Balance between macrophage migration inhibitory factor and sCD74 predicts outcome in patients with acute decompensation of cirrhosis

The Role of Macrophage Inhibitory Factor in TAA-Induced Liver Fibrosis in Mice: Modulatory Effects of Betaine

Macrophage inhibitory factor (MIF) is a multipotent cytokine, involved in the inflammatory response to infections or injuries. This study investigates the role of MIF in liver fibrosis and the modulating effect of betaine on MIF in thioacetamide (TAA)-induced liver fibrosis. The wild-type and knockout MIF-/- C57BL/6 mice were divided into the following groups: control; Bet group, which received betaine; MIF-/-; MIF-/-+Bet; TAA group, which received TAA; TAA+Bet; MIF-/-+TAA; and MIF-/-+TAA+Bet group. After eight weeks of treatment, liver tissue was collected for further analysis. The results revealed that TAA-treated MIF-deficient mice had elevated levels of hepatic TGF-β1 and PDGF-BB, as well as MMP-2, MMP-9, and TIMP-1 compared to TAA-treated wild-type mice. However, the administration of betaine to TAA-treated MIF-deficient mice reduced hepatic TGF-β1 and PDGF-BB levels and also the relative activities of MMP-2, MMP-9 and TIMP-1, albeit less effectively than in TAA-treated mice without MIF deficiency. Furthermore, the antifibrogenic effect of MIF was demonstrated by an increase in MMP2/TIMP1 and MMP9/TIMP1 ratios. The changes in the hepatic levels of fibrogenic factors were confirmed by a histological examination of liver tissue. Overall, the dual nature of MIF highlights its involvement in the progression of liver fibrosis. Its prooxidant and proinflammatory effects may exacerbate tissue damage and inflammation initially, but its antifibrogenic activity suggests a potential protective role against fibrosis development. The study showed that betaine modulates the antifibrogenic effects of MIF in TAA-induced liver fibrosis, by decreasing TGF-β1, PDGF-BB, MMP-2, MMP-9, TIMP-1, and the deposition of ECM (Coll1 and Coll3) in the liver.

Soluble urokinase plasminogen activator receptor levels predict survival in patients with portal hypertension undergoing TIPS

Background & Aims

Transjugular intrahepatic portosystemic shunt (TIPS) is the most effective therapy for complications of portal hypertension. However, clinical outcomes following TIPS placement vary widely between patients and identifying ideal candidates remains a challenge. Soluble urokinase plasminogen activator receptor (suPAR) is a circulating marker of immune activation that has previously been associated with liver inflammation, but its prognostic value in patients receiving TIPS is unknown. In the present study, we evaluated the potential clinical relevance of suPAR levels in patients undergoing TIPS insertion.

Methods

suPAR concentrations were measured by ELISA in hepatic vein (HV) and portal vein (PV) blood samples from 99 patients (training cohort) as well as peripheral venous blood samples from an additional 150 patients (validation cohort) undergoing TIPS placement. The association between suPAR levels and patient outcomes was assessed using Kaplan-Meier methods and Cox-regression analyses.

Results

suPAR concentrations were significantly higher in HV samples compared to PV samples and correlated with PV concentration, the presence of ascites, renal injury, and consequently with the Child-Pugh and MELD scores. Patients with lower suPAR levels had significantly better short- and long-term survival after TIPS insertion, which remained robust after adjustment for confounders in multivariate Cox-regression analyses. Sensitivity analysis showed an improvement in risk prediction in patients stratified by Child-Pugh or MELD scores. In an independent validation cohort, higher levels of suPAR predicted poor transplant-free survival after TIPS, particularly in patients with Child-Pugh A/B cirrhosis.

Conclusion

suPAR is largely derived from the injured liver and its levels are predictive of outcome in patients undergoing TIPS. suPAR, as a surrogate of hepatic inflammation, may be used to stratify care in patients following TIPS insertion.

Impact and implications

Transjugular intrahepatic portosystemic shunt (TIPS) is the most effective therapy for complications of portal hypertension. However, clinical outcomes following TIPS placement vary widely between patients and identification of the ideal candidates remains challenging. We show that soluble urokinase plasminogen activator receptor (suPAR), a circulating marker of immune activation that can easily be measured in routine clinical practice, is a novel marker to identify patients who will benefit from TIPS and those who will not.

Liver-restricted Type I IFN Signature Precedes Liver Damage in Chronic Hepatitis B Patients Stopping Antiviral Therapy

Immune-mediated liver damage is the driver of disease progression in patients with chronic hepatitis B virus (HBV) infection. Liver damage is an Ag-independent process caused by bystander activation of CD8 T cells and NK cells. How bystander lymphocyte activation is initiated in chronic hepatitis B patients remains unclear. Periods of liver damage, called hepatic flares, occur unpredictably, making early events difficult to capture. To address this obstacle, we longitudinally sampled the liver of chronic hepatitis B patients stopping antiviral therapy and analyzed immune composition and activation using flow cytometry and single-cell RNA sequencing. At 4 wk after stopping therapy, HBV replication rebounded but no liver damage was detectable. There were no changes in cell frequencies at viral rebound. Single-cell RNA sequencing revealed upregulation of IFN-stimulated genes (ISGs) and proinflammatory cytokine migration inhibitory factor (MIF) at viral rebound in patients that go on to develop hepatic flares 6-18 wk after stopping therapy. The type I IFN signature was only detectable within the liver, and neither IFN-α/β or ISG induction could be detected in the peripheral blood. In vitro experiments confirmed the type I IFN-dependent ISG profile whereas MIF was induced primarily by IL-12. MIF exposure further amplified inflammatory cytokine production by myeloid cells. Our data show that innate immune activation is detectable in the liver before clinically significant liver damage is evident. The combination of type I IFN and enhanced cytokine production upon MIF exposure represent the earliest immunological triggers of lymphocyte bystander activation observed in hepatic flares associated with chronic HBV infection.

Clinical determinants of hospital mortality in liver failure: a comprehensive analysis of 62,717 patients

BACKGROUND

Liver failure (LF) is characterised by a loss of the synthetic and metabolic liver function and is associated with a high mortality. Large-scale data on recent developments and hospital mortality of LF in Germany are missing. A systematic analysis and careful interpretation of these datasets could help to optimise outcomes of LF.

METHODS

We used standardised hospital discharge data of the Federal Statistical Office to evaluate current trends, hospital mortality and factors associated with an unfavourable course of LF in Germany between 2010 and 2019.

RESULTS

A total of 62,717 hospitalised LF cases were identified. Annual LF frequency decreased from 6716 (2010) to 5855 (2019) cases and was higher among males (60.51%). Hospital mortality was 38.08% and significantly declined over the observation period. Mortality significantly correlated with patients' age and was highest among individuals with (sub)acute LF (47.5%). Multivariate regression analyses revealed pulmonary (ORARDS: 2.76, ORmechanical ventilation: 6.46) and renal complications (ORacute kidney failure: 2.04, ORhepatorenal syndrome: 2.92) and sepsis (OR: 1.92) as factors for increased mortality. Liver transplantation reduced mortality in patients with (sub)acute LF. Hospital mortality significantly decreased with the annual LF case volume and ranged from 47.46% to 29.87% in low- or high-case-volume hospitals, respectively.

CONCLUSIONS

Although incidence rates and hospital mortality of LF in Germany have constantly decreased, hospital mortality has remained at a very high level. We identified a number of variables associated with increased mortality that could help to improve framework conditions for the treatment of LF in the future.

Macrophage migration inhibitory factor receptor CD74 expression is associated with expansion and differentiation of effector T cells in COVID-19 patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused millions of COVID-19 cases and deaths worldwide. Severity of pulmonary pathologies and poor prognosis were reported to be associated with the activation non-virus-specific bystander T cells. In addition, high concentrations of the macrophage migration inhibitory factor (MIF) were found in serum of COVID-19 patients. We hypothesized that these two pathogenic factors might be related and analyzed the expression of receptors for MIF on T cells in COVID-19. T cells from PBMCs of hospitalized patients with mild and severe COVID-19 were characterized. A significantly higher proportion of CD4+ and CD8+ T cells from COVID-19 patients expressed CD74 on the cell surface compared to healthy controls. To induce intracellular signaling upon MIF binding, CD74 forms complexes with CD44, CXCR2, or CXCR4. The vast majority of CD74+ T cells expressed CD44, whereas expression of CXCR2 and CXCR4 was low in controls but increased upon SARS-CoV-2 infection. Hence, T cells in COVID-19 patients express receptors that render them responsive to MIF. A detailed analysis of CD74+ T cell populations revealed that most of them had a central memory phenotype early in infection, while cells with an effector and effector memory phenotype arose later during infection. Furthermore, CD74+ T cells produced more cytotoxic molecules and proliferation markers. Our data provide new insights into the MIF receptor and co-receptor repertoire of bystander T cells in COVID-19 and uncovers a novel and potentially druggable aspect of the immunological footprint of SARS-CoV-2.

The Impact of Transjugular Intrahepatic Portosystemic Shunt on Nutrition in Liver Cirrhosis Patients: A Systematic Review

Background and Aims: Liver cirrhosis leads to clinically significant portal hypertension. Transjugular intrahepatic portosystemic shunt (TIPS) has been shown to effectively reduce the degree of portal hypertension and treat its complications. However, poor nutritional status has been shown to be associated with hepatic encephalopathy, acute on chronic liver failure, and mortality following TIPS placement. The purpose of this systematic review is to create another perspective and evaluate the effect of TIPS placement on the nutritional status of patients with liver cirrhosis. Methods: A comprehensive search of four major electronic databases was conducted to identify studies that assessed the nutritional status of cirrhotic patients before and after TIPS placement. The risk of bias was evaluated using ROBINS-I guidelines. Results: Fifteen studies were analyzed in this review. The results indicate that among the 11 studies that evaluated changes in ascites-free weight and body mass index or body cell mass, 10 reported an improvement in one or more measures. Furthermore, all seven studies that evaluated changes in muscle mass demonstrated an increase in muscle mass. Among the four studies that evaluated subcutaneous fat tissue, three showed a significant expansion, while two out of three studies evaluating visceral fat tissue reported a significant reduction. Conclusions: The results of this systematic review suggest that TIPS placement is associated with improvement in the nutritional status of cirrhotic patients, indicated by an increase in ascites-free weight, body mass index, and muscle mass. Additionally, TIPS placement leads to a shift in the distribution of fat mass, with a preference for subcutaneous over visceral adipose tissue. Notably, sarcopenic patients seem to benefit the most from TIPS placement in terms of nutritional status.

Biomarkers of hepatocellular synthesis in patients with decompensated cirrhosis

BACKGROUND AND AIM

Since hepatocytes produce majority of serum proteins, patients with cirrhosis display substantial alterations in the serum proteome. The aim of the current study was to characterize these changes and to study the prognostic utility of hepatocellular proteins available in routine clinical testing.

METHODS

Sera from 29 healthy controls and 43 patients with cirrhosis were subjected to untargeted proteomic analysis. Unsupervised hierarchical clustering was performed with Perseus software and R. Ingenuity pathway analysis (IPA) suggested upstream regulators that were validated in liver tissues. The behavior and prognostic usefulness of selected biomarkers was investigated in 61 controls and 285 subjects with decompensated cirrhosis.

RESULTS

Proteomics uncovered 65 and 16 hepatocellular serum proteins that are significantly downregulated or upregulated in patients with cirrhosis vs. controls. Hierarchical clustering revealed two main clusters and six sub-clusters. IPA identified HNF4α and IL-6 as the two major upstream regulators that were confirmed by hepatic gene expression analyses. Among pseudocholinesterase, transferrin, transthyretin, albumin, and apolipoprotein AI (Apo-AI), Apo-AI was the best predictor of 90-days transplant-free survival (AUROC 0.678; p = 0.0001) and remained an independent predictor in multivariable Cox independently of the presence of acute-on-chronic liver failure.

CONCLUSION

Our study reveals cirrhosis-associated changes in hepatocellular serum proteins and underlying transcription factors. Serum apolipoprotein AI may constitute a useful prognostic adjunct in patients with decompensated cirrhosis.

Expression and Correlation of MIF and ERK1/2 in Liver Cirrhosis and Hepatocellular Carcinoma Induced by Hepatitis B

Objective

To detect expression and phosphorylation level of macrophage migration inhibitor (MIF) and extracellular-regulated kinases 1 and 2 (ERK1/2) in hepatitis B-induced liver cirrhosis (HBILC) and hepatocellular carcinoma (HCC) with a background of HBILC and analyze the correlation of MIF and ERK1/2 with HBILC and HCC.

Methods

Twenty cases of normal liver tissues were collected as a control group, and 48 specimens of HBILC tissues and 48 specimens of HCC tissues were collected as the experimental group, which were assigned as the HBILC group and HCC group, respectively. All tissue specimens were processed into tissue chips. The expressions of MIF, ERK1/2, and their phosphorylated proteins were detected via immunohistochemistry, and MIF and ERK1/2 nucleic acid expressions were detected by in situ hybridization. The results were statistically analyzed using the chi-square test.

Results

Proteins and nucleic acids of MIF and ERK1/2 presented low expression in the control group and high expression in the HBILC group and HCC group. MIF expression in the three groups was 25.0%, 75.0%, and 79.17%, respectively, while that of the nucleic acids was 25.0%, 70.83%, and 68.75%, respectively. Expression of ERK1/2 in the three groups was 40.0%, 60.42%, and 81.25%, respectively, and that of nucleic acids was 40.0%, 79.17%, and 77.08%. Expression of pERK1/2 was low in the control and HBILC group and high in the HCC group. Expression of pERK1/2 in the three groups was 20%, 45.83%, and 75%, respectively. Expression of pERK1/2 in the HCC group was significantly different from that in the HBILC and control group (P<0.05), but the difference between the HBILC group and control group was not statistically significant (P>0.05).

Conclusion

Occurrence and development of HBILC and HCC are not only related to the high expression of MIF but also closely related to the activation of the ERK1/2 signaling pathway.

D-dopachrome tautomerase in cardiovascular and inflammatory diseases-A new kid on the block or just another MIF?

Macrophage migration inhibitory factor (MIF) as well as its more recently described structural homolog D-dopachrome tautomerase (D-DT), now also termed MIF-2, are atypical cytokines and chemokines with key roles in host immunity. They also have an important pathogenic role in acute and chronic inflammatory conditions, cardiovascular diseases, lung diseases, adipose tissue inflammation, and cancer. Although our mechanistic understanding of MIF-2 is relatively limited compared to the extensive body of evidence available for MIF, emerging data suggests that MIF-2 is not only a functional phenocopy of MIF, but may have differential or even oppositional activities, depending on the disease and context. In this review, we summarize and discuss the similarities and differences between MIF and MIF-2, with a focus on their structures, receptors, signaling pathways, and their roles in diseases. While mainly covering the roles of the MIF homologs in cardiovascular, inflammatory, autoimmune, and metabolic diseases, we also discuss their involvement in cancer, sepsis, and chronic obstructive lung disease (COPD). A particular emphasis is laid upon potential mechanistic explanations for synergistic or cooperative activities of the MIF homologs in cancer, myocardial diseases, and COPD as opposed to emerging disparate or antagonistic activities in adipose tissue inflammation, metabolic diseases, and atherosclerosis. Lastly, we discuss potential future opportunities of jointly targeting MIF and MIF-2 in certain diseases, whereas precision targeting of only one homolog might be preferable in other conditions. Together, this article provides an update of the mechanisms and future therapeutic avenues of human MIF proteins with a focus on their emerging, surprisingly disparate activities, suggesting that MIF-2 displays a variety of activities that are distinct from those of MIF.