Genetic landscape and immune mechanism of monocytes associated with the progression of acute-on-chronic liver failure

Evaluation of the expression of fibrosis-related genes as non-invasive diagnostic biomarkers for cirrhotic HCV-infected patients

Liver cirrhosis is a condition with high mortality that poses a significant health and economic burden worldwide. The clinical characteristics of liver cirrhosis are complex and varied. Therefore, the evaluation of immune infiltration-involved genes incirrhosis has become mandatory in liver disease research, not only to identify the potential biomarkers but also to provide important insights into the underlying mechanisms of the disease. In this study, we aimed to investigate the expression profile of cytokine genes in peripheral blood mononuclear cells (PBMCs) of HCV patients and identify the gene expression signature associated with advanced cirrhosis. A cross-sectional study of 90 HCV genotype 4 patients, including no fibrosis patients (F0, n = 24), fibrotic patients (F1-F3, n = 36), and cirrhotic patients (F4, n = 30) has been conducted. The expression of cytokine genes was analyzed by quantitative real-time PCR in the subjects' PBMCs, and the serum level of TGFβ2 was measured by ELISA. Our findings showed that the expression level of the TGIF1 transcript was lower in cirrhotic and fibrotic patients compared to no fibrosis patients (p = 0.046 and 0.022, respectively). Also, there was an upregulation of the TGFβ1 gene in cirrhotic patients relative to fibrotic patients (p = 0.015). Additionally, the cirrhotic patients had higher expression levels of the TGF-β2 transcript and elevated levels of the TGF-β2 protein than patients with no cirrhosis or fibrosis. According to the ROC analysis, TGFβ1, TGIF1 transcripts, and TGFβ2 protein have a good discriminatory performance in distinguishing between cirrhotic, fibrotic, and non-fibrotic patients. Our results suggested that the expression of TGIF1, TGF-β1, and TGF-β2 genes in PBMCs may provide a valuable tool for identifying patients with advanced cirrhosis and that TGF-β and TGIF1 may be potential biomarkers for cirrhosis. These findings may have implications for the diagnosis and treatment of cirrhosis in HCV patients.

Hematological ratios in patients with acute decompensation and acute-on-chronic liver failure: prognostic factors

BACKGROUND AND AIMS

Acute-on-chronic liver failure (ACLF) is the most severe form of acutely decompensated cirrhosis and is characterized by the presence of intense systemic inflammation. Leucocyte quantification can serve as an indirect indicator of systemic inflammation. In our study, we investigated the predictive value of hematological ratios (neutrophils to lymphocytes, monocyte to lymphocytes, platelets to lymphocytes, lymphocytes to C-reactive protein, and neutrophils to lymphocytes and platelets) in acute decompensation (AD) and ACLF patients and their relation to disease severity and early mortality.

PATIENTS AND METHODS

We included 60 patients with ACLF and AD, and 30 cirrhotic controls. Clinical data were collected, and survival was followed for 1 and 6 months. Blood samples were analyzed at admission for differential leucocytes and assessed for liver and renal function tests. The leukocyte ratios were calculated and compared, and their correlation with liver function indicators and prognosis was assessed.

RESULTS

All ratios were significantly higher in AD and ACLF patients compared to control (except for lymphocyte to C-reactive protein ratio which was significantly lower), and were positively correlated with Child-Pugh score, model for end-stage liver disease (MELD)-Na, and ACLF severity scores. Multivariate regression revealed that neutrophil to lymphocyte ratio, monocyte to lymphocyte ratio, and MELD-Na were independent prognostic factors of 1-month and 6-month mortality. A unique prognostic nomogram incorporating MELD-Na, neutrophil to lymphocyte ratio, and monocyte to lymphocyte ratio could be proposed for predicting prognosis in AD and ACLF patients.

CONCLUSIONS

Cheap, easy, and noninvasive hematological ratios are introduced as a tool for early identification and risk stratification of AD and ACLF patients.

Approaching Thrombospondin-1 as a Potential Target for Mesenchymal Stromal Cells to Support Liver Regeneration after Partial Hepatectomy in Mouse and Humans

Extended liver resection carries the risk of post-surgery liver failure involving thrombospondin-1-mediated aggravation of hepatic epithelial plasticity and function. Mesenchymal stromal cells (MSCs), by interfering with thrombospondin-1 (THBS1), counteract hepatic dysfunction, though the mechanisms involved remain unknown. Herein, two-thirds partial hepatectomy in mice increased hepatic THBS1, downstream transforming growth factor-β3, and perturbation of liver tissue homeostasis. All these events were ameliorated by hepatic transfusion of human bone marrow-derived MSCs. Treatment attenuated platelet and macrophage recruitment to the liver, both major sources of THBS1. By mitigating THBS1, MSCs muted surgery-induced tissue deterioration and dysfunction, and thus supported post-hepatectomy regeneration. After liver surgery, patients displayed increased tissue THBS1, which is associated with functional impairment and may indicate a higher risk of post-surgery complications. Since liver dysfunction involving THBS1 improves with MSC treatment in various animal models, it seems feasible to also modulate THBS1 in humans to impede post-surgery acute liver failure.

Thrombospondin 1 enhances systemic inflammation and disease severity in acute-on-chronic liver failure

BACKGROUND

The key role of thrombospondin 1 (THBS1) in the pathogenesis of acute-on-chronic liver failure (ACLF) is unclear. Here, we present a transcriptome approach to evaluate THBS1 as a potential biomarker in ACLF disease pathogenesis.

METHODS

Biobanked peripheral blood mononuclear cells (PBMCs) from 330 subjects with hepatitis B virus (HBV)-related etiologies, including HBV-ACLF, liver cirrhosis (LC), and chronic hepatitis B (CHB), and normal controls (NC) randomly selected from the Chinese Group on the Study of Severe Hepatitis B (COSSH) prospective multicenter cohort underwent transcriptome analyses (ACLF = 20; LC = 10; CHB = 10; NC = 15); the findings were externally validated in participants from COSSH cohort, an ACLF rat model and hepatocyte-specific THBS1 knockout mice.

RESULTS

THBS1 was the top significantly differentially expressed gene in the PBMC transcriptome, with the most significant upregulation in ACLF, and quantitative polymerase chain reaction (ACLF = 110; LC = 60; CHB = 60; NC = 45) was used to verify that THBS1 expression corresponded to ACLF disease severity outcome, including inflammation and hepatocellular apoptosis. THBS1 showed good predictive ability for ACLF short-term mortality, with an area under the receiver operating characteristic curve (AUROC) of 0.8438 and 0.7778 at 28 and 90 days, respectively. Enzyme-linked immunosorbent assay validation of the plasma THBS1 using an expanded COSSH cohort subjects (ACLF = 198; LC = 50; CHB = 50; NC = 50) showed significant correlation between THBS1 with ALT and γ-GT (P = 0.01), and offered a similarly good prognostication predictive ability (AUROC = 0.7445 and 0.7175) at 28 and 90 days, respectively. ACLF patients with high-risk short-term mortality were identified based on plasma THBS1 optimal cut-off value (< 28 µg/ml). External validation in ACLF rat serum and livers confirmed the functional association between THBS1, the immune response and hepatocellular apoptosis. Hepatocyte-specific THBS1 knockout improved mouse survival, significantly repressed major inflammatory cytokines, enhanced the expression of several anti-inflammatory mediators and impeded hepatocellular apoptosis.

CONCLUSIONS

THBS1 might be an ACLF disease development-related biomarker, promoting inflammatory responses and hepatocellular apoptosis, that could provide clinicians with a new molecular target for improving diagnostic and therapeutic strategies.

Single-cell Technologies Provide Novel Insights into Liver Physiology and Pathology

The liver is the largest glandular organ in the body and has a unique distribution of cells and biomolecules. However, the treatment outcome of end-stage liver disease is extremely poor. Single-cell sequencing is a new advanced and powerful technique for identifying rare cell populations and biomolecules by analyzing the characteristics of gene expression between individual cells. These cells and biomolecules might be used as potential targets for immunotherapy of liver diseases and contribute to the development of precise individualized treatment. Compared to whole-tissue RNA sequencing, single-cell RNA sequencing (scRNA-seq) or other single-cell histological techniques have solved the problem of cell population heterogeneity and characterize molecular changes associated with liver diseases with higher accuracy and resolution. In this review, we comprehensively summarized single-cell approaches including transcriptomic, spatial transcriptomic, immunomic, proteomic, epigenomic, and multiomic technologies, and described their application in liver physiology and pathology. We also discussed advanced techniques and recent studies in the field of single-cell; our review might provide new insights into the pathophysiological mechanisms of the liver to achieve precise and individualized treatment of liver diseases.