Decitabine and 5-azacitidine both alleviate LPS induced ARDS through anti-inflammatory/antioxidant activity and protection of glycocalyx and inhibition of MAPK pathways in mice

A focus on c-Jun-N-terminal kinase signaling in sepsis-associated multiple organ dysfunction: Mechanisms and therapeutic strategies

Sepsis is a life-threatening condition characterized by a widespread inflammatory response to infection, inevitably leading to multiple organ dysfunctions. Extensive research, both in vivo and in vitro, has revealed key factors contributing to sepsis, such as apoptosis, inflammation, cytokine release, oxidative stress, and systemic stress. The changes observed during sepsis-induced conditions are mainly attributed to altered signal transduction pathways, which play a critical role in cell proliferation, migration, and apoptosis. C-Jun N-terminal kinases, JNKs, and serine/threonine protein kinases in the mitogen-activated super family have gained considerable interest for their contribution to cellular events under sepsis conditions. JNK1 and JNK2 are present in various tissues like the lungs, liver, and intestine, while JNK3 is found in neurons. The JNK pathway plays a crucial role in the signal transduction of cytokines related to sepsis development, notably TNF-α and IL-1β. Activated JNK leads to apoptosis, causing tissue damage and organ dysfunction. Further, JNK activation is significant in several inflammatory conditions. Pharmacologically inhibiting JNK has been shown to prevent sepsis-associated damage across multiple organs, including the lungs, liver, intestines, heart, and kidneys. Multiple signaling pathways have been implicated in sepsis, including JNK/c-Myc, Mst1-JNK, MKK4-JNK, JNK-dependent autophagy, and Sirt1/FoxO3a. The review examines the role of JNK signaling in the development of sepsis-induced multiple-organ dysfunction through specific mechanisms. It also discusses different therapeutic approaches to target JNK. This review emphasizes the potential of JNKs as targets for the development of therapeutic agents for sepsis and the associated specific organ damage.

Factors affecting neutrophil functions during sepsis: human microbiome and epigenetics

Sepsis is a severe disease that occurs when the body's immune system reacts excessively to infection. The body's response, which includes an intense antibacterial reaction, can damage its tissues and organs. Neutrophils are the major components of white blood cells in circulation, play a vital role in innate immunity while fighting against infections, and are considered a feature determining sepsis classification. There is a plethora of basic research detailing neutrophil functioning, among which, the study of neutrophil extracellular traps is providing novel insights into mechanisms and treatments of sepsis. This review explores their functions, dysfunctions, and influences in the context of sepsis. The interplay between neutrophils and the human microbiome and the impact of DNA methylation on neutrophil function in sepsis are crucial areas of study. The interaction between neutrophils and the human microbiome is complex, particularly in the context of sepsis, where dysbiosis may occur. We highlight the importance of deciphering neutrophils' functional alterations and their epigenetic features in sepsis because it is critical for defining sepsis endotypes and opening up the possibility for novel diagnostic methods and therapy. Specifically, epigenetic signatures are pivotal since they will provide a novel implication for a sepsis diagnostic method when used in combination with the cell-free DNA. Research is exploring how specific patterns of DNA methylation in neutrophils, detectable in cell-free DNA, could serve as biomarkers for the early detection of sepsis.

Suppressing Endoplasmic Reticulum Stress Alleviates LPS-Induced Acute Lung Injury via Inhibiting Inflammation and Ferroptosis

Acute lung injury (ALI) is a life-threatening clinical disorder with high mortality rate. Ferroptosis is a new type of programmed cell death with lipid peroxidation and iron ion overloading as the main characteristics. Endoplasmic reticulum (ER) stress and ferroptosis play pivotal roles in the pathogenesis of ALI. The study aimed to investigate the underlying relationship between ER stress and ferroptosis in ALI. The ER stress inhibitor 4-phenylbutyric acid (4-PBA) alleviated LPS-induced inflammation, and decreased IL-1β, IL-6, and TNF-α levels in BALF and lungs. The increased MDA and decreased GSH induced by LPS were partially reversed by 4-PBA, which also inhibited the expressions of ferroptosis-related protein ACSL4, COX-2, and FTH1. TEM further confirmed the ferroptosis within airway epithelia cells was ameliorated by 4-PBA. Moreover, 4-PBA reduced the production of ROS and lipid ROS in LPS-exposed BEAS-2B cells in a concentration-dependent way. Meanwhile, 4-PBA mitigated LPS-induced cell apoptosis in vivo and in vitro. Mechanistically, the MAPK signaling pathway activated by LPS was downregulated by 4-PBA. Collectively, these findings suggested that 4-PBA protected against ALI by inhibiting inflammation and ferroptosis through downregulating ER stress, thus providing a potential intervention for ALI and revealing the possible interaction between ER stress and ferroptosis in ALI.

Identification and Analysis of PANoptosis-Related Genes in Sepsis-Induced Lung Injury by Bioinformatics and Experimental Verification

Purpose

Sepsis-induced lung injury (SLI) is a serious complication of sepsis. PANoptosis, a novel form of inflammatory programmed cell death that is not yet to be fully investigated in SLI. Our research aims to screen and validate the signature genes of PANoptosis in SLI by bioinformatics and in vivo experiment.

Methods

SLI-related datasets were downloaded from NCBI Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) of SLI were identified and intersected with the PANoptosis gene set to obtain DEGs related to PANoptosis (SPAN_DEGs). Then, Protein-Protein Interaction (PPI) network and functional enrichment analysis were conducted based on SPAN_DEGs. SVM-REF, LASSO and RandomForest three algorithms were combined to identify the signature genes. The Nomogram and ROC curves were performed to predict diagnostic value. Immune infiltration analysis, correlation analysis and differential expression analysis were used to explore the immunological characterization, correlation and expression levels of the signature genes. Finally, H&E staining and qRT-PCR were conducted for further verification in vivo experiment.

Results

Twenty-four SPAN_DEGs were identified by intersecting 675 DEGs with the 277 PANoptosis genes. Four signature genes (CD14, GSDMD, IL1β, and FAS) were identified by three machine learning algorithms, which were highly expressed in the SLI group, and had high diagnostic value in the diagnostic model. Moreover, immune infiltration analysis showed that most immune cells and immune-related functions were higher in the SLI group than those in the control group and were closely associated with the signature genes. Finally, it was confirmed that the cecum ligation and puncture (CLP) group mice showed significant pathological damage in lung tissues, and the mRNA expression levels of CD14, IL1β, and FAS were significantly higher than the sham group.

Conclusion

CD14, FAS, and IL1β may be the signature genes in PANoptosis to drive the progression of SLI and involved in regulating immune processes.

Sema3A inactivates the ERK/JNK signalling pathways to alleviate inflammation and oxidative stress in lipopolysaccharide-stimulated rat endothelial cells and lung tissues

Semaphorin 3A (Sema3A) is a secretory member of the semaphorin family of immune response regulators. This research focuses on its effects on inflammation and oxidative stress in acute respiratory distress syndrome (ARDS). By analysing the GEO dataset GSE57011, we obtained Sema3A as the most downregulated gene in ARDS samples. Lipopolysaccharide (LPS) was used to stimulate rat pulmonary microvascular endothelial cells (PMVECs) and rats to induce ARDS-like symptoms in vitro and in vivo, respectively. LPS induced severe damage in rat lung tissues, in which reduced immunohistochemical staining of Sema3A was detected. Sema3A overexpression reduced apoptosis and angiogenesis of LPS-induced PMVECs and alleviated lung injury and pulmonary edoema of rats. Moreover, ELISA results showed that Sema3A overexpression downregulated the levels of inflammatory cytokines and oxidative stress markers both in PMVECs and the rat lung. Activation of ERK/JNK signalling aggravated LPS-induced damage on PMVECs; however, the aggravation was partly blocked by Sema3A, which suppressed phosphorylation of ERK/JNK. Overall, this study demonstrates that Sema3A inactivates the ERK/JNK signalling to ameliorate inflammation and oxidative stress in LPS-induced ARDS models. Sema3A might therefore represent a candidate option for ARDS treatment.

A missing jigsaw within the hygiene hypothesis: Low-dose bisphenol A exposure attenuates lipopolysaccharide-induced asthma protection

The rising occurrence of allergic asthma in early life across industrialized countries suggests that environmental factors play a crucial role in determining asthma susceptibility and severity. While prior exposure to microbial lipopolysaccharides (LPSs) has been found to offer protection against allergic asthma, infants residing in urban environments are increasingly exposed to environmental pollutants. Utilizing limulus lysate test screens and virtual screening models, we identified pollutants that can modulate LPS bioactivity. This investigation revealed that bisphenol A (BPA), a chemical commonly used in numerous household items and previously implicated in obesity and cancer, effectively neutralizes LPS. In-depth mechanistic analyses showed that BPA specifically binds to the lipid A component of LPS, leading to inactivation. This interaction eliminates the immunostimulatory activity of LPS, making mice more susceptible to house dust mite (HDM)-induced allergic asthma. BPA reactivates lung epithelial cells, consequently amplifying type 2 responses to HDMs in dendritic cells. This chemical interplay provides new insights into the pathophysiology of asthma in relation to human exposure. Understanding the intricate relationships between environmental chemicals and microbial antigens, as well as their impacts on innate immunity, is critical for the development of intervention strategies to address immune disorders resulting from urbanization.

Effects of DNA methylase inhibitors in a murine model of severe BPD

DNA methylation is necessary for developmental gene regulation, but adverse environments result in aberrant methylation and gene silencing. The current pilot study tested the hypothesis that treatment with DNA methylation inhibitors (decitabine; RG108) would improve alveolarization in a newborn murine model of severe bronchopulmonary dysplasia. Newborn mice exposed to maternal inflammation (LPS) and neonatal hyperoxia (85% O2) were treated with decitabine (p3, 0.1 mg/kg; p2, 4, 6, 0.1 mg/kg; or p2, 4, 6, 0.15 mg/kg) or RG108 (p3, 0.0013 mg/kg) delivered intranasally. Modest improvements in alveolarization were observed with decitabine, but no differences were observed with RG108. Attenuated phospho-SMAD2/3 levels and greater surfactant protein C protein levels compared to vehicle were observed with some tested doses. No detrimental side effects were observed with the doses used in this study. In summary, our pilot investigations identified a safe dose for intranasal administration of both methylation inhibitors and provides a foundation for further studies into methylation inhibitors in the context of neonatal lung injury.

Personalizing Care for Critically Ill Adults Using Omics: A Concise Review of Potential Clinical Applications

Current guidelines for critically ill patients use broad recommendations to promote uniform protocols for the management of conditions such as acute kidney injury, acute respiratory distress syndrome, and sepsis. Although these guidelines have enabled the substantial improvement of care, mortality for critical illness remains high. Further outcome improvement may require personalizing care for critically ill patients, which involves tailoring management strategies for different patients. However, the current understanding of disease heterogeneity is limited. For critically ill patients, genomics, transcriptomics, proteomics, and metabolomics have illuminated such heterogeneity and unveiled novel biomarkers, giving clinicians new means of diagnosis, prognosis, and monitoring. With further engineering and economic development, omics would then be more accessible and affordable for frontline clinicians. As the knowledge of pathophysiological pathways mature, targeted treatments can then be developed, validated, replicated, and translated into clinical practice.

Mapping of DNA methylation-sensitive cellular processes in gingival and periodontal ligament fibroblasts in the context of periodontal tissue homeostasis

Interactions between gingival fibroblasts (GFs) and oral pathogens contribute to the chronicity of inflammation in periodontitis. Epigenetic changes in DNA methylation are involved in periodontitis pathogenesis, and recent studies indicate that DNA methyltransferase (DNMT) inhibitors may protect against epithelial barrier disruption and bone resorption. To assess the impact of DNMT inhibition on GFs, cells were cultured with decitabine (5-aza-2'-deoxycytidine, DAC) for 12 days to induce DNA hypomethylation. We observed several potentially detrimental effects of DAC on GF biological functions. First, extended treatment with DAC reduced GF proliferation and induced necrotic cell death. Second, DAC amplified Porphyromonas gingivalis- and cytokine-induced expression and secretion of the chemokine CCL20 and several matrix metalloproteinases (MMPs), including MMP1, MMP9, and MMP13. Similar pro-inflammatory effects of DAC were observed in periodontal ligament fibroblasts. Third, DAC upregulated intercellular adhesion molecule-1 (ICAM-1), which was associated with increased P. gingivalis adherence to GFs and may contribute to bacterial dissemination. Finally, analysis of DAC-induced genes identified by RNA sequencing revealed increased expression of CCL20, CCL5, CCL8, CCL13, TNF, IL1A, IL18, IL33, and CSF3, and showed that the most affected processes were related to immune and inflammatory responses. In contrast, the genes downregulated by DAC were associated with extracellular matrix and collagen fibril organization. Our observations demonstrate that studies of DNMT inhibitors provide important insights into the role of DNA methylation in cells involved in periodontitis pathogenesis. However, the therapeutic potential of hypomethylating agents in periodontal disease may be limited due to their cytotoxic effects on fibroblast populations and stimulation of pro-inflammatory pathways.

Disturbed Flow-Facilitated Margination and Targeting of Nanodisks Protect against Atherosclerosis

Disturbed blood flow induces endothelial pro-inflammatory responses that promote atherogenesis. Nanoparticle-based therapeutics aimed at treating endothelial inflammation in vasculature where disturbed flow occurs may provide a promising avenue to prevent atherosclerosis. By using a vertical-step flow apparatus and a microfluidic chip of vascular stenosis, herein, it is found that the disk-shaped versus the spherical nanoparticles exhibit preferential margination (localization and adhesion) to the regions with the pro-atherogenic disturbed flow. By employing a mouse model of carotid partial ligation, superior targeting and higher accumulation of the disk-shaped particles are also demonstrated within disturbed flow areas than that of the spherical particles. In hyperlipidemia mice, administration of disk-shaped particles loaded with hypomethylating agent decitabine (DAC) displays greater anti-inflammatory and anti-atherosclerotic effects compared with that of the spherical counterparts and exhibits reduced toxicity than "naked" DAC. The findings suggest that shaping nanoparticles to disk is an effective strategy for promoting their delivery to atheroprone endothelia.

Deciphering the role of damage-associated molecular patterns and inflammatory responses in acute lung injury

Acute lung injury (ALI) is characterized by diffuse pulmonary infiltrates and causes great mortality. ALI presents with overproduction of proinflammatory cytokines, cell death, destruction of alveoli-endothelial barriers, and neutrophil infiltration in lung tissues. Damage-associated molecular patterns (DAMPs) are molecules released from damaged cells due to infection, trauma, etc. DAMPs activate innate and adaptive immunity, trigger inflammatory responses, and are important in the initiation and development of ALI. We reviewed the literatures on DAMPs in ALI. Alveolar macrophages (AMs), neutrophils, and epithelial cells (AECs) are important in the pathogenesis of ALI. We comprehensively analyzed the interaction between DAMPs and AMs, alveolar neutrophils, and AECs. During the initial stage of ALI, ruptured cell membranes or destroyed mitochondria release DAMPs. DAMPs activate the inflammasome in nearby sentinel immune cells, such as AMs. AMs produce IL-1β and other cytokines. These mediators upregulate adhesion molecules of the capillary endothelium that facilitate neutrophil recruitment. The recruited neutrophils detect DAMPs using formyl peptide receptors on the membrane, guiding their migration to the injured site. The accumulation of immune cells, cytokines, chemokines, proteases, etc., results in diffuse alveolar damage and pulmonary hyperpermeability with protein-rich fluid retention. Some clinical studies have shown that patients with ALI with higher circulating DAMPs have higher mortality rates. In conclusion, DAMPs are important in the initiation and progression of ALI. The interactions between DAMPs and AMs, neutrophils, and AECs are important in ALI. This review comprehensively addresses the mechanisms of DAMPs and their interactions in ALI.

Anti-inflammatory effects of a SERP 30 polysaccharide from the residue of Sarcandra glabra against lipopolysaccharide-induced acute respiratory distress syndrome in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Sarcandra glabra (Thunb.) Nakai, a valuable dietetic Chinese herb, is still widely used today. Multiple ingredients of S. glabra with a variety of activities such as anti-inflammatory, antiviral, and antitumor were studied. However, the Sarcandra glabra (Thunb.) Nakai polysaccharide hasn't been reported for its anti-inflammatory effect.

AIM OF THE STUDY

In this study, the anti-inflammatory activity of Sarcandra glabra (Thunb.) Nakai polysaccharide was assessed in LPS-induced ARDS mice.

MATERIALS AND METHODS

A polysaccharide coded as SERP 30 was obtained by water extraction, alcohol precipitation, and gel filtration. After the physicochemical properties determination and structural characterization, LPS induced-mice ARDS model was used to evaluate the anti-inflammatory and associated antioxidant activities of SERP 30. H&E staining was used to observe the seriousness of lung injury in mice. The ELISA method was used to measure the expression of inflammatory factors (TNF-α and IL-6) in the serum of the mice. The TBA method and the WST-1 method were used to evaluate the oxidative stress injury. Immunohistochemistry was used to distinguish the expression of metalloproteinase-9 (MMP-9), heparinase (HPA), syndecan-1, and decorin in ARDS-mice lung tissue. Western blotting was used to confirm the expression of related proteins in mouse lung tissue.

RESULTS

SERP 30 had a potential role in improving lung damage, reducing inflammation, and preventing oxidative stress. Moreover, SERP 30 significantly attenuated the damage to the endothelial glycocalyx and maintained the integrity of the glycocalyx. The western blotting result implied that the main anti-inflammatory mechanism is directed towards NF-κB and MAPK signaling pathways with inhibiting the activation of associated proteins.

CONCLUSION

This research provides a theoretical basis for treating ARDS by using a byproduct from food resource.

Epigenetics-mediated pathological alternations and their potential in antiphospholipid syndrome diagnosis and therapy

APS (antiphospholipid syndrome) is a systematic autoimmune disease accompanied with venous or arterial thrombosis and poor pregnant manifestations, partly attributing to the successive elevated aPL (antiphospholipid antibodies) and provoked prothrombotic and proinflammatory molecules production. Nowadays, most researches focus on the laboratory detection and clinic features of APS, but its precise etiology remains to be deeply explored. As we all know, the dysfunction of ECs (endothelial cells), monocytes, platelets, trophoblasts and neutrophils are key contributors to APS progression. Especially, their epigenetic variations, mainly including the promoter CpGs methylation, histone PTMs (post-translational modifications) and ncRNAs (noncoding RNAs), result in genes expression or silence engaged in inflammation initiation, thrombosis formation, autoimmune activation and APOs (adverse pregnancy outcomes) in APS. Given the potential of epigenetic markers serving as diagnostic biomarkers or therapeutic targets of APS, and the encouraging advancements in epigenetic drugs are being made. In this review, we would systematically introduce the epigenetic underlying mechanisms for APS progression, comprehensively elucidate the functional mechanisms of epigenetics in boosting ECs, monocytes, platelets, trophoblasts and neutrophils. Lastly, the application of epigenetic alterations for probing novel diagnostic, specific therapeutic and prognostic strategies would be proposed.

Protective effects of lotus plumule ethanol extracts on bleomycin-induced pulmonary fibrosis in mice

Pulmonary fibrosis (PF) is a progressive fibrosing disease, characterized by excessive accumulation of extracellular matrix (ECM) and remodeling of the lung architecture, which finally result in respiratory failure. Currently, there is no satisfactory treatment for PF， therefore, the development of effective agents is urgently needed. Lotus plumule, the green embryo of Nelumbo nucifera Gaertn., a plant of the Nymphaeaceae family, is a traditional Chinese food with exceptional nutritional value and its extracts exert prominent anti-inflammatory and anti-fibrotic effects. The aim of the present study was to investigate the inhibitory effects of lotus plumule extracts (LPEs) on bleomycin (BLM)-induced PF in mice. Therefore, enzyme-linked immunosorbent assay, RT-PCR, and western blot analysis were performed. The histopathological examination demonstrated that LPEs could obviously decrease the degree of alveolitis, deposition of ECM and the production of collagen I (Col-I) in the pulmonary interstitium. In addition, the results showed that LPEs markedly alleviated the expression of interleukin (IL)-6, IL-17, transforming growth factor (TGF)-β, and α-smooth muscle actin (α-SMA). Additionally, the content of Col-I and hydroxyproline (HYP) was also attenuated. In conclusion, LPEs could ameliorate the BLM-induced lung fibrosis, thus suggesting that LPEs could serve as a potential therapeutic approach for PF.

Epigenetics of Sepsis

OBJECTIVES

Recent evidence from the fields of microbiology and immunology, as well as a small number of human sepsis studies, suggest that epigenetic regulation may play a central role in the pathogenesis of sepsis. The term "epigenetics" refers to regulatory mechanisms that control gene expression but are not related to changes in DNA sequence. These include DNA methylation, histone modifications, and regulation of transcription via non-coding RNAs. Epigenetic modifications, occurring in response to external stressors, lead to changes in gene expression, and thus lie at the intersection between genetics and the environment. In this review, we examine data from in vitro studies, animal studies, and the existing human sepsis studies in epigenetics to demonstrate that epigenetic mechanisms are likely central to the pathogenesis of sepsis and that epigenetic therapies may have potential in the treatment of sepsis and its associated organ failures.

DATA SOURCES

Online search of published scientific literature via Pubmed using the term "epigenetics" in combination with the terms "sepsis", "infection", "bacterial infection", "viral infection", "critical illness", "acute respiratory distress syndrome", and "acute lung injury".

STUDY SELECTION

Articles were chosen for inclusion based on their relevance to sepsis, acute inflammation, sepsis-related immune suppression, and sepsis-related organ failure. Reference lists were reviewed to identify additional relevant articles.

DATA EXTRACTION

Relevant data was extracted and synthesized for narrative review.

DATA SYNTHESIS

Epigenetic regulation is a key determinant of gene expression in sepsis. At the onset of infection, host-pathogen interactions often result in epigenetic alterations to host cells that favor pathogen survival. In parallel, the host inflammatory response is characterized by epigenetic modifications in key regulatory genes, including tumor necrosis factor and interleukin-1β. In human sepsis patients, multiple epigenetic modifying enzymes show differential expression in early sepsis, suggesting a role for epigenetics in coordinating the response to infection. In the later stages of sepsis, epigenetic modifications accompany endotoxin tolerance and the immune-suppressed state. In animal models, treatment with epigenetic modifiers can mitigate the effects of sepsis and improve survival as well as reverse sepsis-associated organ injury.

CONCLUSIONS

Epigenetic modifications are associated with key phases of sepsis, from the host-pathogen interaction, to acute inflammation, to immune suppression. Epigenetic markers show promise in the diagnosis and prognosis of sepsis and epigenetic modifying agents show promise as therapeutic tools in animal models of sepsis. Human studies in the area of epigenetics are sorely lacking and should be a priority for sepsis researchers.

5-aza-2'-deoxycytidine may regulate the inflammatory response of human odontoblast-like cells through the NF-κB pathway

AIM

To explore the role of DNA methylation in the innate immunity of the dental pulp, this study investigated the effect of 5-aza-2'-deoxycytidine (AZA) on lipoteichoic acid (LTA)-induced cytokine production and related intracellular signalling pathways in human odontoblast-like cells (hOBs).

METHODOLOGY

hOBs were cultured and differentiated from human dental pulp tissue, and the odontoblastic phenotype of the cells was detected using immunofluorescence, qRT-PCR and Western blotting. hOBs were pretreated with AZA and then stimulated with 10 μg mL^-1 LTA. The levels of 42 cytokines related to immunity and inflammation were examined using a cytokine antibody array and verified using qRT-PCR and ELISA. The effect of AZA on the LTA-induced NF-κB and MAPK signalling pathways was explored using Western blotting. The cells were treated with the specific NF-κB inhibitor PDTC and MAPK inhibitors (the ERK inhibitor U0126, the p38 inhibitor SB203580, and the JNK inhibitor SP600125) to further confirm the role of the signalling pathways in LTA-treated hOBs. DNA immunoprecipitation-PCR was used to examine the dynamic methylation status of the gene promoters of myeloid differentiation primary response 88 (MyD88) and tumour necrosis factor receptor-associated factor 6 (TRAF6) in the LTA-induced hOBs. Statistical analyses of the differences between two groups were performed using Student's t-test. One-way analysis of variance (anova) or repeated-measures anova with a post hoc Dunnett's test was used to assess the differences between multiple sets of data. P < 0.05 was considered to be statistically significant.

RESULTS

The odontoblastic markers were significantly higher in hOBs than those in human dental pulp cells (hDPCs) (P < 0.05). According to the cytokine antibody array results, hOBs pretreated with AZA had significantly increased production of several inflammatory cytokines (P < 0.05), in which the expression levels of IL-6 and IL-8 were the most dramatically increased upon LTA stimulation (P < 0.01). Furthermore, AZA resulted in the significant upregulation of p-IKKα/β, p-IκBα, p-p65, p-p38 and p-ERK in LTA-stimulated hOBs (P < 0.01). Treatment with the NF-κB pathway inhibitor suppressed both IL-6 and IL-8 expression (P < 0.05), whereas inhibitors of the MAPK pathway (SB203580 and SP600125) did not. In LTA-treated hOBs, AZA significantly increased the expression levels of TRAF6 and MyD88 (P < 0.05). AZA induced MyD88 promoter hypomethylation but did not affect TRAF6 methylation.

CONCLUSION

AZA regulated the LTA-induced inflammatory response through the NF-κB signal pathway in hOBs. This study highlights the important role of DNA methylation in the immunity defence of odontoblasts during the dental pulp immunity response to caries.

Identification of Genes with Altered Methylation and Its Role in Early Diagnosis of Sepsis-Induced Acute Respiratory Distress Syndrome

Purpose

Early diagnosis of sepsis-induced acute respiratory distress syndrome (ARDS) is critical for effective treatment. We aimed to identify early stage biomarkers.

Materials and Methods

Differentially expressed genes were identified in whole blood samples from patients with sepsis or ARDS based on the Gene Expression Omnibus (GEO) datasets GSE32707, GSE54514 and GSE10361. Functional enrichment analysis explored the biological characteristics of differentially expressed genes. Genes with high functional connectivity based on a protein-protein interaction network were marked as hub genes, which were validated using the GEO dataset GSE76293, and a gene set variation analysis index (GSVA) was assigned. Diagnostic and predictive ability of the hub genes were assessed by receiver operating characteristic (ROC) curve analysis. DNA methylation levels of hub genes were quantified using the GEO dataset GSE67530.

Results

Forty-one differentially expressed genes were shared between sepsis-specific and ARDS-specific datasets. MAP2K2 and IRF7 functional activity was highly connected in sepsis-induced ARDS. Hub genes included RETN, MVP, DEFA4, CTSG, AZU1, FMNL1, RBBP7, POLD4, RIN3, IRF7. ROC curve analysis of the hub gene GSVA index showed good diagnostic ability in sepsis or ARDS. Among genes related to sepsis-induced ARDS, 17 were differentially methylated. Principal component analysis and heatmaps indicated that gene methylation patterns differed significantly between ARDS patients and controls.

Conclusion

We identified a genetic profile specific to early-stage sepsis-induced ARDS. The abnormal expression of these genes may be caused by hypomethylation, which may serve as a biomarker for early diagnosis of ARDS.

Decitabine Downregulates TIGAR to Induce Apoptosis and Autophagy in Myeloid Leukemia Cells

Decitabine (DAC) is a well-known DNA methyltransferase inhibitor, which has been widely used for the treatment of acute myeloid leukemia (AML). However, in addition to hypomethylation, DAC in AML is also involved in cell metabolism, apoptosis, and immunity. The TP53-induced glycolysis and apoptosis regulator (TIGAR) functions to inhabit glycolysis and protect cancer cells from reactive oxygen species- (ROS-) associated apoptosis. Our previous study revealed that TIGAR is highly expressed in myeloid leukemia cell lines and AML primary cells and associated with poor prognosis in adult patients with cytogenetically normal AML. In the present study, it was found that in a time- and concentration-dependent manner, DAC downregulates the TIGAR expression, induces ROS production, and promotes apoptosis in HL-60 and K562 cells. However, blocking the glycolytic pathway partially reversed the combined effects of DAC and TIGAR knockdown on apoptosis, ROS production, and cell cycle arrest, indicating that DAC induced apoptosis through the glycolytic pathway. Furthermore, TIGAR also has a negative impact on autophagy, while DAC treatment upregulates autophagy-related proteins LC3, Beclin-1, ATG3, and ATG-5, downregulates p62, and promotes the formation of autophagosomes, indicating that DAC may activate autophagy by downregulating TIGAR. Taken together, DAC plays an unmethylated role in inducing apoptosis and activating autophagy in myeloid leukemia by downregulating TIGAR.

Immune responses to azacytidine in animal models of inflammatory disorders: a systematic review

Inflammatory disorders like diabetes, systemic lupus erythematodes, inflammatory lung diseases, rheumatoid arthritis and multiple sclerosis, but also rejection of transplanted organs and GvHD, form a major burden of disease. Current classes of immune suppressive drugs to treat these disorders are never curative and side effects are common. Therefore there is a need for new drugs with improved and more targeted modes of action. Potential candidates are the DNA methyl transferase inhibitor 5-azacytidine (Aza) and its derivative 5-aza 2′deoxycitidine (DAC). Aza and DAC have been tested in several pre-clinical in vivo studies. In order to obtain an overview of disorders for which Aza and/or DAC can be a potential treatment, and to find out where information is lacking, we systematically reviewed pre-clinical animal studies assessing Aza or DAC as a potential therapy for distinct inflammatory disorders. Also, study quality and risk of bias was systematically assessed. In the 35 identified studies, we show that both Aza and DAC do not only seem to be able to alleviate a number of inflammatory disorders, but also prevent solid organ rejection and GvHD in in vivo pre-clinical animal models. Aza/DAC are known to upregulate FOXP3, a master transcription factor for Treg, in vitro. Seventeen studies described the effect on Treg, of which 16 studies showed an increase in Treg. Increasing Treg therefore seems to be a common mechanism in preventing inflammatory disorders by Aza/DAC. We also found, however, that many essential methodological details were poorly reported leading to an unclear risk of bias. Therefore, reported effects might be an overestimation of the true effect.

Penehyclidine hydrochloride alleviates lipopolysaccharide‑induced acute respiratory distress syndrome in cells via regulating autophagy‑related pathway

Acute progressive hypoxic respiratory failure caused by various predisposing factors is known as acute respiratory distress syndrome (ARDS). Although penehyclidine hydrochloride (PHC), an anticholinergic drug, is widely applied in clinical practice, the specific mechanisms underlying PHC in the treatment of ARDS are not completely understood. In the present study, BEAS-2B cells were treated with 10 ng/ml lipopolysaccharide (LPS) to establish an ARDS cell model and a rat model of acute lung injury (ALI). The influences of PHC and/or autophagy inhibitor (3-methyladenine (3-MA)) on the morphology, autophagy, proliferation and apoptosis of cells and tissues were evaluated using hematoxylin and eosin staining, Cell Counting Kit-8 assays, Hoechst staining, TUNEL staining, flow cytometry, immunofluorescence assays, ELISAs and scanning electron microscopy. The expression levels of apoptosis- and autophagy-related proteins were measured via western blotting. The results indicated that PHC enhanced proliferation and autophagy, and decreased apoptosis and the inflammatory response in LPS-induced BEAS-2B cells and ALI model rats. In addition, 3-MA reversed the effects of PHC on proliferation, inflammation, apoptosis and autophagy in LPS-induced BEAS-2B cells. Therefore, the present study suggested that PHC demonstrated a protective effect in LPS-induced ARDS by regulating an autophagy-related pathway.

Genomic responses of DNA methylation and transcript profiles in zebrafish cells upon nutrient deprivation stress

Environmental stress such as nutrient deprivation across multiple fields in nature causes physiological and biochemical changes in organism. Understanding the potential epigenetic modulations to phenotypic variation upon nutrient deprivation stress is crucial for environmental assessments. Here, the methyl-cytosine at single-base resolution was mapped across the whole genome and the methylation patterns and methylation levels coordinated with transcript analysis were systemically elaborated in zebrafish embryonic fibroblast cells under serum starvation stress. The down-regulated genes mainly annotated to the pathways of DNA replication and cell cycle that were consistent with cell physiological changes. Vast differentially methylated regions were identified in genomic chromosome and showed enrichment in the intron and intergenic regions. In an integrated transcriptome and DNA methylation analyses, 135 negatively correlated genes were determined, wherein the hub genes of gins2, cdca5, fbxo5, slc29a2, suv39h1b, and zgc:174160 were predominant responsive to the nutrient condition changes. Besides, nutrient recovery and DNA methyltransferases inhibitor supplements partly rescued cell proliferation with decrease of DNA methylation and reactivation of several depressed genes, implying the possible intrinsic relationships among cell physiological state, mRNA expression, and DNA methylation. Collectively, current study proved the broad role of DNA methylation in governing cellular responses to nutrient deprivation and revealed the epigenetic risk of starvation stress in zebrafish.

The Beneficial Effect of HES on Vascular Permeability and Its Relationship With Endothelial Glycocalyx and Intercellular Junction After Hemorrhagic Shock

Background

Vascular leakage is a common complication of hemorrhagic shock. Endothelial glycocalyx plays a crucial role in the protection of vascular endothelial barrier function. Hydroxyethyl starch (HES) is a commonly used resuscitation fluid for hemorrhagic shock. However, whether the protective effect of HES on vascular permeability after hemorrhagic shock is associated with the endothelial glycocalyx is unclear.

Methods

Using hemorrhagic shock rat model and hypoxia treated vascular endothelial cells (VECs), effects of HES (130/0.4) on pulmonary vascular permeability and the relationship to endothelial glycocalyx were observed.

Results

Pulmonary vascular permeability was significantly increased after hemorrhagic shock, as evidenced by the increased permeability of pulmonary vessels to albumin-fluorescein isothiocyanate conjugate (FITC-BSA) and Evans blue, the decreased transendothelial electrical resistance of VECs and the increased transmittance of FITC-BSA. The structure of the endothelial glycocalyx was destroyed, showing a decrease in thickness. The expression of heparan sulfate, hyaluronic acid, and chondroitin sulfate, the components of the endothelial glycocalyx, was significantly decreased. HES (130/0.4) significantly improved the vascular barrier function, recovered the thickness and the expression of components of the endothelial glycocalyx by down-regulating the expression of heparinase, hyaluronidase, and neuraminidase, and meanwhile increased the expression of intercellular junction proteins ZO-1, occludin, and VE-cadherin. Degradation of endothelial glycocalyx with degrading enzyme (heparinase, hyaluronidase, and neuraminidase) abolished the beneficial effect of HES on vascular permeability, but had no significant effect on the recovery of the expression of endothelial intercellular junction proteins induced by HES (130/0.4). HES (130/0.4) decreased the expression of cleaved-caspase-3 induced by hemorrhagic shock.

Conclusions

HES (130/0.4) has protective effect on vascular barrier function after hemorrgic shock.The mechanism is mainly related to the protective effect of HES on endothelial glycocalyx and intercellular junction proteins. The protective effect of HES on endothelial glycocalyx was associated with the down-regulated expression of heparinase, hyaluronidase, and neuraminidase. HES (130/0.4) had an anti-apoptotic effect in hemorrhagic shock.

Signaling pathways and clinical application of RASSF1A and SHOX2 in lung cancer

BACKGROUND

An increasing number of studies have focused on the early diagnostic value of the methylation of RASSF1A and SHOX2 in lung cancer. However, the intricate cellular events related to RASSF1A and SHOX2 in lung cancer are still a mystery. For researchers and clinicians aiming to more profoundly understand the diagnostic value of methylated RASSF1A and SHOX2 in lung cancer, this review will provide deeper insights into the molecular events of RASSF1A and SHOX2 in lung cancer.

METHODOLOGY

We searched for relevant publications in the PubMed and Google Scholar databases using the keywords "RASSF1A", "SHOX2" and "lung cancer" etc. First, we reviewed the RASSF1A and SHOX2 genes, from their family structures to the functions of their basic structural domains. Then we mainly focused on the roles of RASSF1A and SHOX2 in lung cancer, especially on their molecular events in recent decades. Finally, we compared the value of measuring RASSF1A and SHOX2 gene methylation with that of the common methods for the diagnosis of lung cancer patients.

RESULTS

The RASSF1A and SHOX2 genes were confirmed to be regulators or effectors of multiple cancer signaling pathways, driving tumorigenesis and lung cancer progression. The detection of RASSF1A and SHOX2 gene methylation has higher sensitivity and specificity than other commonly used methods for diagnosing lung cancer, especially in the early stage.

CONCLUSIONS

The RASSF1A and SHOX2 genes are critical for the processes of tumorigenesis, development, metastasis, drug resistance, and recurrence in lung cancer. The combined detection of RASSF1A and SHOX2 gene methylation was identified as an excellent method for the screening and surveillance of lung cancer that exhibits high sensitivity and specificity.

5-Aza-2'-deoxycytidine enhances lipopolysaccharide-induced inflammatory cytokine expression in human dental pulp cells by regulating TRAF6 methylation

Dental pulp inflammation is a common bacterially driven inflammation characterized by the local accumulation of inflammatory mediators in human dental pulp. DNA methylation is a crucial epigenetic modification that that plays a fundamental role in gene transcription, and its role in inflammation-related diseases has recently attracted attention. However, its role in dental pulp inflammation is poorly understood. This study is aimed to elucidate the role of DNA methylation in lipopolysaccharide (LPS)-induced inflammatory reaction in human dental pulp cells (hDPCs). hDPCs were pretreated with DNA methylation inhibitor 5-aza-2ʹ-deoxycytidine (5-Aza-CdR) and a cytokine antibody array was used to detect LPS-induced cytokine expression. The results indicated that 5-Aza-CdR significantly increased the expression of several pro-inflammatory cytokines in LPS-treated cells, including IL-6, IL-8, GM-CSF, MCP-2 and RANTES. The increased expression levels of IL-6 and IL-8 were further verified by qRT-PCR and ELISA. Furthermore, pretreatment with 5-Aza-CdR resulted in upregulation of p-IKKα/β, p-IκBα, p-p65 and p-ERK in the NK-κB and MAPK pathways. In addition, the 5mC level of the TRAF6 promoter was significantly decreased following 5-Aza-CdR pretreatment in the LPS-stimulated hDPCs. The findings indicate that 5-Aza-CdR significantly enhances the expression of proinflammatory cytokines and activates the NF-κB and MAPK signaling pathways by eliciting a decline in the 5mc level in the TRAF6 promoter in hDPCs, suggesting that DNA methylation may play an important role in dental pulp inflammation. This study highlights the important role of DNA methylation in the immunity defense of dental pulp infection.

Both UFH and NAH alleviate shedding of endothelial glycocalyx and coagulopathy in LPS-induced sepsis

Sepsis commonly progresses to disseminated intravascular coagulation and induces the activation of heparanase (HPA) and the shedding of endothelial glycocalyx constituents, including syndecan-1 (SDC-1) and heparan sulphate (HS). However, the degradation of glycocalyx and its association with coagulation disorders remains undetermined. The present study aimed to evaluate the effect of unfractionated heparin (UFH) and N-acetylheparin (NAH), which is a non-anticoagulant heparin derivative, on endothelial glycocalyx and coagulation function in a lipopolysaccharide (LPS)-induced sepsis rat model, and to compare the differences observed in coagulation function between UFH and NAH. Experimental rats were randomly assigned to four groups: Control; LPS; UFH + LPS; and NAH + LPS. Rats were administered UFH or NAH and subsequently, ~1 min later, administered LPS (10 mg/kg; intravenous). The blood and lung tissues of rats were collected 0.5, 2 and 6 h after LPS injection, and were used for subsequent analysis. The results demonstrated that HPA activity and SDC-1 and HS levels increased, and this increase was associated with inflammatory cytokines and coagulation/fibrinolysis markers in the sepsis rat model. Histopathological examination was performed, and the lung injury score and lung wet/dry ratio indicated that UFH and NAH also significantly improved lung tissue injury. The results of the ELISA analysis demonstrated that UFH and NAH treatment: i) significantly decreased the levels of inflammatory cytokines including tumor necrosis factor-α and interleukin-6; ii) inhibited HPA activity and protected the integrity of the glycocalyx, which was identified by decreased HS and SDC-1 levels; and iii) decreased the levels of prothrombin fragment 1+2, thrombin-antithrombin complex, and plasminogen activator inhibitor-1 and increased the levels of fibrinogen and antithrombin-III. Preconditioning with UFH decreased the plasma activated partial thromboplastin time. These results indicated that UFH and NAH may alleviate sepsis-induced coagulopathy, and this effect may have been due to an inhibition of HPA activity and decrease in the shedding of the endothelial glycocalyx.

DNA methyltransferase DNMT1 inhibits lipopolysaccharide‑induced inflammatory response in human dental pulp cells involving the methylation changes of IL‑6 and TRAF6

Dental pulp inflammation is a pathological process characterized by local lesions in dental pulp and the accumulation of inflammatory mediators. DNA methylation of cytosine residues is a key epigenetic modification that is essential for gene transcription, and plays pivotal roles in inflammatory reactions and immune responses. However, the function of cytosine DNA methylation in the innate immune defense against the inflammation of dental pulp is poorly understood. To investigate the effect of DNA methylation in inflamed dental pulp upon innate immune responses, expression levels of the DNA methyltransferases (DNMT1, DNMT3a and DNMT3b) in human dental pulp cells (hDPCs) after lipopolysaccharide (LPS) stimulation were evaluated by western blotting and reverse transcription‑quantitative (RT‑q) PCR. Only DNMT1 expression was decreased, while the transcription of inflammatory cytokines was increased. In the immune responses of LPS‑induced hDPCs, the results of RT‑qPCR and ELISA showed that DNMT1 knockdown promoted the production of the pro‑inflammatory cytokines, interleukin (IL)‑6 and IL‑8. Western blotting demonstrated that DNMT1 knockdown increased the phosphorylation levels of IKKα/β and p38 in the NF‑κB and MAPK signaling pathways, respectively. Furthermore, MeDIP and RT‑qPCR analysis demonstrated that the 5‑methylcytosine levels of the IL‑6 and TNF receptor‑associated factor 6 (TRAF6) promoters were significantly decreased in DNMT1‑deficient hDPCs. Taken together, these results indicated that the expression of DNMT1 was decreased after LPS stimulation in hDPCs. DNMT1 depletion increased LPS‑induced cytokine secretion, and activated NF‑κB and MAPK signaling; these mechanisms may involve the decreased methylation levels of the IL‑6 and TRAF6 gene promoters. This study emphasized the role of DNMT1‑dependent DNA methylation on the inflammation of LPS‑infected dental pulp and provides a new rationale for the investigation of the molecular mechanisms of inflamed dental pulps.

DNA methylation exploration for ARDS: a multi-omics and multi-microarray interrelated analysis

Background

Despite advances in clinical management, there are currently no novel therapeutic targets for acute respiratory distress syndrome (ARDS). DNA methylation, as a reversible process involved in the development and progression of many diseases, would be used as potential therapeutic targets to improve the treatment strategies of ARDS. However, the meaningful DNA methylation sites associated with ARDS still remain largely unknown. We sought to determine the difference in DNA methylation between ARDS patients and healthy participants, and simultaneously, the feasible DNA methylation markers for potential therapeutic targets were also explored.

Methods

Microarray data of human blood samples for ARDS and healthy participants up to June 2019 was searched in GEO database. The difference analyses between ARDS and healthy population were performed through limma R package, and furthermore, interrelated analyses of DNA methylation and transcript were accomplished by VennDiagram R package. Perl and sva R package were used to merge microarray data and decrease heterogeneities among different studies. The biological function of screened methylation sites and their regulating genes were annotated according to UniProt database and Pubmed database. GO term and KEGG pathway enrichment analyses were conducted using DAVID 6.8 and KOBAS 3.0. The meaningful DNA methylation markers to distinguish ARDS from healthy controls were explored through ROC (receiver operating characteristic curves) analyses.

Results

Five datasets in GEO databases (one DNA methylation dataset, three mRNA datasets, and one mRNA dataset of healthy people) were enrolled in present analyses finally, and the series were GSE32707, GSE66890, GSE10474, GSE61672, and GSE67530. These databases included 99 patients with ARDS (within 48 h of onset) and 136 healthy participants. Difference analyses indicated 44,439 DNA methylation alterations and 29 difference mRNAs between ARDS and healthy controls. 40 methylation variations regulated transcription of 16 genes was explored via interrelated analysis. According to the functional annotations, 30 DNA methylation sites were related to the imbalance of inflammation or immunity, endothelial function, epithelial function and/or coagulation function. cg03341377, cg24310395, cg07830557 and cg08418670, with AUC up to 0.99, might be the meaningful characteristics with the highest performance to distinguish ARDS from healthy controls.

Conclusions

44,439 DNA methylation alterations and 29 difference mRNAs exist between ARDS and healthy controls. 30 DNA methylation sites may regulate transcription of 10 genes, which take part in pathogenesis of ARDS. These findings could be intervention targets, with validation experiments to be warranted to assess these further.

MiR-150 attenuates LPS-induced acute lung injury via targeting AKT3

Acute lung injury (ALI) and its severe manifestation of acute respiratory distress syndrome (ARDS) in human lung are induced by inflammatory cytokines and endogenous factors such as miRNAs. However, the role of miR-150 in lipopolysaccharide (LPS)-induced ALI is not clear. Here, we found miR-150 expression was significantly reduced in the serum of patients with ARDS, and negatively associated with the disease severity and 28-day survival of ARDS. In vivo, miR-150 decreased total cell and neutrophil counts, and production of inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) as well as levels of total protein, albumin and IgM in the bronchoalveolar lavage (BAL) fluid in LPS-induced ALI mice. Meanwhile, miR-150 improved the 72 h survival rate of LPS-induced ALI mice. In-vitro assays demonstrated that miR-150 alleviated LPS-induced A549 cell apoptosis, autophagy, and release of inflammatory cytokines. Further, AKT3 was a direct target of miR-150. Silencing of AKT3 partially reversed LPS-induced A549 cell injury, and enhanced the protective effects of miR-150. In addition, miR-150 or si-AKT3 effectively inhibited the phosphorylation levels of c-Jun N-terminal kinase (JNK) and nuclear factor-κB (NF-κB) (p65 and IκBα). In conclusion, miR-150 alleviated LPS-induced acute lung injury via directly targeting AKT3 expression or regulating JNK and NF-κB pathways, which may be a promising therapeutic strategy to treat ALI/ARDS.

A Free Radical Scavenger Ameliorates Teratogenic Activity of a DNA Hypomethylating Hematological Therapeutic

The spin-trap free radical scavenger N-tert-butyl-α-phenylnitron (PBN) ameliorated effects of several teratogens involving reactive oxygen species (ROS). We investigated for the first time whether PBN could ameliorate teratogenesis induced by a DNA hypomethylating hematological therapeutic 5-azacytidine (5azaC). At days 12 and 13 of gestation, Fisher rat dams were pretreated by an i.v. injection of PBN (40 mg/kg) and 1 h later by an i.p. injection of 5azaC (5mg/kg). Development was analyzed at gestation day 15 in embryos and day 20 in fetuses. PBN alone did not significantly affect development. PBN pretreatment restored survival of 5azaC-treated dams' embryos to the control level, restored weight of embryos and partially of fetuses, and partially restored crown-rump lengths. PBN pretreatment converted limb adactyly to less severe oligodactyly. PBN pretreatment restored global DNA methylation level in the limb buds to the control level. Cell proliferation in limb buds of all 5azaC-treated dams remained significantly lower than in controls. In the embryonic liver, PBN pretreatment normalized proliferation diminished significantly by 5azaC; whereas in embryonic vertebral cartilage, proliferation of all 5azaC-treated dams was significantly higher than in PBN-treated dams or controls. Apoptotic indices significantly enhanced by 5azaC in liver and cartilage were not influenced by PBN pretreatment. However, PBN significantly diminished ROS or reactive nitrogen species markers nitrotyrosine and 8-hydroxy-2'deoxyguanosine elevated by 5azaC in embryonic tissues, and, therefore, activity of this DNA hypomethylating agent was associated to the activation of free radicals. That pretreatment with PBN enhanced proliferation in the liver and not in immature tissue is interesting for the treatment of 5azaC-induced hepatotoxicity and liver regeneration.

Relation between Red Cell Distribution Width and Mortality in Critically Ill Patients with Acute Respiratory Distress Syndrome

Background

Currently, evidence regarding the predictive significance of red blood cell distribution width (RDW) among patients with acute respiratory distress syndrome (ARDS) remains scarce. The aim of this study was to determine the prognostic value of RDW for critically ill patients with ARDS.

Methods

We studied all patients with ARDS from the Multiparameter Intelligent Monitoring in Intensive Care Database III (MIMIC-III) for whom RDW was available. The clinical outcomes were 30-day and 90-day mortality. Analyses included logistic multivariate regression model, Receiver Operating Characteristic (ROC) analysis, and subgroup analysis.

Results

A total of 404 eligible ARDS patients were included. After adjustment for several clinical characteristics related to 30-day mortality, the adjusted OR (95% CIs) for RDW levels ≥14.5% was 1.91 (1.08, 3.39). A similar trend was observed for 90-day mortality. The RDW levels ≥14.5% were also an independent predictor of 90-day mortality (OR, 2.56; 95% CI, 1.50 to 4.37; P = 0.0006) compared with the low RDW levels (<14.5%). In subgroup analyses, RDW showed no significant interactions with other relevant risk factors for 30-day mortality.

Conclusions

RDW appeared to be a novel, independent predictor of mortality in critically ill patients with ARDS.

MyD88 hypermethylation mediated by DNMT1 is associated with LTA-induced inflammatory response in human odontoblast-like cells

Dental caries is a chronic, infectious, and destructive disease that allows bacteria to break into the dental pulp tissue. As caries-related bacteria invade the human dentinal tubules, odontoblasts are the first line of dental pulp that trigger the initial inflammatory and immune responses. DNA methylation is a key epigenetic modification that plays a fundamental role in gene transcription, and its role in inflammation-related diseases has recently attracted attention. However, whether DNA methylation regulates the inflammatory response of human odontoblasts is still unknown. In the present study, we investigated the expression of DNA methyltransferase (DNMT)-1 in lipoteichoic acid (LTA)-stimulated human odontoblast-like cells (hOBs) and found that DNMT1 expression showed a decline that is contrary to the transcription of inflammatory cytokines. Knockdown of the DNMT1 gene increased the expression of several cytokines, including IL-6 and IL-8, in the LTA-induced inflammatory response. DNMT1 knockdown increased the phosphorylation of IKKα/β, IκBα, and p65 in the NF-κB pathway and the phosphorylation of p38 and ERK in the MAPK pathway; however, only the NF-κB pathway inhibitor PDTC suppressed both IL-6 and IL-8 expression, whereas inhibitors of the MAPK pathway (U0126, SB2035580, and SP600125) did not. Furthermore, DNMT1 knockdown upregulated the expression of MyD88 and TRAF6 but only attenuated the MyD88 gene promoter methylation in LTA-treated hOBs. Taken together, these results demonstrated that DNMT1 depletion caused hypomethylation and upregulation of MyD88, which resulted in activation of the NF-κB pathway and the subsequent release of LTA-induced inflammatory cytokines in hOBs. This study emphasizes the critical role of DNA methylation in the immune defense of odontoblasts when dental pulp reacted to caries.

Anti-inflammatory activity of triazine derivatives: A systematic review

Triazines are heterocyclic compounds with a variety of biological activities that have been increasingly studied in recent years due to their versatile structure (three isoforms) and the different derivatives that can be synthesized from them to ensure functional motifs. This systematic review provides the evidence in the literature of the in vitro and in vivo anti-inflammatory activity of triazine derivatives from 2008 to June 2018. Four bibliographical databases were consulted (PubMed, Web of Science, EMBASE and Scopus), and a total of 48 studies were included in this paper based on our eligibility criteria. Although 35.17% of evaluated triazines were demonstrated to be promising anti-inflammatory agents, further studies need to be conducted to explore their pharmacological profiles in the medical research of drug discovery to control the risk factors and pathophysiology of several chronic inflammation-based diseases.

Suppression of SUN2 by DNA methylation is associated with HSCs activation and hepatic fibrosis

Hepatic myofibroblasts, activated hepatic stellate cells (HSCs), are the main cell type of extracellular matrix (ECM) deposition during hepatic fibrosis. Aberrant DNA methylation-regulated HSCs activation in liver fibrogenesis has been reported, but the functional roles and mechanisms of DNA methylation in hepatic fibrosis remain to be elucidated. In the present study, reduced representation bisulfite sequencing (RRBS) analysis of primary HSCs revealed hypermethylation patterns in hepatic fibrosis. Interestingly, we found SAD1/UNC84 domain protein-2 (SUN2) gene hypermethylation at CpG sites during liver fibrogenesis in mice with CCl4-induced hepatic fibrosis, which was accompanied by low expression of SUN2. In vivo overexpression of SUN2 following adeno-associated virus-9 (AAV9) administration inhibited CCl4-induced liver injury and reduced fibrogenesis marker expression. Consistently, in vitro experiments showed that enforced expression of SUN2 suppressed HSCs activation and exerted anti-fibrogenesis effects in TGF-β1-activated HSC-T6 cells. In addition, the signaling mechanisms related to SUN2 expression were investigated in vivo and in vitro. Methyltransferase-3b (DNMT3b) is the principal regulator of SUN2 expression. Mechanistically, inhibition of protein kinase B (AKT) phosphorylation may be a crucial pathway for SUN2-mediated HSCs activation. In conclusion, these findings provide substantial new insights into SUN2 in hepatic fibrosis.

Casein glycomacropeptide hydrolysates inhibit PGE2 production and COX2 expression in LPS-stimulated RAW 264.7 macrophage cells via Akt mediated NF-κB and MAPK pathways

A casein glycomacropeptide hydrolysate (GMPH) was found to possess inhibitory activity against lipopolysaccharide (LPS)-induced inflammatory response in our previous study. In the current study, the inhibitory effect and the underlying molecular mechanism of GMPH on inflammatory response in LPS-stimulated RAW264.7 macrophages were further investigated. Results showed that GMPH significantly suppressed LPS-induced intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) production. GMPH reduced the production of prostaglandin E2 (PEG2) and the expression of cyclooxygenase-2 (COX-2) and cytosolic phospholipase A2 (cPLA2) in LPS-stimulated macrophages. GMPH also attenuated LPS-induced phosphorylation of MAPK (c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38) and protein kinase B (Akt). Furthermore, GMPH inhibited nuclear transcription factor kappa-B (NF-κB) activation by suppressing the nuclear translocation of NF-κB p65, which was markedly reversed by LY294002, an Akt inhibitor. These results demonstrated that GMPH exerts anti-inflammatory functions through the inactivation of MAPK and Akt in LPS-stimulated RAW264.7 macrophages, therefore may hold potential to ameliorate inflammation-related metabolic disorders.

6% Hydroxyethyl starch (HES 130/0.4) diminishes glycocalyx degradation and decreases vascular permeability during systemic and pulmonary inflammation in mice

Background

Increased vascular permeability is a pathophysiological hallmark of sepsis and results in increased transcapillary leakage of plasma fluid, hypovolemia, and interstitial edema formation. 6% hydroxyethyl starch (HES 130/0.4) is commonly used to treat hypovolemia to maintain adequate organ perfusion and oxygen delivery. The present study was designed to investigate the effects of 6% HES 130/0.4 on glycocalyx integrity and vascular permeability in lipopolysaccharide (LPS)-induced pulmonary inflammation and systemic inflammation in mice.

Methods

6% HES 130/0.4 or a balanced electrolyte solution (20 ml/kg) was administered intravenously 1 h after cecal ligation and puncture (CLP) or LPS inhalation. Sham-treated animals receiving 6% HES 130/0.4 or the electrolyte solution served as controls. The thickness of the endovascular glycocalyx was visualized by intravital microscopy in lung (LPS inhalation model) or cremaster muscle (CLP model). Syndecan-1, hyaluronic acid, and heparanase levels were measured in blood samples. Vascular permeability in the lungs, liver, kidney, and brain was measured by Evans blue extravasation.

Results

Both CLP induction and LPS inhalation resulted in increased vascular permeability in the lung, liver, kidney, and brain. 6% HES 130/0.4 infusion led to significantly reduced plasma levels of syndecan-1, heparanase, and hyaluronic acid, which was accompanied by a preservation of the glycocalyx thickness in postcapillary venules of the cremaster (0.78 ± 0.09 μm vs. 1.39 ± 0.10 μm) and lung capillaries (0.81 ± 0.09 μm vs. 1.49 ± 0.12 μm).

Conclusions

These data suggest that 6% HES 130/0.4 exerts protective effects on glycocalyx integrity and attenuates the increase of vascular permeability during systemic inflammation.

Electronic supplementary material

The online version of this article (doi: 10.1186/s13054-017-1846-3) contains supplementary material, which is available to authorized users.

Modulation of mitogen‑activated protein kinase attenuates sepsis‑induced acute lung injury in acute respiratory distress syndrome rats

Sepsis is the most important predisposing cause inducing acute respiratory distress syndrome (ARDS); however, the mechanism of sepsis leading to the development of ARDS remains to be elucidated. Suppression of the mitogen‑activated protein kinase (MAPK) signal by blocking the phosphorylation of Jun N‑terminal kinase (JNK) and p38 in lung tissues could alleviate acute lung injury induced by sepsis. MAPK signaling may have a crucial role in development of the sepsis‑induced acute lung injury. The specific inhibitors of JNK and p38 MAPK, SP600125 and SB203580, were administrated by intragastric injection 4 h before induction of ARDS after cecal ligation and puncture (CLP). Rats were sacrificed at 1, 6 or 24 h after CLP challenge. The histological evaluation, lung water content, and biochemical analysis were performed. The results revealed that the JNK and p38 MAPK inhibitor improved lung permeability, attenuated system inflammation, further alleviated the lung injury induced by sepsis. In conclusion, JNK and p38 MAPK signaling are essential for the development of ARDS following sepsis. Further studies are needed to illuminate the detailed mechanisms of JNK and p38 MAPK signaling in sepsis‑induced ARDS.

Sulodexide recovers endothelial function through reconstructing glycocalyx in the balloon-injury rat carotid artery model

Disruption of endothelial cell function is a principle event in cardiovascular disease. Accordingly, therapies have mostly focused on repairing the endothelium, but little attention has been paid to the reconstruction of glycocalyx, which covers the endothelium and protects the function of endothelial cells. Sulodexide has a similar glycosaminoglycan structure to glycocalyx, so it is assumed to be effective in remodeling the glycocalyx following damage. We assessed the effect of sulodexide on glycocalyx remodeling and endothelial function in the balloon-injury rat carotid artery model. Electron micrographs showed that sulodexide (2mg/kg, administered by intraperitoneal injection for seven days after injury) could reconstruct the endothelial glycocalyx and recover the clear cytoarchitecture. With regard to endothelial function, sulodexide increased endothelial nitric oxide synthase level, attenuated endothelial hyperplasia, and inhibited platelet aggregation that benefitted from glycocalyx reforming. Sulodexide decreased the glycocalyx damage related expression of CD31 and intercellular cell adhesion molecule-1 in endothelium, accompanying by the downregulation of leukocyte counts and C-reactive protein levels. The levels of the atherosclerosis-related factors, osteopontin and vascular cell adhesion molecule-1, which increased in activated endothelial cells lacking glycocalyx, were normalized by sulodexide. Along with the benefit of glycocalyx reconstruction, sulodexide reversed the dyslipidemia. Moreover, sulodexide prevented CD68-positive inflammatory cells infiltration into the vascular wall, presumably as a result of glycocalyx reconstruction. In summary, sulodexide treatment reconstructed glycocalyx which therefore preserved endothelial function and attenuated the expression of inflammatory factors, and decreased the blood coagulation and lipid metabolism, all of which are important for vascular healing.