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AIM: To investigate the protective effect of ferulic acid on palmitic acid-induced lipotoxicity in HepG2 cells and to explore its potential molecular mechanisms. METHODS: HepG2 cells were induced by palmitic acid to establish a lipotoxicity model, while ferulic acid was added prior to palmitic acid treatment. Lactate dehydrogenase (LDH) was used to detect cell damage. Methyl azozole trace enzyme reaction is used for 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) was employed to detect cell viability. The molecular mechanisms of the protective effect of ferulic acid was analyzed by Western Blotting. RESULTS: There was no cytotoxic effect of different concentrations of ferulic acid (25, 50, 100, 200 μmol/L) treatment on HepG2 cells (P>0.05). Ferulic acid intervention significantly inhibited palmitic acid-induced cell death and improved palmitic acid-induced reduction of cell mitochondrial membrane potential (P<0.05). The activation of p38 significantly enhanced palmitic acid-induced hepatocellular lipotoxicity (P<0.05), while inhibition of p38 significantly improved palmitic acid-induced cell damage (P<0.05). In addition, ferulic acid significantly inhibited the upregulation of p38 phosphorylation by palmitic acid treatment (P<0.05). p38 activator exposure blocked the protective effect of ferulic acid on lipotoxicity (P<0.05). CONCLUSION: Ferulic acid effectively improves hepatocellular injury induced by lipotoxicity.The inhibition of p38 signaling pathway is potentially involved in its protective effect. Ferulic acid may be an effective factor in the prevention and treatment of liver disease with lipotoxicity as a major pathological characteristic.
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AIM: To reveal the ameliorative effect of salvianolic acid A on palmitie acid-induced lipotoxicity in H9C2 cells and to explore its potential molecular mechanisms preliminarily. METHODS: H9C2 cell were induced by palmitie acid to establish a lipotoxicity model, while salvianolic acid A was added prior to palmitie acid treatment. Lactate dehydrogenase (LDH) was employed to detect cell damage. Cell counting Kit-8 was used to detect cell viability. The changes of mitochondrial membrane potential in cardiomyocyte were observed by rhodamine 123 staining. The molecular mechanisms of the ameliorative effect of salvianolic acid A was analyzed by Western Blotting. RESULTS: Palmitie acid at a concentration of 400 μmol/L significantly caused lipotoxicity damage to H9C2 cells (P0.05). Salvianolic acid A intervention significantly improved lipotoxicity-induced cell death and reduction of cell mitochondrial membrane potential (P<0.05). The activation of toll-like receptor 4 (TLR4) significantly enhanced lipotoxicity-induced cell damage (P<0.05), while inhibition of TLR4 significantly reduced palmitie acid-induced lipotoxicity (P<0.05). In addition, salvianolic acid A effectively inhibited the upregulation of TLR4 and the downstream c-Jun N-terminal kinase (JNK MAPK) of TLR4 by palmitie acid treatment (P<0.05). CONCLUSION: Salvianolic acid A effectively improves lipotoxicity-induced cardiomyocyte damage. The inhibition of p38 signaling pathway is potentially involved in its protective effect. The protective effect may be related to the inhibition of TLR4/JNK MAPK signaling pathway, providing a potential molecular target for the prevention and treatment of lipotoxic cardiomyopathy.
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AIM: To investigate the protective affect of salvianolic acid A on palmitic acid-induced lipotoxicity in hepatocyte and its potential molecular mechanism. METHODS: The lipotoxicity model of AML12 hepatocytes induced by PA was established. Different concentrations of Sal A (20, 40, 80, 120 μmol/L) were intervened. The hepatocyte injury was detected by the Lactate dehydrogenase (LDH) method, the intracellular triglyceride (TG) content was detected by enzyme assay and the lipid droplets were observed by Bodipy staining, cell viability was detected by MTT, Intracellular reactive oxygen species (ROS) were detected by 2'eci'- dichlorofluorescein diacetate (DCFH-DA) and fluorescence microscope. Mitochondrial membrane potential was detected by rhodamine 123 and fluorescence microscope. The expression of phosphorylation of AMP-activated protein kinase (AMPK) protein and silent information regulator 1 (SIRT1) protein were observed by Western blot. RESULTS: Model of hepatocyte lipotoxicity was established after intervented for 12 h in vitro with PA (0.5 mmol/L). Different concentrations of Sal A could significantly reduce the lipid deposition and hepatocytes injury induced by PA (P<0.05), and the protective effect was dose-dependent. Secondly, Sal A could significantly improve cell mitochondrial membrane potential (P<0.01) and abate the ROS level of hepatocytes induced by PA (P<0.01). In addition, PA could significantly inhibit AMPK and SIRT1 protein expression (P<0.05). Salvianolic acid A can significantly up-regulate SIRT1 and AMPK protein expression (P<0.05). CONCLUSION: Sal A improves PA induced lipotoxicity in hepatocyte, AMPK and SIRT1 may be a potential molecular target.
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Objective To investigatethe role of NF-κB played in the process of the cord blood monocytes differentiating into dendritic cells(DCs)induced by astragalus polysaccharide(APS)and to explore the signal transduction pathway involved in this process.Methods Umbilica]cord blood was collected in aseptic conditions.The cord blood monocytes were obtained by density gradient centrifugation and were divided into three groups afterwards.In the control group.cells were cultivated in the RPMI 1640 complete medium.In the APS group.cells were cultivated in the RPMI 1640 complete medium containing 100 mg/L APS.In the PDTC group:cells were treated with 10 μmol/L disulfide carbamate(PDTC).NF-κB inhibitor in 30 min followed by cultivalion in the RPMI 1640 complete medium containing 100 mg/L APS.,The morphological changes were observed during the process of cultivation by the optical microscope and transmission electron microscopy.Cells were collected 12 d later and the cellular immunophenotyping was assayed by FCM.,The activation and migration of NF-κB fluorescence in the cells was examined by the immunoflouresce microscopy.Results (1)Cells in the control group grown up without cluster forformation and were found fusiform and macrophage-like in 12 d.Cells in the APS group grown up in clnstem,and morphological changes were found from the circular shape to a typical dendritic cells-like shape.Cells in the inhibitor group grown up slowly and without cluster formation,and cell morphdogy had no significant change.(2)The expression of DCs-specific antigen CD80,CD83 and CD86 in the APS group was higher than that in the control group and inhibitom group(P0.05).(3)NF-κB fluorescence in the nuclei was examined by the immunoflourescence microscopy and was much higher in the APS group than that in khe other groups,especially in 72 h with the activation rate of NF-κB (75.20±7.37)%,while(13.20±3.46)% of PDTC group and(8.20 ±1.92)%,respectively(P<0.01).Conclusion Astragalus polysaccharide can induce the differentiation of umbilical cord blood cells into DCs,and NF-κB is the key component of the signal transduction pathway involved in this process.
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Objectives To elucidate the effect of APS replacing cytokine on inducing the cord blood monocyte in vitro into the dendritic cells (DCs) and its cellar immunological characteristic. Methods The cord blood monocytes were isolated and obtained by lymphocyte isolation. three groups were divided: ②Cultured in the RPMI-1640 culture with GM-CSF/IL-4/TNF-?,as the positive control group, with APS in concentration (100mg/L) as the experimental group,and without GM-CSF/IL-4/ TNF-?and APS,as the negative control group, respectively. The morphotype of DCs was identified by inverted optical microscope or scanning electron microscope. The phenotype of cultured 12 days DCs (CD1a, CD80, CD86, and CD83) was identified by flowcytometry. Results Cultured for 72 hours , the morphous of cell of the experimental group grew clustering and began to change from round to irregularity, appearing rough cell face and barb pustute. The longer cell cultured, the more obvious the dendritic structure is. The experimental group cell cultured for 12 days had the most typical dendritic structure. the negative control group cell had no dendritic structure and became the macrophage when cultured for 12 days. The experimental group cell cultured for 10 days showed typical dendritic morphotype by SEM. The experiment group cell and the positive group cell cultured for 12 days significantly expressed the high level phenotype of DCs((CD1a, CD80, CD86, and CD83))by flowcytometry. Conclusions APS and cytokine both could induce the cord blood monocyte to direofive differentiate into functional DC.
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Aim To investigate the lipid-lowering mechanism of Chinese Medicine curcumin.A sterol regulatory report system of LDLR gene expression in HEK-293 cell line was established.Method A green fluorescent protein(GFP) gene was constructed downstream of the sterol regulatory element-1(SRE-1) and the constructed plasmid was introduced into HEK-293 cell line.This SRE-GFP transfected 293 cells were treated with different concentration of curcumin for 2 days.The expression of GFP in the cells was measured by a fluorescence microscope and Flow Cytometry.Results The expression of GFP in SRE-GFP transfected 293 cells was obviously induced by curcumin.Conclusion Curcumin may positively affect the expression of LDLR gene by its influence on SRE-1.
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Objective:To observe the effect of Astragalus polysaccharides(APS) on inducing the cord blood monocytes into mature dendritic cells(DCs) in vitro and to investigate their morphous,cellar immunological characteristics,and contribution to T cell proliferation.Methods:①The cord blood monocytes were isolated by lymphocyte isolating solution under axenic condition,and three groups were divided.②Cells cultured with APS in concentration of 100 mg/L as the experiment group, that with the cytokines of GM-CSF/IL-4/TNF-? as the positive control, and another without either GM-CSF/IL-4/TNF-? or APS as the negative control, respectively. The morphology of DCs was identified by inverted optical microscope or scanning electron microscope. The phenotype of 12 days cultures of DCs(CD1a, CD80, CD86 and CD83) were identified by flowcytometry. The DCs preparations from the experiment group were treated with mitomycin for 45 min to remove their proliferative activity as incentive cells in the mixed cultures with allogenic peripheral blood mononuclear cells from healthy volunteers as responders. T cell proliferation induced with the DCs preparations was detected by MTT chromatometry.Results:After cultured for 72 hours, the cell of both the experiment group and the positive control grew dusteringly and began to change from round to irregularin shapes. The longer the cells were cultured, the more obvious the dendritic structure is. The cells of experiment group and the positive control group when cultured for 12 days had the most typical dendritic structure. The negative control group cells had no dendritic structure and became macrophages when cultured for 12 days. The experiment group cells cultured for 10 days showed typical dendritic morphology by SEM. The experiment group cells and the positive group cells cultured for 12 days significantly expressed high level of the phenotypes of DCs(CD1a, CD80, CD86 and CD83) by flowcytometry.And the difference exhibitied statistical significance when compared with the negative control group(P0.05).The mixed lymphocyte reaction showed that the DCs induced by APS trigerred proliferation of allogenic T cells obviously.Conclusion:Both APS and cytokine could induce the cord blood monocytes to differentiate into functional DCs committedly. DCs reduced by APS stimualate proliferation of the allogenic T cells obviously.