Shah, Vijay H

Background and Aims: Liver fibrosis and cirrhosis are major global health burdens with limited treatments. Activated HSCs drive fibrosis through increased proliferation, migration, collagen deposition and glycolysis. The aim of this study is to elucidate the signaling events that lead to enhanced glycolysis, subsequent HSC activation, and liver fibrosis. Approach and Results: Utilizing a phospho-kinase array, we identified with no lysine kinase 1 (WNK1) as a new kinase in primary human HSCs activated by the profibrotic PDGF-B. PDGF-mediated glycolysis in HSCs was attenuated by the WNK1 selective inhibitor, WNK-IN-11, as measured by live-cell metabolic assay, Glifon-300 fluorescence, Glucose-Glo assay, and glucose transporter 1 immunofluorescence. To understand how WNK1 promotes glycolysis, we employed chemical genetics where an engineered WNK1 carrying threonine 301 to glycine mutation (WNK1 T301G ) mutant with a modified ATP pocket accommodated a specific ATP-γ-S analogue to thio-phosphorylate its substrates. Thio-phosphorylated proteins were analyzed by mass spectrometry, which identified the glycolytic protein, triosephosphate isomerase 1 (TPI1), as a novel WNK1 direct substrate. TPI1 interacted with WNK1 in condensates, membrane-less phase separation structures. Condensate disruption and knockdown of TPI1 or WNK1 reduced HSC proliferation and migration in vitro. In vivo, pharmacological or genetic WNK1 inhibition significantly attenuated liver fibrosis in carbon tetrachloride and high-fat, choline-deficient, L -amino acid diet mouse models. Finally, WNK1 inhibition reduced fibrogenesis ex vivo in human precision-cut liver slices. Conclusions: These findings identify WNK1 as a previously unrecognized kinase that promotes HSC activation and liver fibrosis via TPI1-mediated glycolysis, highlighting the WNK1-TPI1 axis as a potential therapeutic target.

Spatial heterogeneity of liver viscoelasticity, measured at three-dimensional vector MR elastography, positively correlated with metabolic dysfunction–associated steatotic liver disease progression.

Liver fibrosis is characterized by the activation of perivascular hepatic stellate cells (HSCs), the release of fibrogenic nanosized extracellular vesicles (EVs), and increased HSC glycolysis. Nevertheless, how glycolysis in HSCs coordinates fibrosis amplification through tissue zone-specific pathways remains elusive. Here, we demonstrate that HSC-specific genetic inhibition of glycolysis reduced liver fibrosis. Moreover, spatial transcriptomics revealed a fibrosis-mediated up-regulation of EV-related pathways in the liver pericentral zone, which was abrogated by glycolysis genetic inhibition. Mechanistically, glycolysis in HSCs up-regulated the expression of EV-related genes such as Ras-related protein Rab-31 ( RAB31 ) by enhancing histone 3 lysine 9 acetylation on the promoter region, which increased EV release. Functionally, these glycolysis-dependent EVs increased fibrotic gene expression in recipient HSC. Furthermore, EVs derived from glycolysis-deficient mice abrogated liver fibrosis amplification in contrast to glycolysis-competent mouse EVs. In summary, glycolysis in HSCs amplifies liver fibrosis by promoting fibrogenic EV release in the hepatic pericentral zone, which represents a potential therapeutic target.

Abstract The rise in innovative digital health technologies has led a paradigm shift in health care toward personalized, patient‐centric medicine that is reaching beyond traditional brick‐and‐mortar facilities into patients’ homes and everyday lives. Digital solutions can monitor and detect early changes in physiological data, predict disease progression and health‐related outcomes based on individual risk factors, and manage disease intervention with a range of accessible telemedicine and mobile health options. In this review, we discuss the unique transformation underway in the care of patients with liver disease, specifically examining the digital transformation of diagnostics, prediction and clinical decision‐making, and management. Additionally, we discuss the general considerations needed to confirm validity and oversight of new technologies, usability and acceptability of digital solutions, and equity and inclusivity of vulnerable populations.

The fibrogenic wound-healing response in liver increases stiffness. Here, macro and microheterogeneity of liver stiffness correlate with HSC heterogeneity in a hepatic fibrosis mouse model. Fibrogenic HSCs localized in stiff collagen-high areas upregulate the expression of focal adhesion molecule FHL2, which, in turn, promotes extracellular matrix protein expression. These results demonstrate that stiffness heterogeneity at the whole organ, lobular, and cellular level drives an amplification loop of fibrogenesis through specific focal adhesion molecular pathways.

Primary sclerosing cholangitis (PSC) is a chronic fibroinflammatory disease of the biliary tract characterized by cellular senescence and periportal fibrogenesis. Specific disease features that are cell intrinsic and either genetically or epigenetically mediated remain unclear due in part to a lack of appropriate, patient‐specific, in vitro models. Recently, our group developed systems to create induced pluripotent stem cell (iPSC)‐derived cholangiocytes (iDCs) and biliary epithelial organoids (cholangioids). We use these models to investigate whether PSC cholangiocytes are intrinsically predisposed to cellular senescence. Skin fibroblasts from healthy controls and subjects with PSC were reprogrammed to pluripotency, differentiated to cholangiocytes, and subsequently grown in three‐dimensional matrigel‐based culture to induce formation of cholangioids. RNA sequencing (RNA‐seq) on iDCs showed significant differences in gene expression patterns, including enrichment of pathways associated with cell cycle, senescence, and hepatic fibrosis, that correlate with PSC. These pathways also overlapped with RNA‐seq analysis on isolated cholangiocytes from subjects with PSC. Exome sequencing on the subjects with PSC revealed genetic variants of unknown significance in the genes identified in these pathways. Three‐dimensional culture revealed smaller size, lack of a central lumen, and increased cellular senescence in PSC‐derived cholangioids. Congruent with this, PSC‐derived iDCs showed increased secretion of the extracellular matrix molecule fibronectin as well as the inflammatory cytokines interleukin‐6, and chemokine (C‐C motif) ligand 2. Conditioned media (CM) from PSC‐derived iDCs more potently activated hepatic stellate cells compared to control CM. Conclusion: We demonstrated efficient generation of iDCs and cholangioids from patients with PSC that show disease‐specific features. PSC cholangiocytes are intrinsically predisposed to cellular senescence. These features are unmasked following biliary differentiation of pluripotent stem cells and have functional consequences in epithelial organoids.

Alcohol‐associated hepatitis (AAH) is a severe form of liver injury with mortality as high as 30%‐40% at 90 days. As a result of altered immune function in AAH, bacterial infections are common and are associated with poor outcomes. However, determining the risk and subsequent development of infection in patients with AAH remain challenging. We performed a retrospective study of consecutive patients admitted with a diagnosis of AAH at two independent tertiary centers from 1998 to 2018 (test cohort, n = 286) who developed infections following hospitalization. The diagnosis of AAH was confirmed by manual chart review according to the recent National Institute on Alcohol Abuse and Alcoholism definition. Infections were categorized by location and time of diagnosis as hospital‐acquired infection (48 hours after admission until discharge) and posthospital infections (up to 6 months following discharge). The cohort was 66% men, and the median age was 48 (21‐83) years. Corticosteroids were used in 32% of all patients with AAH. The overall infection rate was 24%. Of those with infections, 46% were hospital acquired and 54% were acquired after hospitalization. Variables found to be significant risk factors for bacterial infection included the presence of ascites on admission (hazard ratio [HR], 2.06), corticosteroid administration (HR, 1.70), Model for End‐Stage Liver Disease (MELD) >23 (HR, 2.61), and white blood cell (WBC) count on admission per point (HR, 1.02). Conclusion: In this multicenter cohort study of patients hospitalized with AAH, MELD score, ascites, WBC count, and use of corticosteroids were identified as significant predictors of the development of bacterial infection. We created a novel predictive equation that may be used to aid in the identification of patients with AAH at high risk of infection.

Background and Aims We conducted a comprehensive serum transcriptomic analysis to explore the roles of microRNAs (miRNAs) in alcohol‐associated hepatitis (AH) pathogenesis and their prognostic significance. Approach and Results Serum miRNA profiling was performed in 15 controls, 20 heavy drinkers without liver disease, and 65 patients with AH and compared to publicly available hepatic miRNA profiling in AH patients. Among the top 26 miRNAs, expression of miR‐30b‐5p, miR‐20a‐5p, miR‐146a‐5p, and miR‐26b‐5p were significantly reduced in both serum and liver of AH patients. Pathway analysis of the potential targets of these miRNAs uncovered the genes related to DNA synthesis and cell‐cycle progression pathways, including ribonucleotide reductase regulatory subunit M2 (RRM2), cyclin D1 (CCND1), cyclin D2 (CCND2), MYC proto‐oncogene (MYC), and phorbol‐12‐myristate‐13‐acetate‐induced protein 1 (PMAIP1). We found a significant increase in the protein expression of RRM2, CCND1, and CCND2, but not MYC and PMAIP1, in AH patients who underwent liver transplantation; miR‐26b‐5p and miR‐30b‐5p inhibited the 3′‐UTR (untranslated region) luciferase activity of RRM2 and CCND2, and miR‐20a‐5p reduced the 3′‐UTR luciferase activity of CCND1 and CCND2. During a median follow‐up of 346 days, 21% of AH patients died; these patients had higher body mass index (BMI), Model for End‐Stage Liver Disease (MELD), and serum miR‐30b‐5p, miR‐20a‐5p, miR‐146a‐5p, and miR‐26b‐5p than those who survived. Cox regression analysis showed that BMI, MELD score, miR‐20a‐5p, miR‐146a‐5p, and miR‐26b‐5p predicted mortality. Conclusions Patients with AH attempt to deal with hepatocyte injury by down‐regulating specific miRNAs and up‐regulating genes responsible for DNA synthesis and cell‐cycle progression. Higher expression of these miRNAs, suggestive of a diminished capacity in liver regeneration, predicts short‐term mortality in AH patients.

Background and Aims During liver fibrosis, liver sinusoidal endothelial cells (LSECs) release angiocrine signals to recruit inflammatory cells into the liver. p300, a master regulator of gene transcription, is associated with pathological inflammatory response. Therefore, we examined how endothelial p300 regulates angiocrine signaling and inflammation related to portal hypertension and fibrogenesis. Approach and Results CCl4 or partial inferior vena cava ligation (pIVCL) was used to induce liver injury. Mice with LSEC‐specific p300 deletion (p300 LSECΔ/Δ) or C‐C motif chemokine ligand 2 (Ccl2) deficiency, nuclear factor kappa B (NFκB)–p50 knockout mice, and bromodomain containing 4 (BRD4) inhibitors in wild‐type mice were used to investigate mechanisms of inflammation regulation. Leukocytes were analyzed by mass cytometry by time‐of‐flight. Epigenetic histone marks were modified by CRISPR endonuclease‐deficient CRISPR‐associated 9‐fused with the Krüppel associated box domain (CRISPR‐dCas9‐KRAB)–mediated epigenome editing. Portal pressure and liver fibrosis were reduced in p300 LSECΔ/Δ mice compared to p300 fl/fl mice following liver injury. Accumulation of macrophages was also reduced in p300 LSECΔ/Δ mouse livers. Ccl2 was the most up‐regulated chemokine in injured LSECs, but its increase was abrogated in p300 LSECΔ/Δ mice. While the macrophage accumulation was increased in NFκB‐p50 knockout mice with enhanced NFκB activity, it was reduced in mice with LSEC‐specific Ccl2 deficiency and mice treated with specific BRD4 inhibitors. In vitro, epigenome editing of CCL2 enhancer and promoter regions by CRISPR‐dCas9‐KRAB technology repressed TNFα‐induced CCL2 transcription through H3K9 trimethylation. In contrast, TNFα activated CCL2 transcription by promoting p300 interaction with NFκB and BRD4, leading to histone H3 lysine 27 acetylation at CCL2 enhancer and promoter regions. Conclusions In summary, endothelial p300 interaction with NFκB and BRD4 increases CCL2 expression, leading to macrophage accumulation, portal hypertension, and liver fibrosis. Inhibition of p300 and its binding partners might serve as therapy in the treatment of liver diseases.

Background and Aims Hepatologists often determine whether transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) is preferred for patients with cirrhosis and severe aortic stenosis. The goal of this cohort study is to compare outcomes following TAVR and SAVR in patients with cirrhosis to inform the preferred intervention. Approach and Results Prospectively collected data on 105 consecutive patients with cirrhosis and aortic stenosis who underwent TAVR (n = 55) or SAVR (n = 50) between 2008 and 2016 were reviewed retrospectively. Two control groups were included: 2,680 patients without cirrhosis undergoing TAVR and SAVR and 17 patients with cirrhosis who received medical therapy alone. Among the 105 patients with cirrhosis, the median Society of Thoracic Surgeons score was 3.8% (1.5, 6.9), and the median Model for End‐Stage Liver Disease (MELD) score was 11.6 (9.4, 14.0). The TAVR group had similar in‐hospital (1.8% vs. 2.0%) and 30‐day mortality (3.6% vs. 4.2%) as the SAVR group. During the median follow‐up of 3.8 years (95% confidence interval, 3.0‐6.9), there were 63 (60%) deaths. MELD score (adjusted hazard ratio, 1.13; 95% confidence interval, 1.05‐1.21; P = 0.002) was an independent predictor of long‐term survival. In the subgroup of patients with MELD score <12, the TAVR group had reduced survival compared with the SAVR group (median survival of 2.8 vs. 4.4 years; P = 0.047). However, in those with MELD score ≥12, survival after TAVR, SAVR, and medical therapy was similar (1.3 vs. 2.1 vs. 1.6 years, respectively; P = 0.53). Conclusion In select patients with cirrhosis, both TAVR and SAVR have acceptable and comparable short‐term outcomes. MELD score, but not Society of Thoracic Surgeons score, independently predicts long‐term survival after TAVR and SAVR. For patients with MELD score <12, SAVR is a preferred procedure; however, neither procedure appears superior to medical therapy in patients with MELD score ≥12.