Study on the regulatory effect of liver X receptor in HEK293 cells by six main diterpene esters in Semen Euphorbiae

Background:To study the effects of the main diterpene esters in Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)on the transcriptional activity and protein expression of liver X receptor(LXR).Methods:The effect of the main diterpene ester components in Semen Euphorbiae on the viability of HEK293 cells were studied by MTT assay.The LXR-Luc plasmid vector was transfected into HEK293 cells and treated with Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)for 24 h.The effect of the main diterpene ester components of Semen Euphorbiae on LXR-Luc luciferase activity was investigated by dual luciferase reporter gene system,and the expression of LXRαprotein was detected by Western Blot.Results:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)could significantly reduce the relative luciferase activity(RLU)of LXRα,and the expression level of LXRαprotein was significantly down-regulated.Conclusion:Euphorbia factor L_(1),L_(2),L_(3),L_(7a),L_(7b)and L_(8)can inhibit the expression of LXR protein level,which may be achieved by inhibiting the transcriptional activity of LXR.

3' Noncoding Region Construction of GHR Gene-luciferase Report Vector and Valuation

To analyze miR-139 target sites in 3＇ UTR of GHR gene in dairy cow mammary gland, a GHR 3＇ UTR- luciferase reporter vector was constructed and the effect of miRNA on its activity was evaluated in dairy cow mammary gland epithelial cells （DCMECs）. The miR-139 targeting GHR 3＇ UTR was predicted by Target Scan 5.1 software, 3＇ UTR fragment of GHR was amplified by PCR from RNA of DCMECs. PCR products were cloned into Spe Ⅰ/Hind Ⅱ modified pMIR-Report vector. The luciferase reporter vector and miRNA eukaryotic expression vector were transferred into DCMECs using lipofectamine 2000 transfection reagent. The dualluciferase reporter assay system was used to quantitiate the reporter activity. The results showed that a 107 bp 3＇ UTR fragment of GHR gene was successfully cloned into the pMIR-Report vector, which authenticated by Spe Ⅰ/Hind Ⅲ digestion and DNA sequencing. The luciferase activity of reporter construction treated with miR-139 decreased 20.87% compared with the control group. It was concluded that the GHR3＇ UTR-luciferase reporter vector had been successfully constructed. The luciferase activity of the reporter could be suppressed by miR- 139.

Protective mechanisms of micro RNA-27a against oxygen-glucose deprivation-induced injuries in hippocampal neurons

Hypoxic injuries during fetal distress have been shown to cause reduced expression of micro RNA-27a（mi R-27a）,which regulates sensitivity of cortical neurons to apoptosis.We hypothesized that miR-27 a overexpression attenuates hypoxia- and ischemia-induced neuronal apoptosis by regulating FOXO1,an important transcription factor for regulating the oxidative stress response.miR-27 a mimic was transfected into hippocampal neurons to overexpress miR-27 a.Results showed increased hippocampal neuronal viability and decreased caspase-3 expression.The luciferase reporter gene system demonstrated that mi R-27 a directly binded to FOXO1 3′UTR in hippocampal neurons and inhibited FOXO1 expression,suggesting that FOXO1 was the target gene for mi R-27 a.These findings confirm that mi R-27 a protects hippocampal neurons against oxygen-glucose deprivation-induced injuries.The mechanism might be mediated by modulation of FOXO1 and apoptosis-related gene caspase-3 expression.

Effects of CMV Enhancer on Activity and Specificity of Bovine MyoG Gene Promoter

Connected a segment of CMV enhancer to the front of MyoG gene promoter and then constructed the corresponding dual luciferase expression vector pGL3-CMV-MyoGpro. We set four eukaryotic expression vectors including pGL3-CMV, pGL3MyoGpro, pGL3-CMV-MyoGpro, and pGL3-Basic which contained CMV promoter, MyoG promoter, CMV-MyoG synthesis promoter, and a promoterless negative control, respectively. Then the four vectors and internal control Renilla luciferase report gene vector phRL-TK were transfected into bovine skeletal muscle satellite cells, mouse C2C12 cells and bovine fetal fibroblast cells to detect the promoter activity with dual luciferase report system. The results showed that CMV enhancer could significantly improve the transcription activity of bovine MyoG gene promoter in muscle satellite cells and mouse C2C12 cells, and it had certain specificity. This study provided experimental materials for increasing the high expression of exogenous gene in bovine muscle cells, and also laid the molecular theoretical basis for obtaining the high specific promoter of bovine muscle and the transgenic beef cattle.

MicroRNA-219 alleviates glutamate-induced neurotoxicity in cultured hippocampal neurons by targeting calmodulin-dependent protein kinase Ⅱ gamma

Septic encephalopathy is a frequent complication of sepsis,but there are few studies examining the role of micro RNAs（mi Rs） in its pathogenesis.In this study,a mi R-219 mimic was transfected into rat hippocampal neurons to model mi R-219 overexpression.A protective effect of mi R-219 was observed for glutamate-induced neurotoxicity of rat hippocampal neurons,and an underlying mechanism involving calmodulin-dependent protein kinase II γ（Ca MKIIγ） was demonstrated.mi R-219 and Ca MKIIγ m RNA expression induced by glutamate in hippocampal neurons was determined by quantitative real-time reverse transcription-polymerase chain reaction（q RT-PCR）.After neurons were transfected with mi R-219 mimic,effects on cell viability and apoptosis were measured by 3-（4,5-dimethylthiazolyl-2）-2,5-diphenyltetrazolium bromide（MTT） assay and flow cytometry.In addition,a luciferase reporter gene system was used to confirm Ca MKIIγ as a target gene of mi R-219.Western blot assay and rescue experiments were also utilized to detect Ca MKIIγ expression and further verify that mi R-219 in hippocampal neurons exerted its effect through regulation of Ca MKIIγ.MTT assay and q RT-PCR results revealed obvious decreases in cell viability and mi R-219 expression after glutamate stimulation,while Ca MKIIγ m RNA expression was increased.MTT,flow cytometry,and caspase-3 activity assays showed that mi R-219 overexpression could elevate glutamate-induced cell viability,and reduce cell apoptosis and caspase-3 activity.Moreover,luciferase Ca MKIIγ-reporter activity was remarkably decreased by co-transfection with mi R-219 mimic,and the results of a rescue experiment showed that Ca MKIIγ overexpression could reverse the biological effects of mi R-219.Collectively,these findings verify that mi R-219 expression was decreased in glutamate-induced neurons,Ca MKIIγ was a target gene of mi R-219,and mi R-219 alleviated glutamate-induced neuronal excitotoxicity by negatively controlling Ca MKIIγ expression.

Effect of the C.–1388 A>G polymorphism in chicken heat shock transcription factor 3 gene on heat tolerance

Heat stress is one of the main factors that inlfuence poultry production. Heat shock proteins (HSPs) are known to affect heat tolerance. The formation of HSPs is regulated by heat shock transcription factor 3 (HSF3) in chicken. A DNA pool was established for identifying single nucleotide polymorphisms (SNPs) of the chicken HSF3, and 13 SNPs were detected. The bioinformatic analysis showed that 8 SNPs had the capacity to alter the transcription activity of HSF3. The dual luciferase report gene assay showed that there was a signiifcant difference (P<0.01) in the Firelfy luciferase/Renil a luciferase ratio (F/R) of C.–1 703 A>G (S1) and C.–1 388 A>G (S4) sites at the 5′-untranslated region (UTR) of chicken HSF3. The elec-trophoretic mobility shift assay showed that the S4 site was a transcription binding factor. The analysis of the association of the S1 and S4 sites with heat tolerance index revealed that the S4 site was signiifcantly correlated with the CD3+T cel , corticosterone, and T3 levels in Lingshan chickens and with the heterophil/lymphocyte value in White Recessive Rock. These results showed that the S4 site at the 5′ UTR of chicken HSF3 might have an impact on heat tolerance in summer and could be used as a potential marker for the selection of chicken with heat tolerance in the future.

MEDICINAL PLANTS OF THE GENUS LEONURUS AND SEVENTEEN OF THEIR ISOLATED CONSTITUENTS SCREENED FOR EFFECTS ON PPARa,β/δ, and γ IN AN IN VITRO LUCIFERASE REPORTER GENE ASSAY

Leonurus japonicus Houtt.is used in TCM to treat the metabolic syndrome.However,up to now,no active constituents could be identified.Here we describe the isolation of 17 dominant constituents of L.japonicus and the related European herb Leonurus cardiaca L.-namely7R-chloro-6-desoxy-harpagide,ajugol,campneoside II,chicoric acid,ferulic acid,harpagide,isoacteoside,

Transcriptional upregulation of restin by p53

Restin, belonging to the melanoma-associated antigen superfamily, was firstly cloned from the differentiated HL-60 cells when induced by all-trans retinoic acid ( ATRA ) in our lab. Our previous results showed that restin might be correlated to cell cycle arrest. Due to the importance of p53 in the regulation of cell growth and the relationship between p53 and ATRA, we tried to test the relationship between p53 and restin. Firstly, transfection results showed that p53 was able to upregulate the expression of restin at the transcriptional level when p53 was transfected into eukaryotic cells. Secondly, the bioinformatics analysis revealed that the upstream sequence (about 2 kb) from the first ATG of the ORF of restin gene contained a p53 binding site. In order to confirm that p53 was involved in the transcriptional regulation of restin, we cloned the upstream sequence of restin and constructed the promoter luciferase reporter system. From the luciferase activity, we demonstrated that the promoter of restin gene could be induced by ATRA. Then, another two luciferase reporter plasmids driven by the reporter of restin with no (RP?p53-luc) or mutant (mRP-luc) p53 binding site were constructed to see the regulation of restin by p53. Results showed that the transcriptional upregulation of restin gene was not due to the putative p53 binding site on the upstream of restin gene. We proposed that p53 upregulated restin transcription through an indirect way rather than direct interaction with the cis-activating element of the restin promoter.

Development of A MERS-CoV Replicon Cell Line for Antiviral Screening

Middle East respiratory syndrome coronavirus(MERS-CoV)is the causative agent of a severe respiratory disease with a high mortality of~35%.The lack of approved treatments for MERS-CoV infection underscores the need for a user-friendly system for rapid drug screening.In this study,we constructed a MERS-CoV replicon containing the Renilla luciferase(Rluc)reporter gene and a stable luciferase replicon-carrying cell line.Using this cell line,we showed that MERS-CoV replication was inhibited by combined application of lopinavir and ritonavir,indicating that this cell line can be used to screen inhibitors of MERS-CoV replication.Importantly,the MERS-replicon cell line can be used for high-throughput screening of antiviral drugs without the need for live virus handling,providing an effective and safe tool for the discovery of antiviral drugs against MERS-CoV.

Mapping the transcription repressive domain in the highly conserved human gene hnulp1

HNULP1,a new member of the basic helixloop-helix transcription factors,contains a DUF654 domain in its C-terminus and is highly conserved from Drosophilae,yeast,zebrafish to mouse.The function of this motif,however,is currently unknown.In this research,we fused five deletion fragments of the DUF654 domain to the GAL4 DNA-binding domain and then co-transfected with plasmids L8G5-Luc and VP-16.The analysis of the GAL4 luciferase reporter gene indicated that fragments from 228 to 407 amino acids in the DUF654 domain had a strong transcription repression activity.Therefore,this study lays a solid foundation for research on the mechanism of hnulp1 transcriptional regulation and the function of the DUF654 domain.