Upregulation of endothelial cell-derived exosomal microRNA-125b-5p protects from sepsis-induced acute lung injury by inhibiting topoisomerase II alpha

Extracellular vesicles and the lung: from disease pathogenesis to biomarkers and treatments

Nanosized extracellular vesicles (EVs) are released by all cells to convey cell-to-cell communication. EVs, including exosomes and microvesicles, carry an array of bioactive molecules, such as proteins and RNAs, encapsulated by a membrane lipid bilayer. Epithelial cells, endothelial cells, and various immune cells in the lung contribute to the pool of EVs in the lung microenvironment and carry molecules reflecting their cellular origin. EVs can maintain lung health by regulating immune responses, inducing tissue repair, and maintaining lung homeostasis. They can be detected in lung tissues and biofluids such as bronchoalveolar lavage fluid and blood, offering information about disease processes, and can function as disease biomarkers. Here, we discuss the role of EVs in lung homeostasis and pulmonary diseases such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, pulmonary fibrosis, and lung injury. The mechanistic involvement of EVs in pathogenesis and their potential as disease biomarkers are discussed. Finally, the pulmonary field benefits from EVs as clinical therapeutics in severe pulmonary inflammatory disease, as EVs from mesenchymal stem cells attenuate severe respiratory inflammation in multiple clinical trials. Further, EVs can be engineered to carry therapeutic molecules for enhanced and broadened therapeutic opportunities, such as the anti-inflammatory molecule CD24. Finally, we discuss the emerging opportunity of using different types of EVs for treating severe respiratory conditions.

MSC-derived exosomal miR-125b-5p suppressed retinal microvascular endothelial cell ferroptosis in diabetic retinopathy

Progressive endothelial cell injury of retinal vascular is a vital factor in diabetic retinopathy (DR) pathogenesis. Mesenchymal stem cells-derived small extracellular vesicles (MSC-sEVs) showed beneficial effects on DR. However, the effects of MSC-sEVs on endothelial dysfunction of DR and the mechanism is still unclear. In this study, MSC-sEVs mitigated retinal blood-retina barrier (BRB) impairment in rats with streptozotocin (STZ)-induced DR by reducing ferroptosis in vivo and in vitro. MSC-sEVs miRNA sequencing analysis revealed that miR-125b-5p may mediate human retina microvascular endothelial cells (HRMECs) ferroptosis and P53 as a downstream target based on dual-luciferase reporter assays. Silencing miR-125b-5p in MSC-sEVs reversed the therapeutic effects of MSC-sEVs on rats with DR and advanced glycation end products (AGEs)-treated HRMECs. Additionally, overexpression of miR-125b-5p could diminish ferroptosis in HRMECs, and this effect could be effectively reversed by overexpressing P53. This study indicated the potential therapeutic effect of MSC-sEVs on vascular endothelial function maintenance and that the delivery of sEVs carrying miR-125b-5p could prevent endothelial cell ferroptosis by inhibiting P53, thereby protecting the BRB.

Clinical value of dysregulated miR-125b-5p in severe pneumonia children

BACKGROUND

Severe pneumonia is an important contributor to the high mortality of sick young children. The microRNA-125b-5p (miR-125b-5p), which is widely involved in various cancers, is closely related to a variety of lung diseases. However, its role in severe pneumonia children remains to be studied.

OBJECTIVE

This study focused on the expression and clinical value of miR-125b-5p in severe pneumonia children.

MATERIALS AND METHODS

The study subjects included 96 pneumonia children and 127 severe pneumonia children. These children were aged between 2-10 years. The expression level of serum miR-125b-5p was assessed by qRT-PCR. The receiver operator characteristic (ROC) curve was employed to identify severe pneumonia children from pneumonia individuals. Kaplan-Meier curve was plotted based on follow-up results and multivariate Cox regression analysis was applied to evaluate the contribution of miR-125b-5p to poor prognostic in severe pneumonia children.

RESULTS

MiR-125b-5p was remarkedly reduced in severe pneumonia children compared to pneumonia individuals. The area under the curve (AUC) was 0.9267 and the sensitivity and specificity were 84.25% and 89.58%, respectively. The accumulative survival rate in low miR-125b-5p group showed a remarkable decrease compared to the high miR-125b-5p group (P = 0.033). Increased procalcitonin (PCT, HR: 2.631, 95% CI: 1.029-6.732, P = 0.043) and reduced miR-125b-5p (HR: 0.301, 95% CI: 0.110-0.826, P = 0.020) were found to be related to the poor prognosis in severe pneumonia children.

CONCLUSION

The reduced miR-125b-5p was an underlying diagnostic indicator of severe pneumonia and was an independent risk factor of poor prognosis in severe pneumonia children.

Study on the diagnostic role of exosome-derived miRNAs in postoperative septic shock and non-septic shock patients

BACKGROUND

Diagnosing septic shock promptly is essential but challenging, especially due to its clinical similarity to non-septic shock. Extracellular vesicle-derived miRNAs may serve as biomarkers to distinguish septic shock from non-septic shock, providing a more accurate diagnostic tool for postsurgical patients. This study aims to identify extracellular vesicle-derived miRNA signatures that differentiate septic shock from non-septic shock in postsurgical patients, potentially improving diagnostic accuracy and clinical decision-making.

METHODS

A multicentre, prospective study was conducted on miRNA profiles in shock patients. Two cohorts were recruited from the Intensive Care Units of two Spanish hospitals: a discovery cohort with 109 patients and a validation cohort with 52 patients. Plasma samples were collected within 24 h of shock diagnosis and subjected to miRNA sequencing. High-throughput sequencing data from the discovery cohort were analysed to identify differentially expressed miRNAs. These findings were validated via qPCR in the validation cohort.

RESULTS

Thirty miRNAs were identified as significantly differentially expressed between septic and non-septic shock patients. Among these, six miRNAs-miR-100-5p, miR-484, miR-10a-5p, miR-148a-3p, miR-342-3p, and miR-451a-demonstrated strong diagnostic capabilities for septic shock. A combination of miR-100-5p, miR-148a-3p, and miR-451a achieved an area under the curve of 0.894, with qPCR validation in the validation cohort yielding an area under the curve of 0.960.

CONCLUSIONS

This study highlights extracellular vesicle-derived miRNAs as promising biomarkers for differentiating septic from non-septic shock. The identified three-miRNA signature has significant potential to enhance septic shock diagnosis, thereby aiding in timely and appropriate treatment for postsurgical patients.

MiR-125b-5p ameliorates ox-LDL-induced vascular endothelial cell dysfunction by negatively regulating TNFSF4/TLR4/NF-κB signaling

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell dysfunction plays a crucial role in the progression of atherosclerosis (AS). Although miR-125b-5p is known to be involved in cardiovascular and cerebrovascular disorders, its function in ox-LDL-induced endothelial injury is still not well understood.

METHODS

An in vitro AS cell model was established by exposing human umbilical vein endothelial cells (HUVECs) to 100 µg/mL ox-LDL for 24 h. A series of functional assays, including CCK-8 assay, flow cytometry, MDA and SOD kits, capillary-like network formation assay and ELISA assay were performed in vitro. TNFSF4/TLR4/NF-κB pathway-related protein expressions were measured by Western blot. Molecular mechanisms were elucidated through quantitative real-time PCR, western blot analysis, and luciferase reporter assays.

RESULTS

Our investigation revealed that exposure to ox-LDL led to a downregulation in miR-125b-5p, while upregulating the expression of tumor necrosis factor (ligand) superfamily, member 4 (TNFSF4), TLR4, p-p65 and p-IkBa in HUVECs in a dose-dependent manner. We confirmed TNFSF4 as a direct target of miR-125b-5p. Ox-LDL exposure led to decreased cell viability and angiogenic capacity, along with increased apoptosis, inflammation, and oxidative stress in HUVECs. These effects were reversed by overexpressing miR-125b-5p or knocking down TNFSF4. Overexpression of TNFSF4 significantly reversed the effects brought about by miR-125b-5p in HUVECs exposed to ox-LDL. Moreover, miR-125b-5p inactivated the TLR4/NF-κB signaling pathway by negatively regulating TNFSF4.

CONCLUSIONS

In summary, our findings demonstrate that miR-125b-5p possessed an anti-inflammatory and anti-apoptosis against ox-LDL-induced HUVEC injury by regulating the TNFSF4/TLR4/NF-κB signaling, indicating that miR-125b-5p may have an important therapeutic function for AS.

Altered expression profile of plasma exosomal microRNAs in exclusive electronic cigarette adult users

Little is known about how exclusive e-cigarette use affects exosomal microRNA (miRNA) expression, which is crucial in inflammation and disease processes like cancer. We compared exosomal miRNA profiles between exclusive e-cigarette users and non-users. We used plasma samples from 15 exclusive e-cigarette users and 15 non-users from the Population Assessment of Tobacco and Health (PATH) Wave 1 study (2013-2014) and sequenced miRNAs with Illumina NextSeq 500/550. We performed differential analyses using DESeq2 in R/Bioconductor, adjusting for race, and conducted gene enrichment analyses on target genes regulated by significant miRNAs. Further, molecular-based techniques using the miRNA mimics and inhibitors were applied for the validation of the expressions of the miRNAs in vitro. We identified four miRNAs that were upregulated in exclusive e-cigarette users compared to non-users: hsa-miR-100-5p, hsa-miR-125a-5p, hsa-miR-125b-5p, and hsa-miR-99a-5p, after adjusting for the confounding effects of race. However, none of the miRNAs remained statistically significant after controlling for the false discovery rate (FDR) at 5%. Subgroup analysis of White participants only identified four miRNAs (hsa-miR-100-5p, hsa-miR-125b-5p, hsa-miR-200b-3p, and hsa-miR-99a-5p) that were also upregulated in e-cigarette users with one miRNA hsa-miR-200b-3p remaining statistical significance after controlling for the FDR at 5%. GO enrichment analysis showed that these miRNAs are involved in processes like transcription regulation and cellular protein modification. KEGG pathway analysis indicated their involvement in cancer pathways, including small cell lung cancer, renal cell carcinoma, and signaling pathways (neurotrophin, ErbB, PI3K-Akt, FoxO, Hippo, MAPK, TGF-beta). Overexpression of hsa-miR-125b-5p promoted DNA damage in bronchial epithelial cells. These findings suggest an elevation of carcinogenic cellular signaling pathways in exclusive e-cigarette users.

Cell-cell crosstalk in the pathogenesis of acute lung injury and acute respiratory distress syndrome

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are the result of an exaggerated inflammatory response triggered by a variety of pulmonary and systemic insults. The lung tissues are comprised of a variety of cell types, including alveolar epithelial cells, pulmonary vascular endothelial cells, macrophages, neutrophils, and others. There is mounting evidence that these diverse cell populations within the lung interact to regulate lung inflammation in response to both direct and indirect stimuli. The aim of this review is to provide a summary and discussion of recent advances in the understanding of the importance of cell-cell crosstalk in the pathogenesis of ALI/ARDS, with a specific focus on the cell-cell interactions that may offer prospective therapeutic avenues for ALI/ARDS.

Elucidating the role of Rhodiola rosea L. in sepsis-induced acute lung injury via network pharmacology: emphasis on inflammatory response, oxidative stress, and the PI3K-AKT pathway

CONTEXT

Sepsis-induced acute lung injury (ALI) is associated with high morbidity and mortality. Rhodiola rosea L. (Crassulaceae) (RR) and its extracts have shown anti-inflammatory, antioxidant, immunomodulatory, and lung-protective effects.

OBJECTIVE

This study elucidates the molecular mechanisms of RR against sepsis-induced ALI.

MATERIALS AND METHODS

The pivotal targets of RR against sepsis-induced ALI and underlying mechanisms were revealed by network pharmacology and molecular docking. Human umbilical vein endothelial cells (HUVECs) were stimulated by 1 μg/mL lipopolysaccharide for 0.5 h and treated with 6.3, 12.5, 25, 50, 100, and 200 μg/mL RR for 24 h. Then, the lipopolysaccharide-stimulated HUVECs were subjected to cell counting kit-8 (CCK-8), enzyme-linked immunosorbent, apoptosis, and Western blot analyses. C57BL/6 mice were divided into sham, model, low-dose (40 mg/kg), mid-dose (80 mg/kg), and high-dose (160 mg/kg) RR groups. The mouse model was constructed through caecal ligation and puncture, and histological, apoptosis, and Western blot analyses were performed for further validation.

RESULTS

We identified six hub targets (MPO, HRAS, PPARG, FGF2, JUN, and IL6), and the PI3K-AKT pathway was the core pathway. CCK-8 assays showed that RR promoted the viability of the lipopolysaccharide-stimulated HUVECs [median effective dose (ED50) = 18.98 μg/mL]. Furthermore, RR inhibited inflammation, oxidative stress, cell apoptosis, and PI3K-AKT activation in lipopolysaccharide-stimulated HUVECs and ALI mice, which was consistent with the network pharmacology results.

DISCUSSION AND CONCLUSION

This study provides foundational knowledge of the effective components, potential targets, and molecular mechanisms of RR against ALI, which could be critical for developing targeted therapeutic strategies for sepsis-induced ALI.

Nanolevel Immunomodulators in Sepsis: Novel Roles, Current Perspectives, and Future Directions

Sepsis represents a profound challenge in critical care, characterized by a severe systemic inflammatory response which can lead to multi-organ failure and death. The intricate pathophysiology of sepsis involves an overwhelming immune reaction that disrupts normal host defense mechanisms, necessitating innovative approaches to modulation. Nanoscale immunomodulators, with their precision targeting and controlled release capabilities, have emerged as a potent solution to recalibrate immune responses in sepsis. This review explores the recent advancements in nanotechnology for sepsis management, emphasizing the integration of nanoparticulate systems to modulate immune function and inflammatory pathways. Discussions detail the development of the immune system, the distinct inflammatory responses triggered by sepsis, and the scientific principles underpinning nanoscale immunomodulation, including specific targeting mechanisms and delivery systems. The review highlights nanoformulation designs aimed at enhancing bioavailability, stability, and therapeutic efficacy, which shows promise in clinical settings by modulating key inflammatory pathways. Ultimately, this review synthesizes the current state of knowledge and projects future directions for research, underscoring the transformative potential of nanolevel immunomodulators for sepsis treatment through innovative technologies and therapeutic strategies.

Endothelial-derived exosomes: A novel therapeutic strategy for LPS-induced myocardial damage with anisodamine

Sepsis-induced myocardial dysfunction presents significant challenges in clinical management and is associated with increased mortality. Anisodamine (654-1/-2) has potentials in alleviating cardiac and endothelial impairments associated with sepsis. Exosomes, small vesicles secreted by cells, carry various bioactive molecules, such as nucleic acids, proteins, and lipids. These vesicles can travel to target cells to influence their function and modulating biological processes. In the context of endothelial-cardiac crosstalk, exosomes derived from endothelial cells can transfer signals that either exacerbate or mitigate myocardial injury, playing a crucial role in the progression of cardiovascular diseases. However, the precise role of endothelial-cardiac crosstalk, particularly through exosomes, in mediating the cardioprotective effects of anisodamine remains unclear. This study evaluated the effects of anisodamine on myocardial and endothelial injuries induced by LPS. Mechanisms were analyzed through network pharmacology, molecular docking, Western blotting, and RT-qPCR. The interaction between endothelial and cardiomyocyte inflammatory responses to anisodamine was assessed using a co-culture assay. Furthermore, both in vivo and in vitro assays were conducted to evaluate the effects of anisodamine-/LPS- treated HUVECs exosomes on A16 cell and myocardial function in mice. Anisodamine effectively mitigated apoptosis, inflammation, mitochondrial and myocardial injury, glycocalyx degradation, and oxidative stress by regulating the PI3K-AKT, NLRP-3/Caspase-1/ASC, TNF-α/PKCα/eNOs/NO, and NF-κB/iNOs/NO pathways in A16 cells and HUVECs. Moreover, in vivo and in vitro assays confirmed the protective effects of anisodamine against myocardial injuries mediated by exosomes derived from LPS-treated HUVECs. In summary, anisodamine ameliorated inflammation-induced endothelial and cardiomyocyte dysfunction. The in vitro and in vivo assays demonstrated that anisodamine could alleviate myocardial dysfunction through exosome-mediated mechanisms, offering new therapeutic avenues for treating myocardial injury and highlighting the potential of targeted exosome therapy in clinical settings.

Harmonising cellular conversations: decoding the vital roles of extracellular vesicles in respiratory system intercellular communications

Extracellular vesicles (EVs) released by various cells play crucial roles in intercellular communication within the respiratory system. This review explores the historical context and significance of research into extracellular vesicles. Categorised into exosomes (sized 30-150 nm), microvesicles (sized 50-1000 nm) and apoptotic bodies (sized 500-2000nm), based on their generation mechanisms, extracellular vesicles carry diverse cargoes of biomolecules, including proteins, lipids and nucleic acids. Respiratory ailments are the primary contributors to both mortality and morbidity across various populations globally, significantly impacting public health. Recent studies have underscored the pivotal role of extracellular vesicles, particularly their cargo content, in mediating intercellular communication between lung cells in respiratory diseases. This comprehensive review provides insights into extracellular vesicle mechanisms and emphasises their significance in major respiratory conditions, including acute lung injury, COPD, pulmonary hypertension, pulmonary fibrosis, asthma and lung cancer.

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.

The shared mechanism and potential diagnostic markers for premature ovarian failure and dry eye disease

Premature ovarian failure (POF), which is often comorbid with dry eye disease (DED) is a key issue affecting female health. Here, we explored the mechanism underlying comorbid POF and DED to further elucidate disease mechanisms and improve treatment. Datasets related to POF (GSE39501) and DED (GSE44101) were identified from the Gene Expression Omnibus (GEO) database and subjected to weighted gene coexpression network (WGCNA) and differentially expressed genes (DEGs) analyses, respectively, with the intersection used to obtain 158 genes comorbid in POF and DED. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses of comorbid genes revealed that identified genes were primarily related to DNA replication and Cell cycle, respectively. Protein-Protein interaction (PPI) network analysis of comorbid genes obtained the 15 hub genes: CDC20, BIRC5, PLK1, TOP2A, MCM5, MCM6, MCM7, MCM2, CENPA, FOXM1, GINS1, TIPIN, MAD2L1, and CDCA3. To validate the analysis results, additional POF- and DED-related datasets (GSE48873 and GSE171043, respectively) were selected. miRNAs-lncRNAs-genes network and machine learning methods were used to further analysis comorbid genes. The DGIdb database identified valdecoxib, amorfrutin A, and kaempferitrin as potential drugs. Herein, the comorbid genes of POF and DED were identified from a bioinformatics perspective, providing a new strategy to explore the comorbidity mechanism, opening up a new direction for the diagnosis and treatment of comorbid POF and DED.

The expression of MIR125B transcripts and bone phenotypes in Mir125b2-deficient mice

MIR125B, particularly its 5p strand, is apparently involved in multiple cellular processes, including osteoblastogenesis and osteoclastogenesis. Given that MIR125B is transcribed from the loci Mir125b1 and Mir125b2, three mature transcripts (MIR125B-5p, MIR125B1-3p, and MIR125B2-3p) are generated (MIR125B-5p is common to both); however, their expression profiles and roles in the bones remain poorly understood. Both primary and mature MIR125B transcripts were differentially expressed in various organs, tissues, and cells, and their expression patterns did not necessarily correlate in wild-type (WT) mice. We generated Mir125b2 knockout (KO) mice to examine the contribution of Mir125b2 to MIR125B expression profiles and bone phenotypes. Mir125b2 KO mice were born and grew normally without any changes in bone parameters. Interestingly, in WT and Mir125b2 KO, MIR125B-5p was abundant in the calvaria and bone marrow stromal cells. These results indicate that the genetic ablation of Mir125b2 does not impinge on the bones of mice, attracting greater attention to MIR125B-5p derived from Mir125b1. Future studies should investigate the conditional deletion of Mir125b1 and both Mir125b1 and Mir125b2 in mice.

Knockdown of TOP2A suppresses IL-17 signaling pathway and alleviates the progression of ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory disease of the colonic mucosa, with a gradually increasing incidence. Therefore, it is necessary to actively seek targets for the treatment of UC.

METHODS

Common differentially expressed genes (DEGs) were screened from two microarray data sets related to UC. Protein-protein interaction network was constructed to find the hub genes. The UC mouse model and cell model were induced by dextran sulfate sodium (DSS). The pathological changes of colon tissue were observed by hematoxylin-eosin staining. Immunohistochemistry and immunofluorescence were performed to detect the expressions of Ki67 and Claudin-1. The performance of mice was observed by disease activity index (DAI). The effect of TOP2A on proliferation, inflammation, oxidative stress, and interleukin-17 (IL-17) signaling pathway in UC model was measured by cell counting kit-8, enzyme-linked immunosorbent assay, and western blot.

RESULTS

Through bioinformatics analysis, 295 common DEGs were screened, and the hub gene TOP2A was selected. In UC model, there was obvious inflammatory cell infiltration in the colon and less goblet cells, while si-TOP2A lessened it. More Ki67 positive cells and less Claudin-1 positive cells were observed in UC model mice. Furthermore, knockdown of TOP2A increased the body weight and colon length of UC mice, while the DAI was decreased. Through in vivo and in vitro experiments, knockdown of TOP2A also inhibited inflammation and IL-17 signaling pathway, and promoted proliferation in DSS-induced NCM460 cells.

CONCLUSION

Knockdown of TOP2A alleviated the progression of UC by suppressing inflammation and inhibited IL-17 signaling pathway.

Deubiquitinase USP7 stabilizes KDM5B and promotes tumor progression and cisplatin resistance in nasopharyngeal carcinoma through the ZBTB16/TOP2A axis

Cisplatin-based chemotherapy improves the control of distant metastases in patients with nasopharyngeal carcinoma (NPC); however, around 30% of patients fail treatment due to acquired drug resistance. Epigenetic regulation is known to contribute to cisplatin resistance; nevertheless, the underlying mechanisms remain poorly understood. Here, we showed that lysine-specific demethylase 5B (KDM5B) was overexpressed and correlates with tumor progression and cisplatin resistance in patients with NPC. We also showed that specific inhibition of KDM5B impaired the progression of NPC and reverses cisplatin resistance, both in vitro and in vivo. Moreover, we found that KDM5B inhibited the expression of ZBTB16 by directly reducing H3K4me3 at the ZBTB16 promoter, which subsequently increased the expression of Topoisomerase II- α (TOP2A) to confer cisplatin resistance in NPC. In addition, we showed that the deubiquitinase USP7 was critical for deubiquitinating and stabilizing KDM5B. More importantly, the deletion of USP7 increased sensitivity to cisplatin by disrupting the stability of KDM5B in NPC cells. Therefore, our findings demonstrated that USP7 stabilized KDM5B and promoted cisplatin resistance through the ZBTB16/TOP2A axis, suggesting that targeting KDM5B may be a promising cisplatin-sensitization strategy in the treatment of NPC.

MicroRNA Profiles in Critically Ill Patients

The use of biomarkers to expedite diagnosis, prognostication, and treatment could significantly improve patient outcomes. The early diagnosis and treatment of critical illnesses can greatly reduce mortality and morbidity. Therefore, there is great interest in the discovery of biomarkers for critical illnesses. Micro-ribonucleic acids (miRNAs) are a highly conserved group of non-coding RNA molecules. They regulate the expression of genes involved in several developmental, physiological, and pathological processes. The characteristics of miRNAs suggest that they could be versatile biomarkers. Assay panels to measure the expression of several miRNAs could facilitate clinical decision-- making for a range of diseases. We have, in this paper, reviewed the current understanding of the role of miRNAs as biomarkers in critically ill patients.

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.

Exosomes: Potential Next-Generation Nanocarriers for the Therapy of Inflammatory Diseases

Inflammatory diseases are common pathological processes caused by various acute and chronic factors, and some of them are autoimmune diseases. Exosomes are fundamental extracellular vesicles secreted by almost all cells, which contain a series of constituents, i.e., cytoskeletal and cytosolic proteins (actin, tubulin, and histones), nucleic acids (mRNA, miRNA, and DNA), lipids (diacylglycerophosphates, cholesterol, sphingomyelin, and ceramide), and other bioactive components (cytokines, signal transduction proteins, enzymes, antigen presentation and membrane transport/fusion molecules, and adhesion molecules). This review will be a synopsis of the knowledge on the contribution of exosomes from different cell sources as possible therapeutic agents against inflammation, focusing on several inflammatory diseases, neurological diseases, rheumatoid arthritis and osteoarthritis, intestinal bowel disease, asthma, and liver and kidney injuries. Current knowledge indicates that the role of exosomes in the therapy of inflammation and in inflammatory diseases could be distinctive. The main limitations to their clinical translation are still production, isolation, and storage. Additionally, there is an urgent need to personalize the treatments in terms of the selection of exosomes; their dosages and routes of administration; and a deeper knowledge about their biodistribution, type and incidence of adverse events, and long-term effects of exosomes. In conclusion, exosomes can be a very promising next-generation therapeutic option, superior to synthetic nanocarriers and cell therapy, and can represent a new strategy of effective, safe, versatile, and selective delivery systems in the future.

A bibliometric analysis of exosomes in sepsis from 2004 to 2022

The study aims to summarize topical and frontier issues in sepsis and exosomes and provide advice and resources for researchers working in related disciplines. Publications on exosomes in sepsis from 2004 to 2022 were extracted from the Web of Science Core Collection database. VOSviewer 1.6.18 and CiteSpace 6.1.3 were used to conduct the bibliometric analysis. The number of publications on exosomes in sepsis showed a rapidly rising trend globally. China and the United States were the most published countries. Shanghai Jiao Tong University is the most prolific institution. Frontiers in Immunology was one of the journals with the highest number of papers. Journal of Immunology was the most co-cited journal. Ping Wang was the most productive author. Clotilde Thery was the author who has been cited the most times among co-cited authors. Singer m, 2016, Jama-j am med assoc was the most co-cited reference. "Mesenchymal stem cells derived exosomes," "microRNAs," "apoptosis," and "immunomodulatory therapy" are the current research hot spots and frontiers. This study provides a comprehensive overview of the current status and trends in sepsis and exosomal research. Researchers working in this area will benefit from the hot spots and trends of exosomes in sepsis discovered through this study.

Hyperoside Attenuates Sepsis-Induced Acute Lung Injury (ALI) through Autophagy Regulation and Inflammation Suppression

Background

Sepsis mortality and morbidity are aggravated by acute lung injury (ALI) or acute respiratory distress syndrome. Published studies have discovered that hyperoside (HYP) has an anti-inflammatory and therapeutic effect in many diseases. However, whether HYP treatment can attenuate sepsis-induced ALI is still obscure.

Methods

In this study, a cecal ligation and puncture (CLP)-induced sepsis mouse model was constructed. The mouse lungs were harvested and assessed using proteomics, immunohistochemistry, immunofluorescence, and enzyme-linked immunosorbent assay for pro-inflammatory cytokines. Human lung microvascular endothelial cells (HLMVECs) were induced with lipopolysaccharide (LPS) for the in vitro model.

Results

The results showed that HYP treatment attenuated sepsis-induced ALI through an increased survival rate, decreased inflammatory factor expression, and lung tissue apoptosis. At the same time, HYP pretreatment restored angiogenesis in CLP-induced mouse lung tissues. Proteomics detection showed that Atg13 played a vital role in HYP-mediated protection against sepsis-induced ALI. The in vitro experiment showed HYP treatment attenuated LPS-induced HLMVEC damage by regulating Atg13-mediated autophagy. Inhibiting autophagy or silencing Atg13 reversed the protective effect of HYP against sepsis-induced ALI.

Conclusion

Taken together, we conclude that HYP attenuated sepsis-induced ALI by regulating autophagy and inhibiting inflammation.

Small Extracellular Vesicles Secreted by iPSC-Derived MSCs Ameliorate Pulmonary Inflammation and Lung Injury Induced by Sepsis through Delivery of miR-125b-5p

Background

Sepsis-induced acute lung injury is a common critical illness in intensive care units with no effective treatment is currently available. Small extracellular vesicles, secreted by mesenchymal stem cells (MSCs), derived from human-induced pluripotent stem cells (iMSC-sEV), possess striking advantages when incorporated MSCs and iPSCs, which are considered extremely promising cell-free therapeutic agents. However, no studies have yet been conducted to systemically examine the effects and underlying mechanisms of iMSC-sEV application on attenuated lung injury under sepsis conditions.

Method

iMSC-sEV were intraperitoneally administered in a rat septic lung injury model induced by cecal ligation and puncture (CLP). The efficacy of iMSC-sEV was assessed by histology, immunohistochemistry, and pro-inflammatory cytokines of bronchoalveolar lavage fluid. We also evaluated the in vitro effects of iMSC-sEV on the activation of the inflammatory response in alveolar macrophages (AMs). Small RNA sequencing was utilized to detect changes in the miRNA expression profile in lipopolysaccharide (LPS)-treated AMs after iMSC-sEV administration. The effects of miR-125b-5p on the function of AMs were studied.

Results

iMSC-sEV were able to attenuate pulmonary inflammation and lung injury following CLP-induced lung injury. iMSC-sEV were internalized by AMs and alleviated the release of inflammatory factors by inactivating the NF-κB signaling pathway. Moreover, miR-125b-5p showed a fold-change in LPS-treated AMs after iMSC-sEV administration and was enriched in iMSC-sEV. Mechanistically, iMSC-sEV transmitted miR-125b-5p into LPS-treated AMs to target TRAF6.

Conclusion

Our findings demonstrated that iMSC-sEV treatment protects against septic lung injury and exerts anti-inflammatory effects on AMs at least partially through miR-125b-5p, suggesting that iMSC-sEV may provide a novel cell-free strategy for the treatment of septic lung injury.

Role of Extracellular microRNAs in Sepsis-Induced Acute Lung Injury

Acute lung injury (ALI) is a life-threatening pathological disease characterized by the damage of pulmonary endothelial cells and epithelial cell barriers by uncontrolled inflammation. During sepsis-induced ALI, multiple cells cooperate and communicate with each other to respond to the stimulation of inflammatory factors. However, the underlying mechanisms of action have not been fully identified, and the modes of communication therein are also being investigated. Extracellular vesicles (EVs) are a heterogeneous population of spherical membrane structures released by almost all types of cells, containing various cellular components. EVs are primary transport vehicles for microRNAs (miRNAs), which play essential roles in physiological and pathological processes in ALI. EV miRNAs from different sources participated in regulating the biological function of pulmonary epithelial cells, endothelial cells, and phagocytes by transferring miRNA through EVs during ALI induced by sepsis, which has great potential diagnostic and therapeutic values. This study aims to summarize the role and mechanism of extracellular vesicle miRNAs from different cells in the regulation of sepsis-induced ALI. It provides ideas for further exploring the role of extracellular miRNA secreted by different cells in the ALI induced by sepsis, to make up for the deficiency of current understanding, and to explore the more optimal scheme for diagnosis and treatment of ALI.

Topoisomerases in Immune Cell Development and Function

DNA topoisomerases (TOPs) are complex enzymatic machines with extraordinary capacity to maintain DNA topology during torsion-intensive steps of replication and transcription. Recently, TOPs have gained significant attention for their tissue-specific function, and the vital role of TOPs in immune homeostasis and dysfunction is beginning to emerge. TOPs have been implicated in various immunological disorders such as autoimmunity, B cell immunodeficiencies, and sepsis, underscoring their importance in immune regulation. However, much remains unknown about immunological underpinnings of TOPs, and a deeper understanding of the role of TOPs in the immune system will be critical for yielding significant insights into the etiology of immunological disorders. In this review, we first discuss the recent literature highlighting the contribution of TOPs in the development of immune cells, and we further provide an overview of their importance in immune cell responses.

Endothelial progenitor cells in the host defense response

Extensive injury of endothelial cells in blood vasculature, especially in the microcirculatory system, frequently occurs in hosts suffering from sepsis and the accompanied systemic inflammation. Pathological factors, including toxic components derived from invading microbes, oxidative stress associated with tissue ischemia/reperfusion, and vessel active mediators generated during the inflammatory response, are known to play important roles in mediating endothelial injury. Collapse of microcirculation and tissue edema developed from the failure of endothelial barrier function in vital organ systems, including the lung, brain, and kidney, are detrimental, which often predict fatal outcomes. The host body possesses a substantial capacity for maintaining vascular homeostasis and repairing endothelial damage. Bone marrow and vascular wall niches house endothelial progenitor cells (EPCs). In response to septic challenges, EPCs in their niche environment are rapidly activated for proliferation and angiogenic differentiation. In the meantime, release of EPCs from their niches into the blood stream and homing of these vascular precursors to tissue sites of injury are markedly increased. The recruited EPCs actively participate in host defense against endothelial injury and repair of damage in blood vasculature via direct differentiation into endothelial cells for re-endothelialization as well as production of vessel active mediators to exert paracrine and autocrine effects on angiogenesis/vasculogenesis. In recent years, investigations on significance of EPCs in host defense and molecular signaling mechanisms underlying regulation of the EPC response have achieved substantial progress, which promotes exploration of vascular precursor cell-based approaches for effective prevention and treatment of sepsis-induced vascular injury as well as vital organ system failure.

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.

Upregulation of microRNA-125b-5p alleviates acute liver failure by regulating the Keap1/Nrf2/HO-1 pathway

BACKGROUND

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) are the two most common subtypes of liver failure. They are both life-threatening clinical problems with high short-term mortality. Although liver transplantation is an effective therapeutic, its application is limited due to the shortage of donor organs. Given that both ACLF and ALF are driven by excessive inflammation in the initial stage, molecules targeting inflammation may benefit the two conditions. MicroRNAs (miRNAs) are a group of small endogenous noncoding interfering RNA molecules. Regulation of miRNAs related to inflammation may serve as promising interventions for the treatment of liver failure.

AIMS

To explore the role and mechanism of miR-125b-5p in the development of liver failure.

METHODS

Six human liver tissues were categorized into HBV-non-ACLF and HBV-ACLF groups. Differentially expressed miRNAs (DE-miRNAs) were screened and identified through high-throughput sequencing analysis. Among these DE-miRNAs, miR-125b-5p was selected for further study of its role and mechanism in lipopolysaccharide (LPS)/D-galactosamine (D-GalN) -challenged Huh7 cells and mice in vitro and in vivo.

RESULTS

A total of 75 DE-miRNAs were obtained. Of these DE-miRNAs, miR-125b-5p was the focus of further investigation based on our previous findings and preliminary results. We preliminarily observed that the levels of miR-125b-5p were lower in the HBV-ACLF group than in the HBV-non-ACLF group. Meanwhile, LPS/D-GalN-challenged mice and Huh7 cells both showed decreased miR-125b-5p levels when compared to their untreated control group, suggesting that miR-125b-5p may have a protective role against liver injury, regardless of ACLF or ALF. Subsequent results revealed that miR-125b-5p not only inhibited Huh7 cell apoptosis in vitro but also relieved mouse ALF in vivo with evidence of improved liver histology, decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and reduced tumor necrosis factor-α (TNF-α) and IL-1β levels. Based on the results of a biological prediction website, microRNA.org, Kelch-like ECH-associated protein 1 (Keap1) was predicted to be one of the target genes of miR-125b-5p, which was verified by a dual-luciferase reporter gene assay. Western blot results in vitro and in vivo showed that miR-125b-5p could decrease the expression of Keap1 and cleaved caspase-3 while upregulating the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1(HO-1).

CONCLUSION

Upregulation of miR-125b-5p can alleviate acute liver failure by regulating the Keap1/Nrf2/HO-1 pathway, and regulation of miR-125b-5p may serve as an alternative intervention for liver failure.

Expression of MicroRNAs in Sepsis-Related Organ Dysfunction: A Systematic Review

Sepsis is a critical condition characterized by increased levels of pro-inflammatory cytokines and proliferating cells such as neutrophils and macrophages in response to microbial pathogens. Such processes lead to an abnormal inflammatory response and multi-organ failure. MicroRNAs (miRNA) are single-stranded non-coding RNAs with the function of gene regulation. This means that miRNAs are involved in multiple intracellular pathways and thus contribute to or inhibit inflammation. As a result, their variable expression in different tissues and organs may play a key role in regulating the pathophysiological events of sepsis. Thanks to this property, miRNAs may serve as potential diagnostic and prognostic biomarkers in such life-threatening events. In this narrative review, we collect the results of recent studies on the expression of miRNAs in heart, blood, lung, liver, brain, and kidney during sepsis and the molecular processes in which they are involved. In reviewing the literature, we find at least 122 miRNAs and signaling pathways involved in sepsis-related organ dysfunction. This may help clinicians to detect, prevent, and treat sepsis-related organ failures early, although further studies are needed to deepen the knowledge of their potential contribution.

Advances in the use of exosomes for the treatment of ALI/ARDS

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a critical clinical syndrome with high morbidity and mortality. Currently, the primary treatment for ALI/ARDS is mainly symptomatic therapy such as mechanical ventilation and fluid management. Due to the lack of effective treatment strategies, most ALI/ARDS patients face a poor prognosis. The discovery of exosomes has created a promising prospect for the treatment of ALI/ARDS. Exosomes can exert anti-inflammatory effects, inhibit apoptosis, and promote cell regeneration. The microRNA contained in exosomes can participate in intercellular communication and play an immunomodulatory role in ALI/ARDS disease models. This review discusses the possible mechanisms of exosomes in ALI/ARDS to facilitate the development of innovative treatments for ALI/ARDS.

Modes of action and diagnostic value of miRNAs in sepsis

Sepsis is a clinical syndrome defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis is a major public health concern associated with one in five deaths worldwide. Sepsis is characterized by unbalanced inflammation and profound and sustained immunosuppression, increasing patient susceptibility to secondary infections and mortality. microRNAs (miRNAs) play a central role in the control of many biological processes, and deregulation of their expression has been linked to the development of oncological, cardiovascular, neurodegenerative and metabolic diseases. In this review, we discuss the role of miRNAs in sepsis pathophysiology. Overall, miRNAs are seen as promising biomarkers, and it has been proposed to develop miRNA-based therapies for sepsis. Yet, the picture is not so straightforward because of the versatile and dynamic features of miRNAs. Clearly, more research is needed to clarify the expression and role of miRNAs in sepsis, and to promote the use of miRNAs for sepsis management.

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.

RETRACTED: Exosomal microRNA-16-5p from adipose mesenchymal stem cells promotes TLR4-mediated M2 macrophage polarization in septic lung injury

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The authors have requested that this paper be retracted as they were unable to replicate the experimental data reported in Figure 1A. The authors posit that changes in reagents or experimental conditions might be the source of their inability to do so. Additional concerns were raised about the reliability of the Western blot results in Figure 1E, Figure 4B and F, Figure 5B, and Figure 6B, as regarding ‘morphology space’ similarities contained within a series of papers with distinctive eyebrow blots, tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0 [nam11.safelinks.protection.outlook.com] [nam11.safelinks.protection.outlook.com]). The journal requested the authors comment on these concerns and provide raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

GYY4137 protected the integrity of the blood-brain barrier via activation of the Nrf2/ARE pathway in mice with sepsis

Injury to the blood-brain barrier (BBB) plays a vital role in sepsis-associated encephalopathy (SAE), which is one of the most common complications of sepsis. GYY4137, a new synthetic compound of hydrogen sulfide (H₂ S), has extensive biological benefits. In this study, we focused on the protective effects of GYY4137 on the BBB in septic mice and the underlying mechanisms. The results suggested that whether administrated at the same time or 3 hours after LPS injection, GYY4137 both significantly alleviated the clinical symptoms and the long-term prognosis. Besides, GYY4137 improved the pathological abnormalities of septic mice. Moreover, the degradation of tight junctions in the BBB was considerably inhibited by GYY4137. In addition, GYY4137 significantly attenuated inflammation and apoptosis in the brain. Furthermore, GYY4137 activated the Nrf2/ARE pathway through the sulfhydrylation of Keap1 and inhibited oxidative stress. ML385, the specific inhibitor of Nrf2, significantly reversed the protective effects of GYY4137 in sepsis mice. In conclusion, this study indicated that through the sulfhydrylation of Keap1, GYY4137 activated the Nrf2/ARE pathway and exerted anti-inflammatory, anti-apoptotic and antioxidant effects in septic mice that consequently protected the integrity of the BBB and improved the clinical outcome of sepsis. Our findings suggest that GYY4137 might be a promising agent for the treatment of SAE.