RESUMEN
Myosin 1c (Myo1c) is an unconventional myosin that modulates signaling pathways involved in tissue injury and repair. In this study, we observed that Myo1c expression is significantly upregulated in human chronic liver disease such as nonalcoholic steatohepatitis (NASH) and in animal models of liver fibrosis. High throughput data from the GEO-database identified similar Myo1c upregulation in mice and human liver fibrosis. Notably, transforming growth factor-ß1 (TGF-ß1) stimulation to hepatic stellate cells (HSCs), the liver pericyte and key cell type responsible for the deposition of extracellular matrix, upregulates Myo1c expression, whereas genetic depletion or pharmacological inhibition of Myo1c blunted TGF-ß-induced fibrogenic responses, resulting in repression of α-smooth muscle actin (α-SMA) and collagen type I α 1 chain (Col1α1) mRNA. Myo1c deletion also decreased fibrogenic processes such as cell proliferation, wound healing response, and contractility when compared with vehicle-treated HSCs. Importantly, phosphorylation of mothers against decapentaplegic homolog 2 (SMAD2) and mothers against decapentaplegic homolog 3 (SMAD3) were significantly blunted upon Myo1c inhibition in GRX cells as well as Myo1c knockout (Myo1c-KO) mouse embryonic fibroblasts (MEFs) upon TGF-ß stimulation. Using the genetic Myo1c-KO mice, we confirmed that Myo1c is critical for fibrogenesis, as Myo1c-KO mice were resistant to carbon tetrachloride (CCl4)-induced liver fibrosis. Histological and immunostaining analysis of liver sections showed that deposition of collagen fibers and α-SMA expression were significantly reduced in Myo1c-KO mice upon liver injury. Collectively, these results demonstrate that Myo1c mediates hepatic fibrogenesis by modulating TGF-ß signaling and suggest that inhibiting this process may have clinical application in treating liver fibrosis.NEW & NOTEWORTHY The incidences of liver fibrosis are growing at a rapid pace and have become one of the leading causes of end-stage liver disease. Although TGF-ß1 is known to play a prominent role in transforming cells to produce excessive extracellular matrix that lead to hepatic fibrosis, the therapies targeting TGF-ß1 have achieved very limited clinical impact. This study highlights motor protein myosin-1c-mediated mechanisms that serve as novel regulators of TGF-ß1 signaling and fibrosis.
Asunto(s)
Fibroblastos/metabolismo , Cirrosis Hepática/metabolismo , Hígado/metabolismo , Miosina Tipo I/metabolismo , Animales , Cadena alfa 1 del Colágeno Tipo I , Fibroblastos/patología , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Hígado/patología , Cirrosis Hepática/genética , Cirrosis Hepática/patología , Ratones , Miosina Tipo I/genética , Fosforilación , Transducción de Señal/fisiología , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
In recent years, epidemiological studies have consistently demonstrated that the coexistence of nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) is strongly associated with increased mortality and morbidity related to hepatic- and extrahepatic causes. Indeed, compared with the general population, patients with T2DM are more likely to be diagnosed with more severe forms of NAFLD (i.e., nonalcoholic steatohepatitis (NASH) with liver fibrosis). There is an ongoing debate whether NALFD is a consequence of diabetes or whether NAFLD is simply a component and manifestation of the metabolic syndrome, since liver fat (steatosis) and even more advanced stages of liver fibrosis can occur in the absence of diabetes. Nevertheless, insulin resistance is a key component of the mechanism of NAFLD development; furthermore, therapies that lower blood glucose concentrations also appear to be effective in the treatment of NAFLD. Here, we will discuss the pathophysiological and epidemiological associations between NAFLD and T2DM. We will also review currently available anti-diabetic agents with their regard to their efficacy of NAFLD/NASH treatment.
Asunto(s)
Hipoglucemiantes/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , HumanosRESUMEN
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrialized nations and is strongly associated with the metabolic syndrome. The prevalence of NAFLD continues to rise along with the epidemic of the metabolic syndrome. Metabolic homeostasis is linked to the circadian clock (rhythm), with multiple signaling pathways in organs regulated by circadian clock genes, and recent studies of circadian clock gene functions suggest that disruption of the circadian rhythm is associated with significant morbidity and mortality, including the metabolic syndrome. In the industrialized world, various human behaviors and activities such as work and eating patterns, jet lag, and sleep deprivation interfere with the circadian rhythm, leading to perturbations in metabolism and development of the metabolic syndrome. In this review, we discuss how disruption of the circadian rhythm is associated with various metabolic conditions that comprise the metabolic syndrome and NAFLD.
Asunto(s)
Relojes Circadianos/fisiología , Síndrome Metabólico , Enfermedad del Hígado Graso no Alcohólico , Humanos , Estilo de Vida , Síndrome Metabólico/complicaciones , Síndrome Metabólico/fisiopatología , Síndrome Metabólico/psicología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/metabolismoRESUMEN
Hepatocellular carcinoma (HCC) is a common complication of chronic liver diseases and remains a relevant cause of cancer-related mortality worldwide. The global prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) as a risk factor for hepatocarcinogenesis is on the rise. Early detection of HCC has been crucial in improving the survival outcomes of patients with metabolic dysfunction-associated steatohepatitis (MASH), even in the absence of cirrhosis. Understanding how hepatocarcinogenesis develops in MASH is increasingly becoming a current research focus. Additive risk factors such as type 2 diabetes mellitus (T2DM), genetic polymorphisms, and intestinal microbiota may have specific impacts. Pathophysiological and epidemiological associations between MASH and HCC will be discussed in this review. We will additionally review the available tumor therapies concerning their efficacy in MASH-associated HCC treatment.
RESUMEN
Non-alcoholic fatty liver disease (NAFLD) embraces simple steatosis in non-alcoholic fatty liver (NAFL) to advanced non-alcoholic steatohepatitis (NASH) associated with inflammation, fibrosis, and cirrhosis. NAFLD patients often have metabolic syndrome and high risks of cardiovascular and liver-related mortality. Our aim was to clarify which proteins play a role in the progression of NAFL to NASH. The study investigates paraffin-embedded samples of 22 NAFL and 33 NASH patients. To detect potential candidates, samples were analyzed by immunohistochemistry for the proteins involved in innate immune regulation, autophagy, apoptosis, and antioxidant defense: IRF3, RIG-1, SOCS3, pSTAT3, STX17, SGLT2, Ki67, M30, Caspase 3, and pNRF2. The expression of pNRF2 immunopositive nuclei and SOCS3 cytoplasmic staining were higher in NASH than in NAFL (p = 0.001); pNRF2 was associated with elevated fasting glucose levels. SOCS3 immunopositivity correlated positively with RIG1 (r = 0.765; p = 0.001). Further, in NASH bile ducts showed stronger IRF3 immunostaining than in NAFL (p = 0.002); immunopositive RIG1 tissue was higher in NASH than in NAFL (p = 0.01). Our results indicate that pNRF2, SOCS3, IRF3, and RIG1 are involved in hepatic lipid metabolism. We suggest that they may be suitable for further studies to assess their potential as therapeutics.
RESUMEN
BACKGROUND AND AIMS: Radioembolization (RE) has recently demonstrated a non-inferior survival outcome compared to systemic therapy for advanced hepatocellular carcinoma (HCC). Therefore, current guidelines recommend RE for patients with advanced HCC and preserved liver function who are unsuitable for transarterial chemoembolization (TACE) or systemic therapy. However, despite the excellent safety profile of RE, post-therapeutic hepatic decompensation remains a serious complication that is difficult to predicted by standard laboratory liver function parameters or imaging modalities. LiMAx® is a non-invasive test for liver function assessment, measuring the maximum metabolic capacity for 13C-Methacetin by the liver-specific enzyme CYP 450 1A2. Our study investigates the potential of LiMAx® for predicting post-interventional decompensation of liver function. PATIENTS AND METHODS: In total, 50 patients with HCC with or without liver cirrhosis and not amenable to TACE or systemic treatments were included in the study. For patients prospectively enrolled in our study, LiMAx® was carried out one day before RE (baseline) and 28 and 90 days after RE. Established liver function parameters were assessed at baseline, day 28, and day 90 after RE. The relationship between baseline LiMAx® and pre-and post-interventional liver function parameters, as well as the ability of LiMAx® to predict hepatic decompensation, were analyzed. RESULTS: We observed a strong association between baseline LiMAx® and bilirubin, albumin, ALBI grade, and MELD score. Patients presenting with Child-Pugh score B 28 days after RE or with a deterioration in Child-Pugh score by at least one point had a significantly lower baseline LiMAx® compared to those with Child-Pugh score A or with stable Child-Pugh score. The ability of LiMAx® to predict hepatic decompensation after RE was determined using ROC curve analysis and was compared to MELD score and ALBI grade. LiMAx® achieved a substantial AUC of 0.8117, comparable to MELD score and ALBI grade. CONCLUSION: Patients with lower LiMAx® values at baseline have a significantly increased risk for hepatic decompensation after RE, despite being categorized as Child-Pugh A. Therefore, LiMAx® can be used as an additional tool to identify patients at high risk of post-interventional hepatic failure.
RESUMEN
BACKGROUND: Although excess iron induces oxidative stress in the liver, it is unclear whether it directly activates the hepatic stellate cells (HSC). MATERIALS AND METHODS: We evaluated the effects of excess iron on fibrogenesis and transforming growth factor beta (TGF-ß) signaling in murine HSC. Cells were treated with holotransferrin (0.005-5g/L) for 24 hours, with or without the iron chelator deferoxamine (10µM). Gene expressions (α-SMA, Col1-α1, Serpine-1, TGF-ß, Hif1-α, Tfrc and Slc40a1) were analyzed by quantitative real time-polymerase chain reaction, whereas TfR1, ferroportin, ferritin, vimentin, collagen, TGF-ß RII and phospho-Smad2 proteins were evaluated by immunofluorescence, Western blot and enzyme-linked immunosorbent assay. RESULTS: HSC expressed the iron-uptake protein transferrin receptor 1 (TfR1) and the iron-export protein ferroportin. Holotransferrin upregulated TfR1 expression by 1.8-fold (P < 0.03) and ferritin accumulation (iron storage) by 2-fold (P < 0.01), and activated HSC with 2-fold elevations (P < 0.03) in α-SMA messenger RNA and collagen secretion, and a 1.6-fold increase (P < 0.01) in vimentin protein. Moreover, holotransferrin activated the TGF-ß pathway with TGF-ß messenger RNA elevated 1.6-fold (P = 0.05), and protein levels of TGF-ß RII and phospho-Smad2 increased by 1.8-fold (P < 0.01) and 1.6-fold (P < 0.01), respectively. In contrast, iron chelation decreased ferritin levels by 30% (P < 0.03), inhibited collagen secretion by 60% (P < 0.01), repressed fibrogenic genes α-SMA (0.2-fold; P < 0.05) and TGF-ß (0.4-fold; P < 0.01) and reduced levels of TGF-ß RII and phospho-Smad2 proteins. CONCLUSIONS: HSC express iron-transport proteins. Holotransferrin (iron) activates HSC fibrogenesis and the TGF-ß pathway, whereas iron depletion by chelation reverses this, suggesting that this could be a useful adjunct therapy for patients with fibrosis. Further studies in primary human HSC and animal models are necessary to confirm this.