A method of qualitative and quantitative analysis on fluid catalytic cracking (FCC) full range gasoline by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOF MS) was established. The results showed that paraffins, olefins, naphthenes and aromatics in FCC gasoline had regional and zonal distribution in two-dimensional contour plots. The distinctions of boiling points and polarity between different compounds were used to achieve the accurate separation and determination in GC×GC-TOF MS analysis, and consequently the co-current flow which was often present in the conventional GC analysis was greatly suppressed. The difference of ionizing efficiency between different compounds was modified by response factors, and moreover, a good quantitative dependency was found between the analysis results of GC and GC×GC-TOF MS on FCC gasoline. Due to the high separation resolution, GC×GC-TOF MS gave more accurate results about the group compositions of FCC gasoline. GC×GC-TOF MS provided an effective way with high precision for the characterization of FCC gasoline.

AIM:To investigate the effect of caspase-8 small hairpin RNA ( shRNA) on attenuating apoptosis of human mesenchymal stem cells ( hMSCs ) .METHODS: Two recombinant plasmids for over-expression of caspase-8 shRNA, pAd-Cap8 shRNA1 and pAd-Cap8 shRNA2, were constructed.Caspase-8 mRNA was determined in pAd-Cap8 shRNA-transfected human HEK293 cells by Q-PCR.The screened pAd-Cap8 shRNA was used to construct the recombinant adenovirus plasmid , which was linearized and transfected into HEK 293 cells for packaging and amplification of the recombi-nant adenovirus rAd-Cap8 shRNA.The expression of caspase-8 at mRNA and protein levels was determined by Q-PCR and Western blotting .Annexin V/PI staining and determination of caspase-8 activity were performed to assess apoptosis of hM-SCs under the conditions of serum deprivation and hypoxia .The mRNA expression of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), insulin-like growth factor 1 (IGF-1), Bcl-2 and Bcl-xL was analyzed by Q-PCR.RESULTS:The pAd-Cap8 shRNA, which efficiently inhibited caspase-8 expression, was screened by Q-PCR.The recombinant adenovirus plasmid for caspase-8 shRNA was constructed and used to package and amplify the recombinant ad-enovirus ( rAd)-Cap8 shRNA successfully .rAd-Cap8 shRNA-mediated caspase-8 shRNA markedly inhibited caspase-8 ex-pression in hMSCs .Over-expression of caspase-8 shRNA by infection of rAd-Cap8 shRNA also efficiently decreased the ap-optotic rate and caspase-8 activity in hMSCs under the conditions of serum deprivation and hypoxia , with up-regulation of the mRNA expression of HGF, IGF-1 and Bcl-2.CONCLUSION:Caspase-8 shRNA attenuates hMSC apoptosis under the conditions of serum deprivation and hypoxia .

AIM:To construct recombinant adenovirus vector carrying human miR-133a and study its expression in human mesenchymal stem cells(hMSCs).METHODS:The PCR product containing miR-133a was amplified from human genomic DNA and inserted into the adenoviral shuttle vector pAdTrack-CMV.Then the recombinant shuttle plasmid linearized by pmeⅠwas cotransformed into competent E.coli.BJ5183 with the adenoviral backbone plasmid pAdEasy-1 to generate the recombinant adenovirus vector rAd-mir-133a.rAd-mir-133a was then packaged and amplified in human embryonic kidney 293(HEK293) cells.The purified rAd-miR-133a was used to infect the hMSCs and the expression of miR-133a was detected by non-quantitative RT-PCR and real-time PCR.RESULTS:The recombinant adenovirus shuttle vector pAdTrack-CMV-miR-133a was constructed and verified by restriction endonuclease analysis and DNA sequence analysis.rAd-miR-133a was successfully packaged and amplified in HEK293 cells.The transcriptions of primary miR-133a and mature miR-133a were over-expressed in the hMSCs infected with rAd-miR-133a.CONCLUSION:The recombinant adenovirus vector carrying human miR-133a is successfully constructed,which lay a foundation for miR-133a function study.

AIM: To establish human umbilical vein endothelial cells (HUVECs) to express green fluorescent protein (GFP), and to study the suppression of GFP by siRNA in HUVECs. METHODS: Using lipofectamine 2000 to transform plasmid pN_3-EGFP encoding GFP into HUVECs. The HUVEC containing pN_3-EGFP, named HUVEC-GFP, was screened and selected by antibiotic G418. Using in vitro transcription T7 kit, GFPsiRNA targeting GFP mRNA and control-siRNA used as control were synthesized. The siRNAs were transfected into HUVEC-GFP with oligofectamine. 48 h later, the expression levels of GFP protein and mRNA in HUVEC-GFP were determined. RESULTS: The HUVEC-GFP was screened to express GFP in the presence of G418. The agarose gel electrophoresis analysis showed that the siRNAs prepared were integrated. 48 h after transfection with siRNAs, compared to control group, the level of GFP fluorescence was obviously decreased in the HUVEC-GFP transfected with GFPsiRNA. The results of RT-PCR detection showed that GFP mRNA expression was obviously suppressed by GFPsiRNA at the rate of 40%, and no obvious suppression of GFP mRNA expression was found in the HUVEC-GFP transfected with control siRNA. CONCLUSION: The siRNA targeting GFP mRNA, synthesized in vitro, efficiently suppresses the GFP expression in HUVECs.

AIM:To investigate the effect of microRNA-214 ( miR-214) on cardiomyocyte hypertrophy and the expression of the potential target genes .METHODS:A cell model of hypertrophy was established based on angiotensin-Ⅱ( Ang-Ⅱ)-induced neonatal mouse ventricular cardiomyocytes ( NMVCs) .Dual luciferase reporter assay was performed to verify the interaction between miR-214 and the 3’ UTR of MEF2C.The expression of MEF2C and hypertrophy-related genes at mRNA and protein levels was determined by RT-qPCR and Western blot , respectively .RESULTS:The expression of ANP, ACTA1,β-MHC and miR-214 was markedly increased in Ang-Ⅱ-induced hypertrophic cardiomyocytes .Dual lu-ciferase reporter assay revealed that miR-214 interacted with the 3’ UTR of MEF2C, and miR-214 was verified to inhibit MEF2C expression at the transcriptional level .The protein expression of MEF2C was markedly increased in the hypertro-phic cardiomyocytes .Moreover, miR-214 mimic, in parallel to MEF2C siRNA, inhibited the expression of hypertrophy-re-lated genes in Ang-Ⅱ-induced NMVCs.CONCLUSION:MEF2C is a target gene of miR-214, which mediates the effect of miR-214 on attenuating cardiomyocyte hypertrophy .