Livers, Volume 2, Issue 4 (December 2022) – 13 articles

Acetaminophen (APAP) is a widely used pain reliever that can cause liver injury or liver failure in response to an overdose. Understanding the mechanisms of APAP-induced cell death is critical for identifying new therapeutic targets. In this respect it was hypothesized that hepatocytes die by oncotic necrosis, apoptosis, necroptosis, ferroptosis and more recently pyroptosis. The latter cell death is characterized by caspase-dependent gasdermin cleavage into a C-terminal and an N-terminal fragment, which forms pores in the plasma membrane. The gasdermin pores can release potassium, interleukin-1β (IL-1β), IL-18, and other small molecules in a sublytic phase, which can be the main function of the pores in certain cell types such as inflammatory cells. Alternatively, the process can progress to full lysis of the cell (pyroptosis) with extensive cell contents release. This review discusses the experimental evidence for the involvement of pyroptosis in APAP hepatotoxicity as well as the arguments against pyroptosis as a relevant mechanism of APAP-induced cell death in hepatocytes. Based on the critical evaluation of the currently available literature and understanding of the pathophysiology, it can be concluded that pyroptotic cell death is unlikely to be a relevant contributor to APAP-induced liver injury. Full article

Despite the high medical and socioeconomic burden of non-alcoholic fatty liver disease (NAFLD), treatments that could effectively reduce histological liver damage in this condition are lacking. As providing only qualitative data is a major limitation of most histological scoring systems, we aimed to develop a simple and straightforward algorithm for semiquantitative analysis of scored histology data using the extended Fisher’s exact test in the R environment. As an illustrative example, we used the effects of L-ornithine L-aspartate (LOLA) and empagliflozin (EMPA) in a 3-month chemical/dietary murine model of NAFLD. 100 C57Bl/6 mice were randomized into 4 groups: Intact (n = 10), Control (NAFLD; n = 30), LOLA (NAFLD + 1.5 g·kg⁻¹ b.w./d LOLA orally; n = 30), and EMPA (NAFLD + 10 mg·kg⁻¹ b.w./d EMPA orally; n = 30). LOLA reduced hepatitis activity (p < 0.05), cholestasis, necrosis, and fibrosis severity (p < 0.01), and EMPA prevented necrosis (p < 0.05) and reduced fibrosis severity (p < 0.01). The statistical approach we suggest can be used as a simple complementary tool for exploratory analysis of scored histology data. Full article

Sesquiterpenoid tagitinin C, present in Tithonia diversifolia leaves, has been known to have anti-hepatoma properties. Therefore, we investigated the anti-metastatic potential of tagitinin C in xenograft models of hepatocellular carcinoma (HCC). We isolated tagitinin C from a methanolic extract of the leaves of T. diversifolia. HepG-2 and Huh 7 hepatoma cells were treated with tagitinin C, and cell viability, migration, and matrix metalloproteinase (MPP) activity were assessed using the 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide assay, scratch migration assay, and MMP activity assay, respectively. We used magnetic resonance spectroscopy to determine the tumorigenicity of xenografts inoculated with Hep-G2 and Huh 7 cells. Tagitinin C was cytotoxic against Hep-G2 and Huh 7 cells, with IC₅₀ values of 2.0 ± 0.1 µg/mL and 1.2 ± 0.1 µg/mL, respectively, and it showed an anti-metastatic effect in vitro. Additionally, MRS assays revealed that tagitinin C (15 g/mouse/day) reduced the tumorigenicity of Hep-G2 and Huh 7 cell xenografts. Tagitinin C demonstrated significant antitumor and anti-metastatic activity in the two human hepatoma cell lines. Tagitinin C might be used as an alternative or auxiliary therapy for the treatment of HCC, and its effect should be further investigated in clinical settings. Full article

The Spheroid Reservoir Bioartificial Liver (SRBAL) is an innovative treatment option for acute liver failure (ALF). This extracorporeal support device, which provides detoxification and other liver functions using high-density culture of porcine hepatocyte spheroids, has been reported in three randomized large animal studies. A meta-analysis of these three preclinical studies was performed to establish efficacy of SRBAL treatment in terms of survival benefit and neuroprotective effect. The studies included two hepatotoxic drug models of ALF (D-galactosamine, α-amanitin/lipopolysaccharide) or a liver resection model (85% hepatectomy) in pigs or monkeys. The SRBAL treatment was started in three different settings starting at 12 h, 24 h or 48 h after induction of ALF; comparisons were made with two similar control groups in each model. SRBAL therapy was associated with significant survival and neuroprotective benefits in all three animal models of ALF. The benefits of therapy were dose dependent with the most effective configuration of SRBAL being continuous treatment of 24 h duration and dose of 200 g of porcine hepatic spheroids. Future clinical testing of SRBAL in patients with ALF appears warranted. Full article

Chronic liver diseases (CLDs) that lead to hepatic fibrosis, cirrhosis, and/or hepatocellular carcinoma (HCC) have become a major cause of illness and death worldwide. The main causative factors for CLDs are chronic viral infections, excessive alcohol consumption, non-alcoholic fatty liver disease (NAFLD), and cholestatic diseases. The primary approach to managing cirrhosis should be removing the causative agent, and the secondary approach should address fibrogenesis. Liver cancer is also a leading cause of death worldwide, and many therapeutic approaches exist to treat the disease. However, liver transplantation remains the last treatment option for cirrhosis and liver cancer. Thus, this review discusses the pathophysiology of liver fibrosis, its progression to cirrhosis and HCC, and current therapeutic options available to treat the diseases with potential therapeutic options that will be available in the near future. Full article

FYB2 (also known as C1orf168 or ARAP) is an adaptor protein involved in T-cell receptor (TCR)-mediated T-cell activation and adhesion. However, the correlation of FYB2 with prognosis and cancer needs further investigation. In this study, we analyzed the expression levels of FYB2 in hepatocellular carcinoma (LIHC) tumor tissues and correlated it with the pathological stages, survival outcomes, and tumor grades. We found that the expression of FYB2 was significantly downregulated in LIHC. Low FYB2 level leading to weak survival outcomes is linked with advanced tumor grades and elevated pathological stages. Cox regression analysis showed that FYB2 and AJCC-M stages can be used as independent prognostic factors for LIHC. GSEA analysis revealed that FYB2 would be notably correlated with the cellular metabolism-related pathways and particularly involved in the regulation of cancer-related pathways. Single-cell transcriptome analysis revealed that FYB2-positive cells were mainly distributed in hepatocytes, and compared with other cells, the upregulated genes of these cells were mainly enriched in metabolism-related functions. The results of the spatial transcriptome revealed that the expression of FYB2 in the adjacent area was higher than in the tumor area. These results showed that FYB2 is likely to be a new prognostic biomarker in LIHC and would help provide individual treatment decisions for LIHC patients. Full article

Hepatocellular carcinoma (HCC) is the third major cause of cancer-related death worldwide and responds positively to tyrosine kinase inhibitors (TKIs). Dasatinib (Das) is an Src/Abl family kinase and has been successfully utilized in the treatment of various cancers. Cancer cells are known to limit their oxidative phosphorylation to minimize oxidative stress. Palmitoylcarnitine (Pcar) incubation triggers mitochondria-mediated apoptosis in cancer cells by increasing the mitochondrial respiration rate. It stimulates the H₂O₂ production in cancer cells and thus induces oxidative stress. Thus, considering the above observations, the combined effect of Pcar and Das on HepG2, liver cancer cells has been evaluated in the present study. Results demonstrated that combined exposure to Pcar and dasatinib inhibited cell growth, proliferation, and invasion efficiency of cancerous cells more than single-drug treatment. Further, cells undergo membrane depolarization and caspase-dependent apoptosis upon exposure to combined treatment. In addition, in vivo study showed that Pcar and dasatinib treatment reduced the tumor size in mice more significantly than single-drug treatment. Thus, considering the above remarks, combined therapy of Pcar and dasatinib may serve as a potential candidate in the treatment of liver cancer in human and animal tissues. Full article

(1) Background: The treatment goal of ketogenic glycogen storage diseases (GSDs) is appropriate control of hypoglycemia and other disturbances such as dyslipidemia. Monitoring and treatment of ketosis are known to improve outcomes. We used breath analysis to identify volatile organic compounds (VOCs) that correlate with serum ketones in order to provide a non-invasive method of monitoring ketosis. (2) Methods: Consecutive children with ketogenic GSDs were recruited from a single center during routine admission to monitor serum glucose and ketone levels. Five breath samples were collected from every patient at the same time of blood draws. SIFT-mass spectrometry was used to analyze breath samples. Univariate linear mixed-effects regression models for 22 known VOCs and either serum ketones or glucose were performed. (3) Results: Our cohort included 20 patients aged 5–15 years with a mean BMI of 20 kg/m² (72% tile). Most patients had GSD type 0 (35%), while 25% had type IX. VOCs that showed a significant correlation with serum ketone levels included acetone (p < 0.0001), trimethylamine (p < 0.0001), pentane (p = 0.0001), 3-methylhexane (p = 0.0047), and carbon disulfide (p = 0.0499). No correlation was found between serum glucose and any VOC. (4) Conclusions: Breath analysis is a promising noninvasive tool that can be used to predict ketone serum levels in patients with GSD. Full article

Patients with advanced hepatocellular carcinoma (HCC) have a very limited survival rate even after the recent inclusion of kinase inhibitors or immune checkpoint inhibitors in the therapeutic armamentarium. A significant problem with the current proposed therapies is the considerable cost of treatment that may be a serious obstacle in low- and middle-income countries. Implementation of somatostatin analogues (SSAs) has the potential to overcome this obstacle, but due to some negative studies their extensive evaluation came to a halt. However, experimental evidence, both in vitro and in vivo, has revealed various mechanisms of the anti-tumor effects of these analogues, including inhibition of cancer cell proliferation and angiogenesis and induction of apoptosis. Favorable indirect effects such as inhibition of liver inflammation and fibrosis and influence on macrophage-mediated innate immunity have also been noted and are presented in this review. Furthermore, the clinical application of SSAs is both presented and compared with clinical trials of kinase and immune checkpoint inhibitors (ICIs). No direct trials have been performed to compare survival in the same cohort of patients, but the cost of treatment with SSAs is a fraction compared to the other modalities and with significantly less serious side effects. As in immunotherapy, patients with viral HCC (excluding alcoholics), as well as Barcelona stage B or C and Child A patients, are the best candidates, since they usually have a survival prospect of at least 6 months, necessary for optimum results. Reasons for treatment failures are also discussed and further research is proposed. Full article

Oxygen is vital for life as it is required for many different enzymatic reactions involved in intermediate metabolism and xenobiotic biotransformation. Moreover, oxygen consumption in the electron transport chain of mitochondria is used to drive the synthesis of ATP to meet the energetic demands of cells. However, toxic free radicals are generated as byproducts of molecular oxygen consumption. Oxidative stress ensues not only when the production of reactive oxygen species (ROS) exceeds the endogenous antioxidant defense mechanism of cells, but it can also occur as a consequence of an unbalance between antioxidant strategies. Given the important role of hepatocytes in the biotransformation and metabolism of xenobiotics, ROS production represents a critical event in liver physiology, and increasing evidence suggests that oxidative stress contributes to the development of many liver diseases. The present review, which is part of the special issue “Oxidant stress in Liver Diseases”, aims to provide an overview of the sources and targets of ROS in different liver diseases and highlights the pivotal role of oxidative stress in cell death. In addition, current antioxidant therapies as treatment options for such disorders and their limitations for future trial design are discussed. Full article

Non-alcoholic fatty liver disease (NAFLD) is a serious clinicopathological condition that is recognized as the most frequent chronic liver disease, affecting 14–30% of the world’s population. The prevalence of NAFLD has rapidly grown and is correlated with the growth in obesity and type 2 diabetes, among other factors. NAFLD often results in long-term complications including cardiovascular disease, liver cirrhosis, and liver fibrosis. This paper provides an updated overview of NAFLD with a focus on epidemiology, etiology, pathophysiology, screening, complications, and pharmacological therapies to identify effective risk prevention and health promotion. Full article

Alagille syndrome (ALGS) is a genetic-driven condition of chronic cholestasis, involving the intrahepatic bile ducts, heart, vessels, kidneys, skeletal tissues, eyes, and nervous system. Pathological mechanisms are still not defined. JAG1 and NOTCH2 gene mutations are responsible for most cases (96–97%). Diagnosis is based on clinical and laboratory findings—especially the presence of chronic cholestasis—and on genetic assessment. Bone abnormalities, deficiency of liposoluble vitamins, heart issues, and pruritus are the most prominent features of ALGS. Diagnostic imaging, such as ultrasonography, magnetic resonance imaging, and bone mass density assessment, is useful to study hepatic disease progression, estimate the risk of bone fracture, and rule out malignities. Therapy is based on ursodeoxycholic acid, rifampicin, cholestyramine, and supplementation of liposoluble vitamins. New therapeutic approaches are under investigation. Here, we describe a case of an individual with ALGS presenting with congenital chronic cholestasis and a long clinical history, in which pruritus is the main symptom. Full article

One carbon metabolism (1CM) can be defined as the transfer of a carbon unit from one metabolite to another and its replenishment by different sources of labile methyl-group nutrients: primarily choline, methionine, betaine, and serine. This flow of carbon units allows the biosynthesis of nucleotides, amino acids, formylated methionyl-tRNA, polyamines, glutathione, phospholipids, detoxification reactions, maintenance of the redox status and the concentration of NAD, and methylation reactions including epigenetic modifications. That is, 1CM functions as a nutrient sensor and integrator of cellular metabolism. A critical process in 1CM is the synthesis of S-adenosylmethionine (SAMe), the source of essentially all the hundreds of millions of daily methyl transfer reactions in a cell. This versatility of SAMe imposes a tight control in its synthesis and catabolism. Much of our knowledge concerning 1CM has been gained from studies in the production and prevention of nonalcoholic fatty liver disease (NAFLD). Here, we discuss in detail the function of the most important enzymes for their quantitative contribution to maintaining the flux of carbon units through 1CM in the liver and discuss how alterations in their enzymatic activity contribute to the development of NAFLD. Next, we discuss NAFLD subtypes based on serum lipidomic profiles with different risk of cardiovascular disease. Among the latter, we highlight the so-called subtype A for its serum lipidomic profile phenocopying that of mice deficient in SAMe synthesis and because its high frequency (about 50% of the NAFLD patients). Full article