Publications by authors named "Mayuko Ichimura-Shimizu"

Endothelial dysfunction contributes to the progression of metabolic-dysfunction-associated steatotic liver disease (MASLD). Pemafibrate has been shown to ameliorate MASLD in basic and clinical studies, but it is unclear whether it is also effective in the status of endothelial dysfunction. An MASLD animal model was induced in male wild-type (WT) and endothelial nitric oxide synthase (eNOS)-deficient (eNOSKO) mice by feeding them a high-fat/cholesterol/cholate diet, and they were administered either a vehicle or pemafibrate at 0.

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A high-fat/cholesterol/cholate-based (iHFC) diet induces pathological changes in Tsumura-Suzuki non-obese (TSNO) mice, resembling human metabolic dysfunction associated steatohepatitis (MASH), along with advanced liver fibrosis. In this study, we investigated the role of cholic acid (CA) in the development of iHFC diet-induced MASH development. In mice receiving an iHFC diet without CA (CA(-) iHFC diet), both lobular inflammation and fibrosis progression in the liver were attenuated compared to those on the standard iHFC diet.

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The high rate of chronic hepatitis, including hepatitis B, C and D, in Mongolia creates a large health burden of advanced liver disease. This includes liver failure and the highest incidence rate of hepatocellular carcinoma (HCC) worldwide. In the present study, we histopathologically examined 69 recent cases of HCC from the Mongolian National Center for Pathology, which collects specimens from across the country.

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Over the past decade, numerous metabolomics techniques have been developed using liquid chromatography-mass spectrometry (LC-MS). These methodologies have yielded significant findings and facilitated the identification of biomarkers. Among these, chemical-tagging methodologies combined with isotope surrogate tags have garnered considerable attention as a leading approach.

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: Viral hepatitis, particularly hepatitis B (HBV) and hepatitis C (HCV), is highly prevalent in Mongolia. Moreover, Mongolia has the highest prevalence of hepatitis delta virus (HDV) globally, with over 60% of HBV-infected individuals also co-infected with HDV. Since HBV/HDV infections accelerate liver disease progression more compared to HBV infection alone, urgent national health measures are required.

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Indigo naturalis (IN), derived from the leaves of the indigo plant, is a traditional Chinese medicine that has historically been used for its anti-inflammatory properties in the treatment of various diseases, including ulcerative colitis (UC). However, long-term use of IN in UC patients is incontrovertibly associated with the onset of pulmonary arterial hypertension (PAH). To investigate the mechanisms by which IN induces PAH, we focused on the raw material of IN, indigo leaves (IL).

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Article Synopsis
  • Evidence indicates that bile acid (BA) plays a critical role in the progression of primary biliary cholangitis (PBC) by affecting immune responses and the gut microbiome.
  • A study using a unique mouse model (Cyp2c70/Cyp2a12 DKO) showed that a high-fat diet (HFD) significantly worsened cholangitis and led to cirrhosis compared to a normal diet, with changes in cytokines and BA levels.
  • The HFD altered gut microbiota composition, which correlated with changes in BA production and regulation, highlighting potential connections to the severity of PBC in humans.
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The potential involvement of the gut microbiota in metabolic dysfunction-associated steatohepatitis (MASH) pathogenesis has garnered increasing attention. In this study, we elucidated the link between high-fat/cholesterol/cholate-based (iHFC)#2 diet-induced MASH progression and gut microbiota in C57BL/6 mice using antibiotic treatments. Treatment with vancomycin (VCM), which targets gram-positive bacteria, exacerbated the progression of liver damage, steatosis, and fibrosis in iHFC#2-fed C57BL/6 mice.

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Brain-derived neurotrophic factor (BDNF) is a growth factor that promotes the survival and growth of developing neurons. It also enhances circuit formation to synaptic transmission for mature neurons in the brain. However, reduced BDNF expression and single nucleotide polymorphisms (SNP) are reported to be associated with functional deficit and disease development in the brain, suggesting that BDNF is a crucial molecule for brain health.

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Background: Tsumura-Suzuki non-obese (TSNO) mice exhibit a severe form of metabolic dysfunction-associated steatohepatitis (MASH) with advanced liver fibrosis upon feeding a high-fat/cholesterol/cholate-based (iHFC) diet. Another ddY strain, Tsumura-Suzuki diabetes obese (TSOD) mice, are impaired in the progression of iHFC diet-induced MASH.

Aim: To elucidate the underlying mechanisms contributing to the differences in MASH progression between TSNO and TSOD mice.

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Article Synopsis
  • - Liver fibrosis is traditionally evaluated using methods that only assess collagen content, but the study proposes a new technique called polarization-resolved second harmonic generation (PR-SHG) microscopy to analyze collagen fiber orientation and crystallization.
  • - Researchers studied liver samples from autopsy cases across fibrosis stages F0-F4, using PR-SHG to capture images by adjusting the laser polarization angle, revealing how collagen properties change with fibrosis progression.
  • - The study found that while the overall collagen content increased with fibrosis, the orientation of the fiber (φ) remained random; however, the mean crystallinity (ρ) significantly increased in stage F4, suggesting PR-SHG reveals crucial details about collagen fiber properties in liver fibrosis.
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Nonalcoholic steatohepatitis (NASH) can progress to hepatic fibrosis, and is associated with cardiovascular and liver-related mortality. To understand the pathogenesis of NASH, reliable animal models of the disease are useful. In animal studies, the animals are usually fasted overnight before biospecimens are taken, but little is known about the effects of fasting.

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Article Synopsis
  • Macrophages play a crucial role in the progression of non-alcoholic steatohepatitis (NASH), with specific subsets exhibiting either pro-fibrotic or anti-inflammatory properties in the liver.
  • An iHFC diet with reduced cholic acid (iHFC#2) was found to induce signs of NASH, including inflammation and fibrosis, in C57BL/6 mice, leading to changes in macrophage populations in the liver.
  • The study revealed that different diets and mouse strains affect the types and behavior of macrophages that accumulate in the liver, highlighting the complexity of NASH pathology.
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While brain-derived neurotrophic factor (BDNF), which is a growth factor associated with cognitive improvement and the alleviation of depression symptoms, is known to regulate food intake and body weight, the role of BDNF in peripheral disease is not fully understood. Here, we show that reduced BDNF expression is associated with weight gain and the chronic liver disease non-alcoholic steatohepatitis (NASH). At 10 months of age, BDNF-heterozygous (BDNF ) mice developed symptoms of NASH: centrilobular/perivenular steatosis, lobular inflammation with infiltration of neutrophils, ballooning hepatocytes, and fibrosis of the liver.

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Biopsy is a commonly used method for determining pathological diagnoses by directly using human tissues and cells. Biopsies are widely used to determine disease progression and treatment efficacy. Although organs and tissues are usually obtained by sacrifice during animal experiments, it is theoretically possible to use the same biopsy techniques in humans.

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Erythropoietic protoporphyria (EPP) is a rare inherited disorder of porphyrin metabolism that can cause liver damage and cholestatic hepatocellular failure. We report a case of EPP in a teenaged male who underwent liver biopsy for investigation of liver dysfunction of unknown cause. The diagnosis was not made until a re-biopsy approximately three years later, when the patient presented with recurrent skin lesions and elevated blood and urinary protoporphyrin levels.

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Backgrounds: Nonalcoholic steatohepatitis (NASH) is characterized by fat deposition, inflammation, and hepatocellular damage. The diagnosis of NASH is confirmed pathologically, and hepatocyte ballooning is an important finding for definite diagnosis. Recently, α-synuclein deposition in multiple organs was reported in Parkinson's disease.

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Background: Epidermoid cysts in intrapancreatic accessory spleen (ECIPAS) are a rare lesion. Its pathogenesis, including the origin of cystic epithelium, is not well established. We aimed to elucidate new aspects of the pathological features of ECIPAS to clarify its pathogenesis.

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Radioprotective 105 (RP105) plays a key role in the development of high-fat diet (HFD)-induced metabolic disorders; however, the underlying mechanisms remain to be understood. Here, we aimed to uncover whether RP105 affects metabolic syndrome through the modification of gut microbiota. We confirmed that body weight gain and fat accumulation by HFD feeding were suppressed in Rp105 mice.

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Primary biliary cholangitis (PBC) is a classic autoimmune disease due to the loss of tolerance to self-antigens. Bile acids (BA) reportedly play a major role in biliary inflammation and/or in the modulation of dysregulated immune responses in PBC. Several murine models have indicated that molecular mimicry plays a role in autoimmune cholangitis; however, they have all been limited by the relative failure to develop hepatic fibrosis.

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Despite the clear distinction between cortical (cTECs) and medullary thymic epithelial cells (mTECs) in physiology, the cell of origin of thymic carcinomas (TCs) and other thymic epithelial tumors remained enigmatic. We addressed this issue by focusing on AIRE, an mTEC-specific transcriptional regulator that is required for immunological self-tolerance. We found that a large proportion of TCs expressed AIRE with typical nuclear dot morphology by immunohistochemistry.

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The potential roles of the gut microbiota in the pathogenesis of non-alcoholic fatty liver disease, including non-alcoholic steatohepatitis (NASH), have attracted increased interest. We have investigated the links between gut microbiota and NASH development in Tsumura-Suzuki non-obese mice fed a high-fat/cholesterol/cholate-based (iHFC) diet that exhibit advanced liver fibrosis using antibiotic treatments. The administration of vancomycin, which targets Gram-positive organisms, exacerbated the progression of liver damage, steatohepatitis, and fibrosis in iHFC-fed mice, but not in mice fed a normal diet.

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Macrophages play critical roles in the pathogenesis of non-alcoholic steatohepatitis (NASH). However, it is unclear which macrophage subsets are critically involved in the development of inflammation and fibrosis in NASH. In TSNO mice fed a high-fat/cholesterol/cholate-based diet, which exhibit advanced liver fibrosis that mimics human NASH, we found that Kupffer cells (KCs) were less abundant and recruited macrophages were more abundant, forming hepatic crown-like structures (hCLS) in the liver.

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Nonalcoholic steatohepatitis (NASH) is associated with several cardiovascular risk factors, including atherogenic dyslipidemia. Recently, fasting prior to lipid profile evaluation has been thought to be unnecessary for most individuals. We investigated the impact of fasting for up to 9 h on the serum and hepatic lipid profiles in Sprague-Dawley (SD) rats of dietary-induced NASH model in comparison to SD rats fed a normal diet.

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