High serum growth differentiation factor 15 is a risk factor for the occurrence of hepatocellular carcinoma in chronic hepatitis B patients treated with nucleos(t)ide analogs.

AIM: Patients with chronic hepatitis B (CHB) remain at risk for hepatocellular carcinoma (HCC) even with nucleos(t)ide analog therapy. We evaluated risk factors for HCC development, including serum hepatitis B virus (HBV) RNA, hepatitis B core-related antigen level, and growth differentiation factor 15 (GDF15) level, a predictor of HCC development in patients with chronic hepatitis C. METHODS: We collected clinical data and stored serum from CHB patients without a history of HCC who were receiving nucleos(t)ide analog treatment for more than 1 year and whose HBV DNA level was less than 3.0 log IU/mL. We measured the serum levels of HBV RNA and GDF15. RESULTS: Among 242 CHB patients, 57 had detectable HBV RNA, and GDF15 was quantified in all patients. The median GDF15 level was 0.86 ng/mL. Cox proportional hazards analysis revealed that male sex and higher GDF15, FIB-4 index, alpha-fetoprotein and gamma-glutamyl transpeptidase were independent risk factors for HCC. The presence of HBV RNA above the lower limit of quantification was not a risk factor. When we set cutoff values based on the Youden index, the cumulative incidence of HCC was significantly higher in the male, AFP ≥3.0 ng/mL, gamma-glutamyl transpeptidase ≥22 U/L, FIB-4 index ≥1.93, and GDF-15 ≥1.17 ng/mL groups. In patients with no or more than three of these five risk factors, the 10-year HCC cumulative incidence rates were 0% and 41.0%, respectively. CONCLUSIONS: High serum GDF15 is an independent risk factor for the occurrence of HCC in CHB patients treated with nucleos(t)ide analogs.

Development of a hepatic differentiation method in 2D culture from primary human hepatocyte-derived organoids for pharmaceutical research.

Human liver organoids derived from primary human hepatocytes (PHHs) are expected to be a hepatocyte source for preclinical in vitro studies of drug metabolism and disposition. Because hepatic functions of these organoids remain low, it is necessary to enhance the hepatic functions. Here, we develop a novel method for two dimensional (2D)-cultured hepatic differentiation from PHH-derived organoids by screening several compounds, cytokines, and growth factors. Hepatic gene expressions in the hepatocyte-like cells differentiated from PHH-derived organoids (Org-HEPs) were greatly increased, compared to those in PHH-derived organoids. The metabolic activities of cytochrome P450 (CYP) 1A2, CYP2C8, CYP2C19, CYP2E1, and CYP3A4 were at levels comparable to those in PHHs. The cell viability of Org-HEPs treated with hepatotoxic drugs was almost the same as that of PHHs. Thus, PHH-derived organoids could be differentiated into highly functional hepatocytes in 2D culture. Thus, Org-HEPs will be useful for pharmaceutical research, including hepatotoxicity tests.

Intrahepatic Exhausted Antiviral Immunity in an Immunocompetent Mouse Model of Chronic Hepatitis B.

BACKGROUND & AIMS: Targeting exhausted immune systems would be a promising therapeutic strategy to achieve a functional cure for HBV infection in patients with chronic hepatitis B (CHB). However, animal models recapitulating the immunokinetics of CHB are very limited. We aimed to develop an immunocompetent mouse model of CHB for intrahepatic immune profiling. METHODS: CHB mice were created by intrahepatic delivery of the Sleeping Beauty transposon vector tandemly expressing the hepatitis B virus (HBV) genome and fumarylacetoacetate hydrolase (FAH) cDNA into C57BL/6J congenic FAH knockout mice via hydrodynamic tail vein injection. We profiled the viral and intrahepatic immune kinetics in CHB mice with or without treatment with recombinant IFNα or the hepatotropic Toll-like receptor 7 agonist SA-5 using single-cell RNA-seq. RESULTS: CHB mice exhibited sustained HBV viremia and persistent hepatitis. They showed intrahepatic expansion of exhausted CD8+ T (Tex) cells, the frequency of which was positively associated with viral load. Recruited macrophages increased in number but impaired inflammatory responses in the liver. The cytotoxicity of mature natural killer (NK) cells also increased in CHB mice. IFNα and SA-5 treatment both resulted in viral suppression with mild hepatic flares in CHB mice. Although both treatments activated NK cells, SA-5 had the capacity to revitalize the impaired function of Tex cells and liver-recruited macrophages. CONCLUSION: Our novel CHB mouse model recapitulated the intrahepatic exhausted antiviral immunity in patients with CHB, which might be able to be reinvigorated by a hepatotropic TLR7 agonist.

Serum growth differentiation factor 15 is a novel biomarker with high predictive capability for liver cancer occurrence in patients with MASLD regardless of liver fibrosis.

BACKGROUND AND AIMS: Although metabolic dysfunction-associated steatotic liver disease (MASLD) patients with a Fib-4 index >1.3 are recommended for fibrosis evaluation via elastography or biopsy, a more convenient method identifying high-risk populations requiring follow-up is needed. We explored the utility of serum levels of growth differentiation factor-15 (GDF15), a cell stress-responsive cytokine related to metabolic syndrome, for stratifying the risk of clinical events in MASLD patients. METHODS: Serum GDF15 levels were measured in 518 biopsy-performed MASLD patients, 216 MASLD patients for validation, and 361 health checkup recipients with MASLD. RESULTS: In the biopsy-MASLD cohort, multivariate analysis indicated that the serum GDF15 level was a risk factor for liver cancer, independent of the fibrosis stage or Fib-4 index. Using a GDF15 cutoff of 1.75 ng/mL based on the Youden index, high-GDF15 patients, regardless of fibrosis status, had a higher liver cancer incidence rate. While patients with a Fib-4 index <1.3 or low-GDF15 rarely developed liver cancer, high-GDF15 patients with a Fib-4 index >1.3 developed liver cancer and decompensated liver events at significantly higher rates and had poorer prognoses. In the validation cohort, high-GDF15 patients had significantly higher incidences of liver cancer and decompensated liver events and poorer prognoses than low-GDF15 patients, whether limited to high-Fib-4 patients. Among health checkup recipients with MASLD, 23.0% had a Fib-4 index >1.3, 2.7% had a Fib-4 index >1.3 and >1.75 ng/mL GDF15. CONCLUSIONS: Serum GDF15 is a biomarker for liver cancer with high predictive capability and is useful for identifying MASLD patients requiring regular surveillance.

Proteomic analysis of serum extracellular vesicles reveals Fibulin-3 as a new marker predicting liver-related events in MASLD.

BACKGROUND: There is a need for novel noninvasive markers for metabolic dysfunction-associated steatotic liver disease (MASLD) to stratify patients at high risk for liver-related events including liver cancer and decompensation. In the present study, we used proteomic analysis of proteins in extracellular vesicles (EVs) to identify new biomarkers that change with fibrosis progression and can predict the development of liver-related events. METHODS: We analyzed serum EVs from 50 patients with MASLD assessed for liver fibrosis by biopsy and identified proteins that altered with advanced fibrosis. A further evaluation was conducted on another cohort of 463 patients with MASLD with biopsy. RESULTS: Eight candidate proteins were identified by proteomic analysis of serum EVs. Among them, serum levels of Fibulin-3, Fibulin-1, and Ficolin 1 correlated with their EV levels. In addition, serum Fibulin-3 and serum Fibulin-1 levels changed significantly with advanced fibrosis. Using another cohort with biopsy, we found that the serum Fibulin-3 concentration was significantly greater in those with advanced fibrosis but that the serum Fibulin-1 concentration was not significantly different. Multivariate Cox proportional hazards analysis revealed that a higher Fibrosis-4 (FIB-4) index and higher serum Fibulin-3 concentration were independent risk factors for liver-related events. When the cutoff value for the serum Fibulin-3 concentration was 6.0 µg/mL according to the Youden index of AUROCs, patients with high serum Fibulin-3 significantly more frequently developed liver-related events than did other patients. Validation using another cohort of 226 patients with clinically diagnosed MASLD confirmed that high serum Fibulin-3 levels are associated with a greater frequency of liver-related events. CONCLUSIONS: Serum Fibulin-3 was identified as a biomarker for predicting liver-related events in patients with MASLD.

The serum tenascin C level is a marker of metabolic disorder-related inflammation affecting pancreatic cancer prognosis.

Obesity is a risk factor for pancreatic cancer development, partly due to the tissue environment of metabolic disorder-related inflammation. We aimed to detect a tissue environment marker triggered by obesity-related metabolic disorders related to pancreatic cancer progression. In murine experiments, Bl6/j mice fed a normal diet (ND) or a high-fat diet (HFD) were orthotopically injected with mPKC1, a murine-derived pancreatic cancer cell line. We used stocked sera from 140 pancreatic cancer patients for analysis and 14 colon polyp patients as a disease control. Compared with ND-fed mice, HFD-fed mice exhibited obesity, larger tumors, and worse prognoses. RNA sequencing of tumors identified tenascin C (TNC) as a candidate obesity-related serum tissue environment marker with elevated expression in tumors of HFD-fed mice. Serum TNC levels were greater in HFD-fed mice than in ND-fed mice. In pancreatic cancer patients, serum TNC levels were greater than those in controls. The TNC-high group had more metabolic disorders and greater CA19-9 levels than did the TNC-low group. There was no relationship between serum TNC levels and disease stage. Among 77 metastatic patients treated with chemotherapy, a high serum TNC concentration was an independent poor prognostic factor. Pancreatic cancer patients with high serum TNC levels experienced progression more rapidly.

Genome-wide loss-of-function genetic screen identifies INSIG2 as the vulnerability of hepatitis B virus-integrated hepatoma cells.

There are approximately 250 million people chronically infected with hepatitis B virus (HBV) worldwide. Although HBV is often integrated into the host genome and promotes hepatocarcinogenesis, vulnerability of HBV integration in liver cancer cells has not been clarified. The aim of our study is to identify vulnerability factors for HBV-associated hepatocarcinoma. Loss-of-function screening was undertaken in HepG2 and HBV-integrated HepG2.2.15 cells expressing SpCas9 using a pooled genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) library. Genes whose guide RNA (gRNA) abundance significantly decreased in HepG2.2.15 cells but not in HepG2 cells were extracted using the MAGeCK algorithm. We identified four genes (BCL2L1, VPS37A, INSIG2, and CFLAR) that showed significant reductions of gRNA abundance and thus potentially involved in the vulnerability of HBV-integrated cancer cells. Among them, siRNA-mediated mRNA inhibition or CRISPR-mediated genetic deletion of INSIG2 significantly impaired cell proliferation in HepG2.2.15 cells but not in HepG2 cells. Its inhibitory effect was alleviated by cotransfection of siRNAs targeting HBV. INSIG2 inhibition suppressed the pathways related to cell cycle and DNA replication, downregulated cyclin-dependent kinase 2 (CDK2) levels, and delayed the G1 -to-S transition in HepG2.2.15 cells. CDK2 inhibitor suppressed cell cycle progression in HepG2.2.15 cells and INSIG2 inhibition did not suppress cell proliferation in the presence of CDK2 inhibitor. In conclusion, INSIG2 inhibition induced cell cycle arrest in HBV-integrated hepatoma cells in a CDK2-dependent manner, and thus INSIG2 might be a vulnerability factor for HBV-associated liver cancer.

The impact of the COVID-19 pandemic on hepatocellular carcinoma diagnosis and treatment in Japan: A multicenter collaborative observational study.

AIM: Coronavirus disease 2019 emerged in December 2019 and spread worldwide. This study aimed to clarify the impact of the coronavirus disease 2019 pandemic on the diagnosis and treatment of hepatocellular carcinoma (HCC) in Japan. METHODS: First, we collected the monthly numbers of HCC-related general medical practices from January 2019 to December 2021 at liver disease-specific medical institutions in Japan. Next, we collected individual clinical information from patients with newly diagnosed HCC during this period. RESULTS: There was a decrease in the number of HCC-related medical practices, including referrals, enhanced abdominal ultrasonography and radiofrequency ablation, in Japan's first state of emergency (SOE; April-May 2020) compared with 2019. Fewer patients were diagnosed with new HCC during the first SOE than before or after it. There was no difference in tumor diameter, number of tumors or Barcelona Clinic Liver Cancer stage between patients diagnosed before the first SOE and those diagnosed during or after the first SOE. The median waiting times for treatment of patients diagnosed during and after the first SOE were 31 and 37 days, which were significantly shorter and not longer than that of patients diagnosed before the first SOE (36 days), respectively. CONCLUSION: The number of HCC-related general medical practices decreased during the first SOE. However, the coronavirus disease 2019 pandemic did not lead to HCC progression by diagnostic delays or cause HCC treatment delays in Japan.

HepaSH cells: Experimental human hepatocytes with lesser inter-individual variation and more sustainable availability than primary human hepatocytes.

Primary human hepatocytes (PHHs) have been commonly used as the gold standard in many drug metabolism studies, regardless of having large inter-individual variation. These inter-individual variations in PHHs arise primarily from genetic polymorphisms, as well as from donor health conditions and storage conditions prior to cell processing. To equalize the effects of the latter two factors, PHHs were transplanted to quality-controlled mice providing human hepatocyte proliferation niches, and engrafted livers were generated. Cells that were harvested from engrafted livers, call this as experimental human hepatocytes (EHH; termed HepaSH cells), were stably and reproducibly produced from 1014 chimeric mice produced by using 17 different PHHs. Expression levels of acute phase reactant (APR) genes as indicators of a systemic reaction to the environmental/inflammatory insults of liver donors varied widely among PHHs. In contrast to PHHs, the expression of APR genes in HepaSH cells was found to converge within a narrower range than in donor PHHs. Further, large individual differences in the expression levels of drug metabolism-related genes (28 genes) observed in PHHs were greatly reduced among HepaSH cells produced in a unified in vivo environment, and none deviated from the range of gene expression levels in the PHHs. The HepaSH cells displayed a similar level of drug-metabolizing enzyme activity and gene expression as the average PHHs but retained their characteristics for drug-metabolizing enzyme gene polymorphisms. Furthermore, long-term 2D culture was possible and HBV infection was confirmed. These results suggest that the stably and reproducibly providable HepaSH cells with lesser inter-individual differences in drug-metabolizing properties, may have a potential to substitution for PHH as practical standardized human hepatocytes in drug discovery research.

STAT3 is Activated by CTGF-mediated Tumor-stroma Cross Talk to Promote HCC Progression.

BACKGROUND & AIMS: Signal transducer and activator of transcription 3 (STAT3) is known as a pro-oncogenic transcription factor. Regarding liver carcinogenesis, however, it remains controversial whether activated STAT3 is pro- or anti-tumorigenic. This study aimed to clarify the significance and mechanism of STAT3 activation in hepatocellular carcinoma (HCC). METHODS: Hepatocyte-specific Kras-mutant mice (Alb-Cre KrasLSL-G12D/+; KrasG12D mice) were used as a liver cancer model. Cell lines of hepatoma and stromal cells including stellate cells, macrophages, T cells, and endothelial cells were used for culture. Surgically resected 12 HCCs were used for human analysis. RESULTS: Tumors in KrasG12D mice showed up-regulation of phosphorylated STAT3 (p-STAT3), together with interleukin (IL)-6 family cytokines, STAT3 target genes, and connective tissue growth factor (CTGF). Hepatocyte-specific STAT3 knockout (Alb-Cre KrasLSL-G12D/+ STAT3fl/fl) downregulated p-STAT3 and CTGF and suppressed tumor progression. In coculture with stromal cells, proliferation, and expression of p-STAT3 and CTGF, were enhanced in hepatoma cells via gp130/STAT3 signaling. Meanwhile, hepatoma cells produced CTGF to stimulate integrin/nuclear factor kappa B signaling and up-regulate IL-6 family cytokines from stromal cells, which could in turn activate gp130/STAT3 signaling in hepatoma cells. In KrasG12D mice, hepatocyte-specific CTGF knockout (Alb-Cre KrasLSL-G12D/+ CTGFfl/fl) downregulated p-STAT3, CTGF, and IL-6 family cytokines, and suppressed tumor progression. In human HCC, single cell RNA sequence showed CTGF and IL-6 family cytokine expression in tumor cells and stromal cells, respectively. CTGF expression was positively correlated with that of IL-6 family cytokines and STAT3 target genes in The Cancer Genome Atlas. CONCLUSIONS: STAT3 is activated by CTGF-mediated tumor-stroma crosstalk to promote HCC progression. STAT3-CTGF positive feedback loop could be a therapeutic target.

TNF receptor-related factor 3 inactivation promotes the development of intrahepatic cholangiocarcinoma through NF-κB-inducing kinase-mediated hepatocyte transdifferentiation.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is a deadly but poorly understood disease, and its treatment options are very limited. The aim of this study was to identify the molecular drivers of ICC and search for therapeutic targets. APPROACH AND RESULTS: We performed a Sleeping Beauty transposon-based in vivo insertional mutagenesis screen in liver-specific Pten -deficient mice and identified TNF receptor-related factor 3 ( Traf3 ) as the most significantly mutated gene in murine ICCs in a loss-of-function manner. Liver-specific Traf3 deletion caused marked cholangiocyte overgrowth and spontaneous development of ICC in Pten knockout and KrasG12D mutant mice. Hepatocyte-specific, but not cholangiocyte-specific, Traf3 -deficient and Pten -deficient mice recapitulated these phenotypes. Lineage tracing and single-cell RNA sequencing suggested that these ICCs were derived from hepatocytes through transdifferentiation. TRAF3 and PTEN inhibition induced a transdifferentiation-like phenotype of hepatocyte-lineage cells into proliferative cholangiocytes through NF-κB-inducing kinase (NIK) up-regulation in vitro. Intrahepatic NIK levels were elevated in liver-specific Traf3 -deficient and Pten -deficient mice, and NIK inhibition alleviated cholangiocyte overgrowth. In human ICCs, we identified an inverse correlation between TRAF3 and NIK expression, with low TRAF3 or high NIK expression associated with poor prognosis. Finally, we showed that NIK inhibition by a small molecule inhibitor or gene silencing suppressed the growth of multiple human ICC cells in vitro and ICC xenografts in vivo. CONCLUSIONS: TRAF3 inactivation promotes ICC development through NIK-mediated hepatocyte transdifferentiation. The oncogenic TRAF3-NIK axis may be a potential therapeutic target for ICC.

Fucosylated haptoglobin is a novel predictive marker of hepatocellular carcinoma after hepatitis C virus elimination in patients with advanced liver fibrosis.

BACKGROUND: Patients with advanced fibrosis are at risk for developing hepatocellular carcinoma (HCC) even after hepatitis C virus (HCV) elimination. We previously reported that serum fucosylated haptoglobin (Fuc-Hp) levels increase as the disease progresses from chronic hepatitis to cirrhosis and then HCC. However, it remains unclear whether serum Fuc-Hp levels can stratify the risk of HCC occurrence after a sustained virological response (SVR) is achieved with direct-acting antivirals (DAAs) in patients with advanced liver fibrosis. METHODS: Among 3,550 patients with chronic hepatitis C treated with DAAs at Osaka University Hospital and related hospitals, the stored sera of 140 patients who were diagnosed with F3 or F4 by liver biopsy before DAA treatment, achieved SVR, and had no history of HCC were available at both baseline and the end of treatment (EOT). We measured the Fuc-Hp levels in these samples. RESULTS: The median serum levels of Fuc-Hp at EOT were significantly lower than those at baseline. During the 54.4-month follow-up period, 16 of 140 patients developed HCC. Multivariate Cox proportional hazards analysis revealed that high Fuc-Hp at EOT, high body mass index (BMI), and low albumin at EOT were independent risk factors for HCC occurrence. Patients with all three factors-high Fuc-Hp, high BMI, and low albumin-had a higher incidence of HCC than patients without these factors. CONCLUSIONS: High serum Fuc-Hp levels at EOT were an independent risk factor for HCC occurrence after SVR. Combined with BMI and albumin, Fuc-Hp can stratify the risk of HCC occurrence among those with advanced fibrosis.

Pentraxin 3 is an adipose tissue-related serum marker for pancreatic cancer cachexia predicting subsequent muscle mass and visceral fat loss.

Cancer cachexia, a paraneoplastic syndrome characterized by ongoing skeletal muscle mass loss, is accompanied by adipose tissue loss and strongly affects chemotherapy endurance. Our aim was to detect a serum marker reflecting pancreatic cancer cachexia and predicting subsequent loss of muscle mass and adipose tissue, focusing on adipose tissue-secreted proteins. Murine-derived pancreatic cancer cells were orthotopically injected into the mouse pancreatic tail. After 3 weeks, RNA sequencing of perigonadal fat and orthotopic tumors was carried out. We analyzed stocked sera and clinical data of metastatic pancreatic cancer patients who received chemotherapy. Perigonadal fat weight/body weight decreased in mice with orthotopic tumors compared to those without tumors. By RNA sequencing and real-time PCR validation, pentraxin 3 (PTX3) was identified as a secreted protein-encoded gene whose expression was significantly higher in the perigonadal fat of mice with orthotopic tumors than in that of mice without orthotopic tumors and was least expressed in orthotopic tumors. Serum PTX3 levels correlated with PTX3 mRNA levels in perigonadal fat and were higher in mice with orthotopic tumors than in those without tumors. In 84 patients diagnosed with metastatic pancreatic cancer, patients with high serum PTX3 levels showed a greater visceral fat loss/month and skeletal muscle mass index (SMI) decrease/month than those with low serum PTX3 levels. High serum PTX3 was an independent risk factor for visceral fat loss, decreased SMI, and poor prognosis. High serum PTX3 in pancreatic cancer patients predicts visceral fat and muscle mass loss and major clinical outcomes of cancer cachexia.

Constitutive Activation of the Tumor Suppressor p53 in Hepatocytes Paradoxically Promotes Non-Cell Autonomous Liver Carcinogenesis.

In chronic liver diseases (CLD), p53 is constitutively activated in hepatocytes due to various etiologies as viral infection, ethanol exposure, or lipid accumulation. This study was aimed to clarify the significance of p53 activation on the pathophysiology of CLDs. In Kras-mutant liver cancer model, murine double minute 2 (Mdm2), a negative regulator of p53, was specifically deleted in hepatocytes [Alb-Cre KrasLSL-G12D Mdm2fl/fl (LiKM; KrasG12D mutation and Mdm2 loss in the liver)]. Accumulation of p53 and upregulation of its downstream genes were observed in hepatocytes in LiKM mice. LiKM mice showed liver inflammation accompanied by hepatocyte apoptosis, senescence-associated secretory phenotype (SASP), and the emergence of hepatic progenitor cells (HPC). More importantly, Mdm2 deletion promoted non-cell autonomous development of liver tumors. Organoids generated from HPCs harbored tumor-formation ability when subcutaneously inoculated into NOD/Shi-scid/IL2Rγ (null) mice. Treatment with acyclic retinoid suppressed growth of HPCs in vitro and inhibited tumorigenesis in LiKM mice. All of the phenotypes in LiKM mice, including accelerated liver tumorigenesis, were negated by further deletion of p53 in hepatocytes (Alb-Cre KrasLSL-G12D Mdm2fl/fl p53fl/fl). Activation of hepatic p53 was noted in liver biopsy samples obtained from 182 patients with CLD, in comparison with 23 normal liver samples without background liver diseases. In patients with CLD, activity of hepatic p53 was positively correlated with the expression of apoptosis, SASP, HPC-associated genes and tumor incidence in the liver after biopsy. In conclusion, activation of hepatocyte p53 creates a microenvironment prone to tumor formation from HPCs. Optimization of p53 activity in hepatocytes is important to prevent patients with CLD from hepatocarcinogenesis. SIGNIFICANCE: This study reveals that activation of p53 in hepatocytes promotes liver carcinogenesis derived from HPCs, which elucidates a paradoxical aspect of a tumor suppressor p53 and novel mechanism of liver carcinogenesis. See related commentary by Barton and Lozano, p. 2824.

Inhibition of nonhomologous end joining-mediated DNA repair enhances anti-HBV CRISPR therapy.

Current anti-hepatitis B virus (HBV) therapies have little effect on covalently closed circular DNA (cccDNA) and fail to eliminate HBV. The clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system has been reported to directly target cccDNA and exert antiviral effects. In this study, we hypothesized that the inhibition of the DNA repair machinery, which is important for the repair of CRISPR-induced double-strand breaks, may enhance the effect of CRISPR targeting cccDNA, and we investigated the antiviral effect of potential combination therapy. The antiviral effect of CRISPR targeting cccDNA (HBV-CRISPR) was evaluated in HBV-susceptible HepG2-hNTCP-C4 cells expressing Cas9 (HepG2-hNTCP-C4-iCas9) or primary human hepatocytes (PHHs) expressing Cas9. Following HBV infection, HBV-CRISPR reduced cccDNA levels, accompanied by decreases in pregenomic RNA (pgRNA) levels and supernatant HBV DNA, hepatitis B surface antigen and hepatitis B e antigen levels in HepG2-hNTCP-C4-iCas9 cells, and PHHs. HBV-CRISPR induced indel formation in cccDNA and up-regulated poly(adenosine diphosphate ribose) polymerase (PARP) activity in HBV-infected HepG2-hNTCP-C4-iCas9 cells. The suppression of PARP2-Histone PARylation factor 1 (HPF1) (involved in the initial step of DNA repair) with small interfering RNA (siRNA) targeting either PARP2 or HPF1 increased the reduction in pgRNA and cccDNA by HBV-CRISPR in HBV-infected HepG2-hNTCP-C4-iCas9 cells. The suppression of DNA Ligase 4 (LIG4) (essential for nonhomologous end joining [NHEJ]) but not breast cancer susceptibility gene (BRCA) (essential for homologous recombination) enhanced the antiviral effect of HBV-CRISPR in HBV-infected HepG2-hNTCP-C4-iCas9 cells. Finally, the clinically available PARP inhibitor olaparib increased the reductions in pgRNA and cccDNA levels induced by HBV-CRISPR in HBV-infected HepG2-hNTCP-C4-iCas9 cells and PHHs. Conclusion: The suppression of the NHEJ-mediated DNA repair machinery enhances the effect of CRISPR targeting cccDNA. The combination of CRISPR and olaparib may represent a therapy for HBV elimination.

Capsid Allosteric Modulators Enhance the Innate Immune Response in Hepatitis B Virus-Infected Hepatocytes During Interferon Administration.

Capsid allosteric modulators (CAMs) inhibit the encapsidation of hepatitis B virus (HBV) pregenomic RNA (pgRNA), which contains a pathogen-associated molecular pattern motif. However, the effect of CAMs on the innate immune response of HBV-infected hepatocytes remains unclear, and we examined this effect in this study. Administration of a CAM compound, BAY41-4109 (BAY41), to HBV-infected primary human hepatocytes (PHHs) did not change the total cytoplasmic pgRNA levels but significantly reduced intracapsid pgRNA levels, suggesting that BAY41 increased extracapsid pgRNA levels in the cytoplasm. BAY41 alone did not change the intracellular interferon (IFN)-stimulated gene (ISG) expression levels. However, BAY41 enhanced antiviral ISG induction by IFN-α in HBV-infected PHHs but did not change ISG induction by IFN-α in uninfected PHHs. Compared with BAY41 or IFN-α alone, coadministration of BAY41 and IFN-α significantly suppressed extracellular HBV-DNA levels. HBV-infected human liver-chimeric mice were treated with vehicle, BAY41, pegylated IFN-α (pegIFN-α), or BAY41 and pegIFN-α together. Compared with the vehicle control, pegIFN-α highly up-regulated intrahepatic ISG expression levels, but BAY41 alone did not change these levels. The combination of BAY41 and pegIFN-α further enhanced intrahepatic antiviral ISG expression, which was up-regulated by pegIFNα. The serum HBV-DNA levels in mice treated with the combination of BAY41 and pegIFN-α were the lowest observed in all the groups. Conclusion: CAMs enhance the host IFN response when combined with exogenous IFN-α, likely due to increased cytoplasmic extracapsid pgRNA.

Dysregulation of PI3K and Hippo signaling pathways synergistically induces chronic pancreatitis via CTGF upregulation.

The role of PI3K and Hippo signaling in chronic pancreatitis (CP) pathogenesis is unclear. Therefore, we assessed the involvement of these pathways in CP by examining the PI3K and Hippo signaling components PTEN and SAV1, respectively. We observed significant decreases in pancreatic PTEN and SAV1 levels in 2 murine CP models: repeated cerulein injection and pancreatic ductal ligation. Additionally, pancreas-specific deletion of Pten and Sav1 (DKO) induced CP in mice. Pancreatic connective tissue growth factor (CTGF) was markedly upregulated in both CP models and DKO mice, and pancreatic CCAAT/enhancer-binding protein-α (CEBPA) expression was downregulated in the CP models. Interestingly, in pancreatic acinar cells (PACs), CEBPA knockdown reduced PTEN and SAV1 and increased CTGF levels in vitro. Furthermore, CEBPA knockdown in PACs induced acinar-to-ductal metaplasia and activation of cocultured macrophages and pancreatic stellate cells. These results were mitigated by CTGF inhibition. CP in DKO mice was also ameliorated by Ctgf gene deletion, and cerulein-induced CP was alleviated by antibody-mediated CTGF neutralization. Finally, we observed significantly decreased PTEN, SAV1, and CEBPA and increased CTGF levels in human CP tissues compared with nonpancreatitis tissues. Taken together, our results indicate that dysregulation of PI3K and Hippo signaling induces CP via CTGF upregulation.

Gab1 in livers with persistent hepatocyte apoptosis has an antiapoptotic effect and reduces chronic liver injury, fibrosis, and tumorigenesis.

Grb2-associated binder 1 (Gab1) is an adaptor protein that is important for intracellular signal transduction by receptor tyrosine kinases that are receptors for various growth factors and plays an important role in rapid liver regeneration after partial hepatectomy and during acute hepatitis. On the other hand, mild liver regeneration is induced in livers of individuals with chronic hepatitis, where hepatocyte apoptosis is persistent; however, the impact of Gab1 on such livers remains unclear. We examined the role of Gab1 in chronic hepatitis. Gab1 knockdown enhanced the decrease in cell viability and apoptosis induced by ABT-737, a Bcl-2/-xL/-w inhibitor, in BNL.CL2 cells, while cell viability and caspase activity were unchanged in the absence of ABT-737. ABT-737 treatment induced Gab1 cleavage to form p35-Gab1. p35-Gab1 was also detected in the livers of mice with hepatocyte-specific Mcl-1 knockout (KO), which causes persistent hepatocyte apoptosis. Gab1 deficiency exacerbated hepatocyte apoptosis in Mcl-1 KO mice with posttranscriptional downregulation of Bcl-XL. In BNL.CL2 cells treated with ABT-737, Gab1 knockdown posttranscriptionally suppressed Bcl-xL expression, and p35-Gab1 overexpression enhanced Bcl-xL expression. Gab1 deficiency in Mcl-1 KO mice activated STAT3 signaling in hepatocytes, increased hepatocyte proliferation, and increased the incidence of liver cancer with the exacerbation of liver fibrosis. In conclusion, Gab1 is cleaved in the presence of apoptotic stimuli and forms p35-Gab1 in hepatocytes. In chronic liver injury, the role of Gab1 in suppressing apoptosis and reducing liver damage, fibrosis, and tumorigenesis is more important than its role in liver regeneration.NEW & NOTEWORTHY Grb2-associated binder 1 (Gab1) is known to contribute to liver regeneration after acute liver injury. However, in chronic liver diseases, Gab1 plays a greater role in suppressing hepatocyte apoptosis than in liver regeneration, resulting in suppression of hepatocyte proliferation, liver fibrosis, and liver carcinogenesis.

The First Case of Coil Embolization for Left Gastric Vein Aneurysm with Liver Cirrhosis: A Case Report and Review of the Literature.

We herein report the first case of interventional radiology for a left gastric vein aneurysm with a gastrorenal shunt. The etiology of the aneurysm was considered secondary to portal hypertension and liver cirrhosis due to hepatitis B virus infection. As the aneurysm was asymptomatic but had a tendency to expand, we successfully performed coil embolization for the aneurysm through a gastrorenal shunt.

Persistent hepatocyte apoptosis promotes tumorigenesis from diethylnitrosamine-transformed hepatocytes through increased oxidative stress, independent of compensatory liver regeneration.

Hepatocellular carcinoma highly occurs in chronic hepatitis livers, where hepatocyte apoptosis is frequently detected. Apoptosis is a mechanism that eliminates mutated cells. Hepatocyte apoptosis induces compensatory liver regeneration, which is believed to contribute to tumor formation. Hepatocyte-specific Mcl-1 knockout mice (Mcl-1Δhep mice) developed persistent hepatocyte apoptosis and compensatory liver regeneration with increased oxidative stress in adulthood but had not yet developed hepatocyte apoptosis at the age of 2 weeks. When diethylnitrosamine (DEN) was administered to 2-week-old Mcl-1Δhep mice, multiple liver tumors were formed at 4 months, while wild-type mice did not develop any tumors. These tumors contained the B-Raf V637E mutation, indicating that DEN-initiated tumorigenesis was promoted by persistent hepatocyte apoptosis. When N-acetyl-L-cysteine was given from 6 weeks of age, DEN-administered Mcl-1Δhep mice had reduced oxidative stress and suppressed tumorigenesis in the liver but showed no changes in hepatocyte apoptosis or proliferation. In conclusion, enhanced tumor formation from DEN-transformed hepatocytes by persistent hepatocyte apoptosis is mediated by increased oxidative stress, independent of compensatory liver regeneration. For patients with livers harboring transformed cells, the control of oxidative stress may suppress hepatocarcinogenesis based on chronic liver injury.