Histologic manifestations of ocrelizumab-associated intestinal and hepatic injury in patients with multiple sclerosis.

AIMS: Ocrelizumab is a humanized anti-CD20-monoclonal antibody that has recently been approved for the treatment of certain types of multiple sclerosis. Isolated case reports of ocrelizumab-associated colitis have been reported in the literature. We present a case series of ocrelizumab-associated intestinal injury with a focus on histopathologic features and report a case of ocrelizumab-associated hepatitis. METHODS AND RESULTS: A retrospective computerized search was conducted from 03/2017 to 08/2022, which identified six patients with suspected or clinically confirmed ocrelizumab-associated intestinal injury and one patient with hepatic injury. Pertinent clinical, endoscopic, and histopathologic findings were reviewed and recorded. Seven patients (six female, one male) were identified with ages ranging from 24 to 68 years. The presenting symptoms included diarrhoea (n = 5), abdominal pain (n = 3), hematochezia (n = 2), and vomiting (n = 1), nausea (n = 1) fever (n = 1), and weight loss (n = 1). Endoscopic findings ranged from normal (n = 1) to patchy colonic inflammation with or without ulceration (n = 4) and decreased mucosal vascular pattern in the rectum (n = 1). Crohn's disease was clinically suspected in two patients and ulcerative colitis in one patient. None of the patients had a prior confirmed diagnosis of inflammatory bowel disease. Histologic patterns of initial colonic injury included acute colitis/proctitis (n = 5), and chronic active colitis (n = 1). Follow-up ranged from 1 to 3 years and 10 months. All patients were alive at follow-up. Follow-up biopsies were available for four patients and findings included focal acute colitis (n = 1), apoptotic colopathy (n = 1) lymphocytic colitis (n = 1), and normal mucosa (n = 1). Four patients were treated with steroids and ocrelizumab was discontinued in three patients. Two patients were symptomatically managed with subsequent resolution of symptoms. The liver biopsy from the patient with a marked hepatic pattern of liver enzyme elevation showed an acute hepatitis pattern of injury with prominent centrilobular necrosis, which resolved upon discontinuation of the drug and treatment with steroids and azathioprine. CONCLUSIONS: The histologic manifestations of ocrelizumab-associated intestinal injury are variable and can mimic inflammatory bowel disease. Hepatic injury can rarely manifest as an acute hepatitis pattern of injury with necrosis. Identifying ocrelizumab-associated injury is paramount in determining management, which often includes discontinuation of ocrelizumab therapy, and/or administration of immunosuppressive therapy.

Histopathological findings from the investigation of paediatric acute hepatitis of unknown aetiology, United Kingdom 2022.

In 2022, there were global reports of increased numbers of acute hepatitis not explained by hepatitis A-E virus infection in children. This manuscript summarises histopathology results from 20 patients in the United Kingdom who underwent liver transplant or had a liver biopsy as part of aetiological investigations. All available histopathological samples were reviewed centrally as part of the outbreak investigation. A working group comprised of infection specialists, hepatologists and histopathologists met virtually to review the cases, presentation, investigations and histopathology. All 20 liver samples had evidence of inflammation without significant interface activity, and submassive confluent pan-lobular or multilobular hepatocellular necrosis. Overall, the predominant histopathological findings were of acute nonspecific hepatitis with submassive hepatic necrosis and central vein perivenulitis and endothelitis. Histopathological findings were a poor indicator of aetiology.

Intrahepatic Cholangiolitis in Cystic Fibrosis (ICCF): An Under-Appreciated Cause of Persistent Cholestasis in Infancy.

Liver histology in infants with cystic fibrosis (CF) and persistent cholestasis is seldom reported in detail. We extend previous observation of a distinctive intrahepatic cholangiopathy (ICCF) to 3 additional infants homozygous for CFTR pathological variants and a fourth infant with a heterozygous CFTR variant, summarizing our experience in 10 infants with CFTR variants and persistent cholestasis. Cholangiograms demonstrate abnormal extrahepatic ducts in 2 infants with CF, 1 with uniform dilatation interpreted as a choledochal cyst and the other with narrow patent ducts. Liver histology in 3 CF homozygotes had prominent ductular reaction with a focally destructive cholangiolitis (inflammation of small bile ducts). The CFTR heterozygote had generalized portal edema with ductular reaction and paucity but no cholangitis. Cholestasis slowly subsided in all infants. ICCF is characterized by severe ductular reaction, prominent cholangiocyte injury, and multifocal necrotizing cholangiolitis. Local aggregates of portal ceroid might suggest previous bile leakage from damaged ducts. ICCF in liver biopsies from infants with cystic fibrosis and persistent cholestasis is unrelated to the specific CFTR genotype. Liver biopsy findings and intraoperative cholangiogram help rule out biliary atresia. ICCF is an early manifestation of CF, a likely prototype for pathogenesis of cystic fibrosis liver disease later in life.

Postinfantile Giant Cell Hepatitis in Native and Allograft Livers: A Multi-Institutional Clinicopathologic Study of 70 Cases.

Postinfantile giant cell hepatitis (PIGCH) is a rare hepatitis pattern in adults with variable etiologies and clinical outcomes. We conducted a multi-institutional retrospective study to define the clinicopathologic characteristics of patients with PIGCH. A total of 70 PIGCH cases were identified and reviewed for pathological features, including fibrosis, cholestasis, inflammation, steatosis, necrosis, and apoptosis, as well as the distribution of giant cells and the maximum number of giant cells per high-power field. Demographic and clinical data, including age, sex, laboratory results, etiologies, and follow-up results, were recorded. Among the 70 cases, 40% (28/70) were associated with autoimmune liver diseases, followed by 9 (13%) with unknown etiology, 8 (11%) with viral infection, 5 (7%) with medications, 5 with combined etiologies, and 4 (6%) with malignancies (mostly chronic lymphocytic leukemia). Notably, another 16% were de novo PIGCH in liver allografts, most of which occurred after a rejection event. During follow-up, 26 (37%) patients died of the disease and 44 (63%) were alive. Deceased patients were characterized by older age (mean age, 54.9 vs 45.5 years; P = .02), higher alkaline phosphatase level (mean value, 253.3U/L vs 166.3 U/L; P = .03), higher fibrosis stage (stage 3-4 vs stage 0-2, 57.7% vs 29.6%; P = .03), being more likely to have de novo PIGCH after transplantation (23.1% vs 11.4%; P = .04), and being less likely to have primary autoimmune liver disease etiology (26.9% vs 47.7%; P = .04). These results indicate that PIGCH is a rare pattern of liver injury associated with different etiologies and variable clinical outcomes. Autoimmune liver disease with PIGCH is associated with better survival, whereas de novo PIGCH in allografts is associated with poorer survival. Older age, higher alkaline phosphatase level, and advanced fibrosis are adverse prognostic factors.

Prediction of biochemical nonresolution in patients with chronic drug-induced liver injury: A large multicenter study.

BACKGROUND AND AIMS: To clarify high-risk factors and develop a nomogram model to predict biochemical resolution or biochemical nonresolution (BNR) in patients with chronic DILI. APPROACH AND RESULTS: Retrospectively, 3655 of 5326 patients with chronic DILI were enrolled from nine participating hospitals, of whom 2866 underwent liver biopsy. All of these patients were followed up for over 1 year and their clinical characteristics were retrieved from electronic medical records. The endpoint was BNR, defined as alanine aminotransferase or aspartate aminotransferase >1.5× upper limit of normal or alkaline phosphatase >1.1× ULN, at 12 months from chronic DILI diagnosis. The noninvasive high-risk factors for BNR identified by multivariable logistic regression were used to establish a nomogram, which was validated in an independent external cohort. Finally, 19.3% (707 of 3655) patients presented with BNR. Histologically, with the increase in liver inflammation grades and fibrosis stages, the proportion of BNR significantly increased. The risk of BNR was increased by 21.3-fold in patients with significant inflammation compared to none or mild inflammation (p < 0.001). Biochemically, aspartate aminotransferase and total bilirubin, platelets, prothrombin time, sex, and age were associated with BNR and incorporated to construct a nomogram model (BNR-6) with a concordance index of 0.824 (95% CI, 0.798-0.849), which was highly consistent with liver histology. These results were successfully validated both in the internal cohort and external cohort. CONCLUSIONS: Significant liver inflammation is a robust predictor associated with biochemical nonresolution. The established BNR-6 model provides an easy-to-use approach to assess the outcome of chronic DILI.

Janus kinase inhibitor Tofacitinib alleviated acute hepatitis induced by lipopolysaccharide/D-galactosamine in mice.

BACKGROUND: The Janus kinase (JAK) is a crucial intracellular signaling hub for numerous cytokines, which is extensively involved in the activation of inflammatory cascade and the induction of inflammatory injury. JAK inhibition provides protective effects in several inflammation-based disorders, but the potential effects of JAK inhibitor in inflammation-based acute hepatitis remain to be investigated. METHODS AND RESULTS: Acute hepatitis is induced by Lipopolysaccharide/D-galactosamine (LPS/D-Gal) in mice with or without the JAK inhibitor Tofacitinib administration. The degree of liver injury, the production of pro-inflammatory cytokines and induction of hepatocytes apoptosis were determined. The results indicated that treatment with Tofacitinib decreased the levels of aminotransferases, attenuated the histological abnormalities in liver and decreased the plasma levels of TNF-α and IL-6 in LPS/D-Gal-insulted mice. In addition, Tofacitinib suppressed the activation of the caspase cascade, decreased the level of cleaved caspase-3, and reduced the count of TUNEL-positive cells. CONCLUSION: Treatment with Tofacitinib alleviated LPS/D-Gal-induced acute hepatitis. JAK maybe become a promising target for the control of inflammation-based liver disorders.

Liver Cell Type-Specific Targeting by Nanoformulations for Therapeutic Applications.

Hepatocytes exert pivotal roles in metabolism, protein synthesis and detoxification. Non-parenchymal liver cells (NPCs), largely comprising macrophages, dendritic cells, hepatic stellate cells and liver sinusoidal cells (LSECs), serve to induce immunological tolerance. Therefore, the liver is an important target for therapeutic approaches, in case of both (inflammatory) metabolic diseases and immunological disorders. This review aims to summarize current preclinical nanodrug-based approaches for the treatment of liver disorders. So far, nano-vaccines that aim to induce hepatitis virus-specific immune responses and nanoformulated adjuvants to overcome the default tolerogenic state of liver NPCs for the treatment of chronic hepatitis have been tested. Moreover, liver cancer may be treated using nanodrugs which specifically target and kill tumor cells. Alternatively, nanodrugs may target and reprogram or deplete immunosuppressive cells of the tumor microenvironment, such as tumor-associated macrophages. Here, combination therapies have been demonstrated to yield synergistic effects. In the case of autoimmune hepatitis and other inflammatory liver diseases, anti-inflammatory agents can be encapsulated into nanoparticles to dampen inflammatory processes specifically in the liver. Finally, the tolerance-promoting activity especially of LSECs has been exploited to induce antigen-specific tolerance for the treatment of allergic and autoimmune diseases.

Regulation of Progression and Resolution of Liver Fibrosis by Immune Cells.

The excessive accumulation of extracellular matrix proteins results in fibrosis-a condition implicated in several diseased conditions, such as nonalcoholic steatohepatitis, viral hepatitis, and autoimmune hepatitis. Despite its prevalence, direct and effective treatments for fibrosis are lacking, warranting the development of better therapeutic strategies. Accumulating evidence has shown that liver fibrosis-a condition previously considered irreversible-is reversible in specific conditions. Immune cells residing in or infiltrating the liver (e.g., macrophages) are crucial in the pathogenesis of fibrosis. Given this background, the roles and action mechanisms of various immune cells and their subsets in the progression and recovery of liver fibrosis, particularly concerning nonalcoholic steatohepatitis, are discussed in this review. Furthermore, the development of better therapeutic strategies based on stage-specific properties and using advanced techniques as well as the mechanisms underlying recovery are elaborated. In conclusion, we consider the review comprehensively provides the present achievements and future possibilities revolving around fibrosis treatment.

A structurally engineered fatty acid, icosabutate, suppresses liver inflammation and fibrosis in NASH.

BACKGROUND & AIMS: Although long-chain omega-3 fatty acids (LCn-3FAs) regulate inflammatory pathways of relevance to non-alcoholic steatohepatitis (NASH), their susceptibility to peroxidation may limit their therapeutic potential. We compared the metabolism of eicosapentaenoic acid (EPA) with an engineered EPA derivative (icosabutate) in human hepatocytes in vitro and their effects on hepatic glutathione metabolism, oxidised lipids, inflammation, and fibrosis in a dietary mouse model of NASH, and in patients prone to fatty liver disease. METHODS: Oxidation rates and cellular partitioning of EPA and icosabutate were compared in primary human hepatocytes. Comparative effects of delayed treatment with either low- (56 mg/kg) or high-dose (112 mg/kg) icosabutate were compared with EPA (91 mg/kg) or a glucagon-like peptide 1 receptor agonist in a choline-deficient (CD), L-amino acid-defined NASH mouse model. To assess the translational potential of these findings, effects on elevated liver enzymes and fibrosis-4 (FIB-4) score were assessed in overweight, hyperlipidaemic patients at an increased risk of NASH. RESULTS: In contrast to EPA, icosabutate resisted oxidation and incorporation into hepatocytes. Icosabutate also reduced inflammation and fibrosis in conjunction with a reversal of CD diet-induced changes in the hepatic lipidome. EPA had minimal effect on any parameter and even worsened fibrosis in association with depletion of hepatic glutathione. In dyslipidaemic patients at risk of NASH, icosabutate rapidly normalised elevated plasma ALT, GGT and AST and reduced FIB-4 in patients with elevated ALT and/or AST. CONCLUSION: Icosabutate does not accumulate in hepatocytes and confers beneficial effects on hepatic oxidative stress, inflammation and fibrosis in mice. In conjunction with reductions in markers of liver injury in hyperlipidaemic patients, these findings suggest that structural engineering of LCn-3FAs offers a novel approach for the treatment of NASH. LAY SUMMARY: Long-chain omega-3 fatty acids are involved in multiple pathways regulating hepatic inflammation and fibrosis, but their susceptibility to peroxidation and use as an energy source may limit their clinical efficacy. Herein, we show that a structurally modified omega-3 fatty acid, icosabutate, overcame these challenges and had markedly improved antifibrotic efficacy in a mouse model of non-alcoholic steatohepatitis. A hepatoprotective effect of icosabutate was also observed in patients with elevated circulating lipids, in whom it led to rapid reductions in markers of liver injury.

CRIg+ Macrophages Prevent Gut Microbial DNA-Containing Extracellular Vesicle-Induced Tissue Inflammation and Insulin Resistance.

BACKGROUND & AIMS: Liver CRIg+ (complement receptor of the immunoglobulin superfamily) macrophages play a critical role in filtering bacteria and their products from circulation. Translocation of microbiota-derived products from an impaired gut barrier contributes to the development of obesity-associated tissue inflammation and insulin resistance. However, the critical role of CRIg+ macrophages in clearing microbiota-derived products from the bloodstream in the context of obesity is largely unknown. METHODS: We performed studies with CRIg-/-, C3-/-, cGAS-/-, and their wild-type littermate mice. The CRIg+ macrophage population and bacterial DNA abundance were examined in both mouse and human liver by either flow cytometric or immunohistochemistry analysis. Gut microbial DNA-containing extracellular vesicles (mEVs) were adoptively transferred into CRIg-/-, C3-/-, or wild-type mice, and tissue inflammation and insulin sensitivity were measured in these mice. After coculture with gut mEVs, cellular insulin responses and cGAS/STING-mediated inflammatory responses were evaluated. RESULTS: Gut mEVs can reach metabolic tissues in obesity. Liver CRIg+ macrophages efficiently clear mEVs from the bloodstream through a C3-dependent opsonization mechanism, whereas obesity elicits a marked reduction in the CRIg+ macrophage population. Depletion of CRIg+ cells results in the spread of mEVs into distant metabolic tissues, subsequently exacerbating tissue inflammation and metabolic disorders. Additionally, in vitro treatment of obese mEVs directly triggers inflammation and insulin resistance of insulin target cells. Depletion of microbial DNA blunts the pathogenic effects of intestinal EVs. Furthermore, the cGAS/STING pathway is crucial for microbial DNA-mediated inflammatory responses. CONCLUSIONS: Deficiency of CRIg+ macrophages and leakage of intestinal EVs containing microbial DNA contribute to the development of obesity-associated tissue inflammation and metabolic diseases.

Sex-Specific Regulation of Interferon-γ Cytotoxicity in Mouse Liver by Autophagy.

BACKGROUND AND AIMS: Interferon-γ (IFNγ) is a central activator of immune responses in the liver and other organs. IFNγ triggers tissue injury and inflammation in immune diseases, which occur predominantly in females for unknown reasons. Recent findings that autophagy regulates hepatotoxicity from proinflammatory cytokines led to an examination of whether defective hepatocyte autophagy underlies sex-specific liver injury and inflammation induced by IFNγ. APPROACH AND RESULTS: A lentiviral autophagy-related 5 (Atg5) knockdown was performed to decrease autophagy-sensitized alpha mouse liver (AML 12) hepatocytes to death from IFNγ in combination with IL-1ß or TNF. Death was necrosis attributable to impaired energy homeostasis and adenosine triphosphate depletion. Male mice with decreased autophagy from a tamoxifen-inducible, hepatocyte-specific Atg5 knockout were resistant to IFNγ hepatotoxicity whereas female knockout mice developed liver injury and inflammation. Female mice had increased IFNγ-induced signal transducer and activator of transcription 1 (STAT1) levels compared to males. Blocking STAT1, but not interferon regulatory factor 1, signaling prevented IFNγ-induced hepatocyte death in autophagy-deficient AML12 cells and female mice. The mechanism of death is STAT1-induced overexpression of nitric oxide synthase 2 (NOS2) as in vitro hepatocyte death and in vivo liver injury were blocked by NOS2 inhibition. CONCLUSIONS: Decreased hepatocyte autophagy sensitizes mice to IFNγ-induced liver injury and inflammation through overactivation of STAT1 signaling that causes NOS2 overexpression. Hepatotoxicity is restricted to female mice, suggesting that sex-specific effects of defective autophagy may underlie the increased susceptibility of females to IFNγ-mediated immune diseases.

Heat Shock Protein 60 Restricts Release of Mitochondrial dsRNA to Suppress Hepatic Inflammation and Ameliorate Non-Alcoholic Fatty Liver Disease in Mice.

Non-alcoholic fatty liver disease (NAFLD), the most common cause of chronic liver disease, consists of fat deposited (steatosis) in the liver due to causes besides excessive alcohol use. The folding activity of heat shock protein 60 (HSP60) has been shown to protect mitochondria from proteotoxicity under various types of stress. In this study, we investigated whether HSP60 could ameliorate experimental high-fat diet (HFD)-induced obesity and hepatitis and explored the potential mechanism in mice. The results uncovered that HSP60 gain not only alleviated HFD-induced body weight gain, fat accumulation, and hepatocellular steatosis, but also glucose tolerance and insulin resistance according to intraperitoneal glucose tolerance testing and insulin tolerance testing in HSP60 transgenic (HSP60Tg) compared to wild-type (WT) mice by HFD. Furthermore, overexpression of HSP60 in the HFD group resulted in inhibited release of mitochondrial dsRNA (mt-dsRNA) compared to WT mice. In addition, overexpression of HSP60 also inhibited the activation of toll-like receptor 3 (TLR3), melanoma differentiation-associated gene 5 (MDA5), and phosphorylated-interferon regulatory factor 3 (p-IRF3), as well as inflammatory biomarkers such as mRNA of il-1ß and il-6 expression in the liver in response to HFD. The in vitro study also confirmed that the addition of HSP-60 mimics in HepG2 cells led to upregulated expression level of HSP60 and restricted release of mt-dsRNA, as well as downregulated expression levels of TLR3, MDA5, and pIRF3. This study provides novel insight into a hepatoprotective effect, whereby HSP60 inhibits the release of dsRNA to repress the TLR3/MDA5/pIRF3 pathway in the context of NAFLD or hepatic inflammation. Therefore, HSP60 may serve as a possible therapeutic target for improving NAFLD.

[Considerations on pathological diagnosis of inherited metabolic liver disease].

A liver biopsy has an important suggestive role in the diagnosis of inherited metabolic liver disease (IMLD). This article introduces the IMLD pathological diagnosis considerations, five types of classification of liver biopsy based on the morphological characteristics (basic normal liver tissue morphology, steatosis, cholestatic disease, storage/deposition, and hepatitis), and a summary of the pathological characteristics of different injury patterns and common diseases in order to provide clues for the correct diagnosis.

GPR40 deficiency is associated with hepatic FAT/CD36 upregulation, steatosis, inflammation, and cell injury in C57BL/6 mice.

G-protein-coupled receptor 40 (GPR40) is highly expressed in pancreatic islets, and its activation increases glucose-stimulated insulin secretion from pancreas. Therefore, GPR40 is considered as a target for type 2 diabetes mellitus (T2DM). Since nonalcoholic fatty liver disease (NAFLD) is associated with T2DM and GPR40 is also expressed by hepatocytes and macrophages, it is important to understand the role of GPR40 in NAFLD. However, the role of GPR40 in NAFLD in animal models has not been well defined. In this study, we fed wild-type or GPR40 knockout C57BL/6 mice a high-fat diet (HFD) for 20 wk and then assessed the effect of GPR40 deficiency on HFD-induced NAFLD. Assays on metabolic parameters showed that an HFD increased body weight, glucose, insulin, insulin resistance, cholesterol, and alanine aminotransferase (ALT), and GPR40 deficiency did not mitigate the HFD-induced metabolic abnormalities. In contrast, we found that GPR40 deficiency was associated with increased body weight, insulin, insulin resistance, cholesterol, and ALT in control mice fed a low-fat diet (LFD). Surprisingly, histology and Oil Red O staining showed that GPR40 deficiency in LFD-fed mice was associated with steatosis. Immunohistochemical analysis showed that GPR40 deficiency also increased F4/80, a macrophage biomarker, in LFD-fed mice. Furthermore, results showed that GPR40 deficiency led to a robust upregulation of hepatic fatty acid translocase (FAT)/CD36 expression. Finally, our in vitro studies showed that GPR40 knockdown by siRNA or a GPR40 antagonist increased palmitic acid-induced FAT/CD36 mRNA in hepatocytes. Taken together, this study indicates that GPR40 plays an important role in homeostasis of hepatic metabolism and inflammation and inhibits nonalcoholic steatohepatitis by possible modulation of FAT/CD36 expression.

Metabolic Inflammation-A Role for Hepatic Inflammatory Pathways as Drivers of Comorbidities in Nonalcoholic Fatty Liver Disease?

Nonalcoholic fatty liver disease (NAFLD) is a global and growing health concern. Emerging evidence points toward metabolic inflammation as a key process in the fatty liver that contributes to multiorgan morbidity. Key extrahepatic comorbidities that are influenced by NAFLD are type 2 diabetes, cardiovascular disease, and impaired neurocognitive function. Importantly, the presence of nonalcoholic steatohepatitis and advanced hepatic fibrosis increase the risk for systemic comorbidity in NAFLD. Although the precise nature of the crosstalk between the liver and other organs has not yet been fully elucidated, there is emerging evidence that metabolic inflammation-in part, emanating from the fatty liver-is the engine that drives cellular dysfunction, cell death, and deleterious remodeling within various body tissues. This review describes several inflammatory pathways and mediators that have been implicated as links between NAFLD and type 2 diabetes, cardiovascular disease, and neurocognitive decline.

Interplay of Liver-Heart Inflammatory Axis and Cannabinoid 2 Receptor Signaling in an Experimental Model of Hepatic Cardiomyopathy.

BACKGROUND AND AIMS: Hepatic cardiomyopathy, a special type of heart failure, develops in up to 50% of patients with cirrhosis and is a major determinant of survival. However, there is no reliable model of hepatic cardiomyopathy in mice. We aimed to characterize the detailed hemodynamics of mice with bile duct ligation (BDL)-induced liver fibrosis, by monitoring echocardiography and intracardiac pressure-volume relationships and myocardial structural alterations. Treatment of mice with a selective cannabinoid-2 receptor (CB2 -R) agonist, known to attenuate inflammation and fibrosis, was used to explore the impact of liver inflammation and fibrosis on cardiac function. APPROACH AND RESULTS: BDL induced massive inflammation (increased leukocyte infiltration, inflammatory cytokines, and chemokines), oxidative stress, microvascular dysfunction, and fibrosis in the liver. These pathological changes were accompanied by impaired diastolic, systolic, and macrovascular functions; cardiac inflammation (increased macrophage inflammatory protein 1, interleukin-1, P-selectin, cluster of differentiation 45-positive cells); and oxidative stress (increased malondialdehyde, 3-nitrotyrosine, and nicotinamide adenine dinucleotide phosphate oxidases). CB2 -R up-regulation was observed in both livers and hearts of mice exposed to BDL. CB2 -R activation markedly improved hepatic inflammation, impaired microcirculation, and fibrosis. CB2 -R activation also decreased serum tumor necrosis factor-alpha levels and improved cardiac dysfunction, myocardial inflammation, and oxidative stress, underlining the importance of inflammatory mediators in the pathology of hepatic cardiomyopathy. CONCLUSIONS: We propose BDL-induced cardiomyopathy in mice as a model for hepatic/cirrhotic cardiomyopathy. This cardiomyopathy, similar to cirrhotic cardiomyopathy in humans, is characterized by systemic hypotension and impaired macrovascular and microvascular function accompanied by both systolic and diastolic dysfunction. Our results indicate that the liver-heart inflammatory axis has a pivotal pathophysiological role in the development of hepatic cardiomyopathy. Thus, controlling liver and/or myocardial inflammation (e.g., with selective CB2 -R agonists) may delay or prevent the development of cardiomyopathy in severe liver disease.

Comparison of clinical features between immune-related sclerosing cholangitis and hepatitis.

Background Immune-related hepatotoxicity is often regarded as immune-related hepatitis (irHepatitis) despite including immune-related sclerosing cholangitis (irSC). This study examined the clinical differences between irSC and irHepatitis. Methods A single-center retrospective study of 530 consecutive patients who received immunotherapy between August 2014 and April 2020 was performed. IrSC and irHepatitis were respectively defined as the radiological presence and absence of bile duct dilation and wall thickness. Results Forty-one patients (7.7%) developed immune-related hepatotoxicity. A CT scan was performed on 12 patients, including 11 of 12 with ≥ grade 3 aminotransferase elevations. IrSC and irHepatitis were diagnosed in 4 (0.8%) and 8 (1.5%) patients, respectively. All the irSC patients had been treated with anti-PD-1. IrHepatitis was more common among patients receiving anti-CTLA-4 than among those receiving anti-PD-1/PD-L1 inhibitors (14%, 7/50 vs. 0.2%, 1/480, P < 0.001). A ≥ grade 2 alkaline phosphatase (ALP) elevation resulting in a cholestatic pattern was seen in all 4 irSC patients. Among the irSC patients, 3 (3/4, 75%) developed ≥ grade 3 aminotransferases elevation. The median duration from the start of immunotherapy until ≥ grade 2 liver enzymes elevation was 257 and 55.5 days in irSC and irHepatitis patients. The median times for progression from grade 2 to 3 liver enzyme elevation were 17.5 and 0 days, respectively. Conclusions IrSC and irHepatitis have different characteristics in the class of immune checkpoint inhibitor and onset pattern. Radiological examination for the diagnosis of irSC should be considered for patients with ≥ grade 2 ALP elevation resulting in a cholestatic pattern. (Registration number J2020-36, Date of registration June 3, 2020).

Aberrant glycosaminoglycan biosynthesis by tumor suppressor EXTL2 deficiency promotes liver inflammation and tumorigenesis through Toll-like 4 receptor signaling.

Certain proteoglycans, consisting of a core protein and glycosaminoglycan (GAG) chains, are among the many types of biomolecules that can function as damage-associated molecular pattern molecules (DAMPs). We, therefore, hypothesized that the expression level and structural alteration of GAGs affect inflammation. We have previously reported that the effects on GAG biosynthesis caused by loss of the tumor suppressor gene exostosin-like 2 (Extl2) influence liver injury and regeneration processes. To examine how altered GAG biosynthesis may underscore the relationship between inflammation and tumorigenesis, we assessed its role in non-alcoholic steatohepatitis and hepatocarcinoma (HCC) induced by dietary obesity and insulin-resistance. We demonstrated that GAGs produced in the absence of EXTL2 act as DAMPs and directly input signals into cells via the Toll-like 4 receptor. In addition, the subsequent transcriptional activation of inflammatory and tumor-promoting cytokines by NF-κB contributes to injury- and inflammation-driven tumor promotion. Thus, dysregulated biosynthesis of GAGs is considered to increase the risk of HCC in a background of obesity and diabetes.

Time and residual hematopoiesis are crucial for PNH clones escape in hepatitis-associated aplastic anemia.

The presence of paroxysmal nocturnal hemoglobinuria (PNH) clones in aplastic anemia (AA) suggests immunopathogenesis, but when and how PNH clones emerge and proliferate are unclear. Hepatitis-associated aplastic anemia (HAAA) is a special variant of AA, contrarily to idiopathic AA, in HAAA the trigger for immune activation is clearer and represented by the hepatitis and thus serves as a good model for studying PNH clones. Ninety HAAA patients were enrolled, including 61 males and 29 females (median age 21 years). Four hundred three of idiopathic AA have been included as controls. The median time from hepatitis to cytopenia was 50 days (range 0-180 days) and from cytopenia to AA diagnosis was 26 days (range 2-370 days). PNH clones were detected in 8 HAAA patients (8.9%) at diagnosis and in 73 patients with idiopathic AA (IAA) (18.1%). PNH cells accounted for 4.2% (1.09-12.33%) of red cells and/or granulocytes and were more likely to be detected in patients with longer disease history and less severe disease. During follow-up, the cumulative incidence of PNH clones in HAAA increased to 18.9% (17/90). Nine HAAA patients newly developed PNH clones, including six immunosuppressive therapy (IST) nonresponders. The clone size was mostly stable during follow-up, and only 2 of 14 patients showed increased clone size without proof of hemolysis. In conclusion, PNH clones were infrequent in newly diagnosed HAAA, but their frequency increased to one that was similar to the IAA frequency during follow-up. These results suggest that the PNH clone selection/expansion process is dynamic and takes time to establish, confirming that retesting for PNH clones during follow-up is crucial.

Discovery of isoliquiritigenin analogues that reverse acute hepatitis by inhibiting macrophage polarization.

Screening a natural product library of 850 compounds yield isoliquiritigenin as an effective anti-inflammatory agent by inhibiting the production of pro-inflammatory NO induced by Pam3CSK4, while its activity accompanied by toxicity. Further studies obtained the optimized isoliquiritigenin derivative SMU-B14, which can inhibit Pam3CSK4 triggered toll-like receptor 2 (TLR2) signaling with low toxicity and high potency. Preliminary mechanism studies indicated that SMU-B14 worked through TLR2/MyD88, phosphorylation of IKKα/ß, leading to the reduce degradation of NF-κB related IKBα and p65 complex, then inhibited the production of inflammatory cytokines, such as TNF-α, IL-6, IL-1ß both in human and murine cell lines. Subsequent polarization experiments showed SMU-B14 significant reversed the polarization of M1 phenotype primary macrophage activated by Pam3CSK4in vitro, and reduced the infiltration of neutrophil and polarization of M1-type macrophage, decreased serum alanine transaminase (ALT), as a result protected liver from being injured in vivo. In summary, we obtained an optimized lead compound SMU-B14 and found it functionally blocked TLR2/MyD88/NF-κB signaling pathway to down-regulate the production of inflammatory cytokines resulted significant liver protection property.