Dysregulation in microRNA expression in peripheral blood mononuclear cells of sepsis patients is associated with immunopathology

Proinflammatory Bone Marrow Mesenchymal Stem Cell-Derived Exosomal miR-150-3p Suppresses Proinflammatory Polarization of Alveolar Macrophages in Sepsis by Targeting Inhibin Subunit Beta A

Bone marrow mesenchymal stem cell (BMSC)-derived exosomes can protect lung tissues against sepsis, but its related mechanism remains elusive. BMSCs were primed with or without lipopolysaccharide (LPS) before extracting exosomes. The isolated exosomes were identified by transmission electron microscopy, nanoparticle tracking analysis, and western blot. LPS-stimulated macrophages were cocultured with exosomes for 24 h, followed by enzyme-linked immunosorbent assay, flow cytometry, and molecular experiments. Bioinformatics and luciferase assay were employed to investigate the interaction between miR-150-3p and inhibin subunit beta A (INHBA). MiR-150-3p expression was increased in exosomes in a proinflammatory environment. Exosomes suppressed proinflammatory polarization by downregulating IL-6, IL-1β, iNOS, and CD86, as well as promoted anti-inflammatory polarization by upregulating IL-10, ARG-1, and CD206 in LPS-stimulated macrophages. Such effects were more pronounced by LPS-primed exosomes, which was reversed in the absence of miR-150-3p. MiR-150-3p targeted INHBA. INHBA silencing decreased CD86 expression and increased CD206 expression in macrophages, but these effects were reversed by exosomal miR-150-3p inhibition. Proinflammatory BMSC-derived exosomal miR-150-3p suppressed proinflammatory polarization and promoted anti-inflammatory polarization of alveolar macrophages to attenuate LPS-induced sepsis by targeting INHBA.

Searching for airways biomarkers useful to identify progressive pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive disorder with unknown etiology. To date, the identification of new diagnostic, prognostic and progression biomarkers of IPF turns out to be necessary. MicroRNA (miRNA) are small non-coding RNAs which negatively regulate gene expression at the post-transcriptional level in several biological and pathological processes. An aberrant regulation of gene expression by miRNA is often associated with various diseases, including IPF. As result, miRNAs have emerged as potential biomarkers with relevance to pulmonary fibrosis. Several reports suggested that miRNAs are secreted as microvesicles or exosome, and hance they are stable and can be readily detected in the circulation. In the contest of miRNAs as circulating biomarkers, different studies show their role in various types of interstitial lung diseases and suggest that these small molecules could be used as prognostic markers of the disease. Exosomes are small, lipid-bound vesicles able to carry various elements of the naïve cells such as proteins, lipids, mRNAs and miRNA to facilitate cell communication under normal and diseases condition. Exosomal miRNAs (exo-miRNA) have been studied in relation to many diseases. However, there is little or no knowledge regarding exo-miRNA in bronchoalveolar lavage (BAL) in IPF. Our study's aim is to evaluate the changes in the expression of two exo-miRNAs in BAL, respectively miR-21 and miR-92a, through highlighting the differences between IPF, progressive pulmonary fibrosis (PPF) and not-progressive pulmonary fibrosis (nPPF).

METHODS

Exosomes were characterized by Western Blot and Multiplex Surface Marker Analysis. Exosomal miRNA expression was performed by qRT-PCR. ANOVA or Kruskal-Wallis test, based on data normality, was used to compare the differential expression between groups.

RESULTS

MiR-21 expression was significantly higher in the nPPF group than in both IPF and PPF. A result that could point above a possible role of miR-21, as a biomarker in the differential diagnosis between PPF and nPPF. MiR-92a, indeed, was down regulated in PPF compared to IPF and down regulated in PPF compared to nPPF.

CONCLUSIONS

This study demonstrated the putative role of both miR-21 and miR-92a as possible biomarkers of pulmonary fibrosis progression. Moreover, the role of exo-miRNAs is examined as a possible future direction that could lead to new therapeutic strategies for the treatment of progressive and non-progressive pulmonary fibrosis.

[Association of gene polymorphisms of MyD88 and TICAM1 and their interactions with community-acquired pneumonia in children]

OBJECTIVES

To investigate the association of single nucleotide polymorphisms (SNPs) of myeloid differentiation factor 88 (MyD88) and Toll-like receptor adaptor molecule 1 (TICAM1) and their interactions with community-acquired pneumonia (CAP) in children.

METHODS

Improved multiple ligase detection reaction assay was used for detecting the polymorphisms of nine tagging SNPs of the MyD88 and TICAM1 genes in 375 children with CAP who attended the Department of Pediatrics of the Second Affiliated Hospital of Yan'an University Medical School from August 2015 to September 2017 and 306 healthy children who underwent physical examination. A logistic regression analysis was used to evaluate the association between the distribution of genotypes and their interactions with CAP in children.

RESULTS

The polymorphism of the TICAM1 gene at rs11466711T/C locus was closely associated with the susceptibility to CAP in children (P<0.05). The AA genotype of rs35747610G/A locus significantly reduced risk of sepsis in children with CAP (P<0.05). The AA genotype of rs6510826G/A locus was significantly associated with the increase in C-reactive protein level in children with CAP (P<0.05). The GG genotype of the MyD88 gene at rs7744A/G locus significantly increased the risk of respiratory failure and circulatory failure (P<0.05). The multiplicative interactions between MyD88 gene rs7744A/G and TICAM1 gene rs11466711T/C, rs2292151G/A, rs35299700C/T, and rs35747610G/A loci were significantly associated with the susceptibility to CAP, the severity of CAP, and the risk of sepsis in children (P<0.05).

CONCLUSIONS

The gene polymorphisms of MyD88 and TICAM1 and their interactions are closely associated with CAP in children, with a synergistic effect on the development and progression of CAP in children.

The Role of ncRNAs in Cardiac Infarction and Regeneration

Myocardial infarction is the most prevalent cardiovascular disease worldwide, and it is defined as cardiomyocyte cell death due to a lack of oxygen supply. Such a temporary absence of oxygen supply, or ischemia, leads to extensive cardiomyocyte cell death in the affected myocardium. Notably, reactive oxygen species are generated during the reperfusion process, driving a novel wave of cell death. Consequently, the inflammatory process starts, followed by fibrotic scar formation. Limiting inflammation and resolving the fibrotic scar are essential biological processes with respect to providing a favorable environment for cardiac regeneration that is only achieved in a limited number of species. Distinct inductive signals and transcriptional regulatory factors are key components that modulate cardiac injury and regeneration. Over the last decade, the impact of non-coding RNAs has begun to be addressed in many cellular and pathological processes including myocardial infarction and regeneration. Herein, we provide a state-of-the-art review of the current functional role of diverse non-coding RNAs, particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in different biological processes involved in cardiac injury as well as in distinct experimental models of cardiac regeneration.

MicroRNA-143-3p ameliorates collagen-induced arthritis by polarizing naive CD4+ T cells into Treg cells

BACKGROUND

Rheumatoid arthritis (RA) is a persistent and systemic autoimmunity disease. The abnormal differentiation of Treg cells is important in pathogenesis. Despite previous studies showed that microRNAs (miRNAs, miR) are pivotal modulators of Treg cells, the effect of miRNAs on Treg cell differentiation and function is not clear. Our study wants to reveal the relationship of miR-143-3p with the differentiative ability and biofunction of Treg cells during the development of RA.

METHODS

The Expressing level of miR-143-3p and cell factor generation in peripheral blood (PB) of RA sufferers were identified by ELISA or RT-qPCR. The roles of miR-143-3p in Treg cell differentiation were studied via ShRNA/lentivirus transfection. Male DBA/1 J mice were separated into control, model, control mimics, and miR-143-3p mimics groups to analyze the anti-arthritis efficacy, the differentiative ability of Treg cells, and the expression level of miR-143-3p.

RESULTS

Our team discovered that the Expressing level of miR-143-3p was related to RA disease activities in a negative manner, and remarkably related to antiinflammation cell factor IL-10. In vitro, the expression of miR-143-3p in the CD4⁺ T cells upregulated the percentage of CD4⁺ CD25⁺ Fxop3⁺ cells (Tregs) and forkhead box protein 3 (Foxp3) mRNA expression. Evidently, miR-143-3p mimic intervention considerably upregulated the content of Treg cells in vivo, validly avoided CIA progression, and remarkably suppressed the inflammatory events of joints in mice.

CONCLUSION

Our findings indicated that miR-143-3p could ameliorate CIA through polarizing naive CD4⁺ T cells into Treg cells, which may be a novel strategy to treat autoimmune diseases such as RA.

Role of miRNA dysregulation in sepsis

Background

Sepsis is defined as a state of multisystem organ dysfunction secondary to a dysregulated host response to infection and causes millions of deaths worldwide annually. Novel ways to counteract this disease are needed and such tools may be heralded by a detailed understanding of its molecular pathogenesis. MiRNAs are small RNA molecules that target mRNAs to inhibit or degrade their translation and have important roles in several disease processes including sepsis.

Main body

The current review adopted a strategic approach to analyzing the widespread literature on the topic of miRNAs and sepsis. A pubmed search of “miRNA or microRNA or small RNA and sepsis not review” up to and including January 2021 led to 1140 manuscripts which were reviewed. Two hundred and thirty-three relevant papers were scrutinized for their content and important themes on the topic were identified and subsequently discussed, including an in-depth look at deregulated miRNAs in sepsis in peripheral blood, myeloid derived suppressor cells and extracellular vesicles.

Conclusion

Our analysis yielded important observations. Certain miRNAs, namely miR-150 and miR-146a, have consistent directional changes in peripheral blood of septic patients across numerous studies with strong data supporting a role in sepsis pathogenesis. Furthermore, a large body of literature show miRNA signatures of clinical relevance, and lastly, many miRNAs deregulated in sepsis are associated with the process of endothelial dysfunction. This review offers a widespread, up-to-date and detailed discussion of the role of miRNAs in sepsis and is meant to stimulate further work in the field due to the potential of these small miRNAs in prompt diagnostics, prognostication and therapeutic agency.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00527-z.

Chromatin-Associated Molecular Patterns (CAMPs) in sepsis

Several molecular patterns have been identified that recognize pattern recognition receptors. Pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) are commonly used terminologies to classify molecules originating from pathogen and endogenous molecules, respectively, to heighten the immune response in sepsis. Herein, we focus on a subgroup of endogenous molecules that may be detected as foreign and similarly trigger immune signaling pathways. These chromatin-associated molecules, i.e., chromatin containing nuclear DNA and histones, extracellular RNA, mitochondrial DNA, telomeric repeat-containing RNA, DNA- or RNA-binding proteins, and extracellular traps, may be newly classified as chromatin-associated molecular patterns (CAMPs). Herein, we review the release of CAMPs from cells, their mechanism of action and downstream immune signaling pathways, and targeted therapeutic approaches to mitigate inflammation and tissue injury in inflammation and sepsis.

Characterization of Altered Gene Expression and Histone Methylation in Peripheral Blood Mononuclear Cells Regulating Inflammation in COVID-19 Patients

The pandemic of COVID-19 has caused >5 million deaths in the world. One of the leading causes of the severe form of COVID-19 is the production of massive amounts of proinflammatory cytokines. Epigenetic mechanisms, such as histone/DNA methylation, miRNA, and long noncoding RNA, are known to play important roles in the regulation of inflammation. In this study, we investigated if hospitalized COVID-19 patients exhibit alterations in epigenetic pathways in their PBMCs. We also compared gene expression profiles between healthy controls and COVID-19 patients. Despite individual variations, the expressions of many inflammation-related genes, such as arginase 1 and IL-1 receptor 2, were significantly upregulated in COVID-19 patients. We also found the expressions of coagulation-related genes Von Willebrand factor and protein S were altered in COVID-19 patients. The expression patterns of some genes, such as IL-1 receptor 2, correlated with their histone methylation marks. Pathway analysis indicated that most of those dysregulated genes were in the TGF-β, IL-1b, IL-6, and IL-17 pathways. A targeting pathway revealed that the majority of those altered genes were targets of dexamethasone, which is an approved drug for COVID-19 treatment. We also found that the expression of bone marrow kinase on chromosome X, a member of TEC family kinases, was increased in the PBMCs of COVID-19 patients. Interestingly, some inhibitors of TEC family kinases have been used to treat COVID-19. Overall, this study provides important information toward identifying potential biomarkers and therapeutic targets for COVID-19 disease.

MicroRNA Expression in Neonates with Late-onset Sepsis - A Cross-sectional Comparative Study

BACKGROUND

Neonatal sepsis is a major health concern among neonates with higher morbidity and mortality rate. Studies have recently speculated the importance of differential expression of circulating mature micro-RNAs (miRNAs) which could serve as diagnostic as well as prognostic markers for risk of mortality in neonatal sepsis. This study aimed to analyze the expression pattern and to assess the diagnostic/prognostic value of miRNAs miR-21, miR-29a miR-31, miR-146a, and miR-155 in late-onset neonatal sepsis.

METHODS

A cross-sectional comparative study was conducted including 42 healthy controls and 42 neonates with late-onset neonatal sepsis. SYBR green-based miScript RT-PCR assay was used for the expression analysis and the comparative Ct method 2-delta (Ct) method was used for relative quantification of the candidate miRNAs in plasma. Significantly higher expression of miR-21 and miR-155 and lower expression of miR-29a and miR-146a was observed in cases compared to control except miR-31. In subgroups analysis, miR-21(p = .03) showed a significant difference between pre-term and term neonates and miR-31 (p = .01) and miR-155 (p = .03) showed a significant difference between low-birth-weight and normal-birth-weight neonates. miR-146a showed significantly lower expression in the non-survivor group compared to the survivor group (p = .005). A receiver operating characteristic curve (ROC) analysis of miR-21 and miR-29a (0.829 and 0.787 AUC of ROC curves) showed good discrimination for the identification of sepsis from non-sepsis neonates.

CONCLUSION

The current study shows evidence of differential expression of miRNAs in neonatal sepsis and this altered expression of candidate miRNAs could be involved in immune dysregulation, thus leading to sepsis-related severity in newborns.

microRNA-193-3p attenuates myocardial injury of mice with sepsis via STAT3/HMGB1 axis

Objective

Little is known regarding the functional role of microRNA-193-3p (miR-193-3p) in sepsis. Hence, the aim of the present study was to investigate the effect of miR-193-3p on myocardial injury in mice with sepsis and its mechanism through the regulation of signal transducers and activators of transcription 3 (STAT3).

Methods

The mice model of sepsis was established by cecal ligation and puncture (CLP), septic mice were injected with miR-193-3p agomir, miR-193-3p antagomir or siRNA-STAT3. The expression of miR-193-3p, STAT3 and HMGB1 in the myocardial tissue of septic mice were detected. Cardiac ultrasound, hemodynamics, myocardial injury markers, inflammatory factors and cardiomyocyte apoptosis in septic mice were measured.

Results

MiR-193-3p expression was reduced while STAT3 expression was increased in septic mice. Down-regulated STAT3 or up-regulated miR-193-3p improved cardiac function, attenuated myocardial injury, inflammation and cardiomyocyte apoptosis in septic mice. Knockdown STAT3 reversed the role of inhibited miR-193-3p for mice with sepsis. miR-193-3p targeted STAT3, thereby inhibiting HMGB1 expression.

Conclusion

This study provides evidence that miR-193-3p targets STAT3 expression to reduce HMGB1 expression, thereby reducing septic myocardial damage. MiR-193-3p might be a potential candidate marker and therapeutic target for sepsis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03022-x.

LncRNA DANCR improves the dysfunction of the intestinal barrier and alleviates epithelial injury by targeting the miR-1306-5p/PLK1 axis in sepsis

Intestinal barrier dysfunction often occurs in various acute or chronic pathological conditions and has been identified as an important clinical problem. Herein, we explored the biological role and molecular mechanism of Polo-like kinase 1 (PLK1) and differentiation antagonizing non-protein coding RNA (DANCR) in intestinal barrier dysfunction caused by sepsis. RT-qPCR analysis was used to examine PLK1, miR-1306-5p, and DANCR expression in NCM460 cells after LPS treatment. TUNEL assay and Western blot analysis were performed to explore PLK1 function in cell apoptosis and intestinal barrier in vitro. Hematoxylin and eosin staining, Western blot analysis, and TUNEL assay were used to investigate DANCR function in the intestinal barrier and cell apoptosis in vivo. The interaction between miR-1306-5p and PLK1 (or DANCR) was validated by luciferase reporter assay. As a result, PLK1 overexpression decreased cell apoptosis and promoted intestinal barrier function. Moreover, DANCR was validated as a sponge of miR-1306-5p to target PLK1. In addition, we found that DANCR overexpression decreased intestinal mucosal permeability and colon mucosa epithelial cell apoptosis in vivo. Conclusively, DANCR improved intestinal barrier dysfunction and alleviated epithelial injury by targeting the miR-1306-5p/PLK1 axis in sepsis.

The lncRNA XIST/miR-150-5p/c-Fos axis regulates sepsis-induced myocardial injury via TXNIP-modulated pyroptosis

Myocardial injury is a severe complication of sepsis and contributes substantially to the death of critically ill patients. Long non-coding RNAs (lncRNAs) participate in the pathogenesis of sepsis-induced myocardial injury. In this study, we investigated the role of lncRNA X-inactive specific transcript (XIST) in septic myocardial injury and explored its mechanism. Lipopolysaccharide (LPS)-stimulated H9C2 cells and rats subjected to cecal ligation and puncture (CLP) were used as the in vitro and in vivo models. After exposure to LPS, XIST and c-Fos levels were upregulated, but miR-150-5p was downregulated in H9C2 cardiomyocytes and myocardial tissues. XIST affected viability, apoptosis, and pyroptosis in LPS-challenged H9C2 cells. Moreover, XIST knockdown attenuated LPS-induced injury in H9C2 cells by targeting the miR-150-5p/c-Fos axis. c-Fos could bound to the promoter of the TXNIP/XIST gene and enhanced TXNIP/XIST expression. Silencing of XIST improved cardiac function and survival rate and reduced apoptosis and pyroptosis by regulating the miR-150-5p/c-Fos axis in septic rats in vivo. Taken together, our data show that XIST/miR-150-5p/c-Fos axis affected septic myocardial injury, which may indicate a novel therapeutic strategy for sepsis-induced myocardial injury.

The Role of microRNAs and Long Non-Coding RNAs in the Regulation of the Immune Response to Mycobacterium tuberculosis Infection

Non-coding RNAs have emerged as critical regulators of the immune response to infection. MicroRNAs (miRNAs) are small non-coding RNAs which regulate host defense mechanisms against viruses, bacteria and fungi. They are involved in the delicate interplay between Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), and its host, which dictates the course of infection. Differential expression of miRNAs upon infection with M. tuberculosis, regulates host signaling pathways linked to inflammation, autophagy, apoptosis and polarization of macrophages. Experimental evidence suggests that virulent M. tuberculosis often utilize host miRNAs to promote pathogenicity by restricting host-mediated antibacterial signaling pathways. At the same time, host- induced miRNAs augment antibacterial processes such as autophagy, to limit bacterial proliferation. Targeting miRNAs is an emerging option for host-directed therapies. Recent studies have explored the role of long non-coding RNA (lncRNAs) in the regulation of the host response to mycobacterial infection. Among other functions, lncRNAs interact with chromatin remodelers to regulate gene expression and also function as miRNA sponges. In this review we attempt to summarize recent literature on how miRNAs and lncRNAs are differentially expressed during the course of M. tuberculosis infection, and how they influence the outcome of infection. We also discuss the potential use of non-coding RNAs as biomarkers of active and latent tuberculosis. Comprehensive understanding of the role of these non-coding RNAs is the first step towards developing RNA-based therapeutics and diagnostic tools for the treatment of TB.

Exosomes Derived From Heat Stroke Cases Carry miRNAs Associated With Inflammation and Coagulation Cascade

The pathological mechanism underlying heat stroke (HS) is associated with the dysbalanced inflammation and coagulation cascade. Cell-derived circulating extracellular vesicles (EVs), as a novel pathway mediating intercellular communication, are associated with the immune response and inflammation in critical inflammatory syndromes, such as sepsis. Although these vesicles contain genetic material correlated with their biological function, their molecular cargo during HS remains unknown. In this study, we evaluate the presence of microRNAs (miRNAs) and messenger RNAs (mRNAs) associated with inflammatory responses and coagulation cascade in exosomes of patients with HS. Blood samples were collected from three patients with HS at the time of admission to the intensive care unit; three healthy volunteers were selected as control. Exosomes were isolated using ultracentrifugation, and their miRNA content was profiled using next-generation sequencing; mRNA content was evaluated using qPCR array. Compared with those from healthy volunteers, exosomes from patients with HS showed substantial changes in the expression of 202 exosomal miRNAs (154 upregulated and 48 downregulated miRNAs). The most upregulated miRNAs included miR-511-3p, miR-122-5p, miR-155-3p, miR-1290, and let7-5p, whereas the most downregulated ones included miR-150-3p, 146a-5p, and 151a-3p. Gene ontology enrichment of the miRNAs of patients with HS compared with control subjects were associated mostly with inflammatory response, including T cell activation, B cell receptor signaling, dendritic cell chemotaxis and leukocyte migration, and platelet activation and blood coagulation. The identified miRNAs were primarily enriched to the signal transduction pathways namely, T cell receptor signaling, Ras signaling, chemokine signaling, platelet activation, and leukocyte transendothelial migration, all of which are associated with inflammation and hemostasis. Multiple targeted mRNAs associated with the inflammatory response, blood coagulation, and platelet activation were further verified in serum exosomes. Exosomes from patients with HS convey miRNAs and mRNAs associated with pathogenic pathways, including inflammatory response and coagulation cascade. Exosomes may represent a novel mechanism for intercellular communication during HS.

Leukocyte glucocorticoid receptor expression and related transcriptomic gene signatures during early sepsis

PURPOSE

The study aimed to understand the molecular mechanisms that might lead to differences in the glucocorticoid response during sepsis.

METHODS

Patients diagnosed with sepsis (n = 198) and 40 healthy controls were enrolled. Glucocorticoid receptor (GR) expression in circulating leukocytes and plasma levels of adrenocorticotropic hormone and cortisol on days 1 and 7 were measured in all participants. Expression profiling of 16 genes associated with GR expression in peripheral blood mononuclear cells (PBMCs) in 12 healthy controls and 26 patients with sepsis was performed by PCR.

RESULTS

Cortisol levels were higher in patients with sepsis than in healthy controls on day 1 after admission and recovered to normal levels by day 7. GR expression was gradually downregulated in leukocyte subsets. Non-survivors showed lower GR and higher cortisol levels than survivors. GRα expression was lower in patients with sepsis than in controls, whereas GRβ showed the opposite trend. MicroRNAs related to GR resistance and suppression were altered in PBMCs during sepsis.

CONCLUSION

Patients with sepsis showed upregulated plasma cortisol levels along with downregulated GR expression on various leukocyte subtypes, portending poor cortisol response and outcome. Changes in GR-regulatory miRNAs may be responsible for GR low expression.

miR-146a in Cardiovascular Diseases and Sepsis: An Additional Burden in the Inflammatory Balance?

The new concept of thrombosis associated with an inflammatory process is called thromboinflammation. Indeed, both thrombosis and inflammation interplay one with the other in a feed forward manner amplifying the whole process. This pathological reaction in response to a wide variety of sterile or non-sterile stimuli eventually causes acute organ damage. In this context, neutrophils, mainly involved in eliminating pathogens as an early barrier to infection, form neutrophil extracellular traps (NETs) that are antimicrobial structures responsible of deleterious side effects such as thrombotic complications. Although NETosis mechanisms are being unraveled, there are still many regulatory elements that have to be discovered. Micro-ribonucleic acids (miRNAs) are important modulators of gene expression implicated in human pathophysiology almost two decades ago. Among the different miRNAs implicated in inflammation, miR-146a is of special interest because: (1) it regulates among others, Toll-like receptors/nuclear factor-κB axis which is of paramount importance in inflammatory processes, (2) it regulates the formation of NETs by modifying their aging phenotype, and (3) it has expression levels that may decrease among individuals up to 50%, controlled in part by the presence of several polymorphisms. In this article, we will review the main characteristics of miR-146a biology. In addition, we will detail how miR-146a is implicated in the development of two paradigmatic diseases in which thrombosis and inflammation interact, cardiovascular diseases and sepsis, and their association with the presence of miR-146a polymorphisms and the use of miR-146a as a marker of cardiovascular diseases and sepsis.

MicroRNA-150 affects endoplasmic reticulum stress via MALAT1-miR-150 axis-mediated NF-κB pathway in LPS-challenged HUVECs and septic mice

AIMS

Sepsis is a systemic inflammatory complication, which is the common cause of death in critical patients. This study aimed to evaluate the potential regulatory mechanisms of miR-150 in lipopolysaccharide (LPS)-challenged HUVECs and cecal ligation and puncture (CLP)-induced septic mice.

MATERIALS AND METHODS

Human umbilical vein endothelial cells (HUVECs) were challenged with LPS. Pulmonary arterial endothelial cells (PAECs) were isolated from CLP-induced septic mice. The mRNA and protein levels of target molecules were detected by RT-qPCR and Western blotting. Apoptosis of HUVECs was determined by Annexin V/PI staining on a flow cytometry. The interaction between miR-150 and MALAT1 was assessed by luciferase reporter assay, RIP and RNA pull-down assay.

KEY FINDINGS

MiR-150 was downregulated in LPS-induced HUVECs. MiR-150 mimics restrained LPS-induced inflammatory response by reducing TNF-α and IL-6 levels, but increasing IL-10 level. Moreover, miR-150 mimics downregulated endoplasmic reticulum (ER) stress-related proteins, GRP78 and CHOP levels in LPS-exposed HUVECs. Additionally, LPS-induced apoptosis was suppressed by miR-150 mimics via decreasing cleaved caspase-3 and Bax levels, while enhancing Bcl-2 level. Mechanistically, MALAT1 could competitively bind to miR-150. LPS-induced apoptosis, ER stress and inflammation were promoted by MALAT1 overexpression, but reversed by siMALAT1. Furthermore, miR-150 inhibitor strengthened LPS-induced apoptosis, ER stress and inflammation, which could be attenuated by siMALAT1 via regulating NF-κB pathway. Finally, agomiR-150 repressed ER stress and inflammatory response in PAECs isolated from septic mice via decreasing MALAT1 level.

SIGNIFICANCE

Our findings suggest that miR-150 affects sepsis-induced endothelial injury by regulating ER stress and inflammation via MALAT1-mediated NF-κB pathway.

The Relationship between Extracellular/intracellular microRNAs and TLRs May Be Used as a Diagnostic and Therapeutic Approach in Sepsis

One of the leading causes of death in the intensive care unit (ICU) is sepsis. Different studies have been performed on different markers to determine the cause of sepsis. microRNAs (miRNAs) are non-coding RNAs that can be released both inside and outside the cell and regulate the target gene expression by binding to the 3' untranslated region (3'UTR) of the target genes. TLRs play an important role in innate immunity that can be modulated by biological markers such as microRNAs. In this study, we summarized the recent progress on the role of extracellular and intracellular microRNAs in sepsis. It has also been focused on the association of TLRs with extracellular and intracellular micro RNAs in the regulation of sepsis. In conclusion, this study has provided new insight into the role of microRNAs as a regulator of the TLRs which may lead to the aberrant inflammatory response in sepsis. Therefore, it suggests that both intracellular and extracellular microRNAs may play a therapeutic role in the treatment of sepsis via regulating TLRs. However, yet sepsis and septic shock are medical emergencies and further studies are needed to specify the exact role of microRNAs and TLRs in sepsis.

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.

miR-145a Regulation of Pericyte Dysfunction in a Murine Model of Sepsis

BACKGROUND

Sepsis is a life-threatening systemic disease with severe microvascular dysfunction. Pericytes preserve vascular homeostasis. To our knowledge, the potential roles of microRNAs in sepsis-induced pericyte dysfunction have not been explored.

METHODS

We determined lung pericyte expression of miR-145a in cecal ligation and puncture (CLP)-induced sepsis. Mouse lung pericytes were isolated and transfected with a miR-145a mimic, followed by stimulation with lipopolysaccharide (LPS). We measured inflammatory cytokine levels. To assess the functions of miR-145a in vivo, we generated a pericyte-specific miR-145a-knockout mouse and determined sepsis-induced organ injury, lung and renal vascular leakage, and mouse survival rates. We used RNA sequencing and Western blotting to analyze the signaling pathways regulated by miR-145a.

RESULTS

CLP led to decreased miR-145a expression in lung pericytes. The miR-145a mimic inhibited LPS-induced increases in cytokines. In CLP-induced sepsis, pericytes lacking miR-145a exhibited increased lung and kidney vascular leakage and reduced survival rates. We found that miR-145a could suppress LPS-induced NF-κB activation. In addition, we confirmed that the transcription factor Friend leukemia virus integration 1 (Fli-1) is a target of miR-145a and that Fli-1 activates NF-κB signaling.

CONCLUSION

Our results demonstrated that pericyte miR-145a mediates sepsis-associated microvascular dysfunction, potentially by means of Fli-1-mediated modulation of NF-κB signaling.

Dihydroquercetin attenuates lipopolysaccharide-induced acute lung injury through modulating FOXO3-mediated NF-κB signaling via miR-132-3p

BACKGROUND

Dihydroquercetin (DHQ) is a potent flavonoid which has been demonstrated to have multiple biological activities including anti-inflammation activity, antioxidant activity as well as anti-cancer activity etc. Recently, many studies have focused on the antioxidant activity of DHQ. However, the use of the anti-inflammation activity of DHQ in acute lung injury (ALI) has not been reported.

METHODS

Cell viability was examined by CCK-8 assay. The relative expression of miR-132-3p, FOXO3 were detected by qPCR. The levels of TNF-α, IL-6 and IL-1β were detected using enzyme-linked immunosorbent assay. The amount of apoptosis cells was detected by flow cytometry. The protein levels of Bcl-2, Bax, p-p65 and p-IκBα were measured by western blot.

RESULTS

We found that DHQ-induced the expression of miR-132-3p in LPS-induced ALI. Overexpression of miR-132-3p resulted in the inhibition of FOXO3 expression and then suppressed FOXO3-activated NF-κB pathway, attenuating LPS-induced inflammatory response and apoptosis.

CONCLUSION

We demonstrated FOXO3 to be a target of miR-132-3p, and DHQ could induce the expression of miR-132-3p, relieving LPS-induced ALI via miR-132-3p/FOXO3/NF-κB axis, providing a promising therapeutic target for ALI.

Circular RNAs in Sepsis: Biogenesis, Function, and Clinical Significance

Sepsis is a life-threatening condition that occurs when the body responds to an infection that damages it is own tissues. The major problem in sepsis is rapid, vital status deterioration in patients, which can progress to septic shock with multiple organ failure if not properly treated. As there are no specific treatments, early diagnosis is mandatory to reduce high mortality. Despite more than 170 different biomarkers being postulated, early sepsis diagnosis and prognosis remain a challenge for clinicians. Recent findings propose that circular RNAs (circRNAs) may play a prominent role in regulating the patients’ immune system against different pathogens, including bacteria and viruses. Mounting evidence also suggests that the misregulation of circRNAs is an early event in a wide range of diseases, including sepsis. Despite circRNA levels being altered in sepsis, the specific mechanisms controlling the dysregulation of these noncoding RNAs are not completely elucidated, although many factors are known to affect circRNA biogenesis. Therefore, there is a need to explore the molecular pathways that lead to this disorder. This review describes the role of this new class of regulatory RNAs in sepsis and the feasibility of using circRNAs as diagnostic biomarkers for sepsis, opening up new avenues for circRNA-based medicine.

MicroRNA: Potential biomarker and target of therapy in acute lung injury

MicroRNAs (miRNAs) are small noncoding RNAs stretching over 18-22 nucleotides and considered to be modifiers of many respiratory diseases. They are highly evolutionary conserved and have been implicated in several biological processes, including cell proliferation, apoptosis, differentiation, among others. Acute lung injury (ALI) is a fatal disease commonly caused by direct or indirect injury factors and has a high mortality rate in intensive care unit. Changes in expression of several types of miRNAs have been reported in patients with ALI. Some miRNAs suppress cellular injury and accelerate the recovery of ALI by targeting specific molecules and decreasing excessive immune response. For this reason, miRNAs are proposed as potential biomarkers for ALI and as therapeutic targets for this disease. This review summarizes current evidence supporting the role of miRNAs in ALI.

Down-regulation of circDMNT3B is conducive to intestinal mucosal permeability dysfunction of rats with sepsis via sponging miR-20b-5p

Sepsis is a life‐threatening syndrome with a high risk of mortality, which is caused by the dysregulated host response to infection. We examined significant roles of circDMNT3B and miR‐20b‐5p in the intestinal mucosal permeability dysfunction of rats with sepsis. SD rats were randomly divided into 6 groups (n = 10/group): sham group, sepsis group, si‐negative control group, circDNMT3B‐si1 group, circDNMT3B‐si2 group and circDNMT3B‐si1 + anti‐miR‐20b‐5p group. The level of malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, interleukin (IL)‐6 and IL‐10 levels were measured through ELISA assay kits. Cell survival rate and cell apoptosis were evaluated by Cell‐Counting Kit‐8 Assay and flow cytometry, respectively. Luciferase reporter assays were used to investigate interactions between miR‐20b‐5p circDMNT3B in HEK‐293T cells. Silencing circDNMT3B can significantly increase the level of d‐lactic acid, FD‐40, MDA, diamine oxidase, IL‐10 and IL‐6, compared with sepsis group, while the SOD activity was lower. Silencing circDNMT3B leads to oxidative damage and influence inflammatory factors level in intestinal tissue. CircDNMT3B was identified as a target gene of miR‐20b‐5p. Silencing circDNMT3B decreased cell survival and induced apoptosis in Caco2 cells treated with LPS, which was reversed by anti‐miR‐20b‐5p. MiR‐20b‐5p inhibitor remarkably down‐regulated mentioned‐above levels, in addition to up‐regulate SOD activity, which may relieve the damage of intestinal mucosal permeability caused by silencing circDNMT3B in sepsis rats. Down‐regulation of circDMNT3B was conducive to the dysfunction of intestinal mucosal permeability via sponging miR‐20b‐5p in sepsis rats, which may provide the novel strategy for sepsis treatment in the future.

Long non-coding RNA molecules in tuberculosis

Tuberculosis (TB), a chronic disease caused by Mycobacterium tuberculosis, is one of the deadliest infectious diseases in the world. Despite significant advances in detection techniques and therapeutic approaches for tuberculosis, there is still no suitable solution for early screening and reducing the number of individuals affected and their effective treatment. Various cellular events can disrupt the development of TB. The basis of these events is dysregulating of genes expression patterns related with specific molecules. Long non-coding RNAs (lncRNAs) are molecules discovered to regulate the expression of protein-coding genes and participate in gene silencing, cell cycle regulation and cellular differentiation processes. Dysregulation of lncRNAs has been found to be associated with many diseases, including cancers and infectious diseases. Thus, the recognition of lncRNAs as novel molecular biomarkers and therapeutic targets for tuberculosis is promising. In the present review, we try to summarize the current findings of lncRNA expression patterns and its role in tuberculosis infection process.

Sepsis therapies: learning from 30 years of failure of translational research to propose new leads

Sepsis has been identified by the World Health Organization (WHO) as a global health priority. There has been a tremendous effort to decipher underlying mechanisms responsible for organ failure and death, and to develop new treatments. Despite saving thousands of animals over the last three decades in multiple preclinical studies, no new effective drug has emerged that has clearly improved patient outcomes. In the present review, we analyze the reasons for this failure, focusing on the inclusion of inappropriate patients and the use of irrelevant animal models. We advocate against repeating the same mistakes and propose changes to the research paradigm. We discuss the long-term consequences of surviving sepsis and, finally, list some putative approaches-both old and new-that could help save lives and improve survivorship.

Correlation between TICAM1 gene polymorphisms and community-acquired pneumonia in children

This study aims to explore the relationship between single nucleotide polymorphisms (SNPs) of the TICAM1 gene and community-acquired pneumonia (CAP) in Chinese children. The polymorphisms of eight tag SNP (TagSNP) locus of TICAM1 were detected using the improved multiplex ligation detection reaction (iMLDR) assay in 375 children with CAP (average age, 37.8 ± 21.6 months) and 306 healthy children (average age, 38.5 ± 23.8 months). The correlation between polymorphisms of these TagSNPs and the risk, severity, sepsis, and CRP level of childhood CAP were evaluated using logistic regression analysis. The CC genotype of rs11466711T/C locus of TICAM1 is correlated with childhood CAP susceptibility, which significantly reduced the risk of childhood CAP (P < .05), The AA genotype of the rs6510826G/A locus and haplotype CCCA were associated with CRP level in childhood CAP, which significantly increased the risk of CRP increase (P < .05 and P < .01, respectively), The AA genotype of rs35747610G/A site is associated with sepsis in childhood CAP, significantly reduced risk of sepsis (P < .05). While the haplotype CCCG of this locus led to a significant reduction in the risks of childhood CAP, severe pneumonia and pneumonia sepsis (all P < .05). TICAM1 has multiple functional variants closely related to the development and progression of childhood CAP, and these variations may have a synergistic effect on the development of childhood CAP.

miR-146a in Myasthenia Gravis Thymus Bridges Innate Immunity With Autoimmunity and Is Linked to Therapeutic Effects of Corticosteroids

Toll-like receptor (TLR)-mediated innate immune responses are critically involved in the pathogenesis of myasthenia gravis (MG), an autoimmune disorder affecting neuromuscular junction mainly mediated by antiacetylcholine receptor antibodies. Considerable evidence indicate that uncontrolled TLR activation and chronic inflammation significantly contribute to hyperplastic changes and germinal center (GC) formation in the MG thymus, ultimately leading to autoantibody production and autoimmunity. miR-146a is a key modulator of innate immunity, whose dysregulation has been associated with autoimmune diseases. It acts as inhibitor of TLR pathways, mainly by targeting the nuclear factor kappa B (NF-κB) signaling transducers, interleukin 1 receptor associated kinase 1 (IRAK1) and tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6); miR-146a is also able to target c-REL, inducible T-cell costimulator (ICOS), and Fas cell surface death receptor (FAS), known to regulate B-cell function and GC response. Herein, we investigated the miR-146a contribution to the intrathymic MG pathogenesis. By real-time PCR, we found that miR-146a expression was significantly downregulated in hyperplastic MG compared to control thymuses; contrariwise, IRAK1, TRAF6, c-REL, and ICOS messenger RNA (mRNA) levels were upregulated and negatively correlated with miR-146a levels. Microdissection experiments revealed that miR-146a deficiency in hyperplastic MG thymuses was not due to GCs, but restricted to the GC-surrounding medulla, characterized by IRAK1 overexpression. We also showed higher c-REL and ICOS mRNA levels, and lower FAS mRNA levels, in GCs than in the remaining medulla, according to the contribution of these molecules in GC formation. By double immunofluorescence, an increased proportion of IRAK1-expressing dendritic cells and macrophages was found in hyperplastic MG compared to control thymuses, along with GC immunoreactivity for c-REL. Interestingly, in corticosteroid-treated MG patients intrathymic miR-146a and mRNA target levels were comparable to those of controls, suggesting that immunosuppressive therapy may restore the microRNA (miRNA) levels. Indeed, an effect of prednisone on miR-146a expression was demonstrated in vitro on peripheral blood cells. Serum miR-146a levels were lower in MG patients compared to controls, indicating dysregulation of the circulating miRNA. Our overall findings strongly suggest that defective miR-146a expression could contribute to persistent TLR activation, lack of inflammation resolution, and hyperplastic changes in MG thymuses, thus linking TLR-mediated innate immunity to B-cell-mediated autoimmunity. Furthermore, they unraveled a new mechanism of action of corticosteroids in inducing control of autoimmunity in MG via miR-146a.

Nanoparticle Delivery of Anti-inflammatory LNA Oligonucleotides Prevents Airway Inflammation in a HDM Model of Asthma

To address the problem of poor asthma control due to drug resistance, an antisense oligonucleotide complementary to mmu-miR-145a-5p (antimiR-145) was tested in a house dust mite mouse model of mild/moderate asthma. miR-145 was targeted to reduce inflammation, regulate epithelial-mesenchymal transitions, and promote differentiation of structural cells. In addition, several chemical variations of a nontargeting oligonucleotide were tested to define sequence-dependent effects of the miRNA antagonist. After intravenous administration, oligonucleotides complexed with a pegylated cationic lipid nanoparticle distributed to most cells in the lung parenchyma but were not present in smooth muscle or the mucosal epithelium of the upper airways. Treatment with antimiR-145 and a nontargeting oligonucleotide both reduced eosinophilia, reduced obstructive airway remodeling, reduced mucosal metaplasia, and reduced CD68 immunoreactivity. Poly(A) RNA-seq verified that antimiR-145 increased levels of many miR-145 target transcripts. Genes upregulated in human asthma and the mouse model of asthma were downregulated by oligonucleotide treatments. However, both oligonucleotides significantly upregulated many genes of interferon signaling pathways. These results establish effective lung delivery and efficacy of locked nucleic acid/DNA oligonucleotides administered intravenously, and suggest that some of the beneficial effects of oligonucleotide therapy of lung inflammation may be due to normalization of interferon response pathways.

Immunotherapy in sepsis - brake or accelerate?

Sepsis, a life threating syndrome characterized by organ failure after infection, is the most common cause of death in hospitalized patients. The treatment of sepsis is generally supportive in nature, involving the administration of intravenous fluids, vasoactive substances and oxygen plus antibiotics to eliminate the pathogen. No drugs have been approved specifically for the treatment of sepsis, and clinical trials of potential therapies have failed to reduce mortality - suggesting that new approaches are needed. Abnormalities in the immune response elicited by the pathogen, ranging from excessive inflammation to immunosuppression, contribute to disease pathogenesis. Although hundreds of immunomodulatory agents are potentially available, it remains unclear which patient benefits from which immune therapy at a given time point. Results indicate the importance of personalized therapy, specifically the need to identify the type of intervention required by each individual patient at a given point in the disease process. To address this issue will require using biomarkers to stratify patients based on their individual immune status. This article reviews recent and ongoing clinical investigations using immunostimulatory or immunosuppressive therapies against sepsis including non-pharmacological and novel preclinical approaches.

Diagnostic and prognostic significance of serum miRNA-146-a expression in Egyptian children with sepsis in a pediatric intensive care unit

BACKGROUND

Previous studies have suggested a strong genetic effect on sepsis pathogenesis. The present study aimed to investigate the role of miRNA-146-a expression in pediatric sepsis.

METHODS

The study included 55 pediatric sepsis patients and 60 control children of the same age and sex. Serum miRNA-146-a expression was measured using a quantitative real-time polymerase chain reaction. C-reactive protein, interleukin-6, tumor necrosis factor-α and procalcitonin levels were measured by an enzyme-linked immunosorbent assay. The outcome of the pediatric sepsis group was determined at 28 days of follow up.

RESULTS

The results obtained revealed that serum miRNA-146-a levels were significantly decreased in sepsis group compared to the control group. Serum level of miRNA-146a correlated with sepsis severity, with the pediatric septic shock group having the lowest level, followed by the severe sepsis and sepsis groups. The miRNA-146-a level could indicate sepsis (area under curve = 0.803). Serum miRNA-146-a expression was negatively associated with C-reactive protein, pro-calcitonin, interleukin-6 and tumor necrosis factor-α. Patients with miRNA-146-a at a level lower than 0.4 had an increased mortality rate.

CONCLUSIONS

miRNA-146-a is of significant diagnostic and prognostic value in pediatric sepsis and could be used for planning therapeutic strategies.

Identification of suitable controls for miRNA quantification in T-cells and whole blood cells in sepsis

Complex immune dysregulation is a hallmark of sepsis. The occurring phases of immunosuppression and hyperinflammation require rapid detection and close monitoring. Reliable tools to monitor patient’s immune status are yet missing. Currently, microRNAs are being discussed as promising new biomarkers in sepsis. However, no suitable internal control for normalization of miRNA expression by qPCR has been validated so far, thus hampering their potential benefit. We here present the first evaluation of endogenous controls for miRNA analysis in human sepsis. Novel candidate reference miRNAs were identified via miRNA microArray. TaqMan qPCR assays were performed to evaluate these microRNAs in T-cells and whole blood cells of sepsis patients and healthy controls in two independent cohorts. In T-cells, U48 and miR-320 proved suitable as endogenous controls, while in whole blood cells, U44 and miR-942 provided best stability values for normalization of miRNA quantification. Commonly used snRNA U6 exhibited worst stability in all sample groups. The identified internal controls have been prospectively validated in independent cohorts. The critical importance of housekeeping gene selection is emphasized by exemplary quantification of imuno-miR-150 in sepsis patients. Use of appropriate internal controls could facilitate research on miRNA-based biomarker-use and might even improve treatment strategies in the future.

microRNA-21 regulates astrocytic reaction post-acute phase of spinal cord injury through modulating TGF-β signaling

Astrogliosis following spinal cord injury (SCI) was considered as a negative factor for neural regeneration. We found that miR-21 was significantly upregulated after SCI. So, we aim to determine whether miR-21 acts in a positive manner post SCI. In vitro, we measured the proliferation, apoptosis and cytokine secretion of primary cultured astrocytes after modulating the expression of miR-21 by western blot, RT-PCR and immunofluorescence. In vivo, we performed a modified Allen's weight drop model. Manipulation of the miR-21 expression level was achieved by interfering with antagomir and agomir. Clinic score was evaluated and recorded every day. Then, western blot, immunohistochemistry, TUNEL assay and ELISA were performed to detect pathological and functional alterations. Our results demonstrate that miR-21 can modulate the secretion, proliferation and apoptosis of astrocytes to promote recovery after SCI both in vivo and in vitro. These effects are likely mediated through transforming growth factor beta mediated targeting of the PI3K/Akt/mTOR pathway. These data suggest that miR-21 can regulate astrocytic function, then promote the functional recovery after SCI. We therefore highlight the positive effects of miR-21 after SCI.

Immunomodulation by vasoactive intestinal peptide is associated with increased survival and growth of Salmonella Typhimurium in mice

Studies have shown that administration of vasoactive intestinal peptide (VIP) in mice rescues them from lethal endotoxaemia and that this is correlated with decreased concentration of inflammatory cytokines. VIP has, therefore, been proposed as a novel anti-inflammatory which could be used in the treatment of Gram negative sepsis. However, the effect of VIP has not been reported in mice infected with viable Gram negative bacteria. Here, we show that Salmonella enterica serovar Typhimurium 4/74 significantly increased expression of mRNA of a type 1 receptor (VPAC1) for anti-inflammatory vasoactive intestinal peptide (VIP) in murine ileum and mesenteric lymph nodes at day 6 post-infection (d6 pi) and in the spleen at d3 pi. When VIP (5 nmol/ml) was administered to S. Typhimurium-infected mice, there was a significant increase in the number of S. Typhimurium cultured from murine faeces and ileum at d3 and 6 pi and in MLN and spleen at d3 dpi, compared to faeces and tissues examined from mice infected with S. Typhimurium (without VIP administration). Administration of VIP to S. Typhimurium-infected mice also altered the splenic architecture, resulting in a lack of discernable periarterial lymphoid sheaths or marginal zones at d6 pi but liver histology appeared similar on both d3 and d6 pi. The effects of VIP administration were correlated with a significant decrease in expression of inflammatory cytokine mRNA, associated with systemic inflammatory response syndrome (SIRS) of bacteraemia and acute sepsis. We conclude that VIP inhibits expression of diagnostic/prognostic cytokine biomarkers of sepsis in S. Typhimurium-infected mice. However, this occurred with a concomitant increase in Salmonella growth in tissues and increased bacterial shedding in faeces. Thus, VIP may have potential as an adjunctive therapy to antibiotics in sepsis.

Role of sepsis modulated circulating microRNAs

Sepsis is a life-threating condition with dysregulated systemic host response to microbial pathogens leading to disproportionate inflammatory response and multi-organ failure. Various biomarkers are available for the diagnosis and prognosis of sepsis; however, these laboratory parameters may show limitations in these severe clinical conditions. MicroRNAs (miRNA) are single-stranded non-coding RNAs with the function of post-transcriptional gene silencing. They normally control numerous intracellular events, such as signaling cascade downstream of Toll-like receptors (TLRs) to avoid excessive inflammation after infection. In contrast, abnormal miRNA expression contributes to the development of sepsis correlating with its clinical features and outcomes. Based on recent clinical studies altered levels of circulating miRNAs can act as potential diagnostic and prognostic biomarkers in sepsis. In this review, we summarized the available data about TLR-mediated inflammatory signaling with its intracellular response in immune cells and platelets upon sepsis, which are, at least in part, under the regulation of miRNAs. Furthermore, the role of circulating miRNAs is also described as potential laboratory biomarkers in sepsis.

MicroRNA-140 inhibits skeletal muscle glycolysis and atrophy in endotoxin-induced sepsis in mice via the WNT signaling pathway

Sepsis is a systemic inflammatory response syndrome resulting from infection. This study aimed at exploring the role of microRNA-140 (miR-140) in septic mice. Wnt family member 11 (WNT11) was verified to be a target gene of miR-140 after bioinformatic prediction and dual luciferase reporter gene assay. Importantly, miR-140 negatively regulated WNT11. We initially induced the model of sepsis by endotoxin, and then ectopic expression and knockdown experiments were performed to explore the functional role of miR-140 in sepsis. Additionally, cross-sectional areas of muscle fiber, lactic acid production, 3-methylhistidine (3-MH) and tyrosine (Tyr) production in extensor digitorium longus (EDL) muscles, and serum levels of inflammatory factors were examined. The effect of miR-140 on the expression of WNT signaling pathway-related and apoptosis-related factors in skeletal muscle tissue was determined. The experimental results indicated that upregulated miR-140 or silenced WNT11 increased cross-sectional areas of muscle fiber while decreasing lactic acid production, skeletal muscle cell apoptosis [corresponding to downregulated B cell lymphoma 2 (Bcl-2)-associated X protein (Bax) and caspase-3 and upregulated Bcl-2], and the proteolytic rate of Tyr and 3-MH. Also, overexpressed miR-140 or silenced WNT11 reduced inflammation as reflected by decreased serum levels of IL-6, IL-10, and TNF-α. Furthermore, overexpression of miR-140 was shown to suppress the activation of the WNT signaling pathway, accompanied by decreased expression of WNT11, β-catenin, and GSK-3β. Taken together, upregulation of miR-140 could potentially inhibit skeletal muscle lactate release, an indirect measure of glycolysis, and atrophy in septic mice through suppressing the WNT signaling pathway via inhibiting WNT11 expression.

Clinical significance of lnc-AC145676.2.1-6 and lnc-TGS1-1 and their variants in western Chinese tuberculosis patients

OBJECTIVES

Tuberculosis (TB) remains a global public health problem. Recent studies have implicated long non-coding RNAs and their variants as possibly playing important roles in TB. The aim of this study was to assess the clinical relevance of lnc-AC145676.2.1-6 and lnc-TGS1-1 and their variants in a western Chinese population.

METHODS

This case-control study included 467 TB patients and 473 healthy controls from West China Hospital. The expression levels of lnc-AC145676.2.1-6 and lnc-TGS1-1 were analyzed by reverse transcriptase quantitative real-time PCR. Single-nucleotide polymorphism genotyping was performed using a custom-designed 2 × 48-Plex SNPscan kit.

RESULTS

It was observed that lnc-AC145676.2.1-6 and lnc-TGS1-1 expression levels were both obviously down-regulated in TB patients. In addition, a lower expression level of lnc-TGS1-1 was associated with the presence of thrombocytopenia in TB patients during anti-TB treatment, and the homozygous CC genotype of rs4737420 correlated with a decreased risk of leukopenia, compared with individuals with the T allele (TT/CT genotype), in the dominant mode.

CONCLUSIONS

For the first time, potential TB-associated promoting effects were identified for the decreased expression levels of lnc-AC145676.2.1-6 and lnc-TGS-1, while lnc-TGS1-1 and its variant rs4737420 may be predictive indicators of anti-TB drug-induced adverse drug reactions. Larger validation studies on different populations are warranted to confirm these findings.

Recent advances in nanomedicine for sepsis treatment

Sepsis and septic shock are life-threating conditions, which form a continuum of the body's response to overwhelming infection. The current treatment consists of fluid and metabolic resuscitation, hemodynamic and end-organ support, and timely initiation of antibiotics. However, these measures may be ineffective and the sepsis-related mortality toll remains substantial; therefore, an urgent need exists for new therapies. Recently, several nanoparticle (NP) systems have shown excellent protective effects against sepsis in preclinical models, suggesting a potential utility in the management of sepsis and septic shock. These NPs serve as antibacterial agents, provide platforms to immobilize endotoxin adsorbents, interact with inflammatory cells to restore homeostasis and detect biomarkers of sepsis for timely diagnosis. This review discusses the recent developments in NP-based approaches for the treatment of sepsis.

Bifidobacterium longum Suppresses Murine Colorectal Cancer through the Modulation of oncomiRs and Tumor Suppressor miRNAs

The modulatory role of the Bifidobacterium longum (BL), isolated from women breast milk, on some oncogenic and tumor suppressor miRNAs as well as IL-1β and IL6 targeted-miRNAs was investigated using murine colorectal cancer (CRC) induced on the top of inflammatory ulcerative colitis model. The investigation of the oncomiRs miR-21a and miR-155, which regulate IL-6 and IL-1β expression, indicated that both was depressed by BL-administration in healthy and in CRC-mice. BL-administration induced the tumor suppressor miRNAs (miR-145 and miR-15a) expression in both of the healthy and in CRC-mice. The miR-146a expression, which regulates both of IL-1β and IL-6 expression, was decreased after the BL-administration in both of the healthy and in CRC-mice. In CRC-mice, NF-Kb concentration was elevated, however this NF-Kb induction was diminished after the treatment with BL. BL highly enhanced the IL-1β and IL-6 mRNA and protein concentrations in healthy mice. The administration of BL to CRC-mice resulted in a dramatic increase in IL-1β mRNA and IL-1β concentration, which in contrast was accompanied with a decrease in the IL-6 mRNA and IL-6 concentration. BL-administration resulted in a drop in the aberrant crypt foci number in CRC-mice and increased necrosis and fibrosis of the colon cells. The modulatory influence of B. longum on microRNAs may provide an important therapeutic impact in CRC through inhibition of the proliferation, invasion, apoptosis, and cell cycle of tumor cells.

Data-independent acquisition-based quantitative proteomic analysis reveals differences in host immune response of peripheral blood mononuclear cells to sepsis

This study was aimed to uncover proteins that are differentially expressed in sepsis. Data-independent acquisition (DIA) was used for analysis to identify differentially expressed proteins in peripheral blood mononuclear cells (PBMCs) of patients. A total of 24 non-septic intensive care unit (ICU) patients, 11 septic shock patients and 27 patients diagnosed with sepsis were recruited for the mass spectrometry (MS) discovery. PBMCs were isolated from routine blood samples and digested into peptides. A DIA workflow was developed using a quadrupole-Orbitrap liquid chromatography LC-MS system, and mass spectra peaks were extracted by Skyline software. Orthogonal partial least-squares discriminant analysis (OPLS-DA) and partial least-squares discriminant analysis (PLS-DA) were applied to distinguish the patient groups at the level of fragment ion and peptide. Differentially expressed proteins in the patient groups were verified by enzyme-linked immunosorbent assay (ELISA). Receiver-operating characteristic (ROC) curves were used to evaluate the protein expression. A total of 1062 fragment ions and 122 proteins were identified in the MS-DIA analysis conducted by Skyline software. Using gene ontology clustering analysis, we discovered that 51 of the 122 identified proteins were associated with biological processes, including carbon metabolism, biosynthesis of antibiotics, platelet activation, bacterial invasion of epithelial cells and complement, and coagulation cascades. Among them, five proteins (high-mobility group box1 [HMGB1], matrix metalloproteinase 8 [MMP8], neutrophil gelatinase-associated lipocalin [NGAL], lactotransferrin [LTF] and grancalcin [GCA]) were identified by ELISA as closely related to the development of sepsis. The ROC curves displayed good sensitivity and specificity.

Could a blood test for PTSD and depression be on the horizon?

INTRODUCTION

Depression and posttraumatic stress disorder (PTSD) are two complex and debilitating psychiatric disorders that result in poor life and destructive behaviors against self and others. Currently, diagnosis is based on subjective rather than objective determinations leading to misdiagnose and ineffective treatments. Advances in novel neurobiological methods have allowed assessment of promising biomarkers to diagnose depression and PTSD, which offers a new means of appropriately treating patients. Areas covered: Biomarkers discovery in blood represents a fundamental tool to predict, diagnose, and monitor treatment efficacy in depression and PTSD. The potential role of altered HPA axis, epigenetics, NPY, BDNF, neurosteroid biosynthesis, the endocannabinoid system, and their function as biomarkers for mood disorders is discussed. Insofar, we propose the identification of a biomarker axis to univocally identify and discriminate disorders with large comorbidity and symptoms overlap, so as to provide a base of support for development of targeted treatments. We also weigh in on the feasibility of a future blood test for early diagnosis. Expert commentary: Potential biomarkers have already been assessed in patients' blood and need to be further validated through multisite large clinical trial stratification. Another challenge is to assess the relation among several interdependent biomarkers to form an axis that identifies a specific disorder and secures the best-individualized treatment. The future of blood-based tests for PTSD and depression is not only on the horizon but, possibly, already around the corner.

Protective role of down-regulated microRNA-31 on intestinal barrier dysfunction through inhibition of NF-κB/HIF-1α pathway by binding to HMOX1 in rats with sepsis

Background

Intestinal barrier dysfunction is a significant clinical problem, commonly developing in a variety of acute or chronic pathological conditions. Herein, we evaluate the effect of microRNA-31 (miR-31) on intestinal barrier dysfunction through NF-κB/HIF-1α pathway by targeting HMOX1 in rats with sepsis.

Methods

Male Sprague-Dawley rats were collected and divided into the sham group, and the cecum ligation and perforation group which was subdivided after CACO-2 cell transfection of different mimic, inhibitor, or siRNA. Levels of serum D-lactic acid, diamine oxidase and fluorescence isothiocyanate dextran, FITC-DX concentration, and bacterial translocation were detected. Superoxidedismutase (SOD) activity and malondialdehyde (MDA) content were evaluated using the colorimetric method and an automatic microplate reader, respectively. Additionally, the levels of tumor necrosis factor, interleukin (IL)-6, and IL-10 were tested using enzyme-linked immunosorbent assay. The expression of miR-31, HMOX1, NF-κB, HIF-1α, IκB, ZO-1 and Occludin were assessed by reverse transcription quantitative polymerase chain reaction and Western blot analysis.

Results

Inhibition of miR-31 decreased intestinal mucosal permeability and intestinal barrier function. The increased levels of miR-31 could cause oxidative damage and affect the expression of inflammatory factors in intestinal tissue of rats. HMOX1 was confirmed as a target gene of miR-31. MiR-31 affected intestinal mucosal permeability and intestinal barrier function, as well as oxidative damage and inflammation level by regulating HMOX1. Down-regulation of miR-31 inhibited NF-κB/HIF-1α pathway related genes by regulating HMOX1 expression. Furthermore, inhibition of miR-31 increased survival rates of rats.

Conclusion

Overall, the current study found that inhibition of miR-31 protects against intestinal barrier dysfunction through suppression of the NF-κB/HIF-1α pathway by targeting HMOX1 in rats with sepsis.

Differential Immune Phenotypes in Human Monocytes Induced by Non-Host-Adapted Salmonella enterica Serovar Choleraesuis and Host-Adapted S. Typhimurium

We studied the effects of two Salmonella enterica serovar Typhimurium (host-adapted) strains (14028 and 4/74) and three S Choleraesuis (non-host-adapted) strains (A50, A45, and B195) in human monocytes between 2 and 24 h postinfection (p.i.) to investigate whether differences in immune response may explain the much higher prevalence of sepsis in individuals infected with S Choleraesuis. Both serovars significantly increased the production of cytokines associated with acute sepsis (tumor necrosis factor alpha [TNF-α], interleukin β [IL-β], and IL-6), but temporal differences occurred between these serovars and between different S Choleraesuis strains. Generally, all S Choleraesuis strains induced significantly higher production of inflammatory cytokines than S Typhimurium strains (P < 0.01 to 0.05). All S Choleraesuis strains very significantly increased IL-10 production by monocytes at 6 and 24 h p.i. in comparison to S Typhimurium strains (P < 0.01). In addition, ∼80% of monocytes were viable at 24 h p.i. with S Choleraesuis A50, compared to only ∼40% following S Typhimurium infection. Using S Typhimurium 14028 and S Choleraesuis A50 as examples of these two serovars, we also showed differential expression of genes within the Janus tyrosine kinase (JAK) and signal transducer and activator of transcription (STAT) (JAK/STAT) pathway via quantitative PCR (qPCR) microarray analysis. High serum IL-10 concentration and monocyte survival have been reported as markers of the development of human sepsis. We therefore conclude that high production of IL-10 by monocytes may, in part, explain the greater propensity for S Choleraesuis to induce human sepsis and that this may be greater in strains such as A50, which induces both high IL-10 production and monocyte survival.

The relationships among monocyte subsets, miRNAs and inflammatory cytokines in patients with acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) causes irreversible myocardial damage and release of inflammatory mediators, including cytokines, chemokines and miRNAs. We aimed to investigate changes in the levels of cytokines (IL-6, TNF-α and IL-10), miRNAs profiles (miR-146 and miR-155) and distribution of different monocyte subsets (CD14++CD16-, CD14++CD16+, CD14+CD16++) in the acute and post-healing phases of AMI.

METHODS

In eighteen consecutive AMI patients (mean age 56.78 ± 12.4 years, mean left ventricle ejection fraction - LVEF: 41.9 ± 9.8%), treated invasively, monocyte subsets frequencies were evaluated (flow cytometry), cytokine concentrations were analyzed (ELISA) as well as plasma miRNAs were isolated twice - on admission and after 19.2 ± 5.9 weeks of follow-up. Measurements were also performed among healthy volunteers.

RESULTS

AMI patients presented significantly decreased frequencies of classical cells in comparison to healthy controls (median 71.22% [IQR: 64.4-79.04] vs. 84.35% [IQR: 81.2-86.7], p = 0.001) and higher percent of both intermediate and non-classical cells, yet without statistical significance (median 6.54% [IQR: 5.14-16.64] vs. 5.87% [IQR: 4.48-8.6], p = 0.37 and median 5.99% [IQR: 3.39-11.5] vs. 5.26% [IQR: 3.62-6.2], p = 0.42, respectively). In AMI patients both, analyzed plasma miRNA concentrations were higher than in healthy subjects (miR-146: median 5.48 [IQR: 2.4-11.27] vs. 1.84 [IQR: 0.87-2.53], p = 0.003; miR-155: median 25.35 [IQR: 8.17-43.15] vs. 8.4 [IQR: 0.08-16.9], p = 0.027, respectively), and returned back to the values found in the control group in follow-up. miR-155/miR-146 ratio correlated with the frequencies of classical monocytes (r=0.6, p = 0.01) and miR-155 correlated positively with the concentration of inflammatory cytokines - IL-6 and TNF-α.

CONCLUSIONS

These results may suggest cooperation of both pro-inflammatory and anti-inflammatory signals in AMI in order to promote appropriate healing of the infarcted myocardium.

MicroRNA‑143 increases cell apoptosis in myelodysplastic syndrome through the Fas/FasL pathway both in vitro and in vivo

Whilst the role of microRNA‑143 (miR‑143) in myelodysplastic syndrome (MDS) remains unclear, abnormally expressed microRNA‑143 has been detected in many types of cancer tissues. In this study, we describe a cohort study for the verification of miR‑143 expression, as well as the investigation of the molecular mechanisms of miR‑143 in MDS/acute myeloid leukaemia (AML). In a series of experiments, miR‑143 recombinant lentiviral vectors transformed into SKM‑1 cells were either overexpressed or knocked down, and the results illustrated that the overexpression of miR‑143 inhibited SKM‑1 cell growth, arrested the SKM‑1 cells in the G0/G1 phase, interfered with cell proliferation and induced cell apoptosis via the Fas/FasL pathway. Conversely, miR‑143 knockdown induced a decrease in the apoptosis and promoted the proliferation of SKM‑1 cells. Moreover, miR‑143 was shown to suppress MLLT3/AF9 expression by binding to its 3'‑UTR. Taken together, the findings of this study indicate that miR‑143 may be a critical regulator of MDS/AML cell carcinogenesis, acting as a potent antitumour molecular target for the diagnosis or treatment of cancers associated with the abnormal expression of MLLT3/AF9, hence facilitating the development of potential therapeutics against MDS/AML.

Upregulation of microRNA-351 exerts protective effects during sepsis by ameliorating skeletal muscle wasting through the Tead-4-mediated blockade of the Hippo signaling pathway

Sepsis-induced skeletal muscle wasting may lead to various severe clinical consequences. Understanding molecular mechanisms of the regulation of the loss of skeletal muscle mass in septic patients remains a significant clinical challenge. The current study was conducted to establish septic mice models to explore the relationship between microRNA (miR)-351 and the transcription element apical (TEA) domain transcription factor (Tead)-4 gene and to investigate its effects on the skeletal muscle through mediating the Hippo signaling pathway in mice with acute sepsis. A total of 60 mice were collected to establish mouse models of acute sepsis. The positive expression rate of Tead-4 and the apoptotic index (AI) were measured. A dual-luciferase reporter gene assay was conducted to verify the targeting relationship between miR-351 and Tead-4. Furthermore, the muscle fiber diameter (MFD) and area (MFA) and the content of 3-methylhistidine (3-MH) and tyrosine (Tyr) were assessed. The expression levels of miR-351, p38-MAPK, Yes-associated protein, Tead-4, B-cell lymphoma X protein (Bax), and Caspase-3 were determined with quantitative RT-PCR and Western blot analysis. Finally, cell viability, apoptosis, and levels of inflammatory factors, including IL-1β, IL-6, IGF-1, TNF-α, and monocyte chemoattractant protein-1 were detected by 3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and ELISA. Initially, Tead-4 protein expression was higher in skeletal muscle tissues of mice with acute sepsis. Tead-4 was identified to negatively regulate miR-351. Upregulation of miR-351 increased MFA and MFD, muscle weight water content, Bcl-2 expression levels, and cell viability. Up-regulation of miR-351 reduced AI; 3-MH and Tyr content; positive expression of Tead-4 protein; the expression levels of p38-MAPK, Yap, Tead-4, Bax, and Caspase-3; apoptosis; and inflammatory responses. The current study demonstrated that up-regulation of miR-351 inhibits the degradation of skeletal muscle protein and the atrophy of skeletal muscle in mice with acute sepsis by targeting Tead-4 through suppression of the Hippo signaling pathway. Thus, miR-351 overexpression may be a future therapeutic strategy for acute sepsis.-Zhang, L.-N., Tian, H., Zhou, X.-L., Tian, S.-C., Zhang, X.-H., Wu, T.-J. Upregulation of microRNA-351 exerts protective effects during sepsis by ameliorating skeletal muscle wasting through the Tead-4-mediated blockade of the Hippo signaling pathway.

Nucleic-acid based gene therapy approaches for sepsis

Despite advances in overall medical care, sepsis and its sequelae continue to be an embarrassing clinical entity with an unacceptably high mortality rate. The central reason for high morbidity and high mortality of sepsis and its sequelae is the lack of an effective treatment. Previous clinical trials have largely failed to identify an effective therapeutic target to improve clinical outcomes in sepsis. Thus, the key goal favoring the outcome of septic patients is to devise innovative and evolutionary therapeutic strategies. Gene therapy can be considered as one of the most promising novel therapeutic approaches for nasty disorders. Since a number of transcription factors, such as nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), play a pivotal role in the pathophysiology of sepsis that can be characterized by the induction of multiple genes and their products, sepsis may be regarded as a gene-related disorder and gene therapy may be considered a promising novel therapeutic approach for treatment of sepsis. In this review article, we provide an up-to-date summary of the gene-targeting approaches, which have been developed in animal models of sepsis. Our review sheds light on the molecular basis of sepsis pathology for the development of novel gene therapy approaches and leads to the conclusion that future research efforts may fully take into account gene therapy for the treatment of sepsis.

Characterization of Human Type C Enterotoxin Produced by Clinical S. epidermidis Isolates

Staphylococcal Enterotoxins (SEs) are superantigens (SAg) originally produced by S. aureus, but their presence in coagulase negative staphylococci (CNS) has long been suspected. This study aims to better characterize a novel C-like enterotoxin expressed by clinical S. epidermidis strains, called SEC_epi. We isolated and characterized SEC_epi for its molecular and functional properties. The toxin was structurally modeled according to its significant similarity with S. aureus SEC3. Most of SEC amino acid residues important for the formation of the trimolecular Major Histocompatibility Complex II MHCII-SEC-T Cell Receptor TCR complex are conserved in SEC_epi. The functional properties of SEC_epi were estimated after cloning, expression in E. coli, and purification. The recombinant SEC_epi toxin exhibits biological characteristics of a SAg including stimulation of human T-cell mitogenicity, inducing and releasing high cytokines levels: IL-2, -4, -6, -8, -10, IFN-γ, TNF-α and GM-CSF at a dose as low as 3.7 pM. Compared to SEC_aureus, the production of pro-sepsis cytokine IL-6 is significantly higher with SEC_epi-activated lymphocytes. Furthermore, SEC_epi is stable to heat, pepsin or trypsin hydrolysis. The SEC_epi superantigen produced by CNS is functionally very close to that of S. aureus, possibly inducing a systemic inflammatory response at least comparable to that of SEC_aureus, and may account for S. epidermidis pathogenicity.