Search Results (89)

Biotransformation refers to the metabolic conversion of endogenous and xenobiotic chemicals into more hydrophilic substances. Xenobiotic biotransformation is accomplished by a restricted number of enzymes with broad substrate specificities. The biotransformation of xenobiotics is catalyzed by various enzyme systems that can be divided into four categories based on the reaction they catalyze. The primary concentration is in cytochrome P450, while the CYP enzymes responsible for xenobiotic biotransformation are located within the hepatic endoplasmic reticulum (microsomes). Cytochrome P450 (CYP450) enzymes are also present in extrahepatic tissues. Enzymes catalyzing biotransformation reactions often determine the intensity and duration of the action of drugs and play a key role in chemical toxicity and chemical tumorigenesis. The structure of a given biotransforming enzyme may differ among individuals, which can cause differences in the rates of xenobiotic biotransformation. The study of the molecular mechanisms underlying chemical liver injury is fundamental for preventing or devising new modalities of treatment for liver injury using chemicals. Active metabolites arise from the biotransformation of a parent drug compound using one or more xenobiotic-processing enzymes to generate metabolites with different pharmacological or toxicological properties. Understanding how exogenous chemicals (xenobiotics) are metabolized, distributed, and eliminated is critical to determining the impact of these compounds on human health. Computational tools such as Biotransformer have been developed to predict all the possible metabolites of xenobiotic and enzymatic profiles that are linked to the production of metabolites. The construction of xenobiotic metabolism maps can predict enzymes catalyzing metabolites capable of binding to DNA. Full article

Representing a growing ‘silent epidemic’, non-alcoholic fatty liver disease (NAFLD) affects around 25–30% of the general population. Alarmingly, NAFLD increases the risk of cardiovascular disease, both independently and through its strong associations with obesity, type 2 diabetes, and metabolic syndrome, whilst posing a substantial burden from an economic and health-related quality of life perspective. Moreover, growing evidence links NAFLD to common mental health disorders including depression, anxiety, and stress. In this context, recent clinical and research attention further focuses on potential additional problems faced by patients with NAFLD, such as perceived stigma, lack of awareness regarding the condition, and possible feelings of loneliness and isolation that might emerge from unmet support needs. To date, despite a wealth of literature on NAFLD, management of the condition remains challenging and not straightforward, with most cases in primary care being treated with lifestyle modification on top of any other comorbidity treatment. However, for many patients with NAFLD, weight loss is hard to accomplish and/or sustain (e.g., patients may lack the skills, confidence, and motivation required to adhere to dietary changes, and/or may have problems limiting opportunities for increased physical activity). Therefore, tailored interventions which are manageable from the perspective of the individual patient with NAFLD could glean greater results. Accordingly, although there is a lack of research exploring the potential benefits of person-centered and compassion-based approaches to the management of NAFLD, in the present review, we draw on evidence from methods utilized in the treatment of other chronic conditions in postulating the view that such approaches might prove beneficial in the future management of NAFLD. Full article

Drugs are prescribed worldwide to treat diseases but with the risk of idiosyncratic drug-induced liver injury (iDILI). The most important difficulty is how best to establish causality. Based on strong evidence and principles of artificial intelligence (AI) to solve complex processes through quantitative algorithms using scored elements, progress was achieved with the Roussel Uclaf Causality Assessment Method (RUCAM) in its original and updated versions, often viewed now as the gold standard. As a highly appreciated diagnostic algorithm, the RUCAM is in global use with around 100,000 iDILI cases published worldwide using RUCAM to assess causality, largely outperforming any other specific causality assessment tool in terms of case numbers. Consequently, the RUCAM helps to establish a list of top-ranking drugs worldwide implicated in iDILI and to describe clinical and mechanistic features of iDILI caused by various drugs. In addition, the RUCAM was recently applied in iDILI cases of patients treated for coronavirus disease 2019 (COVID-19) infections or cancer patients treated with immune checkpoint inhibitors (ICIs), as well as in the search for new treatment options with conventional drugs in iDILI. Analyses of RUCAM-based iDILI cases are helpful to support pathogenetic steps like immune reactions, genetic predisposition as evidenced by human leucocyte antigens (HLA) genotypes for selected drugs, and the role of the gut microbiome. To achieve consistency in data collection, analysis, and specific clinical and pathogenetic presentation, researchers, regulatory agencies, and pharmaceutical firms should place iDILI and the updated RUCAM as the causality tool under one and the same hat in review articles and clinical guidelines for the diagnosis and treatment of iDILI. Full article

The liver is the only organ that can regenerate and regain its original tissue-to-body weight ratio within a short period of time after tissue loss. Insufficient liver regeneration in patients after partial hepatectomy or liver transplantation with partial liver grafts often leads to post-hepatectomy liver failure or small-for-size syndrome, respectively. Enhancing liver regeneration after liver injury might improve outcomes and increase patient survival. Liver regeneration comprises hepatocyte proliferation, and hepatic progenitor cell expansion and differentiation into hepatocytes. The immune system is intensively involved in liver regeneration. The current review provides a comprehensive overview of the diverse roles played by immune cells in liver regeneration. Macrophages, neutrophils, eosinophils, basophils, mast cells, platelets, dendritic cells, type 1 innate lymphoid cells, B cells, and T cells are implicated in promoting liver regeneration, while natural killer cells and overactivated natural killer T cells are supposed to inhibit hepatocyte proliferation. We also highlight the predominant underlying mechanisms mediated by immune cells, which may contribute to the development of novel strategies for promoting liver regeneration in patients with liver diseases. Full article

End-stage liver disease (ESLD) from acute liver failure to compensated advanced chronic liver disease and decompensated cirrhosis at different stages (chronic decompensation, acute decompensation with or without acute-on-chronic liver failure) has high disease severity and poor patient outcome. Infection is a common complication in patients with ESLD and it is associated with a high mortality rate. Multiple mechanisms are involved in this marked susceptibility to infections, noticeably the inadequate immune response known as immune paresis, as part of cirrhosis-associated immune dysfunction (CAID). Specifically in the adaptive immune arm, lymphocyte impairments—including inadequate activation, reduced ability to secrete effector molecules and enhanced immune suppressive phenotypes—result in compromised systemic immune responses and increased risk of infections. This review summarises current knowledge of alterations in adaptive immune responsiveness and their underlying mechanisms in ESLD. Understanding these mechanisms is of crucial importance in the identification of potential therapeutic targets and applications of targeted treatments beyond antimicrobials, such as immunotherapy. Full article

In Egypt, hepatocellular carcinoma (HCC) is the most prevalent cancer in men and the second most prevalent cancer in women. In addition, Egypt has one of the highest prevalences of hepatitis C infection in the world. The aim of the present work was to study the potential role of the 16 KIR genes in the outcome of individuals with chronic hepatitis C virus (HCV) infection in Egypt. The study was carried out under an IRB-approved protocol. Sequence-Specific-Primer-PCR (SSP-PCR) was used for KIR genotyping of germline DNA extracted from peripheral blood leukocytes or from the non-tumor liver of 83 HCC patients, 100 patients with chronic HCV infection without HCC, and 120 matched healthy controls. Out of the 83 HCC patients, only 7 (8.4%) were treated by interferon and/or interferon Ribavirin combination, while for the remaining patients 50 (60.2%) received no prior HCV therapy and 26 (31.3%) were treated with direct-acting antiviral (DAA). Our results showed that KIR haplotype AA that contains more inhibitory KIR genes and fewer activating genes was observed with a significantly lower frequency in HCC patients (6/83, 7.2%) compared to chronic HCV (27/100, 27.0%) (p = 0.0005, OR = 0.21 [0.08–0.53]) and healthy controls (29/119, 24.4%) (p = 0.001, OR = 0.24 [0.09–0.61]). In addition, the frequency of genotype 6 (G6) which contains all the KIR genes was significantly high in the HCC patients (16/83, 19.3%) compared to chronic HCV (8/100, 8.0%) (p = 0.02, OR = 2.7 [1.11–6.79]) and healthy controls (8/119, 6.7%) (p = 0.006, OR = 3.31 [1.35–8.16]). Activating KIR genes 2DS1 and 3DS1 were significantly higher in HCC patients (48/83, 57.83% and 45/83, 54.22%) compared to the chronic HCV patients (36/100, 36% and 34/100, 34%), p = 0.028, 0.027, respectively. Our results are contrary to a prior work on HCC from patients with HCV who were mostly treated by interferon-based therapies. In conclusion, KIR haplotype AA has an important role in host defense against HCC progression especially in patients treated by DAA, suggesting an important role of the KIR genotype status on the outcome of chronic HCV infection. Full article

Hepatitis B virus reactivation (HBVr) is a well-described result of immunosuppressive therapy initiation in various diseases, with the dose and duration of treatment being the main factors determining the probability for reactivation. Such cases have also been described in COVID-19 patients treated with immunosuppressive therapies. Nevertheless, cases of COVID-19 infection that led to HBVr with no concurrent immunosuppressive treatment or any other related cause have also been reported. By that observation, we present a patient followed for a period spanning 20 years with HBeAg negative chronic HBV infection and non-detectable HBV DNA who, after a mild COVID-19 infection treated only with low-dose and short-duration-inhaled corticosteroids (ICS), developed elevated AST and ALT as well as elevated HBV DNA levels. Other etiologies of abnormal liver biochemistries during the diagnostic workout were excluded; thus, the diagnosis of HBV reactivation was established. Treatment with entecavir was initiated, leading to the normalization of AST and ALT levels and a decreasing trend of HBV DNA levels. Since other causes of reactivation were excluded, and the ICS dose and duration were found baring only a very low risk (<1%) for HBVr, COVID-19 infection could be considered the most probable cause of reactivation, hence underlining the need for the close monitoring of those patients. Full article

Congenital hepatic fibrosis/Autosomal recessive polycystic kidney disease (CHF/ARPKD) is an inherited neonatal disease induced by mutations in the PKHD1 gene and characterized by cysts and robust pericystic fibrosis in the liver and kidneys. The PCK rat is an excellent animal model that carries a Pkhd1 mutation and exhibits similar pathophysiology. We performed RNA-Seq analysis on liver samples from PCK rats over a time course of postnatal day (PND) 15, 20, 30, and 90 using age-matched Sprague Dawley (SD) rats as controls to characterize molecular mechanisms of CHF/ARPKD pathogenesis. A comprehensive gene expression analysis identified 1298 differentially expressed genes (DEGs) between PCK and SD rats. The genes overexpressed in the PCK rats at PND30 and 90 were involved cell migration (e.g., Lamc2, Tgfb2, and Plet1), cell adhesion (e.g., Spp1, Adgrg1, and Cd44), and wound healing (e.g., Plat, Celsr1, Tpm1). Connective tissue growth factor (Ctgf) and platelet-derived growth factor (Pdgfb), two genes associated with fibrosis, were upregulated in PCK rats at all time points. Genes associated with MHC class I molecules (e.g., RT1-A2) or involved in ribosome assembly (e.g., Pes1) were significantly downregulated in PCK rats. Upstream regulator analysis showed activation of proteins involved tissue growth (MTPN) inflammation (STAT family members), chromatin remodeling (BRG1), reduction in fibrosis (SMAD7), and inhibition of proteins involved in hepatic differentiation (HNF4α). Immunofluorescence staining revealed that cyst wall epithelium cells also express hepatic progenitor cell markers. The increase in mRNAs of four top upregulated genes, including Reg3b, Aoc1, Tm4sf20, and Cdx2, was confirmed at the protein level using immunohistochemistry. In conclusion, these studies indicate that a combination of increased inflammation, cell migration, wound healing, decreased antifibrotic gene expression, and inhibition of hepatic function are the major underlying pathogenic mechanisms in CHF/ARPKD. Full article

Chronic hepatitis B is still prevalent globally. Many patients are treated for many years with nucleos(t)ide analogues to prevent the virus from actively replicating. However, although it typically requires consecutive treatment for more than 10 years, patients can achieve a functional cure from this virus. This case series presents details of functional cures in patients who received varying nucleos(t)ide therapies for an average of 15.3 years before losses of hepatitis B surface antigen and viral load were observed. It is imperative to understand that abbreviating therapy once a functional cure is achieved may be a possibility in treating patients in order to limit the associated costs and side effects of an otherwise lifelong therapy until other cure drugs are approved. Full article

Tyrosine kinase inhibitors (TKIs) are increasingly popular drugs used to treat more than a dozen different diseases including some forms of cancer. Despite having fewer adverse effects than traditional chemotherapies, they are not without risks. Liver injury is a particular concern. Of the FDA-approved TKIs, approximately 40% cause hepatotoxicity. However, little is known about the underlying pathophysiology. The leading hypothesis is that TKIs are converted by cytochrome P450 3A4 (CYP3A4) to reactive metabolites that damage proteins. Indeed, there is strong evidence for this bioactivation of TKIs in in vitro reactions. However, the actual toxic effects are underexplored. Here, we measured the cytotoxicity of several TKIs in primary mouse hepatocytes, HepaRG cells and HepG2 cells with and without CYP3A4 modulation. To our surprise, the data indicate that CYP3A4 increases resistance to sorafenib and lapatinib hepatotoxicity. The results have implications for the mechanism of toxicity of these drugs in patients and underline the importance of selecting an appropriate experimental model. Full article

Liver regeneration is a compensatory response to tissue injury and loss. It is known that liver regeneration plays a crucial role in recovery following acetaminophen (APAP)-induced hepatotoxicity, which is the major cause of acute liver failure (ALF) in the US. Regeneration increases proportional to the extent of liver injury upon APAP overdose, ultimately leading to regression of injury and spontaneous recovery in most cases. However, severe APAP overdose results in impaired liver regeneration and unchecked progression of liver injury, leading to failed recovery and mortality. Inter-communication between various cell types in the liver is important for effective regenerative response following APAP hepatotoxicity. Various non-parenchymal cells such macrophages, stellate cells, and endothelial cells produce mediators crucial for proliferation of hepatocytes. Liver regeneration is orchestrated by synchronized actions of several proliferative signaling pathways involving numerous kinases, nuclear receptors, transcription factors, transcriptional co-activators, which are activated by cytokines, growth factors, and endobiotics. Overt activation of anti-proliferative signaling pathways causes cell-cycle arrest and impaired liver regeneration after severe APAP overdose. Stimulating liver regeneration by activating proliferating signaling and suppressing anti-proliferative signaling in liver can prove to be important in developing novel therapeutics for APAP-induced ALF. Full article

The activation of hepatic stellate cells (HSCs) is the key event of hepatic fibrosis. Furthermore, activated HSCs also play an important role in the progression of hepatocellular cancer (HCC). Bone morphogenetic protein 14 (BMP14) is a member of the TGF-β/BMP superfamily. So far, most studies have analyzed BMP14 in the context of bone and cartilage formation and homeostasis. The aim of this study was to assess the expression and function of BMP14 in liver fibrosis and HCC. The BMP14 expression increased during the in vitro activation of primary human HSCs and also in mouse models of liver fibrosis. In human HCC, as well as non-tumorous liver tissues, there was a significant correlation between the expression of BMP14 and alpha-smooth-muscle actin (α-SMA), an established marker for HSC activation. RNAi-mediated BMP14 suppression in activated HSCs resulted in the reduced expression of the transcription factors inhibitor of differentiation 1 (ID1) and ID2, known targets of BMP signaling. Interestingly, α-SMA and collagen expression was also reduced in BMP14-depleted cells, while treatment with recombinant BMP14 induced ID1, ID2, α-SMA and collagen expression. In human HCC cell lines, treatment with recombinant BMP14 induced proliferation, migratory activity and colony formation. In summary, our data indicate activated HSCs as a major cellular source of enhanced BMP14 expression in fibrotic liver disease and HCC, and show that BMP14 exhibits pro-fibrogenic as well as pro-tumorigenic effects. Future analyses will reveal the potential of this soluble growth factor as a therapeutic target or prognostic marker for the progression of fibrosis and HCC in patients with chronic liver disease. Full article

Around 118.5 million blood donations are collected annually to save precious lives. The donated blood may also be associated with blood-borne infections. With around 247 million population, Pakistan is an endemic country for viral hepatitis, and there is a high risk of having asymptomatic blood donors among healthy donors. Viral hepatitis is 2.5% prevalent in the general population, and blood donation and its screening have become grave health concerns for Pakistani health authorities. Asymptomatic viral hepatitis needs screening to rule out subliminally diseased individuals, as recommended by the World Health Organization. Knowing the prevalence of the transfusion transmissible infectious (TTIs) agents in healthy blood donors helps assess the disease burden in any population, boosts treatment rates, and precludes dreaded complications in the affected people. The objective of the current study was to determine the prevalence and trends of significant TTIs among blood donors visiting the Armed Forces Institute of Transfusion (AFIT), Rawalpindi, Pakistan. A total of 15,405 blood donors were screened for HBV, HCV, HIV, malaria, and syphilis during this cross-sectional descriptive study. Most donors had an O-positive blood group; AB-negative donors were only 0.7%. Out of the study population, we reported 1.06% HBV, 0.54% HCV, 0.19% HIV, and 0.31% syphilis-positive asymptomatic blood donors. However, no blood donor was found positive for malaria. The Punjab province was reported as the most burdened for TTIs, and youngsters aged 18–27 years were mainly positive, indicating the need to conduct national-level awareness campaigns about TTIs. The stakeholders need to strengthen the blood collection guidelines, and effective performance should be strictly monitored through internal and external audits considering the aim of reaching non-infectious blood products. Full article