RESUMEN
Epigallocatechin-3-gallate (EGCG) plays a crucial role in hepatic lipid metabolism. However, the underlying regulatory mechanism of hepatic lipid metabolism by EGCG in canine is unclear. Primary canine hepatocytes were treated with EGCG (0.01, 0.1, or 1 µM) and BML-275 (an AMP-activated protein kinase [AMPK] inhibitor) to study the effects of EGCG on the gene and protein expressions associated with AMPK signaling pathway. Data showed that treatment with EGCG had greater activation of AMPK, as well as greater expression levels and transcriptional activity of peroxisome proliferator activated receptor-α (PPARα) along with upregulated messenger RNA (mRNA) abundance and protein abundance of PPARα-target genes. EGCG decreased the expression levels and transcriptional activity of sterol regulatory element-binding protein 1c (SREBP-1c) along with downregulated mRNA abundance and protein abundance of SREBP-1c target genes. Of particular interest, exogenous BML-275 could reduce or eliminate the effects of EGCG on lipid metabolism in canine hepatocytes. Furthermore, the content of triglyceride was significantly decreased in the EGCG-treated groups. These results suggest that EGCG might be a potential agent in preventing high-fat diet-induced lipid accumulation in small animals.
Asunto(s)
Proteínas Quinasas Activadas por AMP/genética , Catequina/análogos & derivados , Hepatocitos/metabolismo , Metabolismo de los Lípidos/genética , Transducción de Señal/genética , Animales , Catequina/genética , Células Cultivadas , Dieta Alta en Grasa , Perros , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Hepatocitos/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , PPAR alfa/genética , Pirazoles/farmacología , Pirimidinas/farmacología , Transducción de Señal/efectos de los fármacos , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Transcripción Genética/efectos de los fármacos , Transcripción Genética/genética , Triglicéridos/genética , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genéticaRESUMEN
The current study aimed at investigating the effects of flavonoids from Astragalus complanatus (FAC) on the proliferation, the contents, and gene expression levels of cytokines, secretion of surface stimulating factors, cell cycle, and the expression level of the NF-κB signalling pathway in RAW264.7 cells. Our results revealed that compared with control group, the contents of IL-6, IL-1ß, TNF-α, and NO and the mRNA expression levels of IL-6, IL-1ß, TNF-α, and iNOS in FAC-treated groups significantly increased (p < 0.01). Moreover, FAC induced macrophage activation to release the above-mentioned mediators partly involved in NF-κB/MAPK signalling pathways. Therefore, FAC regulates immune function in RAW264.7 cells via activating the NF-κB signalling pathway. FAC could be applicable for agriculture, drug research, and food industry as a potent immune-modulatory agent.
Asunto(s)
Antiinflamatorios/farmacología , Flavonoides/farmacología , Macrófagos/inmunología , Animales , Planta del Astrágalo/inmunología , Ciclo Celular , Proliferación Celular , Citocinas/genética , Citocinas/metabolismo , Regulación de la Expresión Génica , Inmunomodulación , Mediadores de Inflamación/metabolismo , Ratones , FN-kappa B/metabolismo , Células RAW 264.7 , Transducción de SeñalRESUMEN
The present study was designed to investigate the effects of Astragaloside IV (ASIV) on the immune functions of RAW264.7 cells. Compared with control group, the concentrations of interleukin 1ß (IL-1ß), tumor necrosis factor α (TNF-α) and nitric oxide (NO) were higher in the 100µg/mL ASIV-treatment group. The interleukin 6 (IL-6) concentration was significantly higher in the 50 and 100µg/mL ASIV-treatment groups. The relative mRNA expression levels of IL-1ß, TNF-α and inducible nitric oxide synthase (iNOS) were significantly higher in the 50 and 100µg/mL ASIV-treatment groups. The relative mRNA expression levels of IL-6 in the 100µg/mL ASIV-treatment group were significantly higher. In contrast, the relative mRNA expression levels of interleukin 4 (IL-4) and IL-6 markedly reduced in ASIV-treatment groups. Furthermore, ASIV promoted the secretion of CD40 and CD86 and increased the number of cells in G2/M phase. The apoptosis of RAW264.7 cells was decreased in ASIV-treatment groups. The protein levels of cyclin D1, CDK4 and CDK6, p50 and p-p65 increased in a dose-dependent manner. The ratio of p50/ß-actin was significantly higher in the 50 and 100µg/mL ASIV-treatment groups, and p-p65/p65 was significantly higher in the 25, 50 and 100µg/mL ASIV-treatment groups. The phosphorylation levels of p38, ERK and JNK increased, and the protein expression of total p38, ERK and JNK decreased in a dose-dependent manner. These effects of ASIV were alleviated by PDTC. ASIV enhances the immune function of RAW264.7 cells by activating the NF-κB/MAPK signaling pathway.