopathology were performed to investigate the cardioprotective role of lupeol.

Results

The elevated pro-inflammatory cytokines in CVB3-infected mice (i.e., interleukin-1β [IL-1β]; interleukin-6 [IL-6]; tumour necrosis factor-α [TNF-α]) were significantly reduced by lupeol 50 or 100 mg/kg. Interestingly, the mRNA level and protein level of toll-like receptor 4 (TLR4) were inhibited by lupeol.

Conclusions

Lupeol alleviates CVB3-induced viral myocarditis and myocardial damage in mice. The underlying mechanism may due to downregulation of TLR4.

The Role of Posttranslational Modification and Mitochondrial Quality Control in Cardiovascular Diseases

Cardiovascular disease (CVD) is the leading cause of death in the world. The mechanism behind CVDs has been studied for decades; however, the pathogenesis is still controversial. Mitochondrial homeostasis plays an essential role in maintaining the normal function of the cardiovascular system. The alterations of any protein function in mitochondria may induce abnormal mitochondrial quality control and unexpected mitochondrial dysfunction, leading to CVDs. Posttranslational modifications (PTMs) affect protein function by reversibly changing their conformation. This review summarizes how common and novel PTMs influence the development of CVDs by regulating mitochondrial quality control. It provides not only ideas for future research on the mechanism of some types of CVDs but also ideas for CVD treatments with therapeutic potential.

Cardiomyocyte-specific deletion of Senp2 contributes to CVB3 viral replication and inflammation

Viral myocarditis (VMC) is characterized by cardiac inflammation and excessive inflammatory responses after viral infection. SENP2, a deSUMO-specific protease, has been reported to regulate antiviral innate immunity. This study aimed to investigate whether SENP2 affects CVB3-induced VMC. We generated a CVB3-induced VMC mouse model in 6-week-old cardiomyocyte-specific Senp2 knockout mice. The mice were sacrificed at days 0, 2, 4 and 6 after CVB3 infection. The survival rate, body weight, myocardial histopathological changes, viral load, cytokine levels and antiviral gene expression in cardiac tissues of both groups were investigated. Our study indicated that the expression of Senp2 in primary cardiomyocytes was upregulated by CVB3 infection. Moreover, deletion of Senp2 in the heart exacerbated CVB3 infection-induced myocarditis, facilitated CVB3 viral replication and downregulated the expression of antiviral proteins. In conclusion, our findings suggest a protective role for SENP2 in CVB3-induced VMC.

The Role of Non-coding RNAs in Viral Myocarditis

Viral myocarditis (VMC) is a disease characterized as myocardial parenchyma or interstitium inflammation caused by virus infection, especially Coxsackievirus B3 (CVB3) infection, which has no accurate non-invasive examination for diagnosis and specific drugs for treatment. The mechanism of CVB3-induced VMC may be related to direct myocardial damage of virus infection and extensive damage of abnormal immune response after infection. Non-coding RNA (ncRNA) refers to RNA that is not translated into protein and plays a vital role in many biological processes. There is expanding evidence to reveal that ncRNAs regulate the occurrence and development of VMC, which may provide new treatment or diagnosis targets. In this review, we mainly demonstrate an overview of the potential role of ncRNAs in the pathogenesis, diagnosis and treatment of CVB3-induced VMC.

lncRNA AK085865 Promotes Macrophage M2 Polarization in CVB3-Induced VM by Regulating ILF2-ILF3 Complex-Mediated miRNA-192 Biogenesis

Accumulating evidence indicates that macrophage polarization plays a crucial role in coxsackievirus B3 (CVB3)-induced viral myocarditis (VM). Our previous study demonstrated that long noncoding ribonucleic acid (lncRNA) AK085865 ablation confers susceptibility to VM by regulating macrophage polarization. However, the detailed molecular mechanisms by which AK085865 regulates macrophage polarization remain to be explored. In this study, we found that AK085865 specifically interacts with interleukin enhancer-binding factor 2 (ILF2) and facilitates M2 macrophage polarization by functioning as a negative regulator in the ILF2-ILF3 complex-mediated microRNA (miRNA or miR) processing pathway. miR-192 was downregulated, whereas the levels of pri-miR-192 were significantly increased in bone marrow-derived macrophages (BMDMs) from AK085865^-/- mice compared with the BMDMs from wild-type (WT) mice. Conversely, knockdown of ILF2 resulted in elevated levels of mature miR-192 and decreased expression of pri-miR-192 in BMDMs from AK085865^-/- mice. Moreover, miR-192 overexpression promoted macrophage M2 polarization in vitro, and interleukin-1 receptor-associated kinase 1 (IRAK1) was identified as a direct target. miR-192 overexpression effectively rescued mice from lethal myocarditis caused by CVB3 infection and switched myocardial-infiltrating macrophages to a predominant M2 phenotype. Collectively, our findings uncover a critical mechanism of AK085865 in the regulation of macrophage polarization in vitro and in vivo and provide a potential, clinically significant therapeutic target.