杂色鲍原代细胞培养方法的优化及其在基因功能研究中的应用

优化了杂色鲍原代细胞的培养条件,并利用原代细胞进行了RNAi和外源基因表达。结果表明,较高的渗透压对血淋巴细胞培养起重要作用,淋巴细胞分离液分离血淋巴细胞更利于其生长。原代细胞培养至第5天,在细胞培养液中添加50μg My D88 dsRNA,能够显著降低My D88 mRNA的表达。p EGFP-N1转染培养5 d的鳃细胞,5 d后可以检测到绿色荧光。该研究表明可以成功培养杂色鲍血和鳃原代细胞,并且利用原代细胞可以进行功能基因表达量调低或调研究,为功能基因注释提供了便利条件。     

人胰岛素原基因转染绵羊成纤维细胞及细胞株的建立

从动物耳皮肤组织采样 ,采用将组织块剪碎后直接贴附于培养瓶底部的方法进行原代培养 ,该方法使原代细胞出现率及可传代率均达到 10 0 %。根据上皮样细胞和成纤维样细胞贴壁紧实程度的不同 ,用 0 .0 5 %的胰蛋白酶-EDTA对其进行消化 ,可将两种不同类型的细胞进行分离和纯化。通过脂质体介导 ,以BLG -hINS(含乳球蛋白调控基因的人胰岛素原基因 )基因作为目的基因、GFP(绿色荧光蛋白 )基因作为标记基因共转染绵羊成纤维细胞 ,经G - 4 18筛选后 ,得到转染细胞。对转染的细胞分别用单细胞显微操作法和有限稀释法进行细胞克隆 ,两种方法均可得到克隆细胞。选形态正常、生长均匀的 5个细胞克隆进行PCR检测 ,结果 5个克隆均转有GFP基因 ,其中两个转有BLG -hINS基因。高代培养细胞、转染细胞和克隆细胞经核型分析后 ,染色体数目均为 2 7对 ,表明绵羊耳的成纤维细胞建立细胞株后 ,可以作为外源基因转染的有效供体细胞。     

鸡贫血病毒山东分离株全基因克隆

设计了 Ｃ Ａ５、 Ｃ Ａ６ 和 Ｃ Ａ７、 Ｃ Ａ８ 两对引物,分别扩增鸡贫血病毒（ Ｃ Ａ Ｖ）山东分离株 Ｓ Ｊ１ 的 １５ Ｋｂ 和 ０８ Ｋｂ Ｄ Ｎ Ａ 片段。并将这两个片段分别克隆至 ｐ Ｕ Ｃ１１９ 和ｐ Ｂｌｕｅｓｃｒｉｐｔ（ Ｓ Ｋ＋ ）载体质粒,最后一起克隆到 ｐ Ｑ Ｅ３２ 载体质粒上,使两个片段前后连接成一个全长的病毒 Ｄ Ｎ Ａ。用该质粒转染 Ｍ Ｄ Ｃ Ｃ Ｍ Ｓ Ｂ１ 细胞,经免疫荧光抗体法和 Ｅ Ｌ Ｉ Ｓ Ａ 检测到 Ｃ Ａ Ｖ 病毒,结果证明我们得到了一个 Ｃ Ａ Ｖ 感染性全基因克隆。     

Lentivirus-mediated calcitonin gene-related peptide transfection enhances endothelial differentiation of rat bone marrow mesenchymal stem cells

AIM：To study the effect of calcitonin gene-related peptide (CGRP) gene transfection mediated by lentivirus on the differentiation of rat bone marrow mesenchymal stem cells (MSCs) to endothelial cells. METHODS：Rat bone marrow MSCs were isolated by density gradient centrifugation combined with adherence method. Recombinant lentivirus vector carrying CGRP gene (Lenti-CGRP) was transfected into the MSCs. The secretion of CGRP in culture supernatants of the transfected MSCs was detected using ELISA method. The cells at passage 3 were divided into three groups: CGRP group (MSCs transfected with Lenti-CGRP), CGRP+CGRP8-37 (an antagonist of CGRP receptor) group and control group (MSCs transfected with PBS). The differentiation of the MSCs was detected by immunocytochemical staining for CD31 and factor Ⅷ-related antigen. The proliferation of the cells was measured by cell counting, and the angiogenic ability of the cells was analyzed using Matrigel assay. RESULTS：The proportion of CD31-and factor Ⅷ-related antigen-positive cells in CGRP and CGRP+CGRP8-37 groups was larger than that in control group (P<0.05). The numbers of the cells in CGRP and CGRP+CGRP8-37 groups were significantly increased compared with control group (P<0.05). Lumen-like structures were observed in CGRP and CGRP+CGRP8-37 groups. The above indexes in CGRP+CGRP8-37 group were reduced compared with CGRP group. CONCLUSION: Transfection with CGRP gene induces rat bone marrow MSCs to differentiate into endothelial cells and enhances their proliferation, suggesting that CGRP may play a role in the regulation of angiogenesis.     

小鼠生殖细胞特异基因Oct4启动子片段克隆及报告载体构建

本研究通过PCR方法从小鼠(Mus musculus)基因组中扩增出Oct4启动子的CR4区和CR1区,将其克隆到真核报告载体pEGFP-1,构建了携带Dct4启动子片段的小鼠生殖细胞特异性报告载体CR1,4-pEGFP-1.用该载体转染多种细胞,在荧光显微镜下观察绿色荧光蛋白(EGFP)在细胞中的表达情况,同时以半定量RT-PCR检测转染细胞中Oct4及其它生殖细胞特异性基因的转录情况.结果显示,GFP在小鼠胚胎干细胞、小鼠胚胎成纤维细胞(MEF)和C2C12细胞中均不表达,而在P19细胞和睾丸细胞中表达.RT-PCR结果显示,Oct4在P19、睾丸细胞和生殖干细胞中特异性转录.这表明所构建的绿色荧光蛋白报告载体只在生殖细胞和多能生殖干细胞中内表达,该质粒可作为示踪生殖细胞的工具,同时也可以作为生殖干细胞多能性状态的一个监测标记.     

脂质体介导法转染体细胞效率的优化

为建立脂质体介导的高效体细胞转染体系,采用脂质体TransfastTM包裹编码增强型绿色荧光蛋白(EGFP)的pCMV-EGFP质粒,转染5～13代山羊胎儿成纤维细胞,并用流式细胞仪检测不同DNA剂量、细胞汇合度、血清、转染时间及脂质体与DNA比例等参数对转染效率的影响。实验发现0.75μgDNA按1∶1的脂质体与DNA比例,在无血清条件下转染汇合50%细胞3h,转染效率最高可达40.7%±5%。4h转染时间、细胞汇合80%及转染体系中有血清会降低转染效率。随着DNA剂量的增加,转染效率呈剂量依赖性增高,但山羊成纤维细胞的活细胞数显著下降。实验表明TransfastTM能高效安全地介导外源基因转染山羊成纤维细胞。     

Effects of human growth arrest-specific homeobox gene delivery on proliferation,migration and cell cycle distribution of vascular smooth muscle cells

AIM: To explore a new gene therapeutic strategy for vein graft restenosis by investigating the effects of adenovirus-mediated human growth arrest-specific homeobox (Ad5-hGax) gene delivery on the proliferation, migration and cell cycle distribution of serum-induced rabbit vascular smooth muscle cells (VSMCs). METHODS: The recombinant adenovirus vector containing hGax gene was constructed and transfected into rabbit VSMCs. The expression of hGax in VSMCs was detected by RT-PCR and immunofluorescent staining. Methyl thiazolyl tetrazolium (MTT) assay was used to assess the effect of hGax over-expression on serum-induced proliferation of VSMCs. Wound healing method was applied to examine the distance of serum-induce VSMCs migration. Flow cytometry was employed to analyze the cell cycle distribution. RESULTS: The recombinant adenovirus vector Ad5-hGax was successfully constructed. The results of RT-PCR and immunofluorescent staining revealed that the hGax -transfected cells contained a 174 bp specific fragment of hGax gene and target protein 48 h after transfection. The proliferation of serum-induced VSMCs was significantly inhibited by overexpression of hGax gene as compared with control group. The migration of serum-induced VSMCs was inhibited after hGax gene delivery. Flow cytometry showed that 72 h after serum induction, the cells in G₀/G₁ phase in Ad5-hGax group were significantly increased, whereas the cells in G₂/M+S phase were significantly decreased. CONCLUSION: Overexpression of hGax gene inhibits the proliferation and migration of serum-induced rabbit VSMCs, and arrests the cells in G₀/G₁ phase. It is likely that hGax gene is a potential target for the gene therapy of vein graft restenosis.     

脂质体介导外源基因体外转染牦牛乳腺上皮细胞条件的优化

[目的]优化脂质体介导外源基因体外转染牦牛乳腺上皮细胞的条件。[方法]通过胶原酶消化法和组织块贴壁法,体外分离培养得到牦牛乳腺上皮细胞。采用免疫细胞化学技术检测细胞角蛋白在细胞内的表达。以绿色荧光蛋白为报告基因,通过脂质体介导外源基因转染牦牛乳腺上皮细胞,统计在不同细胞融合度、脂质体浓度、脂质体与质粒的比例、转染时间下的转染效率,寻求最佳转染条件。[结果]牦牛乳腺上皮细胞在细胞融合度为81%～90%,脂质体的量为1.8μl,脂质体与质粒比例为2∶1,转染时间为4h时,转染效率最高。[结论]该研究可为乳腺生物反应器构建提供试验依据。     

外源基因转染真核细胞技术的研究进展

基因转染技术是将外源基因转染真核细胞的一种技术。对外源基因转染真核细胞的目的、意义、转染技术分类、方法及其应用等作一综述。     

Ectopic hTERT gene expression in human bone marrow mesenchymal stem cells

AIM: To investigate the effect of transfection of hTERT gene into human mesenchymal stem cells (MSCs) on their telomerase activity and life-span.METHODS: Human MSCs were transfected with a pEGFP-hTERT plasmid by liposome-mediated transfection. Then the hTERT mRNA expression in MSCs was detected by RT-PCR. The activity of telomerase in transfected MSCs was detected by PCR and ELISA. The telomerase-positive MSCs was cultured in vitro and induced into neuron-like cells with EGF and bFGF. Neuron-specific markers (NF-M, MAP₂) were detected by RT-PCR.RESULTS: hTERT fragment was identified in the hTERT-transfeced cells but not in the untransfected human bone marrow MSCs. The untransfected human MSCs remained telomerase-negative but the hTERT-transfected cells showed robust telomerase activity. The telomerase-negative MSCs entered a nondividing state and senesced after about 20 to 25 passages. In test group, however, telomerase-positive MSCs to date had undergone 35 passages. RT-PCR analysis showed that telomerase-positive MSCs expressed neuron-specific markers, such as NF-M or MAP₂ after induced with EGF and bFGF in vitro. CONCLUSION: Ectopic expression of the hTERT gene in human MSCs reconstitutes telomerase activity. The transfection of hTERT gene into human MSCs extends their replicative life span and maintains their multipotent differentiation capacity.