Human hepatocyte-derived extracellular vesicles attenuate the carbon tetrachloride-induced acute liver injury in mice

Pathogenesis and interaction of neutrophils and extracellular vesicles in noncancer liver diseases

Liver disease ranks as the eleventh leading cause of mortality, leading to approximately 2 million deaths annually worldwide. Neutrophils are a type of immune cell that are abundant in peripheral blood and play a vital role in innate immunity by quickly reaching the site of liver injury. They exert their influence on liver diseases through autocrine, paracrine, and immunomodulatory mechanisms. Extracellular vesicles, phospholipid bilayer vesicles, transport a variety of substances, such as proteins, nucleic acids, lipids, and pathogenic factors, for intercellular communication. They regulate cell communication and perform their functions by delivering biological information. Current research has revealed the involvement of the interaction between neutrophils and extracellular vesicles in the pathogenesis of liver disease. Moreover, more research has focused on targeting neutrophils as a therapeutic strategy to attenuate disease progression. Therefore, this article summarizes the roles of neutrophils, extracellular vesicles, and their interactions in noncancerous liver diseases.

Dexmedetomidine and argon in combination against ferroptosis through tackling TXNIP-mediated oxidative stress in DCD porcine livers

Graft availability from donation after circulatory death (DCD) is significantly limited by ischaemia reperfusion (IR) injury. Effective strategies to mitigate IR injury in DCD grafts are essential to improve graft quality and expand the donor pool. In this study, liver grafts from DCD pigs were preserved in the University of Wisconsin (UW) solution saturated with 0.1 nM dexmedetomidine (Dex) and various concentrations of noble gases Argon (Ar) and/or Xenon (Xe) at 4 °C for 24 or 72 h. The combined 50% Ar and Dex provided maximum protection to liver grafts by reducing morphological damage, apoptosis, necroptosis, ferroptosis, hepatocyte glycogen depletion, reticulin framework collapse, iron deposition, and oxidative stress. In vitro, human liver Hep G2 cells were preserved in the UW solution saturated with 0.1 nM Dex and 50% Ar in combination at 4 °C for 24 h, followed by recovery in medium at 37 °C for up to 48 h to mimic clinical IR injury. This treatment significantly increased the expression of anti-oxidative stress proteins by promoting the translocation of thioredoxin-interacting protein (TXNIP) to mitochondria, thereby inhibiting ferroptosis, increasing plasma membrane integrity, and maintaining cell viability.In summary, The combination of 0.1 nM Dex and 50% Ar may be a promising strategy to reduce ferroptosis and other form cell death, and preserve liver grafts.

Chromatographic purification of small extracellular vesicles using an affinity column for phospholipid membranes

OBJECTIVES

This study aimed to investigate whether chromatography using an ExoPUA column, an affinity column for phospholipid membranes, could potentially serve as an efficient, rapid, scalable, and reproducible method for purifying small extracellular vesicles (sEVs).

RESULTS

We used the ExoPUA column connected to a fast-performance liquid chromatography system. One-step chromatographic purification of sEVs from culture supernatant using the ExoPUA protocol resulted in an 82 ± 16-fold increase in purity with a yield of 38 ± 5% of sEVs. The purified sEVs contained CD9, CD63, TSG101, and miRNA (miR-21), but not the endoplasmic reticulum protein Calnexin. Transmission electron microscopy indicated that the purified sEVs were intact. The purification performance of the ExoPUA protocol showed superior results in terms of yield compared to that of the differential ultracentrifugation method, the most commonly used method for purifying sEVs in laboratories, and purity compared to that of the DEAE chromatography protocol.

CONCLUSION

The sEVs were effectively purified in the bind-elute mode and the ExoPUA column can be refreshed and sterilized with sodium hydroxide (NaOH), having high potential for multiple sEV purification in a scalable and industrial manner.

Liver-derived extracellular vesicles from patients with hepatitis B virus-related acute-on-chronic liver failure impair hepatic regeneration by inhibiting on FGFR2 signaling via miR-218-5p

BACKGROUND

Impaired liver regeneration in hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) patients is closely related to prognosis; however, the mechanisms are not yet defined. Liver-derived extracellular vesicles (EVs) may be involved in the dysregulation of liver regeneration. Clarifying the underlying mechanisms will improve the treatments for HBV-ACLF.

METHODS

EVs were isolated by ultracentrifugation from liver tissues of HBV-ACLF patients (ACLF_EVs) after liver transplantation, and their function was investigated in acute liver injury (ALI) mice and AML12 cells. Differentially expressed miRNAs (DE-miRNAs) were screened by deep miRNA sequencing. The lipid nanoparticle (LNP) system was applied as a carrier for the targeted delivery of miRNA inhibitors to improve its effect on liver regeneration.

RESULTS

ACLF_EVs inhibited hepatocyte proliferation and liver regeneration, with a critical role of miR-218-5p. Mechanistically, ACLF_EVs fused directly with target hepatocytes and transferred miR-218-5p into hepatocytes, acting by suppressing FGFR2 mRNA and inhibiting the activation of ERK1/2 signaling pathway. Reducing the level of miR-218-5p expression in the liver of ACLF mice partially restored liver regeneration ability.

CONCLUSION

The current data reveal the mechanism underlying impaired liver regeneration in HBV-ACLF that promotes the discovery of new therapeutic approaches.

Effect of gut microbiome-derived metabolites and extracellular vesicles on hepatocyte functions in a gut-liver axis chip

Metabolism, is a complex process involving the gut and the liver tissue, is difficult to be reproduced in vitro with conventional single cell culture systems. To tackle this challenge, we developed a gut-liver-axis chip consisting of the gut epithelial cell chamber and three-dimensional (3D) uniform-sized liver spheroid chamber. Two cell culture chamber compartments were separated with a porous membrane to prevent microorganisms from passing through the chamber. When the hepG2 spheroids cultured with microbiota-derived metabolites, we observed the changes in the physiological function of hepG2 spheroids, showing that the albumin and urea secretion activity of liver spheroids was significantly enhanced. Additionally, the functional validation of hepG2 spheroids treated with microbiota-derived exosome was evaluated that the treatment of the microbiota-derived exosome significantly enhanced albumin and urea in hepG2 spheroids in a gut-liver axis chip. Therefore, this gut-liver axis chip could be a potentially powerful co-culture platform to study the interaction of microbiota and host cells.

Identification of key immune-related genes associated with LPS/D-GalN-induced acute liver failure in mice based on transcriptome sequencing

Background

The aim of this study was to identify key immune-related genes in acute liver failure (ALF) by constructing an ALF mouse model for transcriptome sequencing.

Methods

The C57BL/6 mouse with ALF model was induced by lipopolysaccharide (LPS)/ D-galactosamine (D-GalN). After successful modelling, the liver tissues of all mice were obtained for transcriptome sequencing. The key immune-related genes in mice with ALF were identified by differential expression analysis, immune infiltration analysis, weighted gene co-expression network analysis (WGCNA), enrichment analysis, and protein-protein interaction (PPI) analysis.

Results

An LPS/D-GalN-induced ALF mouse model was successfully constructed, and transcriptome sequencing was performed. Significant differences in the proportions of monocytes, macrophages M0, macrophages M1 and neutrophils were shown by immune infiltration analysis, and 5255 genes highly associated with these four immune cells were identified by WGCNA. These immune genes were found to be significantly enriched in the TNF signalling pathway by enrichment analysis. Finally, PPI analysis was performed on genes enriched in this pathway and three key genes (CXCL1, CXCL10 and IL1B) were screened out and revealed to be significantly upregulated in ALF.

Conclusions

Key immune-related genes in ALF were identified in this study, which may provide not only potential therapeutic targets for treating ALF and improving its prognosis, but also a reliable scientific basis for the immunotherapy of the disease.

Extracellular vesicles as potential biomarkers and treatment options for liver failure: A systematic review up to March 2022

Introduction

Extracellular vesicles (EVs) carrying functional cargoes are emerging as biomarkers and treatment strategies in multiple liver diseases. Nevertheless, the potential of EVs in liver failure remains indistinct. In this systematic review, we comprehensively analyzed the potential of EVs as biomarkers of liver failure and the therapeutic effects and possible mechanisms of EVs for liver failure.

Methods

We conducted a systematic review by comprehensively searching the following electronic databases: PubMed, Web of Science, Embase and Cochrane Central Register of Controlled Trials from inception to March 2022. The used text words (synonyms and word variations) and database-specific subject headings included "Extracellular Vesicles", "Exosomes", "Liver Failure", "Liver Injury", etc.

Results

A total of 1479 studies were identified. After removing 680 duplicate studies and 742 irrelevant studies, 57 studies were finally retained and analyzed. Fourteen studies revealed EVs with functional cargoes could be used to make the diagnosis of liver failure and provide clues for early warning and prognostic assessment of patients with liver failure. Forty-three studies confirmed the administration of EVs from different sources alleviated hepatic damage and improved survival through inhibiting inflammatory response, oxidative stress as well as apoptosis or promoting hepatocyte regeneration and autophagy.

Conclusions

EVs and their cargoes can be used not only as superior biomarkers of early warning, early diagnosis and prognostic assessments for liver failure, but also as potentially effective treatment options for liver failure. In the future, large-scale studies are urgently needed to verify the diagnostic, predictive and therapeutic value of EVs for liver failure.

Role of Small Extracellular Vesicles in Liver Diseases: Pathogenesis, Diagnosis, and Treatment

Extracellular vesicles (EVs) are vesicular bodies that bud off from the cell membrane or are secreted virtually by all cell types. Small EVs (sEVs or exosomes) are key mediators of cell-cell communication by delivering their cargo, including proteins, lipids, or RNAs, to the recipient cells where they induce changes in signaling pathways and phenotypic properties. Tangible findings have revealed the pivotal involvement of sEVs in the pathogenesis of various diseases. On the bright side, they are rich sources of biomarkers for diagnosis, prognosis, treatment response, and disease monitoring. sEVs have high stability, biocompatibility, targetability, low toxicity, and are immunogenic in nature. Their intrinsic properties make sEVs an ideal delivery vehicle to be loaded with cargo for therapeutic interventions. Liver diseases are a major global health problem. This review aims to focus on the roles and mechanisms of sEVs in the pathogenesis of liver diseases, liver injury, liver failure, and liver cancer. sEVs are released not only by hepatocytes but also by stromal and immune cells in the microenvironment. Early detection of liver disease determines the chance for curative treatment and high survival of patients. This review focuses on the potential of circulating sEV cargo as specific and sensitive noninvasive biomarkers for the early detection and prognosis of liver diseases. In addition, the therapeutic use of sEVs derived from various cell types is discussed. Although sEVs hold promise for clinical applications, there are still challenges to be overcome by further research to bring utilization of sEVs into clinical practice.