Malhi, Harmeet

The efficacy and safety of a fluid‐filled intragastric balloon (IGB) for weight loss in patients with cirrhosis on the liver transplantation (LT) waiting list is unknown. We enrolled stable compensated patients with body mass index >35 kg/m2 and on the waiting list for IGB placement endoscopically for a maximum of 6 months. A total of 8 patients (7 men) aged mean ± SD, 56 ± 4.6 years with Model for End‐Stage Liver Disease–sodium (MELD‐Na) scores 14.1 ± 3.4 experienced weight reduction (146 ± 22.2 kg versus 127 ± 21.6 kg [P = 0.005] with IGB in place and 130 ± 24.6 kg [P = 0.014] at 6 months), with a total body weight loss of 12.2% ± 8.8% with IGBs in place and 10.9% ± 8.9% at 6 months. Body fat decreased from 48.6% ± 5.8% to 40.6% ± 6.4% (P = 0.001) and lean mass increased from 51.3% ± 6% to 59.4% ± 6.4% (P = 0.001). No change in MELD‐Na scores occurred (P = 0.770). Early balloon retrieval was attributed to accommodative symptoms (n = 2) and liver decompensation (n = 1). Mallory Weiss tears (n = 3), but no portal hypertensive bleeding, occurred. Liver decompensation and/or hepatocellular carcinoma (HCC) developed in 3 patients. A total of 4 patients with LT ± sleeve gastrectomy maintained overall weight loss. Of 4 patients who did not receive transplants, 2 experienced weight regain. IGB results in short‐term weight loss in patients with cirrhosis awaiting LT, with body fat loss without lean mass loss. Adverse effects were common. Decompensation and HCC did occur, with uncertainty of the relation to weight loss, and thus careful patient selection and close follow‐up are required.

ATF6α is a critical driver of hepatic stellate cell (HSC) activation in vitro. HSC-specific deletion of Atf6a limits fibrogenesis in vivo despite increased IRE1α signaling. Conditional deletion of Ire1α from HSCs limits fibrogenic gene transcription without impacting overall fibrosis. This could be due in part to observed upregulation of the ATF6α pathway. Dual loss of Atf6a and Ire1a from HSCs worsens fibrosis in vivo through enhanced HSC activation.

AbstractNonalcoholic hepatitis (NASH) is the progressive inflammatory form of nonalcoholic fatty liver disease. Although the mechanisms of hepatic inflammation in NASH remain incompletely understood, emerging literature implicates the proinflammatory environment created by toxic lipid-induced hepatocyte injury, termed lipotoxicity. Interestingly, numerous NASH-promoting kinases in hepatocytes, immune cells, and adipocytes are activated by the lipotoxic insult associated with obesity. In the current review, we discuss recent advances in NASH-promoting kinases as disease mediators and therapeutic targets. The focus of the review is mainly on the mitogen-activated protein kinases including mixed lineage kinase 3, apoptosis signal-regulating kinase 1, c-Jun N-terminal kinase, and p38 MAPK; the endoplasmic reticulum (ER) stress kinases protein kinase RNA-like ER kinase and inositol-requiring protein-1α; as well as the Rho-associated protein kinase 1. We also discuss various pharmacological agents targeting these stress kinases in NASH that are under different phases of development.

Nonalcoholic steatohepatitis (NASH) is an advanced form of nonalcoholic fatty liver disease (NAFLD), resulting from the complex interplay of genetic and environmental risk factors, e.g. diet. The development of novel therapies has been hampered by the lack of a preclinical animal model with high physiologic fidelity to the human condition. A single mutation (I148M) in the patatin‐like phospholipase domain‐containing 3 ( PNPLA3 ) gene is significantly associated with liver fat content and has been identified as the strongest genetic risk factor for NAFLD/NASH, cirrhosis, and hepatocellular carcinoma. We hypothesized that editing PNPLA3 I148M mutation into a genome of Ossabaw, a miniature pig that already has a natural propensity to develop metabolic syndrome, will develop phenotypes that hallmark NAFLD/NASH, and improve preclinical modeling over existing rodent models. PNPLA3 I148M/I148M founders were developed using TALEN‐stimulated homology directed repair in fibroblasts, followed by somatic cell nuclear transfer. Mutant pigs with age/gender‐matched wildtype controls, reared on standard (SD) and specialized western diet (WD), were clinically and histopathologically characterized. No significant differences in circulating triglyceride and liver enzyme levels was observed in our initial cohort on SD of a female mutant pig relative to the wildtype control. However, this mutant female exhibited increased ALP level and a more atherogenic lipoprotein profile with LDL particle concentration than the levels of the respective control. Histopathologically, the mutant female fed on the WD for 3 months exhibited augmented interlobular inflammation, ballooning, as well lipid and collagen buildup in the liver relative to the wildtype counterparts on the same WD or SD. Longitudinal studies in second larger cohort of barrows over six‐months period revealed significantly elevated liver enzymes (ALP, ALT, GGT), bile acids, and lipid profiles (cholesterol, triglyceride, triglyceride‐rich lipoprotein and vLDL) among the mutant versus wildtypes on western diet, substantiating liver pathology and the associated comorbidity of dyslipidemia. Liver histopathology from these barrows on WD over 6‐months did not reveal as significant difference as in the females of the initial cohort, implying gender differences and variances in western diet formulation in susceptibility to NAFLD/NASH that warrant future large‐scale studies. Levels of circulating extracellular vesicles (EVs) were significantly elevated in the sera of mutant pigs relative to wildtypes on the WD, validating this as an important biomarker in NAFLD/NASH pathology. Additionally, the mutant pigs on the WD had significantly greater coronary artery plaque burden than the control groups, in line with the predicted higher comorbidity level in mutants and reinforces the relevance to human clinical medicine. Support or Funding Information NIH (1R43OD023257‐01A1 to TM) and internal funds from Recombinetics Inc., Drs. Chalasani, Sturek, and Malhi.

Background and Aims Alcoholic hepatitis (AH) is diagnosed by clinical criteria, although several objective scores facilitate risk stratification. Extracellular vesicles (EVs) have emerged as biomarkers for many diseases and are also implicated in the pathogenesis of AH. Therefore, we investigated whether plasma EV concentration and sphingolipid cargo could serve as diagnostic biomarkers for AH and inform prognosis to permit dynamic risk profiling of AH subjects. Approach and Results EVs were isolated and quantified from plasma samples from healthy controls, heavy drinkers, and subjects with end‐stage liver disease (ESLD) attributed to cholestatic liver diseases and nonalcoholic steatohepatitis, decompensated alcohol‐associated cirrhosis (AC), and AH. Sphingolipids were quantified by tandem mass spectroscopy. The median plasma EV concentration was significantly higher in AH subjects (5.38 × 1011/mL) compared to healthy controls (4.38 × 1010/mL; P < 0.0001), heavy drinkers (1.28 × 1011/mL; P < 0.0001), ESLD (5.35 × 1010/mL; P < 0.0001), and decompensated AC (9.2 × 1010/mL; P < 0.0001) disease controls. Among AH subjects, EV concentration correlated with Model for End‐Stage Liver Disease score. When EV counts were dichotomized at the median, survival probability for AH subjects at 90 days was 63.0% in the high‐EV group and 90.0% in the low‐EV group (log‐rank P value = 0.015). Interestingly, EV sphingolipid cargo was significantly enriched in AH when compared to healthy controls, heavy drinkers, ESLD, and decompensated AC (P = 0.0001). Multiple sphingolipids demonstrated good diagnostic and prognostic performance as biomarkers for AH. Conclusions Circulating EV concentration and sphingolipid cargo signature can be used in the diagnosis and differentiation of AH from heavy drinkers, decompensated AC, and other etiologies of ESLD and predict 90‐day survival permitting dynamic risk profiling.

Nonalcoholic fatty liver disease (NAFLD) is a heterogeneous group of liver diseases characterized by the accumulation of fat in the liver. The heterogeneity of NAFLD is reflected in a clinical and histologic spectrum where some patients develop isolated steatosis of the liver, termed nonalcoholic fatty liver, whereas others develop hepatocyte injury, ballooning, inflammation, and consequent fibrosis, termed nonalcoholic steatohepatitis (NASH). Systemic insulin resistance is a major driver of hepatic steatosis in NAFLD. Lipotoxicity of accumulated lipids along with activation of the innate immune system are major drivers of NASH. Lipid‐induced sublethal and lethal stress culminates in the activation of inflammatory processes, such as the release of proinflammatory extracellular vesicles and cell death. Innate and adaptive immune mechanisms involving macrophages, dendritic cells, and lymphocytes are central drivers of inflammation that recognize damage‐ and pathogen‐associated molecular patterns and contribute to the progression of the inflammatory cascade. While the activation of the innate immune system and the recruitment of proinflammatory monocytes into the liver in NASH are well known, the exact signals that lead to this remain less well defined. Further, the contribution of other immune cell types, such as neutrophils and B cells, is an area of intense research. Many host factors, such as the microbiome and gut–liver axis, modify individual susceptibility to NASH. In this review, we discuss lipotoxicity, inflammation, and the contribution of interorgan crosstalk in NASH pathogenesis.

Background and Aims Interleukin‐22 has beneficial effects on inflammation and impaired hepatic regeneration that characterize alcohol‐associated hepatitis (AH). F‐652 is a recombinant fusion protein of human interleukin‐22 and immunoglobulin G2 fragment crystallizable. This study aims to assess the safety and efficacy signals of F‐652 in patients with moderate and severe AH. Approach and Results A phase‐2 dose‐escalating study was carried out. F‐652 (10 μg/kg, 30 μg/kg, or 45 μg/kg) administered on days 1 and 7 was tested in 3 patients each with moderate (Model for End‐Stage Liver Disease [MELD] scores: 11‐20) and severe AH (MELD scores: 21‐28). Safety was defined by absence of serious adverse events and efficacy was assessed by Lille score, changes in MELD score, and serum bilirubin and aminotransferases at days 28 and 42. Three independent propensity‐matched comparator patient cohorts were used. Plasma extracellular vesicles and multiplex serum cytokines were measured to assess inflammation and hepatic regeneration. Eighteen patients (9 moderate and 9 severe AH) were enrolled, 66% were male, and the mean age was 48 years. The half‐life of F‐652 following the first dose was 61‐85 hours. There were no serious adverse events leading to discontinuation. The MELD score and serum aminotransferases decreased significantly at days 28 and 42 from baseline (P < 0.05). Day‐7 Lille score was 0.45 or less in 83% patients as compared with 6%, 12%, and 56% among the comparator cohorts. Extracellular vesicle counts decreased significantly at day 28 (P < 0.013). Cytokine inflammatory markers were down‐regulated, and regeneration markers were up‐regulated at days 28 and 42. Conclusions F‐652 is safe in doses up to 45 μg/kg and associated with a high rate of improvement as determined by Lille and MELD scores, reductions in markers of inflammation and increases in markers of hepatic regeneration. This study supports the need for randomized placebo‐controlled trials to test the efficacy of F‐652 in AH.