The molecular mechanism of fibroblast growth factor 21-inhibited leptin expression in adipocytes / 生理学报

The present study was aimed to clarify the signaling molecular mechanism by which fibroblast growth factor 21 (FGF21) regulates leptin gene expression in adipocytes. Differentiated 3T3-F442A adipocytes were used as study object. The mRNA expression level of leptin was detected by fluorescence quantitative RT-PCR. The phosphorylation levels of proteins of signal transduction pathways were detected by Western blot. The results showed that FGF21 significantly down-regulated the mRNA expression level of leptin in adipocytes, and FGF21 receptor inhibitor BGJ-398 could completely block this effect. FGF21 up-regulated the phosphorylation levels of ERK1/2 and AMPK in adipocytes. Either ERK1/2 inhibitor SCH772984 or AMPK inhibitor Compound C could partially block the inhibitory effect of FGF21, and the combined application of these two inhibitors completely blocked the effect of FGF21. Neither PI3K inhibitor LY294002 nor Akt inhibitor AZD5363 affected the inhibitory effect of FGF21 on leptin gene expression. These results suggest that FGF21 may inhibit leptin gene expression by activating ERK1/2 and AMPK signaling pathways in adipocytes.

Facilitative glucose transporters: expression, distribution and the relationship to diseases / 生理学报

Facilitative glucose transporters (GLUT) are proteins that mediate glucose transmembrane transport in the form of facilitated diffusion, which play an important role in regulating cell energy metabolism. There are many breakthroughs in researches of facilitative GLUT in recent years. It has been known that there are 14 subtypes of facilitative GLUT with obvious tissue specificity in distribution and physiological function. In the present review, the tissue and cellular distribution, subcellular localization, expression regulation, physiological function and the relationship to diseases of facilitative GLUT subtypes were summarized, in order to further understand their physiological and pathophysiological significances.

Enterovirus 71 inhibited interferon signaling by downregulating expression of IRF9 / 中国免疫学杂志

Objective:To explore the mechanism of EV71 antagonizing IFN signaling pathway.Methods: RD cells were infected or un-infected with EV71.Then the cells were treated with or without IFN-β.The four groups (the control group,the EV71 group,the IFN-β group,the EV71+IFN-β group) were detected by molecular biology techniques.The expression of interferon stimulated genes (ISGs) were detected by Real-time PCR,while the protein levels of STAT1 and IRF9 were examined by Western blot assay.By preparing the cytosolic and nuclear fractions,the translocation of p-STAT1 was monitored through Western blot assay.Results:Compared with the IFN-β group,the mRNA level of OAS1,MX1 and ISG54 in the EV71+IFN-β group was down regulated by 47%, 50% and 48%,respectively,indicating that EV71 inhibited the expression of ISGs.The results also showed that EV71 did not effect the protein level and phosphorylation of STAT1.Moreover,we found that p-STAT1 was translocated into neuclear in IFN-β group,while p-STAT1 was located in the cytoplasm in the EV71+IFN-β group.And the expression of IRF9 was boviously down regulated in EV71+IFN-β group compared with that in IFN-β group,suggesting that EV71 blocked the expression of IRF9 induced by IFN-β.Conclusion:EV71 inhibited the IFN signaling pathway by downregulating the expression of IRF9 induced by IFN-β.

Expression of HPV16 L1 protein in insect cell suspension culture system / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To express the L1 protein of human papillomavirus type 16 (HPV16) in insect cell suspension culture system.</p><p><b>METHODS</b>Optimized the conditions of suspension culture, recombinant virus amplification and protein expression. Determined the virus tilter by plague analysis and detected the target protein by SDS-PAGE and Western blot; The formation of VLPs by HPV16 L1 protein was observed with TEM.</p><p><b>RESULTS</b>The Sf9 cells could grow better in suspension culture with seeding density of 5 x 10-5 cell/mL and the maximum expression quantity was obtained by infection of cells with rBacV/HPV16L1 (MOI =10) and harvesting after 72-84 h. HPV16L1 protein could assemble into VLPs in Sf9 cells observed with TEM.</p><p><b>CONCLUSION</b>The conditions of cell culture, virus amplification and protein expression were optimized. HPV16 L1 protein could assemble into VLPs in Sf9 cells, which would provide a foundation for further study of the vaccine and diagnosis kits.</p>