RESUMO
Increasing evidence suggests that, in addition to a loss of tolerance, bile acid (BA) modulates the natural history of primary biliary cholangitis (PBC). We focused on the impacts of dietary changes on the immunopathology of PBC, along with alterations in BA composition and gut microbiota. In this study, we have taken advantage of our unique PBC model, a Cyp2c70/Cyp2a12 double knockout (DKO), which includes a human-like BA composition, and develops progressive cholangitis following immunization with the PDC-E2 mimic, 2-octynoic acid (2OA). We compared the effects of a ten-week high-fat diet (HFD) (60 % kcal from fat) and a normal diet (ND) on 2OA-treated DKO mice. Importantly, we report that 2OA-treated DKO mice fed HFD had significantly exacerbated cholangitis, leading to cirrhosis, with increased hepatic expression of Th1 cytokines/chemokines and hepatic fibrotic markers. Serum lithocholic acid (LCA) levels and the ratio of chenodeoxycholic acid (CDCA)-derived BAs to cholic acid-derived BAs were significantly increased by HFD. This was also associated with downregulated expression of key regulators of BA synthesis, including Cyp8b1, Cyp3a11, and Sult2a1. In addition, there were increases in the relative abundances of Acetatifactor and Lactococcus and decreases in Desulfovibrio and Lachnospiraceae_NK4A136_group, which corresponded to the abundances of CDCA and LCA. In conclusion, HFD and HFD-induced alterations in the gut microbiota modulate BA composition and nuclear receptor activation, leading to cirrhotic change in this murine PBC model. These findings have significant implications for understanding the progression of human PBC.
RESUMO
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). Only the condition of long-term chronic (6 months) and high-dose (containing 5% IL in the control diet) administration of IL induced medial thickening in the pulmonary arteries without right ventricular hypertrophy in our rat model. IL administration for a month did not induce pulmonary arterial remodeling but increased endothelin-1 (ET-1) expression levels within endothelial cell (EC) layers in the lungs. Gene Expression Omnibus analysis showed that ET-1 is a key regulator of PAH and that the IL component indican and its metabolite IS induced ET-1 mRNA expression via reactive oxygen species-dependent mechanism. We identified the roles of indican and IS in ET-1 expression in ECs, which were linked to pulmonary arterial remodeling in an animal model.
Assuntos
Endotelina-1 , Hipertrofia Ventricular Direita , Folhas de Planta , Artéria Pulmonar , Ratos Sprague-Dawley , Remodelação Vascular , Animais , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , Artéria Pulmonar/patologia , Masculino , Endotelina-1/metabolismo , Remodelação Vascular/efeitos dos fármacos , Hipertrofia Ventricular Direita/metabolismo , Hipertrofia Ventricular Direita/fisiopatologia , Hipertensão Pulmonar/induzido quimicamente , Hipertensão Pulmonar/metabolismo , Ratos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/patologia , Pulmão/metabolismoRESUMO
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. The expression levels of inflammation- and fibrosis-related genes in the liver significantly increased after VCM treatment for 8 weeks. F4/80+ macrophage abundance increased in the livers of VCM-treated mice. These changes were rarely observed in the iHFC#2-fed C57BL/6 mice treated with metronidazole, which targets anaerobic bacteria. A16S rRNA sequence analysis revealed a significant decrease in α-diversity in VCM-treated mice compared with that in placebo-treated mice, with Bacteroidetes and Firmicutes significantly decreased, while Proteobacteria and Verrucomicrobia increased markedly. Finally, VCM treatment dramatically altered the level and balance of bile acid (BA) composition in iHFC#2-fed C57BL/6 mice. Thus, the VCM-mediated exacerbation of MASH progression depends on the interaction between the gut microbiota, BA metabolism, and inflammatory responses in the livers of iHFC#2-fed C57BL/6 mice.
Assuntos
Antibacterianos , Dieta Hiperlipídica , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Vancomicina , Animais , Microbioma Gastrointestinal/efeitos dos fármacos , Camundongos , Antibacterianos/farmacologia , Masculino , Vancomicina/farmacologia , Dieta Hiperlipídica/efeitos adversos , Fígado/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/etiologia , Ácidos e Sais Biliares/metabolismoRESUMO
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. METHODS: We analyzed differences in the immune system, gut microbiota, and bile acid metabolism in TSNO and TSOD mice fed with a normal diet (ND) or an iHFC diet. RESULTS: TSOD mice had more anti-inflammatory macrophages in the liver than TSNO mice under ND feeding, and were impaired in the iHFC diet-induced accumulation of fibrosis-associated macrophages and formation of histological hepatic crown-like structures in the liver. The gut microbiota of TSOD mice also exhibited a distinct community composition with lower diversity and higher abundance of Akkermansia muciniphila compared with that in TSNO mice. Finally, TSOD mice had lower levels of bile acids linked to intestinal barrier disruption under iHFC feeding. CONCLUSIONS: The dynamics of liver macrophage subsets, and the compositions of the gut microbiota and bile acids at steady state and post-onset of MASH, had major impacts on MASH development.
Assuntos
Ácidos e Sais Biliares , Dieta Hiperlipídica , Microbioma Gastrointestinal , Fígado , Macrófagos , Animais , Ácidos e Sais Biliares/metabolismo , Fígado/patologia , Fígado/metabolismo , Dieta Hiperlipídica/efeitos adversos , Macrófagos/metabolismo , Macrófagos/imunologia , Masculino , Camundongos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Fígado Gorduroso/microbiologia , Akkermansia , Progressão da Doença , Colesterol na Dieta/efeitos adversosRESUMO
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. Interestingly, BDNF is also expressed in the hypothalamus in appetite and energy metabolism. Previous reports demonstrated that BDNF knockout mice exhibited overeating and obesity phenotypes remarkably. Therefore, we could raise a hypothesis that the loss of function of BDNF may be associated with metabolic syndrome and peripheral diseases. In this review, we describe our recent finding that BDNF knockout mice develop metabolic dysfunction-associated steatohepatitis and recent reports demonstrating the role of one of the BDNF receptors, TrkB-T1, in some peripheral organ functions and diseases, and would provide an insight into the role of BDNF beyond the brain.
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Animais , Humanos , Receptor trkB/metabolismo , Receptor trkB/genética , Camundongos , Camundongos Knockout , Metabolismo Energético/genética , Obesidade/metabolismo , Obesidade/genética , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Liver fibrosis is assessed mainly by conventional staining or second harmonic generation (SHG) microscopy, which can only provide collagen content in fibrotic area. We propose to use polarization-resolved SHG (PR-SHG) microscopy to quantify liver fibrosis in terms of collagen fiber orientation and crystallization. Liver samples obtained from autopsy cases with fibrosis stage of F0-F4 were evaluated with an SHG microscope, and 12 consecutive PR-SHG images were acquired while changing the polarization azimuth angle of the irradiated laser from 0° to 165° in 15° increments using polarizer. The fiber orientation angle (φ) and degree (ρ) of collagen were estimated from the images. The SHG-positive area increased as the fibrosis stage progressed, which was well consistent with Sirius Red staining. The value of φ was random regardless of fibrosis stage. The mean value of ρ (ρ-mean), which represents collagen fiber crystallinity, varied more as fibrosis progressed to stage F3, and converged to a significantly higher value in F4 than in other stages. Spatial dispersion of ρ (ρ-entropy) also showed increased variation in the stage F3 and decreased variation in the stage F4. It was shown that PR-SHG could provide new information on the properties of collagen fibers in human liver fibrosis.
Assuntos
Microscopia de Geração do Segundo Harmônico , Humanos , Microscopia de Geração do Segundo Harmônico/métodos , Colágeno , Cirrose Hepática , Refração Ocular , CorantesRESUMO
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. Here, we investigated the impact of overnight fasting for approximately 9 to 17 h on glucose and lipid metabolism in a Sprague-Dawley (SD) rat model of diet-induced moderate and advanced NASH in comparison to normal SD rats. Our results revealed that in the moderate NASH model rats, the fasting duration did not affect glucose and lipid metabolism, the histopathological findings, or the hepatic mRNA expression levels of genes related to lipid metabolism, cholesterol metabolism, inflammation, fibrosis, and oxidative stress. In contrast, in the normal rats, significant fasting time-dependent reductions were observed in the epididymal fat pad weight and the hepatic mRNA expression levels of adipose differentiation-related protein and heme oxygenase-1. Moreover, in the advanced NASH model rats, a significant fasting time-dependent reduction and increase were observed in the serum insulin level and mRNA expression level of alpha-smooth muscle actin, respectively. Our present results suggest that the influence of the overnight fasting duration differs among the healthy condition, moderate NASH, and advanced NASH statuses. Further studies are needed in humans to determine the appropriate overnight fasting duration for the accurate evaluation of glucose and lipid metabolism in NASH patients.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Ratos , Animais , Hepatopatia Gordurosa não Alcoólica/etiologia , Ratos Sprague-Dawley , Glucose/metabolismo , Metabolismo dos Lipídeos , Dieta Hiperlipídica , Fígado/metabolismo , Cirrose Hepática/patologia , Jejum , RNA Mensageiro/metabolismo , Modelos Animais de DoençasRESUMO
Macrophages are critical for the development of non-alcoholic steatohepatitis (NASH). Our previous findings in TSNO mouse livers showed that an iHFC (high-fat/cholesterol/cholate) diet induced liver fibrosis similar to human NASH and led to the accumulation of distinct subsets of macrophage: CD11c+/Ly6C- and CD11c-/Ly6C+ cells. CD11c+/Ly6C- cells were associated with the promotion of advanced liver fibrosis in NASH. On the other hand, CD11c-/Ly6C+ cells exhibited an anti-inflammatory effect and were involved in tissue remodeling processes. This study aimed to elucidate whether an iHFC diet with reduced cholic acid (iHFC#2 diet) induces NASH in C57BL/6 mice and examine the macrophage subsets accumulating in the liver. Histological and quantitative real-time PCR analyses revealed that the iHFC#2 diet promoted inflammation and fibrosis indicative of NASH in the livers of C57BL/6 mice. Cell numbers of Kupffer cells decreased and recruited macrophages were accumulated in the livers of iHFC#2 diet-fed C57BL/6 mice. Notably, the iHFC#2 diet resulted in the accumulation of three macrophage subsets in the livers of C57BL/6 mice: CD11c+/Ly6C-, CD11c-/Ly6C+, and CD11c+/Ly6C+ cells. However, CD11c+/Ly6C+ cells were not distinct populations in the iHFC-fed TSNO mice. Thus, differences in cholic acid content and mouse strain affect the macrophage subsets that accumulate in the liver.
RESUMO
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. Obesity and higher serum levels of glucose and insulin - major pathologic features in human NASH - were dramatic. Dying adipocytes were surrounded by macrophages in visceral fat, suggesting that chronic inflammation occurs in peripheral organs. RNA sequencing (RNA-seq) studies of the liver revealed that the most significantly enriched Gene Ontology term involved fatty acid metabolic processes and the modulation of neutrophil aggregation, pathologies that well characterise NASH. Gene expression analysis by RNA-seq also support the notion that BDNF+/- mice are under oxidative stress, as indicated by alterations in the expression of the cytochrome P450 family and a reduction in glutathione S-transferase p, an antioxidant enzyme. Histopathologic phenotypes of NASH were also observed in a knock-in mouse (BDNF+/pro ), in which the precursor BDNF is inefficiently converted into the mature form of BDNF. Lastly, as BDNF reduction causes overeating and subsequent obesity, a food restriction study was conducted in BDNF+/pro mice. Pair-fed BDNF+/pro mice developed hepatocellular damage and showed infiltration of inflammatory cells, including neutrophils in the liver, despite having body weights and blood parameters that were comparable to those of controls. This is the first report demonstrating that reduced BDNF expression plays a role in the pathogenic mechanism of NASH, which is a hepatic manifestation of metabolic syndrome. © 2023 The Pathological Society of Great Britain and Ireland.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Camundongos Knockout , Fígado/patologia , Inflamação/patologia , Obesidade/complicações , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Dieta HiperlipídicaRESUMO
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. In the present study, we examined the feasibility of performing four repeated liver biopsies in a spontaneous metabolic syndrome mouse model. Even though a small number of mice died accidently, most mice were able to undergo four liver biopsies without significant adverse events. We also performed three liver biopsies in mouse liver tumor carcinogen models at 4, 8, and 12 weeks of age. In addition to the sample collected at 16 weeks of age during sacrifice, we successfully collected four liver samples from the same mice at different stages of disease progression. The application of this liver biopsy technique might make it possible for direct evaluation of pathological conditions in the same individual over time, thereby reducing the number of experimental animals.
RESUMO
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. METHODS: Six cases of ECIPAS were included in this study. As well as histopathological analysis, to elucidate the features and nature of cystic epithelial cells, immunohistochemical analysis including Pbx1 and Tlx1 and imaging mass spectrometry was performed. RESULTS: Histologically, the cysts were covered by either monolayered or multilayered epithelium. Immunohistochemistry revealed that the epithelial cells in multilayered epithelium exhibited different attributes between the basal and superficial layers. Few epithelial cells had abundant clear cytoplasm and were immunohistochemically positive for adipophilin, suggesting lipid-excreting function. The intracystic fluid contained cholesterol clefts and foamy macrophages, and imaging mass spectrometry revealed the accumulation of lipids. Immunohistochemical analysis indicated that the epithelial cells were positive for Pbx1 in some cases. CONCLUSION: Novel histological features of epithelial cells of ECIPAS were indicated. Although more cases need to be evaluated, we propose that the cause of ECIPAS may be different from that of pancreatic ductal origin. J. Med. Invest. 70 : 251-259, February, 2023.
Assuntos
Cisto Epidérmico , Pancreatopatias , Humanos , Cisto Epidérmico/patologia , Baço/patologia , Pancreatopatias/patologia , Células Epiteliais , Imuno-HistoquímicaRESUMO
BACKGROUND: Non-alcoholic steatohepatitis (NASH) is associated with a higher risk of hepatocellular carcinoma (HCC), and the importance of the gut?liver axis has been recognized in NASH-associated HCC. We investigated the effect of TU-100 on the intestinal microbiome and hepatocarcinogenesis in a NASH model. METHODS: Seven-week-old Tsumura Suzuki obese diabetes mice, a model that shows the spontaneous onset of NASH and HCC, were used. They were divided into a TU-100 treated group and a control group. Mice were sacrificed at 24 and 48 weeks to evaluate hepatic steatosis, fibrosis, carcinogenesis, cytokine expression, and microbiome abundance. RESULTS: At 24 weeks, the TU-100 group showed significantly lower expression of IL6, IL1B, and ACTA2 mRNA in the liver (P?0.05). At 48 weeks, the TU-100 group showed significantly lower levels of serum alanine aminotransferase. The TU-100 group also showed a lower rate of NASH than the control group (28% vs 72%?;?P?=?0.1). Tumor diameter was significantly smaller in the TU-100 group compared with that in the control group (P?0.05). Regarding the intestinal microbiome, the genera Blautia and Ruminococcus were increased in the TU-100 group (P?0.05), whereas Dorea and Erysipelotrichaceae were decreased in the TU-100 group (P?0.05). CONCLUSIONS: TU-100 regulates the intestinal microbiome and may suppress subsequent hepatocarcinogenesis in the NASH model. J. Med. Invest. 70 : 66-73, February, 2023.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/etiologia , Fígado , Carcinogênese/metabolismo , Carcinogênese/patologiaRESUMO
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. The liver biopsies contained brownish deposits that exhibited birefringence under polarized light and porphyrin fluorescence under fluorescence spectroscopy. EPP should be considered in young patients with unexplained liver dysfunction, skin symptoms, and seasonal changes in symptoms. Fluorescence spectroscopy of liver biopsy tissue can be a useful tool in the diagnosis of EPP.
RESUMO
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. Since it was reported that α-synuclein is taken up by hepatocytes via connexin 32, the expression of α-synuclein in the liver in NASH is of interest. The accumulation of α-synuclein in the liver in NASH was investigated. Immunostaining for p62, ubiquitin, and α-synuclein was performed, and the usefulness of immunostaining in pathological diagnosis was examined. METHODS: Liver biopsy tissue specimens from 20 patients were evaluated. Several antibodies against α-synuclein, as well as antibodies against connexin 32, p62, and ubiquitin were used for immunohistochemical analyses. Staining results were evaluated by several pathologists with varying experience, and the diagnostic accuracy of ballooning was compared. RESULTS: Polyclonal α-synuclein antibody, not the monoclonal antibody, reacted with eosinophilic aggregates in ballooning cells. Expression of connexin 32 in degenerating cells was also demonstrated. Antibodies against p62 and ubiquitin also reacted with some of the ballooning cells. In the pathologists' evaluations, the highest interobserver agreement was obtained with hematoxylin and eosin (H&E)-stained slides, followed by slides immunostained for p62 and α-synuclein, and there were cases with different results between H&E staining and immunostaining CONCLUSION: These results indicate the incorporation of degenerated α-synuclein into ballooning cells, suggesting the involvement of α-synuclein in the pathogenesis of NASH. The combination of immunostaining including polyclonal α-synuclein may contribute to improving the diagnosis of NASH.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/patologia , alfa-Sinucleína/metabolismo , Fígado/patologia , Hepatócitos/metabolismo , Ubiquitinas/metabolismoRESUMO
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. Fecal microbiome transplantation from HFD-fed donor Rp105-/- mice into HFD-fed recipient wild-type mice significantly improved various abnormalities associated with metabolic syndrome, including body weight gain, insulin resistance, hepatic steatosis, macrophage infiltration and inflammation in the adipose tissue. In addition, HFD-induced intestinal barrier dysfunction was attenuated by fecal microbiome transplantation from HFD-fed donor Rp105-/- mice. A 16S rRNA sequence analysis indicated that RP105 modified gut microbiota composition and was involved in the maintenance of its diversity. Thus, RP105 promotes metabolic syndrome by altering gut microbiota composition and intestinal barrier function.
Assuntos
Microbioma Gastrointestinal , Síndrome Metabólica , Animais , Camundongos , Obesidade/metabolismo , Microbioma Gastrointestinal/fisiologia , RNA Ribossômico 16S/genética , Dieta Hiperlipídica/efeitos adversos , Aumento de Peso , Imunidade Inata , Camundongos Endogâmicos C57BLRESUMO
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. AIRE expression in TCs was supported by the RNA-seq data in the TCGA-THYM database. Furthermore, our bioinformatics approach to the recent single-cell RNA-seq data on human thymi has revealed that TCs hold molecular characteristics of multiple mTEC subpopulations. In contrast, TCs lacked the gene signatures for cTECs. We propose that TCs are tumors derived from mTECs.
Assuntos
Timoma , Neoplasias do Timo , Humanos , Diferenciação Celular/genética , Células Epiteliais/metabolismo , Timoma/patologia , Timo , Neoplasias do Timo/genética , Neoplasias do Timo/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína AIRERESUMO
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. We hypothesized that species-specific differences in the BA composition between mice and humans were the primary reason for this limited pathology. Here, we aimed to study the impact of human-like hydrophobic BA composition on the development of autoimmune cholangitis and hepatic fibrosis. We took advantage of a unique construct, Cyp2c70/Cyp2a12 double knockout (DKO) mice, which have human-like BA composition, and immunized them with a well-defined mimic of the major mitochondrial autoantigen of PBC, namely 2-octynoic acid (2OA). 2OA-treated DKO mice were significantly exacerbated portal inflammation and bile duct damage with increased Th1 cytokines/chemokines at 8 weeks post-initial immunization. Most importantly, there was clear progression of hepatic fibrosis and increased expression of hepatic fibrosis-related genes. Interestingly, these mice demonstrated increased serum BA concentrations and decreased biliary BA concentrations; hepatic BA levels did not increase because of the upregulation of transporters responsible for the basolateral efflux of BA. Furthermore, cholangitis and hepatic fibrosis were more advanced at 24 weeks post-initial immunization. These results indicate that both the loss of tolerance and the effect of hydrophobic BA are essential for the progression of PBC.
Assuntos
Doenças Autoimunes , Colangite , Cirrose Hepática Biliar , Humanos , Animais , Camundongos , Ácidos e Sais Biliares , Cirrose Hepática , Inflamação , Autoantígenos , Modelos Animais de DoençasRESUMO
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. F4/80+-recruited macrophages were more abundant in the liver of vancomycin-treated iHFC-fed mice. The infiltration of CD11c+-recruited macrophages into the liver, forming hepatic crown-like structures, was enhanced by vancomycin treatment. The co-localization of this macrophage subset with collagen was greatly augmented in the liver of vancomycin-treated iHFC-fed mice. These changes were rarely seen with the administration of metronidazole, which targets anaerobic organisms, in iHFC-fed mice. Finally, the vancomycin treatment dramatically modulated the level and composition of bile acid in iHFC-fed mice. Thus, our data demonstrate that changes in inflammation and fibrosis in the liver by the iHFC diet can be modified by antibiotic-induced changes in gut microbiota and shed light on their roles in the pathogenesis of advanced liver fibrosis.
Assuntos
Antibacterianos , Ácidos e Sais Biliares , Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica , Vancomicina , Animais , Camundongos , Antibacterianos/farmacologia , Ácidos e Sais Biliares/metabolismo , Dieta Hiperlipídica , Modelos Animais de Doenças , Microbioma Gastrointestinal/efeitos dos fármacos , Fígado/metabolismo , Cirrose Hepática/metabolismo , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , Vancomicina/farmacologiaRESUMO
BACKGROUND: The incidence of non-alcoholic steatohepatitis (NASH) is dramatically increasing, but the effect of NASH on colon cancer liver metastasis (CLM) is controversial. The aim of this study was to investigate the impact and mechanism of action of NASH on CLM using a western diet (WD)-fed mouse model. METHODS: Six-week-old male C57BL/6 J mice were used. They were divided into the WD group and control group with normal diet. MC38 colon cancer cells were injected into the spleen at 2, 6, 8 and 16 weeks, and mice were killed at 2 weeks after injection to evaluate hepatic steatosis, fibrosis, metastasis and mRNA/protein expression in the liver. RESULTS: Only mice fed a WD for 16 weeks showed hepatic fibrosis. These mice showed significantly higher alanine aminotransferase and total cholesterol levels compared with the control group (p < 0.05). The WD group showed significantly lower tumor number and smaller tumor diameter (p < 0.05). In the WD group, expression of SAA1, IL6, STAT3 and MMP9 mRNA in the liver was significantly lower than in the control group (p < 0.05). Serum amyloid A1 protein expression was also lower in the WD group. CONCLUSIONS: The WD-fed NASH mouse model showed an inhibitory effect on CLM. Suppressed interleukin-6/signal transducer and activator of transcription 3 signaling and serum amyloid A/matrix metalloproteinase 9 expression may affect this phenomenon.
Assuntos
Neoplasias do Colo , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Masculino , Camundongos , Animais , Camundongos Endogâmicos C57BL , Fígado/patologia , Neoplasias Hepáticas/patologia , Modelos Animais de Doenças , Neoplasias do Colo/patologia , RNA Mensageiro/metabolismoRESUMO
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. The recruited macrophages comprised two subsets: CD11c+/Ly6C- and CD11c-/Ly6C+ cells. CD11c+ cells were present in a mesh-like pattern around the lipid droplets, constituting the hCLS. In addition, CD11c+ cells colocalized with collagen fibers, suggesting that this subset of recruited macrophages might promote advanced liver fibrosis. In contrast, Ly6C+ cells were present in doughnut-like inflammatory lesions, with a lipid droplet in the center. Finally, RNA sequence analysis indicates that CD11c+/Ly6C- cells promote liver fibrosis and hepatic stellate cell (HSC) activation, whereas CD11c-/Ly6C+ cells are a macrophage subset that play an anti-inflammatory role and promote tissue repair in NASH. Taken together, our data revealed changes in liver macrophage subsets during the development of NASH and shed light on the roles of the recruited macrophages in the pathogenesis of advanced fibrosis in NASH.