Association analysis of the cholecystokinin type A receptor gene in schizophrenia

Schizophrenia is characterized by clinical heterogeneity and genetic heterogeneity. 1 Because dopamine(DA)overactivity has been thought, over the past 40 years, to play a role in the pathophysiology of schizophrenia, its receptors and metabolic enzymes have been regarded as potentially involved in schizophrenia. 2 However,disease-causing variants among the genes coding for dopamine receptors and the enzymes related to DA have not been found. Cholecystokinin A receptor (CCK-AR)coexists with DA in the same neurons of the midbrain limbic system, as well as the access to the substantia nigra and the corpus striatum, and it acts as a mediator modulating dopaminergic activity. 3 Two CCK receptors,CCK-AR and CCK B receptor (CCK-BR) have been identified. CCK-AR in the medial posterior nucleus accumbens increases DA release, while CCK-BR in the anterior nucleus accumbens decreases DA release. 4 The former has potential effects on human neuropsychiatric diseases linked to DA, such as schizophrenia. Recently,several studies found that the Pst I polymorphic site present in the boundary between intron 1 and exon 2 of the CCK-AR gene is associated with some symptoms of schizophrenia. This finding is particularly important for uncovering the genetic etiology of schizophrenia, although the mechanism linking this polymorphic site to the disease remains unclear. The present work is an attempt to confirm the genetic association between the CCK-AR gene and schizophrenia.     

低剂量辐射诱导EL-4淋巴瘤细胞凋亡及细胞周期进程适应性反应的剂量率效应

目的：观察低剂量辐射诱导EL-4淋巴瘤细胞凋亡及细胞周期进程适应性反应的剂量率效应,以揭示低剂量辐射生物效应及其诱导适应性反应的可能机制。方法：实验分D2组（攻击剂量）、D1（诱导剂量）+ D2组和假照组。用X射线照射离体EL-4淋巴瘤细胞,其D1为75 mGy（剂量率6.25~200.00 mGy•min^-1）,D2为1.5 Gy（剂量率287 mGy/min）,D1和D2间隔6 h。通过流式细胞仪检测其细胞凋亡和细胞周期进程的变化。结果：当D1剂量率为6.25~50.00 mGy,D1 + D2组细胞凋亡百分数明显低于D2组（P<0.05）G₀/G₁期细胞百分数明显低于D2组（P<0.01）,而S期细胞百分数不同程度高于D2组。结论：D1为75 mGy（剂量率6.25~50.00 mGy•min^-1）,D2为1.5 Gy（剂量率287 mGy•min^-1）、D1和D2间隔6 h,可诱导体外EL-4淋巴瘤细胞凋亡和细胞周期进程的适应性反应。     

aFGF核转位序列的敲除后蛋白结构稳定性及促分裂活性的变化

目的 通过比较野生及重组人类酸性成纤维细胞生长因子（waFGF,raFGF）的蛋白结构稳定性、细胞增殖活性的影响,探讨核转位序列的敲除对aFGF促分裂活性的影响.方法 Western-blot检测waFGF和raFGF两种蛋白结构稳定性;MTT法检测NIH3T3细胞增殖,即促细胞分裂活性;流式细胞术检测其对细胞周期的影响;同时,检验肝素（HS）对waFGF和raFGF有关生物学作用.结果 waFGF的结构稳定性大于raFGF;细胞增殖实验表明,waFGF的促分裂活性大于raFGF,P＜0.05.在肝素的参与下,waFGF和raFGF表现出更大的促分裂活性;结论 与waFGF比,raFGF的结构稳定性小于waFGF,具有较弱的促分裂性,仍具有刺激DNA合成和细胞增殖的能力.肝素具有增强aFGF活性的作用,可作为aFGF体外实验中模仿机体内环境的辅助因子.     

人血管内皮细胞生长因子基因体外转染皮肤成纤维细胞后的表达效应

目的：观察外源性人血管内皮细胞生长因子基因导人正常真皮成纤维细胞后，能否表达及分泌血管内皮细胞生长因子，为进一步构建转VEGF165基因组织工程皮肤在创伤修复中的应用提供新移植物。 方法：实验于2001—06／2005—06在长春吉林大学完成。①真核表达载体pcDNA3．0-hVEGF165的扩增、纯化和鉴定过程为大肠杆菌DH5a感受态细胞的制备→pcDNA3．0-hVEGF165质粒DNA细菌转化→pcDNA3．0-hVEGF165质粒大量制备（碱裂解法）-质粒纯化-质粒含量纯度测定。提取的质粒载体用EeoRⅠ和xbaⅠ双酶切，琼脂糖凝胶电泳鉴定。②选取清洁级新生日本大耳白兔2只，无菌条件下取新生兔皮肤，尽量去除皮下组织，切成宽0．3cm小条块，Ⅰ型胶原酶消化，进行真皮成纤维细胞的分离与培养。脂质体介导真核表达质粒pcDNA3．0-hVEGF165转染体外培养的兔皮肤成纤维细胞，经G418筛选，获得阳性转染细胞克隆，并进行传代扩增。③酶联免疫吸附法检测转染后不同时间段的血管内皮细胞生长因子蛋白表达水平；原位杂交显示转基因细胞内VEGF165 mRNA的表达情况；流式细胞仪检测细胞周期和凋亡情况；透射电子显微镜观察转染后真皮成纤维细胞的超微结构。 结果：①质粒酶切鉴定结果：提取的质粒经双酶切、琼脂糖凝胶电泳鉴定后可得到5．4kb和0．57kb两个片段，与原质粒图谱符合，表明所提取的质粒为重组质粒pcDNA3．0-VEGF165。②pcDNA3-hVEGF165基因转染真皮成纤维细胞情况：共进行15次转染试验，35孔（皿）均有G418抗性集落形成，表明pcDNA3．0-hVEGF165经脂质体介导可有效转染正常皮肤成纤维细胞。③血管内皮细胞生长因子蛋白的表达：pcDNA3．0-hVEGF165转染成纤维细胞后，24h即有较高水平的血管内皮细胞生长因子蛋、白表达，高达（3280&;#177;2054）ng／L，并于48，72h呈下降趋势。④血管内皮细胞生长因子cDNA原位杂交检测结果：转染后成纤维细胞可见散在的阳性细胞表达hVEGF mRNA。G418应用2-4周后，可成功筛选出转基因成纤维细胞克隆，筛选后可见大量阳性的转染细胞表达hVEG FmRNA。⑤成纤维细胞的细胞周期分布及凋亡检测：转染后成纤维细胞S期细胞比例增加，G1和G2期细胞减少，表明细胞DNA的合成以及细胞的增殖活动加强。但细胞凋亡率逐渐升高。转染前为1．26％，转染后2d为2．64％，至12代时高达17135％。⑥转染后成纤维细胞超微结构观察：细胞表面有较多微绒毛，核呈不规则形，胞质内可见较多的粗面内质网、线粒体，沿膜可见一些膜包被颗粒。 结论：真核表达质粒pcDNA3．0-hVEGF165成功导人家兔皮肤成纤维细胞，在短时期内可高水平地表达分泌血管内皮细胞生长因子，在治疗缺血性疾病和促进创伤修复及以其作为种子细胞构建转基因组织工程皮肤治疗皮肤缺损等方面显示出较好的应用前景。     

pcEgr-hp53辐射诱导表达载体的构建及其体外抗肿瘤的作用

目的构建辐射诱导表达载体pcEgr-hp53，并研究其体外稳定转染联合X射线照射对人卵巢癌SKOV3细胞增殖的抑制作用及其凋亡的影响。方法将野生型p53cDNA全长插人pcDNA3．1质粒的多克隆位点，用Egr-1的启动子替代pcDNA3-1质粒的CMV启动子，构建成pcEgr-hp53重组质粒；通过脂质体介导转染法将重组质粒pcEgr-hp53和pcDNA3．1分别转染入SKOV3细胞株，细胞株命名为SKOV3-hp53及SKOV3-vect，并经CA18筛选稳定克隆并扩增培养，两组接受不同剂量X射线照射，观察其对肿瘤细胞生长及其凋亡的影响。结果经限制性内切酶酶切鉴定，辐射诱导表达载体pcEgr-hp53构建正确，稳定转染pcEgr-hp53联合X-射线照射可明显抑制肿瘤细胞的增殖，并诱导肿瘤细胞捅亡。结论本研究成功构建了辐射诱导表达载体DeEgr-hP53，体外基因．放射联合治疗诱导肿瘤细胞凋亡明显增多，具有显著的肿瘤抑制作用。本研究将为提高临床恶性肿瘤放疗疗效奠定了理论和实验基础。     

pEgr-hp53体外稳定转染联合辐射对人肺腺癌A549细胞周期进程及增殖的影响

目的探讨pEgr-hp53重组质粒体外稳定转染联合辐射对人肺腺癌A549细胞周期进程及增殖的影响,阐明其抑制肿瘤细胞增殖的机制。方法脂质体包裹重组质粒pEgr-hp53体外转染A549细胞,G418筛选稳定表达细胞株并扩增培养,采用细胞计数法检测肿瘤细胞增殖速度,流式细胞术检测肿瘤细胞周期的变化。结果经pEgr-hp53体外转染A549细胞10到20d,G418筛选得到稳定表达的细胞株,联合X射线照射可明显抑制A549细胞的体外增殖,细胞周期进程明显改变,G1期和G2期发生阻滞。结论提示pEgr-hp53体外稳定转染联合辐射可使人肺腺癌A549细胞周期阻滞于G1期和G2期,并可抑制肿瘤细胞增殖,本研究为提高肿瘤放射治疗效果提供新的治疗方案奠定了理论基础和实验依据。     

电离辐射对Jurkat T细胞周期进程的影响

目的：探讨电离辐射诱导Jurkat T细胞损伤过程中细胞周期进程的变化规律。方法：采用流式细胞术 (FCM) 检测低剂量（0.075 Gy）和较大剂量（0.5、1.0、2.0、4.0及6.0 Gy）X射线照射后Jurkat T细胞周期进程变化的时间-效应关系和剂量-效应关系。结果：时间-效应关系研究发现,2.0 Gy X射线照射后Jurkat T细胞相继发生S期延迟和G₂期阻滞,S期细胞百分率于照射后立即增加(P<0.001),而G₂+M期细胞百分率照射后8 h开始显著增加（P<0.001）。剂量-效应关系研究发现,75 mGy低剂量X射线照射即可诱导Jurkat T细胞发生S期延迟（P<0.001）和G₂期阻滞（P<0.05）;0.5~6.0 Gy较大剂量X射线照射后,Jurkat T细胞发生S期延迟和G₂期阻滞。与假照组相比较,G₀/G₁期细胞百分率显著降低（P<0.001）,在0.5~6.0 Gy内具有剂量依赖性,而S期和G₂+M期细胞百分率显著升高（P<0.05或P<0.001）。结论：X射线照射可以改变Jurkat T细胞周期进程,诱导其相继发生S期延迟和G₂期阻滞,在0.5~6.0 Gy内具有剂量依赖性。     

治疗基因相关问题的探讨

基因在体内表达是基因治疗的基础.按疾病治疗需要对目的基因的表达进行精确的调控,一直是基因治疗研究中的难题,也是目前载体系统存在的最大问题.在疾病的基因治疗过程中,除能确保目的基因足量、稳定表达外,还要根据疾病的不同或其症状改善情况,对基因表达(gene expression)的时间和剂量进行调控.     

Enhanced effects of TRAIL-endostatin-based double-gene-radiotherapy on suppressing growth, promoting apoptosis and inducing cell cycle arrest in vascular endothelial cells

This study examined the effects of TRAIL-endostatin-based gene-radiotherapy on cellu-lar growth, apoptosis and cell cycle progression in human vascular endothelial cells ECV304 in vitro. The expression of TRAIL and endostatin protein in ECV304 cells was detected by ELISA after the transfection of recombinant plasmid pshuttle-Egr1-shTRAIL-shES and X-ray irradiation. Then MTT assay was used for determining the cellular proliferation, and flow cytometry (FCM) plus Annexin V and propidium iodide (PI) double-staining or PI single-staining were employed for the detection of apoptosis and cell cycle progression. The results showed that expression of TRAIL and endostatin protein exhibited a time- and dose-dependent change in ECV304 cells after pshut-tle-Egr1-shTRAIL-shES transfection in conjunction with irradiation. In the TRAIL-endostatin-based single- or double-gene-radiotherapy, the cell viability declined in a time- and dose-dependent manner, the percentage of cells at G2/M phase and apoptotic rate was increased, and the percentage of cells at G0/G1 phase was lowered as compared with those receiving radiotherapy alone. Moreover, TRAIL-endostatin-based double-gene-radiotherapy demonstrated better effects on growth inhibition, promotion of apoptosis and induction of cell cycle arrest in ECV304 cells than sin-gle-gene-radiotherapy.