Sepsis plasma-derived exosomal miR-1-3p induces endothelial cell dysfunction by targeting SERP1

Dexmedetomidine mitigates lipopolysaccharide-induced acute lung injury by modulating heat shock protein A12B to inhibit the toll-like receptor 4/nuclear factor-kappa B signaling pathway

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS): Life-threatening medical conditions characterized by high morbidity and mortality rates, where the inflammatory process plays a crucial role in lung tissue damage, especially in models induced by lipopolysaccharide (LPS). Heat shock protein A12B (HSPA12B) has strong anti-infammatory properties However, it is unknown whether increased HSPA12B is protective against LPS-induced ALI. And Dexmedetomidine (DEX) is a potent α2-adrenergic receptor (α2-AR) agonist that has been shown to protect against sepsis-induced lung injury, however, the underlying mechanisms of this protection are not fully understood. This study utilized bioinformatics analysis and an LPS-induced ALI model to explore how DEX alleviates lung injury by modulating HSPA12B and inhibiting the Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway. Results indicate that HSPA12B overexpression and DEX pre-treatment markedly mitigated LPS-induced lung injury, which was evaluated by the deterioration of histopathology, histologic scores, the W/D weight ratio, and total protein expression, tumor necrosis factor-alpha (TNF-α), and interleukin-1β (IL-1β) in the BALF, and the levels of NO, MDA,SOD and MPO in the lung. Moreover, HSPA12B overexpression and DEX pre-treatment significantly reduces lung injury and inflammation levels by upregulating HSPA12B and inhibiting the activation of the TLR4/NF-κB signaling pathway. On the contrary, when the expression of HSPA12B is inhibited, the protective effect of DEX pre-treatment on lung tissue is significantly weakened.In summary, our research demonstrated that the increased expression of AAV-mediated HSPA12B in the lungs of mice inhibits acute inflammation and suppresses the activation of TLR4/NF-κB pathway in a murine model of LPS-induced ALI. DEX could enhance HSPA12B and inhibit the initiation and development of inflammation through down-regulating TLR4/NF-κB pathway.These findings highlight the potential of DEX as a therapeutic agent for treating ALI and ARDS, offering new strategies for clinical intervention.

Exosome-Derived microRNA: Potential Target for Diagnosis and Treatment of Sepsis

Exosome-derived microRNAs (miRNAs) are emerging as pivotal players in the pathophysiology of sepsis, representing a new frontier in both the diagnosis and treatment of this complex condition. Sepsis, a severe systemic response to infection, involves intricate immune and nonimmune mechanisms, where exosome-mediated communication can significantly influence disease progression and outcomes. During the progress of sepsis, the miRNA profile of exosomes undergoes notable alterations, is reflecting, and may affect the progression of the disease. This review comprehensively explores the biology of exosome-derived miRNAs, which originate from both immune cells (such as macrophages and dendritic cells) and nonimmune cells (such as endothelial and epithelial cells) and play a dynamic role in modulating pathways that affect the course of sepsis, including those related to inflammation, immune response, cell survival, and apoptosis. Taking into account these dynamic changes, we further discuss the potential of exosome-derived miRNAs as biomarkers for the early detection and prognosis of sepsis and advantages over traditional biomarkers due to their stability and specificity. Furthermore, this review evaluates exosome-based therapeutic miRNA delivery systems in sepsis, which may pave the way for targeted modulation of the septic response and personalized treatment options.

Peripheral inflammation as a potential mechanism and preventive strategy for perioperative neurocognitive disorder under general anesthesia and surgery

General anesthesia, as a commonly used medical intervention, has been widely applied during surgical procedures to ensure rapid loss of consciousness and pain relief for patients. However, recent research suggests that general anesthesia may be associated with the occurrence of perioperative neurocognitive disorder (PND). PND is characterized by a decline in cognitive function after surgery, including impairments in attention, memory, learning, and executive functions. With the increasing trend of population aging, the burden of PND on patients and society's health and economy is becoming more evident. Currently, the clinical consensus tends to believe that peripheral inflammation is involved in the pathogenesis of PND, providing strong support for further investigating the mechanisms and prevention of PND.

UNVEILING THE PROTECTIVE MECHANISMS OF PUERARIN AGAINST ACUTE LUNG INJURY: A COMPREHENSIVE EXPLORATION OF THE ROLES AND MECHANISMS OF MST1/ERS SIGNALING

ABSTRACT

Objectives: Puerarin, the principal active constituent extracted from Pueraria, is believed to confer protection against sepsis-induced lung injury. The study aimed to elucidate the role and mechanism of Mst1/ERS in puerarin-mediated protection against acute lung injury (ALI). Methods: Monolayer vascular endothelial cell permeability was assessed by gauging the paracellular flow of FITC-dextran 40,000 (FD40). ELISA was employed for the quantification of inflammatory cytokines. Identification of target proteins was conducted through western blotting. Histological alterations and apoptosis were scrutinized using hematoxylin-eosin staining and TUNEL staining, respectively. The ultrastructure of the endoplasmic reticulum was observed via transmission electron microscopy. Results: Puerarin significantly protected mice from LPS-induced ALI, reducing lung interstitial width, neutrophil and lymphocyte infiltration, pulmonary interstitial and alveolar edema, and lung apoptosis. Puerarin treatment also markedly attenuated levels of TNF-α and IL-1β in both alveolar lavage fluid and serum. Furthermore, puerarin significantly attenuated LPS-induced increases in Mst1, GRP78, CHOP, and Caspase12 protein expression and blunted LPS-induced decrease in ZO-1 protein expression in lung tissues. Puerarin obviously reduced endoplasmic reticulum expansion and vesiculation. Similarly, puerarin significantly mitigated the LPS-induced reduction in HUVEC cell viability and ZO-1 expression. Puerarin also attenuated LPS-induced increase in apoptosis, TNF-α and IL-1β, FD40 flux, and Mst1, GRP78, CHOP, and Caspase12 expression in HUVEC cells. Nevertheless, the inhibitory impact of puerarin on vascular endothelial cell injury, lung injury, and endoplasmic reticulum stress (ERS) was diminished by Mst1 overexpression. Conclusion: These findings demonstrated that the Mst1/ERS signaling pathway played a pivotal role in the development of LPS-induced vascular endothelial cell dysfunction and ALI. Puerarin exhibited the ability to attenuate LPS-induced vascular endothelial cell dysfunction and ALI by inhibiting the Mst1/ERS signaling pathway.

Protective Effect and Mechanism of Autophagy in Endothelial Cell Injury Induced by Hyperoxia

OBJECTIVE

Bronchopulmonary dysplasia is a chronic lung disease in premature infants with alveolar simplification and pulmonary vascular development disorder as the main pathological feature and hyperoxia as the main etiology. Autophagy is a highly conserved cytological behavior of self-degrading cellular components and is accompanied by oxidative stress. Studies have reported that autophagy is regulated by FOXO1 posttranslational modification. However, whether autophagy can be involved in the regulation of endothelial cell injury induced by hyperoxia and its mechanism are still unclear.

STUDY DESIGN

We have activated and inhibited autophagy in human umbilical vein endothelial cells under hyperoxia and verified the role of autophagy in endothelial cell-related functions from both positive and negative aspects.

RESULTS

Our research showed that the expression level of autophagy-related proteins decreased, accompanied by decreased cell migration ability and tube formation ability and increased cell reactive oxygen species level and cell permeability under hyperoxia conditions. Using an autophagy agonist alleviated hyperoxia-induced changes and played a protective role. However, inhibition of autophagy aggravated the cell damage induced by hyperoxia. Moreover, the decrease in autophagy proteins was accompanied by the upregulation of FOXO1 phosphorylation and acetylation.

CONCLUSION

We concluded that autophagy was a protective mechanism against endothelial cell injury caused by hyperoxia. Autophagy might participate in this process by coregulating posttranslational modifications of FOXO1.

KEY POINTS

· Hyperoxia induces vascular endothelial cell injury.. · Autophagy may has a protective role under hyperoxia conditions.. · FOXO1 posttranslational modification may be involved in the regulation of autophagy..

Unveiling the Role of Exosomes in the Pathophysiology of Sepsis: Insights into Organ Dysfunction and Potential Biomarkers

Extracellular vesicles (EVs) are tools for intercellular communication, mediating molecular transport processes. Emerging studies have revealed that EVs are significantly involved in immune processes, including sepsis. Sepsis, a dysregulated immune response to infection, triggers systemic inflammation and multi-organ dysfunction, posing a life-threatening condition. Although extensive research has been conducted on animals, the complex inflammatory mechanisms that cause sepsis-induced organ failure in humans are still not fully understood. Recent studies have focused on secreted exosomes, which are small extracellular vesicles from various body cells, and have shed light on their involvement in the pathophysiology of sepsis. During sepsis, exosomes undergo changes in content, concentration, and function, which significantly affect the metabolism of endothelia, cardiovascular functions, and coagulation. Investigating the role of exosome content in the pathogenesis of sepsis shows promise for understanding the molecular basis of human sepsis. This review explores the contributions of activated immune cells and diverse body cells' secreted exosomes to vital organ dysfunction in sepsis, providing insights into potential molecular biomarkers for predicting organ failure in septic shock.

Cuproptosis-Related Biomarkers and Characterization of Immune Infiltration in Sepsis

Introduction

Sepsis is a worldwide epidemic, with high morbidity and mortality. Cuproptosis is a form of cell death that is associated with a wide range of diseases. This study aimed to explore genes associated with cuproptosis in sepsis, construct predictive models and screen for potential targets.

Methods

The LASSO algorithm and SVM-RFE model has been analysed the expression of cuproptosis-related genes in sepsis and immune infiltration characteristics and identified the marker genes under a diagnostic model. Gene-drug networks, mRNA-miRNA networks and PPI networks were constructed to screen for potential biological targets. The expression of marker genes was validated based on the GSE57065 dataset. Consensus clustering method was used to classify sepsis samples.

Results

We found 381 genes associated with the development of sepsis and discovered significantly differentially expressed cuproptosis-related genes of 16 cell types in sepsis and immune infiltration with CD8/CD4 T cells being lower. NFE2L2, NLRP3, SLC31A1, DLD, DLAT, PDHB, MTF1, CDKN2A and DLST were identified as marker genes by the LASSO algorithm and the SVM-RFE model. AUC > 0.9 was constructed for PDHB and MTF1 alone respectively. The validation group data for PDHB (P=0.00099) and MTF1 (P=7.2e-14) were statistically significant. Consistent clustering analysis confirmed two subtypes. The C1 subtype may be more relevant to cellular metabolism and the C2 subtype has some relevance to immune molecules.The results of animal experiments showed that the gene expression was consistent with the bioinformatics analysis.

Discussion

Our study systematically explored the relationship between sepsis and cuproptosis and constructed a diagnostic model. And, several cuproptosis-related genes may interfere with the progression of sepsis through immune cell infiltration.

Identification of common genes and pathways between type 2 diabetes and COVID-19

Background

Numerous studies have reported a high incidence and risk of severe illness due to coronavirus disease 2019 (COVID-19) in patients with type 2 diabetes (T2DM). COVID-19 patients may experience elevated or decreased blood sugar levels and may even develop diabetes. However, the molecular mechanisms linking these two diseases remain unclear. This study aimed to identify the common genes and pathways between T2DM and COVID-19.

Methods

Two public datasets from the Gene Expression Omnibus (GEO) database (GSE95849 and GSE164805) were analyzed to identify differentially expressed genes (DEGs) in blood between people with and without T2DM and COVID-19. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on the common DEGs. A protein-protein interaction (PPI) network was constructed to identify common genes, and their diagnostic performance was evaluated by receiver operating characteristic (ROC) curve analysis. Validation was performed on the GSE213313 and GSE15932 datasets. A gene co-expression network was constructed using the GeneMANIA database to explore interactions among core DEGs and their co-expressed genes. Finally, a microRNA (miRNA)-transcription factor (TF)-messenger RNA (mRNA) regulatory network was constructed based on the common feature genes.

Results

In the GSE95849 and GSE164805 datasets, 81 upregulated genes and 140 downregulated genes were identified. GO and KEGG enrichment analyses revealed that these DEGs were closely related to the negative regulation of phosphate metabolic processes, the positive regulation of mitotic nuclear division, T-cell co-stimulation, and lymphocyte co-stimulation. Four upregulated common genes (DHX15, USP14, COPS3, TYK2) and one downregulated common feature gene (RIOK2) were identified and showed good diagnostic accuracy for T2DM and COVID-19. The AUC values of DHX15, USP14, COPS3, TYK2, and RIOK2 in T2DM diagnosis were 0.931, 0.917, 0.986, 0.903, and 0.917, respectively. In COVID-19 diagnosis, the AUC values were 0.960, 0.860, 1.0, 0.9, and 0.90, respectively. Validation in the GSE213313 and GSE15932 datasets confirmed these results. The miRNA-TF-mRNA regulatory network showed that TYH2 was targeted by PITX1, PITX2, CRX, NFYA, SREBF1, RELB, NR1L2, and CEBP, whereas miR-124-3p regulates THK2, RIOK2, and USP14.

Conclusion

We identified five common feature genes (DHX15, USP14, COPS3, TYK2, and RIOK2) and their co-regulatory pathways between T2DM and COVID-19, which may provide new insights for further molecular mechanism studies.

Extracellular vesicles and endothelial dysfunction in infectious diseases

Cardiovascular diseases (CVDs) remain the leading cause of mortality and morbidity globally. Studies have shown that infections especially bacteraemia and sepsis are associated with increased risks for endothelial dysfunction and related CVDs including atherosclerosis. Extracellular vesicles (EVs) are small, sealed membrane-derived structures that are released into body fluids and blood from cells and/or microbes and are critically involved in a variety of important cell functions and disease development, including intercellular communications, immune responses and inflammation. It is known that EVs-mediated mechanism(s) is important in the development of endothelial dysfunction in infections with a diverse spectrum of microorganisms including Escherichia coli, Candida albicans, SARS-CoV-2 (the virus for COVID-19) and Helicobacter pylori. H. pylori infection is one of the most common infections globally. During H. pylori infection, EVs can carry H. pylori components, such as lipopolysaccharide, cytotoxin-associated gene A, or vacuolating cytotoxin A, and transfer these substances into endothelial cells, triggering inflammatory responses and endothelial dysfunction. This review is to illustrate the important role of EVs in the pathogenesis of infectious diseases, and the development of endothelial dysfunction in infectious diseases especially H. pylori infection, and to discuss the potential mechanisms and clinical implications.

Exploring ncRNA-mediated pathways in sepsis-induced pyroptosis

Sepsis, a potentially fatal illness caused by an improper host response to infection, remains a serious problem in the world of healthcare. In recent years, the role of ncRNA has emerged as a pivotal aspect in the intricate landscape of cellular regulation. The exploration of ncRNA-mediated regulatory networks reveals their profound influence on key molecular pathways orchestrating pyroptotic responses during septic conditions. Through a comprehensive analysis of current literature, we navigate the diverse classes of ncRNAs, including miRNAs, lncRNAs, and circRNAs, elucidating their roles as both facilitators and inhibitors in the modulation of pyroptotic processes. Furthermore, we highlight the potential diagnostic and therapeutic implications of targeting these ncRNAs in the context of sepsis, aiming to cover the method for novel and effective strategies to mitigate the devastating consequences of septic pathogenesis. As we unravel the complexities of this regulatory axis, a deeper understanding of the intricate crosstalk between ncRNAs and pyroptosis emerges, offering promising avenues for advancing our approach to sepsis intervention. The intricate pathophysiology of sepsis is examined in this review, which explores the dynamic interaction between ncRNAs and pyroptosis, a highly regulated kind of programmed cell death.

The efficacy of extracellular vesicles for acute lung injury in preclinical animal models: a meta-analysis

BACKGROUND

With the increasing research on extracellular vesicles (EVs), EVs have received widespread attention as biodiagnostic markers and therapeutic agents for a variety of diseases. Stem cell-derived EVs have also been recognized as a new viable therapy for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). To assess their efficacy, we conducted a meta-analysis of existing preclinical experimental animal models of EVs for ALI treatment.

METHODS

The database was systematically interrogated for pertinent data encompassing the period from January 2010 to April 2022 concerning interventions involving extracellular vesicles (EVs) in animal models of acute lung injury (ALI). The lung injury score was selected as the primary outcome measure for statistical analysis. Meta-analyses were executed utilizing RevMan 5.3 and State15.1 software tools.

RESULTS

The meta-analyses comprised 31 studies, exclusively involving animal models of acute lung injury (ALI), categorized into two cohorts based on the presence or absence of extracellular vesicle (EV) intervention. The statistical outcomes from these two study groups revealed a significant reduction in lung injury scores with the administration of stem and progenitor cell-derived EVs (SMD = -3.63, 95% CI [-4.97, -2.30], P < 0.05). Conversely, non-stem cell-derived EVs were associated with an elevation in lung injury scores (SMD = -4.34, 95% CI [3.04, 5.63], P < 0.05). EVs originating from stem and progenitor cells demonstrated mitigating effects on alveolar neutrophil infiltration, white blood cell counts, total cell counts in bronchoalveolar lavage fluid (BALF), lung wet-to-dry weight ratios (W/D), and total protein in BALF. Furthermore, pro-inflammatory mediators exhibited down-regulation, while anti-inflammatory mediators demonstrated up-regulation. Conversely, non-stem cell-derived EVs exacerbated lung injury.

CONCLUSION

In preclinical animal models of acute lung injury (ALI), the administration of extracellular vesicles (EVs) originating from stem and progenitor cells demonstrably enhances pulmonary function. This ameliorative effect is attributed to the mitigation of pulmonary vascular permeability and the modulation of immune homeostasis, collectively impeding the progression of inflammation. In stark contrast, the utilization of EVs derived from non-stem progenitor cells exacerbates the extent of lung injury. These findings substantiate the potential utility of EVs as a novel therapeutic avenue for addressing acute lung injury.

An overview of the mechanisms and potential roles of extracellular vesicles in septic shock

Septic shock, a subset of sepsis, is a fatal condition associated with high morbidity and mortality. However, the pathophysiology of septic shock is not fully understood. Moreover, the diagnostic markers employed for identifying septic shock lack optimal sensitivity and specificity. Current treatment protocols for septic shock have not been effective in lowering the mortality rate of patients. Most cells exhibit the capability to release extracellular vesicles (EVs), nanoscale vesicles that play a vital role in intercellular communication. In recent years, researchers have investigated the potential role of EVs in the pathogenesis, diagnosis, and treatment of different diseases, such as oncological, neurological, and cardiovascular diseases, as well as diabetes and septic shock. In this article, we present an overview of the inhibitory and facilitative roles that EVs play in the process of septic shock, the potential role of EVs in the diagnosis of septic shock, and the potential therapeutic applications of both native and engineered EVs in the management of septic shock.

Molecular Mechanism of SOX18 in Lipopolysaccharide-Induced Injury of Human Umbilical Vein Endothelial Cells

Endothelial dysfunction is associated with the progression of sepsis. This study sought to probe the molecular route of sex-determining region on the Y chromosome-box transcription factor 18 (SOX18) in sepsis-associated endothelial injury. Human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) to establish the sepsis cell model. Cell viability, lactate dehydrogenase (LDH) release, oxidative stress (reactive oxygen species/malondialdehyde/superoxide dismutase), and inflammation (interleukin-1β/tumor necrosis factor-α/interleukin-6) were evaluated by cell counting kit-8 assay and relevant assay kits. The expression levels of SOX18, microRNA (miR)-204-5p, and cadherin-2 (CDH2) in cells were determined by real-time quantitative polymerase chain reaction and Western blot assay. The interaction of SOX18, miR-204-5p, and CDH2 was analyzed by chromatin immunoprecipitation and dual-luciferase assay. LPS induced HUVECs injury and downregulation of SOX18. SOX18 overexpression increased cell viability, while decreased LDH activity, oxidative stress, and inflammation. SOX18 bound to the miR-204-5p promoter to promote miR-204-5p expression, and further repressed CDH2 expression. miR-204-5p knockdown and CDH2 overexpression abrogated the protective role of SOX18 in HUVECs injury. Overall, SOX18 alleviated LPS-induced injury of HUVECs by promoting miR-204-5p and repressing CDH2, suggesting it as a potential target for sepsis treatment.

TMEM16A deficiency in alveolar type 2 epithelial cells protected against endoplasmic reticulum stress-induced ferroptosis during acute lung injury

Transmembrane protein 16A (TMEM16A) is one of the members of the ten-member family of "transmembrane protein 16", playing critical roles in infection and solid organ injury. Acute lung injury (ALI) is a devastating disease which could be triggered by sepsis, trauma, and ischemia reperfusion. However, molecular mechanisms contributing to ALI are poorly understood at presently. In this study, we investigated the role of TMEM16A in sepsis-induced ALI using TMEM16A-deficient mice. Sepsis-induced ALI model was established by intratracheal injection of lipopolysaccharide (LPS). Our results showed that LPS stimulation significantly upregulated the expression levels of TMEM16A in lung tissues and in alveolar epithelial type II (AT2) cells. Knockout of TMEM16A in AT2 cells significantly improved pulmonary function and alleviated lung pathological injury in LPS-treated mice. Meanwhile, TMEM16A deficiency also inhibited endoplasmic reticulum (ER) stress and ferroptosis in AT2 cells from LPS-treated mice. In vitro experiments further demonstrated that ER stress and ferroptosis were inhibited after TMEM16A was knocked out. Furthermore, we used ER stress inducer thapsigargin to induce ER stress in TMEM16A-null AT2 cells and found that the induction of ER stress abolished the inhibition of ferroptosis by TMEM16A deficiency in LPS-treated AT2 cells. Finally, we disclosed that pharmacological inhibition of TMEM16A by shikonin also showed similar therapeutic effect on LPS-induced ALI in vivo. In conclusion, TMEM16A deficiency in AT2 cells could alleviate sepsis-induced ALI by decreasing ER stress-induced ferroptosis during ALI.

Study on identification of a three-microRNA panel in serum for diagnosing neonatal early onset sepsis

BACKGROUND

Comparing with other diseases, early onset sepsis (EOS) is a global health concern in neonatal period for its high morbidity and mortality rates. In recent years, many studies have contributed to the figure out the expression patterns of circulating micro-RNAs (miRNAs) in different diseases and progressions, which could function as diagnostic biomarkers for EOS. The purpose of this study was to analyze the expression patterns of selected miRNAs and evaluate their diagnostic value for early detection and treatment.

METHODS

This was a prospective cross-sectional study conducted from 1 July 2021 to 30 June 2022. We collected surplus peripheral blood and demographic statistics of septic neonates and non-infected neonates during the first 24 h after delivery and obtained 11 candidate miRNAs by literature screening. First, we extracted the candidate miRNAs from the serum of selected neonates and analyzed their expression levels, and then the receiver operating characteristic (ROC) curve was used to select the differentially expressed miRNAs. We analyzed their sensitivity and specificity and obtained the best diagnostic panel. Finally, with the help of differentially expressed miRNAs, we performed gene ontology (GO) enrichment and protein-protein interaction (PPI) analyses by their target genes.

RESULTS

In patients with EOS, three miRNAs (mir-223-3p, mir-15a-5p, and mir-17-5p) in serum were significantly downregulated, and mir-146a-5p, mir-1-3p, and mir-16-5p were upregulated. The diagnostic value of these miRNAs (miR-15a-5p, AUC = 0.67; miR-223-3p, AUC = 0.72; miR-16-5p, AUC = 0.68; miR-17-5p, AUC = 0.70; miR-1-3p, AUC = 0.69; miR-146a-5p, AUC = 0.72) was moderate, and the diagnostic panel constructed by miR-15a-5p, miR-223-3p, and miR-16-5p possessed a comparatively higher diagnostic value (AUC = 0.85, sensitivity: 74.6%, specificity: 86%), indicating that their combined application may be a promising biomarker for clinical diagnosis of EOS. According to GO enrichment analysis, most proteins encoded by target genes were located in the cytosol as for cellular component (CC), for molecular function (MF), most proteins acted as regulators in protein binding, and for biological process (BP). Most genes function in positive or negative regulation of transcription from RNA polymerase II promoter, and the top 10 hub genes were CDKN1A, YAP1, CCNE1, CCND1, CKK6, ERBB4, CHEK1, DICER1, VEGFA, and APP by rank degree after PPI construction.

CONCLUSIONS

The three-miRNA panels (miR-15a-5p, miR-223-3p, and miR-16-5p) may be a novel noninvasive biological marker for EOS screening.

Exosomal miR-155-5p drives widespread macrophage M1 polarization in hypervirulent Klebsiella pneumoniae-induced acute lung injury via the MSK1/p38-MAPK axis

BACKGROUND

Hypervirulent Klebsiella pneumoniae (hvKp) infection-induced sepsis-associated acute lung injury (ALI) has emerged as a significant clinical challenge. Increasing evidence suggests that activated inflammatory macrophages contribute to tissue damage in sepsis. However, the underlying causes of widespread macrophage activation remain unclear.

METHODS

BALB/c mice were intravenously injected with inactivated hvKp (iHvKp) to observe lung tissue damage, inflammation, and M1 macrophage polarization. In vitro, activated RAW264.7 macrophage-derived exosomes (iHvKp-exo) were isolated and their role in ALI formation was investigated. RT-PCR was conducted to identify changes in exosomal miRNA. Bioinformatics analysis and dual-luciferase reporter assays were performed to validate MSK1 as a direct target of miR-155-5p. Further in vivo and in vitro experiments were conducted to explore the specific mechanisms involved.

RESULTS

iHvKp successfully induced ALI in vivo and upregulated the expression of miR-155-5p. In vivo, injection of iHvKp-exo induced inflammatory tissue damage and macrophage M1 polarization. In vitro, iHvKp-exo was found to promote macrophage inflammatory response and M1 polarization through the activation of the p38-MAPK pathway. RT-PCR revealed exposure time-dependent increased levels of miR-155-5p in iHvKp-exo. Dual-luciferase reporter assays confirmed the functional role of miR-155-5p in mediating iHvKp-exo effects by targeting MSK1. Additionally, inhibition of miR-155-5p reduced M1 polarization of lung macrophages in vivo, resulting in decreased lung injury and inflammation induced by iHvKp-exo or iHvKp.

CONCLUSIONS

The aforementioned results indicate that exosomal miR-155-5p drives widespread macrophage inflammation and M1 polarization in hvKp-induced ALI through the MSK1/p38-MAPK Axis.

miRNAs: novel noninvasive biomarkers as diagnostic and prognostic tools in neonatal sepsis

The study aimed to assess the diagnostic and prognostic value of 3 specific microRNAs (miRNAs) in early-onset neonatal sepsis (NS). We examined miR-1, miR-124, and miR-34a in 70 NS patients upon admission and compared them to 70 healthy controls by RT-PCR. The main finding of the study was the difference in miRNA expression levels between NS patients and controls. Higher expression levels of miR-1 and miR-124 were significantly associated with NS, while miR-34a expression was reduced. Among the studied miRNAs, miR-34a exhibited the highest specificity (97%) as a confirmatory test for NS. In the multivariate model, miR-1 and miR-124 were found to be significant predictors of disease progression or mortality. Overall, the study suggests that miR-1, miR-124, and miR-34a could serve as potential biomarkers for diagnosing and predicting outcomes in early-onset NS.

Extracellular Vesicles in Sepsis: Pathogenic Roles, Organ Damage, and Therapeutic Implications

Despite significant advances in anti-infective treatment and organ function support technology in recent years, the mortality rate of sepsis remains high. In addition to the high costs of sepsis treatment, the increasing consumption of medical resources also aggravates economic pressure and social burden. Extracellular vesicles (EVs) are membrane vesicles released from different types of activated or apoptotic cells to mediate intercellular communication, which can be detected in both human and animal body fluids. A growing body of researches suggest that EVs play an important role in the pathogenesis of sepsis. In this review, we summarize the predominant roles of EVs in various pathological processes during sepsis and its related organ dysfunction.

How Extracellular Nano-Vesicles Can Play a Role in Sepsis? An Evidence-Based Review of the Literature

Sepsis is a systemic inflammatory reaction caused by infection. Severe sepsis can lead to multiple organ dysfunction, with a high incidence rate and mortality. The molecular pathogenesis of sepsis is complex and diverse. In recent years, with further study of the role of extracellular vesicles (EVs) in inflammatory diseases, it has been found that EVs play a dual role in the imbalance of inflammatory response in sepsis. Due to the great advantages such as lower toxicity, lower immunogenicity compared with stem cells and better circulation stability, EVs are increasingly used for the diagnosis and treatment of sepsis. The roles of EVs in the pathogenesis, diagnosis and treatment of sepsis were summarized to guide further clinical studies.

Exosomal MicroRNAs: An Emerging Important Regulator in Acute Lung Injury

Acute lung injury (ALI) is a clinically life-threatening form of respiratory failure with a mortality of 30%-40%. Acute respiratory distress syndrome is the aggravated form of ALI. Exosomes are extracellular lipid vesicles ubiquitous in human biofluids with a diameter of 30-150 nm. They can serve as carriers to convey their internal cargo, particularly microRNA (miRNA), to the target cells involved in cellular communication. In disease states, the quantities of exosomes and the cargo generated by cells are altered. These exosomes subsequently function as autocrine or paracrine signals to nearby or distant cells, regulating various pathogenic processes. Moreover, exosomal miRNAs from multiple stem cells can provide therapeutic value for ALI by regulating different signaling pathways. In addition, changes in exosomal miRNAs of biofluids can serve as biomarkers for the early diagnosis of ALI. This study aimed to review the role of exosomal miRNAs produced by different sources participating in various pathological processes of ALI and explore their potential significance in the treatment and diagnosis.

IL-1β-pretreated bone mesenchymal stem cell-derived exosomes alleviate septic endoplasmic reticulum stress via regulating SIRT1/ERK pathway

Background

Endoplasmic reticulum (ER) plays a crucial role in the development of organ injury caused by sepsis. Therefore, it is highly important to devise strategies that specially target ER stress for the treatment of sepsis. Previous research has shown that priming chemokines can enhance the therapeutic effects of mesenchymal stem cells (MSCs). In this study, we aimed to investigate the function and mechanism of exosomes derived from MSCs that were pretreated with IL-1β (IB-exos) in the context of septic ER stress.

Methods

Mouse bone MSCs were preconditioned with or without IL-1β and the supernatant was used for exosome extraction. In vitro sepsis cell mode was induced by treating HUVECs with LPS, while in vivo sepsis model was established through cecal ligation and puncture (CLP) operation in mice. Cell viability, apoptosis, motility, and tube formation were assessed using the EDU proliferation assay, flow cytometry analysis, migration assay, and tube formation assay, respectively. The molecular mechanism was investigated using ELISA, qRT-PCR, Western blot, and immunofluorescence staining.

Results

Pretreatment with IL-1β enhanced the positive impact of MSC-exos on the viability, apoptosis, motility, and tube formation ability of HUVECs. The administration of LPS or CLP increased ER stress response, but this effect was blocked by the treatment of IB-exos. Additionally, IB-exos reversed the inhibitory effects of LPS or CLP on the expression levels of SIRT1 and ERK phosphorylation. Knockdown of SIRT1 counteracted the effects of IB-exos on HUVEC cellular function and ER stress. In a mouse model, the injection of IB-exos mitigated sepsis-induced lung injury by inhibiting ER stress response through the activation of SIRT1.

Conclusion

IB-exos have been found to alleviate sepsis-induced lung injury via inhibiting ER stress through the SIRT1/ERK pathway. These findings indicated that IB-exos could potentially be used as a strategy to mitigate lung injury caused by sepsis.

Clinical value of serum miR-1-3p as a potential circulating biomarker for abdominal aortic aneurysm

BACKGROUND

Although abdominal aortic aneurysm (AAA) is associated with life-threatening complications, there are still limited reliable biomarkers for diagnostic purpose. MicroRNAs (miRNAs) have been proposed as the potential diagnostic and risk stratification markers of AAA patients, and we aim to evaluate the serum level of miR-1-3p and its diagnostic value in AAA.

METHODS

This study included 200 AAA patients and 200 controls. Demographic data and clinical information were collected from the subjects' medical records. Individual image analyses of AAA morphology were determined based on computed tomography angiography (CTA). The levels of serum miRNA expression were detected by quantitative real-time PCR. Bioinformatics tools were used to identify the target genes of miR-1-3p and their potential biological functions were further enriched.

RESULTS

Serum miR-1-3p levels in the AAA group were significantly lower when compared with those in the control group in overall and subgroup comparisons. It was negatively related to WBC, CRP, maximal aneurysm diameter, area, and volume in AAA patients. Circulating miR-1-3p levels could significantly discriminate between AAA patients and healthy individuals with an area under the curve (AUC) of 0.672 (95% CI = 0.619-0.724, p < 0.001), a sensitivity of 84.5% and a specificity of 45.5%. Serum miR-1-3p was associated with a reduced risk of AAA even after adjustment for possible risk factors (OR = 0.440 per unit increase, 95% CI = 0.301-0.643, p < 0.001). And low levels of serum miR-1-3p could significantly elevate the risk of AAA in both univariate and multivariate logistic regression analyses with ORs of 4.076 and 4.136, respectively (all p < 0.001). Further GO enrichment analysis revealed that miR-1-3p was mainly involved in negative regulation of apoptotic process, sprouting angiogenesis, angiogenesis, positive regulation of blood vessel endothelial cell migration, positive regulation of cell proliferation, regulation of cell shape, etc.

CONCLUSIONS

MiR-1-3p can be used as a promising circulating biomarker in the development of AAA, and it may participate in multiple biological processes to play a crucial role in AAA pathogenesis.

Emerging functions and clinical applications of exosomal microRNAs in diseases

Exosomes are an important group of extracellular vesicles that transfer several kinds of biomolecules and facilitate cell-cell communication. The content of exosomes, particularly the amounts of microRNA (miRNAs) inside these vesicles, demonstrates a disease-specific pattern reflecting pathogenic processes and may be employed as a diagnostic and prognostic marker. miRNAs may enter recipient cells through exosomes and generate a RISC complex that can cause degradation of the target mRNAs or block translation of their corresponding proteins. Therefore, exosome-derived miRNAs constitute an important mechanism of gene regulation in recipient cells. The miRNA content of exosomes can be used as an important tool in the detection of diverse disorders, particularly cancers. This research field has an important situation in cancer diagnosis. In addition, exosomal microRNAs offer a great deal of promise in the treatment of human disorders. However, there are still certain challenges to be resolved. The most important challenges are as follow: the detection of exosomal miRNAs should be standardized, exosomal miRNAs-associated studies should be conducted in large number of clinical samples, and experiment settings and detection criteria should be consistent across different labs. The goal of this article is to present an overview of the effects of exosome-derived microRNAs on a variety of diseases, including gastrointestinal, pulmonary, neurological, and cardiovascular diseases, with a particular emphasis on malignancies.

Lung cancer-derived exosomal miR-132-3p contributed to interstitial lung disease development

PURPOSE

Interstitial lung diseases (ILDs) have high morbidity and mortality and poor prognosis. The significance of microRNAs (miRNAs) was highlighted in ILDs development. Currently, we attempted to confirm the functions of lung cancer-derived exosomal miR-132-3p and reveal the underlying mechanism.

METHOD

Characteristics of exosomes were verified by transmission electron microscope (TEM), nanoparticle tracking analysis, and Western blot assay. Exosome uptake for the normal human lung fibroblasts (NHLF) was assessed using a PKH67 staining assay. MTT and colony formation assays were applied to examine the proliferation abilities of NHLF. The interaction between miR-132-3p and sprouty1 (SPRY1) was confirmed by a luciferase reporter assay.

RESULTS

Lung cancer-derived exosomes promoted normal human lung fibroblast activation. Exosome inhibitor GW4869 reversed the effects of Exo on NHLF. Subsequently, miR-132-3p in lung cancer-derived exosomes activated the normal human lung fibroblast and promoted interstitial lung disease development ex vivo. Next, SPRY1 was verified to be the binding protein of miR-132-3p, and sh-SPRY1 abrogated the effects of the miR-132-3p inhibitor on NHLF.

CONCLUSION

Exosomal miR-132-3p from A549 cells accelerated the development of interstitial lung disease through binding to SPRY1, which might serve as an important target for ILDs.

Role of the Renin Angiotensin Aldosterone System in the Pathogenesis of Sepsis-Induced Acute Kidney Injury: A Systematic Review

BACKGROUND

Sepsis is a life-threatening condition responsible for up to 20% of all global deaths. Kidneys are among the most common organs implicated, yet the pathogenesis of sepsis-induced acute kidney injury (S-AKI) is not completely understood, resulting in the treatment being nonspecific and responsive. In situations of stress, the renin angiotensin aldosterone system (RAAS) may play a role. This systematic review focuses on analyzing the impact of the RAAS on the development of S-AKI and discussing the use of RAAS antagonists as an emerging therapeutic option to minimize complications of sepsis.

METHODS

Studies were identified using electronic databases (Medline via PubMed, Google Scholar) published within the past decade, comprised from 2014 to 2023. The search strategy was conducted using the following keywords: sepsis, S-AKI, RAAS, Angiotensin II, and RAAS inhibitors. Studies on human and animal subjects were included if relevant to the keywords.

RESULTS

Our search identified 22 eligible references pertaining to the inclusion criteria. Treatment of sepsis with RAAS inhibitor medications is observed to decrease rates of S-AKI, reduce the severity of S-AKI, and offer an improved prognosis for septic patients.

CONCLUSION

The use of RAAS antagonists as a treatment after the onset of sepsis has promising findings, with evidence of decreased renal tissue damage and rates of S-AKI and improved survival outcomes.

REGISTRATION

INPLASY202360098.

Damage Effects of Bisphenol A against Sepsis Induced Acute Lung Injury

In addition to oxidative damage, sepsis can cause multiple organ dysfunction and poses a life-threatening threat. In addition to severe tissue damage, hypotension, and multiple organ failure, sepsis can cause high morbidity and mortality. It is the lungs that are most vulnerable in abdominal sepsis, with impaired oxygen and nutrient exchange occurring in the pulmonary microcirculation. However, the etiology of sepsis and the link between sepsis and lung injury has not been elucidated. In this work, by exploring the data from the GEO and CTD database, a gene association study was conducted to determine whether sepsis-induced lung injury is caused by BPA. Further analysis demonstrated that MMP9, CEBPA, CYP1B1, CTSD, FKBP5, DGAT2, HP, TIMP2, ARG1 and MGST1 may play an important role in sepsis-induced lung injury. Finally, the single-cell RNA sequence demonstrated that CEBPA is mainly enriched in lung epithelial cells and epithelial cells, whereas CYP1B1 is closely related to basal cells, macrophages, and interstitial cells. In order to maintain lung function, epithelial and alveolar macrophages as well as other lung cells are important. When the lung epithelium is activated for a prolonged period of time, barrier function may be compromised and tissue damage may result, aggravating the lung injury. By using the animal model, we successfully simulated the model of sepsis lung injury. The HE staining demonstrated the rats with BPA-treated septic lung injury showed more alveolar structure to be disordered, pulmonary interstitial edema to be evident, and red blood cells as well as inflammatory cells. For PCR assay, the results demonstrated that the expression level of CEBPA is higher in the lung samples with sepsis compared with the normal samples of the lung. In order to evaluate the expression level of CEBPA and CYP1B1 in lung tissue, we then performed the PCR assay. For CYP1B1, the results demonstrated that the expression level of CYP1B1 in lung samples with sepsis is lower than in normal lung samples. In total, BPA may be a potential contributing factor to sepsis-induced lung injury.

MiR-874-5p targets VDR/NLRP3 to reduce intestinal pyroptosis and improve intestinal barrier damage in sepsis

BACKGROUND

Vitamin D receptor (VDR) is associated with intestinal barrier damage in sepsis. However, the mechanism of action of miR-874-5p/VDR/NLRP3 axis in disease has not been clearly explained. Therefore, the main content of this study is to explore the mechanism of this axis in intestinal barrier damage in sepsis.

METHODS

In order to confirm the progress of miR-874-5p regulation of VDR/NLRP3 pathway and its involvement in intestinal barrier damage in sepsis, a series of molecular biology and cell biology methods were carried out in this study. These include the establishment of cecal ligation puncture model, Western blot, RT-qPCR, hematoxylin and eosin staining, double luciferase reporting method, Fluorescence in situ hybridization, immunohistochemistry, and enzyme-linked immunosorption assay.

RESULTS

The expression level of miR-874-5p was higher and that of VDR was lower in sepsis. miR-874-5p was negatively correlated with VDR. Inhibition of miR-874-5p expression increased the expression of VDR, decreased the expression of NLRP3, reduced caspase-1 activation and IL-1β secretion, reduced pyroptosis and inflammatory response, and thus protected the intestinal barrier damage in sepsis, all of which were reversed by the downregulation of VDR.

CONCLUSIONS

This study suggested that down-regulation of miR-874-5p or up-regulation of VDR could reduce intestinal barrier damage in sepsis, which may provide potential biomarkers and therapeutic targets for intestinal barrier damage in sepsis.

Whole transcriptome sequencing analysis of blood plasma-derived exosomes from immune-related hearing loss

BACKGROUND

Early diagnosis of immune-related hearing loss and timely treatment can prevent structural damage to the inner ear and contribute to hearing retention. Exosomal miRNAs, lncRNAs and proteins have great prospects as novel biomarkers for clinical diagnosis. Our study aimed to investigate the molecular mechanisms of exosomes or exosomal ceRNA regulatory networks in immune-related hearing loss.

METHODS

An immune-related hearing loss mice model was constructed by injection with inner ear antigen, and then the blood plasma samples of the mice were collected for exosomes isolation by ultra-centrifugation. Subsequently, the different exosomes were sent for whole transcriptome sequencing using Illumina platform. Finally, a ceRNA pair was chosen for validation by RT-qPCR and dual luciferase reporter gene assay.

RESULTS

The exosomes were successfully extracted from the blood samples of the control and the immune-related hearing loss mice. After sequencing, 94 differentially expressed (DE) lncRNAs, 612 DEmRNAs, and 100 DEmiRNAs were found in the immune-related hearing loss-associated exosomes. Afterwards, ceRNA regulatory networks consisting of 74 lncRNAs, 28 miRNAs and 256 mRNAs were proposed, and the genes in the ceRNA regulatory networks were significantly enriched in 34 GO terms of biological processes and 9 KEGG pathways. Finally, Gm9866 and Dusp7 were significantly up-regulated, while miR-185-5p level was declined in the exosomes from immune-related hearing loss, and Gm9866, miR-185-5p and Dusp7 interacted with each other.

CONCLUSIONS

Gm9866-miR-185-5p-Dusp7 was confirmed to be closely correlated with the occurrence and progression of immune-related hearing loss.

A simple and accurate method to quantify real-time contraction of vascular smooth muscle cell in vitro

Vascular smooth muscle cells (VSMCs) constitute the medial layer of the blood vessel wall. Their contractile state regulates blood flow in physiological and pathological conditions. Current methods for assessing the contractility of VSMCs are not amenable to the high-throughput screening of pharmaceutical compounds. This study aimed to develop a method to address this shortcoming in the field. Real-time contraction was visualized in living VSMCs using the exogenous expression of green fluorescent protein (GFP). Image-Pro Plus software (IPPS) was used to measure various morphological cell indices. In phenylephrine-treated VSMCs, GFP fluorescence imaging was more accurate than brightfield imaging or phalloidin staining in representing VSMC morphology, as measured using IPPS. Among the multiple indices of VSMC shape, area and mean-diameter were more sensitive than length in reflecting the morphological changes in VSMC. We developed a new index, compound length, by combining the mean-diameter and length to differentiate contracted and uncontracted VSMCs. Based on the compound length, we further generated a contraction index to define a single-VSMC contractile status as single-VSMC contraction-index (SVCI). Finally, compound length and SVCI were validated to effectively assess cell contraction in VSMCs challenged with U46619 and KCl. In conclusion, GFP-based indices of compound length and SVCI can accurately quantify the real-time contraction of VSMCs. In future, the new method will be applied to high-throughput drug screening or basic cardiovascular research.

Silencing circPalm2 inhibits sepsis-induced acute lung injury by sponging miR-376b-3p and targeting MAP3K1

The apoptosis and inflammation of pulmonary epithelial cells are important pathogenic factors of sepsis-induced acute lung injury (ALI). Upregulation of circPalm2 (circ_0001212) expression levels has been previously detected in the lung tissue of ALI rats. Herein, the biological significance and detailed mechanism of circPalm2 in ALI pathogenesis were investigated. In vivo models of sepsis-induced ALI were established by treating C57BL/6 mice with cecal ligation and puncture (CLP) surgery. Murine pulmonary epithelial cells (MLE-12 cells) were stimulated with lipopolysaccharide (LPS) to establish in vitro septic ALI models. MLE-12 cell viability and apoptosis were evaluated by CCK-8 assay and flow cytometry analysis, respectively. The pathological alterations of the lung tissue were analysed based on hematoxylin-eosin (H&E) staining. Cell apoptosis in the lung tissue samples was examined by TUNEL staining assay. LPS administration suppressed the viability and accelerated the inflammation and apoptotic behaviours of MLE-12 cells. CircPalm2 displayed high expression in LPS-stimulated MLE-12 cells and possessed circular characteristics. The silencing of circPalm2 impeded apoptosis and inflammation in LPS-stimulated MLE-12 cells. Mechanistically, circPalm2 bound with miR-376b-3p, which targeted MAP3K1. In rescue assays, MAP3K1 enhancement reversed the repressive effects of circPalm2 depletion on LPS-triggered inflammatory injury and MLE-12 cell apoptosis. Furthermore, the lung tissue collected from CLP model mice displayed low miR-376b-3p expression and high levels of circPalm2 and MAP3K1. CircPalm2 positively regulated MAP3K1 expression by downregulating miR-376b-3p in murine lung tissues. Importantly, circPalm2 knockdown attenuated CLP-induced inflammation, apoptosis, and pathological alterations in lung tissues collected from mice. Silenced circPalm2 inhibits LPS-induced pulmonary epithelial cell dysfunction and mitigates abnormalities in lung tissues collected from CLP-stimulated mice via the miR-376b-3p/MAP3K1 axis in septic ALI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-022-00169-7.

Role of stem cell derivatives in inflammatory diseases

Mesenchymal stem cells (MSCs) are pluripotent stem cells of mesodermal origin with the ability of self-renewal and multidirectional differentiation, which have all the common characteristics of stem cells and the ability to differentiate into adipocytes, osteoblasts, neuron-like cells and other cells. Stem cell derivatives are extracellular vesicles(EVs) released from mesenchymal stem cells that are involved in the process of body’s immune response, antigen presentation, cell differentiation, and anti-inflammatory. EVs are further divided into ectosomes and exosomes are widely used in degenerative diseases, cancer, and inflammatory diseases due to their parental cell characteristics. However, most diseases are closely related to inflammation, and exosomes can mitigate the damage caused by inflammation in terms of suppressing the inflammatory response, anti-apoptosis and promoting tissue repair. Stem cell-derived exosomes have become an emerging modality for cell-free therapy because of their high safety and ease of preservation and transportation through intercellular communication. In this review, we highlight the characteristics and functions of MSCs-derived exosomes and discuss the regulatory mechanisms of MSCs-derived exosomes in inflammatory diseases and their potential applications in clinical diagnosis and therapy.

THE ROLES OF EXTRACELLULAR VESICLES IN SEPSIS AND SYSTEMIC INFLAMMATORY RESPONSE SYNDROME

ABSTRACT

Sepsis is a life-threatening organ dysfunction, caused by dysregulation of the host response to infection. To understand the underlying mechanisms of sepsis, the vast spectrum of extracellular vesicles (EVs) is gaining importance in this research field. A connection between EVs and sepsis was shown in 1998 in an endotoxemia pig model. Since then, the number of studies describing EVs as markers and mediators of sepsis increased steadily. Extracellular vesicles in sepsis could be friends and foes at the same time depending on their origin and cargo. On the one hand, transfer of EVs or outer membrane vesicles can induce sepsis or systemic inflammatory response syndrome with comparable efficiency as well-established methods, such as cecal ligation puncture or lipopolysaccharide injection. On the other hand, EVs could provide certain therapeutic effects, mediated via reduction of reactive oxygen species, inflammatory cytokines and chemokines, influence on macrophage polarization and apoptosis, as well as increase of anti-inflammatory cytokines. Moreover, EVs could be helpful in the diagnosis of sepsis. Extracellular vesicles of different cellular origin, such as leucocytes, macrophages, platelets, and granulocytes, have been suggested as potential sepsis biomarkers. They ensure the diagnosis of sepsis earlier than classical clinical inflammation markers, such as C-reactive protein, leucocytes, or IL-6. This review summarizes the three roles of EVs in sepsis-mediator/inducer, biomarker, and therapeutic tool.

Microscopic polyangiitis plasma-derived exosomal miR-1287-5p induces endothelial inflammatory injury and neutrophil adhesion by targeting CBL

Background

An inflammatory environment around the vessel wall caused by leukocyte infiltration is one of the characteristic histopathological features of microscopic polyangiitis (MPA); however, the pathogenic mechanisms are not fully understood. Studies have found that circulating microRNA (miRNA) can be used as potential biomarkers for the diagnosis and classification of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV), and the E3 ubiquitin ligase casitas B-lineage lymphoma (CBL) seems to be associated with inflammation. In addition, evidence indicates that miRNA can be tracked into exosomes and transferred into recipient cells to mediate the process of vascular endothelial injury. Herein, we aimed to identify the profiles of exosomal miRNA, and determine the effect of exosomal miR-1287-5p and its target gene CBL on vascular endothelial cells in MPA.

Method

We isolated plasma exosomes from patients with MPA (MPA-exo) and healthy controls (HC-exo) by ultracentrifugation and conducted exosome small-RNA sequencing to screen differential miRNA expression in MPA-exo (n = 3) compared to HC-exo (n = 3). We measured the expression levels of miR-1303, miR-1287-5p, and miR-129-1-3p using quantitative reverse transcription-polymerase chain reaction (qRT-PCR, n = 6) and performed dual luciferase reporter gene assays to confirm the downstream target gene of miR-1287-5p. In addition, we treated human umbilical vein endothelial cell (HUVEC) with MPA-exo, or transfected them with miR-1287-5p mimic/inhibitor or with CBL-siRNA/CBL-siRNA+ miR-1287-5p inhibitor. After cell culture, we evaluated the effects on vascular endothelial cells by examining the mRNA levels of IL-6, IL-8, MCP-1, ICAM-1 and E-selectin using qRT-PCR and performed neutrophil adhesion assay with haematoxylin staining.

Result

Transmission electron microscopy, Western blot and nanoparticle tracking analysis showed that we successfully purified exosomes and MPA-exo could be absorbed into HUVEC. We screened a total of 1,077 miRNA by sequencing and observed a high abundance of miR-1287-5p in the exosomes obtained from MPA plasma. The dual luciferase reporter assay identified CBL as a downstream target gene of miR-1287-5p, and the results revealed that MPA-exo decreased CBL protein expression in HUVEC. In addition, treatment with MPA-exo, up-regulating miR-1287-5p or silencing of CBL in HUVEC significantly increased the mRNA expression of inflammatory factors (including IL-6, IL-8, and MCP-1) and adhesion molecules (including ICAM-1 and E-selection) and promoted the adhesion of neutrophils to HUVEC. However, down-regulating miR-1287-5p had the opposite effect.

Conclusion

Our study revealed that MPA-exo was involved in the intercellular transfer of miR-1287-5p and subsequently promote the development of acute endothelial injury in MPA. MiR-1287-5p and CBL agonists may be promising therapeutic approach for MPA-induced vascular inflammatory injury.

Association of Genetic Polymorphisms and Serum Levels of miR-1-3p with Postoperative Mortality following Abdominal Aortic Aneurysm Repair

BACKGROUND

Several miRNAs have been implicated in the clinical outcomes of cardiovascular disorders, but the role of miR-1-3p in abdominal aortic aneurysm (AAA) prognosis remains unclear. This study aimed to investigate the correlation of single nucleotide polymorphisms (SNPs) in pri-miR-1-3p and mature miR-1-3p expression with postoperative mortality of AAA patients.

METHODS

A total of 230 AAA patients who received AAA repair were recruited and followed up for 5 years. SNP genotyping was carried out using KASP method and relative expression of serum miR-1-3p was measured with qRT-PCR.

RESULTS

Multivariate Cox regression analyses showed that both rs2155975 and rs4591246 variant genotypes were associated with increased all-cause mortality of postoperative AAA patients after adjusting possible confounders. Patients who died tended to have lower baseline miR-1-3p expression (overall and for age < 65 years, aneurysm-related death or cardiac death subgroup) when compared to alive patients; further Cox regression yielded an independent relationship of preoperative low serum miR-1-3p levels with incidents of all-cause death. Patients carrying rs2155975 AG + GG or rs4591246 AG + AA genotype had a higher ratio of low miR-1-3p levels in contrast to those with AA or GG genotype, respectively. The Kaplan-Meier survival curves suggested that the combined genotype in rs2155975 or rs4591246 and low miR-1-3p levels could decrease the overall survival of AAA patients during 5-year follow-up.

CONCLUSIONS

This pilot study demonstrated the importance of rs2155975 and rs4591246 polymorphisms and baseline serum miR-1-3p levels as promising markers to predict mortality among patients following AAA repair.

Remifentanil modulates the TLR4‑mediated MMP‑9/TIMP1 balance and NF‑κB/STAT3 signaling in LPS‑induced A549 cells

Remifentanil is a widely used in general anesthetic that has been found to suppress the inflammatory response in aortic endothelial cells. Therefore, it was hypothesized that remifentanil can inhibit inflammatory dysfunction in lung epithelial cells to alleviate acute lung injury (ALI). The present study aimed to examine the effects of remifentanil on inflammatory injury, MMP-9/tissue inhibitor of metalloproteinase 1 (TIMP1) balance and the potential associated regulatory pathways in A549 cells. Lipopolysaccharide (LPS) was used to treat A549 cells to establish ALI models. The possible roles of different concentrations of remifentanil in cell viability was then determined by CCK-8 and Lactate dehydrogenase release assay. Apoptosis was assessed by flow cytometry analysis and western blotting. Inflammation and oxidative stress were measured by ELISA and corresponding kits respectively. Subsequently, the effects of remifentanil on Toll-like receptor 4 (TLR4) expression and the MMP-9/TIMP1 balance were assessed by western blotting and ELISA. In addition, the effects of remifentanil on NF-κB/STAT3 signaling were evaluated by measuring the protein expression levels of associated pathway components and the degree of NF-κB nuclear translocation using western blotting and immunofluorescence respectively. Remifentanil was found to increase cell viability whilst reducing apoptosis, inflammation and oxidative stress in the LPS-treated cells. In addition, TLR4 inhibitor CLI-095 suppressed MMP-9 expression and secretion while potentiating TIMP1 expression and secretion in LPS-challenged cells. Remifentanil treatment was able to modulate TLR4 to mediate LPS-induced MMP-9/TIMP1 imbalance and suppress the phosphorylation of NF-κB/STAT3 signaling components, in addition to inhibiting NF-κB nuclear translocation. Taken together, remifentanil downregulated TLR4 to reduce MMP-9/TIMP1 imbalance to inhibit inflammatory dysfunction in LPS-treated A549 cells, by regulating NF-κB/STAT3 signaling.

Extracellular vesicles participate in the pathogenesis of sepsis

Sepsis is one of the leading causes of mortality worldwide and is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. The early diagnosis and effective treatment of sepsis still face challenges due to its rapid progression, dynamic changes, and strong heterogeneity among different individuals. To develop novel strategies to control sepsis, a better understanding of the complex mechanisms of sepsis is vital. Extracellular vesicles (EVs) are membrane vesicles released from cells through different mechanisms. In the disease state, the number of EVs produced by activated or apoptotic cells and the cargoes they carry were altered. They regulated the function of local or distant host cells in autocrine or paracrine ways. Current studies have found that EVs are involved in the occurrence and development of sepsis through multiple pathways. In this review, we focus on changes in the cargoes of EVs in sepsis, the regulatory roles of EVs derived from host cells and bacteria, and how EVs are involved in multiple pathological processes and organ dysfunction in sepsis. Overall, EVs have great application prospects in sepsis, such as early diagnosis of sepsis, dynamic monitoring of disease, precise therapeutic targets, and prevention of sepsis as a vaccine platform.

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.

Disrupted metabolic and spontaneous neuronal activity of hippocampus in sepsis associated encephalopathy rats: A study combining magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging

Background

The diagnosis of sepsis associated encephalopathy (SAE) remains challenging in clinical settings because of a lack of specific biomarkers. Functional magnetic resonance imaging (fMRI) and proton magnetic resonance spectroscopy (1H-MRS) can be used to aid in the diagnosis of cognition related diseases. This study investigated changes in functional activities and brain metabolites in the hippocampus in SAE rats by fMRI and 1H-MRS.

Materials and methods

Sepsis associated encephalopathy rats underwent cecal ligation and perforation (CLP) surgery. The Morris water maze (MWM) test was then used to evaluate cognitive function. Resting state-fMRI and 1H-MRS scanning were performed 7 and 14 days after CLP surgery to reveal spontaneous neuronal activity and metabolite changes in the hippocampus. The amplitude of low-frequency fluctuation (ALFF) was used to evaluate spontaneous neuronal activity in the hippocampus. Creatine (Cr), Myo-inositol (mI), and glutamine/glutamate (Glx) levels were measured with 1H-MRS scanning. Immunofluorescence and levels of interleukin (IL)-1β, interleukin (IL)-6, and C-reactive protein (CRP) in the hippocampus were additionally detected to evaluate microglial mediated inflammatory responses. Statistical analysis was performed to evaluate correlations between hippocampal metabolism and behavioral findings.

Results

Cecal ligation and perforation treated rats exhibited impaired learning and memory function in the MWM test at days 7 and 14. Elevation of IL-1β in the hippocampus, as well as immunofluorescence results, confirmed severe neuro inflammation in the hippocampus in SAE rats. Compared with the sham group, the ALFF of the right CA-1 area of the hippocampus was higher at day 7after CLP surgery. The Glx/Cr and mI/Cr ratios were enhanced at day 7 after CLP surgery and slightly lower at day 14 after CLP surgery. The ALFF value, and Glx/Cr and mI/Cr ratios were negatively correlated with time spent in the target quadrant in the MWM test.

Conclusion

Spontaneous neuronal activity and metabolites showed significant alterations in SAE rats. The elevated ALFF value, Glx/Cr ratio, and mI/Cr ratio in the hippocampus were positively associated with cognitive deficits. Changes in ALFF and metabolites in hippocampus may serve as potential neuroimaging biomarkers of cognitive disorders in patients with SAE.

Correlation of serum miR-127 level with severity and prognosis of sepsis

OBJECTIVE

To investigate the relationship of serum miR-127 level with the severity of sepsis patients and its predictive efficacy for prognosis.

METHODS

A total of 205 healthy individuals who underwent physical examination in Jingzhou Hospital Affiliated to Yangtze University and 205 patients with sepsis who were hospitalized in ICU from January 2021 to March 2022 were recruited in this study, and their serum miR-127 level were measured. The patients were divided into a high-miR-127 group (110 cases) and a low-miR-127 group (95 cases) based on the optimal cut-off value of miR-127 to assess the prognosis. The clinical data and 28-day survival of the two groups were analyzed. The patients were further divided into a death group (57 cases) and a survival group (148 cases) based on their 28-day survival. Factors associated with poor prognosis of sepsis were analyzed by Cox regression.

RESULTS

There were statistically significant differences in heart rate, body temperature, white blood cells (WBC), hemoglobin (Hb), procalcitonin (PCT), C-reactive protein (CRP), alanine aminotransferase (ALT), total bilirubin (TBIL), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), cardiac troponin I (cTnI), blood urea nitrogen (BUN), Prothrombin time (PT), serum creatinine (Scr), fibrinogen (FIB) and miR-127 between sepsis patients and healthy controls (P < 0.05). Compared to those in the low-miR-127 group, PCT, BUN, and SOFA scores in the high-miR-127 group were significantly higher (P < 0.05). The 28-day cumulative survival was lower in the high-miR-127 group (58.20%) than that in the low-miR-127 group (88.40%) (Log Rank χ² =25.598, P < 0.05). Those with high miR-127 still had a higher risk of poor prognosis compared to those with low miR-127 after correcting for SOFA score, APACHE II score and PCT (HR=3.292, 95% CI: 1.663-6.517, P < 0.05). The areas under the ROC curve (AUC) of serum miR-127, SOFA score, and APACHE II score for predicting prognosis of sepsis patients were 0.748 (0.674-0.823), 0.810 (0.742-0.878) and 0.864 (0.811-0.916), respectively.

CONCLUSION

Serum miR-127 is highly expressed in sepsis and related to the severity of sepsis. Those with high miR-127 level have a higher risk of poor prognosis.

Integrating bulk and single-cell sequencing reveals the phenotype-associated cell subpopulations in sepsis-induced acute lung injury

The dysfunctional immune response and multiple organ injury in sepsis is a recurrent theme impacting prognosis and mortality, while the lung is the first organ invaded by sepsis. To systematically elucidate the transcriptomic changes in the main constituent cells of sepsis-injured lung tissue, we applied single-cell RNA sequencing to the lung tissue samples from septic and control mice and created a comprehensive cellular landscape with 25044 cells, including 11317 immune and 13727 non-immune cells. Sepsis alters the composition of all cellular compartments, particularly neutrophils, monocytes, T cells, endothelial, and fibroblasts populations. Our study firstly provides a single-cell view of cellular changes in septic lung injury. Furthermore, by integrating bulk sequencing data and single-cell data with the Scissors-method, we identified the cell subpopulations that are most associated with septic lung injury phenotype. The phenotypic-related cell subpopulations identified by Scissors-method were consistent with the cell subpopulations with significant composition changes. The function analysis of the differentially expressed genes (DEGs) and the cell-cell interaction analysis further reveal the important role of these phenotype-related subpopulations in septic lung injury. Our research provides a rich resource for understanding cellular changes and provides insights into the contributions of specific cell types to the biological processes that take place during sepsis-induced lung injury.

REGULATORY ROLE OF NONCODING RNA IN SEPSIS AND SEPSIS-ASSOCIATED ORGAN DYSFUNCTION: AN UPDATED SYSTEMATIC REVIEW

ABSTRACT

Background: The exact molecular mechanisms underlying sepsis remain unclear. Accumulating evidence has shown that noncoding RNAs (ncRNAs) are involved in sepsis and sepsis-associated organ dysfunction (SAOD). Methods: We performed this updated systematic review focusing mainly on research conducted in the last 5 years regarding ncRNAs associated with sepsis and SAOD. The following medical subject headings were used in the PubMed database from October 1, 2016, to March 31, 2022: "microRNA," "long noncoding RNA," "circular RNA," "sepsis," and/or "septic shock." Studies investigating the role of ncRNAs in the pathogenesis of sepsis and as biomarkers or therapeutic targets in the disease were included. Data were extracted in terms of the role of ncRNAs in the pathogenesis of sepsis and their applicability for use as biomarkers or therapeutic targets in sepsis. The quality of the studies was assessed using a modified guideline from the Systematic Review Center for Laboratory Animal Experimentation. Results: A total of 537 original studies investigated the potential roles of ncRNAs in sepsis and SAOD. Experimental studies in the last 5 years confirmed that long ncRNAs have important regulatory roles in sepsis and SAOD. However, studies on circular RNAs and sepsis remain limited, and more studies should be conducted to elucidate this relationship. Among the included studies, the Systematic Review Center for Laboratory Animal Experimentation scores ranged from 3 to 7 (an average score of 3.78). Notably, 94 ncRNAs were evaluated as potential biomarkers for sepsis, and selective reporting of the sensitivity, specificity, and receiver operating characteristic curve was common. A total of 117 studies demonstrated the use of ncRNAs as potential therapeutic targets in sepsis and SAOD. At a molecular level, inflammation-related pathways, mitochondrial dysfunction, cell apoptosis, and/or oxidative stress were the most extensively studied. Conclusion: This review suggests that ncRNAs could be good biomarkers and therapeutic candidates for sepsis and SAOD. Prospective, large-scale, and multicenter cohort studies should be performed to evaluate specific ncRNAs as biomarkers and test the organ-specific delivery of these regulatory molecules when used as therapeutic targets.

Extracellular vesicles in the pathogenesis and treatment of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common life-threatening lung diseases associated with acute and severe inflammation. Both have high mortality rates, and despite decades of research on clinical ALI/ARDS, there are no effective therapeutic strategies. Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury. Recently, studies on the role of extracellular vesicles (EVs) in regulating normal and pathophysiologic cell activities, including inflammation and injury responses, have attracted attention. Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes, which can be used to diagnose and predict the development of ALI/ARDS. EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function, and thereby promote cell proliferation and tissue regeneration. This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation, particularly ALI/ARDS.

LYTIC COCKTAIL ATTENUATES CATECHOLAMINE SURGE AFTER SEVERE BURNS BY BLOCKING HISTAMINE H1 RECEPTOR/PKA/CREB/TYROSINE HYDROXYLASE SIGNALING IN CHROMAFFIN CELLS

ABSTRACT

Severe burns develop a catecholamine surge, inducing severe damage to the organism, raising the possibility of multisystem organ failure, and even death. The mechanisms of catecholamine surge have not been fully elucidated, and few strategies are generally acceptable to reduce catecholamine surge postburn. Thus, it is valuable to investigate the underlying mechanisms of catecholamine surge postburn to develop targeted interventions to attenuate it. We have found that the lytic cocktail alleviates the surge of catecholamine and organ injury after severe burn; however, the underlying mechanisms were still unclear. Moreover, the lytic cocktail has side effects, such as significant arterial hypotension and breathing depression, limiting its clinical application. This study aims to investigate the therapeutic mechanism of the lytic cocktail in regulating catecholamine levels postburn. We find that promethazine, a classic histamine H1 receptor blocker and a component of the lytic cocktail, can effectively reduce catecholamine surge and organ injury postburn. Our study confirms that blood histamine levels increase after severe burns. We find that histamine can amplify the catecholamine surge by elevating tyrosine hydroxylase expression and catecholamine synthesis in chromaffin cells through the histamine H1 receptor/Protein Kinase A /cAMP-response element binding protein signaling pathway. In summary, for the first time, we find that histamine plays a vital role in catecholamine surge postburn. We also confirm that the lytic cocktail effectively alleviates catecholamine surge and organ injury postburn through promethazine.

Long intergenic noncoding RNA LINC01287 drives the progression of cervical cancer via regulating miR-513a-5p/SERP1

Cervical cancer is one of the most frequent types of cancer in women, which is characterized by high invasion and metastatic tendency in its advanced stage. Emerging evidence indicated that long non-coding RNAs (LncRNAs) are involved in the pathogenesis of cervical cancer. LINC01287 has been reported to play crucial regulatory roles in the pathogenesis and progression of multiple cancers. However, up until now, whether LINC01287 is associated with the initiation and development of cervical cancer remains largely unknown. In the present study, expression levels of LINC01287, miR-513a-5p and stress-associated endoplasmic reticulum protein 1 (SERP1) mRNA were quantified utilizing qRT-PCR. A series of functional experiments including CCK-8 assay, colony formation assay, transwell assay, flow cytometry, and tumor xenograft growth of cervical cancer cells were performed for studying the effects of LINC01287. The luciferase reporter assay, pull-down assay, and western blot were used to confirm the downstream targets of LINC01287 and miR-513a-5p. The results demonstrate that LINC01287 was highly expressed in cervical cancer tissue samples and cell lines. High LINC01287 predicts a poor prognosis for cervical cancer patients. Additional gain- and loss-of-function experiments demonstrated that silencing LINC01287 inhibited cervical cancer cells proliferation, colony formation, migration, apoptosis in vitro and retarded tumor growth and metastasis in vivo. Furthermore, the dual-luciferase reporter gene system and RNA pulldown assay validated that LINC01287 positively regulated SERP1 expressions by sponging miR-513a-5p, and LINC01287 inhibited cervical cancer progression by regulating miR-513a-5p/SERP1 axis. In conclusion, the current study first identified that LINC01287/miR-513a-5p/SERP1 axis played an important role in cervical cancer progression. LINC01287 might be a prognostic biomarker and a target for new therapies in patients with cervical cancer.

Differential expression profile of plasma exosomal microRNAs in acute type A aortic dissection with acute lung injury

MicroRNAs (miRNAs) packaged into exosomes mediate cell communication and contribute to the pathogenesis of acute type A aortic dissection (ATAAD) with acute lung injury (ALI). The expression profile of plasma exosomal miRNAs in ATAAD patients with ALI hasn’t been identified. We performed a miRNA-sequencing to analyze the differentially expressed miRNAs (DE-miRNAs) of circulating exosomes in ATAAD patients with ALI compared to patients without ALI, founding 283 specific miRNAs in two groups. We respectively selected the top 10 downregulated and upregulated DE-miRNAs for further studies. The predicted transcription factors (TFs) of these DE-miRNAs were SMAD2, SRSF1, USF1, etc. The Gene Ontology (GO) and Kyoto Encyclopedia Genes and Genomes (KEGG) analysis predicted their target genes mainly involved acute inflammatory response, cell junction, cytoskeleton, NF-κB signaling pathway, etc. Construction and analysis of the PPI network revealed that RHOA and INSR were considered hub genes with the highest connectivity degrees. Moreover, we confirmed two exosomal miRNAs (hsa-miR-485-5p and hsa-miR-206) by real-time quantitative polymerase chain reaction (RT-qPCR) in a validation cohort. Our study identified a plasma exosomal miRNAs signature related to ATAAD with ALI. Certain DE-miRNAs may contribute to the progression of this disease, which help us better understand the pathogenesis of ATAAD with ALI.

The Extracellular MicroRNAs on Inflammation: A Literature Review of Rodent Studies

Inflammation is an indispensable biological process stimulated by infection and injuries. Inflammatory mechanisms related to extracellular vesicles (EVs), which are small membrane structures carrying various molecules, were summarized in this review. Emerging evidence from animal studies has highlighted the role of EVs in modulating inflammatory responses, by transporting various molecules involved in host defense. In this review, we have discussed the role of EV miRNAs in inflammation. Rodent studies associated with extracellular miRNAs in inflammatory diseases, published from 2012 to 2022, were explored from PUBMED, EMBASE, and MEDLINE. A total of 95 studies were reviewed. In summary, EV-associated miRNAs play a key role in various diseases, including organ injury, immune dysfunction, neurological disease, metabolic syndrome, vesicular disease, arthritis, cancer, and other inflammatory diseases. Diverse EV-associated miRNAs regulate inflammasome activation and pro- and anti-inflammatory cytokine levels by targeting genes.

Macrophage-derived exosomal aminopeptidase N aggravates sepsis-induced acute lung injury by regulating necroptosis of lung epithelial cell

Sepsis-induced acute lung injury (ALI) is a serious sepsis complication and the prevailing cause of death. Circulating plasma exosomes might exert a key role in regulating intercellular communication between immunological and structural cells, as well as contributing to sepsis-related organ damage. However, the molecular mechanisms by which exosome-mediated intercellular signaling exacerbate ALI in septic infection remains undefined. Therefore, we investigated the effect of macrophage-derived exosomal APN/CD13 on the induction of epithelial cell necrosis. Exosomal APN/CD13 levels in the plasma of septic mice and patients with septic ALI were found to be higher. Furthermore, increased plasma exosomal APN/CD13 levels were associated with the severity of ALI and fatality in sepsis patients. We found remarkably high expression of APN/CD13 in exosomes secreted by LPS-stimulated macrophages. Moreover, c-Myc directly induced APN/CD13 expression and was packed into exosomes. Finally, exosomal APN/CD13 from macrophages regulated necroptosis of lung epithelial cells by binding to the cell surface receptor TLR4 to induce ROS generation, mitochondrial dysfunction and NF-κB activation. These results demonstrate that macrophage-secreted exosomal APN/CD13 can trigger epithelial cell necroptosis in an APN/CD13-dependent manner, which provides insight into the mechanism of epithelial cell functional disorder in sepsis-induced ALI.

Necroptosis of lung epithelial cells is regulated by aminopeptidase N levels in circulating plasma exosomes in patients and mice with sepsis-induced acute lung injury.

SERP1 reduces inchoate acute hepatic injury through regulation of endoplasmic reticulum stress via the GSK3β/β‑catenin/TCF/LEF signaling pathway

The liver is a crucial digestive organ of humans and in charge of detoxification. Acute hepatic injury is an aggressive type of hepatic disease and its harmful effect cannot be ignored. The present study examined the role and mechanism of stress-associated endoplasmic reticulum protein 1 (SERP1) in acute hepatic injury. Mice were injected intraperitoneally with D-galactosamine/lipopolysaccharide (LPS) and rat hepatocytes were induced by LPS to establish an acute hepatic injury model. Tissue lesions were observed by H&E staining, and biomarkers of hepatic injury in the serum were examined. Western blotting, immunohistochemistry and reverse transcription-quantitative PCR were performed to assess SERP1 expression in tissues and hepatocytes. A SERP1 overexpression plasmid was constructed to evaluate the role of SERP1 in inflammation, apoptosis, endoplasmic reticulum stress (ERS) and the GSK3β/β-catenin/T-cell factor (TCF)/lymphoid enhancing factor (LEF) signaling pathway. In addition, a GSK3β overexpression plasmid was constructed to investigate the role of GSK3β/β-catenin signal activation. Additionally, the present study investigated whether SERP1 regulated the endoplasmic reticulum via this pathway. In the present study, reliable animal and cellular hepatic injury models were established and verified. SERP1 overexpression reduced the expression of inflammatory factors, apoptosis-related proteins and ERS-related proteins, as well as the expression of proteins related to GSK3β/β-catenin/TCF/LEF signaling pathways. A GSK3β overexpression plasmid was constructed and it was revealed that GSK3β overexpression could reverse the effects of SERP1 overexpression in aforementioned aspects. This suggested that the activation of the GSK3β/β-catenin/TCF/LEF signaling pathway may be required for the regulation of SERP1. In conclusion, SERP1 regulated ERS via the GSK3β/β-catenin/TCF/LEF signaling pathway, thereby reducing inchoate acute hepatic injury.

Exosomal RNAs: Novel Potential Biomarkers for Diseases-A Review

Exosomes are a subset of nano-sized extracellular vesicles originating from endosomes. Exosomes mediate cell-to-cell communication with their cargos, which includes mRNAs, miRNAs, lncRNAs, and circRNAs. Exosomal RNAs have cell specificity and reflect the conditions of their donor cells. Notably, their detection in biofluids can be used as a diagnostic marker for various diseases. Exosomal RNAs are ideal biomarkers because their surrounding membranes confer stability and they are detectable in almost all biofluids, which helps to reduce trauma and avoid invasive examinations. However, knowledge of exosomal biomarkers remains scarce. The present review summarizes the biogenesis, secretion, and uptake of exosomes, the current researches exploring exosomal mRNAs, miRNAs, lncRNAs, and circRNAs as potential biomarkers for the diagnosis of human diseases, as well as recent techniques of exosome isolation.