Clinical performance of Circulating HBV RNA and iTACT-HBcrAg Assays in HBeAg-negative and HBsAg-cleared Chronic Hepatitis B Patients.

Hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg) have been reported to reflect the transcriptional activity of covalently closed circular HBV DNA. We retrospectively investigated the proportions of quantifiable serum HBV RNA and immunoassay for total antigen including complex via pretreatment-hepatitis B core-related antigen (iTACT-HBcrAg) in chronic hepatitis B patients negative for hepatitis B e antigen (HBeAg) and/or with hepatitis B surface antigen (HBsAg) seroclearance. This study included 246 HBeAg-negative HBV-infected patients, who comprised 13 with liver cirrhosis (LC, the LC group), 118 chronic hepatitis (CH, the CH group), and 115 inactive carriers (IC, the IC group), and 44 patients with HBsAg seroclearance. iTACT-HBcrAg and HBV RNA levels were determined using stored serum samples. Higher proportions of the patients had quantifiable iTACT-HBcrAg than HBV RNA in all groups of HBeAg-negative patients (iTACT-HBcrAg: 84.6%, 90.7%, 35.7%, HBV RNA: 23.1%, 26.3%, 14.8%, for the LC, CH, IC groups). With HBsAg seroclearance (HBsAg <0.05 IU/mL), the proportions of quantifiable samples for HBV RNA were also lower than iTACT-HBcrAg (0% for HBV RNA). Thus, iTACT-HBcrAg was more often detectable than circulating HBV RNA in this study population. Further long-term prospective evaluation of iTACT-HBcrAg is desirable for its utilization in clinical practice.

Serum Angiopoietin-2 Levels Predict the Development of Hepatocellular Carcinoma following Hepatitis C Virus Eradication Using Direct-Acting Antiviral Agents.

INTRODUCTION: Our previous studies showed that serum angiopoietin-2 (Ang-2) and C-X-C motif chemokine ligand 10 (CXCL10) levels predicted improvement in liver fibrosis following sustained virological response (SVR) of hepatitis C virus (HCV) obtained with administration of with direct-acting antiviral agents (DAAs). These levels were evaluated retrospectively as predictive indicators of hepatocellular carcinoma (HCC) development following SVR. METHODS: We enrolled individuals from a historical cohort of 89 chronic HCV patients without history of HCC at baseline and with SVR following DAA therapy and had baseline serum levels of Mac-2 binding protein glycosylation isomer ≥2.0 cut-off index (C.O.I.). RESULTS: Multivariate analyses revealed that only the Ang-2 level at 24 weeks following the end of treatment (EOT24W) was significantly related to HCC development (hazard ratio 2.27; p = 0.003). This result was reproduced in individuals without history of HCC and with advanced liver fibrosis (M2BPGi level ≥3.3 C.O.I. at baseline). Time-dependent receiver operating characteristic curve analyses for the future risk of developing HCC within 5 years of follow-up (5y-HCC) showed the best cut-off Ang-2 level at the EOT24W was 2,780 pg/mL, and significantly stratified the cumulative incidence of HCC (≥2,780 vs. < 2,780 pg/mL, 5y-HCC: 45.5 vs. 8.2%, p < 0.001). CONCLUSIONS: At the EOT24W, serum Ang-2 level predicts the likelihood of developing HCC following SVR to DAA therapy.

Prognostic nutritional index after introduction of atezolizumab with bevacizumab predicts prognosis in advanced hepatocellular carcinoma: A multicenter study.

INTRODUCTION: Atezolizumab plus bevacizumab (Atez/Bev) is the preferred treatment for advanced hepatocellular carcinoma (HCC). However, biomarkers of therapeutic efficacy have remained unclear. We took a retrospective approach to explore the role of prognostic nutritional index (PNI) for predicting the outcomes of Atez/Bev treatment. METHODS: One hundred twenty-five HCC patients were enlisted; these patients received Atez/Bev treatment and underwent dynamic computerized tomography/magnetic resonance imaging to determine the treatment response on at least one occasion between October 2020 and January 2023, and their PNI before treatment and at the beginning of the second cycle (PNI-2c) was evaluated. RESULTS: During the initial evaluation, 2 (2%), 28 (22%), 70 (56%), and 25 (20%) patients exhibited a complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD), respectively. Patients with non-PD tended to have higher PNI at baseline and PNI-2c than those with PD (p = 0.245 and 0.122, respectively), with optimal baseline PNI and PNI-2c cut-off values of 42.6 and 40.4, respectively. PNI at baseline could not be used to predict overall survival (OS) or progression-free survival (PFS). However, PNI-2c predicted OS and PFS (PNI-2c ≥ 40.4 vs. < 40.4: 25.3 vs. 16.2 months, P = 0.008 for OS; 12.7 vs. 8.4 months, P = 0.036 for PFS). A multivariate analysis showed a significant association between PNI-2c and OS. CONCLUSIONS: PNI-2c is a predictor of prognosis in HCC patients treated with Atez/Bev therapy.

Efficacy of antiviral therapy for the prevention of mother-to-child transmission of hepatitis B virus and the risk of postpartum hepatitis flare after discontinuation of antiviral therapy.

The use of nucleos(t)ide analogs (NAs) is recommended for mothers with a high viral load of hepatitis B virus (HBV) during the second or third trimester of pregnancy. However, postpartum hepatitis flares can occur in some cases. We examined the efficacy of NA administration for the prevention of mother-to-child transmission of hepatitis B virus, and evaluated the risk of postpartum hepatitis flares in mothers after NA discontinuation. Nine pregnant women with a high viral load (HBV DNA ≥5.3 log IU/mL) received tenofovir disoproxil fumarate (TDF) at approximately 28 weeks of gestation, and TDF was discontinued at 4-10 weeks after delivery. We evaluated the virological and biochemical parameters in mothers after TDF discontinuation. Hepatitis flares in mothers were defined as alanine transaminase level ≥60 U/L. None of the infants developed any congenital anomaly or acquired HBV infection during infancy. Hepatitis flares occurred within 6 months after TDF discontinuation in five of seven cases, whereas two cases were lost to follow-up. Furthermore, three cases required the resumption of NA use. NA administration was highly effective against mother-to-child-transmission of HBV in pregnant women with high HBV DNA levels. However, hepatitis flares were commonly observed after NA discontinuation in the postpartum period. Patients should be followed up carefully after NA discontinuation, and NA resumption should be considered based on a comprehensive assessment of virological and biochemical parameters.

Serum inducible protein 10 kDa/C-X-C motif chemokine 10 levels predict regression of M2BPGi-based liver fibrosis after hepatitis C virus eradication by direct-acting antiviral agents.

AIM: It is desirable to identify predictors of regression of liver fibrosis after achieving sustained virological response by anti-hepatitis C virus (anti-HCV) therapy. We retrospectively investigated the serum interferon-γ inducible protein 10 kDa (IP-10) level as a predictive indicator of regression of liver fibrosis after successful hepatitis C virus eradication by direct-acting antiviral agents (DAAs) therapy. METHODS: The study participants were recruited from a historical cohort of 116 chronically hepatitis C virus-infected patients who had achieved sustained virological response by DAAs therapy and whose serum Mac-2 binding protein glycosylation isomer (M2BPGi) levels at baseline (before DAAs therapy) were ≥2.0 cut-off index. We defined patients with M2BPGi levels <1.76 and ≥1.76 cut-off index at 2 years after the end of treatment (EOT) as the regression (n = 71) and non-regression (n = 45) groups, respectively. RESULTS: Multivariate analyses revealed that the albumin-bilirubin score at baseline, and albumin-bilirubin score, Fibrosis-4 index at 24 weeks after the EOT, and serum IP-10 change from baseline to 24 weeks after the EOT (IP-10 change) were significantly associated with regression of M2BPGi-based liver fibrosis. In addition, IP-10 change was significantly associated with regression of M2BPGi-based liver fibrosis by a multivariate analysis, even when the serum M2BPGi levels were aligned by propensity score matching and in patients with advanced M2BPGi-based liver fibrosis: M2BPGi levels ≥3.3 cut-off index at baseline. CONCLUSIONS: Serum IP-10 change from baseline to 24 weeks after the EOT is a feasible predictor of regression of M2BPGi-based liver fibrosis after achieving sustained virological response with DAA therapy.

Serum interleukin-6 levels at the start of the second course of atezolizumab plus bevacizumab therapy predict therapeutic efficacy in patients with advanced hepatocellular carcinoma: a multicenter analysis.

BACKGROUND AND AIM: Serum interleukin-6 (IL-6) before the administration of atezolizumab plus bevacizumab (Atez + Bev) is a prognostic biomarker in patients with hepatocellular carcinoma (HCC) treated with Atez + Bev. We previously revealed that the neutrophil-to-lymphocyte ratio and serum chemokine levels during treatment with Atez + Bev were more useful as prognostic biomarkers. Therefore, we examined the predictive ability of serum IL-6 for the efficacy of Atez + Bev in patients with HCC. METHODS: We enrolled 94 patients with HCC who received treatment with Atez + Bev. Initial responses were assessed through dynamic computed tomography or magnetic resonance imaging. The levels of IL-6 in serum were measured before and at the initiation of the second course of Atez + Bev. Subsequently, the relationship of IL-6 levels with treatment efficacy was evaluated. RESULTS: IL-6 levels at the initiation of the second course tended to be higher in patients with progressive disease versus those with non-progressive disease in the initial evaluation (P = 0.054). Moreover, the cutoff value (7.4 pg/mL) was useful in stratifying patients by overall survival (i.e. low vs high: not reached vs 21.4 months, respectively, P = 0.001) and progression-free survival (low vs high: 11.9 vs 5.2 months, respectively, P = 0.004). This result was reproduced in patients with HCC who received Atez + Bev as first-line therapy. In the multivariate analyses, IL-6 levels at the initiation of the second course were independent predictive factors for progression-free and overall survival. CONCLUSIONS: Serum levels of IL-6 at the initiation of the second course of treatment may predict Atez + Bev efficacy and prognosis in HCC.

Cell-Free Protein Expression by a Reconstituted Transcription-Translation System Energized by Sugar Catabolism.

Cooperation between catabolism and anabolism is crucial for maintaining homeostasis in living cells. The most fundamental systems for catabolism and anabolism are the glycolysis of sugars and the transcription-translation (TX-TL) of DNA, respectively. Despite their importance in living cells, the in vitro reconstitution of their cooperation through purified factors has not been achieved, which hinders the elucidation of the design principle in living cells. Here, we reconstituted glycolysis using sugars and integrated it with the PURE system, a commercial in vitro TX-TL kit composed of purified factors. By optimizing key parameters, such as glucokinase and initial phosphate concentrations, we determined suitable conditions for their cooperation. The optimized system showed protein synthesis at up to 33% of that of the original PURE system. We observed that ATP consumption in upstream glycolysis inhibits TX-TL and that this inhibition can be alleviated by the co-addition of glycolytic intermediates, such as glyceraldehyde 3-phosphate, with glucose. Moreover, the system developed here simultaneously synthesizes a subset of its own enzymes, that is, glycolytic enzymes, in a single test tube, which is a necessary step toward self-replication. As glycolysis and TX-TL provide building blocks for constructing cells, the integrated system can be a fundamental material for reconstituting living cells from purified factors.

Kinetics of HBcrAg and HBsAg using highly sensitive iTACT assays in chronic hepatitis B patients with HBsAg seroclearance.

Two novel assays have been developed, iTACT-hepatitis B core-related antigen (iTACT-HBcrAg) and iTACT-hepatitis B surface antigen (iTACT-HBsAg) assays. We investigated the longitudinal profiles of iTACT-HBcrAg- and -HBsAg in patients with HBsAg seroclearance (SC) (<0.05 IU/mL). This study comprises 60 HBV-infected patients with HBsAg SC, 27 in chronic hepatitis/liver cirrhosis (CH/LC) group and 33 in inactive carrier (IC) group. Longitudinal profiles of iTACT-HBcrAg and -HBsAg were examined using stored serum samples. The median period from HBsAg SC to iTACT-HBcrAg loss or to the last observation was longer in the CH/LC group than the IC group (39 vs. -3 months, p = 0.004), but this tendency was not observed in that by iTACT-HBsAg. Comparing the times of iTACT-HBcrAg and -HBsAg loss, the rate of patients who lost HBcrAg first was significantly higher in the IC group (p = 0.008). The cumulative incidence rate of iTACT-HBcrAg loss after HBsAg SC was higher in the IC group that the CH/LC group (p = 0.002). Patients in the CH/LC group had higher rates of detectable iTACT-HBcrAg than those in the IC group after HBsAg SC, suggesting that the presence of HBcrAg possibly contribute to the progression of chronic hepatitis B.

Insertion and deletion mutations preserved in SARS-CoV-2 variants.

The insertion/deletion (indel) mutation profiles of SARS-CoV-2 variants, including Omicron, remain unclear. We compared whole-genome sequences from various lineages and used preserved indels to infer the ancestral relationships between different lineages. Thirteen indel patterns from twelve sites were seen in ≥ 2 sequences; six of these sites were located in the N-terminal domain of the viral spike gene. Preserved indels in the coding regions were also identified in the non-structural protein 3 (Nsp3), Nsp6, and nucleocapsid genes. Seven of the thirteen indel patterns were specific to the Omicron variants, four of which were observed in BA.1, making it the most mutated variant. Other preserved indels observed in the Omicron variants were also seen in Alpha and/or Gamma, but not Delta, suggesting that Omicron is phylogenetically more proximal to Alpha. We demonstrated distinct profiles of preserved indels among SARS-CoV-2 variants and sublineages, suggesting the importance of indels in viral evolution.

Phase-Separated Giant Liposomes for Stable Elevation of α-Hemolysin Concentration in Lipid Membranes.

Staphylococcus aureus α-hemolysin (αHL) is one of the most popular proteins in nanopore experiments within lipid membranes. Higher concentrations of αHL within the lipid membrane are desirable to enhance the mass transport capacity through nanopores. However, the reconstitution of αHL at high concentrations is associated with the problem of membrane lytic disruption. In this study, we present a method that effectively increases αHL concentration while maintaining membrane stability. This method is achieved by using phase-separated giant liposomes, where coexisting liquid-disordered (Ld) and liquid-ordered phases (Lo) are enriched in unsaturated lipids and saturated lipids with cholesterol (Chol), respectively. Fluorescence observation of αHL in liposomes revealed that the presence of Chol facilitates αHL insertion into the membrane. Despite the preferential localization of αHL in the Ld phase rather than the Lo phase, the coexistence of both Lo and Ld phases prevents membrane disruption in the presence of concentrated αHL. We have explained this stabilization mechanism considering the lower membrane tension exhibited by phase-separated liposomes compared to homogeneous liposomes. Under hypertonic conditions, we have successfully increased the local concentration of αHL by invagination of the lipid-only region in the Ld phase, leaving αHL behind. This method exhibits potential for the reconstitution of various nanochannels and membrane proteins that prefer the Ld phase over the Lo phase, thus enabling the production of giant liposomes at high concentrations and the replication of the membrane-crowding condition observed in cells.

Efficacy of minocycline hydrochloride aspiration sclerotherapy with additional monoethanolamine oleate aspiration sclerotherapy for symptomatic hepatic cysts.

AIM: Minocycline hydrochloride (MINO) aspiration sclerotherapy (AS) has been widely used for treating hepatic cysts (HC). However, cyst recurrence remains problematic. Information on monoethanolamine oleate (EO) AS, another effective HC treatment, is currently limited. We investigated the efficacy of EO on ineffective MINO treatments, and the relationship between MINO AS and cyst fluid pH. METHODS: A total of 22 cases with symptomatic HC underwent AS with 500 mg of MINO from January 2016 to June 2021. Cyst fluid pH was measured before and after MINO injection. Cyst volume ratio (CVR, %) after 2 weeks was calculated as follows:cyst volume 2 weeks after MINO injection / pre-treatment cyst volume × 100. Treatment was completed if CVR after 2 weeks was ≤35% (MINO-group). For patients with CVR >35%, 2 g of EO was added (MINO/EO-group). Cyst volume ratio was measured every 12 months thereafter. RESULTS: There were no recurrence symptoms in any of the patients during follow-up. Of the 22 cases, 21 had CVR ≤20% after 12 months. The MINO/EO-group (n = 8) tended to have smaller CVRs after 12 months than the MINO-group (n = 14). Cyst volume ratio after 2 weeks was correlated to pH change (p = 0.012) and was larger in patients whose pH decreased by <1.5 (p = 0.015). All adverse events were mild, including in elderly patients. CONCLUSION: Adding EO is an effective and safe treatment for symptomatic HC when MINO AS alone is insufficient. Patients with pH decreases of <1.5 should be considered for additional EO treatment.

Outcome of nucleos(t)ide analog cessation in patients with treatment for prevention of or against hepatitis B virus reactivation.

AIM: We retrospectively investigated patients with administration of nucleos(t)ide analogs (NAs) for prevention of or against hepatitis B virus (HBV) reactivation, and their clinical outcomes after cessation of the NA. METHODS: We enrolled 180 patients who were positive for HBsAg when they started immunosuppressive therapy or chemotherapy and an NA was administered to prevent HBV reactivation (HBV carrier group), and 82 patients with resolved HBV infection who started administration of an NA after HBV reactivation (de novo HBV group). Cessation of the NA depended on each physician's judgment without definite criteria. RESULTS: A total of 27 patients in the HBV carrier group and 22 in the de novo HBV group stopped NA therapy. In the HBV carrier group, 16 patients experienced virological relapse, which was defined as HBV DNA levels ≥20 IU/ml, and one with hematological disease had an alanine aminotransferase flare after cessation of NA. Of the 16 patients, the NA was reintroduced in three, whereas, the remaining 13 had low levels of HBV DNA and no alanine aminotransferase flare. In the de novo HBV group, virological relapse occurred in six patients, and one with hematological disease had an alanine aminotransferase flare after cessation of the NA. The NA was reintroduced in four of the six patients. CONCLUSIONS: We may be able to consider to cease NA therapy proactively in HBV carriers and resolved patients with non-hematological disease, if their primary diseases are under remission after completion of immunosuppressive therapy or chemotherapy. However, careful follow up is necessary after stopping NA therapy.

The neutrophil-to-lymphocyte ratio at the start of the second course during atezolizumab plus bevacizumab therapy predicts therapeutic efficacy in patients with advanced hepatocellular carcinoma: A multicenter analysis.

AIM: Atezolizumab plus bevacizumab (Atez/Bev) therapy is expected to have good therapeutic efficacy for patients with advanced hepatocellular carcinoma (HCC). However, the clinical indicators that predict therapeutic efficacy have not been established. We retrospectively investigated whether the neutrophil-to-lymphocyte ratio (NLR) during Atez/Bev therapy could predict therapeutic efficacy. METHOD: In total, 110 patients with HCC were enrolled; they were treated with Atez/Bev therapy and evaluated for their initial response by dynamic CT or MRI at least once between October 2020 and July 2022. RESULTS: Of the 110 patients with HCC at the initial evaluation, two (2%) showed a complete response (CR), 22 (20%) partial response (PR), 62 (56%) stable disease (SD), and 24 (21%) progressive disease (PD). The NLR at the start of the second course (NLR-2c) increased from CR + PR to SD to PD. There was no significant association between the baseline NLR and the initial therapeutic response. Patients with CR + PR had lower NLR-2c values than those with SD + PD (p < 0.001) and the optimal cut-off value of NLR-2c was 1.97. Patients with NLR-2c <1.97 had better overall survival and progression-free survival (PFS) than those with NLR-2c ≥1.97 (p = 0.005 for overall survival; p < 0.001 for PFS). A multivariate analysis showed that female sex, higher PIVKA-II levels at baseline, and higher values of NLR-2c were significantly associated with poorer PFS. CONCLUSIONS: The NLR-2c value predicts the initial therapeutic response and prognosis of patients with HCC treated with Atez/Bev therapy.

Trinucleotide Substitutions at Two Locations in the SARS-CoV-2 Nucleocapsid (N) Gene.

The genomes of sarbecoviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), incorporate mutations with short sequence exchanges based on unknown processes. Currently, the presence of such short-sequence exchanges among the genomes of different SARS-CoV-2 lineages remains uncertain. In the present study, multiple SARS-CoV-2 genome sequences from different clades or sublineages were collected from an international mass sequence database and compared to identify the presence of short sequence exchanges. Initial screening with multiple sequence alignments identified two locations with trinucleotide substitutions, both in the nucleocapsid (N) gene. The first exchange from 5'-GAT-3' to 5'-CTA-3' at nucleotide positions 28,280-28,282 resulted in a change in the amino acid from aspartic acid (D) to leucine (L), which was predominant in clade GRY (Alpha). The second exchange from 5'-GGG-3' to 5'-AAC-3' at nucleotide positions 28,881-28,883 resulted in an amino acid change from arginine and glycine (RG) to lysine and arginine (KR), which was predominant in GR (Gamma), GRY (Alpha), and GRA (Omicron). Both trinucleotide substitutions occurred before June 2020. The sequence identity rate between these lineages suggests that coincidental succession of single-nucleotide substitutions is unlikely. Basic local alignment search tool sequence search revealed the absence of intermediating mutations based on single-base substitutions or overlapping indels before the emergence of these trinucleotide substitutions. These findings suggest that trinucleotide substitutions could have developed via an en bloc exchange. In summary, trinucleotide substitutions at two locations in the SARS-CoV-2 N gene were identified. This mutation may provide insights into the evolution of SARS-CoV-2.

Characterization of the membrane penetration-enhancing peptide S19 derived from human syncytin-1 for the intracellular delivery of TAT-fused proteins.

Although cell-penetrating peptides such as the HIV-derived TAT peptide have been used as tools for the intracellular delivery of therapeutic peptides and proteins, a problem persists: the endosomal escape efficiency is low. Previously, we found that the fusogenic peptide S19, derived from the human protein syncytin-1, enhance the endosomal escape efficiency of proteins that incorporated by endocytosis via TAT. In this study, we first performed Ala-scanning mutagenesis of S19, and found that all Ile, Val, Leu and Phe with high ß-sheet forming propensities in S19 are important for the intracellular uptake of S19-TAT-fused proteins. In a secondary structure analysis of the mutated S19-TAT peptides in the presence of liposomes mimicking late endosomes (LEs), the CD spectra of V3A and I4A mutants with low uptake activity showed the appearance of an α-helix structure, whereas the mutant G5A retained both the uptake activity and the ß-structure. In addition, we investigated the appropriate linking position and order of the S19 and TAT peptides to a cargo protein including an apoptosis-induced peptide and found that both the previous C-terminal S19-TAT tag and the N-terminal TAT-S19 tag promote the cytoplasmic delivery of the fusion protein. These results and previous results suggest that the interaction of TAT with the LE membrane causes a structural change in S19 from a random coil to a ß-strand and that the subsequent parallel ß-sheet formation between two S19 peptides may promote adjacent TAT dimerization, resulting in endosomal escape from the LE membrane.

Cell-Size Space Regulates the Behavior of Confined Polymers: From Nano- and Micromaterials Science to Biology.

Polymer micromaterials in a liquid or gel phase covered with a surfactant membrane are widely used materials in pharmaceuticals, cosmetics, and foods. In particular, cell-sized micromaterials of biopolymer solutions covered with a lipid membrane have been studied as artificial cells to understand cells from a physicochemical perspective. The characteristics and phase transitions of polymers confined to a microscopic space often differ from those in bulk systems. The effect that causes this difference is referred to as the cell-size space effect (CSE), but the specific physicochemical factors remain unclear. This study introduces the analysis of CSE on molecular diffusion, nanostructure transition, and phase separation and presents their main factors, i.e., short- and long-range interactions with the membrane surface and small volume (finite element nature). This serves as a guide for determining the dominant factors of CSE. Furthermore, we also introduce other factors of CSE such as spatial closure and the relationships among space size, the characteristic length of periodicity, the structure size, and many others produced by biomolecular assemblies through the analysis of protein reaction-diffusion systems and biochemical reactions.

Bile acid dysmetabolism in the gut-microbiota-liver axis under hepatitis C virus infection.

BACKGROUND & AIMS: We recently analysed and reported the features of the micro biome under hepatitis C virus (HCV) infection, but the effect of HCV infection on bile acid (BA) metabolism in the gut-liver axis remains poorly understood. The aim of this study was to clarify the characteristics of the gut-liver axis in HCV-infected patients. METHODS: The faecal BAs composition and gut microbiota from 100 chronic hepatitis C (CHC) patients were compared with those from 23 healthy individuals. For transcriptional analysis of the liver, 22 mild CHC (fibrosis stages [F] 0-2) and 42 advanced CHC (F3-4) cases were compared with 12 healthy individuals. The findings were confirmed using chimeric mice with human hepatocytes infected with HCV HCR6. RESULTS: Chronic hepatitis C patients, even at earlier disease stages, showed BA profiles distinct from healthy individuals, in which faecal deoxycholic acid (DCA) was significantly reduced and lithocholic acid or ursodeoxycholic acid became dominant. The decrease in faecal DCA was correlated with reduction in commensal Clostridiales and increase in oral Lactobacillales. Impaired biosynthesis of cholic acid (CA) was observed as a reduction in the transcription level of cytochrome P450 8B1 (CYP8B1), a key enzyme in CA biosynthesis. The reductions in faecal DCA and liver CYP8B1 were also observed in HCV-infected chimeric mice. CONCLUSIONS: Chronic hepatitis C alters the intestinal BA profile, in association with the imbalance of BA biosynthesis, which differs from the pattern in NAFLD. These imbalances appear to drive disease progression through the gut-microbiome-liver axis.

Serum angiopoietin-2 levels predict regression of Mac-2 binding protein glycosylation isomer-based liver fibrosis after hepatitis C virus eradication by direct-acting antiviral agents.

AIM: It is desirable to identify predictors of regression of liver fibrosis after achieving a sustained virologic response (SVR) by direct-acting antiviral agents (DAAs) to antihepatitis C virus (HCV) therapy. Here, we retrospectively investigated the serum angiopoietin-2 (Ang-2) level as a predictive indicator of regression of liver fibrosis after successful HCV eradication by DAA therapy. METHODS: The study subjects were recruited from a historical cohort of 109 chronically HCV-infected patients who had achieved SVR by DAA therapy and whose serum Mac-2 binding protein glycosylation isomer (M2BPGi) levels at baseline (before DAA therapy) were ≥2.0 the cut-off index (COI). We defined patients with M2BPGi levels <1.76 and ≥1.76 COI at 2 years after the end of treatment (EOT) as the regression (R, n = 69) and nonregression (NR, n = 40) groups, respectively. RESULTS: Multivariate analyses revealed that the Ang-2 level at baseline and the Ang-2 level, albumin-bilirubin score, and FIB-4 index at 24 weeks after the EOT were significantly associated with regression of M2BPGi-based liver fibrosis. Receiver operating characteristic curve analyses showed that the Ang-2 level at 24 weeks after the EOT had the largest area under the curve values (0.859). The same results were obtained even when the serum M2BPGi levels were aligned by propensity score matching and in patients with advanced M2BPGi-based liver fibrosis: M2BPGi levels ≥3.3 COI at baseline. CONCLUSIONS: The serum Ang-2 level at 24 weeks after the EOT is a feasible predictor of regression of M2BPGi-based liver fibrosis after achieving SVR by DAA therapy.

Cytoplasmic delivery of siRNA using human-derived membrane penetration-enhancing peptide.

BACKGROUND: Although protein-based methods using cell-penetrating peptides such as TAT have been expected to provide an alternative approach to siRNA delivery, the low efficiency of endosomal escape of siRNA/protein complexes taken up into cells by endocytosis remains a problem. Here, to overcome this problem, we adopted the membrane penetration-enhancing peptide S19 from human syncytin 1 previously identified in our laboratory. RESULTS: We prepared fusion proteins in which the S19 and TAT peptides were fused to the viral RNA-binding domains (RBDs) as carrier proteins, added the RBD-S19-TAT/siRNA complex to human cultured cells, and investigated the cytoplasmic delivery of the complex and the knockdown efficiency of target genes. We found that the intracellular uptake of the RBD-S19-TAT/siRNA complex was increased compared to that of the RBD-TAT/siRNA complex, and the expression level of the target mRNA was decreased. Because siRNA must dissociate from RBD and bind to Argonaute 2 (Ago2) to form the RNA-induced silencing complex (RISC) after the protein/siRNA complex is delivered into the cytoplasm, a dilemma arises: stronger binding between RBD and siRNA increases intracellular uptake but makes RISC formation more difficult. Thus, we next prepared fusion proteins in which the S19 and TAT peptides were fused with Ago2 instead of RBD and found that the efficiencies of siRNA delivery and knockdown obtained using TAT-S19-Ago2 were higher than those using TAT-Ago2. In addition, we found that the smallest RISC delivery induced faster knockdown than traditional siRNA lipofection, probably due to the decreased time required for RISC formation in the cytoplasm. CONCLUSION: These results indicated that S19 and TAT-fused siRNA-binding proteins, especially Ago2, should be useful for the rapid and efficient delivery of siRNA without the addition of any endosome-disrupting agent.

Genetic Recombination Sites Away from the Insertion/Deletion Hotspots in SARS-Related Coronaviruses.

The genome sequences of severe acute respiratory syndrome (SARS)-related coronaviruses (sarbecoviruses) have been reported to include many long and complex insertions/deletions (indels) in specific genomic regions, including open reading frame 1a (ORF1a), S1 domain of the spike, and ORF8 genes. These indel hotspots incorporate various non-classical, long, and complex indels with uncertain developmental processes. A possible explanation for these complex and diversified indels at the hotspots is genetic recombination. To determine the possible association between recombination events and development of indel hotspots, this study investigated the genome sequences of many sarbecoviruses from different countries and hosts and compared the distributions of the indel hotspots and recombination sites by performing multiple sequence alignments and recombination analyses. The genomes of 19 SARS-related coronaviruses (15 coronaviruses that infect bats, two that infect humans, one that infects pangolins, and one that infects civets), including human-infecting SARS-CoV and SARS-CoV-2, were evaluated. Hotspots of complex indels with diverse RNA sequences around gaps were clustered in non-structural protein 2 (Nsp2) and Nsp3 of ORF1a, S1, and ORF8. Phylogenetic reconstructions revealed different structures of the inferred phylogenetic trees between genomic regions, and recombination analyses identified multiple recombination sites across ORF1ab and S genes. However, the nucleotide positions of the indel hotspots were not identical with the identified recombination sites in the recombinant viruses, suggesting the involvement of different developmental processes of indel hotspots and genetic recombination. Further research is required to elucidate the developmental mechanisms underpinning clustered complex indels and recombination events in the evolutionary history of sarbecoviruses.