AIM:Interferon α2b (IFNα2b) and thymosin α1 (Tα1) exhibit synergic effects in the treatment of hepatitis B and hepatitis C when used together. For developing a fusion protein drug, fusion proteins of IFNα2b and T...AIM:Interferon α2b (IFNα2b) and thymosin α1 (Tα1) exhibit synergic effects in the treatment of hepatitis B and hepatitis C when used together. For developing a fusion protein drug, fusion proteins of IFNα2b and Ta1 linked by different lengths of (G4S)n(n = 1-3) were constructed and expressed in Pichia pastoris. METHODS: Using PCR and molecular clone techniques, the fusion genes of IFNα2b-(G4S)n-Tα1 (n = 1-3) were constructed and subcloned into the eukaryotic expression vector pPIC9. After transformation of these plasmids into P. pastoris, the expressed fusion proteins IFNα2b-(G4S) n-Tα1 (n = 1-3) were obtained. These proteins were purified through diethylaminoethyl (DEAE) affinity chromatography and Superdex?75 gel filtration and analyzed by SDS-PAGE and Western blot. Antiviral and E-rosette assays were used to investigate the bioactivities of these fusion proteins. RESULTS: DNA sequencing confirmed that the fusion genes of IFNa2b-(G4S)n-Tα1 (n= 1-3) were correctly cloned to the pPIC9 vector. The recombinant IFNα2b-(G4S)n-Tα1 (n = 1-3) fusion proteins expressed in P. pastoris were purified with DEAE and Superdex?75 gel filtration chromatography. The fusion proteins could be observed on sodium dodecylsulfate-polyacrylamide gel electrophoresis with molecular weight (MW) of 23.2, 22.9, and 22.6 ku, respectively, and reacted to the IFNa2b monoclonal antibody and Tal polyclonal antibody. The purified fusion proteins exhibit antiviral activity and can enhance the percentage of E-rosette-forming-cell in E-rosette assay. CONCLUSION: The recombinant IFNa2b-(G4S)n-Tα1 (n = 1-3) fusion proteins were successfully expressed in P. pastoris. Purified fusion proteins exhibit both antiviral activity of IFNa2b and immunomodulatory activity of Tal in vitro. These results will be the basis for further evaluation of the fusion proteins' function in vivo.展开更多
To achieve higher level expression of Interferon α2b(IFN-α2b)in methylotrophic yeast(Pichia pastoris),a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of...To achieve higher level expression of Interferon α2b(IFN-α2b)in methylotrophic yeast(Pichia pastoris),a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P.pastoris and optimized G+C content.The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA,and then integrated into P.pastoris GS115 genome by electroporation.Multi-copy integrants in the Mut+ recombinant P.pastoris strain were screened by high concentrations of Zeocin.120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods.In addition,Western blot analysis showed that the recombinant proteins had immunogenicity.The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/VSV system,which was 3.3×105 IU/mL.展开更多
目的探讨环状RNA ACAP2(circACAP2)调节微小RNA(miR)-421/B细胞易位基因2(BTG2)轴对心肌梗死(MI)大鼠心肌损伤的影响。方法构建MI大鼠模型和H9c2细胞模型,将80只大鼠分为假手术组、MI组、小干扰RNA-阴性对照(si-NC)组、si-circACAP2组、...目的探讨环状RNA ACAP2(circACAP2)调节微小RNA(miR)-421/B细胞易位基因2(BTG2)轴对心肌梗死(MI)大鼠心肌损伤的影响。方法构建MI大鼠模型和H9c2细胞模型,将80只大鼠分为假手术组、MI组、小干扰RNA-阴性对照(si-NC)组、si-circACAP2组、pcDNA3.1组、pcDNA3.1-circACAP2组、pcDNA3.1-circACAP2+模拟物(mimic)NC组、pcDNA3.1-circACAP2+miR-421 mimic组,每组各10只。将缺氧H9c2细胞置于24孔板中,瞬时转染细胞,分为缺氧组、缺氧+si-NC组、缺氧+si-circACAP2组、缺氧+pcDNA3.1组、缺氧+pcDNA3.1-circACAP2组、缺氧+pcDNA3.1-circACAP2+mimic NC组、缺氧+pcDNA3.1-circACAP2+miR-421 mimic组,另取正常培养的H9c2细胞作为对照组。检测大鼠左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)、心肌梗死情况、心肌组织病理变化、circACAP2、miR-421、BTG2 mRNA表达情况、乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)活性、H9c2细胞活力和凋亡、心肌组织BTG2蛋白表达、H9c2细胞BTG2蛋白表达。结果MI组circACAP2、BTG2 mRNA表达高于假手术组(1.84±0.21 vs 1.00±0.10,1.68±0.17 vs 1.00±0.10),miR-421表达低于假手术组(0.49±0.05 vs 1.00±0.11,P<0.05);与假手术组比较,MI组梗死面积、CK-MB、LDH活性升高,LVFS、LVEF降低(P<0.05)。与si-NC组比较,si-circACAP2组心肌损伤减轻,LVFS、LVEF升高,梗死面积、CK-MB、LDH活性降低(P<0.05);与缺氧+si-NC组比较,缺氧+si-circACAP2组细胞活力升高,凋亡率、CK-MB和LDH活性降低(P<0.05)。与pcDNA3.1组比较,pcDNA3.1-circACAP2组心肌损伤加重,LVFS、LVEF降低,梗死面积、CK-MB、LDH活性升高(P<0.05);与缺氧+pcDNA3.1组比较,缺氧+pcDNA3.1-circACAP2组细胞活力降低,凋亡率、CK-MB、LDH活性升高(P<0.05)。结论circACAP2在MI大鼠和H9c2细胞中表达上调,沉默circACAP2可能通过调节miR-421/BTG2轴改善心脏功能,减少心肌损伤,提高心肌细胞活力。展开更多
文摘AIM:Interferon α2b (IFNα2b) and thymosin α1 (Tα1) exhibit synergic effects in the treatment of hepatitis B and hepatitis C when used together. For developing a fusion protein drug, fusion proteins of IFNα2b and Ta1 linked by different lengths of (G4S)n(n = 1-3) were constructed and expressed in Pichia pastoris. METHODS: Using PCR and molecular clone techniques, the fusion genes of IFNα2b-(G4S)n-Tα1 (n = 1-3) were constructed and subcloned into the eukaryotic expression vector pPIC9. After transformation of these plasmids into P. pastoris, the expressed fusion proteins IFNα2b-(G4S) n-Tα1 (n = 1-3) were obtained. These proteins were purified through diethylaminoethyl (DEAE) affinity chromatography and Superdex?75 gel filtration and analyzed by SDS-PAGE and Western blot. Antiviral and E-rosette assays were used to investigate the bioactivities of these fusion proteins. RESULTS: DNA sequencing confirmed that the fusion genes of IFNa2b-(G4S)n-Tα1 (n= 1-3) were correctly cloned to the pPIC9 vector. The recombinant IFNα2b-(G4S)n-Tα1 (n = 1-3) fusion proteins expressed in P. pastoris were purified with DEAE and Superdex?75 gel filtration chromatography. The fusion proteins could be observed on sodium dodecylsulfate-polyacrylamide gel electrophoresis with molecular weight (MW) of 23.2, 22.9, and 22.6 ku, respectively, and reacted to the IFNa2b monoclonal antibody and Tal polyclonal antibody. The purified fusion proteins exhibit antiviral activity and can enhance the percentage of E-rosette-forming-cell in E-rosette assay. CONCLUSION: The recombinant IFNa2b-(G4S)n-Tα1 (n = 1-3) fusion proteins were successfully expressed in P. pastoris. Purified fusion proteins exhibit both antiviral activity of IFNa2b and immunomodulatory activity of Tal in vitro. These results will be the basis for further evaluation of the fusion proteins' function in vivo.
基金The National ‘973’ Basic Research Program (2002CB111302) The National Natural Science Foundation of China (30370807)
文摘To achieve higher level expression of Interferon α2b(IFN-α2b)in methylotrophic yeast(Pichia pastoris),a cDNA fragment coding for the mature IFN-α2b was designed and synthesized based on the synonymous codon bias of P.pastoris and optimized G+C content.The synthetic IFN-α2b was inserted into the secreted expression vector pPICZαA,and then integrated into P.pastoris GS115 genome by electroporation.Multi-copy integrants in the Mut+ recombinant P.pastoris strain were screened by high concentrations of Zeocin.120 hours culturing allowed expression of the IFN-α2b transformant up to 810 mg/L as detected by SDS-PAGE and quantitative methods.In addition,Western blot analysis showed that the recombinant proteins had immunogenicity.The significant antiviral activity of the recombinant IFN-α2b protein was verified by WISH/VSV system,which was 3.3×105 IU/mL.
文摘目的探讨环状RNA ACAP2(circACAP2)调节微小RNA(miR)-421/B细胞易位基因2(BTG2)轴对心肌梗死(MI)大鼠心肌损伤的影响。方法构建MI大鼠模型和H9c2细胞模型,将80只大鼠分为假手术组、MI组、小干扰RNA-阴性对照(si-NC)组、si-circACAP2组、pcDNA3.1组、pcDNA3.1-circACAP2组、pcDNA3.1-circACAP2+模拟物(mimic)NC组、pcDNA3.1-circACAP2+miR-421 mimic组,每组各10只。将缺氧H9c2细胞置于24孔板中,瞬时转染细胞,分为缺氧组、缺氧+si-NC组、缺氧+si-circACAP2组、缺氧+pcDNA3.1组、缺氧+pcDNA3.1-circACAP2组、缺氧+pcDNA3.1-circACAP2+mimic NC组、缺氧+pcDNA3.1-circACAP2+miR-421 mimic组,另取正常培养的H9c2细胞作为对照组。检测大鼠左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)、心肌梗死情况、心肌组织病理变化、circACAP2、miR-421、BTG2 mRNA表达情况、乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK-MB)活性、H9c2细胞活力和凋亡、心肌组织BTG2蛋白表达、H9c2细胞BTG2蛋白表达。结果MI组circACAP2、BTG2 mRNA表达高于假手术组(1.84±0.21 vs 1.00±0.10,1.68±0.17 vs 1.00±0.10),miR-421表达低于假手术组(0.49±0.05 vs 1.00±0.11,P<0.05);与假手术组比较,MI组梗死面积、CK-MB、LDH活性升高,LVFS、LVEF降低(P<0.05)。与si-NC组比较,si-circACAP2组心肌损伤减轻,LVFS、LVEF升高,梗死面积、CK-MB、LDH活性降低(P<0.05);与缺氧+si-NC组比较,缺氧+si-circACAP2组细胞活力升高,凋亡率、CK-MB和LDH活性降低(P<0.05)。与pcDNA3.1组比较,pcDNA3.1-circACAP2组心肌损伤加重,LVFS、LVEF降低,梗死面积、CK-MB、LDH活性升高(P<0.05);与缺氧+pcDNA3.1组比较,缺氧+pcDNA3.1-circACAP2组细胞活力降低,凋亡率、CK-MB、LDH活性升高(P<0.05)。结论circACAP2在MI大鼠和H9c2细胞中表达上调,沉默circACAP2可能通过调节miR-421/BTG2轴改善心脏功能,减少心肌损伤,提高心肌细胞活力。
