Sphingolipid metabolites as potential circulating biomarkers for sarcopenia in men.

BACKGROUND: Sarcopenia is an age-related progressive loss of muscle mass and function. Sarcopenia is a multifactorial disorder, including metabolic disturbance; therefore, metabolites may be used as circulating biomarkers for sarcopenia. We aimed to investigate potential biomarkers of sarcopenia using metabolomics. METHODS: After non-targeted metabolome profiling of plasma from mice of an aging mouse model of sarcopenia, sphingolipid metabolites and muscle cells from the animal model were evaluated using targeted metabolome profiling. The associations between sphingolipid metabolites identified from mouse and cell studies and sarcopenia status were assessed in men in an age-matched discovery (72 cases and 72 controls) and validation (36 cases and 128 controls) cohort; women with sarcopenia (36 cases and 36 controls) were also included as a discovery cohort. RESULTS: Both non-targeted and targeted metabolome profiling in the experimental studies showed an association between sphingolipid metabolites, including ceramides (CERs) and sphingomyelins (SMs), and sarcopenia. Plasma SM (16:0), CER (24:1), and SM (24:1) levels in men with sarcopenia were significantly higher in the discovery cohort than in the controls (all P < 0.05). There were no significant differences in plasma sphingolipid levels for women with or without sarcopenia. In men in the discovery cohort, an area under the receiver-operating characteristic curve (AUROC) of SM (16:0) for low muscle strength and low muscle mass was 0.600 (95% confidence interval [CI]: 0.501-0.699) and 0.647 (95% CI: 0.557-0.737). The AUROC (95% CI) of CER (24:1) and SM (24:1) for low muscle mass in men was 0.669 (95% CI: 0.581-0.757) and 0.670 (95% CI: 0.582-0.759), respectively. Using a regression equation combining CER (24:1) and SM (16:0) levels, a sphingolipid (SphL) score was calculated; an AUROC of the SphL score for sarcopenia was 0.712 (95% CI: 0.626-0.798). The addition of the SphL score to HGS significantly improved the AUC from 0.646 (95% CI: 0.575-0.717; HGS only) to 0.751 (95% CI: 0.671-0.831, P = 0.002; HGS + SphL) in the discovery cohort. The predictive ability of the SphL score for sarcopenia was confirmed in the validation cohort (AUROC = 0.695, 95% CI: 0.591-0.799). CONCLUSIONS: SM (16:0), reflecting low muscle strength, and CER (24:1) and SM (16:0), reflecting low muscle mass, are potential circulating biomarkers for sarcopenia in men. Further research on sphingolipid metabolites is required to confirm these results and provide additional insights into the metabolomic changes relevant to the pathogenesis and diagnosis of sarcopenia.

Engineered lipid nanoparticles enable therapeutic gene silencing of GTSE1 for the treatment of liver fibrosis.

Liver fibrosis is characterized by abnormal accumulation of extracellular matrix proteins, disrupting normal liver function. Despite its significant health impact, effective treatments remain limited. Here, we present the development of engineered lipid nanoparticles (LNPs) for targeted RNA therapeutic delivery in the liver. We investigated the therapeutic potential of modulating the G2 and S-phase expressed 1 (GTSE1) protein for treating liver fibrosis. Through screening, we identified P138Y LNP as a potent candidate with superior delivery efficiency and lower toxicity. Using these engineered LNPs, we successfully delivered siGTSE1 to hepatocytes, significantly reducing collagen accumulation and restoring liver function in a fibrosis animal model. Additionally, GTSE1 downregulation altered miRNA expression and upregulated hepatocyte nuclear factor 4 alpha (HNF4α). These findings suggest that therapeutic gene silencing of GTSE1 is a promising strategy for treating liver fibrosis by regenerating liver phenotypes and functions.

Prognosis Following Sustained Virologic Response in Korean Chronic Hepatitis C Patients Treated with Sofosbuvir-Based Treatment: Data from a Multicenter Prospective Observational Study up to 7 Years.

Background and Objectives: Chronic hepatitis C (CHC) can be cured with direct-acting antiviral (DAA) therapy. In Korea, sofosbuvir (SOF) and ledipasvir (LDV)/SOF were launched in 2016. Patients who achieve a sustained virologic response (SVR) following DAA treatment are predicted to have a favorable prognosis. Nevertheless, little is known regarding the prognosis of Korean CHC patients who receive SOF-based treatment and achieve SVR. Therefore, the purpose of this study was to look into the long-term outcomes for these patients. Materials and Methods: This was a prospective, multicenter observational study. CHC patients were enrolled who, following SOF or LDV/SOF treatment, had achieved SVR. The last day for follow-up was December 2023. The primary endpoint was HCC occurrence, which was checked at least once per year. Results: A total of 516 patients were included in this analysis, with a median follow-up duration of 39.0 months. Among them, 231 were male patients (44.8%), with a median age of 62.0 years. Genotypes were 1 (90, 17.4%), 2 (423, 82.0%), and 3 (3, 0.6%). The combination of SOF plus ribavirin was the most common treatment (394, 76.4%). In total, 160 patients were cirrhotic (31.0%), and the mean Child-Pugh score was 5.1. Within a maximum of 7 years, 21 patients (4.1%) developed HCC. Patients with HCC were older (69 vs. 61 years, p = 0.013) and had a higher cirrhosis incidence (81.0 vs. 28.9%, p < 0.001), higher AFP (6.0 vs. 3.3, p = 0.003) and higher APRI (0.8 vs. 0.5, p = 0.005). Age over 65 (p = 0.016) and cirrhosis (p = 0.005) were found to be significant risk factors for HCC by Cox regression analysis. Conclusions: Patients who achieved SVR with SOF-based treatment had a relatively favorable prognosis. However, the risk of HCC was not eliminated, especially in older and cirrhotic patients. Therefore, routine follow-up, surveillance, and early treatment are required.

CX 3 CR1 + macrophages interact with HSCs to promote HCC through CD8 + T-cell suppression.

BACKGROUND AND AIMS: HSCs contribute to HCC progression by regulating multiple factors. However, the entire immunoregulatory functions of HSCs are still obscure. Here, we aim to investigate whether HSCs impose CX 3 CR1 + macrophages to protumorigenic properties in the peritumoral area. APPROACH AND RESULTS: In single-cell RNA-sequencing analysis of patients with HCC, a subpopulation of macrophages specifically expressed Arg1 and Cx3cr1 in the peritumoral area and were highly enriched with retinol metabolism-related genes. Flow cytometry analysis showed significantly increased frequencies of CD14 + CD11b + HLA-DR - macrophages with CX 3 CR1 in the HCC adjacent region where α-smooth muscle actin-expressing activated hepatic stellate cells (aHSCs) showed colocalized expression of CX 3 CL1. Accordingly, in tumor-bearing mice, Cx3cl1 mRNA expression was notably increased in aHSCs within the adjacent HCC, where infiltration of CX 3 CR1 + Ly6C + macrophages was mostly observed with decreased CD8 + T cells. In adoptive transfer and in vitro coculture of myeloid cells, we demonstrated that CX 3 CR1 + Ly6C + macrophages migrated and highly expressed arginase-1 by interacting with retinoid-enriched aHSCs in the adjacent HCC. Direct treatment of retinoids or coculturing with retinol-storing mouse aHSCs or human LX-2 cells significantly increased arginase-1 expression in CX 3 CR1 + Ly6C + macrophages and human blood CD14 + cells, leading to the suppression of CD8 + T-cell proliferation. Moreover, genetic deficiency of CX 3 CR1 in myeloid cells or pharmacological inhibition of retinol metabolism remarkably attenuated HCC development. CONCLUSIONS: We showed that CX 3 CR1 + Ly6C + macrophages migrate and interact with aHSCs in the peritumoral region where retinoids induce arginase-1 expression in CX 3 CR1 + Ly6C + macrophages, subsequently depriving CD8 + T cells of arginine and promoting HCC.

Protective Effects of the Postbiotic Levilactobacillus brevis BK3 against H2O2-Induced Oxidative Damage in Skin Cells.

Postbiotics have various functional effects, such as antioxidant, anti-inflammatory, and anti-obesity. Levilactobacillus brevis BK3, the subject of this study, was derived from lactic acid bacteria isolated from Kimchi, a traditional Korean fermented food. The antioxidant activity of BK3 was confirmed through the measurements of 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and total antioxidant capacity (TAC). The wrinkle improvement effect was validated by assessing elastase inhibitory activity and collagenase inhibitory activity. The intracellular activity was confirmed using human keratinocytes (HaCaT) and human fibroblasts (HFF-1). BK3 protects skin cells from oxidative stress induced by H2O2 and reduces intracellular reactive oxygen species (ROS) production. In addition, the expressions of the antioxidant genes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were upregulated. Meanwhile, matrix metalloproteinase-1 (MMP-1) and collagen type I alpha 1 (COL1A1), involved in collagen degradation and synthesis, were significantly regulated. These results suggest the possibility of utilizing BK3 as a functional ingredient with antioxidant and wrinkle-improving effects.

The role of glial and neuronal Eph/ephrin signaling in Drosophila mushroom body development and sleep and circadian behavior.

The Eph receptor, a prototypically large receptor protein tyrosine kinase, interacts with ephrin ligands, forming a bidirectional signaling system that impacts diverse brain functions. Eph receptors and ephrins mediate forward and reverse signaling, affecting neurogenesis, axon guidance, and synaptic signaling. While mammalian studies have emphasized their roles in neurogenesis and synaptic plasticity, the Drosophila counterparts are less studied, especially in glial cells, despite structural similarities. Using RNAi to modulate Eph/ephrin expression in Drosophila neurons and glia, we studied their roles in brain development and sleep and circadian behavior. Knockdown of neuronal ephrin disrupted mushroom body development, while glial knockdown had minimal impact. Surprisingly, disrupting ephrin in neurons or glial cells altered sleep and circadian rhythms, indicating a direct involvement in these behaviors independent from developmental effects. Further analysis revealed distinct sleep phenotypes between neuronal and glial knockdowns, underscoring the intricate interplay within the neural circuits that govern behavior. Glia-specific knockdowns showed altered sleep patterns and reduced circadian rhythmicity, suggesting an intricate role of glia in sleep regulation. Our findings challenge simplistic models of Eph/ephrin signaling limited to neuron-glia communication and emphasize the complexity of the regulatory networks modulating behavior. Future investigations targeting specific glial subtypes will enhance our understanding of Eph/ephrin signaling's role in sleep regulation across species.

ERG activates a stem-like proliferation-differentiation program in prostate epithelial cells with mixed basal-luminal identity.

To gain insight into how ERG translocations cause prostate cancer, we performed single cell transcriptional profiling of an autochthonous mouse model at an early stage of disease initiation. Despite broad expression of ERG in all prostate epithelial cells, proliferation was enriched in a small, stem-like population with mixed-luminal basal identity (called intermediate cells). Through a series of lineage tracing and primary prostate tissue transplantation experiments, we find that tumor initiating activity resides in a subpopulation of basal cells that co-express the luminal genes Tmprss2 and Nkx3.1 (called BasalLum) but not in the larger population of classical Krt8+ luminal cells. Upon ERG activation, BasalLum cells give rise to the highly proliferative intermediate state, which subsequently transitions to the larger population of Krt8+ luminal cells characteristic of ERG-positive human cancers. Furthermore, this proliferative population is characterized by an ERG-specific chromatin state enriched for NFkB, AP-1, STAT and NFAT binding, with implications for TF cooperativity. The fact that the proliferative potential of ERG is enriched in a small stem-like population implicates the chromatin context of these cells as a critical variable for unmasking its oncogenic activity.

A novel A2a adenosine receptor inhibitor effectively mitigates hepatic fibrosis in a metabolic dysfunction-associated steatohepatitis mouse model.

Hepatic fibrosis exacerbates mortality and complications in progressive metabolic dysfunction-associated steatohepatitis (MASH). The role of the adenosine 2A receptor (A2aAR) in hepatic fibrosis within the context of MASH remains uncertain. This study aims to elucidate the involvement of the A2aAR signaling pathway and the efficacy of a novel potent A2aAR antagonist in treating hepatic fibrosis in MASH-induced mice fed a chlorine-deficient, L-amino acid-defined, high fat diet (CDAHFD). A2aAR overexpression in LX-2 cells increased fibrosis markers, whereas the known A2aAR antagonist, ZM241385, decreased these markers. A novel A2aAR antagonist, RAD11, not only attenuated fibrosis progression but also exhibited greater inhibition of the A2aAR signaling pathway compared to ZM241385 in mice with MASH, activated primary hepatocytes, and LX-2 cells. RAD11 exhibited a dual antifibrotic mechanism by targeting both activated HSCs and hepatocytes. Its superior antifibrotic efficacy over ZM241385 in the MASH condition stems from its ability to suppress A2aAR-mediated signaling, inhibit HSC activation, reduce hepatic lipogenesis in hepatocytes, and mitigate lipid accumulation-induced oxidative stress-mediated liver damage. This study has shed light on the relationship between A2aAR signaling and hepatic fibrosis, presenting RAD11 as a potent therapeutic agent for managing MASH and hepatic fibrosis.

First detection and characterization of hepatitis E virus (Rocahepevirus ratti) from urban Norway rats (Rattus norvegicus) in the Republic of Korea.

Hepatitis E virus (HEV), an emerging zoonotic pathogen, poses a significant public health concern worldwide. Recently, rat HEV (Rocahepevirus ratti genotype C1; HEV-C1) has been reported to cause zoonotic infections and hepatitis in humans. Human infections with HEV-C1 are considered to be underestimated worldwide due to limited knowledge of transmission routes, genome epidemiology, and the risk assessment of zoonosis associated with these viruses. A total of 186 wild Norway rats (Rattus norvegicus) were collected from the Republic of Korea (ROK) between 2011 and 2021. The prevalence of HEV-C1 RNA was 8 of 180 (4.4%) by reverse-transcription polymerase chain reaction. We first reported three nearly whole-genome sequences of HEV-C1 newly acquired from urban rats in the ROK. Phylogenetic analysis demonstrated that Korea-indigenous HEV-C1 formed an independent genetic group with those derived from R. norvegicus rats in other countries, indicating geographical and genetic diversity. Our findings provide critical insights into the molecular prevalence, genome epidemiology, and zoonotic potential of Rocahepevirus. This report raises awareness of the presence of Rocahepevirus-related hepatitis E among physicians in the ROK.

Noninferiority Outcomes of Besifovir Compared to Tenofovir Alafenamide in Treatment-Naïve Patients with Chronic Hepatitis B.

Background/Aims: : Besifovir dipivoxil maleate (BSV) and tenofovir alafenamide fumarate (TAF) have been recently approved in Korea as the initial antiviral agents for chronic hepatitis B (CHB). However, the real-world outcome data for these drugs remain limited. Therefore, we conducted a noninferiority analysis using real-world data to compare the clinical outcomes of the two nucleotide analogs in treatment-naïve patients with CHB. Methods: : We retrospectively investigated a cohort of patients with CHB who received BSV or TAF as first-line antiviral agents. The endpoints were virological response (VR) and liver-related clinical outcomes. Results: : A total of 537 patients, consisting of 202 and 335 patients administered BSV and TAF, respectively, were followed up for 42 months. No significant difference was observed between the VRs of the patients from the two groups. The rates of biochemical response, virologic breakthrough, and incidence rates of hepatocellular carcinoma did not differ between the groups. However, the hepatitis B e antigen seroclearance rate was higher and the renal function declined less in the BSV group. Multivariable analysis indicated older age, alcohol abuse, cirrhosis and ascites, and lower serum HBV DNA level to be independently associated with increased hepatocellular carcinoma risk. The 1:1 propensity score-matched analysis with 400 patients showed VR rates of 85.0% and 88.7% in the BSV and TAF group patients, respectively, at 2 years. The absolute value of the 95% confidence interval for the difference (-0.04 to 0.12) satisfied the a priori limit of a noninferiority of 0.15. Conclusions: : BSV is noninferior to TAF in terms of VR, and their clinical outcomes are comparable to CHB.

Effects of host-associated low-temperature probiotics in olive flounder (Paralichthys olivaceus) aquaculture.

This study investigated the effects of supplementation of low-temperature probiotics isolated from the intestines of olive flounder on the growth performance, digestibility, and regulation of intestinal microbiota and the expression of genes related to growth, immunity, and apoptosis in olive flounder. Bacteria showing high growth at approximately 15-20 °C, which is the temperature of olive flounder culture, were isolated and confirmed to be Pseudomonas species through 16S rRNA gene sequence analysis. Whole-genome sequencing revealed that the strain has a 6,195,122 bp single circular chromosome and a guanine-cytosine content of 59.9%. In the feeding trial, supplementation with 1 × 108 CFU/g of the isolate strain positively modulated growth performances, digestive enzyme activity, and gut microbiota composition of olive flounder. RT-qPCR for the comparison of growth, immunity, and apoptosis-related gene expression levels showed no significant differences between the groups. Therefore, the isolated host-associated low-temperature probiotics improved the growth performance of olive flounder by causing positive changes in digestive activity and intestinal microbial composition without affecting host gene expression.

Combination of Host-Associated Rummeliibacillus sp. and Microbacterium sp. Positively Modulated the Growth, Feed Utilization, and Intestinal Microbial Population of Olive Flounder (Paralichthys olivaceus).

Two novel strains of Rummeliibacillus sp. and Microbacterium sp. were identified from the intestine of olive flounder (Paralichthys olivaceus) and characterized in vitro as potential probiotics. Feeds without probiotic and with a 50:50 mixture of these two strains (1 × 108 CFU/g feed) were denoted as the control and Pro diets, respectively. Three randomly selected tanks (20 flounders/tank, ~11.4 g each) were used for each diet replication. After 8 weeks of feeding, the growth and feed utilization of the flounder in the Pro group improved (p < 0.05) compared to the control. Among four immune parameters, only myeloperoxidase activity was elevated in the Pro group. Serum biochemistry, intestinal microbial richness (Chao1), and diversity (Shannon index) remained unchanged (p ≥ 0.05), but phylogenetic diversity was enriched in the Pro fish intestine. Significantly lower Firmicutes and higher Proteobacteria were found in the Pro diet; the genus abundance in the control and Pro was as follows: Staphylococcus > Lactobacillus > Corynebacterium and Lactobacillus > Staphylococcus > Corynebacterium, respectively. Microbial linear discriminant scores and a cladogram analysis showed significant modulation. Therefore, the combination of two host-associated probiotics improved the growth and intestinal microbial population of flounder and could be supplemented in the Korean flounder industry.

Prognosis of Patients with Chronic Hepatitis C Genotype 1b Infection Treated Using Daclatasvir/Asunaprevir after Sustained Virologic Response: A 6-Year Multicenter Prospective Observational Study.

Aim and Objectives: Direct-acting antiviral (DAA) therapy can cure chronic hepatitis C (CHC), and daclatasvir (DCV)/asunaprevir (ASV) was the first interferon-free DAA therapy introduced in Korea. Patients who achieve sustained virologic response (SVR) after DAA treatment are expected to have good prognoses. Therefore, in this study, we aimed to investigate the prognosis of these patients. Materials and Methods: This multicenter prospective observational study included patients with CHC who achieved SVR after DCV/ASV treatment. The primary endpoint was hepatocellular carcinoma (HCC) occurrence, which was reviewed annually. Results: We included 302 patients (median follow-up duration: 38 [16.5-60.0] months; median age: 58 [49-67] years) in the study. Cirrhosis was observed in 103 patients (34.1%), and the median Child-Pugh score was 5.0. HCC occurred in 16 patients (5.3%) within six years post-SVR; these patients were older and had higher cirrhosis prevalence, alpha-fetoprotein levels, and fibrosis-4 index scores than did those without HCC development. Cox proportional hazards analysis revealed that age > 71 years (p = 0.005) and cirrhosis (p = 0.035) were significant risk factors for HCC occurrence. Conclusions: Although the prognoses of patients who achieved SVR with DCV/ASV therapy were generally good, the risk for HCC was present, especially in older patients and in those with cirrhosis. Hence, early treatment at younger ages and regular follow-up surveillance after achieving SVR are warranted.

Molecular diagnosis of patients with hepatitis A virus infection using amplicon-based nanopore sequencing.

High-throughput sequencing is a robust tool used for identifying and tracking pathogen outbreaks. Whole-genome sequencing of hepatitis A virus (HAV) remains poor due to ultra-low viral loads, limitations of next-generation sequencing technology, and its high costs in clinical applications. This study evaluated multiplex polymerase chain reaction (PCR)-based nanopore sequencing to obtain whole-genome sequences of HAV. The HAV genomes were obtained directly from patient specimens for a rapid molecular diagnosis of viral genotypes. Serum and stool samples were collected from six patients with hepatitis A infection. Amplicon-based nanopore sequencing was performed from the clinical specimens to identify HAV genotypes by acquiring nearly complete-genome sequences. TaqMan-based quantitative PCR (qPCR) was conducted to detect and quantify multiple HAV genes. Singleplex-based nanopore sequencing demonstrated high genome coverage rates (90.4-99.5%) of HAV within 8 h, at viral RNA loads of 10 to 105 copies/µL. TaqMan qPCR showed multiplex quantification of HAV genes namely, VP0, VP3, and 3C. This study provides useful insights into rapid molecular diagnosis during hepatitis A outbreaks and may ultimately augment public health disease surveillance in the hospital and epidemiology field.

Aortic carboxypeptidase-like protein, a putative myokine, stimulates the differentiation and survival of bone-forming osteoblasts.

A new target that stimulates bone formation is needed to overcome limitations of current anti-osteoporotic drugs. Myokines, factors secreted from muscles, may modulate it. In this study, we investigated the role of aortic carboxypeptidase-like protein (ACLP), which is highly expressed in skeletal muscles, on bone formation. MC3T3-E1 cells and/or calvaria osteoblasts were treated with recombinant N-terminal mouse ACLP containing a signal peptide [rmACLP (N)]. The expression and secretion of ACLP were higher in skeletal muscle and differentiated myotube than in other tissues and undifferentiated myoblasts, respectively. rmACLP (N) increased bone formation, ALP activity, and phosphorylated p38 mitogen-activated protein (MAP) kinase in osteoblasts; reversal was achieved by pre-treatment with a TGF-ß receptor inhibitor. Under H2 O2 treatment, rmACLP (N) increased osteoblast survival, phosphorylated p38 MAP kinase, and the nuclear translocation of FoxO3a in osteoblasts. H2 O2 treatment caused rmACLP (N) to suppress its apoptotic, oxidative, and caspase-9 activities. rmACLP (N)-stimulated osteoblast survival was reversed by pre-treatment with a p38 inhibitor, a TGF-ß-receptor II blocking antibody, and a FoxO3a shRNA. Conditioned media (CM) from muscle cells stimulated osteoblast survival under H2 O2 treatment, in contrast to CM from ACLP knockdown muscle cells. rmACLP (N) increased the expressions of FoxO3a target anti-oxidant genes such as Sod2, Trx2, and Prx5. In conclusion, ACLP stimulated the differentiation and survival of osteoblasts. This led to the stimulation of bone formation by the activation of p38 MAP kinase and/or FoxO3a via TGF-ß receptors. These findings suggest a novel role for ACLP in bone metabolism as a putative myokine.

Recent advances in endocrine organoids for therapeutic application.

The endocrine system, consisting of the hypothalamus, pituitary, endocrine glands, and hormones, plays a critical role in hormone metabolic interactions. The complexity of the endocrine system is a significant obstacle to understanding and treating endocrine disorders. Notably, advances in endocrine organoid generation allow a deeper understanding of the endocrine system by providing better comprehension of molecular mechanisms of pathogenesis. Here, we highlight recent advances in endocrine organoids for a wide range of therapeutic applications, from cell transplantation therapy to drug toxicity screening, combined with development in stem cell differentiation and gene editing technologies. In particular, we provide insights into the transplantation of endocrine organoids to reverse endocrine dysfunctions and progress in developing strategies for better engraftments. We also discuss the gap between preclinical and clinical research. Finally, we provide future perspectives for research on endocrine organoids for the development of more effective treatments for endocrine disorders.

In Vivo and In Vitro Models to Study Liver Fibrosis: Mechanisms and Limitations.

Liver fibrosis is a common result of liver injury owing to various kinds of chronic liver diseases. A deeper understanding of the pathophysiology of liver fibrosis and identifying potential therapeutic targets of liver fibrosis is important because liver fibrosis may progress to advanced liver diseases, such as cirrhosis and hepatocellular carcinoma. Despite numerous studies, the underlying mechanisms of liver fibrosis remain unclear. Mechanisms of the development and progression of liver fibrosis differ according to etiologies. Therefore, appropriate liver fibrosis models should be selected according to the purpose of the study and the type of underlying disease. Many in vivo animal and in vitro models have been developed to study liver fibrosis. However, there are no perfect preclinical models for liver fibrosis. In this review, we summarize the current in vivo and in vitro models for studying liver fibrosis and highlight emerging in vitro models, including organoids and liver-on-a-chip models. In addition, we discuss the mechanisms and limitations of each model.

Exosomes: Nomenclature, Isolation, and Biological Roles in Liver Diseases.

The biogenesis and biological roles of extracellular vesicles (EVs) in the progression of liver diseases have attracted considerable attention in recent years. EVs are membrane-bound nanosized vesicles found in different types of body fluids and contain various bioactive materials, including proteins, lipids, nucleic acids, and mitochondrial DNA. Based on their origin and biogenesis, EVs can be classified as apoptotic bodies, microvesicles, and exosomes. Among these, exosomes are the smallest EVs (30-150 nm in diameter), which play a significant role in cell-to-cell communication and epigenetic regulation. Moreover, exosomal content analysis can reveal the functional state of the parental cell. Therefore, exosomes can be applied to various purposes, including disease diagnosis and treatment, drug delivery, cell-free vaccines, and regenerative medicine. However, exosome-related research faces two major limitations: isolation of exosomes with high yield and purity and distinction of exosomes from other EVs (especially microvesicles). No standardized exosome isolation method has been established to date; however, various exosome isolation strategies have been proposed to investigate their biological roles. Exosome-mediated intercellular communications are known to be involved in alcoholic liver disease and nonalcoholic fatty liver disease development. Damaged hepatocytes or nonparenchymal cells release large numbers of exosomes that promote the progression of inflammation and fibrogenesis through interactions with neighboring cells. Exosomes are expected to provide insight on the progression of liver disease. Here, we review the biogenesis of exosomes, exosome isolation techniques, and biological roles of exosomes in alcoholic liver disease and nonalcoholic fatty liver disease.

Diagnostic Efficacy of Serum Asialo α1-Acid Glycoprotein Levels for Advanced Liver Fibrosis and Cirrhosis in Patients with Chronic Hepatitis B Compared to That in Healthy Subjects: A Prospective Study.

Background: Serum asialo α1-acid gycoprotein (AsAGP) is a novel biomarker specific to liver fibrosis. Aim: To evaluate the diagnostic efficacy of serum AsAGP levels in classifying the severity of liver fibrosis and differentiating liver cirrhosis (LC) in patients with chronic hepatitis B (CHB) from healthy controls. Methods: Overall, 206 subjects were prospectively enrolled. LC was diagnosed based on liver stiffness levels (>11 kPa) measured using transient elastography. Serum AsAGP levels were measured using an antibody-lectin sandwich immunoassay. We investigated the diagnostic performance by comparing serum AsAGP levels among healthy control, CHB, and CHB with LC groups. Sensitivity, specificity, and optimal AsAGP cut-off values were also calculated. Results: Serum AsAGP levels were significantly different between healthy controls, CHB patients, and CHB patients with LC (1.04 ± 0.31 µg/mL, 1.12 ± 0.34 µg/mL, 1.51 ± 0.43 µg/mL respectively; p < 0.001). Serum AsAGP levels positively correlated with liver stiffness (r = 0.46, p < 0.001). AUROC of healthy control versus CHB with LC was 0.821 (p < 0.001, optimal cut-off 1.036 µg/mL). AUROC of healthy control versus CHB was 0.624 (p = 0.049, optimal cut-off level 0.934 µg/mL). AUROC of CHB versus CHB with LC was 0.765, (p < 0.001, optimal cut-off 1.260 µg/mL). Conclusions: Serum AsAGP levels in CHB patients with LC were significantly higher than those in healthy controls and CHB patients. AsAGP levels showed good diagnostic performance in predicting advanced fibrosis and cirrhosis, which suggests a potential role as a biomarker for predicting the progression of liver disease in CHB.

The clinical effect of antiviral therapy in patients with hepatitis B virus-related decompensated cirrhosis and undetectable DNA.

BACKGROUND AND AIM: Antiviral therapy (AVT) is the mainstay of hepatitis B virus (HBV) management. We investigated whether AVT improves the outcomes of HBV-related decompensated cirrhosis and undetectable HBV-DNA. METHODS: Between 2000 and 2017, treatment-naïve patients with HBV-related decompensated cirrhosis and undetectable HBV-DNA were recruited from two tertiary hospitals. The endpoints included death and hepatocellular carcinoma (HCC). RESULTS: A total of 429 patients were analyzed (50 and 379 patients in the AVT and non-AVT groups, respectively). Patients in the AVT group were significantly younger and had higher alanine aminotransferase and alpha-fetoprotein levels than those in the non-AVT group (all P < 0.05). During follow-up (median 49.6 months), 98 patients died and 105 developed HCC. The cumulative incidence rates of death (2.0%, 4.1%, and 6.4%, and 4.9%, 7.2%, and 10.2% at 6 months, 1 year, and 2 years, respectively) and HCC (8.6%, 15.8%, and 26.4% vs 1.6%, 7.7%, and 24.4% at 1, 2, and 5 years, respectively) were statistically comparable between the AVT and non-AVT groups (all P > 0.05). Using Cox regression analysis, AVT was not significantly associated with death nor HCC (all P > 0.05). Similar results were observed after balancing baseline characteristics with inverse probability of treatment weighting. In the non-AVT group, the cumulative incidence rates of HBV-DNA detection at 6 months, 1 year, and 2 years were 2.0%, 3.1%, and 6.4%, respectively. CONCLUSIONS: Antiviral therapy did not attenuate the risk of death nor HCC in patients with HBV-related decompensated cirrhosis and undetectable HBV-DNA.