Causal Relationship Between Gut Microbiota and Liver Cirrhosis: 16S rRNA Sequencing and Mendelian Randomization Analyses.

Background and Aims: Accumulating evidence highlights the association between the gut microbiota and liver cirrhosis. However, the role of the gut microbiota in liver cirrhosis remains unclear. Methods: We first assessed the differences in the composition of the bacterial community between CCl4-induced liver cirrhosis and control mice using 16S rRNA sequencing. We then performed a two-sample Mendelian randomization (MR) analysis to reveal the underlying causal relationship between the gut microbiota and liver cirrhosis. Causal relationships were analyzed using primary inverse variance weighting (IVW) and other supplemental MR methods. Furthermore, fecal samples from liver cirrhosis patients and healthy controls were collected to validate the results of the MR analysis. Results: Analysis of 16S rRNA sequencing indicated significant differences in gut microbiota composition between the cirrhosis and control groups. IVW analyses suggested that Alphaproteobacteria, Bacillales, NB1n, Rhodospirillales, Dorea, Lachnospiraceae, and Rhodospirillaceae were positively correlated with the risk of liver cirrhosis, whereas Butyricicoccus, Hungatella, Marvinbryantia, and Lactobacillaceae displayed the opposite effects. However, the weighted median and MR-PRESSO estimates further showed that only Butyricicoccus and Marvinbryantia presented stable negative associations with liver cirrhosis. No significant heterogeneity or horizontal pleiotropy was observed in the sensitivity analysis. Furthermore, the result of 16S rRNA sequencing also showed that healthy controls had a higher relative abundance of Butyricicoccus and Marvinbryantia than liver cirrhosis patients. Conclusions: Our study provides new causal evidence for the link between gut microbiota and liver cirrhosis, which may contribute to the discovery of novel strategies to prevent liver cirrhosis.

Human umbilical cord-derived mesenchymal stem cells ameliorate liver fibrosis by improving mitochondrial function via Slc25a47-Sirt3 signaling pathway.

Chronic Liver fibrosis may progress to liver cirrhosis and hepatocellular carcinoma (HCC), hence cause a substantial global burden. However, effective therapies for blocking fibrosis are still lacking. Although mesenchymal stem cells (MSCs) have been proven beneficial to liver regeneration after damage, the underlying mechanism of their therapeutic effects are not fully understood. Oxidative stress and mitochondrial functionality alteration directly contributes to the hepatocyte apoptosis and development of liver fibrosis. This study aims to elucidate the mechanism by which hUC-MSC alleviates liver fibrosis and mitochondrial dysfunction. RNA-sequencing was performed to characterize the transcriptomic changes after implantation of hUC-MSCs in mice with liver fibrosis. Next, western blot, RT-PCR, immunohistochemical and immunofluorescence staining were used to evaluate the expression of different genes in vitro and in vivo. Additionally, mitochondrial morphological and dynamic changes, ROS content, and ATP production were examined. Slc25a47, a newly identified liver-specific mitochondrial NAD+ transporter, was notably reduced in CCl4-treated mice and H2O2-stimulated hepatocytes. Conversely, hUC-MSCs increased the Slc25a47 expression and NAD+ level within mitochondria, thereby enhanced Sirt3 protein activity and alleviated mitochondrial dysfunction in the liver. Furthermore, Slc25a47 knockdown could partially abrogate the protective effects of hUC-MSCs on H2O2-induced mitochondrial fission and oxidative stress in hepatocytes. Our study illustrates that Slc25a47 is a key molecular for hUC-MSCs to improve liver fibrosis and regulates mitochondrial function through Sirt3 for the first time, and providing a theoretical basis for the clinical translation of hUC-MSCs transplantation in the treatment of patients with liver fibrosis/cirrhosis.

Hypertension and NAFLD risk: Insights from the NHANES 2017-2018 and Mendelian randomization analyses.

BACKGROUND: Hypertension and non-alcoholic fatty liver disease (NAFLD) share several pathophysiologic risk factors, and the exact relationship between the two remains unclear. Our study aims to provide evidence concerning the relationship between hypertension and NAFLD by analyzing data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018 and Mendelian randomization (MR) analyses. METHODS: Weighted multivariable-adjusted logistic regression was applied to assess the relationship between hypertension and NAFLD risk by using data from the NHANES 2017-2018. Subsequently, a two-sample MR study was performed using the genome-wide association study (GWAS) summary statistics to identify the causal association between hypertension, systolic blood pressure (SBP), diastolic blood pressure (DBP), and NAFLD. The primary inverse variance weighted (IVW) and other supplementary MR approaches were conducted to verify the causal association between hypertension and NAFLD. Sensitivity analyses were adopted to confirm the robustness of the results. RESULTS: A total of 3144 participants were enrolled for our observational study in NHANES. Weighted multivariable-adjusted logistic regression analysis suggested that hypertension was positively related to NAFLD risk (odds ratio [OR] = 1.677; 95% confidence interval [CI], 1.159-2.423). SBP ≥130 mmHg and DBP ≥80 mmHg were also significantly positively correlated with NAFLD. Moreover, hypertension was independently connected with liver steatosis ( ß = 7.836 [95% CI, 2.334-13.338]). The results of MR analysis also supported a causal association between hypertension (OR = 7.203 [95% CI, 2.297-22.587]) and NAFLD. Similar results were observed for the causal exploration between SBP (OR = 1.024 [95% CI, 1.003-1.046]), DBP (OR = 1.047 [95% CI, 1.005-1.090]), and NAFLD. The sensitive analysis further confirmed the robustness and reliability of these findings (all P >0.05). CONCLUSION: Hypertension was associated with an increased risk of NAFLD.

Human umbilical cord mesenchymal stem cells inhibit liver fibrosis via the microRNA-148a-5p/SLIT3 axis.

BACKGROUND: Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have garnered considerable attention as prospective modalities of treatment for liver fibrosis (LF). The inhibition of hepatic stellate cell (HSC) activation underlies the anti-fibrotic effects of hUC-MSCs. However, the precise mechanism by which hUC-MSCs impede HSC activation remains unclarified. We aimed to elucidate the intrinsic mechanisms underlying the therapeutic effects of hUC-MSCs in LF patients. METHODS: Mice with liver cirrhosis induced by carbon tetrachloride (CCl4) were used as experimental models and administered hUC-MSCs via tail-vein injection. The alterations in inflammation and fibrosis were evaluated through histopathological examinations. RNA sequencing (RNA-seq) and bioinformatics analysis were then conducted to investigate the therapeutic mechanism of hUC-MSCs. Finally, an in-vitro experiment involving the co-cultivation of hUC-MSCs or hUC-MSC-derived exosomes (MSC-Exos) with LX2 cells was performed to validate the potential mechanism underlying the hepatoprotective effects of hUC-MSCs in LF patients. RESULTS: hUC-MSC therapy significantly improved liver function and alleviated LF in CCl4-induced mice. High-throughput RNA-Seq analysis identified 1142 differentially expressed genes that were potentially involved in mediating the therapeutic effects of hUC-MSCs. These genes play an important role in regulating the extracellular matrix. miRNA expression data (GSE151098) indicated that the miR-148a-5p level was downregulated in LF samples, but restored following hUC-MSC treatment. miR-148a-5p was delivered to LX2 cells by hUC-MSCs via the exosome pathway, and the upregulated expression of miR-148a-5p significantly suppressed the expression of the activated phenotype of LX2 cells. SLIT3 was identified within the pool of potential target genes regulated by miR-148a-5p. Furthermore, hUC-MSC administration upregulated the expression of miR-148a-5p, which played a crucial role in suppressing the expression of SLIT3, thereby palliating fibrosis. CONCLUSIONS: hUC-MSCs inhibit the activation of HSCs through the miR-148a-5p/SLIT3 pathway and are thus capable of alleviating LF.

Advancements in mesenchymal stem cell therapy for liver cirrhosis: Unveiling origins, treatment mechanisms, and current research frontiers.

Chronic liver disease inevitably progresses to liver cirrhosis, significantly compromising patients' overall survival and quality of life. However, a glimmer of hope emerges with the emergence of mesenchymal stem cells, possessing remarkable abilities for self-renewal, differentiation, and immunomodulation. Leveraging their potential, MSCs have become a focal point in both basic and clinical trials, offering a promising therapeutic avenue to impede fibrosis progression and enhance the life expectancy of individuals battling hepatic cirrhosis. This comprehensive review serves to shed light on the origin of MSCs, the intricate mechanisms underlying cirrhosis treatment, and the cutting-edge advancements in basic and clinical research surrounding MSC-based therapies for liver cirrhosis patients.

IGF2-NR4A2 Signaling Regulates Macrophage Subtypes to Attenuate Liver Cirrhosis.

Background and Aims: Liver cirrhosis can lead to liver failure and eventually death. Macrophages are the main contributors to cirrhosis and have a bidirectional role in regulating matrix deposition and degradation. Macrophage-based cell therapy has been developed as an alternative to liver transplantation. However, there is insufficient evidence regarding its safety and efficacy. In this study, we aimed to explore the effect of combining insulin-like growth factor 2 (IGF2) with bone marrow-derived macrophages (BMDMs) to treat mice with liver cirrhosis. Methods: We assessed liver inflammation, fibrosis regression, liver function, and liver regeneration in mice with CCl4-induced cirrhosis and treated with BMDM only or IGF2 + BMDM. We performed in vitro experiments in which activated hepatic stellate cells (HSCs) were co-cultured with macrophages in the presence or absence of IGF2. The polarity of macrophages and the degree of inhibition of HSCs were examined. The effect of IGF2 on macrophages was also verified by the overexpression of IGF2. Results: Combining IGF2 with BMDM reduced liver inflammation and fibrosis and increased hepatocyte proliferation. Combining IGF2 with BMDM was more effective than using BMDM alone. In vitro experiments demonstrated that IGF2 inhibited HSCs activation by upregulating NR4A2 to promote the anti-inflammatory macrophages phenotype. IGF2 also increased the synthesis of matrix metalloproteinases (MMPs) by macrophages, which may explain why administering IGF2 combined with BMDM was more effective than administering BMDM only. Conclusions: Our study provides a theoretical basis for the future use of BMDM-based cell therapy to treat liver cirrhosis.

Human umbilical cord-derived mesenchymal stromal cells alleviate liver cirrhosis through the Hippo/YAP/Id1 pathway and macrophage-dependent mechanism.

BACKGROUND: Few effective anti-fibrotic therapies are currently available for liver cirrhosis. Mesenchymal stromal cells (MSCs) ameliorate liver fibrosis and contribute to liver regeneration after cirrhosis, attracting much attention as a potential therapeutic strategy for the disease. However, the underlying molecular mechanism of their therapeutic effect is still unclear. Here, we investigated the effect of human umbilical cord-derived mesenchymal stromal cells (hUC-MSCs) in treating liver cirrhosis and their underlying mechanisms. METHODS: We used carbon tetrachloride (CCl4)-induced mice as liver cirrhosis models and treated them with hUC-MSCs via tail vein injection. We assessed the changes in liver function, inflammation, and fibrosis by histopathology and serum biochemistry and explored the mechanism of hUC-MSCs by RNA sequencing (RNA-seq) using liver tissues. In addition, we investigated the effects of hUC-MSCs on hepatic stellate cells (HSC) and macrophages by in vitro co-culture experiments. RESULTS: We found that hUC-MSCs considerably improved liver function and attenuated liver inflammation and fibrosis in CCl4-injured mice. We also showed that these cells exerted therapeutic effects by regulating the Hippo/YAP/Id1 axis in vivo. Our in vitro experiments demonstrated that hUC-MSCs inhibit HSC activation by regulating the Hippo/YAP signaling pathway and targeting Id1. Moreover, hUC-MSCs also alleviated liver inflammation by promoting the transformation of macrophages to an anti-inflammatory phenotype. CONCLUSIONS: Our study reveals that hUC-MSCs relieve liver cirrhosis in mice through the Hippo/YAP/Id1 pathway and macrophage-dependent mechanisms, providing a theoretical basis for the future use of these cells as a potential therapeutic strategy for patients with liver cirrhosis.

Recent advances in the immunomodulation mechanism of mesenchymal stem cell therapy in liver diseases.

Liver fibrosis, acute liver injury or liver failure, liver tumors, and immune rejection after liver transplantation are common clinical liver diseases. Immune responses are the key to determining the prognosis of liver diseases. Liver transplantation could be the last resort for patients with liver failure. However, the use of liver transplantation is limited because of the scarcity of organ donors, immunological rejection in recipients, and high cost. Mesenchymal stem cells (MSCs) are pluripotent adult stem cells with extensive anti-inflammatory and immunomodulation effects. MSCs can be effectively used for treating liver diseases but without the limitations that are associated with liver transplantation. Therefore, several clinical trials have utilized MSCs for the treatment of refractory liver diseases and the related mechanism is increasingly being elucidated. We have mainly summarized the recent studies that focus on the immunomodulation mechanism of MSC therapy in liver diseases. Further, we have presented our insights on the prospects of using MSCs in the treatment of liver diseases.

Integrated Bioinformatics and Validation Reveal IFI27 and Its Related Molecules as Potential Identifying Genes in Liver Cirrhosis.

Liver cirrhosis remains a significant global public health concern, with liver transplantation standing as the foremost effective treatment currently available. Therefore, investigating the pathogenesis of liver cirrhosis and developing novel therapies is imperative. Mitochondrial dysfunction stands out as a pivotal factor in its development. This study aimed to elucidate the relationship between mitochondria dysfunction and liver cirrhosis using bioinformatic methods to unveil its pathogenesis. Initially, we identified 460 co-expressed differential genes (co-DEGs) from the GSE14323 and GSE25097 datasets, alongside their combined datasets. Functional analysis revealed that these co-DEGs were associated with inflammatory cytokines and cirrhosis-related signaling pathways. Utilizing weighted gene co-expression network analysis (WCGNA), we screened module genes, intersecting them with co-DEGs and oxidative stress-related mitochondrial genes. Two algorithms (least absolute shrinkage and selection operator (LASSO) regression and SVE-RFE) were then employed to further analyze the intersecting genes. Finally, COX7A1 and IFI27 emerged as identifying genes for liver cirrhosis, validated through a receiver operating characteristic (ROC) curve analysis and related experiments. Additionally, immune infiltration highlighted a strong correlation between macrophages and cirrhosis, with the identifying genes (COX7A1 and IFI27) being significantly associated with macrophages. In conclusion, our findings underscore the critical role of oxidative stress-related mitochondrial genes (COX7A1 and IFI27) in liver cirrhosis development, highlighting their association with macrophage infiltration. This study provides novel insights into understanding the pathogenesis of liver cirrhosis.

Comprehensive bioinformatics and machine learning analysis identify VCAN as a novel biomarker of hepatitis B virus-related liver fibrosis.

Hepatitis B virus (HBV) infection remains the leading cause of liver fibrosis (LF) worldwide, especially in China. Identification of decisive diagnostic biomarkers for HBV-associated liver fibrosis (HBV-LF) is required to prevent chronic hepatitis B (CHB) from progressing to liver cancer and to more effectively select the best treatment strategy. We obtained 43 samples from CHB patients without LF and 81 samples from CHB patients with LF (GSE84044 dataset). Among these, 173 differentially expressed genes (DEGs) were identified. Functional analysis revealed that these DEGs predominantly participated in immune-, extracellular matrix-, and metabolism-related processes. Subsequently, we integrated four algorithms (LASSO regression, SVM-RFE, RF, and WGCNA) to determine diagnostic biomarkers for HBV-LF. These analyses and receive operating characteristic curves identified the genes for phosphatidic acid phosphatase type 2C (PPAP2C) and versican (VCAN) as potentially valuable diagnostic biomarkers for HBV-LF. Single-sample gene set enrichment analysis (ssGSEA) further confirmed the immune landscape of HBV-LF. The two diagnostic biomarkers also significantly correlated with infiltrating immune cells. The potential regulatory mechanisms of VCAN underlying the occurrence and development of HBV-LF were also analyzed. These collective findings implicate VCAN as a novel diagnostic biomarker for HBV-LF, and infiltration of immune cells may critically contribute to the occurrence and development of HBV-LF.

Mesenchymal stromal cells: promising treatment for liver cirrhosis.

Liver fibrosis is a wound-healing process that occurs in response to severe injuries and is hallmarked by the excessive accumulation of extracellular matrix or scar tissues within the liver. Liver fibrosis can be either acute or chronic and is induced by a variety of hepatotoxic causes, including lipid deposition, drugs, viruses, and autoimmune reactions. In advanced fibrosis, liver cirrhosis develops, a condition for which there is no successful therapy other than liver transplantation. Although liver transplantation is still a viable option, numerous limitations limit its application, including a lack of donor organs, immune rejection, and postoperative complications. As a result, there is an immediate need for a different kind of therapeutic approach. Recent research has shown that the administration of mesenchymal stromal cells (MSCs) is an attractive treatment modality for repairing liver injury and enhancing liver regeneration. This is accomplished through the cell migration into liver sites, immunoregulation, hepatogenic differentiation, as well as paracrine mechanisms. MSCs can also release a huge variety of molecules into the extracellular environment. These molecules, which include extracellular vesicles, lipids, free nucleic acids, and soluble proteins, exert crucial roles in repairing damaged tissue. In this review, we summarize the characteristics of MSCs, representative clinical study data, and the potential mechanisms of MSCs-based strategies for attenuating liver cirrhosis. Additionally, we examine the processes that are involved in the MSCs-dependent modulation of the immune milieu in liver cirrhosis. As a result, our findings lend credence to the concept of developing a cell therapy treatment for liver cirrhosis that is premised on MSCs. MSCs can be used as a candidate therapeutic agent to lengthen the survival duration of patients with liver cirrhosis or possibly reverse the condition in the near future.