Different changes in mitochondrial apoptotic pathway in lymphocytes and granulocytes in cirrhotic patients with sepsis

Forsythiaside A alleviates acute lung injury via the RNF99/TRAF6/NF-κB signaling pathway

The aim of this study was to investigated the effects of forsythiaside A (FA) on acute lung injury (ALI). The lung tissue pathological was detected by hematoxylin-eosin staining (HE) staining. Wet weight/dry weight (w/d) of the lung in mice was measured. Cytokine such as interleukin 1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) were also detected. Compared with the vector group, the protein expression levels of TRAF6 and TAK1 the RNF99 group were significantly reduced. Ubiquitinated TRAF6 protein was increased after knockdown of RNF99. Finally, it was found that FA significantly ameliorated ALI via regulation of RNF99/TRAF6/NF-κB signal pathway. In conclusion, RNF99 was an important biomarker in ALI and FA alleviated ALI via RNF99/ TRAF6/NF-κB signal pathway.

MiR-15b-5p and PCSK9 inhibition reduces lipopolysaccharide-induced endothelial dysfunction by targeting SIRT4

BACKGROUND

Endothelial dysfunction and deregulated microRNAs (miRNAs) participate in the development of sepsis and are associated with septic organ failure and death. Here, we explored the role of miR-15b-5p on inflammatory pathways in lipopolysaccharide (LPS)-treated human endothelial cells, HUVEC and TeloHAEC.

METHODS

The miR-15b-5p levels were evaluated in LPS-stimulated HUVEC and TeloHAEC cells by quantitative real-time PCR (qRT-PCR). Functional experiments using cell counting kit-8 (CCK-8), transfection with antagomir, and enzyme-linked immunosorbent assays (ELISA) were conducted, along with investigation of pyroptosis, apoptosis, autophagy, and mitochondrial reactive oxygen species (ROS) by cytofluorometric analysis and verified by fluorescence microscopy. Sirtuin 4 (SIRT4) levels were detected by ELISA and immunoblotting, while proprotein convertase subtilisin-kexin type 9 (PCSK9) expression was determined by flow cytometry (FACS) and immunofluorescence analyses. Dual-luciferase reporter evaluation was performed to confirm the miR-15b-5p-SIRT4 interaction.

RESULTS

The results showed a correlation among miR-15b-5p, PCSK9, and SIRT4 levels in septic HUVEC and TeloHAEC. Inhibition of miR-15b-5p upregulated SIRT4 content, alleviated sepsis-related inflammatory pathways, attenuated mitochondrial stress, and prevented apoptosis, pyroptosis, and autophagic mechanisms. Finally, a PCSK9 inhibitor (i-PCSK9) was used to analyze the involvement of PCSK9 in septic endothelial injury. i-PCSK9 treatment increased SIRT4 protein levels, opposed the septic inflammatory cascade leading to pyroptosis and autophagy, and strengthened the protective role of miR-15b-5p inhibition. Increased luciferase signal validated the miR-15b-5p-SIRT4 binding.

CONCLUSIONS

Our in vitro findings suggested the miR-15b-5p-SIRT4 axis as a suitable target for LPS-induced inflammatory pathways occurring in sepsis, and provide additional knowledge on the beneficial effect of i-PCSK9 in preventing vascular damage by targeting SIRT4.

Identification of potential biomarkers and pathways for sepsis using RNA sequencing technology and bioinformatic analysis

Long non-coding RNAs (lncRNAs) has been proven by many to play a crucial part in the process of sepsis. To obtain a better understanding of sepsis, the molecular biomarkers associated with it, and its possible pathogenesis, we obtained data from RNA-sequencing analysis using serum from three sepsis patients and three healthy controls (HCs). Using edgeR (one of the Bioconductor software package), we identified 1118 differentially expressed mRNAs (DEmRNAs) and 1394 differentially expressed long noncoding RNAs (DElncRNAs) between sepsis patients and HCs. We identified the biological functions of these disordered genes using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analyses. The GO analysis showed that the homophilic cell adhesion via plasma membrane adhesion molecules was the most significantly enriched category. The KEGG signaling pathway analysis indicated that the differentially expressed genes (DEGs) were most significantly enriched in retrograde endocannabinoid signaling. Using STRING, a protein-protein interaction network was also created, and Cytohubba was used to determine the top 10 hub genes. To examine the relationship between the hub genes and sepsis, we examined three datasets relevant to sepsis that were found in the gene expression omnibus (GEO) database. PTEN and HIST2H2BE were recognized as hub gene in both GSE4607, GSE26378, and GSE9692 datasets. The receiver operating characteristic (ROC) curves indicate that PTEN and HIST2H2BE have good diagnostic value for sepsis. In conclusion, this two hub genes may be biomarkers for the early diagnosis of sepsis, our findings should deepen our understanding of the pathogenesis of sepsis.

Association between blood caspase-9 concentrations and septic patient prognosis

BACKGROUND

There are few data on caspase‑9 (intrinsic apoptosis pathway initiating caspase) in septic patients. Higher serum caspase‑9 levels in septic patients than in healthy subjects have been found. However, there are no data on the prognosis of septic patients and blood caspase‑9 concentrations. Therefore, the objective of this study was to analyze the potential association between blood caspase‑9 concentrations and prognosis in septic patients.

METHODS

Three Spanish hospitals participated in the recruitment of septic patients admitted to intensive care units in this observational and prospective study. Serum caspase‑9 concentrations were determined at the time of sepsis diagnosis. The 30-day mortality was the outcome variable.

RESULTS

Higher Acute Phisiology and Chronic Health Evaluation(APACHE)-II (p < 0.001), Sepsis-related Organ Failure Assessment score (SOFA) (p < 0.001), serum lactic acid levels (p = 0.001), serum caspase‑9 levels (p < 0.001), age (p < 0.001), International normalized ratio (INR) (p = 0.001), rate of septic shock (p = 0.001), Activated partial thromboplastin time (aPTT) (p = 0.03), rate of diabetes mellitus (p = 0.04), and lower platelet counts (p = 0.01) were found in non-surviving (n = 80) than in surviving patients (n = 134). Multiple logistic regression analysis showed an association between serum caspase‑9 concentrations and mortality (Odds Ratio (OR) = 1.985; 95% Confidence Interval (CI) = 1.359-2.900; p < 0.001) regardless of age, SOFA, lactic acid and septic shock and history of diabetes mellitus. No significant differences were found when we compared area under ROC curves of serum caspase‑9 with SOFA (p = 0.92) and with lactic acid (p = 0.59).

CONCLUSIONS

The main novel finding of our study was the association between blood caspase‑9 concentrations and septic patient prognosis. However, our study showed some limitations (for example, the absence of data in respect to execution of Surviving Sepsis Campaign bundles); thus, more research could be interesting to confirm our preliminary findings.

Pathophysiology of Sepsis and Genesis of Septic Shock: The Critical Role of Mesenchymal Stem Cells (MSCs)

The treatment of sepsis and septic shock remains a major public health issue due to the associated morbidity and mortality. Despite an improvement in the understanding of the physiological and pathological mechanisms underlying its genesis and a growing number of studies exploring an even higher range of targeted therapies, no significant clinical progress has emerged in the past decade. In this context, mesenchymal stem cells (MSCs) appear more and more as an attractive approach for cell therapy both in experimental and clinical models. Pre-clinical data suggest a cornerstone role of these cells and their secretome in the control of the host immune response. Host-derived factors released from infected cells (i.e., alarmins, HMGB1, ATP, DNA) as well as pathogen-associated molecular patterns (e.g., LPS, peptidoglycans) can activate MSCs located in the parenchyma and around vessels to upregulate the expression of cytokines/chemokines and growth factors that influence, respectively, immune cell recruitment and stem cell mobilization. However, the way in which MSCs exert their beneficial effects in terms of survival and control of inflammation in septic states remains unclear. This review presents the interactions identified between MSCs and mediators of immunity and tissue repair in sepsis. We also propose paradigms related to the plausible roles of MSCs in the process of sepsis and septic shock. Finally, we offer a presentation of experimental and clinical studies and open the way to innovative avenues of research involving MSCs from a prognostic, diagnostic, and therapeutic point of view in sepsis.

Diallyl trisulfide plays an antifibrotic role by inhibiting the expression of Bcl‐2 in hepatic stellate cells

Hepatic fibrosis is an important early stage in the evolution of liver cirrhosis, and specific medicine and therapeutic measures are unavailable to date. Hepatic stellate cells (HSCs) are the main cells involved in the formation of hepatic fibrosis, and induction of the apoptosis of HSCs is an important strategy for the treatment of hepatic fibrosis. Diallyl trisulfide (DATS) is a natural product and is the main active ingredient in garlic. However, the exact molecular mechanisms underlying HSC apoptosis induced by DATS are not well understood. This study aimed to analyze the efficiency and mechanism of DATS in hepatic fibrosis. Different concentrations (25, 50, 100, and 200 μM) of DATS were used to treat HSCs. Changes in cell morphology and formation of apoptotic bodies were observed under an inverted microscope and an electric microscope. Bcl‐2 signaling involving Bax, Caspase‐3, Caspase‐6, Caspase‐8, Caspase‐9, p53, Apaf‐1, and Cyto‐c in fibrosis were examined, which is a critical step in the evaluation of antihepatic fibrosis agents. We also evaluated the effect of DATS on the cellular morphology of HSCs and apoptosis‐related factors under different Bcl‐2 expression states. Our results suggest that DATS regulates hepatic fibrosis by blocking the Bcl‐2 signaling pathway and upregulating the Bax/Bcl‐2 ratio.

Thymoquinone modulates the expression of sepsis‑related microRNAs in a CLP model

Sepsis is a clinical syndrome common in critical care settings. In the present study, the therapeutic effect of thymoquinone (TQ) on the expression of sepsis-related microRNAs (miRNAs/miRs), levels of inflammatory markers, organ dysfunction and mortality were investigated in a cecal ligation and puncture (CLP) rat model. A single dose of TQ (1 mg/kg) was administered to animals 24 h after CLP and the mortality rate was assessed up to 7 days following the induction of sepsis. In addition, blood samples were collected at different time points and the expression levels of miRNAs (i.e. miR-16, miR-21, miR-27a and miR-34a) were examined, along with the levels of inflammatory cytokines (i.e. TNF-α, IL-1α, IL-2, IL-6 and IL-10) and sepsis markers (i.e. C-reactive protein, endothelial cell-specific molecule-1, VEGF, procalcitonin and D-dimer). Liver, kidney and lung tissues were also collected for further histological examination. Treatment with TQ significantly downregulated the miRNA expression levels, as well as the levels of inflammatory cytokines and early-stage sepsis biomarkers by 30-70% at 12-36 h (P<0.05). Furthermore, CLP model rats treated with TQ exhibited an ~80% increase in survival rate compared with that in the untreated CLP group. In addition, TQ induced the preservation of organ function and structure. In conclusion, the present study demonstrated a promising therapeutic effect of TQ against the sequelae of sepsis.

Blood Bcl-2 levels to predict the mortality of septic patients

Aim: To determine whether blood concentrations of Bcl-2 during the 1st week of sepsis could help predict mortality. Methods: Serum Bcl-2 concentrations were determined at the 1st, 4th and 8th days of sepsis diagnosis. Results: Thirty-day surviving patients (n = 168) showed higher serum Bcl-2 levels at the 1st (p = 0.002), 4th (p < 0.001) and 8th days (p < 0.001) of sepsis diagnosis than non-surviving patients (n = 91). An association between serum Bcl-2 concentrations at the 1st (p = 0.003), 4th (p < 0.001) and 8th days (p = 0.01) and 30-day mortality after controlling for diabetes mellitus, Sepsis-related Organ Failure Assessment, lactic acid and age was found in the multiple logistic regression analysis. Conclusions: The novel finding is that blood Bcl-2 concentrations at any time in the 1st week of sepsis are associated with mortality.

Circulating Bcl-2 concentrations and septic patient mortality

INTRODUCTION

There are not data on blood B-cell lymphoma 2 (Bcl-2) concentrations (one of the antiapoptotic molecules of the Bcl-2 family in the intrinsic apoptosis pathway) in septic patients. Therefore, this study was carried with the aims to explore whether blood Bcl-2 concentrations at diagnosis of sepsis are different in survivor and non-survivor septic patients, are associated with mortality, and are useful for the mortality prediction.

METHODS

Intensive Care Units from 3 Spanish hospitals participated in this observational and prospective study with septic patients and serum Bcl-2 concentrations at diagnosis of sepsis were determined. Mortality at 30 days was as outcome variable.

RESULTS

We found that 30-day non-surviving patients (n=81) showed lower serum Bcl-2 levels (p=0.003) than surviving patients (n=140). We found that serum concentrations of Bcl-2<4.4ng/mL were associated with mortality (OR=3.228; 95% CI=1.406-7.415; p=0.006) in the multiple logistic regression analysis, and that showed an area under the curve for mortality prediction of 62% (95% CI=55-68%; p=0.003).

CONCLUSIONS

In our study appears novel findings such as higher blood Bcl-2 concentrations in survivor than in non-survivor septic patients, the association between low blood Bcl-2 concentrations and mortality of septic patients, and the ability of blood Bcl-2 concentrations for the prediction of septic patient mortality.

MicroRNAs and Sepsis-Induced Cardiac Dysfunction: A Systematic Review

Sepsis is a severe condition characterized by systemic inflammation. One of the most involved organs in sepsis is the heart. On the other hand, heart failure and dysfunction are some of the most leading causes of death in septic patients. miRNAs are short single-strand non-coding ribonucleic acids involved in the regulation of gene expression on a post-transcriptional phase, which means they are a part of the epigenetic process. Recently, researchers have found that miRNA expression in tissues and blood differs depending on different conditions. Because of this property, their use as serum sepsis biomarkers has also been explored. A narrative review is carried out to gather and summarize what is known about miRNAs' influence on cardiac dysfunction during sepsis. When reviewing the literature, we found at least 77 miRNAs involved in cardiac inflammation and dysfunction during sepsis. In the future, miRNAs may be used as early sepsis-induced cardiac dysfunction biomarkers or as new drug targets. This could help clinicians to early detect, prevent, and treat cardiac damage. The potential role of miRNAs as new diagnostic tools and therapeutic strategies worth deepening the complex network between non-coding RNA and biological pathways. Additional studies are needed to further investigate their role in sepsis-induced myocardium injury.

Identification and Validation of Potential miRNAs, as Biomarkers for Sepsis and Associated Lung Injury: A Network-Based Approach

Sepsis is a dysregulated immune response disease affecting millions worldwide. Delayed diagnosis, poor prognosis, and disease heterogeneity make its treatment ineffective. miRNAs are imposingly involved in personalized medicine such as therapeutics, due to their high sensitivity and accuracy. Our study aimed to reveal the biomarkers that may be involved in the dysregulated immune response in sepsis and lung injury using a computational approach and in vivo validation studies. A sepsis miRNA Gene Expression Omnibus (GEO) dataset based on the former analysis of blood samples was used to identify differentially expressed miRNAs (DEMs) and associated hub genes. Sepsis-associated genes from the Comparative Toxicogenomics Database (CTD) that overlapped with identified DEM targets were utilized for network construction. In total, 317 genes were found to be regulated by 10 DEMs (three upregulated, namely miR-4634, miR-4638-5p, and miR-4769-5p, and seven downregulated, namely miR-4299, miR-451a, miR181a-2-3p, miR-16-5p, miR-5704, miR-144-3p, and miR-1290). Overall hub genes (HIP1, GJC1, MDM4, IL6R, and ERC1) and for miR-16-5p (SYNRG, TNRC6B, and LAMTOR3) were identified based on centrality measures (degree, betweenness, and closeness). In vivo validation of miRNAs in lung tissue showed significantly downregulated expression of miR-16-5p corroborating with our computational findings, whereas expression of miR-181a-2-3p and miR-451a were found to be upregulated in contrast to the computational approach. In conclusion, the differential expression pattern of miRNAs and hub genes reported in this study may help to unravel many unexplored regulatory pathways, leading to the identification of critical molecular targets for increased prognosis, diagnosis, and drug efficacy in sepsis and associated organ injuries.

Non-coding RNAs and Exosomes: Their Role in the Pathogenesis of Sepsis

Sepsis is characterized as an uncontrolled host response to infection, and it represents a serious health challenge, causing excess mortality and morbidity worldwide. The discovery of sepsis-related epigenetic and molecular mechanisms could result in improved diagnostic and therapeutic approaches, leading to a reduced overall risk for affected patients. Accumulating data show that microRNAs, non-coding RNAs, and exosomes could all be considered as novel diagnostic markers for sepsis patients. These biomarkers have been demonstrated to be involved in regulation of sepsis pathophysiology. However, epigenetic modifications have not yet been widely reported in actual clinical settings, and further investigation is required to determine their importance in intensive care patients. Further studies should be carried out to explore tissue-specific or organ-specific epigenetic RNA-based biomarkers and their therapeutic potential in sepsis patients.

MicroRNA-34a Inhibition Alleviates Lung Injury in Cecal Ligation and Puncture Induced Septic Mice

Sepsis is the leading cause of death in intensive care units. MicroRNA-34a (miR-34a) is involved in sepsis progression, while its underlying mechanisms on sepsis-induced lung injury remain obscure. Oxidative stress, pyroptosis, and inhibition of autophagy can result in organ injury. MiR-34a has been reported to regulate oxidative stress and autophagy via inhibiting silent information regulator T1 (SIRT1) and autophagy gene 4B (ATG4B) signaling. This study aimed at identifying the function of miR-34a in oxidative stress, inflammation, pyroptosis, and autophagy in sepsis-induced lung injury. Male 8-week-old C57BL/6 mice were subjected to cecal ligation and puncture and treated with miR-34a antagomir/agomir. Survival (n = 10), histopathological changes (n = 6), and lung wet-to-dry ratio (n = 6) were recorded and assayed. Other detection (n = 6) was performed to investigate the level of oxidative stress, inflammation, pyroptosis, and autophagy in lung tissues. Results showed that miR-34a down-regulation ameliorated lung injury in septic mice as reflected by decreased lung injury scores (decrease from 3.00 ± 0.32 to 2.00 ± 0.32) and wet-to-dry ratio (0.36-fold decrease). MiR-34a down-regulation also decreased reactive oxygen species accumulation (0.36-fold decrease), and promoted superoxide dismutase activity and the expression of SIRT1 (1.24-fold increase), heme oxygenase-1 and nuclear factor erythroid 2 like 2 to inhibit oxidative stress in septic mice. Moreover, miR-34a down-regulation suppressed inflammatory response and pyroptosis in septic mice, as evidenced by decreased level of pro-inflammatory factors including tumor necrosis factor α, interleukin-6 (IL-6), IL-1β, and IL-18, activity of caspase-1 (0.51-fold decrease) and expression of nucleotide-binding domain and leucine-rich repeat protein-3 (0.48-fold decrease), apoptosis-associated speck-like protein containing a CARD, cleaved-caspase-1, and cleaved-gasdermin D (0.36-fold decrease), and increased level of anti-inflammatory factors IL-10. MiR-34a down-regulation also enhanced autophagy in septic mice as evidenced by more autolysosomes and elevated expressions of ATG4B (0.90-fold increase), beclin1, ATG9, and LC3 II/I. Among these experiments, miR-34a up-regulation showed opposite effects on oxidative stress, inflammatory response, pyroptosis, and autophagy in septic mice. Additionally, miR-34a could bind to the 3′-untranslated region of SIRT1 and ATG4B. In conclusion, our findings demonstrated that miR-34a was implicated in oxidative stress, inflammation, pyroptosis, and autophagy in the development of sepsis. MiR-34a inhibition had a potential to alleviate sepsis-induced lung injury.

Circulating Bcl-2 concentrations and septic patient mortality

INTRODUCTION

There are not data on blood B-cell lymphoma 2 (Bcl-2) concentrations (one of the antiapoptotic molecules of the Bcl-2 family in the intrinsic apoptosis pathway) in septic patients. Therefore, this study was carried with the aims to explore whether blood Bcl-2 concentrations at diagnosis of sepsis are different in survivor and non-survivor septic patients, are associated with mortality, and are useful for the mortality prediction.

METHODS

Intensive Care Units from 3 Spanish hospitals participated in this observational and prospective study with septic patients and serum Bcl-2 concentrations at diagnosis of sepsis were determined. Mortality at 30 days was as outcome variable.

RESULTS

We found that 30-day non-surviving patients (n=81) showed lower serum Bcl-2 levels (p=0.003) than surviving patients (n=140). We found that serum concentrations of Bcl-2<4.4ng/mL were associated with mortality (OR=3.228; 95% CI=1.406-7.415; p=0.006) in the multiple logistic regression analysis, and that showed an area under the curve for mortality prediction of 62% (95% CI=55-68%; p=0.003).

CONCLUSIONS

In our study appears novel findings such as higher blood Bcl-2 concentrations in survivor than in non-survivor septic patients, the association between low blood Bcl-2 concentrations and mortality of septic patients, and the ability of blood Bcl-2 concentrations for the prediction of septic patient mortality.

Epigenetic biomarkers for human sepsis and septic shock: insights from immunosuppression

Sepsis is a life-threatening condition that occurs when the body responds to an infection damaging its own tissues. Sepsis survivors sometimes suffer from immunosuppression increasing the risk of death. To our best knowledge, there is no 'gold standard' for defining immunosuppression except for a composite clinical end point. As the immune system is exposed to epigenetic changes during and after sepsis, research that focuses on identifying new biomarkers to detect septic patients with immunoparalysis could offer new epigenetic-based strategies to predict short- and long-term pathological events related to this life-threatening state. This review describes the most relevant epigenetic mechanisms underlying alterations in the innate and adaptive immune responses described in sepsis and septic shock, and their consequences for immunosuppression states, providing several candidates to become epigenetic biomarkers that could improve sepsis management and help predict immunosuppression in postseptic patients.

Elevated circulating lnc-ANRIL/miR-125a axis level predicts higher risk, more severe disease condition, and worse prognosis of sepsis

AIM

This study aimed to investigate the correlation of lnc-ANRIL/miR-125a axis with risk, severity, inflammation, and prognosis of sepsis.

METHODS

A hundred and twenty-six sepsis patients and 125 healthy controls were recruited, and then, blood samples were collected, and plasma was separated for lnc-ANRIL, miR-125a, lnc-ANRIL/miR-125a axis, and inflammatory cytokine level detections. In addition, basic characteristics, 28-day mortality, and accumulating survival of sepsis patients were recorded.

RESULTS

Plasma lnc-ANRIL expression was increased, miR-125a expression was decreased, and lnc-ANRIL/miR-125a axis level was elevated in sepsis patients compared with healthy controls, and all of them had good value for predicting sepsis risk with AUCs of 0.800, 0.817, and 0.843, respectively. Lnc-ANRIL and lnc-ANRIL/miR-125a axis were positively correlated with biochemical index levels including CRP and PCT levels, disease severity scale scores, and pro-inflammatory cytokine levels in sepsis patients, while miR-125a displayed the opposite trend. Lnc-ANRIL and lnc-ANRIL/miR-125a axis expressions were elevated, while miR-125a expression was declined in deaths compared with survivors, and all of them predicted 28-day mortality in sepsis patients with AUCs of 0.765, 0.745, and 0.785, respectively. Subsequently, the Kaplan-Meier analysis revealed that patients with high lnc-ANRIL, low miR-125a, and high lnc-ANRIL/miR-125a axis levels presented with worse accumulating survival. In addition, multivariate regression model analyses revealed that high plasma lnc-ANRIL/miR-125a axis was an independent predictive factor for both increased 28-day mortality and worse accumulating survival.

CONCLUSION

Circulating lnc-ANRIL/miR-125a axis was upregulated and could serve as a biomarker for severity, inflammation, and prognosis in sepsis patients.

MicroRNAs 143 and 150 in whole blood enable detection of T-cell immunoparalysis in sepsis

Background

Currently, no suitable clinical marker for detection of septic immunosuppression is available. We aimed at identifying microRNAs that could serve as biomarkers of T-cell mediated immunoparalysis in sepsis.

Methods

RNA was isolated from purified T-cells or from whole blood cells obtained from septic patients and healthy volunteers. Differentially regulated miRNAs were identified by miRNA Microarray (n = 7). Validation was performed via qPCR (n = 31).

Results

T-cells of septic patients revealed characteristics of immunosuppression: Pro-inflammatory miR-150 and miR-342 were downregulated, whereas anti-inflammatory miR-15a, miR-16, miR-93, miR-143, miR-223 and miR-424 were upregulated. Assessment of T-cell effector status showed significantly reduced mRNA-levels of IL2, IL7R and ICOS, and increased levels of IL4, IL10 and TGF-β. The individual extent of immunosuppression differed markedly. MicroRNA-143, − 150 and − 223 independently indicated T-cell immunoparalysis and significantly correlated with patient’s IL7R-/ICOS-expression and SOFA-scores. In whole blood, composed of innate and adaptive immune cells, both traits of immunosuppression and hyperinflammation were detected. Importantly, miR-143 and miR-150 – both predominantly expressed in T-cells – retained strong power of discrimination also in whole blood samples.

Conclusions

These findings suggest miR-143 and miR-150 as promising markers for detection of T-cell immunosuppression in whole blood and may help to develop new approaches for miRNA-based diagnostic in sepsis.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0056-z) contains supplementary material, which is available to authorized users.

Non-coding RNA: a potential biomarker and therapeutic target for sepsis

Sepsis, a syndrome of physiologic, pathologic, and biochemical abnormalities caused by an altered systemic host response to infection, has become the main cause of death among patients admitted to the intensive care units. Recently, genome-wide expression analysis revealed that over 80% of the essential genetic elements were altered in critically ill patients. Notably, non-coding RNAs, including microRNAs, long non-coding RNAs and circular RNAs, have been proven to play essential roles in innate immunity, mitochondrial dysfunction and organ dysfunction. In this review, we introduced the biogenesis of non-coding RNAs briefly and summed up different kinds of non-coding RNAs in regulation of sepsis, which could provide a more comprehensive understanding about pathogenesis of the disease. Additionally, we summarized the limitations of current biomarkers and then recommended some non-coding RNAs as novel potential biomarkers for sepsis and sepsis-induced organ dysfunction. Besides, we also introduced some problems and challenges that need to be overcome during the clinical application of non-coding RNAs. Future research should focus on elucidating their molecular mechanisms, particularly long non-coding RNAs as well as circular RNAs and sepsis, to further understanding of the disease process. With the in-depth understanding of the mechanism of sepsis, non-coding RNAs provide a new insight into sepsis and could become the novel therapeutic targets in the future.

The involvement of regulatory non-coding RNAs in sepsis: a systematic review

Background

Sepsis coincides with altered gene expression in different tissues. Accumulating evidence has suggested that microRNAs, long non-coding RNAs, and circular RNAs are important molecules involved in the crosstalk with various pathways pertinent to innate immunity, mitochondrial functions, and apoptosis.

Methods

We searched articles indexed in PubMed (MEDLINE), EMBASE and Europe PubMed Central databases using the Medical Subject Heading (MeSH) or Title/Abstract words (“microRNA”, “long non-coding RNA”, “circular RNA”, “sepsis” and/or “septic shock”) from inception to Sep 2016. Studies investigating the role of host-derived microRNA, long non-coding RNA, and circular RNA in the pathogenesis of and as biomarkers or therapeutics in sepsis were included. Data were extracted in terms of the role of non-coding RNAs in pathogenesis, and their applicability for use as biomarkers or therapeutics in sepsis. Two independent researchers assessed the quality of studies using a modified guideline from the Systematic Review Center for Laboratory animal Experimentation (SYRCLE), a tool based on the Cochrane Collaboration Risk of Bias tool.

Results

Observational studies revealed dysregulation of non-coding RNAs in septic patients. Experimental studies confirmed their crosstalk with JNK/NF-κB and other cellular pathways pertinent to innate immunity, mitochondrial function, and apoptosis. Of the included studies, the SYRCLE scores ranged from 3 to 7 (average score of 4.55). This suggests a moderate risk of bias. Of the 10 articles investigating non-coding RNAs as biomarkers, none of them included a validation cohort. Selective reporting of sensitivity, specificity, and receiver operating curve was common.

Conclusions

Although non-coding RNAs appear to be good candidates as biomarkers and therapeutics for sepsis, their differential expression across tissues complicated the process. Further investigation on organ-specific delivery of these regulatory molecules may be useful.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1555-3) contains supplementary material, which is available to authorized users.

Bcl-2 and Fas expression in peripheral blood leukocytes of patients with alcoholic and autoimmune liver disorders

BACKGROUND

This article is devoted to the inquiry of three diseases of the liver: alcoholic liver disease (ALD), primary biliary cirrhosis (PBC), and autoimmune hepatitis (AIH). The aim of the study was to assess the changes in populations of circulating lymphocytes expressing antiapoptotic bcl-2 molecule and proapoptotic Fas (cluster of differentiation 95(CD95)) receptor in patients with ALD, AIH, and PBC.

MATERIALS AND METHODS

The study population consisted of 110 patients with ALD (n = 50), PBC (n = 30), and AIH (n = 30) and age-matched healthy volunteers (n = 25). Peripheral blood lymphocytes were isolated, stained with monoclonal antibodies against CD4, CD8, and CD19 antigen; intracellular bcl-2; and surface Fas receptor (CD95) antigens, and estimated using the flow cytometric method.

RESULTS

Bcl-2 expression was the highest in CD4+ and CD19+ T lymphocytes in ALD; however, only the differences in median/mean fluorescence intensity values of CD4+bcl-2+ lymphocytes between ALD and PBC group and CD19+bcl-2+ between ALD and PBC groups were statistically significant, indicating the different role of B cells in pathology of ALD and PBC. In contrast to that, statistically significant higher percentage of CD4+, CD8+, and CD19+ bearing Fas receptor in all groups of patients with liver diseases in comparison with the control subjects were estimated. The highest expression of Fas in CD4+ lymphocytes in ALD and in CD8+ cells of PBC and AIH groups were detected.

CONCLUSION

Low expression of bcl-2 molecule and high expression of Fas in peripheral blood lymphocytes indicate significant dysregulation of apoptotic mechanisms not only in the liver but also in peripheral blood lymphocytes in all examined groups, especially in ALD group.

Serum Sphingolipid Variations Associate with Hepatic Decompensation and Survival in Patients with Cirrhosis

Background

Sphingolipids constitute bioactive molecules with functional implications in liver homeostasis. Particularly, ablation of very long chain ceramides in a knockout mouse model has been shown to cause a severe hepatopathy.

Methods

We aimed to evaluate the serum sphingolipid profile of 244 patients with cirrhosis prospectively followed for a median period of 228±217 days via mass spectrometry.

Results

We thereby observed a significant decrease of long and very long chain ceramides, particularly of C24ceramide, in patients with increasing severity of cirrhosis (p<0.001). Additionally, hydropic decompensation, defined by clinical presentation of ascites formation, was significantly correlated to low C24ceramide levels (p<0.001) while a significant association to hepatic decompensation and poor overall survival was observed for low serum concentrations of C24ceramide (p<0.001) as well. Multivariate analysis further identified low serum C24ceramide to be independently associated to overall survival (standard beta = -0.001, p = 0.022).

Conclusions

In our current analysis serum levels of very long chain ceramides show a significant reciprocal correlation to disease severity and hepatic decompensation and are independently associated with overall survival in patients with cirrhosis. Serum sphingolipid metabolites and particularly C24ceramide may constitute novel molecular targets of disease severity, hepatic decompensation and overall prognosis in cirrhosis and should be further evaluated in basic research studies.

The role of the globular heads of the C1q receptor in HPV-16 E2-induced human cervical squamous carcinoma cell apoptosis via a mitochondria-dependent pathway

Background

Human papillomavirus type-16 (HPV-16) E2 protein acts as a transcriptional modulator and plays a key role in regulating many biological responses. The purpose of this study was to investigate the relationship between HPV-16 E2, the receptor for the globular heads of human C1q (gC1qR) gene expression, mitochondrial dysfunction and apoptosis regulation in human cervical squamous carcinoma cells (C33a and SiHa).

Methods

HPV-16 E2 and gC1qR expression was examined using real-time PCR and western blot analysis. Apoptosis in C33a and SiHa cells was assessed by flow cytometry. Mitochondrial function was detected via ROS generation, the amount of cytosolic Ca²⁺, and changes in the mitochondrial membrane potential (Δψm).

Results

The expression of the HPV-16 E2 and gC1qR gene significantly decreased in human cervical squamous carcinoma samples relative to the non-cancerous cervix samples. C33a and SiHa cells that were transfected with a vector encoding HPV-16 E2 displayed significantly increased gC1qR gene expression and mitochondrial dysfunction as well as an up-regulation of cellular apoptosis, which was abrogated by the addition of gC1qR small-interfering RNA (siRNA).

Conclusions

These data support a mechanism whereby gC1qR plays an important role in HPV-16 E2-induced human cervical squamous carcinoma cell apoptosis via a mitochondria-dependent pathway.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-014-0286-y) contains supplementary material, which is available to authorized users.

Profiling circulating microRNA expression in experimental sepsis using cecal ligation and puncture

The levels of circulating microRNAs (miRNAs) in mice with experimental sepsis induced by cecal ligation and puncture (CLP) were determined using whole blood samples obtained from C57BL/6 mice at 4, 8, and 24 h after CLP; miRNA expression analysis was performed in these samples using an miRNA array. Microarray analysis revealed upregulation of 10 miRNA targets (miR-16, miR-17, miR-20a, miR-20b, miR-26a, miR-26b, miR-106a, miR-106b, miR-195, and miR-451). The expression of these miRNA targets in the whole blood, serum, and white blood cells (WBCs) of CLP mice was quantified using quantitative real-time PCR; these values were compared to those in sham-operated C57BL/6 mice, and the results indicated that these miRNA targets were significantly up-regulated in the whole blood and serum but not in the WBCs. In addition, the levels of these 10 miRNA targets in the serum of Tlr2-/-, Tlr4-/-, and NF-κB-/- mice at 8 h after CLP did not decrease significantly., which indicated that the transcription of these miRNAs was not directly mediated by the TLR2/NF-κB or TLR4/NF-κB pathway, and pathways induced by exposure to the gram-positive or gram-negative bacteria. Immunoprecipitation with the Argonaute 2 ribonucleoprotein complex revealed significantly increased expression of the 10 miRNA targets in the serum of mice after CLP, and the levels of 6 (miR-16, miR-17, miR-20a, miR-20b, miR-26a, and miR-26b) of these 10 miRNA targets increased significantly in exosomes isolated using ExoQuick precipitation solution. In this study, we identified circulating miRNAs that were up-regulated after CLP and determined the increase in the levels of these miRNAs, and our results suggest that circulating Ago2 complexes and exosomes may be responsible for the stability of miRNAs in the serum.