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Background and Aims: Recent studies showed that patients suffering from lysosomal acid lipase deficiency (LAL-D) benefit from enzyme replacement therapy; however, liver histopathology improved in some but not all patients. We hypothesized that the pan-peroxisome proliferator-activated receptor agonist lanifibranor may have beneficial effects on liver inflammation in LAL knockout (Lal-/-) mice based on its promising results in alleviating liver inflammation in patients with metabolic dysfunction-associated steatohepatitis. Methods: Female Lal-/- mice were daily gavaged with lanifibranor or vehicle for 21 days. The effects of the treatment were assessed by measuring body and organ weights, plasma lipids and lipoproteins, as well as hematological parameters, followed by liver proteomics and metabolomics. Results: Lanifibranor treatment slightly altered organ weights without affecting the total body weight of Lal-/- mice. We observed major changes in the proteome, with multiple proteins related to lipid metabolism, peroxisomal, and mitochondrial activities being upregulated and inflammation-related proteins being downregulated in the livers of treated mice. Hepatic lipid levels and histology remained unaltered, whereas plasma triacylglycerol and total cholesterol levels were decreased and the lipoprotein profile of lanifibranor-treated Lal-/- mice improved. Conclusion: Lanifibranor treatment positively affected liver inflammation and dyslipidemia in Lal-/- mice. These findings suggest the necessity of a further combined study of lanifibranor with enzyme replacement therapy in Lal-/- mice to improve the phenotype. Moreover, there is a compelling rationale for conducting clinical trials to assess the efficacy of lanifibranor as a potential treatment option for LAL-D in humans.
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Rationale: Dysregulated T-cell immune response-mediated inflammation plays critical roles in the pathology of diverse liver diseases, but the underlying mechanism of liver immune homeostasis control and the specific therapies for limiting T-cell overactivation remain unclear. Methods: The metabolic changes in concanavalin A (ConA) mice and autoimmune hepatitis (AIH) patients and their associations with liver injury were analyzed. The expression of purine catabolism nucleases (e.g., CD39 and CD73) on liver cells and immune cells was assessed. The effects of MCregs and their extracellular vesicles (EVs) on CD4+ T-cell overactivation and the underlying mechanism were also explored. Results: Our findings revealed significant alterations in purine metabolism in ConA mice and AIH patients, which correlated with liver injury severity and therapeutic response. CD39 and CD73 were markedly upregulated on CD11b+Gr-1+ MCs under liver injury conditions. The naturally expanded CD39+CD73+Gr-1highCD11b+ MCreg subset during early liver injury effectively suppressed CD4+ T-cell hyperactivation and liver injury both in vitro and in vivo. Mechanistically, MCregs released CD73high EVs, which converted extracellular AMP to immunosuppressive metabolites (e.g., adenosine and inosine), activating the cAMP pathway and inhibiting glycolysis and cytokine secretion in activated CD4+ T cells. Conclusions: This study provides insights into the mechanism controlling immune homeostasis during the early liver injury phase and highlights that MCreg or MCreg-EV therapy may be a specific strategy for preventing diverse liver diseases induced by T-cell overactivation.
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Vesículas Extracelulares , Hepatitis Autoinmune , Ratones Endogámicos C57BL , Purinas , Animales , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/inmunología , Ratones , Purinas/metabolismo , Hepatitis Autoinmune/inmunología , Hepatitis Autoinmune/metabolismo , Hepatitis Autoinmune/patología , Humanos , Apirasa/metabolismo , Hígado/metabolismo , Hígado/inmunología , Hígado/patología , Células Mieloides/metabolismo , Células Mieloides/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Masculino , 5'-Nucleotidasa/metabolismo , Activación de Linfocitos/inmunología , Concanavalina A , Femenino , Modelos Animales de Enfermedad , Inflamación/metabolismo , Inflamación/inmunología , Antígenos CDRESUMEN
Stimulator of interferon genes (STING) is positively correlated with the degrees of liver inflammation in human metabolic dysfunction-associated steatotic liver disease (MASLD). In addition, STING disruption alleviates MASLD in mice fed a high-fat diet (HFD) for 3 months (3-m-HFD). Here we investigated the role of the duration of dietary feeding in regulating MASLD in mice and explored the involvement of STING in sex differences in MASLD. Both male and female STING-disrupted (STINGgt) and wild-type C57BL/6J mice were fed an HFD for 3 or 7 months (7-m-HFD). Additionally, female STINGgt mice upon ovariectomy (OVX) and 3-m-HFD were analyzed for MASLD. Upon 3-m-HFD, STINGgt mice exhibited decreased severity of MASLD compared to control. However, upon 7-m-HFD, STINGgt mice were comparable with wild-type mice in body weight, fat mass, and MASLD. Regarding regulating the liver RNA transcriptome, 7-m-HFD increased the expression of genes indicating proinflammatory activation of various liver cells. Interestingly, the severity of MASLD in female mice was much lighter than in male mice, regardless of STING disruption. Upon OVX, female STINGgt mice showed significantly increased severity of MASLD relative to sham control but were comparable with male STINGgt mice. Upon treatment with 17-beta estradiol (E2), hepatocytes revealed decreased fat deposition while macrophages displayed decreases in lipopolysaccharide-induced phosphorylation of Nfkb p65 and Jnk p46 independent of STING. These results suggest that 7-m-HFD, without altering female sex-based protection, abolishes STING disruption-driven protection of MASLD, likely through causing proinflammatory activation of multiple types of liver cells to offset the effect of STING disruption.
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Hepatitis B Virus (HBV) is a stealthy and insidious pathogen capable of inducing chronic necro-inflammatory liver disease and hepatocellular carcinoma (HCC), resulting in over one million deaths worldwide per year. The traditional understanding of Chronic Hepatitis B (CHB) progression has focused on the complex interplay among ongoing virus replication, aberrant immune responses, and liver pathogenesis. However, the dynamic progression and crucial factors involved in the transition from HBV infection to immune activation and intrahepatic inflammation remain elusive. Recent insights have illuminated HBV's exploitation of the sodium taurocholate co-transporting polypeptide (NTCP) and manipulation of the cholesterol transport system shared between macrophages and hepatocytes for viral entry. These discoveries deepen our understanding of HBV as a virus that hijacks hepatocyte metabolism. Moreover, hepatic niche macrophages exhibit significant phenotypic and functional diversity, zonal characteristics, and play essential roles, either in maintaining liver homeostasis or contributing to the pathogenesis of chronic liver diseases. Therefore, we underscore recent revelations concerning the importance of hepatic niche macrophages in the context of viral hepatitis. This review particularly emphasizes the significant role of HBV-induced metabolic changes in hepatic macrophages as a key factor in the transition from viral infection to immune activation, ultimately culminating in liver inflammation. These metabolic alterations in hepatic macrophages offer promising targets for therapeutic interventions and serve as valuable early warning indicators, shedding light on the disease progression.
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Virus de la Hepatitis B , Hepatitis B Crónica , Hígado , Macrófagos , Humanos , Virus de la Hepatitis B/inmunología , Virus de la Hepatitis B/fisiología , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/virología , Animales , Hígado/inmunología , Hígado/virología , Hígado/metabolismo , Hígado/patología , Hepatitis B Crónica/inmunología , Hepatitis B Crónica/metabolismo , Hepatitis B Crónica/virología , Inflamación/inmunología , Inflamación/metabolismo , Hepatocitos/metabolismo , Hepatocitos/inmunología , Hepatocitos/virologíaRESUMEN
Background: This study aimed to investigate the effects of licorice processing of different Evodiae Fructus (EF) specifications on liver inflammation and oxidative stress associated with the intestinal mucosal microbiota. Materials and methods: The 25 Kunming mice were divided into control (MCN), raw small-flowered Evodiae Fructus (MRSEF), raw medium-flowered EF (MRMEF), licorice-processed small-flowered EF (MLSEF), and licorice-processed medium-flowered EF (MLSEF) groups. The EF intervention groups were given different specifications of EF extract solutions by gavage. After 21 days, indices of liver inflammation and oxidative stress and intestinal mucosal microbiota were measured in mice. Results: Compared with the MCN, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels were significantly increased in the MRMEF. Although the trends of oxidative stress and inflammatory indexes in the MLSEF and MLMEF were consistent with those in the raw EF groups, the changes were smaller than those in the raw EF groups. Compared to the raw EF groups, the MLSEF and MLMEF showed closer approximations of metabolic function to the MCN. The abundance of Corynebacterium in MRMEF was significantly lower than that in the MCN, and it was not significantly different from the MCN after licorice processing. The probiotic Candidatus Arthromitus was enriched in the MLSEF. The probiotic Lactobacillus was enriched in the MLMEF. Correlation analysis revealed significant negative correlations between IL-1ß, some metabolic functions and Corynebacterium. Conclusion: The effects of medium-flowered EF on oxidative stress and inflammatory factors in the liver of mice were stronger than those of small-flowered EF. The licorice processing can reduce this difference by modulating the abundance of Corynebacterium and intestinal mucosal metabolic function.
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Inflammation responses have identified as a key mediator of in various liver diseases with high morbidity and mortality. cGAS-STING signalling is essential in innate immunity since it triggers release of type I interferons and various of proinflammatory cytokines. The potential connection between cGAS-STING pathway and liver inflammatory diseases has recently been reported widely. In our review, the impact of cGAS-STING on liver inflammation and regulatory mechanism are summarized. Furthermore, many inhibitors of cGAS-STING signalling as promising agents to cure liver inflammation are also explored in detail. A comprehensive knowledge of molecular mechanisms of cGAS-STING signalling in liver inflammation is vital for exploring novel treatments and providing recommendations and perspectives for future utilization.
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Inmunidad Innata , Hepatopatías , Proteínas de la Membrana , Nucleotidiltransferasas , Transducción de Señal , Humanos , Nucleotidiltransferasas/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/inmunología , Transducción de Señal/inmunología , Hepatopatías/metabolismo , Hepatopatías/inmunología , Animales , Interferón Tipo I/metabolismo , Interferón Tipo I/inmunologíaRESUMEN
BACKGROUND: The molecular mediators responsible for the progression of metabolic dysfunction-associated steatotic liver disease (MASLD) to steatohepatitis (MASH) have not yet been completely disentangled. We sought to analyze whether FNDC4, an hepatokine and adipokine with anti-inflammatory properties, is involved in TNF-α-induced inflammatory cell death in patients with MASLD. METHODS: Plasma FNDC4 (n = 168) and hepatic FNDC4 and inflammatory cell death (n = 65) were measured in samples from patients with severe obesity with available liver biopsy-proven MASLD diagnosis. The effect of FNDC4 on TNF-α-induced pyroptosis, apoptosis and necroptosis (PANoptosis) and mitochondrial dysfunction was studied in vitro using human HepG2 hepatocytes. RESULTS: Compared with individuals with normal liver, patients with type 2 diabetes and MASLD exhibited decreased hepatic FNDC4 mRNA and protein levels, which were related to liver inflammation. An overexpression of TNF-α, its receptor TNF-R1 and factors involved in inflammatory cell death was also found in the liver of these patients. FNDC4-knockdown in HepG2 hepatocytes increased apoptotic cell death, while FNDC4 treatment blunted NLRP3 inflammasome-induced pyroptosis, apoptosis and necroptosis in TNF-α-stimulated hepatocytes. Moreover, FNDC4 improved TNF-α-induced hepatocyte mitochondrial dysfunction by enhancing mitochondrial DNA (mtDNA) copy number and OXPHOS complex subunits I, II, III and V protein expression. Mechanistically, AMP-activated protein kinase α (AMPKα) was required for the FNDC4-mediated inhibition of cell death and increase in mtDNA content. CONCLUSIONS: FNDC4 acts as a hepatocyte survival factor favouring mitochondrial homeostasis and decreasing inflammatory cell death via AMPKα. Collectively, our study identifies FNDC4 as an attractive target to prevent hepatocellular damage in patients with MASLD.
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Proteínas Quinasas Activadas por AMP , Hepatocitos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Quinasas Activadas por AMP/metabolismo , Apoptosis/efectos de los fármacos , Muerte Celular , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/metabolismo , Hígado Graso/metabolismo , Fibronectinas/metabolismo , Células Hep G2 , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Inflamación/metabolismo , Hígado/metabolismo , Hígado/patología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Apoptosis, inflammation, and wound healing are critical pathophysiological events associated with various liver diseases. Currently, there is a lack of in vivo approaches to study hepatocyte apoptosis-induced liver injury and repair. To address this critical knowledge gap, we developed a unique genetically modified mouse model, namely, 3-Transgene (Tg) with inducible Hepatocyte-Specific Apoptosis Phenotype (3xTg-iHAP) in this study. The 3xTg-iHAP mice possess three transgenes including Alb-Cre, Rosa26-rtTA, and tetO-Fasl on a B6 background. These mice are phenotypically normal, viable, and fertile. After subcutaneous administration of a single dose of doxycycline (5 mg/kg, Dox) to 3xTg-iHAP mice, we observed a complete histological spectrum of sterile liver wound-healing responses: asymptomatic hepatocyte apoptosis at 8 h, necrotic liver injury and sterile inflammation at 48 h, followed by hepatocyte mitosis and regeneration within 7 days. During the injury phase, the mice exhibited an increase in the biomarkers of alanine aminotransferase (ALT), chemokine (C-X-C motif) ligand 1 (CXCL1), and IL-6 in peripheral blood, as well as α-smooth muscle actin (α-SMA) protein in liver tissues. Conversely, the mice displayed a decrease in these markers in the recovery phase. Remarkably, this model shows that the sterile liver injury following elevated hepatocyte apoptosis is associated with an increase in myeloid cells in the liver. Within 7 days post-Dox administration, the liver of Dox-treated 3xTg-iHAP mice displays a normal histological structure, indicating the completion of wound healing. Together, we established a novel mouse model of injury and regeneration induced by hepatocyte apoptosis. This tool provides a robust in vivo platform for studying the pathophysiology of sterile liver inflammation, regeneration, and new therapeutic interventions for liver diseases.NEW & NOTEWORTHY Bu et al. present a triple-transgenic mouse model, namely, 3xTg-iHAP mice that are engineered to explore hepatocyte apoptosis-triggered sterile liver injury and regeneration. This model demonstrates a full spectrum of liver wound-healing responses from asymptomatic apoptosis to injury, myeloid cell-dominant sterile inflammation, and repair after induction of hepatocyte-specific apoptosis. The robust nature of this model makes it an invaluable in vivo tool for studying sterile liver inflammation, regeneration, and new therapeutic strategies.
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Apoptosis , Modelos Animales de Enfermedad , Hepatocitos , Regeneración Hepática , Ratones Transgénicos , Células Mieloides , Animales , Hepatocitos/metabolismo , Hepatocitos/patología , Ratones , Células Mieloides/metabolismo , Hígado/metabolismo , Hígado/patología , Cicatrización de Heridas , Ratones Endogámicos C57BL , Quimiocina CXCL1/metabolismo , Quimiocina CXCL1/genéticaRESUMEN
Hepatic fibrosis is a common pathology present in most chronic liver diseases. Autophagy is a lysosome-mediated intracellular catabolic and recycling process that plays an essential role in maintaining normal hepatic functions. Nuclear factor erythroid 2-like 2 (Nrf2) is a transcription factor responsible for the regulation of cellular anti-oxidative stress response. This study was designed to assess the cytoprotective effect of mesenchymal stem cell-derived exosomes (MSC-exos) on endothelial-mesenchymal transition (EMT) in Carbon Tetrachloride (CCL4) induced liver fibrosis. Rats were treated with 0.1 ml of CCL4 twice weekly for 8 weeks, followed by administration of a single dose of MSC-exos. Rats were then sacrificed after 4 weeks, and liver samples were collected for gene expression analyses, Western blot, histological studies, immunohistochemistry, and transmission electron microscopy. Our results showed that MSC-exos administration decreased collagen deposition, apoptosis, and inflammation. Exosomes modulate the Nrf2/Keap1/p62 pathway, restoring autophagy and Nrf2 levels through modulation of the non-canonical pathway of Nrf2/Keap1/p62. Additionally, MSC-exos regulated miR-153-3p, miR-27a, miR-144 and miRNA-34a expression. In conclusion, the present study shed light on MSC-exos as a cytoprotective agent against EMT and tumorigenesis in chronic liver inflammation.
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Tetracloruro de Carbono , Exosomas , Proteína 1 Asociada A ECH Tipo Kelch , Cirrosis Hepática , Células Madre Mesenquimatosas , MicroARNs , Factor 2 Relacionado con NF-E2 , Transducción de Señal , Animales , Exosomas/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Células Madre Mesenquimatosas/metabolismo , Cirrosis Hepática/patología , Cirrosis Hepática/metabolismo , Cirrosis Hepática/terapia , Masculino , Ratas , MicroARNs/metabolismo , MicroARNs/genética , Ratas Sprague-Dawley , Hígado/patología , Hígado/metabolismo , Autofagia , Proteína Sequestosoma-1/metabolismoRESUMEN
Background and Aims: The large global population of patients with metabolic dysfunction-associated steatotic liver disease (MASLD) has recently been shown to have an association with chronic kidney disease (CKD) due to a host of proposed mechanisms, one of which being lipoprotein dysmetabolism. Furthermore, metabolic comorbidities have been concurrently prevalent in MASLD and CKD independently. This study aimed at analyzing risk and predictive traits among an obese population for both MASLD and CKD. Methods: A retrospective chart review of 546 obese patients with a diagnosis of either MASLD or metabolic dysfunction-associated steatohepatitis between January 2020 and June 2021 was performed. Markers of liver and kidney function in addition to demographic data and renoprotective medications were recorded. Both univariable and multivariable linear regression analyses were performed to understand possible associations between MASLD markers, renal function, and markers of metabolic derangements. Results: Univariate analysis revealed that increased age (P < .001), elevated alanine aminotransferase (defined as alanine aminotransferase ≥ 30 IU/L, P = .01), low albumin (P = .011), and increasing fibrosis-4 (FIB-4) (P = .005) were statistically associated with a reduced renal function. A reduction in glomerular filtration was associated with an increase in FIB-4 (effect size [beta] of a one-unit increase in glomerular filtration on FIB-4 = -0.013, P < .001) in univariate linear regression. In multivariate linear regression, type 2 diabetes (T2D) was independently associated with increased liver fibrosis (effect size of T2D on FIB-4 = 0.387925, P < .02). Conclusion: Our study shows that in a patient population with obesity and a diagnosis of MASLD, advanced fibrosis is independently associated with reduced renal function.
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BACKGROUND AND AIMS: Liver macrophages fulfill various homeostatic functions and represent an essential line of defense against pathogenic insults. However, it remains unclear whether a history of infectious disease in the liver instructs long-term alterations to the liver macrophage compartment. METHODS: We utilized a curable model of parasitic infection invoked by the protozoan parasite Trypanosoma brucei brucei to investigate whether infection history can durably reshape hepatic macrophage identity and function. Employing a combination of fate mapping, single cell CITE-sequencing, single nuclei multiome analysis, epigenomic analysis, and functional assays, we studied the alterations to the liver macrophage compartment during and after the resolution of infection. RESULTS: We show that T. b. brucei infection alters the composition of liver-resident macrophages, leading to the infiltration of monocytes that differentiate into various infection-associated macrophage populations with divergent transcriptomic profiles. Whereas infection-associated macrophages disappear post-resolution of infection, monocyte-derived macrophages engraft in the liver, assume a Kupffer cell (KC)-like profile and co-exist with embryonic KCs in the long-term. Remarkably, the prior exposure to infection imprinted an altered transcriptional program on post-resolution KCs that was underpinned by an epigenetic remodeling of KC chromatin landscapes and a shift in KC ontogeny, along with transcriptional and epigenetic alterations in their niche cells. This reprogramming altered KC functions and was associated with increased resilience to a subsequent bacterial infection. CONCLUSION: Our study demonstrates that a prior exposure to a parasitic infection induces trained immunity in KCs, reshaping their identity and function in the long-term. IMPACT AND IMPLICATIONS: Although the liver is frequently affected during infections, and despite housing a major population of resident macrophages known as Kupffer cells (KCs), it is currently unclear whether infections can durably alter KCs and their niche cells. Our study provides a comprehensive investigation into the long-term impact of a prior, cured parasitic infection, unveiling long-lasting ontogenic, epigenetic, transcriptomic and functional changes to KCs as well as KC niche cells, which may contribute to KC remodeling. Our data suggest that infection history may continuously reprogram KCs throughout life with potential implications for subsequent disease susceptibility in the liver, influencing preventive and therapeutic approaches.
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Background: Dihydroartemisinin (DHA), a derivative of Artemisia annua, has been shown to possess anti-inflammatory properties. Besides, Yes-associated protein 1 (YAP1) plays a crucial role in maintaining liver homeostasis. Methods: This study used Yap1 Flox/Flox, Albumin-Cre mice with hepatocyte-specific Yap1 knockout (referred to as Yap1 LKO) and their control mice (Yap1 Flox/Flox, referred to as Yap1 Flox). The effect of Yap1 on lipid metabolism homeostasis was investigated through non-targeted metabolomic analysis of mouse liver. Subsequently, DHA was administered to Yap1 LKO mice to assess its potential as a treatment. Liver pathology was evaluated via H&E staining, and the levels of AST, ALT, and TG were quantified using biochemical assays. The contents of arachidonic acid (AA), prostaglandin E1 (PGE1), and leukotrienes (LT) in the liver were measured using ELISA, while the protein expressions of PLIN2, 5-lipoxygenase (5-LOX), and cyclooxygenase-2 (COX-2) were analyzed through IHC staining. Results: Hepatocyte-specific Yap1 knockout activated the AA metabolic pathway, resulting in increased elevated levels of AA, PGE1, and LT levels, along with inflammatory cytokine infiltration. DHA mitigated the elevation of metabolites such as PGE1 and LT caused by the AA metabolic pathway activation by down-regulating the levels of COX-2 and 5-LOX in the liver of Yap1 LKO mice. Moreover, it alleviated the accumulation of lipid vacuoles and reduced triglyceride (TG) and perilipin-2 (PLIN2) levels in the liver of Yap1 LKO mice. Conclusions: Excessively low YAP1 expression induces liver inflammation and disturbances in lipid metabolism, whereas DHA modulated AA metabolism and mitigated liver inflammation by inhibiting the activation of 5-LOX and COX-2.
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The chemokine (CCL)-chemokine receptor (CCR2) interaction, importantly CCL2-CCR2, involved in the intrahepatic recruitment of monocytes upon liver injury promotes liver fibrosis. CCL2-CCR2 antagonism using Cenicriviroc (CVC) showed promising results in several preclinical studies. Unfortunately, CVC failed in phase III clinical trials due to lack of efficacy to treat liver fibrosis. Lack of efficacy could be attributed to the fact that macrophages are also involved in disease resolution by secreting matrix metalloproteinases (MMPs) to degrade extracellular matrix (ECM), thereby inhibiting hepatic stellate cells (HSCs) activation. HSCs are the key pathogenic cell types in liver fibrosis that secrete excessive amounts of ECM causing liver stiffening and liver dysfunction. Knowing the detrimental role of intrahepatic monocyte recruitment, ECM, and HSCs activation during liver injury, we hypothesize that combining CVC and MMP (MMP1) could reverse liver fibrosis. We evaluated the effects of CVC, MMP1 and CVC + MMP1 in vitro and in vivo in CCl4-induced liver injury mouse model. We observed that CVC + MMP1 inhibited macrophage migration, and TGF-ß induced collagen-I expression in fibroblasts in vitro. In vivo, MMP1 + CVC significantly inhibited normalized liver weights, and improved liver function without any adverse effects. Moreover, MMP1 + CVC inhibited monocyte infiltration and liver inflammation as confirmed by F4/80 and CD11b staining, and TNFα gene expression. MMP1 + CVC also ameliorated liver fibrogenesis via inhibiting HSCs activation as assessed by collagen-I staining and collagen-I and α-SMA mRNA expression. In conclusion, we demonstrated that a combination therapeutic approach by combining CVC and MMP1 to inhibit intrahepatic monocyte recruitment and increasing collagen degradation respectively ameliorate liver inflammation and fibrosis.
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Matriz Extracelular , Células Estrelladas Hepáticas , Cirrosis Hepática , Metaloproteinasa 1 de la Matriz , Monocitos , Animales , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 1 de la Matriz/genética , Ratones , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Monocitos/metabolismo , Monocitos/efectos de los fármacos , Matriz Extracelular/metabolismo , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Hígado/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Tetracloruro de Carbono , Modelos Animales de Enfermedad , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Humanos , Movimiento Celular/efectos de los fármacos , Sinergismo Farmacológico , Imidazoles , SulfóxidosRESUMEN
Dysregulation of the polyamine metabolism is common in different cancer types. SMOX is upregulated in hepatocellular carcinoma (HCC) but the relationship between SMOX and liver inflammation and fibrosis, remains unclear. In this issue of Clin Res Hepatol Gastroenterol, Hu and colleagues find targeting SMOX can alleviate liver cancer progression.
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Nod-like receptor family pyrin-containing protein 3 (NLRP3) inflammasome plays a pathologic role in metabolic dysfunction-associated steatohepatitis (MASH), but the molecular mechanism regulating the NLRP3 inflammasome activation in hepatocellular lipotoxicity remains largely unknown. Bromodomain-containing protein 4 (BRD4) has emerged as a key epigenetic reader of acetylated lysine residues in enhancer regions that control the transcription of key genes. The aim of this study is to investigate if and how BRD4 regulated the NLRP3 inflammasome activation and pyroptosis in MASH. Using the AML12 and primary mouse hepatocytes stimulated by palmitic acid (PA) as an in vitro model of hepatocellular lipotoxicity, we found that targeting BRD4 by genetic knockdown or a selective BRD4 inhibitor MS417 protected against hepatosteatosis; and this protective effect was attributed to inhibiting the activation of NLRP3 inflammasome and reducing the expression of Caspase-1, gasdermin D (GSDMD), interleukin (IL)-1ß and IL-6. Moreover, BRD4 inhibition limited the voltage-dependent anion channel-1 (VDAC1) expression and oligomerization in PA-treated AML12 hepatocytes, thereby suppressing the NLRP3 inflammasome activation. Additionally, the expression of BRD4 enhanced in MASH livers of humans. Mechanistically, BRD4 was upregulated during hepatocellular lipotoxicity that in turn modulated the active epigenetic mark H3K27ac at the promoter regions of the Vdac and Gsdmd genes, thereby enhancing the expression of VDAC and GSDMD. Altogether, our data provide novel insights into epigenetic mechanisms underlying BRD4 activating the NLRP3 inflammasome and promoting GSDMD-mediated pyroptosis in hepatocellular lipotoxicity. Thus, BRD4 might serve as a novel therapeutic target for the treatment of MASH.
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Hepatocitos , Inflamasomas , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR , Proteínas de Unión a Fosfato , Piroptosis , Factores de Transcripción , Animales , Humanos , Masculino , Ratones , Proteínas que Contienen Bromodominio , Proteínas de Ciclo Celular , Hígado Graso/metabolismo , Hígado Graso/patología , Furanos , Gasderminas , Hepatocitos/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/patología , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Indenos/farmacología , Inflamasomas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteínas Nucleares , Ácido Palmítico/farmacología , Proteínas de Unión a Fosfato/metabolismo , Proteínas de Unión a Fosfato/genética , Piroptosis/efectos de los fármacos , Sulfonamidas/farmacología , Factores de Transcripción/metabolismo , Factores de Transcripción/genéticaRESUMEN
Liver diseases have a global prevalence of 25%, accounting for 4% of all deaths worldwide, and are associated with a 36% increased risk of fatal and nonfatal cardiovascular events. Metabolic dysfunction-associated steatotic liver disease constitutes the liver expression of metabolic syndrome and represents the primary type of liver disease. Microscopical analysis of biopsies, which allows the evaluation of a small portion of tissue with inferences made to the entire organ, is considered the gold standard for determining the presence of liver diseases. However, potential sampling errors in liver biopsies are conceivable because the obtained tissue represents only a tiny fraction of the entire liver mass and may not accurately reflect the true pathological state. Studies have demonstrated the existence of sampling errors in liver biopsies, particularly concerning the severity of inflammation, degree of fibrosis, and the presence of cirrhosis. Also, clinical studies have shown that histopathological abnormalities are better detected in humans when liver samples are collected from both the right and the left lobes. However, a gap exists in clinical investigation to clarify the role of differences between these lobes in improving the diagnostic and prognostic for liver diseases. Building upon the heterogeneous nature of pathological alterations observed in liver lobes, this perspective review provided recommendations to enhance the precision of diagnosis and prognostic accuracy of liver diseases.
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Hepatopatías , Hígado , Humanos , Hígado/patología , Hepatopatías/patología , Hepatopatías/diagnóstico , Hepatopatías/epidemiología , Biopsia , Pronóstico , Síndrome Metabólico/patología , Síndrome Metabólico/epidemiología , Síndrome Metabólico/diagnóstico , Cirrosis Hepática/patología , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/epidemiología , AnimalesRESUMEN
Hepatic stellate cells (HSCs) are responsible for liver fibrosis accompanied by its activation into myofibroblasts and the abundant production of extracellular matrix. However, the HSC contribution to progression of liver inflammation has been less known. We aimed to elucidate the mechanism in HSCs underlying the inflammatory response and the function of tumor necrosis factor α-related protein A20 (TNFAIP3). We established A20 conditional knockout (KO) mice crossing Twist2-Cre and A20 floxed mice. Using these mice, the effect of A20 was analyzed in mouse liver and HSCs. The human HSC line LX-2 was also used to examine the role and underlying molecular mechanism of A20. In this KO model, A20 was deficient in >80% of HSCs. Spontaneous inflammation with mild fibrosis was found in the liver of the mouse model without any exogenous agents, suggesting that A20 in HSCs suppresses chronic hepatitis. Comprehensive RNA sequence analysis revealed that A20-deficient HSCs exhibited an inflammatory phenotype and abnormally expressed chemokines. A20 suppressed JNK pathway activation in HSCs. Loss of A20 function in LX-2 cells also induced excessive chemokine expression, mimicking A20-deficient HSCs. A20 overexpression suppressed chemokine expression in LX-2. In addition, we identified DCLK1 in the genes regulated by A20. DCLK1 activated the JNK pathway and upregulates chemokine expression. DCLK1 inhibition significantly decreased chemokine induction by A20-silencing, suggesting that A20 controlled chemokine expression in HSCs via the DCLK1-JNK pathway. In conclusion, A20 suppresses chemokine induction dependent on the DCLK1-JNK signaling pathway. These findings demonstrate the therapeutic potential of A20 and the DCLK1-JNK pathway for the regulation of inflammation in chronic hepatitis.
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Quimiocinas , Células Estrelladas Hepáticas , Sistema de Señalización de MAP Quinasas , Ratones Noqueados , Proteínas Serina-Treonina Quinasas , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa , Animales , Células Estrelladas Hepáticas/metabolismo , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/metabolismo , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/genética , Ratones , Humanos , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Quimiocinas/metabolismo , Quimiocinas/genética , Hepatitis Crónica/metabolismo , Hepatitis Crónica/patología , Hepatitis Crónica/genética , Quinasas Similares a Doblecortina , Ratones Endogámicos C57BL , Línea Celular , MasculinoRESUMEN
Codonopsis pilosula polysaccharides (CPP), the main active ingredient of Codonopsis pilosula, has gained significant attention as a liver-protective agent. Previous studies have demonstrated that CPP could alleviate gut microbiota dysbiosis in colitis or obese mice. However, the effects of CPP on mycotoxin-induced liver injury and gut microbiota dysbiosis are still poorly understood. In this study, we aimed to investigate the protective effects of CPP on sterigmatocystin (STC)-induced liver injury, as well as its regulatory effects on gut microbiota. Our results revealed that CPP intervention significantly alleviated STC-induced liver injury, as evidenced by decreased liver index, reduced liver histopathological changes, and modulation of related molecular markers. Additionally, we found that CPP could alleviate liver injury by reducing liver inflammation and oxidative stress, inhibiting hepatocyte apoptosis, and regulating lipid metabolism. Notably, we also observed that CPP could alleviate STC-induced gut microbiota dysbiosis by modulating the diversity and richness of gut microbiota, suggesting that gut microbiota modulation may also serve as a mechanism for CPP-mediated remission of liver injury. In summary, our study not only provided a new theoretical basis for understanding the hepatotoxicity of STC and the protective effects of CPP against STC-induced liver injury, but also provided new perspectives for the application of CPP in the fields of food, healthcare products, and medicine.
Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Codonopsis , Disbiosis , Microbioma Gastrointestinal , Polisacáridos , Esterigmatocistina , Microbioma Gastrointestinal/efectos de los fármacos , Animales , Disbiosis/tratamiento farmacológico , Codonopsis/química , Ratones , Polisacáridos/farmacología , Polisacáridos/química , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Masculino , Esterigmatocistina/farmacología , Estrés Oxidativo/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patologíaRESUMEN
ADAR1-mediated RNA editing establishes immune tolerance to endogenous double-stranded RNA (dsRNA) by preventing its sensing, primarily by MDA5. Although deleting Ifih1 (encoding MDA5) rescues embryonic lethality in ADAR1-deficient mice, they still experience early postnatal death, and removing other MDA5 signaling proteins does not yield the same rescue. Here, we show that ablation of MDA5 in a liver-specific Adar knockout (KO) murine model fails to rescue hepatic abnormalities caused by ADAR1 loss. Ifih1;Adar double KO (dKO) hepatocytes accumulate endogenous dsRNAs, leading to aberrant transition to a highly inflammatory state and recruitment of macrophages into dKO livers. Mechanistically, progranulin (PGRN) appears to mediate ADAR1 deficiency-induced liver pathology, promoting interferon signaling and attracting epidermal growth factor receptor (EGFR)+ macrophages into dKO liver, exacerbating hepatic inflammation. Notably, the PGRN-EGFR crosstalk communication and consequent immune responses are significantly repressed in ADAR1high tumors, revealing that pre-neoplastic or neoplastic cells can exploit ADAR1-dependent immune tolerance to facilitate immune evasion.
Asunto(s)
Adenosina Desaminasa , Receptores ErbB , Hepatocitos , Helicasa Inducida por Interferón IFIH1 , Hígado , Macrófagos , Ratones Noqueados , Progranulinas , Animales , Adenosina Desaminasa/metabolismo , Adenosina Desaminasa/genética , Receptores ErbB/metabolismo , Macrófagos/metabolismo , Macrófagos/inmunología , Progranulinas/metabolismo , Progranulinas/genética , Hígado/metabolismo , Hígado/inmunología , Hígado/patología , Hepatocitos/metabolismo , Ratones , Helicasa Inducida por Interferón IFIH1/metabolismo , Helicasa Inducida por Interferón IFIH1/genética , Transducción de Señal , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intercelular/genética , Ratones Endogámicos C57BL , ARN Bicatenario/metabolismo , Edición de ARNRESUMEN
Copper (Cu) serves as an essential cofactor in all organisms, yet excessive Cu exposure is widely recognized for its role in inducing liver inflammation. However, the precise mechanism by which Cu triggers liver inflammation in ducks, particularly in relation to the interplay in gut microbiota regulation, has remained elusive. In this investigation, we sought to elucidate the impact of Cu exposure on liver inflammation through gut-liver axis in ducks. Our findings revealed that Cu exposure markedly elevated liver AST and ALT levels and induced liver inflammation through upregulating pro-inflammatory cytokines (IL-1ß, IL-6 and TNF-α) and triggering the LPS/TLR4/NF-κB signaling pathway. Simultaneously, Cu exposure induced alterations in the composition of intestinal flora communities, notably increasing the relative abundance of Sphingobacterium, Campylobacter, Acinetobacter and reducing the relative abundance of Lactobacillus. Cu exposure significantly decreased the protein expression related to intestinal barrier (Occludin, Claudin-1 and ZO-1) and promoted the secretion of intestinal pro-inflammatory cytokines. Furthermore, correlation analysis was observed that intestinal microbiome and gut barrier induced by Cu were closely related to liver inflammation. Fecal microbiota transplantation (FMT) experiments further demonstrated the microbiota-depleted ducks transplanting fecal samples from Cu-exposed ducks disturbed the intestinal dysfunction, which lead to impaire liver function and activate the liver inflammation. Our study provided insights into the mechanism by which Cu exposure induced liver inflammation in ducks through the regulation of gut-liver axis. These results enhanced our comprehension of the potential mechanisms driving Cu-induced hepatotoxicity in avian species.