超声微泡介导转染FKBP12．6基因对小鼠n9c2（2—1）心肌细胞中Ca^2＋浓度的影响

目的：探讨超声微泡介导转染FKBP12．6基因后，对小鼠H9c2（2-1）心肌细胞中Ca^2＋浓度的影响。方法：将pcDNA3．1-FKBP12．6质粒与白蛋白包裹微泡造影剂混合，经超声转染H9c2（2-1）细胞后，通过倒置显微镜观察心肌细胞生长状况的变化；激光共聚焦显微镜检测细胞内Ca^2＋浓度的变化；免疫组织化学方法检测FKBP12．6蛋白的表达。结果：超声触发微泡破裂转染的FKBP12．6基因可在心肌细胞高效表达，细胞生长良好。高表达FKBP12．6的心肌细胞中，总的钙离子浓度增加。结论：超声微泡介导FKBP12．6基因转染心肌细胞，可以明显增加心肌细胞中的Ca^2＋浓度，心肌细胞的收缩能力增强。     

超声微泡介导转染FKBP12.6基因对小鼠H9c2(2-1)心肌细胞中Ca2+浓度的影响

目的:探讨超声微泡介导转染FKBP12.6基因后,对小鼠H9c2(2-1)心肌细胞中Ca2 浓度的影响。方法:将pcDNA3.1-FKBP12.6质粒与白蛋白包裹微泡造影剂混合,经超声转染H9c2(2-1)细胞后,通过倒置显微镜观察心肌细胞生长状况的变化;激光共聚焦显微镜检测细胞内Ca2 浓度的变化;免疫组织化学方法检测FKBP12.6蛋白的表达。结果:超声触发微泡破裂转染的FKBP12.6基因可在心肌细胞高效表达,细胞生长良好。高表达FKBP12.6的心肌细胞中,总的钙离子浓度增加。结论:超声微泡介导FKBP12.6基因转染心肌细胞,可以明显增加心肌细胞中的Ca2 浓度,心肌细胞的收缩能力增强。     

超声靶向微泡破碎介导EGFP基因转染肝癌细胞的影响因素研究

观察超声靶向微泡破碎(ultrasound targeted microbubble destruction,UTMD)在不同转染条件和细胞状态下对肝癌细胞HepG2转染率及细胞活性的影响.体外培养HepG2细胞,随机分为4组:质粒组、微泡+质粒组、超声+质粒组和超声+微泡+质粒组,各组再分为贴壁和悬浮状态2组.悬浮状态的超声+微泡+质粒组根据质粒和微泡浓度不同分为微泡浓度组和质粒浓度组,转染24h后在倒置荧光显微镜下观察绿色荧光蛋白在HepG2细胞中的表达,流式细胞仪测定细胞转染率,MTT法检测细胞活性.结果 在超声声强2w/cm2、占空比20％、照射时间60s的超声参数作用下,质粒5μg/ml、微泡:细胞20∶1时,悬浮状态细胞转染率为7.33％±0.98％,存活率为90.37％±1.80％贴壁状态细胞转染率为1.56％±0.81％,存活率为81.10±1.26％,两者比较有显著差异(P＜0.01).悬浮状态下,提高质粒和微泡浓度至质粒10 μg/ml、微泡:细胞40∶1时转染效率增至15.63％±1.81％,且细胞生存率＞80％.结论 相同转染条件下悬浮状态细胞转染率及存活率明显优于贴壁状态.优化质粒、微泡浓度可进一步提高超声微泡介导的基因转染效率和存活率.     

超声微泡介导pEGFP-N1转染大鼠牙囊细胞:细胞生物学性质相对稳定

背景:利用超声波和微泡对比剂相互作用,产生空化效应和机械效应,破坏细胞膜的完整性,产生暂时性、可逆性的小孔,增加细胞膜的通透性,增强微泡载体对基因的转移,提高基因转染率。目的:探讨在超声波辐照下微泡对比剂介导p EGFP-N1质粒转染SD大鼠乳鼠牙囊细胞的效率及安全性。方法:体外原代培养新生SD大鼠牙囊细胞并传至第4代,在不同条件下采用p EGFP-N1质粒转染乳鼠牙囊细胞。以不同的超声辐照时间(15,30,45,60 s)和辐照强度(0.5,1 W/cm2)两两组合进行辐照,筛选较高转染效率的参数组合并应用于后续实验。实验分组为质粒组、微泡+质粒组、超声+质粒组、超声+微泡+质粒组和脂质体+质粒组。转染48 h后倒置荧光显微镜观察p EGFP表达,MTT法检测转染后的乳鼠牙囊细胞增殖抑制率。结果与结论:超声强度为0.5 W/cm2且辐照时间为30 s时转染率明显高于其他超声参数组合。该条件下超声微泡介导p EGFP-N1质粒对乳鼠牙囊细胞的转染率高于传统脂质体介导的转染率,且对细胞活力无明显影响。提示超声微泡能安全、高效介导p EGFP-N1质粒转染大鼠牙囊细胞,其细胞生物学性质相对稳定,可为牙周组织工程提供一种较理想的基因转染方法。     

经心包腔途径转染提高大鼠体内心肌细胞转染的效率*

背景：如何获得安全、有效、广泛心肌组织的转染一直是国内外学者研究的热点。 目的：探讨能够改善动物水平心肌组织非病毒载体的转染效率、增强基因导入靶向性的方法。 方法：以β半乳糖苷酶质粒PLacZ作为报告基因,将Wistar大鼠随机分为5组：①空白组。②心包腔内组：心包腔注射质粒+微泡+酶混悬液,超声导入。③心包腔内阴性对照组：以生理盐水代替质粒干预。④舌下静脉组：舌下静脉注射质粒+微泡混悬液,超声导入。⑤舌下静脉阴性对照组：以生理盐水代替质粒干预。注射6 d后处死,进行心、肺、肝、肾组织的X-gal染色。 结果与结论：转染6 d后,仅有心包腔内组大鼠的部分心肌细胞在心尖、心室及心房水平可见明显的蓝染,其他各组大鼠心肌X-gal染色为阴性;各组大鼠肺、肝、肾组织X-gal染色均为阴性。提示采用心包腔内途径转染、再辅以超声微泡导入以及酶类的使用,可明显改善质粒对在体心肌细胞的转染效率,且不伴有心外组织目的基因的表达,具有较好的靶向性。关键词：心包;心肌细胞;siRNA;RNAi;转染;基因 doi:10.3969/j.issn.1673-8225.2012.15.027     

造影剂、超声波介导的基因治疗技术

目前基因治疗受阻于缺乏安全有效的载体。病毒类载体和非病毒类载体最大的不足之处在于不安全和转染效率低。超声波作为一种物理转染方法会造成组织损伤。近年来,超声造影剂的出现使研究者对超声波介导的基因转染技术有了新的认识。微气泡作为一种超声造影剂能携带基因物质,在超声波的作用下,“载体”微泡破裂,并在经超声辐照的区域高浓度释放其所携带的基因物质。同时,微气泡破裂会导致局部组织细胞膜通透性增高,从而使外源性基因更易被摄取。     

白蛋白微泡促进报告基因在细胞表达的实验研究

目的: 探讨白蛋白微泡作为非病毒载体在基因传输中的作用。方法:6孔板培养脐静脉内皮细胞(EC)和血管平滑肌细胞(VSMC),每孔加pcDNA3.1/His/LacZ质粒20 μg,加不同浓度微泡或不加微泡,超声条件为连续波,频率2MHz,机械指数1.8,照射时间1 min,48 h后计算蓝染细胞百分率和β-半乳糖苷酶活性。另以不同浓度微泡及超声照射时间处理细胞,测定细胞增殖情况。结果:与单纯超声质粒组相比,含微泡组蓝染细胞率增加约10-15倍(其中内皮细胞组11.6倍,平滑肌细胞组15.2倍),报告基因表达定量增加近8倍。微泡浓度为10％时细胞转染效率最高。超声照射对细胞增殖无影响,微泡浓度为50％时有明显的细胞毒作用。结论:白蛋白微泡在超声作用下能明显增加基因的传输效率,有可能成为一种安全有效的基因治疗的载体。     

超声破坏微泡法介导增强型绿色荧光蛋白质粒转染兔股骨头组织的安全性及可行性

背景：超声微泡转染系统已尝试于体内多部位的基因转染,但尚未见有用于骨部位基因转染的报告。 目的：观察超声破坏微泡法介导增强型绿色荧光蛋白质粒转染兔股骨头组织的效率及可行性。 方法：将日本大耳白兔按随机均分为裸转染组,预照射+裸转染组,超声定位转染组,预照射+超声定位转染,重复定位转染组。其中前2组不给予超声定向转染照射,后3组利用超声微泡破裂法介导增强型绿色荧光蛋白质粒,定向基因转染兔股骨头。各组转染1周后,于荧光显微镜下观察增强型绿色荧光蛋白在股骨头组织中的表达情况。 结果与结论：超声定位转染组,预照射+超声定位转染,重复定位转染组均有增强型绿色荧光蛋白表达,且复定位转染组增强型绿色荧光蛋白质粒在兔股骨头内的转染效率明显高于其他组(P < 0.01)。超声定位转染组,预照射+超声定位转染,重复定位转染组兔超声照射部位软组织和骨组织切片未观察到明显损伤病灶。结果证实,超声微泡破裂法能安全、有效实现增强型绿色荧光蛋白质粒在兔股骨头组织的转染。     

超声微泡联合脂质体介导双自杀基因杀伤 MCF-7 细胞的实验研究简

目的探讨超声辐照微泡联合脂质体介导双自杀基因（CD/TK）对MCF-7细胞的体外杀伤作用。方法将培养的MCF-7细胞分为5组：裸质粒组、脂质体组、超声辐照微泡组、超声辐照脂质体组、超声辐照微泡联合脂质体组。转染DEGFP-KDRp-CD／TK质粒于MCF-7细胞.用荧光显微镜及流式细胞仪检测转染效率。转染后,再分为空白对照组、未转染组、转染组;未转染组和转染组又各分为3个亚组,给予前药丙氧鸟苷（GCV）、5-氟胞嘧啶（5-Fc）、GCV＋5-Fc。四甲基偶氮唑盐（MTT）法检测双自杀基因对MCF-7细胞的体外杀伤作用。结果超声辐照微泡联合脂质体组绿色荧光蛋白（GFP）表达最多、最强。超声辐照微泡联合脂质体组转染率（39.59％±1.19％）最高（P〈0.05）。MTr检测细胞抑制率结果显示,转染组细胞抑制率明显高于未转染组（P〈0.01）,转染组中联合用药组细胞抑制率明显高于单一用药组（90.77％±2.68％vs64.75％±2.27％、67.81％±2.43％：P〈0.05）。转染组各前药组细胞抑制率均显著高于超声辐照微泡联合脂质体对MCF-7细胞的转染率（P〈0.05）。结论超声辐照微泡联合脂质体能明显提高基因转染效率,是较理想的乳腺癌基因治疗策略。     

超声微泡介导Itch基因沉默增强T细胞对肺腺癌细胞LA795免疫杀伤作用

目的利用超声介导微泡破裂技术(UTMD)沉默T细胞Itch基因表达,观察转染T细胞对肺腺癌细胞LA795的体外免疫杀伤效率。方法磁珠分选纯化T细胞,构建靶向Itch基因的shRNA表达质粒,超声微泡介导转染48 h后,荧光显微镜和流式细胞仪评估细胞转染效率,Western blot检测Itch蛋白表达。转染72 h后,酶联免疫吸附法(ELISA)检测细胞上清液中IL-2和IFN-γ分泌水平,观察对比单纯T细胞、阴性对照T细胞及转染T细胞与小鼠肺腺癌细胞LA795共培养时肿瘤杀伤率。结果利用UTMD技术介导shRNA转染效率达到52.3%±3.8%,Itch蛋白表达能够有效被抑制。转染72 h后,超声微泡介导沉默Itch基因显著增加T细胞因子IL-2和IFN-γ分泌水平(P0.05);与空白组或阴性对照组T细胞相比,在不同的靶效比水平(10∶1、20∶1、40∶1),转染T细胞杀瘤活性均明显增高(P0.05)。结论利用UTMD技术介导shRNA转染能有效沉默Itch基因表达,促进T细胞免疫活性,增强T细胞对小鼠肺腺癌细胞LA795的体外免疫杀伤效率。     

Gene delivery from supercharged coiled-coil protein and cationic lipid hybrid complex

A lipoproteoplex comprised of an engineered supercharged coiled-coil protein (CSP) bearing multiple arginines and the cationic lipid formulation FuGENE HD (FG) was developed for effective condensation and delivery of nucleic acids. The CSP was able to maintain helical structure and self-assembly properties while exhibiting binding to plasmid DNA. The ternary CSP·DNA(8:1)·FG lipoproteoplex complex demonstrated enhanced transfection of β-galactosidase DNA into MC3T3-E1 mouse preosteoblasts. The lipoproteoplexes showed significant increases in transfection efficiency when compared to conventional FG and an mTat·FG lipopolyplex with a 6- and 2.5-fold increase in transfection, respectively. The CSP·DNA(8:1)·FG lipoproteoplex assembled into spherical particles with a net positive surface charge, enabling efficient gene delivery. These results support the application of lipoproteoplexes with protein engineered CSP for non-viral gene delivery.     

Enhanced expressions and histological characteristics of intravenously administered plasmid DNA in rat lung

Cationic liposome-mediated gene transfection is a promising method for gene therapy. In this study, the transfection efficiency and histological patterns were evaluated in rat lung after intravenous administration via femoral vein of naked plasmid DNA, naked plasmid DNA with pretreatment of DOTAP, and DOTAP-cholesterol-plasmid DNA complex. Plasmid DNA encoding bacterial LacZ gene was used. For quantification of LacZ gene expression, beta-galactosidase assay was performed. For histologic examination, X-gal staining and immunohistochemical staining for transfected gene products were performed. Pretreatment of DOTAP prior to the infusion of naked plasmid DNA increased transfection efficiency up to a level comparable to DOTAP-cholesterol-plasmid DNA complex injection. Transfected genes were mainly expressed in type II pneumocytes and alveolar macrophages in all animals. We conclude that the high transfection efficiency is achievable by intravenous administration of naked plasmid DNA with pretreatment of DOTAP, to a level comparable to DOTAP-cholesterol-plasmid DNA complex. In this regard, naked plasmid DNA administration with pretreatment of DOTAP could be a more feasible option for intravenous gene transfer than DOTAP-cholesterol-plasmid DNA complex, in that the former is technically easier and more cost-effective than the latter with a comparable efficacy, in terms of intravenous gene delivery to the lung.     

VEGF真核表达载体的构建及在内皮与心肌细胞内的表达

目的：探讨外源性人VEGF165基因在内皮细胞与心肌细胞内表达的可行性。方法：构建了(vaseular endothelium growth factor,VEGF)与增强型绿色荧光蛋白(enhanced green fluorescent protein，EGFP)基因其表达载体pIRES2—FGFP—VEGF165，以脂质体法转染内皮细胞和心肌细胞，采用荧光显做镜检测内皮细胞与心肌细胞中EGFP的表达，同时利用免疫组织化学方法检测VEGF的表达。结果：成功地构建了真核表达载体pIRES2—EGFP—hVEGF165，采用脂质体法转染内皮细胞与心肌细胞后，经荧光显微镜观察，可见细胞内有EGFP的表达，同时经免疫组化证实有VEGF的表达。结论：采用脂质体法可以成功地将外源性VEGF165基因转染到内皮细胞与心肌细胞中，并进行表达。本研究为今后利用VEGF基因治疗心肌缺血等疾病提供了实验基础。     

超声靶向微泡破坏联合核因子κB结合基序促进SDF-1α质粒转染血管内皮细胞

目的 应用超声靶向微泡破坏技术（UTMD）和核因子κB（NF-κB）结合基序分别促进人基质细胞衍生因子-1α（SDF-1α）质粒进入细胞质和细胞核,提高对血管内皮细胞的转染效率.方法 构建含NF-κB结合基序的人SDF-1α质粒（phSDF-1α-NF-κB）和不含NF-κB结合基序的人SDF-1α质粒（phSDF-1α）,用核酸染料Cy3标记后在优化的UTMD条件下分别转染人脐静脉血管内皮细胞.流式细胞仪检测质粒入胞效率;荧光显微镜观察质粒入核情况;RT-PCR、Western印迹和ELISA分别从基因水平和蛋白水平检测SDF-1α质粒的表达.比较两种质粒的入胞率、入核率以及表达率以评价UTMD和NF-κB结合基序对转染的作用.结果 UTMD能显著提高质粒的入胞效率（81％±7％）,同时保持较高细胞存活率（86％±6％）.含NF-κB结合基序组的质粒入核效率和蛋白表达效率均较不含NF-κB结合基序组显著提高[65％±12％比10％±3％,（63±10）比（15±5）μg/g蛋白,均P＜0.01].结论 UTMD联合NF-1κB结合基序转染系统通过提高质粒的人胞和入核效率能显著提高SDF-1α质粒对血管内皮细胞的转染效率.     

A calcium phosphate-based gene delivery system

Although nonviral vectors have lower transfection efficiency than viral vectors, the excellent safety profile of nonviral vectors is appealing for gene therapy. An efficient, simple nonviral vector gene delivery system has been designed that includes plasmid DNA-calcium phosphate precipitates (pDNA-CaP) and porous collagen spheres (Cultispherestrade mark). The hypothesis for this study was the pDNA-CaP would achieve efficient plasmid DNA transfection and the porous collagen spheres would provide a suitable delivery carrier system for three-dimensional (3D) administration. To test the hypothesis, plasmid DNA including the LacZ reporter gene encoding beta-galactosidase was precipitated with CaP to form particles of compacted LacZ-CaP and delivered directly or by Cultispherestrade mark to cells in vitro. The transfection efficiency was determined by beta-galactosidase gene expression. Results indicated that pLacZ-CaP promoted 25-84% of transfection efficiency in a broad cell line spectrum and in flexible experimental conditions. Maximum transfection efficiency was achieved by having mostly nano-sized partles (50-200 nm in diameter) of pDNA-CaP precipitates. Seeding density of 0.7-4 x 10(4) cells/cm2 provided sufficient transfection efficiency, and storage of pDNA-CaP at 4 degrees C was most efficient to preserve transfection efficacy for up to 3 days. The pDNA-CaP worked well in the presence of serum and serum-free conditions and was less cytotoxic than the liposomes. Cultispherestrade mark carrying plasmid LacZ-CaP was an effective 3D system for gene delivery. The technique described here is a simple and safe procedure to deliver genes, and may have application to regenerate bone and other tissues.     

超声－微气泡介导的基因转染研究进展

能否成功高效地转染靶基因对于基因治疗的效果具有决定性的影响。微气泡是具有稳定的封装壳,直径为微米量级的小气泡,已作为超声造影剂被广泛应用。微气泡在超声脉冲的作用下可以在靶区释放其携带的基因并使之转染,同时超声脉冲产生的热效应和空化效应能提高转染率。若将微气泡与磁性纳米颗粒结合,还可以进一步提高转染率和转染精度,是一种理想、安全的基因载体。本文综述了由超声－微气泡介导的基因转染在近5年的主要研究成果。对影响转染率的主要因素如微气泡种类、超声辐照条件、基因及受体类型等方面做了详细的论述,并对微气泡介导基因转染过程中的安全性、长效性和差异性等问题进行了讨论。     

Keratinocyte Growth Factor Gene Electroporation into Skeletal Muscle as a Novel Gene Therapeutic Approach for Elastase-Induced Pulmonary Emphysema in Mice

Pulmonary emphysema is a progressive disease with airspace destruction and an effective therapy is needed. Keratinocyte growth factor (KGF) promotes pulmonary epithelial proliferation and has the potential to induce lung regeneration. The aim of this study was to determine the possibility of using KGF gene therapy for treatment of a mouse emphysema model induced by porcine pancreatic elastase (PPE). Eight-week-old BALB/c male mice treated with intra-tracheal PPE administration were transfected with 80 μg of a recombinant human KGF (rhKGF)-expressing FLAG-CMV14 plasmid (pKGF-FLAG gene), or with the pFLAG gene expressing plasmid as a control, into the quadriceps muscle by electroporation. In the lung, the expression of proliferating cell nuclear antigen (PCNA) was augmented, and surfactant protein A (SP-A) and KGF receptor (KGFR) were co-expressed in PCNA-positive cells. Moreover, endogenous KGF and KGFR gene expression increased significantly by pKGF-FLAG gene transfection. Arterial blood gas analysis revealed that the PaO₂ level was not significantly reduced on day 14 after PPE instillation with pKGF-FLAG gene transfection compared to that of normal mice. These results indicated that KGF gene therapy with electroporation stimulated lung epithelial proliferation and protected depression of pulmonary function in a mouse emphysema model, suggesting a possible method of treating pulmonary emphysema.