Ticagrelor, but Not Clopidogrel, Attenuates Hepatic Steatosis in a Model of Metabolic Dysfunction-Associated Steatotic Liver Disease.

BACKGROUND: Previous studies have suggested that platelets are associated with inflammation and steatosis and may play an important role in liver health. Therefore, we evaluated whether antiplatelet agents can improve metabolic disorder-related fatty liver disease (MASLD). METHODS: The mice used in the study were fed a high-fat-diet (HFD) and were stratified through liver biopsy at 18 weeks. A total of 22 mice with NAFLD activity scores (NAS) ≥ 4 were randomly divided into three groups (HFD-only, clopidogrel (CLO; 35 mg/kg/day), ticagrelor (TIC; 40 mg/kg/day) group). And then, they were fed a feed mixed with the respective drug for 15 weeks. Blood and tissue samples were collected and used in the study. RESULTS: The TIC group showed a significantly lower degree of NAS and steatosis than the HFD group (p = 0.0047), but no effect on the CLO group was observed. Hepatic lipogenesis markers' (SREBP1c, FAS, SCD1, and DGAT2) expression and endoplasmic reticulum (ER) stress markers (CHOP, Xbp1, and GRP78) only reduced significantly in the TIC treatment group. Inflammation genes (MCP1 and TNF-α) also decreased significantly in the TIC group, but not in the CLO group. Nile red staining intensity and hepatic lipogenesis markers were reduced significantly in HepG2 cells following TIC treatment. CONCLUSION: Ticagrelor attenuated NAS and hepatic steatosis in a MASLD mice model by attenuating lipogenesis and inflammation, but not in the CLO group.

Correlation between cholecystectomy and development of non-alcoholic liver disease in the mouse model.

Background: Several clinical studies have suggested a strong correlation between cholecystectomy and the incidence of non-alcoholic fatty liver disease (NAFLD) although the exact correlation and causal relationship are unclear. This study aimed to investigate whether cholecystectomy increases the incidence of NAFLD or aggravates pre-existing NAFLD. Methods: Standard diet-fed and high-fat (HF) diet-fed mice were subjected to sham operation and cholecystectomy. In study 1, 20 standard diet-fed C57BL/6N mice were sacrificed at months 1, 2, and 4 post-surgery. Meanwhile, in study 2, 25 HF diet-induced NAFLD C57BL/6N mice were biopsied at months 2 and 3 post-surgery and sacrificed at month 6 post-surgery. The hepatic fatty acid and bile acid metabolic pathways and the hepatic bile composition were evaluated. Results: The bodyweight and biochemical parameters (hepatic enzyme, triglyceride, and cholesterol levels) were not significantly different between the standard diet-fed sham and cholecystectomy groups. The NAFLD activity score and the levels of hepatocyte apoptosis markers (Krt18 expression and DNA fragmentation) and de novo lipid synthesis genes were not significantly different between the standard diet-fed sham and cholecystectomy groups. Cholecystectomy did not exacerbate hepatic steatosis, inflammation, and ballooning in the HF diet-fed mice. Hepatic bile acid composition was not markedly different in the sham and cholecystectomy groups fed on standard or HF diet. Cholecystectomy significantly downregulated Cyp7a1 and Cyp27a1 mRNA levels at months 1 and 4 post-surgery but did not affect the degree of steatosis and triglyceride levels. Analysis of bile acid metabolism revealed that taurine-conjugated bile acids were significantly downregulated in the standard diet-fed and high-fat diet-fed mice, but the histological and biochemical parameters were not markedly different. Conclusions: Cholecystectomy did not increase the incidence of NAFLD in standard diet-fed mice. Additionally, NAFLD incidence was not significantly different between the HF diet-fed sham and cholecystectomy groups. Furthermore, the histological parameters were not markedly different between the sham and cholecystectomy groups fed on standard or HF diet. These findings suggest that cholecystectomy does not induce NAFLD.

BTT-105 ameliorates hepatic fibrosis in non-alcoholic fatty liver animal model.

BTT-105 (1-O-hexyl-2,3,5-trimethylhydroquinone), a hydroquinone derivative, is a potent anti-oxidant that was safe and tolerable in phase I clinical trial. This study examined the anti-fibrotic effect of BTT-105 in a mouse model of non-alcoholic fatty liver disease (NAFLD) along with the underlying mechanisms. In vivo, efficacy of BTT-105 evaluated from three kinds of NAFLD models (methionine/choline deficient diet (MCD), high fat diet (HF) and western diet (WD)). Metabolomics and transcriptomics profiling analysis in liver tissues were conducted. In vitro, anti-fibrotic effect of BTT-105 assessed in human hepatic stellated cells (HSCs) and primary mouse HSCs. BTT-105 improved NAFLD activity score in three kinds of NAFLD animal models (MCD, HF, and WD). BTT-105 also decreased levels of hepatic pro-collagen and collagen fibers deposition in liver tissue. Metabolome and transcriptome analysis revealed that BTT-105 decreased lipid metabolites and increased antioxidants in NAFLD mice. In HepG2 cells, BTT-105 enhanced Nrf2-ARE reporter activity in a dose-dependent manner and increased the levels of antioxidant gene expression. BTT-105 showed inhibition of HSCs activation and migration. Gene expression profiling and protein expression showed that BTT-105 increased Nrf2 activation as well as decreased PI3K-Akt pathway in activated HSCs. BTT-105 attenuated ameliorates steatohepatitis and hepatic fibrosis.

Macro-encapsulation of mesenchymal stem cells in acute and chronic liver injury animal models.

BACKGROUND AND AIM: Stem cell treatments using scaffolds for liver disease have been well studied. However, macro-encapsulation of mesenchymal stem cells (MSCs) to minimize or inhibit stem cell homing has not been evaluated. Here, we conducted a proof-of-concept study using MSCs macro-encapsulated in poly lactic-co-glycolic acid in liver disease models. METHODS: Poly lactic-co-glycolic acid semipermeable membranes (surface pore size up to 40 µm) were used as the macro-encapsulation system. Macro-encapsulated pouches were loaded with MSCs and sealed. Each pouch was implanted in the subcutaneous region of the dorsum or interlobular space of the liver. Acute liver injury was induced using thioacetamide intraperitoneal injection thrice a week. For the chronic liver fibrosis model, thioacetamide dose was gradually increased, starting from 100 to 400 mg/kg over 16 weeks (thrice a week). RESULTS: In the acute liver injury model, the treated groups showed decreased liver inflammation and necrosis compared with the control. Hepatic fibrosis decreased in the treated group in the chronic liver fibrosis model compared with that in the control group. Encapsulated MSCs exhibited changed cell morphology and characteristics after implantation, showing increased periodic acid-Schiff staining and CYP2E1 expression. Migration and homing of MSCs into the liver was not observed. Under hypoxic conditions, macro-encapsulated MSCs secreted more growth hormones, including vascular endothelial growth factor, platelet-derived growth factor, angiopoietin-2, and placental growth factor, than monolayered MSCs in vitro. CONCLUSIONS: Macro-encapsulated MSCs attenuate hepatic inflammation and fibrosis by upregulating hypoxia-induced growth hormone secretion in liver disease models.

Decrease in fat de novo synthesis and chemokine ligand expression in non-alcoholic fatty liver disease caused by inhibition of mixed lineage kinase domain-like pseudokinase.

BACKGROUND AND AIM: Receptor-interacting serine/threonine kinase 3 and mixed lineage kinase domain-like pseudokinase (MLKL) have gained attention as apoptosis alternate cell death signaling molecules. We aimed to evaluate the role of MLKL in non-alcoholic fatty liver disease (NAFLD). METHODS: Hepatic tissue MLKL expression was compared between NAFLD patients and healthy controls. High-fat diet was fed to wild-type and MLKL-knockout (KO) mice for 12 weeks. Brown adipose fat tissue was measured by [18 F]-fluorodeoxyglucose positron emission tomography. Energy expenditure was measured by indirect calorimetry. Anti-MLKL effects were also evaluated in in vitro setting using U937 and HepG2 cells. RESULTS: Hepatic tissue MLKL expression increased in NAFLD patients compared with healthy controls. MLKL expression increased according to the degree of steatosis, ballooning, and inflammation. High-fat diet-fed MLKL-KO mice displayed decreased alanine aminotransferase, triglycerides, liver weight, NAFLD activity score (6.3 vs 3.5, P < 0.001), steatosis score (3.0 vs 1.8, P < 0.001), inflammation, and ballooning degeneration compared with wild-type mice. SREBP1c, fatty acid synthase, and SCD-1 expressions decreased in MLKL-KO mice. Adipose tissue F4/80-positive crown-like structures were also reduced in MLKL-KO mice. HepG2 cells treated with necrosulfonamide (an MLKL inhibitor) showed reduced Nile red staining and reduced SREBP1c and SCD-1 expressions. Stimulation of necroptosis using lipopolysaccharide + caspase inhibitor (zVAD) increased CXCL1/2 expressions in U937 monocyte cells. Lipopolysaccharide + zVAD-induced increased expressions of CXCL1/2 were reduced with necrosulfonamide treatment. CONCLUSIONS: Mixed lineage kinase domain-like pseudokinase inhibition has protective effects in non-alcoholic steatohepatitis by decreasing hepatic de novo fat synthesis and chemokine (C-X-C motif) ligand expressions.

The Use of Foxa2-Overexpressing Adipose Tissue-Derived Stem Cells in a Scaffold System Attenuates Acute Liver Injury.

Background/Aims: For the clinical application of stem cell therapy, functional enhancement is needed to increase the survival rate and the engraftment rate. The purpose of this study was to investigate functional enhancement of the paracrine effect using stem cells and hepatocyte-like cells and to minimize stem cell homing by using a scaffold system in a liver disease model. Methods: A microporator was used to overexpress Foxa2 in adipose tissue-derived stem cells (ADSCs), which were cultured in a poly(lactic-co-glycolic acid) (PLGA) scaffold. Later, the ADSCs were cultured in hepatic differentiation medium for 2 weeks by a 3-step method. For in vivo experiments, Foxa2-overexpressing ADSCs were loaded in the scaffold, cultured in hepatic differentiation medium and later were implanted in the dorsa of nude mice subjected to acute liver injury (thioacetamide intraperitoneal injection). Results: Foxa2-overexpressing ADSCs showed greater increases in hepatocyte-specific gene markers (alpha fetoprotein [AFP], cytokeratin 18 [CK18], and albumin), cytoplasmic glycogen storage, and cytochrome P450 expression than cells that underwent the conventional differentiation method. In vivo experiments using the nude mouse model showed that 2 weeks after scaffold implantation, the mRNA expression of AFP, CK18, dipeptidyl peptidase 4 (CD26), and connexin 32 (CX32) was higher in the Foxa2-overexpressing ADSCs group than in the ADSCs group. The Foxa2-overexpressing ADSCs scaffold treatment group showed attenuated liver injury without stem cell homing in the thioacetamide-induced acute liver injury model. Conclusions: Foxa2-overexpressing ADSCs applied in a scaffold system enhanced hepatocyte-like differentiation and attenuated acute liver damage in an acute liver injury model without homing effects.

Feasibility and Stability of Liver Biopsy before Treatment for Preclinical Nonalcoholic Fatty Liver Studies.

BACKGROUND: The heterogeneity of histological findings in preclinical diet-induced nonalcoholic fatty liver disease (NAFLD) animal models is highly challenging. Here, we aimed to evaluate the feasibility and stability of repeated liver biopsy in NAFLD animal models. METHODS: Heterogeneity of diet-induced NAFLD was evaluated at different time points in 52 high-fat diet (HFD), 35 methionine choline-deficiency diet (MCD), and 166 western diet (WD) induced NAFLD mice. Serial liver biopsies (left lateral, right medial, and left medial lobes) were performed monthly for up to 3 months. Mortality rates and changes in food intake, body weight, and liver enzymes were assessed. RESULTS: At 12 weeks, of the HFD animals, 14% and 30% did not develop steatosis and lobular inflammation, respectively; of the MCD animals, 7% did not develop lobular inflammation; and of the WD animals, 14% and 51% did not develop steatosis and lobular inflammation, respectively. The mortality rate of repeated liver biopsy was 1.62% (2/123 mice died). Repeated liver biopsy can be used to trace disease progression. Although body weight, food intake, and liver enzymes slightly changed after biopsy, all recovered within a week. Repeated liver biopsy did not affect the degrees of inflammation and steatosis of the other liver lobes. CONCLUSION: The diet-induced NAFLD models were quite heterogeneous. Our results suggest that the repeated liver biopsy before treatment was applicable and stable in this NAFLD animal study.

Ezetimibe decreased nonalcoholic fatty liver disease activity score but not hepatic steatosis.

BACKGROUND/AIMS: A number of clinical trials reported varying effects of cholesterol lowering agents in nonalcoholic fatty liver disease (NAFLD) patients. We, therefore, assessed the changes in hepatic steatosis and NAFLD activity score (NAS) after treatment with cholesterol lowering agents in NAFLD patients by metaanalysis. METHODS: The Cochrane Library, the MEDLINE, and the Embase databases were searched until May 2015, without any language restrictions, for randomized controlled trials (RCTs) and nonrandomized studies (NRSs). Additional references were obtained from review of bibliography of relevant articles. The quality of evidence was assessed using the grading of recommendations assessment, development and evaluation guidelines. RESULTS: Three RCTs (n = 98) and two NRSs (n = 101) met our study inclusion criteria (adult, NAFLD, liver biopsy). Liver biopsy was performed in all five studies, but only the three studies reported NAS. Ezetimibe significantly decreased NAS (standardized mean difference [SMD], -0.30; 95% confidence interval [CI], -0.57 to -0.03) but not hepatic steatosis in RCT (SMD, -0.1; 95% CI, -0.53 to 0.32), while the effect was significant for both NAS and intrahepatic content in NRSs (SMD, -3.0; 95% CI, -6.9 to 0.91). CONCLUSION: Ezetimibe decreased NAS without improving hepatic steatosis.

Effect of Stem Cell Treatment on Acute Liver Failure Model Using Scaffold.

BACKGROUND: Injecting MSCs via blood vessel is most commonly used method, which has a major drawback of safety. The aim of our study was to evaluate efficacy using scaffold-loaded MSCs in acute liver failure model. METHOD: Acute liver failure was induced in mice using thioacetamide (TAA) (200 mg/kg, i.p) once a day for two consecutive days. The animals were divided in four acute liver failure groups: (1) TAA; (2) empty scaffold; (3) MSCs injected through tail vein; (4) MSC + Scaffold, scaffold loaded with MSCs, to evaluate the mortality and changes in liver function. Polylactic-co-glycolic acid scaffold alone and loaded with human MSCs was implanted on mice dorsum. RESULTS: TAA dose was titrated until one-third mortality rate was achieved. TAA (200 mg/kg) once daily for two consecutive days was injected to establish the acute liver failure model. The mortality of TAA and scaffold groups was 55.9% and 63.2%, respectively. Although, mortality of MSC-TV group decreased 14.7% as compared to TAA group (p = 0.200), MSC + Scaffold group had the lowest mortality (31.4%) (p = 0.013). Cells implanted in PLGA biomaterial were survived until 3 weeks, and their function was increased. Area of hepatic inflammation and necrosis was significantly reduced in MSC-TV and MSC + Scaffold groups; but there was no difference between the two groups. Gene expressions related to inflammation were significantly decreased in MSC-TV and MSC + Scaffold groups compared to TAA group. In MSC + Scaffold group, no migration of stem cells to liver tissue was observed. Although, not all cells in scaffold were stained, some of them were differentiated into hepatocyte-like cells which stained positive for PAS and CYP2E1 antibody. CONCLUSION: Scaffold loaded with MSCs showed protective effects via paracrine signaling on acute liver failure model.

Long term outcome of antiviral therapy in patients with hepatitis B associated decompensated cirrhosis.

AIM: To investigate survival rate and incidence of hepatocellular carcinoma (HCC) in patients with decompensated cirrhosis in the antiviral era. METHODS: We used the Korean Health Insurance Review and Assessment. Korea's health insurance system is a public single-payer system. The study population consisted of 286871 patients who were prescribed hepatitis B antiviral therapy for the first time between 2007 and 2014 in accordance with the insurance guidelines. Overall, 48365 antiviral treatment-naïve patients treated between 2008 and 2009 were included, and each had a follow-up period ≥ 5 years. Data were analyzed for the 1st decompensated chronic hepatitis B (CHB) and treatment-naïve patients (n = 7166). RESULTS: The mean patient age was 43.5 years. The annual mortality rates were 2.4%-19.1%, and 5-year cumulative mortality rate was 32.6% in 1st decompensated CHB treatment-naïve subjects. But the annual mortality rates sharply decreased to 3.4% (2.4%-4.9%, 2-5 year) after one year of antiviral treatment. Incidence of HCC at first year was 14.3%, the annual incidence of HCC decreased to 2.5% (1.8%-3.7%, 2-5 year) after one year. 5-year cumulative incidence of HCC was 24.1%. Recurrence rate of decompensated event was 46.9% at first year, but the annual incidence of second decompensation events in decompensated CHB treatment-naïve patients was 3.4% (2.1%-5.4%, 2-5 year) after one year antiviral treatment. 5-year cumulative recurrence rate of decompensated events was 60.6%. Meanwhile, 5-year cumulative mortality rate was 3.1%, and 5-year cumulative incidence of HCC was 11.5% in compensated CHB treatment-naïve patients. CONCLUSION: Long term outcome of decompensated cirrhosis treated with antiviral agent improved much, and incidence of hepatocellular carcinoma and mortality sharply decreased after one year treatment.

Mismatched effects of receptor interacting protein kinase-3 on hepatic steatosis and inflammation in non-alcoholic fatty liver disease.

AIM: To validate the effects of receptor interacting protein kinase-3 (RIP3) deletion in non-alcoholic fatty liver disease (NAFLD) and to clarify the mechanism of action. METHODS: Wild-type (WT) and RIP3 knockout (KO) mice were fed normal chow and high fat (HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha (TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine (C-X-C motif) ligand (CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated. RESULTS: RIP3KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3KO mice compared to HF diet fed WT mice. RIP3KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers (microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3KO mice. The overall NAFLD Activity Score was the same between WT and RIP3KO mice; however, RIP3KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals (CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pan-caspase inhibitor (necroptotic condition) treatment in monocytes. Neutrophil chemokines (CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes. CONCLUSION: RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.

Caffeine attenuates liver fibrosis via defective adhesion of hepatic stellate cells in cirrhotic model.

BACKGROUND AND AIM: Several epidemiological studies have shown that coffee intake attenuates the progression of liver fibrosis; however, the mechanism is unclear. AIMS: We investigated the direct effects of caffeine on hepatic stellate cells (HSCs) and assessed whether caffeine attenuated intrahepatic fibrosis in rat model of liver cirrhosis. METHODS: Human hepatic stellate cell line, an immortalized human HSCs line, was used in in vitro assay system. Cell migration and proliferation were assessed in presence of various caffeine concentrations (0, 1, 5, and 10 mmol), and levels of procollagen type Ic and α-smooth muscle actin (α-SMA) were measured by Western blot. Severity of liver inflammation and fibrosis were compared between thioacetamide-treated rats with and without caffeine supplementation. RESULTS: Caffeine increased HSCs apoptosis and intracellular F-actin and cyclic adenosine monophosphate expression. Caffeine also inhibited procollagen type Ic and α-SMA expression in a dose- and time-dependent manner. In rat model, caffeine decreased periportal inflammation, levels of inflammatory cells (1.4 ± 0.52 vs 2.6 ± 0.46, P < 0.05), and fibrosis (2.1 ± 0.35 vs 2.9 ± 0.84, P < 0.05). Transforming growth factor-ß and α-SMA expressions were also reduced by caffeine. CONCLUSION: Caffeine attenuates the progression of liver fibrosis by inhibiting HSCs adhesion and activation.