GW4064, a farnesoid X receptor agonist, upregulates adipokine expression in preadipocytes and HepG2 cells

AIM:To investigate the effect of GW4064 on the expression of adipokines and their receptors during differentiation of 3T3-L1 preadipocytes and in HepG2cells.METHODS:The mRNA expression of farnesoid X receptor(FXR),peroxisome proliferator-activated receptor-gamma 2(PPAR-γ2),adiponectin,leptin,resistin,adiponectin receptor 1(AdipoR1),adiponectin receptor2(AdipoR2),and the long isoform of leptin receptor(OB-Rb)and protein levels of adiponectin,leptin,andresistin were determined using fluorescent real-time PCR and enzyme linked immunosorbent assay,respectively,on days 0,2,4,6,and 8 during the differentiation of 3T3-L1 preadipocytes exposed to GW4064.Moreover,mRNA expression of AdipoR2 and OB-Rb was also examined using fluorescent real-time PCR at 0,12,24,and 48 h in HepG2 cells treated with GW4064.RESULTS:The mRNA expression of FXR,PPAR-γ2,adiponectin,leptin,resistin,AdipoR1,AdipoR2,and OB-Rb and protein levels of adiponectin,leptin,and resistin increased along with differentiation of 3T3-L1preadipocytes(P<0.05 for all).The mRNA expression of FXR,PPAR-γ2,adiponectin,leptin,and AdipoR2in 3T3-L1 preadipocytes,and AdipoR2 and OB-Rb in HepG2 cells was significantly increased after treatment with GW4064,when compared with the control group(P<0.05 for all).A similar trend was observed for protein levels of adipokines(including adiponectin,leptin and resistin).However,the expression of resistin,AdipoR1,and OB-Rb in 3T3-L1 cells did not change after treatment with GW4064.CONCLUSION:The FXR agonist through regulating,at least partially,the expression of adipokines and their receptors could offer an innovative way for counteracting the progress of metabolic diseases such as nonalcoholic fatty liver disease.

Combination of small interfering RNAs mediates greater suppression on hepatitis B virus cccDNA in HepG2.2.15 cells

AIM: To observe the inhibition of hepatitis B virus (HBV) replication and expression in HepG2.2.15 cells by combination of small interfering RNAs (siRNAs). METHODS: Recombinant plasmid psil-HBV was constructed and transfected into HepG2.2.15 cells. At 48 h,72 h and 96 h after transfection,culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay (ELISA). Intracellular viral DNA and covalently closed circular DNA (cccDNA) were quantifi ed by real-time polymerase chain reaction (PCR). HBV viral mRNA was reverse transcribed and quantifi ed by reverse-transcript PCR (RT-PCR). RESULTS: siRNAs showed marked anti-HBV effects. siRNAs could specifically inhibit the expression of HBsAg and the replication of HBV DNA in a dose-dependent manner. Furthermore,combination of siRNAs,compared with individual use of each siRNA,exerted a stronger inhibition on antigen expression and viral replication. More importantly,combination of siRNAs significantly suppressed HBV cccDNA amplifi cation. CONCLUSION: Combination of siRNAs mediates a stronger inhibition on viral replication and antigenexpression in HepG2.2.15 cells,especially on cccDNA amplifi cation.