The Inside-Out of End-Stage Liver Disease: Hepatocytes are the Keystone

Liver at crossroads: unraveling the links between obesity, chronic liver diseases, and the mysterious obesity paradox

Obesity is a global health issue that is intricately linked to the development and progression of chronic liver disease (CLD). This bidirectional connection, coupled with the obesity paradox (OP), presents a management dilemma. The established influence of obesity on the development and progression of chronic liver disease (CLD) is surpassed by the liver's impact on the onset and advancement of obesity. Patients with CLD always experience increased energy expenditure, reduced appetite, and low protein synthesis, all of which might lead to weight loss. However, metabolic disturbances, hormonal imbalances, inflammatory signaling, immobility, drugs, and alterations in nutrient metabolism can contribute to the development and exacerbation of obesity. Despite the propagation of the OP concept, none of the guidelines has changed, recommending being overweight. Research bias and confounders might be the lifebuoy explanation. Additionally, overlooking the lethal morbidities of obesity for survival benefits full of suffering seems to be an illogical idea. Therefore, rather than endorsing an overweight status, emphasis should be placed on improving cardiorespiratory fitness and preventing sarcopenia to achieve better outcomes in patients with CLD. Accordingly, the complex interplay between obesity, CLD, and the concept of OP requires a sophisticated individualized management approach. Maximizing cardiorespiratory fitness and mitigating sarcopenia should be considered essential strategies for attaining the most favourable outcomes in patients with chronic liver disease (CLD).

Contrast-enhanced ultrasound appearance of adrenal hemorrhage after orthotopic liver transplantation: a retrospective study

OBJECTIVES

This study aimed to identify the incidence of adrenal hemorrhage (AH) after OLT and to summarize the ultrasound (US) and contrast-enhanced ultrasound (CEUS) characteristics.

METHODS

Patients with adrenal lesions after OLT at our hospital were retrospectively reviewed between January 2010 and November 2023. The reference diagnosis was defined on the basis of surgical data, computed tomography scans, and magnetic resonance imaging with at least 12 months of follow-up. The incidence of AH and the US and CEUS characteristics after OLT were analyzed and compared with those of adrenal metastases.

RESULTS

A total of 23 patients (1.2%) with AH and 7 patients (0.35%) with suprarenal metastases were assessed. Compared with metastases, hematomas had more inhomogeneous echotextures (57% vs. 0.00%, P = 0.010), hypoechoic or mixed-echoic patterns (96% vs. 71%, P = 0.022), and anechoic areas (52% vs. 0.00%, P = 0.024), and their echotextures varied more over time (65% vs. 0.14%, P = 0.031). CEUS was performed on 12 patients with AH and 2 patients with metastases. A "jet-like" contrast superflux was observed in one actively bleeding hematoma, whereas no enhancement was observed in any static hematoma (100%). However, adrenal metastases had a contrast-enhanced appearance in the early arterial phase, followed by fast washout in the late phase (100%), and the difference was statistically significant (P < 0.001).

CONCLUSION

The sonographic characteristics of AH after OLT vary over time. CEUS is recommended when adrenal lesions are detected, as CEUS can differentiate AH from metastases.

Etiology-Specific Effects of Impaired Functional Status on Liver Transplant Outcomes

BACKGROUND AND AIMS

Pre-liver transplant (LT) functional status is an important determinant of prognosis post LT. There is insufficient data on how functional status affects outcomes of transplant recipients based on the specific etiology of liver disease. We stratified LT recipients by etiology of liver disease to evaluate the effects of functional status on post-LT prognosis in each subgroup.

METHODS

2005-2019 United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) was used to select patients with liver transplant. A total of 14,290 patients were included in the analysis. These patients were stratified by functional status according to Karnofsky Performance Scale (KPS) score: no assistance, some assistance, or total assistance. They were then further divided into six diagnosis categories: metabolic dysfunction-associated steatotic liver disease (MASLD), hereditary disorders, hepatitis C, hepatitis B, autoimmune disease (AID), and alcoholic liver disease (ALD). Primary endpoints included all-cause mortality and graft failure, while secondary endpoints included organ-specific causes of death. Those under the age of 18 and those with non-whole liver or prior liver transplantation were excluded.

RESULTS

Patients with MASLD requiring some assistance (aHR: 1.57, 95% CI 1.03-2.39, p = 0.04) and those requiring total assistance (aHR: 2.32, 95% CI 1.48-3.64, p < 0.001) had higher incidences of graft failure compared to those requiring no assistance. Those with MASLD requiring total assistance had a higher all-cause mortality rate than those needing no assistance (aHR: 1.62, 95% CI 1.38-1.89, p < 0.001). Patients with hereditary causes of liver disease showed a lower incidence of all-cause mortality in recipients needing some assistance compared with those needing no assistance (aHR: 0.52, 95% CI 0.34-0.80, p = 0.003). LT recipients with hepatitis C, AID, and ALD all showed higher incidences of all-cause mortality in the total assistance cohort when compared to the no assistance cohort. For the secondary endpoints of specific cause of death, transplant recipients with MASLD needing total assistance had higher rates of death due to general cardiac causes, graft rejection, general infectious causes, sepsis, general renal causes, and general respiratory causes.

CONCLUSION

Patients with MASLD cirrhosis demonstrated the worst overall outcomes, suggesting that this population may be particularly vulnerable. Poor functional status in patients with end-stage liver disease from hepatitis B or hereditary disease was not associated with a significantly increased rate of adverse outcomes, suggesting that the KPS score may not be broadly applicable to all patients awaiting LT.

Decellularised extracellular matrix-based injectable hydrogels for tissue engineering applications

Decellularised extracellular matrix (dECM) is a biomaterial derived from natural tissues that has attracted considerable attention from tissue engineering researchers due to its exceptional biocompatibility and malleability attributes. These advantageous properties often facilitate natural cell infiltration and tissue reconstruction for regenerative medicine. Due to their excellent fluidity, the injectable hydrogels can be administered in a liquid state and subsequently formed into a gel state in vivo, stabilising the target area and serving in a variety of ways, such as support, repair, and drug release functions. Thus, dECM-based injectable hydrogels have broad prospects for application in complex organ structures and various tissue injury models. This review focuses on exploring research advances in dECM-based injectable hydrogels, primarily focusing on the applications and prospects of dECM hydrogels in tissue engineering. Initially, the recent developments of the dECM-based injectable hydrogels are explained, summarising the different preparation methods with the evaluation of injectable hydrogel properties. Furthermore, some specific examples of the applicability of dECM-based injectable hydrogels are presented. Finally, we summarise the article with interesting prospects and challenges of dECM-based injectable hydrogels, providing insights into the development of these composites in tissue engineering and regenerative medicine.

Beyond the Diagnosis: A Deep Dive Into the End Stage Liver Disease Experience From the Patient Perspective

INTRODUCTION

End-stage liver disease (ESLD) presents a multifaceted challenge that encompasses not only physical but also emotional, psychological, and social dimensions. This study aims to explore the experiences of ESLD patients within the United States healthcare system.

METHODS

Utilizing a convenience sampling methodology, 15 ESLD patients from a tertiary care hospital in the USA participated in semi-structured interviews between April 2023 and January 2024. Data analysis was conducted using MAXQDA 2023, employing a phenomenological approach to identify common themes.

RESULTS

The study identified six primary themes: the significance of communication style in diagnosis delivery, the crucial role of family and social support, varied understanding and preferences for palliative care, diverse attitudes towards advanced care planning, preferences for coordinated healthcare experiences, and the emotional and psychological impact of ESLD.

CONCLUSION

Our study underscores the complexity of ESLD patient care beyond medical treatment, highlighting the importance of clear communication, empathetic care, and the integration of family and palliative care services.

Contemporary Insights into Hepatitis C Virus: A Comprehensive Review

Hepatitis C virus (HCV) remains a significant global health challenge. Approximately 50 million people were living with chronic hepatitis C based on the World Health Organization as of 2024, contributing extensively to global morbidity and mortality. The advent and approval of several direct-acting antiviral (DAA) regimens significantly improved HCV treatment, offering potentially high rates of cure for chronic hepatitis C. However, the promising aim of eventual HCV eradication remains challenging. Key challenges include the variability in DAA access across different regions, slightly variable response rates to DAAs across diverse patient populations and HCV genotypes/subtypes, and the emergence of resistance-associated substitutions (RASs), potentially conferring resistance to DAAs. Therefore, periodic reassessment of current HCV knowledge is needed. An up-to-date review on HCV is also necessitated based on the observed shifts in HCV epidemiological trends, continuous development and approval of therapeutic strategies, and changes in public health policies. Thus, the current comprehensive review aimed to integrate the latest knowledge on the epidemiology, pathophysiology, diagnostic approaches, treatment options and preventive strategies for HCV, with a particular focus on the current challenges associated with RASs and ongoing efforts in vaccine development. This review sought to provide healthcare professionals, researchers, and policymakers with the necessary insights to address the HCV burden more effectively. We aimed to highlight the progress made in managing and preventing HCV infection and to highlight the persistent barriers challenging the prevention of HCV infection. The overarching goal was to align with global health objectives towards reducing the burden of chronic hepatitis, aiming for its eventual elimination as a public health threat by 2030.

Human Hepatocellular response in Cholestatic Liver Diseases

Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), the most common types of cholestatic liver disease (CLD), result in enterohepatic obstruction, bile acid accumulation, and hepatotoxicity. The mechanisms by which hepatocytes respond to and cope with CLD remain largely unexplored. This study includes the characterization of hepatocytes isolated from explanted livers of patients with PBC and PSC. We examined the expression of hepatocyte-specific genes, intracellular bile acid (BA) levels, and oxidative stress in primary-human-hepatocytes (PHHs) isolated from explanted livers of patients with PBC and PSC and compared them with control normal human hepatocytes. Our findings provide valuable initial insights into the hepatocellular response to cholestasis in CLD and help support the use of PHHs as an experimental tool for these diseases.

KLF6 alleviates hepatic ischemia-reperfusion injury by inhibiting autophagy

Hepatic ischemia-reperfusion (I/R) injury, a common clinical complication of liver transplantation, gravely affects patient prognosis. Krüppel-like factors (KLFs) constitute a family of C2/H2 zinc finger DNA-binding proteins. KLF6, a member of the KLF protein family, plays crucial roles in proliferation, metabolism, inflammation, and injury responses; however, its role in HIR is largely remains unknown. After I/R injury, we found that KLF6 expression in mice and hepatocytes was significantly upregulated. Mice were then subjected to I/R following injection of shKLF6- and KLF6-overexpressing adenovirus through the tail vein. KLF6 deficiency markedly exacerbated liver damage, cell apoptosis, and activation of hepatic inflammatory responses, whereas hepatic overexpression of KLF6 in mice produced the opposite results. In addition, we knocked out or overexpressed KLF6 in AML12 cells before exposing them to a hypoxia-reoxygenation challenge. KLF6 knockout decreased cell viability and increased hepatocyte inflammation, apoptosis, and ROS, whereas KLF6 overexpression had the opposite effects. Mechanistically, KLF6 inhibited the overactivation of autophagy at the initial stage, and the regulatory effect of KLF6 on I/R injury was autophagy-dependent. CHIP-qPCR and luciferase reporter gene assays confirmed that KLF6 bound to the promoter region of Beclin1 and inhibited its transcription. Additionally, KLF6 activated the mTOR/ULK1 pathway. Finally, we performed a retrospective analysis of the clinical data of liver transplantation patients and identified significant associations between KLF6 expression and liver function following liver transplantation. In conclusion, KLF6 inhibited the overactivation of autophagy via transcriptional regulation of Beclin1 and activation of the mTOR/ULK1 pathway, thereby protecting the liver from I/R injury. KLF6 is expected to serve as a biomarker for estimating the severity of I/R injury following liver transplantation.

Branched Chain Amino Acids Are Associated with Physical Performance in Patients with End-Stage Liver Disease

Decreased circulating branched chain amino acids (BCAA) represent a prominent change in amino acid profiles in patients with end-stage liver disease (ESLD). These alterations are considered to contribute to sarcopenia and hepatic encephalopathy and may relate to poor prognosis. Here, we cross-sectionally analyzed the association between plasma BCAA levels and the severity of ESLD and muscle function in participants of the liver transplant subgroup of TransplantLines, enrolled between January 2017 and January 2020. Plasma BCAA levels were measured by nuclear magnetic resonance spectroscopy. Physical performance was analyzed with a hand grip strength test, 4 m walking test, sit-to-stand test, timed up and go test, standing balance test and clinical frailty scale. We included 92 patients (65% men). The Child Pugh Turcotte classification was significantly higher in the lowest sex-stratified BCAA tertile compared to the highest tertile (p = 0.015). The times for the sit-to-stand (r = -0.352, p < 0.05) and timed up and go tests (r = -0.472, p < 0.01) were inversely correlated with total BCAA levels. In conclusion, lower circulating BCAA are associated with the severity of liver disease and impaired muscle function. This suggests that BCAA may represent a useful prognostic marker in the staging of liver disease severity.

Loss of liver function in chronic liver disease: An identity crisis

Adult hepatocyte identity is constructed throughout embryonic development and fine-tuned after birth. A multinodular network of transcription factors, along with pre-mRNA splicing regulators, define the transcriptome, which encodes the proteins needed to perform the complex metabolic and secretory functions of the mature liver. Transient hepatocellular dedifferentiation can occur as part of the regenerative mechanisms triggered in response to acute liver injury. However, persistent downregulation of key identity genes is now accepted as a strong determinant of organ dysfunction in chronic liver disease, a major global health burden. Therefore, the identification of core transcription factors and splicing regulators that preserve hepatocellular phenotype, and a thorough understanding of how these networks become disrupted in diseased hepatocytes, is of high clinical relevance. In this context, we review the key players in liver differentiation and discuss in detail critical factors, such as HNF4α, whose impairment mediates the breakdown of liver function. Moreover, we present compelling experimental evidence demonstrating that restoration of core transcription factor expression in a chronically injured liver can reset hepatocellular identity, improve function and ameliorate structural abnormalities. The possibility of correcting the phenotype of severely damaged and malfunctional livers may reveal new therapeutic opportunities for individuals with cirrhosis and advanced liver disease.

Analysis of Immune and Inflammatory Microenvironment Characteristics of Noncancer End-Stage Liver Disease

Chronic liver injury eventually progresses to cirrhosis and end-stage liver disease (ESLD), which are the leading causes of death in patients with liver disease worldwide. ESLD has a variety of etiologies and a complex pathogenesis. This study analyzed the characteristics of ESLD by studying the immune microenvironment and inflammatory microenvironment of ESLD caused by 4 noncancer diseases, including HBV-ALF, ALF, AILD, and AH. We collected transcriptome data from noncancer ESLD patients, collected liver tissue samples and blood samples from ESLD liver transplant patients, and analyzed the immune and inflammatory microenvironments in the liver and blood. The results showed that with the exception of HBV-induced ESLD, there were no significant differences in immune microenvironment scores among patients with ESLD caused by other noncancer diseases. Moreover, there were no significant differences in the inflammatory microenvironment in the liver and blood of patients with ESLD caused by the 4 noncancer diseases. Furthermore, we found that the cytokine, IL-15, could predict the prognosis of ESLD patients.

Biofabrication of synthetic human liver tissue with advanced programmable functions

Advances in cellular engineering, as well as gene, and cell therapy, may be used to produce human tissues with programmable genetically enhanced functions designed to model and/or treat specific diseases. Fabrication of synthetic human liver tissue with these programmable functions has not been described. By generating human iPSCs with target gene expression controlled by a guide RNA-directed CRISPR-Cas9 synergistic-activation-mediator, we produced synthetic human liver tissues with programmable functions. Such iPSCs were guide-RNA-treated to enhance expression of the clinically relevant CYP3A4 and UGT1A1 genes, and after hepatocyte-directed differentiation, cells demonstrated enhanced functions compared to those found in primary human hepatocytes. We then generated human liver tissue with these synthetic human iPSC-derived hepatocytes (iHeps) and other non-parenchymal cells demonstrating advanced programmable functions. Fabrication of synthetic human liver tissue with modifiable functional genetic programs may be a useful tool for drug discovery, investigating biology, and potentially creating bioengineered organs with specialized functions.

Therapeutic Potential of HNF4α in End-stage Liver Disease

The prevalence of end-stage liver disease (ESLD) in the US is increasing at an alarming rate. It can be caused by several factors; however, one of the most common routes begins with nonalcoholic fatty liver disease (NAFLD). ESLD is diagnosed by the presence of irreversible damage to the liver. Currently, the only definitive treatment for ESLD is orthotopic liver transplantation (OLT). Nevertheless, OLT is limited due to a shortage of donor livers. Several promising alternative treatment options are under investigation. Researchers have focused on the effect of liver-enriched transcription factors (LETFs) on disease progression. Specifically, hepatocyte nuclear factor 4-alpha (HNF4α) has been reported to reset the liver transcription network and possibly play a role in the regression of fibrosis and cirrhosis. In this review, we describe the function of HNF4α, along with its regulation at various levels. In addition, we summarize the role of HNF4α in ESLD and its potential as a therapeutic target in the treatment of ESLD.