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Background and Aim: The purpose of this study was to analyze factors associated with the overall survival (OS) of atezolizumab/bevacizumab combination therapy for advanced hepatocellular carcinoma (aHCC). We also assessed the OS of patients with ineffective therapy and those who discontinued treatment owing to adverse events (AEs)., Methods: This retrospective multicenter study involved 139 patients with aHCC who received atezolizumab/bevacizumab combination therapy between November 2020 and September 2022., Results: The median duration of treatment was 136.5 days, and the median observation period was 316 days. The overall response rate was 40%, and the disease control rate was 78% according to mRECIST criteria. Grade ≥2 AEs occurred in 63 patients (43%) and led to treatment discontinuation in 16 patients. Multivariate analysis revealed that treatment response and occurrence of grade ≥2 AEs after therapy, as well as low level of albumin-bilirubin (ALBI) grade and low level of des-gamma carboxy prothrombin (DCP) before therapy, were extracted as factors that contributed to OS. Log-rank tests with the Kaplan-Meier method showed significant differences in OS among these factors. The OS of patients who discontinued owing to AEs was significantly shorter than that of other patients., Conclusion: Not only factors before therapy but also treatment response and the appearance of AEs are involved in OS for atezolizumab/bevacizumab combination therapy. Although the development of AEs also contributed to OS, appropriate management of AEs is important to avoid discontinuing treatment with this combination., (© 2023 The Authors. JGH Open published by Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background and Aim: Molecular-targeted therapies such as sorafenib and lenvatinib have long been used as first-line treatment for advanced hepatocellular carcinoma (aHCC). However, adverse events or limited therapeutic effects may necessitate the change to another therapeutic option, known as post-progression therapy. To investigate the significance of post-progression therapy, we analyzed the outcomes of aHCC patients following first-line molecular-targeted therapy in a real-world study., Methods: This retrospective, multicenter study involved patients with aHCC who received sorafenib or lenvatinib as first-line therapy between January 2011 and September 2021., Results: In total, 513 patients were analyzed: 309 treated with sorafenib and 204 with lenvatinib. The overall response and disease control rates were 15 and 50%, respectively, in the sorafenib group and 30 and 75%, respectively, in the lenvatinib group ( P  < 0.001). Kaplan-Meier analysis revealed no significant differences in progression-free survival and overall survival (OS) between the two treatments. Multivariate analysis revealed that fibrosis-4 index, disease control rate, post-progression therapy, and use of an immune checkpoint inhibitor (ICI) were significantly associated with OS. OS was significantly longer in patients who received post-progression therapy than in those who did not (log-rank P  < 0.001). Most patients who received an ICI as post-progression therapy had previously received lenvatinib. Among lenvatinib-treated patients, OS was significantly longer in patients who received an ICI than in patients received another or no post-progression therapy ( P  = 0.004)., Conclusion: The introduction of newer drugs for post-progression therapy is expected to prolong survival. ICI-based regimens appear to be effective after lenvatinib., (© 2022 The Authors. JGH Open published by Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Resistant starch (RS) has been reported to improve steatosis as well as obesity. Type 4 resistant starch (RS4), a chemically modified starch, is particularly hard to digest and suggesting higher efficacy. However, because the effects of RS4 on steatosis are not yet fully understood, the effects of RS4 on steatosis were examined using a murine high-fat diet model. Seven-week-old male mice were divided into three groups and fed a normal diet, a high-fat diet (HFD), or a high-fat diet with added RS (HFD + RS). Amylofiber SH ® produced from acid-treated corn starch was used as the dietary RS. At 22 weeks old, hepatic steatosis and short chain fatty acid (SCFA) content and gut microbiota in cecum stool samples were analyzed. The ratio of body weight to 7 weeks was significantly suppressed in the HFD + RS group compared to the HFD group (132.2 ± 1.4% vs. 167.2 ± 3.9%, p = 0.0076). Macroscopic and microscopic steatosis was also suppressed in the HFD + RS group. Analysis of cecum stool samples revealed elevated SCFA levels in the HFD + RS group compared with the HFD group. Metagenome analysis revealed that Bifidobacterium (17.9 ± 1.9% vs. 3.6 ± 0.7%, p = 0.0019) and Lactobacillus (14.8 ± 3.4% vs. 0.72 ± 0.23%, p = 0.0045), which degrade RS to SCFA, were more prevalent in the HFD + RS group than the HFD group. In conclusion, RS4 suppressed steatosis, and increased Bifidobacterium and Lactobacillus, and SCFAs. RS4 may prevent steatosis by modulating the intestinal environment., (© 2022 Institute of Food Technologists®.)

Catabolic conditions, such as starvation, inactivity, and cancer cachexia, induce Forkhead box O (FOXO) transcription factor(s) expression and severe muscle atrophy via the induction of ubiquitin-proteasome system-mediated muscle proteolysis, resulting in frailty and poor quality of life. Although FOXOs are clearly essential for the induction of muscle atrophy, it is unclear whether there are other factors involved in the FOXO-mediated transcriptional regulation. As such, we identified FOXO-CCAAT/enhancer-binding protein δ (C/EBPδ) signaling pathway as a novel proteolytic pathway. By comparing the gene expression profiles of FOXO1-transgenic (gain-of-function model) and FOXO1,3a,4 -/- (loss-of-function model) mice, we identified several novel FOXO1-target genes in skeletal muscle including Redd1, Sestrin1, Castor2, Chac1, Depp1, Lat3, as well as C/EBPδ. During starvation, C/EBPδ abundance was increased in a FOXOs-dependent manner. Notably, knockdown of C/EBPδ prevented the induction of the ubiquitin-proteasome system and decrease of myofibers in FOXO1-activated myotubes. Conversely, C/EBPδ overexpression in primary myotubes induced myotube atrophy. Furthermore, we demonstrated that FOXO1 enhances the promoter activity of target genes in cooperation with C/EBPδ and ATF4. This research comprehensively identifies novel FOXO1 target genes in skeletal muscle and clarifies the pathophysiological role of FOXO1, a master regulator of skeletal muscle atrophy., (© 2022 Federation of American Societies for Experimental Biology.)

Purpose: The risk factors and clinical characteristics of ICI-induced immune-mediated hepatotoxicity (IMH) are not fully understood. Thus, the present study sought to clarify the clinical features of IMH., Methods: All patients treated with ICIs between September 2014 and April 2019 at our institution were included. Clinical data were retrospectively collected from medical records. The frequency of grade ≥ 2 liver damage, clinical characteristics, and risk factors for developing IMH were examined., Results: Overall, 250 patients (median age 71 years; range 30-87 years; 202 males and 48 females) were included in the analyses. Forty-five patients had elevated transaminase levels (> threefold the upper limit of normal). Of these, 21 were considered to have IMH. The remaining 24 patients had other causes of elevated transaminase levels. Steroids were administered to 13/21 patients with IMH. Although all patients exhibited improvement, IMH was not associated with the anticancer efficacy of the ICIs or OS. A multivariable analysis revealed that IMH was significantly associated with malignant melanoma (odds ratio [OR] 11.6; 95% confidence interval [CI] 3.5-38.0; P = 0.0002) and ipilimumab-nivolumab combination therapy (OR 61.2; 95% CI 7.9-1275.3; P < 0.0001)., Conclusion: Immune-mediated hepatotoxicity occurred in 9.5% of patients treated with ICIs. Appropriate therapeutic interventions are important to avoid affecting the patient's prognosis, and accurate diagnosis of IMH is essential for this purpose. The frequency of IMH varied according to the type of cancer and the drug used, and was significantly higher in patients with malignant melanoma and in patients given ipilimumab-nivolumab combination therapy.

Beta-catenin-activated hepatocellular adenoma is potentially malignant and warrants careful follow-up and surgical resection. Here, we report a 48-year-old man in whom a 55 mm single liver tumor was incidentally detected in the S1 segment. Contrast-enhanced computed tomography scans showed no enhancement in the early phase and a slight defection in the late phase. The tumor was enhanced hyperintensity in the hepatobiliary phase on Gd-ethoxybenzyl-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging. The histologic features of ultrasound-guided fine-needle aspiration biopsy indicated hepatocellular adenoma, and the tumor was immunohistochemically positive for glutamine synthetase and β-catenin. Considering the risk of malignant transformation, he underwent laparoscopic-assisted partial liver resection. The resected tumor did not contain any malignant lesions. This case indicates that aspiration needle biopsy and immunohistochemistry were useful for histological diagnosis and treatment decisions based on the molecular definition of hepatocellular adenoma.

An 80-year old man with myelofibrosis and chronic renal disease was admitted to our hospital because of severe anemia and gastrointestinal bleeding. Although no bleeding was observed by upper or lower endoscopy, contrast-enhanced computed tomography revealed an enhanced area in the small intestinal wall that was suspected of being the bleeding site, and was confirmed by double-balloon endoscopy. Based on endoscopic findings, it was difficult to differentiate between variceal rupture and collapse of a submucosal tumor. We performed segmental resection of the small intestine to make a definitive diagnosis and achieve reliable hemostasis. The gross findings confirmed a variceal rupture from the small intestine. His gastrointestinal bleeding stopped and his anemia improved following surgery. Although some cases of portal hypertension in association with myelofibrosis have been reported, we are aware of no prior reports of variceal rupture in the small intestine. To our knowledge, this is the first reported case of ectopic jejunal varices in a patient with myelofibrosis.

PGC-1α expression increases in skeletal muscles during exercise and regulates the transcription of many target genes. In this study, we conducted a metabolomic analysis on the blood of transgenic mice overexpressing PGC-1α in its skeletal muscle (PGC-1α-Tg mice) using CE-TOFMS. The blood level of homovanillic acid (dopamine metabolite) and the gene expression of dopamine metabolic enzyme in the skeletal muscle of PGC-1α-Tg mice were high. The blood level of 5-methoxyindoleacetic acid was also high in PGC-1α-Tg mice. The blood levels of branched-chain α-keto acids and β-alanine were low in PGC-1α-Tg mice. These metabolites in the skeletal muscle were present in low concentration. The changes in these metabolites may reflect the skeletal muscle condition with increasing PGC-1α, such as exercise., (© The Author(s) 2021. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

A 72-year-old man underwent transarterial chemoembolization (TACE) for solitary hepatocellular carcinoma (HCC) located on the S6 segment. He had a history of anti-viral therapy for hepatitis C virus and was being treated for diabetes mellitus with inadequate control. On day 28 after TACE, he visited our hospital again, with complaints of fever and abdominal pain in the right upper quadrant. Blood examination showed elevated levels of white blood cells and C-reactive protein. Computed tomography showed a poorly marginated, low-density lesion measuring 9.5 × 8.0 × 4.0 cm, forming multiple small gas bubbles, located superiorly, and in contact with HCC treated by TACE. Ultrasound-guided puncture revealed whiffy and muddy pus. Gram staining of the pus showed the presence of numerous gram-positive rods, which were identified as Cutibacterium namnetense. He underwent percutaneous trans-hepatic abscess drainage and received antibiotics treatment. The abscess was successfully treated, and he was discharged on day 19. The incidence of liver abscess after TACE is rare, and intestinal microbiota have been reported to be the common pathogens. To the best of our knowledge, this is the first case of liver abscess caused by Cutibacterium namnetense.

Peroxisome proliferator-activated receptor-gamma coactivator-1β (PGC-1β) is a transcriptional regulator whose increased expression activates energy expenditure-related genes in skeletal muscles. However, how PGC-1β is regulated remains largely unclear. Here, we show that PGC-1β gene expression is negatively correlated with the expression of a transcription factor, forkhead box protein O1 (FOXO1), whose expression is increased during muscle atrophy. In the skeletal muscles of FOXO1-overexpressing transgenic mice, PGC-1β gene expression is decreased. Denervation or plaster cast-based unloading, as well as fasting, increases endogenous FOXO1 expression in skeletal muscles, with decreased PGC-1β expression. In the skeletal muscles of FOXO1-knockout mice, the decrease in PGC-1β expression caused by fasting was attenuated. Tamoxifen-inducible FOXO1 activation in C2C12 myoblasts causes a marked decrease of PGC-1β expression. These findings together reveal that FOXO1 activation suppresses PGC-1β expression. During atrophy with FOXO1 activation, decreased PGC-1β may decrease energy expenditure and avoid wasting energy., (© 2020 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.)

Amino acids are components of proteins that also exist free-form in the body; their functions can be divided into (1) nutritional, (2) sensory, and (3) biological regulatory roles. The skeletal muscle, which is the largest organ in the human body, representing ~40% of the total body weight, plays important roles in exercise, energy expenditure, and glucose/amino acid usage-processes that are modulated by various amino acids and their metabolites. In this review, we address the metabolism and function of amino acids in the skeletal muscle. The expression of PGC1 α , a transcriptional coactivator, is increased in the skeletal muscle during exercise. PGC1 α activates branched-chain amino acid (BCAA) metabolism and is used for energy in the tricarboxylic acid (TCA) cycle. Leucine, a BCAA, and its metabolite, β -hydroxy- β -methylbutyrate (HMB), both activate mammalian target of rapamycin complex 1 (mTORC1) and increase protein synthesis, but the mechanisms of activation appear to be different. The metabolite of valine (another BCAA), β -aminoisobutyric acid (BAIBA), is increased by exercise, is secreted by the skeletal muscle, and acts on other tissues, such as white adipose tissue, to increase energy expenditure. In addition, several amino acid-related molecules reportedly activate skeletal muscle function. Oral 5-aminolevulinic acid (ALA) supplementation can protect against mild hyperglycemia and help prevent type 2 diabetes. β -alanine levels are decreased in the skeletal muscles of aged mice. β -alanine supplementation increased the physical performance and improved the executive function induced by endurance exercise in middle-aged individuals. Further studies focusing on the effects of amino acids and their metabolites on skeletal muscle function will provide data essential for the production of food supplements for older adults, athletes, and individuals with metabolic diseases.

Sarcopenia is the age-induced, progressive loss of skeletal muscle mass and function. To better understand changes in skeletal muscle during sarcopenia, we performed a metabolomic analysis of skeletal muscle in young (8-week-old) and aged (28-month-old) mice by using capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry. Principal component analysis showed clear changes in metabolites between young and aged mice. Glucose metabolism products were decreased in aged mice, specifically fructose 1,6-diphosphate (0.4-fold) and dihydroxyacetone phosphate (0.6-fold), possibly from decreased glycolytic muscle fibers. Multiple metabolic products associated with phospholipid metabolism were significantly changed in aged mice, which may reflect changes in cell membrane phospholipids of skeletal muscle. Products of polyamine metabolism, which are known to increase nucleic acid and protein synthesis, decreased in spermine (0.5-fold) and spermidine (0.6-fold) levels. By contrast, neurotransmitter levels were increased in skeletal muscle of aged mice, including acetylcholine (1.8-fold), histamine (2.6-fold), and serotonin (1.7-fold). The increase in acetylcholine might compensate for age-associated dropout of neuromuscular junctions, whereas the increases in histamine and serotonin might be due to muscle injury associated with aging. Further analysis focusing on the altered metabolites observed in this study will provide essential data for understanding aging muscles.

The transcription factor FOXO1 is considered to play roles in the regulation of energy metabolism in various tissues. To determine the metabolic changes occurring due to FOXO1 activation, we analyzed the metabolic profile of C2C12 myoblasts expressing a FOXO1-estrogen receptor fusion protein using capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry (CE-TOFMS). In FOXO1-activated cells, the metabolite levels during glycolysis are higher and the gene expression of pyruvate dehydrogenase kinase, an enzyme that inhibits glucose utilization, is increased. In addition, the metabolite levels of numerous amino acids are decreased, with increased gene expression of branched chain amino acid metabolism enzymes. Our results suggest that FOXO1 suppresses glucose utilization and promotes the use of proteins/amino acids as energy sources in muscle cells, potentially during starvation., (© 2019 Federation of European Biochemical Societies.)

PGC-1β is a transcriptional co-activator of nuclear receptors, which acts to increase energy expenditure. PGC-1β fused to GAL4 DNA-binding domain transfected in HEK293T cells showed a reporter luciferase activity. We screened food-derived and natural compounds using a reporter assay system to measure the transcriptional activity of PGC-1β. We found that soy-derived isoflavones, genistein and daidzein, and several resveratrols activated PGC-1β, see "Genistein, daidzein, and resveratrols stimulate PGC-1β-mediated gene expression" [1]. The list of 166 compounds and their reporter activity is shown here.

We examined the effect of long-term exercise on the prevention of sarcopenia using a senescence-accelerated-prone mice (SAMP8) model. Mice were housed in a wheel cage for 25 weeks to increase voluntary exercise. At week 23, endurance running capacity was examined using a treadmill. In a treadmill running test, the wheel cage group had increased endurance running capacity, which suggests that aging-related loss of muscle function was recovered by long-term exercise. Mice were sacrificed and microarray analysis revealed that genes involved in protein synthesis and degradation were upregulated in the skeletal muscles of the wheel cage group, suggesting accelerated protein turnover. Total body and adipose tissue weights decreased following the use of the wheel cage. Thus, long-term, spontaneous physical exercise may assist in recovering from aging-related sarcopenia (loss of muscle function) and obesity.

PGC-1β is a transcriptional co-activator of nuclear receptors such as the estrogen receptor-related receptor (ERR). Transgenic overexpression of PGC-1β in mice increases energy expenditure and suppresses high-fat diet-induced obesity. In this study, we screened various food-derived and natural compounds using a reporter assay system to measure the transcriptional activity of PGC-1β. Soy-derived isoflavones, genistein and daidzein, and several resveratrols activated PGC-1β. Genistein, daidzein, and trans-oxyresveratrol activated ERR-responsive element-mediated reporter activity in the presence of PGC-1β. Stable overexpression of PGC-1β in C2C12 myoblasts increased the expression of medium-chain acyl-CoA dehydrogenase ( MCAD ), an important enzyme in fatty acid β-oxidation. Genistein and daidzein increased MCAD mRNA levels and mitochondrial content in PGC-1β-expressing C2C12 cells. These compounds activated ERR/PGC-1β complex-mediated gene expression, and our findings may be a practical foundation for developing functional foods targeting obesity.

DNA methylation is an epigenetic mechanism regulating gene expression. In this study, we observed that DNA methyltransferase 3a (Dnmt3a) expression is decreased after muscle atrophy. We made skeletal muscle-specific Dnmt3a-knockout (Dnmt3a-KO) mice. The regeneration capacity after muscle injury was markedly decreased in Dnmt3a-KO mice. Diminished mRNA and protein expression of Dnmt3a were observed in skeletal muscles as well as in satellite cells, which are important for muscle regeneration, in Dnmt3a-KO mice. Dnmt3a-KO satellite cell showed smaller in size (length/area), suggesting suppressed myotube differentiation. Microarray analysis of satellite cells showed that expression of growth differentiation factor 5 (Gdf5) mRNA was markedly increased in Dnmt3a-KO mice. The DNA methylation level of the Gdf5 promoter was markedly decreased in Dnmt3a-KO satellite cells. In addition, DNA methylation inhibitor azacytidine treatment increased Gdf5 expression in wild-type satellite cells, suggesting Gdf5 expression is regulated by DNA methylation. Also, we observed increased inhibitor of differentiation (a target of Gdf5) mRNA expression in Dnmt3a-KO satellite cells. Thus, Dnmt3a appears to regulate satellite cell differentiation via DNA methylation. This mechanism may play a role in the decreased regeneration capacity during atrophy such as in aged sarcopenia.-Hatazawa, Y., Ono, Y., Hirose, Y., Kanai, S., Fujii, N. L., Machida, S., Nishino, I., Shimizu, T., Okano, M., Kamei, Y., Ogawa, Y. Reduced Dnmt3a increases Gdf5 expression with suppressed satellite cell differentiation and impaired skeletal muscle regeneration.

Background: Hepatocellular carcinoma (HCC) can develop in patients who are negative for the hepatitis B surface antigen (HBsAg) in serum but positive for hepatitis B virus (HBV) DNA in the liver, referred to as occult HBV infection (OBI). Previous reports showed that HBV variants in OBI-related HCC are different from those in HBsAg-positive HCC. In the present study, HBV quasispecies based on the pre-S/S gene in OBI-related HCC patients were examined by high throughput sequencing and compared with those in HBsAg-positive HCC., Methods: Nineteen tissue samples (9 OBI-related and 10 HBsAg-positive non-cancerous tissues) were collected at the time of surgery at Kobe University Hospital. The quasispecies with more than 1% variation in the pre-S/S region were isolated and analysed by ultra-deep sequencing., Results: There were no significant differences in the major HBV populations, which exhibit more than 20% variation within the entire pre-S/S region, between OBI-related HCC and HBsAg-positive HCC. However, the prevalences of major populations with pre-S2 region mutations and of minor populations with polymerized human serum albumin-binding domain mutations were significantly higher in OBI-related HCC than in HBsAg-positive HCC. Moreover, the major variant populations associated with the B-cell epitope, located within the pre-S1 region, and the a determinant domain, located in the S region, were detected frequently in HBsAg-positive HCC. The minor populations of variants harbouring the W4R, L30S, Q118R/Stop, N123D and S124F/P mutations in the pre-S region and the L21F/S and L42F/S mutations in the S region were detected more frequently in OBI-related HCC than in HBsAg-positive HCC., Conclusions: Ultra-deep sequencing revealed that the B-cell epitope domain in the pre-S1 region and alpha determinant domain in the S region were variable in HBsAg-positive HCC, although the quasispecies associated with the pre-S2 region were highly prevalent in OBI-related HCC., Trial Registration: Ref: R000034382/UMIN000030113; Retrospectively registered 25 November 2017., Competing Interests: The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the Medical and Health Research Ethics Committee (MHREC), Kobe University Graduate School of Medicine (Trial registration: Ref: 1856 [Approved 22 March 2016]). All subjects gave their written informed consent before enrolment.Not applicable.The authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The skeletal muscle is the largest organ in the human body, depositing energy as protein/amino acids, which are degraded in catabolic conditions such as fasting. Alanine is synthesized and secreted from the skeletal muscle that is used as substrates of gluconeogenesis in the liver. During fasting, the expression of PGC-1α, a transcriptional coactivator of nuclear receptors, is increased in the liver and regulates gluconeogenesis. In the present study, we observed increased mRNA expression of PGC-1α and alanine aminotransferase 2 (ALT2) in the skeletal muscle during fasting. In C2C12 myoblast cells overexpressing PGC-1α, ALT2 expression was increased concomitant with an increased alanine level in the cells and medium. In addition, PGC-1α, along with nuclear receptor ERR, dose-dependently enhanced the ALT2 promoter activity in reporter assay using C2C12 cells. In the absence of glucose in the culture medium, mRNA levels of PGC-1α and ALT2 increased. Endogenous PGC-1α knockdown in C2C12 cells reduced ALT2 gene expression level, induced by the no-glucose medium. Taken together, in the skeletal muscle, PGC-1α activates ALT2 gene expression, and alanine production may play roles in adaptation to fasting.

Vitamin D is known to be effective for the prevention of muscle atrophy, such as age-related sarcopenia. However, vitamin D action in skeletal muscle tissue and muscle cells is largely unknown. We previously found that a transcription factor, FOXO1 gene expression, was induced in various muscle atrophy conditions causing muscle atrophy by upregulating atrophy-related genes, including atrogin 1 (ubiquitin ligase) and cathepsin L (lysosomal proteinase). In this study, we found that vitamin D inhibited FOXO1-mediated transcriptional activity in a reporter gene assay. Moreover, vitamin D suppressed the glucocorticoid-induced gene expression of atrogin 1 and cathepsin L in C2C12 myoblasts. Thus, vitamin D may prevent muscle atrophy via the FOXO1-mediated pathway in muscle cells.

The purpose of antiviral therapy in chronic hepatitis B (CHB) is generally to achieve a decrease and ultimately disappearance of HBs antigen (HBsAg). Interferon (IFN) therapy of CHB appears to be less effective in Asian countries than in European countries, and the advantage of IFN and nucleotide(s) analog (NA) combination therapy has yet to be fully investigated. The present study focused on the factors associated with a decrease in HBs antigen following IFN monotherapy or IFN + NA combination therapy. A total of 35 patients with CHB who received IFN-based therapy (mean ± standard deviation age 36.7±8.5 years; 27 males and 8 females) were enrolled in this study. Of the 35 patients, 21 patients received pegylated IFN monotherapy and 14 patients received IFN and adefovir (ADV) combination therapy. We examined the factors associated with reductions in the HBsAg titer of >1.0 log IU/ml from the initial HBsAg titer to the end of treatment and to 24 weeks after treatment. Although 13 patients (37%) had a reduction in HBsAg of >1.0 IU/ml at the end of treatment, it was only maintained to 24 weeks after treatment in 7 patients (20%). The HBV core-related antigen (HBcrAg) titer before treatment was significantly higher in patients with a decrease in HBsAg at the end of treatment than in patients without a decrease in HBsAg (6.56±0.78 vs. 5.30±1.66 log IU/ml, P<0.05). Moreover, an increase in alanine aminotransferase (ALT) of >2 times from baseline occurred significantly more frequently in patients with a decrease in HBsAg (62 vs. 14%, P<0.05). The proportion of patients with a decrease in HBsAg was significantly greater in patients who received IFN monotherapy than in patients who received IFN and ADV combination therapy (43 vs. 29%, P<0.05). The present results revealed that the HBcr antigen titer before therapy and an on-treatment elevation of ALT (indicative of host instruction flare) are important factors associated with a decrease in HBsAg titers after IFN-based therapy. The efficacy of IFN and ADV combination therapy was not apparent in terms of a reduction in the HBsAg titer.

Branched-chain amino acids (BCAAs) are essential amino acids for mammals and play key roles in the regulation of protein metabolism. However, the effect of BCAA deficiency on protein metabolism in skeletal muscle in vivo remains unclear. Here we generated mice with lower BCAA concentrations by specifically accelerating BCAA catabolism in skeletal muscle and heart (BDK-mKO mice). The mice appeared to be healthy without any obvious defects when fed a protein-rich diet; however, bolus ingestion of BCAAs showed that mTORC1 sensitivity in skeletal muscle was enhanced in BDK-mKO mice compared to the corresponding control mice. When these mice were fed a low protein diet, the concentration of myofibrillar protein was significantly decreased (but not soluble protein) and mTORC1 activity was reduced without significant change in autophagy. BCAA supplementation in drinking water attenuated the decreases in myofibrillar protein levels and mTORC1 activity. These results suggest that BCAAs are essential for maintaining myofibrillar proteins during protein undernutrition by keeping mTORC1 activity rather than by inhibiting autophagy and translation. This is the first report to reveal the importance of BCAAs for protein metabolism of skeletal muscle in vivo.

The expression of the transcriptional coactivator PGC1α is increased in skeletal muscles during exercise. Previously, we showed that increased PGC1α leads to prolonged exercise performance (the duration for which running can be continued) and, at the same time, increases the expression of branched-chain amino acid (BCAA) metabolism-related enzymes and genes that are involved in supplying substrates for the TCA cycle. We recently created mice with PGC1α knockout specifically in the skeletal muscles (PGC1α KO mice), which show decreased mitochondrial content. In this study, global gene expression (microarray) analysis was performed in the skeletal muscles of PGC1α KO mice compared with that of wild-type control mice. As a result, decreased expression of genes involved in the TCA cycle, oxidative phosphorylation, and BCAA metabolism were observed. Compared with previously obtained microarray data on PGC1α-overexpressing transgenic mice, each gene showed the completely opposite direction of expression change. Bioinformatic analysis of the promoter region of genes with decreased expression in PGC1α KO mice predicted the involvement of several transcription factors, including a nuclear receptor, ERR, in their regulation. As PGC1α KO microarray data in this study show opposing findings to the PGC1α transgenic data, a loss-of-function experiment, as well as a gain-of-function experiment, revealed PGC1α's function in the oxidative energy metabolism of skeletal muscles., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Unloading stress, such as bed rest, inhibits the regenerative potential of skeletal muscles; however, the underlying mechanisms remain largely unknown. FOXO1 expression, which induces the upregulated expression of the cell cycle inhibitors p57 and Gadd45α, is known to be increased in the skeletal muscle under unloading conditions. However, there is no report addressing FOXO1-induced inhibition of myoblast proliferation. Therefore, we induced muscle injury by cardiotoxin in transgenic mice overexpressing FOXO1 in the skeletal muscle (FOXO1-Tg mice) and observed regeneration delay in skeletal muscle mass and cross-sectional area in FOXO1-Tg mice. Increased p57 and Gadd45α mRNA levels, and decreased proliferation capacity were observed in C2C12 myoblasts expressing a tamoxifen-inducible active form of FOXO1. These results suggest that decreased proliferation capacity of myoblasts by FOXO1 disrupts skeletal muscle regeneration under FOXO1-increased conditions, such as unloading.

Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) is a coactivator of various nuclear receptors and other transcription factors whose expression increases in the skeletal muscle during exercise. We have previously made transgenic mice overexpressing PGC-1α in the skeletal muscle (PGC-1α-Tg mice). PGC-1α upregulates the expression of genes associated with red fibers, mitochondrial function, fatty acid oxidation, and branched chain amino acid (BCAA) degradation. However, global analyses of the actual metabolic products have not been investigated. In this study, we conducted metabolomic analysis of the skeletal muscle in PGC-1α-Tg mice by capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry. Principal component analysis and hierarchical cluster analysis showed clearly distinguishable changes in the metabolites between PGC-1α-Tg and wild-type control mice. Changes were observed in metabolite levels of various metabolic pathways such as the TCA cycle, pentose phosphate pathway, nucleotide synthesis, purine nucleotide cycle, and amino acid metabolism, including BCAA and β-alanine. Namely, metabolic products of the TCA cycle increased in PGC-1α-Tg mice, with increased levels of citrate (2.3-fold), succinate (2.2-fold), fumarate (2.8-fold), and malate (2.3-fold) observed. Metabolic products associated with the pentose phosphate pathway and nucleotide biosynthesis also increased in PGC-1α-Tg mice. Meanwhile, BCAA levels decreased (Val, 0.7-fold; Leu, 0.8-fold; and Ile, 0.7-fold), and Glu (3.1-fold) and Asp (2.2-fold) levels increased. Levels of β-alanine and related metabolites were markedly decreased in PGC-1α-Tg mice. Coordinated regulation of the TCA cycle and amino acid metabolism, including BCAA, suggests that PGC-1α plays important roles in energy metabolism. Moreover, our metabolomics data showing the activation of the purine nucleotide pathway, malate-aspartate shuttle, as well as creatine metabolism, which are known to be active during exercise, further suggests that PGC-1α regulates metabolism in exercise. Thus, we demonstrated the roles of PGC-1α in the skeletal muscle at the metabolite level.

Skeletal muscle is a reservoir of energy in the form of protein, which is degraded under catabolic conditions, resulting in the formation of amino acids and ammonia as a byproduct. The expression of FOXO1, a forkhead-type transcription factor, increases during starvation and exercise. In agreement, transgenic FOXO1-Tg mice that overexpress FOXO1 in skeletal muscle exhibit muscle atrophy. The aim of this study was to examine the role of FOXO1 in amino acid metabolism. The mRNA and protein expressions of glutamine synthetase (GS) were increased in skeletal muscle of FOXO1-Tg mice. Fasting induced FOXO1 and GS expression in wild-type mice but hardly increased GS expression in muscle-specific FOXO1 knockout (FOXO1-KO) mice. Activation of FOXO1 also increased GS mRNA and protein expression in C2C12 myoblasts. Using a transient transfection reporter assay, we observed that FOXO1 activated the GS reporter construct. Mutation of a putative FOXO1-binding consensus sequence in the downstream genomic region of GS decreased basal and FOXO1-dependent reporter activity significantly. A chromatin immunoprecipitation assay showed that FOXO1 was recruited to the 3' region of GS in C2C12 myoblasts. These results suggest that FOXO1 directly upregulates GS expression. GS is considered to mediate ammonia clearance in skeletal muscle. In agreement, an intravenous ammonia challenge increased blood ammonia concentrations to a twofold higher level in FOXO1-KO than in wild-type mice, demonstrating that the capacity for ammonia disposal correlated inversely with the expression of GS in muscle. These data indicate that FOXO1 plays a role in amino acid metabolism during protein degradation in skeletal muscle., (Copyright © 2014 the American Physiological Society.)

Telaprevir, a non-structural (NS)3/4A protease inhibitor, is a direct-acting antiviral drug that inhibits viral replication. Triple therapy with telaprevir, pegylated interferon, and ribavirin is a standard therapeutic regimen for patients with genotype 1b chronic hepatitis C virus (HCV) infection and a high viral load. Several factors, including mutations in the NS5A gene, are important predictors of the efficacy of interferon therapy. In this study, we examined the mutational diversity of NS5A and its impact on the efficacy of triple therapy. We enrolled patients with genotype 1b chronic HCV infection and a high viral load (31 males/17 females; mean age, 57.6 years), who were treated with triple therapy. This study was conducted at Kobe University Hospital and at three affiliated hospitals in Hyogo prefecture, Japan, between November 2011 and June 2013. A sustained viral response after 12 weeks (SVR12) was achieved in 37/48 patients (77%). Based on intent-to-treat analysis, SVR12 was significantly greater in patients with the major allele than in those with the minor allele for the IL28B single nucleotide polymorphism (SNP; 88 vs. 56%; P<0.05). The prevalence of the V2334I mutation in NS5A was significantly higher in patients who achieved SVR12, while that of G2356E was significantly higher in patients who did not achieve SVR12 (P<0.05). Mutations in the NS3 region that are thought to confer resistance to telaprevir were detected in 3/27 patients who achieved SVR12 (Val36, n=3) and in 5/10 patients who did not achieve SVR12 (Val36, n=4; Thr54, n=1). In conclusion, the IL28B SNP and mutations in the NS5A region were associated with the therapeutic response to triple therapy. Half of the patients who did not achieve SVR12 had mutations conferring resistance to telaprevir. However, pre-existing mutations in NS3 did not affect the efficacy of triple therapy.

Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) is a coactivator of various nuclear receptors and other transcription factors, which is involved in the regulation of energy metabolism, thermogenesis, and other biological processes that control phenotypic characteristics of various organ systems including skeletal muscle. PGC-1α in skeletal muscle is considered to be involved in contractile protein function, mitochondrial function, metabolic regulation, intracellular signaling, and transcriptional responses. Branched-chain amino acid (BCAA) metabolism mainly occurs in skeletal muscle mitochondria, and enzymes related to BCAA metabolism are increased by exercise. Using murine skeletal muscle overexpressing PGC-1α and cultured cells, we investigated whether PGC-1α stimulates BCAA metabolism by increasing the expression of enzymes involved in BCAA metabolism. Transgenic mice overexpressing PGC-1α specifically in the skeletal muscle had increased the expression of branched-chain aminotransferase (BCAT) 2, branched-chain α-keto acid dehydrogenase (BCKDH), which catabolize BCAA. The expression of BCKDH kinase (BCKDK), which phosphorylates BCKDH and suppresses its enzymatic activity, was unchanged. The amount of BCAA in the skeletal muscle was significantly decreased in the transgenic mice compared with that in the wild-type mice. The amount of glutamic acid, a metabolite of BCAA catabolism, was increased in the transgenic mice, suggesting the activation of muscle BCAA metabolism by PGC-1α. In C2C12 cells, the overexpression of PGC-1α significantly increased the expression of BCAT2 and BCKDH but not BCKDK. Thus, PGC-1α in the skeletal muscle is considered to significantly contribute to BCAA metabolism.

A 63-year-old male patient underwent artificial pneumothorax for right pulmonary tuberculosis 39 years ago, and thereafter suffered from chronic empyema, though asymptomatic. In December, 1989, he was found to have a 5 cm tumor in his right chest wall. The tumor grew to 15 cm in 2 weeks and was associated with severe pain. A chest CT revealed that the tumor of the chest wall corresponded to the area of the wall affected by empyema. The patient underwent full thickness resection of the chest wall including the tumor and the empyematous wall (20 x 20 cm) on March 7, 1990. The tumor was 11 x 8 x 7 cm large and had developed from the empyematous wall to the lateral side of chest wall. There was no invasion of the thoracic cavity by the empyema. The lesion was pathologically diagnosed as diffuse, large to intermediate T-cell non-Hodgkin's lymphoma. Postoperatively the patient was treated with radiotherapy and VEPA therapy, but the tumor metastasized to both lungs, and the patient died 161 days after surgery. The majority of cases of malignant lymphoma reported to have originated in empyematous chest walls have been of the B-cell type. The T-cell type is rare, and the present case is only the second case reported. Chest CT was an effective method of diagnostic imaging in this disease.