The purpose of this study was to examine the induction profiles （as judged by quantitative reverse tran- scription polymerase chain reaction （qRT-PCR）） of peroxisome proliferator-activated receptor （PPAR） α,β,...The purpose of this study was to examine the induction profiles （as judged by quantitative reverse tran- scription polymerase chain reaction （qRT-PCR）） of peroxisome proliferator-activated receptor （PPAR） α,β, y subtypes and major PPAR-target genes bearing a functional peroxisome proliferator responsive element （PPRE） in HepG2 cell model upon feeding with cis-9,trans-11-octadecadienoic acid （9-CLA） or trans-10,cis-12-octadecadienoic acid （10-CLA） or their precursor fatty acids （FAs）. HepG2 cells were treated with 100 pmol/L 9-CLA or 10-CLA or their precursor FAs, viz., oleic, linoleic, and trans-11-vaccenic acids against bezafibrate control to evaluate the induc- tion/expression profiles of PPAR （α, β, γ subtypes and major PPAR-target genes bearing a functional PPRE, i.e., fatty acid transporter （FAT）, glucose transporter-2 （GLUT-2）, liver-type FA binding protein （L-FABP）, acyl CoA oxidase-1 （ACOX-1）, and peroxisomal bifunctional enzyme （PBE） with reference to β-actin as house keeping gene. Of the three housekeeping genes （glyceraldehyde 3-phosphate dehydrogenase （GAPDH）, β-actin, and ubiquitin）, β-actin was found to be stable. Dimethyl sulfoxide （DMSO）, the common solubilizer of agonists, showed a significantly higher induction of genes analyzed, qRT-PCR profiles of CLAs and their precursor FAs clearly showed upregulation of FAT, GLUT-2, and L-FABP （-0.5-.0-fold）. Compared to 10-CLA, 9-CLA decreased the induction of the FA metabolizing gene ACOX-1 less than did PBE, while 10-CLA decreased the induction of PBE less than did ACOX-I. Both CLAs and precursor FAs upregulated PPRE-beadng genes, but with comparatively less or marginal activation of PPAR subtypes This indicates that the binding of CLAs and their precursor FAs to PPAR subtypes results in PPAR activation, thereby induction of the target transporter genes coupled with downstream lipid metabolising genes such as ACOX-1 and PBE. To sum up, the expression profiles of these candidate genes showed that CLAs and their precursor FAs are involved in lipid signalling by modulating the PPAR a, 13, or ~ subtype for the indirect activation of the PPAR-target genes, which may in turn be responsible for the supposed health effects of CLA, and that care should be taken while calculating the actual fold induction values of candidate genes with reference to housekeeping gene and DMSO as they may impart false positive results.展开更多
目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXR...目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXRα)表达的关系。方法用鹅去氧胆酸(chenodeoxycholic ac id,CDCA)或苯巴比妥(phenobarb ital,PB)分别刺激培养的肝癌细胞HepG2并建立DBL阻塞性胆汁淤积大鼠模型后,分别抽提HepG2细胞总蛋白、核蛋白和大鼠肝脏细胞膜蛋白和核蛋白,W estern b lot方法检测MRP3和RXRα蛋白表达水平的变化。结果在细胞水平,CDCA和PB可诱导HepG2细胞膜MRP3蛋白表达增高,并抑制细胞核RXRα蛋白表达;在动物体内,BDL大鼠肝脏MRP3明显增加,同时RXRα表达明显下降。结论肝细胞膜蛋白MRP3表达的上调可能与核受体RXRα表达抑制有关。展开更多
基金Project (No. SP 135/14-1) supported by the Deutsche Forschungs-gemeinschaft,Germany
文摘The purpose of this study was to examine the induction profiles （as judged by quantitative reverse tran- scription polymerase chain reaction （qRT-PCR）） of peroxisome proliferator-activated receptor （PPAR） α,β, y subtypes and major PPAR-target genes bearing a functional peroxisome proliferator responsive element （PPRE） in HepG2 cell model upon feeding with cis-9,trans-11-octadecadienoic acid （9-CLA） or trans-10,cis-12-octadecadienoic acid （10-CLA） or their precursor fatty acids （FAs）. HepG2 cells were treated with 100 pmol/L 9-CLA or 10-CLA or their precursor FAs, viz., oleic, linoleic, and trans-11-vaccenic acids against bezafibrate control to evaluate the induc- tion/expression profiles of PPAR （α, β, γ subtypes and major PPAR-target genes bearing a functional PPRE, i.e., fatty acid transporter （FAT）, glucose transporter-2 （GLUT-2）, liver-type FA binding protein （L-FABP）, acyl CoA oxidase-1 （ACOX-1）, and peroxisomal bifunctional enzyme （PBE） with reference to β-actin as house keeping gene. Of the three housekeeping genes （glyceraldehyde 3-phosphate dehydrogenase （GAPDH）, β-actin, and ubiquitin）, β-actin was found to be stable. Dimethyl sulfoxide （DMSO）, the common solubilizer of agonists, showed a significantly higher induction of genes analyzed, qRT-PCR profiles of CLAs and their precursor FAs clearly showed upregulation of FAT, GLUT-2, and L-FABP （-0.5-.0-fold）. Compared to 10-CLA, 9-CLA decreased the induction of the FA metabolizing gene ACOX-1 less than did PBE, while 10-CLA decreased the induction of PBE less than did ACOX-I. Both CLAs and precursor FAs upregulated PPRE-beadng genes, but with comparatively less or marginal activation of PPAR subtypes This indicates that the binding of CLAs and their precursor FAs to PPAR subtypes results in PPAR activation, thereby induction of the target transporter genes coupled with downstream lipid metabolising genes such as ACOX-1 and PBE. To sum up, the expression profiles of these candidate genes showed that CLAs and their precursor FAs are involved in lipid signalling by modulating the PPAR a, 13, or ~ subtype for the indirect activation of the PPAR-target genes, which may in turn be responsible for the supposed health effects of CLA, and that care should be taken while calculating the actual fold induction values of candidate genes with reference to housekeeping gene and DMSO as they may impart false positive results.
文摘目的通过体外细胞培养和建立大鼠胆管结扎(b ile duct ligation,BDL)所致阻塞性胆汁淤积动物模型,在蛋白水平观察多耐药相关蛋白MRP3(mu ltidrug resistance-assoc iated prote in 3,MRP3)和核受体RXRα(retinoid-X receptor al-pha,RXRα)表达的关系。方法用鹅去氧胆酸(chenodeoxycholic ac id,CDCA)或苯巴比妥(phenobarb ital,PB)分别刺激培养的肝癌细胞HepG2并建立DBL阻塞性胆汁淤积大鼠模型后,分别抽提HepG2细胞总蛋白、核蛋白和大鼠肝脏细胞膜蛋白和核蛋白,W estern b lot方法检测MRP3和RXRα蛋白表达水平的变化。结果在细胞水平,CDCA和PB可诱导HepG2细胞膜MRP3蛋白表达增高,并抑制细胞核RXRα蛋白表达;在动物体内,BDL大鼠肝脏MRP3明显增加,同时RXRα表达明显下降。结论肝细胞膜蛋白MRP3表达的上调可能与核受体RXRα表达抑制有关。
