ABSTRACT
BACKGROUND: Trastuzumab has improved breast cancer (BC) prognosis and reduced anthracycline use. However, the characteristic changes of anthracycline-related cardiomyopathy (ARCM) in patients with BC remain unclear. We aimed to update our understanding of ARCM in the trastuzumab era. METHODS: This retrospective observational cohort study included 2959 patients with BC treated with anthracyclines at three regional cancer centers in Niigata City between 1990 and 2020. Seventy-five patients (2.5%) developed ARCM and were categorized into two groups: pre- 2007 (early phase) and post-2007 (late phase), corresponding to before and during the trastuzumab era in Japan. RESULTS: ARCM incidence peaked at 6% in the 1990s, then decreased and stabilized at 2% until the 2010s. Survivors of anthracycline-treated BC increased more rapidly in the late phase, with four times as many patients with ARCM compared to the end of the early phase (26 and six, respectively). Although the rate of change in accumulation from the early phase to the late phase was slight in the anthracycline-treated BC group, it was more pronounced in the ARCM group (P < 0.001). Mean anthracycline use in the late phase was significantly lower than in the early phase (307 vs. 525 mg/m2, P < 0.001). Five-year survival rates in the late phase tended to be higher than early phase (45% and 28%, respectively. P = 0.058). Human epidermal growth factor receptor type 2 (HER2) positivity with trastuzumab therapy in the late phase was an independent predictor for mortality within 10 years (hazard ratio = 0.24, 95% confidence interval: 0.10-0.56; P = 0.001). CONCLUSIONS: HER2-positive patients with ARCM receiving trastuzumab therapy had a better prognosis than HER2-positive and HER2-negative patients with ARCM not receiving trastuzumab therapy, and this trend has been increasing in the trastuzumab era. These findings highlight the importance of HER2-targeted treatments in improving prognosis for BC patients with ARCM.
ABSTRACT
In recent years, there has been significant interest in quantum technology, characterized by the emergence of quantum computers boasting immense processing power, ultra-sensitive quantum sensors, and ultra-precise atomic clocks. Miniaturization of quantum devices using cold atoms necessitates the employment of an ultra-high vacuum miniature cell with a pressure of approximately 10-6 Pa or even lower. In this study, we developed an ultra-high vacuum cell realized by a miniature ion pump using a high-efficiency plasma source. Initially, an unsealed miniature ion pump was introduced into a vacuum chamber, after which the ion pump's discharge current, depending on vacuum pressures, was evaluated. Subsequently, a miniature vacuum cell was fabricated by hermetically sealing the miniature vacuum pump. The cell was successfully evacuated by a miniature ion pump down to an ultra-high vacuum region, which was derived by the measured discharge current. Our findings demonstrate the feasibility of achieving an ultra-high vacuum cell necessary for the operation of miniature quantum devices.
ABSTRACT
A 45-year-old woman with no medical history underwent pacemaker implantation for a symptomatic complete atrioventricular block. On day 6, she noticed diplopia and then fever, general malaise, and elevation of serum creatinine kinase (CK). She was transferred to our hospital on day 21. Serum CK was elevated to 4543â¯IU/L, and echocardiography revealed a left ventricular ejection fraction of 43â¯%. We diagnosed her with giant cell myocarditis (GCM) via an emergent myocardial biopsy that revealed a proliferation of lymphocytes, eosinophils, and giant cells without granulomas. Initial treatment with high doses of intravenous methylprednisolone and immunoglobulin improved her symptoms in a few days, and prednisolone was given as follow-up treatment. CK was normalized in a week and a thinning of the interventricular septum mimicking cardiac sarcoidosis (CS) occurred. On day 38, we added a calcineurin inhibitor, tacrolimus, and maintained her with a combination of prednisolone and tacrolimus at a target dose of 10-15â¯ng/mL. Six months after the onset, there were no signs of relapse despite the persistent mild elevation of troponin I levels. We present a case of GCM mimicking CS successfully maintained by a combination of two immunosuppressive agents. Learning objective: Recommended treatment for giant cell myocarditis (GCM), a potentially fatal disease, is a combination of three immunosuppressive agents. However, GCM shares many characteristics with cardiac sarcoidosis (CS), which is treated using prednisolone alone in many cases. Recent studies on GCM and CS suggest they are different spectrums of a common entity. Although they can clinically overlap, they have different progressive speeds and severities. We present a case of GCM mimicking CS successfully treated with a combination of two immunosuppressive agents.
ABSTRACT
Immunosuppressive therapy with prednisolone (PSL) is the first-line treatment for cardiac sarcoidosis (CS), and 18F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is used to evaluate its efficacy to guide treatment. However, the appropriate timing of FDG-PET in CS remains unknown. This single-center, retrospective, observational study included 15 consecutive CS patients who underwent 3 serial FDG-PET scans (at baseline, in the early phase [1-2 months after PSL introduction], and in the late phase [≥ 5 months after PSL introduction with a maintenance dose of PSL]). We adhered to the PSL tapering protocol by the Japanese Circulation Society even when early FDG-PET showed positive results (SUVmax ≥ 4.0). No patient died during the 908 (644-1600) days of observation. Negative results in the late phase were observed in 3 of 6 early-positive patients, and 3 of 9 early-negative patients showed positive results in the late phase. Changes in echocardiographic parameters from baseline to the late phase were significantly better in late-negative patients than in late-positive patients (left ventricular end-diastolic diameter: -0.7 (-9.3-[-0.5]) mm versus +3.5 (0.8-7.5) mm, P = 0.039; left ventricular end-systolic diameter: -4.2 (-6.9-[-0.1]) mm versus +5.1 (0.5-7.0) mm, P = 0.015; left ventricular ejection fraction: +4.7% (-1.0-9.0%) versus -1.5% (-11.3-1.5%), P = 0.045) ), although early FDG-PET did not predict those consequent changes. An interval of ≥ 5 months after introducing the PSL with a maintenance dose of PSL is long enough for FDG-PET to reflect consequent left ventricular functions, while an interval of 1-2 months can be too short.
Subject(s)
Cardiomyopathies , Myocarditis , Sarcoidosis , Humans , Prednisolone/therapeutic use , Fluorodeoxyglucose F18 , Cardiomyopathies/diagnostic imaging , Cardiomyopathies/drug therapy , Radiopharmaceuticals , Positron-Emission Tomography/methods , Sarcoidosis/diagnostic imaging , Sarcoidosis/drug therapy , Retrospective StudiesABSTRACT
OBJECTIVE: Improving mitochondrial function is a promising strategy for intervention in type 2 diabetes mellitus. This study investigated the preventive effects of sodium ferrous citrate (SFC) and 5-aminolevulinic acid phosphate (ALA) on several metabolic dysfunctions associated with obesity because they have been shown to alleviate abnormal glucose metabolism in humans. METHODS: Six-week-old male C57BL/6J mice were fed with a normal diet, a high-fat diet, or a high-fat diet supplemented with SFC and ALA for 15 weeks. RESULTS: The simultaneous supplementation of SFC + ALA to high-fat diet-fed mice prevented loss of muscle mass, improved muscle strength, and reduced obesity and insulin resistance. SFC + ALA prevented abnormalities in mitochondrial morphology and reverted the diet effect on the skeletal muscle transcriptome, including the expression of glucose uptake and mitochondrial oxidative phosphorylation-related genes. In addition, SFC + ALA prevented the decline in mitochondrial DNA copy number by enhancing mitochondrial DNA maintenance and antioxidant transcription activity, both of which are impaired in high-fat diet-fed mice during long-term fasting. CONCLUSIONS: These findings suggest that SFC + ALA supplementation exerts its preventive effects in type 2 diabetes mellitus via improved skeletal muscle and mitochondrial health, further validating its application as a promising strategy for the prevention of obesity-induced metabolic disorders.
Subject(s)
Aminolevulinic Acid , Citric Acid , Ferrous Compounds , Mitochondria , Muscle, Skeletal , Animals , Mice , Ferrous Compounds/pharmacology , Citric Acid/pharmacology , Aminolevulinic Acid/pharmacology , Diabetes Mellitus, Type 2 , Mice, Inbred C57BL , Mitochondria/metabolism , Muscle, Skeletal/metabolism , Insulin Resistance , Diet, High-Fat , DNA, MitochondrialABSTRACT
This study aimed to evaluate the effects of an ultraviolet (UV) curable coating material on denture base resin. The results of the three-point bending test showed no significant difference between treated and untreated specimens, suggesting that the UV curable coating material did not compromise the physical strength of denture base resin. The surface free energy measurement and the surface analysis with atomic force microscopy revealed superhydrophilicity and a regularly arranged structure on the coating surface, improving wettability. Moreover, untreated specimens were significantly discolored in the staining test. However, specimens treated with the UV curable coating material showed no significant difference in color with slight staining, suggesting excellent antifouling ability. Therefore, the UV curable coating material used in this study could contribute to simplifying hygiene without altering the physical properties of denture base resins.
Subject(s)
Coloring Agents , Denture Bases , Surface Properties , Wettability , Materials Testing , Polymethyl Methacrylate/chemistryABSTRACT
In this study, we design a highly efficient plasma source using a magnetic mirror trap with two opposing permanent magnets for a miniature high-efficiency ion pump. First, we simulated the distribution of the magnetic field line formed by the proposed magnetic mirror configuration. By optimizing the distance between two opposing permanent magnets and size of these magnets, a magnetic mirror ratio value of 27 could be obtained, which is an electron confinement efficiency of over 90%. We also conducted an experiment on a high-efficiency discharge plasma source for a miniature ion pump using an optimized magnetic circuit. As a result, we revealed that the proposed magnetic circuit has a pronounced effect on plasma generation, particularly in the high-vacuum region.
Subject(s)
Magnetics , Magnets , Magnetic Fields , Vacuum , ElectronsABSTRACT
Objective Spontaneous mechanical alternans (MA), or pulsus alternans, has been observed in heart failure patients with hypertension or tachycardia for 150 years and is considered a sign of a poor prognosis. However, in some dilated cardiomyopathy (DCM) patients with MA, optimal medical therapy (OMT) brings left ventricular reverse remodeling (LVRR), a preferable prognostic indicator. This study examined the probability of LVRR in DCM patients with spontaneous MA and whether or not LVRR can be predicted by the baseline blood pressure or heart rate. Methods We conducted a single-center, retrospective observational study of newly diagnosed DCM patients from January 2017 to December 2020. Results Thirty-three newly diagnosed DCM patients were retrospectively examined. Spontaneous MA was observed during diagnostic cardiac catheterization in at least 1 of the pressure waveforms of the aorta, left ventricle, pulmonary artery, or right ventricle in 10 patients (30%) (MA-group). LVRR after OMT was achieved roughly equally in the MA group (6 of 10, 60%) and the non-MA group (12 of 23, 52%). In the MA group, those who achieved LVRR had a significantly higher baseline systolic aortic pressure (more than 120 mmHg in all 6 patients) than those who did not, although the baseline heart rate did not show a significant correlation with LVRR. In contrast, in the non-MA group, LVRR was unrelated to the baseline aortic pressure or heart rate. Conclusion The probability of LVRR in newly-diagnosed DCM patients with spontaneous MA was similar to that in those without spontaneous MA. Spontaneous MA may not necessarily be a sign of a poor prognosis if observed in patients with a preserved blood pressure.
Subject(s)
Cardiomyopathy, Dilated , Heart Failure , Humans , Cardiomyopathy, Dilated/complications , Ventricular Function, Left/physiology , Retrospective Studies , Blood Pressure , PrognosisABSTRACT
Food crises caused by growing global population or environmental changes are predicted in the near future; therefore, sustainable solutions are needed. Edible insects, which are rich in protein and can save feed and environmental resources, have the potential to be a sustainable alternative protein source. However, there is limited evidence on the impact on health. In this study, we investigated the biological effects of ingesting bee larva by examining their effects on amino acid, lipid, and glucose metabolism in animal models. In our animal experiments, the replacement of casein as a protein source, with edible insects, did not seem to cause any deficiency in murine amino acid levels in the plasma and liver. Metabolomic analysis of plasma metabolites showed decreased 3-methylhistidine and increased nicotinamide in the bee larva-derived protein-fed mice. Decreased levels of plasma 3-metylhistidine, an indicator of muscle degradation, implies that replacement to bee-larva protein from casein did not cause muscle degradation in vivo. We further investigated effects of increased plasma nicotinamide on peripheral tissue and found an increase in expression levels of genes involved in glucose uptake in muscle and thermogenesis in adipose tissue. These data imply that bee larva is a potential sustainable, safe and healthy alternative protein source.
ABSTRACT
Disruption of iron metabolism is closely related to metabolic diseases. Iron deficiency is frequently associated with obesity and hepatic steatosis. However, the effects of iron supplementation on obesity and energy metabolism remain unclear. Here we show that a high-fat diet supplemented with iron reduces body weight gain and hepatic lipid accumulation in mice. Iron supplementation was found to reduce mitochondrial morphological abnormalities and upregulate gene transcription involved in mitochondrial function and beta oxidation in the liver and skeletal muscle. In both these tissues, iron supplementation increased the expression of genes involved in heme or iron-sulfur (Fe-S) cluster synthesis. Heme and Fe-S cluster, which are iron prosthetic groups contained in electron transport chain complex subunits, are essential for mitochondrial respiration. The findings of this study demonstrated that iron regulates mitochondrial signaling pathways-gene transcription of mitochondrial component molecules synthesis and their energy metabolism. Overall, the study elucidates the molecular basis underlying the relationship between iron supplementation and obesity and hepatic steatosis progression, and the role of iron as a signaling molecule.
Subject(s)
Diet, High-Fat/adverse effects , Fatty Liver/drug therapy , Gene Expression Profiling/methods , Iron/administration & dosage , Mitochondrial Proteins/genetics , Obesity/drug therapy , Animals , Cells, Cultured , Disease Progression , Energy Metabolism/drug effects , Fatty Liver/chemically induced , Gene Expression Regulation/drug effects , Hepatocytes/cytology , Iron/pharmacology , Lipid Metabolism/drug effects , Male , Mice , Obesity/chemically induced , Sequence Analysis, DNA , Signal Transduction/drug effects , Treatment OutcomeABSTRACT
The incidence of dry eye disease is increasing worldwide because of the aging population and increasing use of information technology. Dry eye disease manifests as tear-layer instability and inflammation caused by osmotic hypersensitization in tear fluids; however, to our knowledge, no agent that treats both pathologies simultaneously is available. Molecular hydrogen (H2) is known to be effective against various diseases; therefore, we aimed to elucidate the effects of H2 on tear dynamics and the treatment of dry eye disease. We revealed that administering a persistent H2-generating supplement increased the human exhaled H2 concentration (p < 0.01) and improved tear stability (p < 0.01) and dry eye symptoms (p < 0.05) significantly. Furthermore, H2 significantly increased tear secretion in healthy mice (p < 0.05) and significantly suppressed tear reduction in a murine dry eye model (p = 0.007). H2 significantly and safely improved tear stability and dry eye symptoms in a small exploratory group of 10 human subjects, a subset of whom reported dry eye symptoms prior to treatment. Furthermore, it increased tear secretion rapidly in normal mice. Therefore, H2 may be a safe and effective new treatment for dry eye disease and thus larger trials are warranted.
Subject(s)
Dry Eye Syndromes/prevention & control , Hydrogen/therapeutic use , Lacrimal Apparatus/drug effects , Adult , Animals , Dry Eye Syndromes/drug therapy , Female , Humans , Hydrogen/administration & dosage , Lacrimal Apparatus/physiology , Male , Mice , Mice, Inbred C57BL , Tears/physiologyABSTRACT
Asperuloside (ASP) is an iridoid glycoside that is extracted from Eucommia leaves. Eucommia is used in traditional Chinese medicine and has a long history of benefits on health and longevity. Here, we investigated the impact of ASP on obesity-related metabolic disorders and show that ASP reduces body weight gain, glucose intolerance, and insulin resistance effectively in mice fed with a high-fat diet (HFD). Intestinal dysbiosis is closely linked with metabolic disorders. Our data indicate that ASP achieves these benefits on metabolic homeostasis by reversing HFD-induced gut dysbiosis and by changing gut-derived secondary metabolites and metabolic signaling. Our results indicate that ASP may be used to regulate gut microbiota for the treatment of obesity and type 2 diabetes.
ABSTRACT
While brown adipose tissue (BAT) is well-recognized for its ability to dissipate energy in the form of heat, recent studies suggest multifaced roles of BAT in the regulation of glucose and lipid homeostasis beyond stimulating thermogenesis. One of the functions involves interorgan communication with metabolic organs, such as the liver, through BAT-derived secretory factors, a.k.a., batokine. However, the identity and the roles of such mediators remain insufficiently understood. Here, we employed proteomics and transcriptomics in human thermogenic adipocytes and identified previously unappreciated batokines, including phospholipid transfer protein (PLTP). We found that increased circulating levels of PLTP, via systemic or BAT-specific overexpression, significantly improve glucose tolerance and insulin sensitivity, increased energy expenditure, and decrease the circulating levels of cholesterol, phospholipids, and sphingolipids. Such changes were accompanied by increased bile acids in the circulation, which in turn enhances glucose uptake and thermogenesis in BAT. Our data suggest that PLTP is a batokine that contributes to the regulation of systemic glucose and lipid homeostasis as a mediator of BAT-liver interorgan communication.
Subject(s)
Adipose Tissue, Brown , Glucose , Adipose Tissue, Brown/metabolism , Energy Metabolism , Glucose/metabolism , Homeostasis , Humans , Lipids , Liver , ThermogenesisABSTRACT
Salt is an essential nutrient; however, excessive salt intake is a prominent public health concern worldwide. Various physiological functions are associated with circadian rhythms, and disruption of circadian rhythms is a prominent risk factor for cardiovascular diseases, cancer, and immune disease. Certain nutrients are vital regulators of peripheral circadian clocks. However, the role of a high-fat and high-salt (HFS) diet in the regulation of circadian gene expression is unclear. This study aimed to investigate the effect of an HFS diet on rhythms of locomotor activity, caecum glucocorticoid secretion, and clock gene expression in mice. Mice administered an HFS diet displayed reduced locomotor activity under normal light/dark and constant dark conditions in comparison with those administered a normal diet. The diurnal rhythm of caecum glucocorticoid secretion and the expression levels of glucocorticoid-related genes and clock genes in the adrenal gland were disrupted with an HFS diet. These results suggest that an HFS diet alters locomotor activity, disrupts circadian rhythms of glucocorticoid secretion, and downregulates peripheral adrenal gland circadian clock genes.
Subject(s)
Circadian Rhythm/physiology , Diet, High-Fat , Glucocorticoids/biosynthesis , Motor Activity/physiology , Sodium Chloride, Dietary , Adrenal Glands/metabolism , Animals , Circadian Clocks/physiology , Male , Mice , Period Circadian Proteins/genetics , Period Circadian Proteins/metabolismABSTRACT
Non-alcoholic steatohepatitis (NASH) is a progressive disease that occurs in the liver. As the number of people with NASH has increased, effective prevention and treatment strategies are needed. Agaricus brasiliensis KA21 (AGA) is a mushroom native to Brazil and is considered a healthy food because of its purported health benefits, including its antioxidant properties. In this study, we focused on the oxidative stress that accompanies the onset of NASH and examined whether AGA can prevent NASH development through its antioxidant activity. We used a mouse model of NASH in which pathogenesis was promoted by dietary induction. Supplementation with AGA attenuated the development of hepatic fibrosis, which is a characteristic feature of late-stage NASH. This effect appeared to be mechanistically linked to an AGA-promoted reduction in hepatic oxidative stress. These results demonstrate a novel role for AGA in NASH prevention.
ABSTRACT
A high-calorie diet causes fat accumulation and oxidative stress in the liver, leading to fatty liver and eventually non-alcoholic steatohepatitis (NASH). Melon GliSODin® is used as a nutritional supplement because of its antioxidant activity. This study aimed to assess the antioxidant activity of Melon GliSODin® and its effectiveness in preventing NASH, which primarily results from oxidative stress. Furthermore, we verified the protective effect of Melon GliSODin® by administering it to a mouse model of diet-induced NASH. Melon GliSODin® suppressed liver fibrosis and fat accumulation, which is characteristic of the NASH phenotype. Gene expression analysis confirmed the suppression of fat synthesis and activation of antioxidative mechanisms. These results show that Melon GliSODin® mitigates NASH onset at the molecular level, suggesting its potential application as a NASH preventive agent.
Subject(s)
Antioxidants/pharmacology , Cucurbitaceae/chemistry , Lipogenesis/drug effects , Liver Cirrhosis, Experimental/prevention & control , Liver/drug effects , Non-alcoholic Fatty Liver Disease/prevention & control , Oxidative Stress/drug effects , Plant Extracts/pharmacology , Animals , Antioxidants/isolation & purification , Diet, High-Fat , Down-Regulation , Gene Expression Regulation , Lipogenesis/genetics , Liver/metabolism , Liver/pathology , Liver Cirrhosis, Experimental/genetics , Liver Cirrhosis, Experimental/metabolism , Liver Cirrhosis, Experimental/pathology , Male , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Plant Extracts/isolation & purificationABSTRACT
BACKGROUND & AIMS: Most cholesterol gallstones have a core consisting of inorganic and/or organic calcium salts, although the mechanisms of core formation are poorly understood. We examined whether the paracellular permeability of ions at hepatic tight junctions is involved in the core formation of cholesterol gallstones, with particular interest in the role of phosphate ion, a common food additive and preservative. METHODS: We focused on claudin-3 (Cldn3), a paracellular barrier-forming tight junction protein whose expression in mouse liver decreases with age. Since Cldn3-knockout mice exhibited gallstone diseases, we used them to assess the causal relationship between paracellular phosphate ion permeability and the core formation of cholesterol gallstones. RESULTS: In the liver of Cldn3-knockout mice, the paracellular phosphate ion permeability through hepatic tight junctions was significantly increased, resulting in calcium phosphate core formation. Cholesterol overdose caused cholesterol gallstone disease in these mice. CONCLUSION: We revealed that in the hepatobiliary system, Cldn3 functions as a paracellular barrier for phosphate ions, to help maintain biliary ion homeostasis. We provide in vivo evidence that elevated phosphate ion concentrations play a major role in the lifestyle- and age-related risks of developing cholesterol gallstone disease under cholesterol overdose. LAY SUMMARY: Herein, we reveal a new mechanism for cholesterol gallstone formation, in which increased paracellular phosphate ion permeability across hepatobiliary epithelia causes calcium phosphate core formation and cholesterol gallstones. Thus, altered phosphate ion metabolism under cholesterol overdose plays a major role in the lifestyle- and age-related risks of developing cholesterol gallstone disease.
Subject(s)
Bile Canaliculi/metabolism , Cell Membrane Permeability/physiology , Cholesterol/metabolism , Claudin-3/metabolism , Gallstones/metabolism , Aging/physiology , Animals , Aquaporins/metabolism , Calcium/metabolism , Calcium Phosphates/metabolism , Claudin-3/genetics , Claudins/genetics , Claudins/metabolism , Female , Gene Knockout Techniques , Liver/metabolism , Male , Mice , Mice, Knockout , Phosphorus/metabolism , Tight Junctions/metabolismABSTRACT
Our study aimed at finding a mechanistic relationship between the gut microbiome and breast cancer. Breast cancer cells are not in direct contact with these microbes, but disease could be influenced by bacterial metabolites including secondary bile acids that are exclusively synthesized by the microbiome and known to enter the human circulation. In murine and bench experiments, a secondary bile acid, lithocholic acid (LCA) in concentrations corresponding to its tissue reference concentrations (< 1 µM), reduced cancer cell proliferation (by 10-20%) and VEGF production (by 37%), aggressiveness and metastatic potential of primary tumors through inducing mesenchymal-to-epithelial transition, increased antitumor immune response, OXPHOS and the TCA cycle. Part of these effects was due to activation of TGR5 by LCA. Early stage breast cancer patients, versus control women, had reduced serum LCA levels, reduced chenodeoxycholic acid to LCA ratio, and reduced abundance of the baiH (7α/ß-hydroxysteroid dehydroxylase, the key enzyme in LCA generation) gene in fecal DNA, all suggesting reduced microbial generation of LCA in early breast cancer.
Subject(s)
Apoptosis/drug effects , Bacteria/metabolism , Breast Neoplasms/drug therapy , Cell Movement/drug effects , Cell Proliferation/drug effects , Detergents/pharmacology , Lithocholic Acid/pharmacology , Animals , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Humans , Mice , Mice, Inbred BALB C , Middle Aged , Prognosis , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Gut microbiota plays a significant role in the development of hepatocellular carcinoma (HCC) in non-alcoholic steatohepatitis (NASH). However, understanding of the precise mechanism of this process remains incomplete. A new class steatohepatitis-inducing high-fat diet (HFD), namely STHD-01, can promote the development of HCC without the administration of chemical carcinogens. Using this diet, we comprehensively analyzed changes in the gut microbiota and its metabolic functions during the development of HCC in NASH. Mice fed the STHD-01 developed NASH within 9 weeks. NASH further progressed into HCC by 41 weeks. Treatment with antibiotics significantly attenuated liver pathology and suppressed tumor development, indicating the critical role of the gut microbiota in tumor development in this model. Accumulation of cholesterol and bile acids in the liver and feces increased after feeding the mice with STHD-01. Treatment with antibiotics did not reverse these phenotypes. In contrast, accumulation of secondary bile acids was dramatically reduced after the treatment with antibiotics, suggesting the critical role of the gut microbiota in the conversion of primary bile acids to secondary bile acids. Secondary bile acids such as deoxycholic acid activated the mTOR, pathway in hepatocytes. Activation of mTOR was observed in the liver of mice fed STHD-01, and the activation was reduced when mice were treated with antibiotics. Collectively, bile acid metabolism by the gut microbiota promotes HCC development in STHD-01-induced NASH.