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BACKGROUND: Hepatic stellate cell (HSC) hyperactivation is a central link in liver fibrosis development. HSCs perform aerobic glycolysis to provide energy for their activation. Focal adhesion kinase (FAK) promotes aerobic glycolysis in cancer cells or fibroblasts, while FAK-related non-kinase (FRNK) inhibits FAK phosphorylation and biological functions. AIM: To elucidate the effect of FRNK on liver fibrosis at the level of aerobic glycolytic metabolism in HSCs. METHODS: Mouse liver fibrosis models were established by administering CCl4, and the effect of FRNK on the degree of liver fibrosis in the model was evaluated. Transforming growth factor-ß1 was used to activate LX-2 cells. Tyrosine phosphorylation at position 397 (pY397-FAK) was detected to identify activated FAK, and the expression of the glycolysis-related proteins monocarboxylate transporter 1 (MCT-1) and enolase1 (ENO1) was assessed. Bioinformatics analysis was performed to predict putative binding sites for c-myc in the ENO1 promoter region, which were validated with chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. RESULTS: The pY397-FAK level was increased in human fibrotic liver tissue. FRNK knockout promoted liver fibrosis in mouse models. It also increased the activation, migration, proliferation and aerobic glycolysis of primary hepatic stellate cells (pHSCs) but inhibited pHSC apoptosis. Nevertheless, opposite trends for these phenomena were observed after exogenous FRNK treatment in LX-2 cells. Mechanistically, the FAK/Ras/c-myc/ENO1 pathway promoted aerobic glycolysis, which was inhibited by exogenous FRNK. CONCLUSION: FRNK inhibits aerobic glycolysis in HSCs by inhibiting the FAK/Ras/c-myc/ENO1 pathway, thereby improving liver fibrosis. FRNK might be a potential target for liver fibrosis treatment.
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Células Estrelladas Hepáticas , Cirrosis Hepática , Animales , Adhesión Celular , Células Cultivadas , Quinasa 1 de Adhesión Focal , Proteína-Tirosina Quinasas de Adhesión Focal , Glucólisis , Células Estrelladas Hepáticas/metabolismo , Ratones , Fosfopiruvato Hidratasa , Proteínas Proto-Oncogénicas c-myc , Proteínas rasRESUMEN
BACKGROUND: Hepatic stellate cells (HSCs) are the key effector cells mediating the occurrence and development of liver fibrosis, while aerobic glycolysis is an important metabolic characteristic of HSC activation. Transforming growth factor-ß1 (TGF-ß1) induces aerobic glycolysis and is a driving factor for metabolic reprogramming. The occurrence of glycolysis depends on a high glucose uptake level. Glucose transporter 1 (GLUT1) is the most widely distributed glucose transporter in the body and mainly participates in the regulation of carbohydrate metabolism, thus affecting cell proliferation and growth. However, little is known about the relationship between TGF-ß1 and GLUT1 in the process of liver fibrosis and the molecular mechanism underlying the promotion of aerobic glycolysis in HSCs. AIM: To investigate the mechanisms of action of GLUT1, TGF-ß1 and aerobic glycolysis in the process of HSC activation during liver fibrosis. METHODS: Immunohistochemical staining and immunofluorescence assays were used to examine GLUT1 expression in fibrotic liver tissue. A Seahorse extracellular flux (XF) analyzer was used to examine changes in aerobic glycolytic flux, lactate production levels and glucose consumption levels in HSCs upon TGF-ß1 stimulation. The mechanism by which TGF-ß1 induces GLUT1 protein expression in HSCs was further explored by inhibiting/promoting the TGF-ß1/mothers-against-decapentaplegic-homolog 2/3 (Smad2/3) signaling pathway and inhibiting the p38 and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. In addition, GLUT1 expression was silenced to observe changes in the growth and proliferation of HSCs. Finally, a GLUT1 inhibitor was used to verify the in vivo effects of GLUT1 on a mouse model of liver fibrosis. RESULTS: GLUT1 protein expression was increased in both mouse and human fibrotic liver tissues. In addition, immunofluorescence staining revealed colocalization of GLUT1 and alpha-smooth muscle actin proteins, indicating that GLUT1 expression was related to the development of liver fibrosis. TGF-ß1 caused an increase in aerobic glycolysis in HSCs and induced GLUT1 expression in HSCs by activating the Smad, p38 MAPK and P13K/AKT signaling pathways. The p38 MAPK and Smad pathways synergistically affected the induction of GLUT1 expression. GLUT1 inhibition eliminated the effect of TGF-ß1 on HSC proliferation and migration. A GLUT1 inhibitor was administered in a mouse model of liver fibrosis, and GLUT1 inhibition reduced the degree of liver inflammation and liver fibrosis. CONCLUSION: TGF-ß1 induces GLUT1 expression in HSCs, a process related to liver fibrosis progression. In vitro experiments revealed that TGF-ß1-induced GLUT1 expression might be one of the mechanisms mediating the metabolic reprogramming of HSCs. In addition, in vivo experiments also indicated that the GLUT1 protein promotes the occurrence and development of liver fibrosis.
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Transportador de Glucosa de Tipo 1/metabolismo , Células Estrelladas Hepáticas , Factor de Crecimiento Transformador beta1/metabolismo , Animales , Glucólisis , Células Estrelladas Hepáticas/metabolismo , Cirrosis Hepática/patología , Ratones , Fosfatidilinositol 3-Quinasas , Proteínas Smad/metabolismoRESUMEN
BACKGROUND: Massive hepatocyte death is the core event in acute liver failure (ALF). Gasdermin D (GSDMD)-mediated pyroptosis is a type of highly inflammatory cell death. However, the role of hepatocyte pyroptosis and its mechanisms of expanding inflammatory responses in ALF are unclear. AIM: To investigate the role and mechanisms of GSDMD-mediated hepatocyte pyroptosis through in vitro and in vivo experiments. METHODS: The expression of pyroptosis pathway-associated proteins in liver tissues from ALF patients and a hepatocyte injury model was examined by Western blot. GSDMD short hairpin RNA (shRNA) was used to investigate the effects of downregulation of GSDMD on monocyte chemotactic protein 1 (MCP1) and its receptor CC chemokine receptor-2 (CCR2) in vitro. For in vivo experiments, we used GSDMD knockout mice to investigate the role and mechanism of GSDMD in a D-galactose/lipopolysaccharide (D-Galn/LPS)-induced ALF mouse model. RESULTS: The levels of pyroptosis pathway-associated proteins in liver tissue from ALF patients and a hepatocyte injury model increased significantly. The level of GSDMD-N protein increased most obviously (P < 0.001). In vitro, downregulation of GSDMD by shRNA decreased the cell inhibition rate and the levels of MCP1/CCR2 proteins (P < 0.01). In vivo, GSDMD knockout dramatically eliminated inflammatory damage in the liver and improved the survival of D-Galn/LPS-induced ALF mice (P < 0.001). Unlike the mechanism of immune cell pyroptosis that involves releasing interleukin (IL)-1ß and IL-18, GSDMD-mediated hepatocyte pyroptosis recruited macrophages via MCP1/CCR2 to aggravate hepatocyte death. However, this pathological process was inhibited after knocking down GSDMD. CONCLUSION: GSDMD-mediated hepatocyte pyroptosis plays an important role in the pathogenesis of ALF, recruiting macrophages to release inflammatory mediators by upregulating MCP1/CCR2 and leading to expansion of the inflammatory responses. GSDMD knockout can reduce hepatocyte death and inflammatory responses, thus alleviating ALF.
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Hepatocitos/patología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Fallo Hepático Agudo/inmunología , Macrófagos/inmunología , Proteínas de Unión a Fosfato/metabolismo , Piroptosis/inmunología , Animales , Línea Celular , Quimiocina CCL2/metabolismo , Modelos Animales de Enfermedad , Técnicas de Silenciamiento del Gen , Hepatocitos/inmunología , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Fallo Hepático Agudo/inducido químicamente , Fallo Hepático Agudo/patología , Masculino , Ratones , Ratones Noqueados , Proteínas de Unión a Fosfato/genética , ARN Interferente Pequeño/metabolismo , Receptores CCR2/metabolismo , Transducción de Señal/inmunología , Regulación hacia ArribaRESUMEN
OBJECTIVES: To explore the mechanism of interlukin-22 (IL-22)-mediated phosphor-Janus kinase-1(p-JAK1)/phosphor-signal transducer and activator of transcription 3 (p-STAT3) signaling way in the experiment of improving non-alcholic fatty liver disease (NAFLD) by blueberry probiotic serum. METHODS: The rat serums with low-, medium-, and high-dose of 10% blueberry probiotics, as well as saline were prepared. NAFLD model was built by inducing normal liver cell line L-02 with free fatty acid (FFA).NAFLD model cells were cultured with saline serum (model group), low-, medium-, and high-dose blueberry probiotics serums (low-, medium-, and high-dose serum groups) , respectively .Normal liver cell group (normal group) was cultured with saline serum . Oil Red O staining was used to detect the lipid deposition in the cells; the intracellular level of triglyceride (TG) was quantitatively determined; the gene and protein expressions of IL-22, p-JAK1, p-STAT3, sterol-regulatory element binding protein-1c (SREBP-1c ) were detected by RT-PCR, Western blot and immunofluorescence methods. RESULTS: Twenty-four hours after modeling, a large amount of lipid deposition could be observed in model group. Compared with normal group, model group showed lower gene and protein expression levels of IL-22, p-JAK1 and p-STAT3 (P <0.01), and higher SREBP-1c and TG levels (P <0.01).Compared with model group, TG level and the lipid deposition in low-, medium-, and high-dose blueberry probiotics serum groups were gradually reduced. High-dose serum group showed higher gene and protein expression levels of IL-22, p-JAK1, p-STAT3 and lower SREBP-1c compared with the model, low-, and medium-dose serum groups (P <0.01). No significant [CM(155.3mm]differences in gene and protein levels between low- andmedium-doseserum groups were found (P >0.05). CONCLUSION: The blueberry probiotics could antagonize the NAFLD via p-JAK1/p-STAT3 signaling way.
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Arándanos Azules (Planta)/química , Janus Quinasa 1/metabolismo , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Probióticos , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Interleucinas/metabolismo , Ratas , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Interleucina-22RESUMEN
AIM: To observe the effect of Danshao Huaxian capsule (DHC) on the expression of Gremlin and bone morphogenetic protein-7 (BMP-7) in the liver of hepatic fibrosis rats. METHODS: A total of 75 male Wistar rats were randomly divided into a normal control group (A), a CCl4-induced hepatic fibrosis model group (B), a natural recovery group (C), a low-dose DHC-treated group (D), and a high-dose DHC-treated group (E), with 15 rats in each group. Liver fibrosis was induced by subcutaneous injections of carbon tetrachloride (CCl4) and a high-lipid/low-protein diet for 8 wk, except for the rats in group A. Then, the rats in the two DHC-treated groups were administered 0.5 and 1.0 g/kg DHC by gastrogavage once per day for 8 successive weeks, respectively. By the end of the experiment, the level of transforming growth factor ß1 (TGF-ß1) in the liver homogenate was determined by an enzyme-linked immunosorbent assay. The mRNA and protein expression of Gremlin and BMP-7 in the liver tissue was determined by reverse-transcription polymerase chain reaction, an immunohistochemical assay, and Western blot analysis. RESULTS: Compared with group A, the level of TGF-ß1 and the mRNA and protein expression of Gremlin were significantly higher in group B (TGF-ß1: 736.30 ± 24.40 µg/g vs 284.20 ± 18.32 µg/g, P < 0.01; mRNA of Gremlin: 80.40 ± 5.46 vs 49.83 ± 4.20, P < 0.01; positive protein expression rate of Gremlin: 38.46% ± 1.70% vs 3.83% ± 0.88%, P < 0.01; relative protein expression of Gremlin: 2.81 ± 0.24 vs 0.24 ± 0.06, P < 0.01), and the mRNA and protein expression of BMP-7 was significantly lower in group B (mRNA: 54.00 ± 4.34 vs 93.99 ± 7.03, P < 0.01; positive protein expression rate: 28.97% ± 3.14% vs 58.29% ± 6.02, P < 0.01; relative protein expression: 0.48 ± 0.31 vs 1.05 ± 0.12, P < 0.01). Compared with groups B and C, the degree of hepatic fibrosis was significantly improved, and the level of TGF-ß1 and the mRNA and protein expression of Gremlin were significantly lowered in the two DHC-treated groups (TGF-ß1: 523.14 ± 21.29 µg/g, 441.86 ± 23.18 µg/g vs 736.30 ± 24.40 µg/g, 651.13 ± 15.75 µg/g, P < 0.01; mRNA of Gremlin: 64.86 ± 2.83, 55.82 ± 5.39 vs 80.40 ± 5.46, 70.37 ± 4.01, P < 0.01; positive protein expression rate of Gremlin: 20.78% ± 1.60%, 17.43% ± 2.02% vs 38.46% ± 1.70%, 29.50% ± 2.64%, P < 0.01; relative protein expression of Gremlin: 1.95 ± 0.26, 1.65 ± 0.20 vs 2.81 ± 0.24, 2.22 ± 0.63, P < 0.01), and the mRNA and protein expression of BMP-7 was higher in the two DHC-treated groups (mRNA: 73.52 ± 4.56, 81.78 ± 5.38 vs 54.00 ± 4.34, 62.28 ± 4.51, P < 0.01; positive protein expression rate: 41.44% ± 4.77%, 47.49% ± 4.59% vs 28.97% ± 3.14%, 35.85% ± 3.50%, P < 0.01; relative protein expression: 0.71 ± 0.06, 0.81 ± 0.07 vs 0.48 ± 0.31, 0.60 ± 0.37, P < 0.01). CONCLUSION: The therapeutic mechanism of DHC for hepatic fibrosis in rats may be associated with inhibition of the expression of Gremlin and up-regulation of the expression of BMP-7.
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Proteína Morfogenética Ósea 7/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Medicamentos Herbarios Chinos/farmacología , Cirrosis Hepática Experimental/tratamiento farmacológico , Hígado/efectos de los fármacos , Proteínas/metabolismo , Animales , Proteína Morfogenética Ósea 7/genética , Tetracloruro de Carbono , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Citocinas , Regulación de la Expresión Génica , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática Experimental/inducido químicamente , Cirrosis Hepática Experimental/diagnóstico , Cirrosis Hepática Experimental/genética , Cirrosis Hepática Experimental/metabolismo , Masculino , Proteínas/genética , ARN Mensajero/metabolismo , Ratas Wistar , Índice de Severidad de la Enfermedad , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
BACKGROUND: Conventional drugs used in the treatment and prevention of liver diseases often have side effects, therefore research into natural substances are of significance. This study examined the effects of blueberry on liver protection and cellular immune functions. METHODS: To determine the effects of blueberry on liver protective function, male mice were orally administered blueberry (0.6 g/10 g) or normal saline for 21 days. Hepatic RNA was extracted by Trizol reagent, and the expression of Nrf2, HO-1, and Nqo1 was determined by real-time RT-PCR. Superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenate were determined, and liver index was measured. To assess the effects of blueberry on cellular immune function, male mice received blueberry (0.4, 0.6, or 0.8 g/10 g) for 35 days, and the percentages of CD3+, CD4+, and CD8+ T lymphocyte subgroups in peripheral blood were detected by flow cytometry, the index of the thymus and spleen was measured, and lymphocyte proliferation in the spleen was determined by MTT assay. RESULTS: Blueberry treatment significantly increased the expression of Nrf2, HO-1, and Nqo1, the important antioxidant components in the liver. Hepatic SOD in the blueberry group was higher and MDA was lower than that in the control group (P<0.05). Blueberry also increased the index of the spleen and enhanced the proliferation of lymphocytes of the spleen (P<0.05). The percentages of the CD3+ and CD4+ T lymphocyte subsets and the CD4+/CD8+ ratio were also increased by blueberry (P<0.05). CONCLUSIONS: Blueberry induces expression of Nrf2, HO-1, and Nqo1, which can protect hepatocytes from oxidative stress. In addition, blueberry can modulate T-cell function in mice.
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Arándanos Azules (Planta) , Hígado/metabolismo , Linfocitos T/inmunología , Animales , Hemo-Oxigenasa 1/genética , Activación de Linfocitos , Masculino , Ratones , NAD(P)H Deshidrogenasa (Quinona)/genética , Factor 2 Relacionado con NF-E2/genética , ARN Mensajero/análisisRESUMEN
Effects of tannic acid (TA) on the phase transition behaviors of monodisperse poly(N-isopropylacrylamide) (PNIPAM) microgels in aqueous solutions are systematically investigated. Monodisperse PNIPAM microgels are prepared through a microfluidic approach. The isothermal phase transition behaviors of PNIPAM microgels induced by TA in aqueous solutions are studied at 25 degrees C. The results show that there exist significant isothermal phase transition phenomena for PNIPAM microgels induced by TA, and the dynamic phase transition rate and the equilibrium shrinking degree of PNIPAM microgels in TA solutions are dependent on the TA concentration. The higher the TA concentration, the faster the isothermal shrinking rate of PNIPAM microgels induced by TA. There exists a critical TA concentration for the isothermal phase transition behavior, below which the equilibrium shrinking degree of PNIPAM microgels becomes larger with increasing the TA concentration, while above which the equilibrium shrinking degrees of PNIPAM microgels remain almost the same. The adsorption of TA molecules to PNIPAM polymer networks leads to slight shift of the low critical solution temperature to higher temperatures when the TA concentration in solution is lower than 10(-5) mol/L.
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The flow characteristics of monodisperse thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) microspheres during the phase transition in microchannels with different surface wettabilities and roughnesses are investigated systematically. Glass microchannels are modified by hydroxylation treatment to achieve hydrophilic surface, by self-assembly of chlorotrimethylsilane to realize hydrophobic surface, and by coating with silica nanoparticles to generate rough surface. The phase transition of PNIPAM microspheres in microchannels is induced by local heating. The results show that the surface wettability and roughness of microchannel significantly affect the flow behaviors of PNIPAM microspheres during the phase transition. It is much easier for the PNIPAM microspheres in microchannel with hydrophobic surface to stop right after the phase transition than those in microchannel with hydrophilic surface, and it is also much easier for the PNIPAM microspheres in microchannel with rough surface to stop right after the phase transition than those in microchannel with smooth surface. These results indicate that hydrophobic and rough surface properties of the microchannel can enhance the site-specific targeting of PNIPAM microspheres caused by the phase transition. The results in this study provide valuable information for the application of thermo-responsive drug carriers in site-specific targeting therapy.
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Acrilamidas/química , Vidrio/química , Microfluídica , Microesferas , Polímeros/química , Resinas Acrílicas , Transición de Fase , Propiedades de Superficie , Temperatura , HumectabilidadRESUMEN
A novel polymeric lead(II) adsorbent is prepared by incorporating benzo-18-crown-6-acrylamide (BCAm) as metal ion receptor into the thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) hydrogel. Both stimuli-sensitive properties and the Pb(2+)-adsorption capabilities of the prepared P(NIPAM-co-BCAm) hydrogels are investigated. The prepared P(NIPAM-co-BCAm) hydrogels exhibit good ion-recognition and Pb(2+)-adsorption characteristics. When crown ether units capture Pb(2+) and form BCAm/Pb(2+) host-guest complexes, the lower critical solution temperature (LCST) of the hydrogel shifts to a higher temperature due to both the repulsion among charged BCAm/Pb(2+) groups and the osmotic pressure within the hydrogel. The adsorption results at different temperatures show that P(NIPAM-co-BCAm) hydrogels adsorb Pb(2+) ions at temperature lower than the LCST, but undergo desorption at temperature higher than the LCST due to the "stretch-to-shrink" configuration change of copolymer networks which is triggered by the change in environmental temperature. This kind of ion-recognition hydrogel is promising as a novel adsorption material for adsorption and separation of Pb(2+) ions. The adsorption and desorption of Pb(2+) could be rationally achieved by simply changing the environmental temperature.