JMJD3 is involved in neutrophil membrane proteinase 3 overexpression during the hyperinflammatory response in early sepsis

Cathepsin C from extracellular histone-induced M1 alveolar macrophages promotes NETosis during lung ischemia-reperfusion injury

Primary graft dysfunction (PGD) is a severe form of acute lung injury resulting from lung ischemia/reperfusion injury (I/R) in lung transplantation (LTx), associated with elevated post-transplant morbidity and mortality rates. Neutrophils infiltrating during reperfusion are identified as pivotal contributors to lung I/R injury by releasing excessive neutrophil extracellular traps (NETs) via NETosis. While alveolar macrophages (AMs) are involved in regulating neutrophil chemotaxis and infiltration, their role in NETosis during lung I/R remains inadequately elucidated. Extracellular histones constitute the main structure of NETs and can activate AMs. In this study, we confirmed the significant involvement of extracellular histone-induced M1 phenotype of AMs (M1-AMs) in driving NETosis during lung I/R. Using secretome analysis, public protein databases, and transwell co-culture models of AMs and neutrophils, we identified Cathepsin C (CTSC) derived from AMs as a major mediator in NETosis. Further elucidating the molecular mechanisms, we found that CTSC induced NETosis through a pathway dependent on NADPH oxidase-mediated production of reactive oxygen species (ROS). CTSC could significantly activate p38 MAPK, resulting in the phosphorylation of the NADPH oxidase subunit p47phox, thereby facilitating the trafficking of cytoplasmic subunits to the cell membrane and activating NADPH oxidase. Moreover, CTSC up-regulated and activated its substrate membrane proteinase 3 (mPR3), resulting in an increased release of NETosis-related inflammatory factors. Inhibiting CTSC revealed great potential in mitigating NETosis-related injury during lung I/R. These findings suggests that CTSC from AMs may be a crucial factor in mediating NETosis during lung I/R, and targeting CTSC inhition may represent a novel intervention for PGD in LTx.

α-Ketoglutarate-Dependent KDM6 Histone Demethylases and Interferon-Stimulated Gene Expression in Lupus

OBJECTIVE

We aimed to investigate the hypothesis that interferon (IFN)-stimulated gene (ISG) expression in systemic lupus erythematosus (SLE) monocytes is linked to changes in metabolic reprogramming and epigenetic regulation of ISG expression.

METHODS

Monocytes from healthy volunteers and patients with SLE at baseline or following IFNα treatment were analyzed by extracellular flux analysis, proteomics, metabolomics, chromatin immunoprecipitation, and gene expression. The histone demethylases KDM6A/B were inhibited using glycogen synthase kinase J4 (GSK-J4). GSK-J4 was tested in pristane and resiquimod (R848) models of IFN-driven SLE.

RESULTS

SLE monocytes had enhanced rates of glycolysis and oxidative phosphorylation compared to healthy control monocytes, as well as increased levels of isocitrate dehydrogenase and its product, α-ketoglutarate (α-KG). Because α-KG is a required cofactor for histone demethylases KDM6A and KDM6B, we hypothesized that IFNα may be driving "trained immune" responses through altering histone methylation. IFNα priming (day 1) resulted in a sustained increase in the expression of ISGs in primed cells (day 5) and enhanced expression on restimulation with IFNα. Importantly, decreased H3K27 trimethylation was observed at the promoters of ISGs following IFNα priming. Finally, GSK-J4 (KDM6A/B inhibitor) resulted in decreased ISG expression in SLE patient monocytes, as well as reduced autoantibody production, ISG expression, and kidney pathology in R848-treated BALB/c mice.

CONCLUSION

Our study suggests long-term IFNα exposure alters the epigenetic regulation of ISG expression in SLE monocytes via changes in immunometabolism, a mechanism reflecting trained immunity to type I IFN. Importantly, it opens the possibility that targeting histone-modifying enzymes, such as KDM6A/B, may reduce IFN responses in SLE.

Emodin inhibits bladder inflammation and fibrosis in mice with interstitial cystitis by regulating JMJD3

PURPOSE

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a devastating urological chronic pelvic pain condition. In search of a potential treatment, we investigated the effect of emodin on IC/BPS inflammation and fibrosis, and explore the potential mechanism.

METHODS

An experimental model of interstitial cystitis was induced by cyclophosphamide, and human bladder smooth muscle cells were treated with lipopolysaccharide to establish the cell model in vitro. In both models, inflammation- and fibrosis-related indexes were measured after emodin administration. Furthermore, the specific antagonists were used to dig for the mechanisms underlying the response to emodin treatment.

RESULTS

Emodin significantly ameliorated management of cystitis, reduced the amount of inflammatory cytokines (tumor necrosis factor-α, monocyte chemoattractant protein-1, interleukin-1β, interleukin-8, and interleukin-6) in models, as well as reducing the synthesis of fibrosis marker including collagen1, collagen3, vimentin, fibronectin and α-smooth muscle actin. Further mechanism studies demonstrated that emodin inhibited inflammatory reaction and fibrosis through blocking lysine-specific demethylase 6B (JMJD3) expression via JAK/STAT, NF-κB and TGF-β/SMAD pathways.

CONCLUSIONS

Our study reveals the critical role of emodin-JMJD3 signaling in interstitial cystitis by regulating inflammation, fibrosis, and extracellular matrix deposition in cells and tissues, and these findings provide an avenue for effective treatment of patients with cystitis.

25-Hydroxyvitamin D potentializes extracellular cathelicidin release from human PBMC stimulated ex vivo with either bacterial (LPS) or viral (P: IC) mimetics

Human cathelicidin refers to the cationic antimicrobial peptide hCAP18/LL-37. LL-37 is formed by cleavage of the propeptide hCAP18 coded by the CAMP gene. The active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)D), has been shown to induce the CAMP gene expression through promoter activation. We previously failed to demonstrate in a clinical trial that supplementation of 25-hydroxyvitamin D (25(OH)D) improves LL-37 serum levels. The aim of this work was to evaluate the impact of 25(OH)D supplementation on intracellular expression of CAMP and secretion of LL-37 in an ex vivo model using the peripheral blood mononuclear cells (PBMC). PBMC collected from healthy donors and incubated with different concentrations of 25(OH)D (0 ng/ml: control (D0); 25 ng/ml: deficient (D25); 75 ng/ml: physiological (D75); 125 ng/ml: supraphysiological (D125)) were stimulated or not with lipopolysaccharide (LPS, 100 ng/ml) or synthetic double-stranded RNA Poly (I: C) (PIC, 10 µg/ml). The intracellular expressions of the CAMP gene and the hCAP18 peptide were measured respectively after 24-h and 48-h incubation periods. The concentration of LL-37 was determined in the culture medium after 48-h incubation. 25(OH)D significantly induced CAMP gene expression at 24 h with a maximum effect at a dose of D125 in either unstimulated (tenfold expression) or stimulated (LPS: 100-fold expression; PIC: 15-fold expression) conditions. Intracellular hCAP18 peptide was overexpressed at 48 h under unstimulated (1.5-fold, D125) and stimulated conditions, LPS (twofold, D125) and PIC (2.5-fold, D125). The secretion of LL-37 in the culture medium was significantly induced by 25(OH)D only in both stimulated (LPS and PIC) conditions in a dose-dependent manner. Our results demonstrate that 25(OH)D incubation increases intracellular expression of CAMP and hCAP18, but extracellular secretion of LL-37 antimicrobial peptide is increased by 25(OH)D only when PBMC from healthy donors were stimulated with bacterial or viral immune mimetic.

YAP1 promotes high glucose-induced inflammation and extracellular matrix deposition in glomerular mesangial cells by modulating NF-κB/JMJD3 pathway

Diabetic nephropathy (DN) is one of the most serious microvascular complications of late-stage diabetes. Glomerular mesangial cell (GMC) proliferation and excessive extracellular matrix (ECM) deposition are the main pathological characteristics associated with the occurrence and development of DN. Yes-associated protein 1 (YAP1) can bind to several transcription factors and is associated with the development of various diseases. However, the effects of YAP1 on DN remain unclear. The aim of the present study was to explore the regulatory effect and potential mechanism of YAP1 in glucose-induced inflammation and ECM deposition in high-glucose-treated GMCs. In the present study, HBZY-1 cell models treated with high glucose were constructed, and the effects of YAP1 on the proliferation, inflammation, ECM deposition and fibrosis of HBZY-1 cells were detected. The results showed that YAP1 was highly expressed in HBZY-1 cells treated with high glucose and that YAP1 silencing decreased cell viability, the levels of inflammatory cytokines, ECM deposition and the degree of fibrosis in cells. Further experiments revealed that NF-κB/Jumonji domain-containing protein D3 (JMJD3) signaling pathway inhibitors alleviated the promoting effect of YAP1 overexpression on inflammatory response and ECM deposition in HBZY-1 cells treated with high glucose. In conclusion, it was demonstrated that YAP1 can promote high glucose-induced inflammation and ECM deposition by activating the NF-κB/JMJD3 signaling pathway in GMCs.

Comprehensive Analysis of Common Different Gene Expression Signatures in the Neutrophils of Sepsis

The central component of sepsis pathogenesis is inflammatory disorder, which is related to dysfunction of the immune system. However, the specific molecular mechanism of sepsis has not yet been fully elucidated. The aim of our study was to identify genes that are significantly changed during sepsis development, for the identification of potential pathogenic factors. Differentially expressed genes (DEGs) were identified in 88 control and 214 septic patient samples. Gene ontology (GO) and pathway enrichment analyses were performed using David. A protein-protein interaction (PPI) network was established using STRING and Cytoscape. Further validation was performed using real-time polymerase chain reaction (RT-PCR). We identified 37 common DEGs. GO and pathway enrichment indicated that enzymes and transcription factors accounted for a large proportion of DEGs; immune system and inflammation signaling demonstrated the most significant changes. Furthermore, eight hub genes were identified via PPI analysis. Interestingly, four of the top five upregulated and all downregulated DEGs were involved in immune and inflammation signaling. In addition, the most intensive hub gene AKT1 and the top DEGs in human clinical samples were validated using RT-PCR. This study explored the possible molecular mechanisms underpinning the inflammatory, immune, and PI3K/AKT pathways related to sepsis development.

Sepsis, immunosuppression and the role of epigenetic mechanisms

Introduction: Sepsis has pro- and anti-inflammatory processes caused by infectious agents. Sepsis survivors have impaired immune response due to immunosuppression. Gene expression during the inflammatory process is guided by transcriptional access to chromatin, with post-translational changes made in histones that determine whether the loci of the inflammatory gene are active, balanced, or suppressed. For this, a review literature was performed in PubMed included 'sepsis' and 'epigenetic' and 'immunosuppression' terms until May 2020.Areas covered: This review article explores the relationship between epigenetic mechanisms and the pathophysiology of sepsis. Epigenetic changes, vulnerable gene expression, and immunosuppression are related to inflammatory insults that can modify the dynamics of the central nervous system. Therefore, it is important to investigate the timing of these changes and their dynamics during the disease progression.Expert opinion: Epigenetic changes are associated with the main stages of sepsis, from the pathogen-host interaction to inflammation and immunosuppression. These changes are key regulators of gene expression during physiological and pathological conditions. Thus, epigenetic markers have significant prognostic and diagnostic potential in sepsis, and epigenetic changes can be explored in combination with therapeutic strategies in experimental models of the disease.

The demethylase inhibitor GSK-J4 limits inflammatory colitis by promoting de novo synthesis of retinoic acid in dendritic cells

Dendritic cells (DCs) promote T-cell mediated tolerance to self-antigens and induce inflammation to innocuous-antigens. This dual potential makes DCs fundamental players in inflammatory disorders. Evidence from inflammatory colitis mouse models and inflammatory bowel diseases (IBD) patients indicated that gut inflammation in IBD is driven mainly by T-helper-1 (Th1) and Th17 cells, suggesting an essential role for DCs in the development of IBD. Here we show that GSK-J4, a selective inhibitor of the histone demethylase JMJD3/UTX, attenuated inflammatory colitis by reducing the inflammatory potential and increasing the tolerogenic features of DCs. Mechanistic analyses revealed that GSK-J4 increased activating epigenetic signals while reducing repressive marks in the promoter of retinaldehyde dehydrogenase isoforms 1 and 3 in DCs, enhancing the production of retinoic acid. This, in turn, has an impact on regulatory T cells (Treg) increasing their lineage stability and gut tropism as well as potentiating their suppressive activity. Our results open new avenues for the treatment of IBD patients.

microRNA-27b shuttled by mesenchymal stem cell-derived exosomes prevents sepsis by targeting JMJD3 and downregulating NF-κB signaling pathway

Background

Exosomal microRNAs (miRs) derived from mesenchymal stem cells (MSCs) have been shown to play roles in the pathophysiological processes of sepsis. Moreover, miR-27b is highly enriched in MSC-derived exosomes. Herein, we aimed to investigate the potential role and downstream molecular mechanism of exosomal miR-27b in sepsis.

Methods

Inflammation was induced in bone marrow-derived macrophages (BMDMs) by lipopolysaccharide (LPS), and mice were made septic by cecal ligation and puncture (CLP). The expression pattern of miR-27b in MSC-derived exosomes was characterized using RT-qPCR, and its downstream gene was predicted by in silico analysis. The binding affinity between miR-27b, Jumonji D3 (JMJD3), or nuclear factor κB (NF-κB) was characterized to identify the underlying mechanism. We induced miR-27b overexpression or downregulation, along with silencing of JMJD3 or NF-κB to examine their effects on sepsis. The production of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 was detected by ELISA.

Results

miR-27b was highly expressed in MSC-derived exosomes. Mechanistic investigations showed that miR-27b targeted JMJD3. miR-27b decreased expression of pro-inflammatory genes by inhibiting the recruitment of JMJD3 and NF-κB at gene promoter region. Through this, MSC-derived exosomal miR-27b diminished production of pro-inflammatory cytokines in LPS-treated BMDMs and septic mice, which could be rescued by upregulation of JMJD3 and NF-κB. Besides, in vitro findings were reproduced by in vivo findings.

Conclusion

These data demonstrated that exosomal miR-27b derived from MSCs inhibited the development of sepsis by downregulating JMJD3 and inactivating the NF-κB signaling pathway.

Histone Demethylase JMJD3 Mediated Doxorubicin-Induced Cardiomyopathy by Suppressing SESN2 Expression

Jumonji domain-containing 3 (JMJD3) protein, a histone demethylase protein, specifically catalyzes the demethylation of H3K27 (H3K27me3) and regulates gene expression. Sestrin2 (SESN2), a stress-inducible protein, protected against doxorubicin (DOX)-induced cardiomyopathy by regulating mitophagy and mitochondrial function. Here, the expression of JMJD3 was increased and that of SESN2 was decreased in both the heart samples from patients with dilated cardiomyopathy and chronic DOX-stimulation induced cardiomyopathy. Inhibition or knockdown of JMJD3 attenuated DOX-induced cardiomyocytes apoptosis, mitochondrial injury and cardiac dysfunction. However, JMJD3 overexpression aggravated DOX-induced cardiomyopathy, which were relieved by SESN2 overexpression. JMJD3 inhibited the transcription of SESN2 by reducing tri-methylation of H3K27 in the promoter region of SESN2. In conclusion, JMJD3 negatively regulated SESN2 via decreasing H3K27me3 enrichment in the promoter region of SESN2, subsequently inducing mitochondrial dysfunction and cardiomyocytes apoptosis. Targeting the JMJD3-SESN2 signaling axis may be a potential therapeutic strategy to protect against DOX-mediated cardiomyopathy.

JMJD3 in the regulation of human diseases

In recent years, many studies have shown that histone methylation plays an important role in maintaining the active and silent state of gene expression in human diseases. The Jumonji domain-containing protein D3 (JMJD3), specifically demethylate di- and trimethyl-lysine 27 on histone H3 (H3K27me2/3), has been widely studied in immune diseases, infectious diseases, cancer, developmental diseases, and aging related diseases. We will focus on the recent advances of JMJD3 function in human diseases, and looks ahead to the future of JMJD3 gene research in this review.

The therapeutic effect of dexmedetomidine on protection from renal failure via inhibiting KDM5A in lipopolysaccharide-induced sepsis of mice

BACKGROUND

Sepsis is an inflammatory response undergoing the complicate pathophysiological changes for host defense against pathogens. Previous studies suggested that dexmedetomidine (DEX) was served to controlling the over-reactive inflammatory effects to protect from the sepsis-induced organ failure via modulating histone methylation. However, the genome-wide changes of histone methylations upon DEX for sepsis treatment were poorly explored.

MATERIALS AND METHODS

The acute kidney injury (AKI) mouse model were induced by lipopolysaccharide (LPS). DEX and KDM5 (H3K4 demethylases) inhibitors were used to add additionally. H3K4me3 antibody was used to conduct the ChIP-seq assay in renal cortex tissues.

RESULTS

We observed that the overall H3K4me3 levels were obviously declined in AKI group compared to the normal control. We further observed that the therapeutic effect of DEX was basically equal with CPI-455 and KDM5A-IN-1 but better than PBIT. The overall H3K4me3 level was reduced in AKI group compared to DEX (p = 0.008), and KDM5A-IN-1 groups (p = 0.022). The H3K4me3 enrichment of the multiple genes associated with inflammatory cytokines such as TNF-α, NOS2 and CCL2 increased in AKI model, but decreased upon DEX or KDM5A-IN-1 treatment. Consistently, transcription and protein levels of genes such as TLR4, MYD88, MTA1, PTGS2, CASP3 associated with NF-κB signaling pathway were all compromising after treated with DEX or KDM5A-IN-1 groups compared to AKI group.

CONCLUSION

Taken together, our data determined that DEX could attenuate AKI through KDM5A inhibition in sepsis.

Activation of NFKB-JMJD3 signaling promotes bladder fibrosis via boosting bladder smooth muscle cell proliferation and collagen accumulation

Chronic cystitis is characterized by the hyperplasia and fibrosis of the bladder wall as well as attenuated compliance of the bladder. To further unravel its underlying molecular mechanism, the role of NFκB-JMJD3 signaling pathway in cystitis induced bladder fibrosis was investigated. Jmjd3 and Col1/3 expression was detected in a cystitis mouse model that was developed by intraperitoneal injection of cyclophosphamide (CYP). Human bladder smooth muscle cells (hBSMCs) were stimulated in vitro with lipopolysaccharide (LPS), and the cell proliferation and collagen accumulation were detected using EdU, CCK8, flow cytometry, qPCR, western blotting and immunofluorescence assays. Furthermore, the effects of NFκB and JMJD3 on cell proliferation and collagen accumulation were investigated using its selective antagonists, JSH23 and GSK-J4, respectively. CYP induced cystitis significantly increased Jmjd3, Col1 and Col3 expression in the bladder muscle cells. Furthermore, LPS stimulation markedly activated NFκB signaling and elevated JMJD3 expression in hBSMCs, and the activation of NFκB-JMJD3 signaling significantly promoted cell proliferation and collagen accumulation by upregulating CCND1 and COL1/3 expression, respectively. Our study reveals the critical role of NFκB-JMJD3 signaling in cystitis induced bladder reconstruction by regulating hBSMC proliferation and extracellular matrix (ECM) deposition, and these findings provide an avenue for effective treatment of patients with cystitis.

GSKJ4 Protects Mice Against Early Sepsis via Reducing Proinflammatory Factors and Up-Regulating MiR-146a

Sepsis, defined as life-threatening organ dysfunction, is one of the most common causes of mortality in intensive care units with limited therapeutic options. However, the mechanism underlying the regulation of epigenetics on sepsis remains largely undefined. Here we showed that JMJD3, the histone lysine demethylase, played a critical role in the epigenetic regulation of innate immunity during early sepsis. Pharmacological inhibition of JMJD3 by GSKJ4 protected mice against early septic death and reduced pro-inflammatory cytokine interleukin-1β (IL-1β) production as well as IL-6, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) expression. Interestingly, GSKJ4 up-regulated the transcription of anti-inflammatory microRNA-146a (miR-146a) in peritoneal macrophages from septic mice. Mechanistically, JMJD3 negatively regulated the transcription of miR-146a via its demethylation of H3K27me3 on the promoter of miR-146a. Moreover, the transcription of miR-146a was positively regulated by nuclear factor-κB (NF-κB) p65. Inhibition of NF-κB p65 promoted JMJD3 binding to miR-146a promoter and decreased the tri-methylation level of H3K27, while the inhibition of JMJD3 did not affect the recruitment of NF-κB p65 to miR-146a promoter. These results highlight an epigenetic mechanism by which JMJD3 was inhibited by NF-κB p65 from binding to miR-146a promoter to promote the anti-inflammatory response. Taken together, our findings uncover a key role for JMJD3 in modulating the miR-146a transcription and shed light on the JMJD3 inhibitors could be potential therapeutic agents for early sepsis therapy.