外源EGFP和hTH基因在恒河猴骨髓源神经干细胞内的稳定表达

目的构建携带人酪氨酸羟化酶(hTH)的荧光真核表达质粒-pEGFP-C2-hTH,转染骨髓基质细胞源神经干细胞(BMSCs-D-NSCs),观察外源EGFP和hTH基因在BMSCs-D-NSCs中的表达情况。方法应用基因重组技术,将pWAV2-TH中的TH目的基因亚克隆到荧光真核表达载体 pEGFP-C2,以酶切和测序鉴定重组质粒pEGFP-C2-hTH的正确性:pEGFP-C2-hTH经NucleofectorTM 核转染仪转染培养的恒河猴BMSCs-D-NSCs,24 h后观察绿色荧光蛋白的瞬时表达情况,10 d后行 TH单克隆抗体的免疫组化和TH基因的RT-PCR。结果 (1)酶切、PCR和DNA序列鉴定均证实插入片段的正确性;(2)细胞转染24 h后,荧光显微镜下可观察到绿色荧光蛋白(GFP)的表达,观察到 80％的转染细胞发出绿色荧光;转染10 d后细胞的RT-PCR检测到hTH基因的表达,TH单克隆抗体免疫组化结果显示转染细胞呈阳性染色,同时在荧光显微镜下观察到绿色荧光。结论构建的 hTH荧光真核表达重组质粒pEGFP-C2-hTH,经电转染方法转染至BMSCs-D-NSCs内,成功表达hTH 和EGFP,为BMSCs-D-NSCs基因治疗提供了实验基础。     

帕金森病基因治疗的实验研究

帕金森病(PD)的主要病理特征是中脑黑质多巴胺能神经元变性,表达的酪氨酸羟化酶(TH)减少或者活性降低。目前外源性多巴是最有效的抗PD药物,但常在数年后失去其有效的治疗作用。用胚胎脑细胞移植虽有效果,但胚胎脑来源困难。因此需要探索新的有效治疗方法。本研究将遗传修饰的成肌细胞植入偏侧PD鼠模型纹状体进行基因治疗。移植转TH基因的成肌细胞(治疗组,n=24)和未经遗传修饰的成肌细胞(对照组,n=10)于偏侧PD鼠损毁侧纹状体。用阿朴吗啡(APO)诱发旋转行为,RT-PCR、TH免疫组化检测TH基因的表达和TH蛋白的合成以及HPLC-ECD检测纹状体多巴胺及代谢产物含量以此评估基因治疗的效果。治疗组移植治疗后APO诱发的旋转行为明显改善(P<0.01),且可持续13个月,而对照组APO诱发的旋转行为无改善(P>0.05),应用RT-PCR、TH免疫组化和HPLC-ECD在治疗组移植部位检测到TH基因的表达、TH蛋白的合成和移植侧纹状体部多巴胺及其代谢产物含量增高。遗传修饰的成肌细胞能够在体内长时间、有效地表达TH,并改善PD鼠的病理行为,是PD基因治疗的合适靶细胞之一。     

骨髓基质细胞移植治疗帕金森病河猴的实验研究

目的 探讨以骨髓基质细胞(BMSCs)为供体移植治疗帕金森病(PD)模型恒河猴的可行性.方法 应用立体定向手术毁损单侧黑质建立恒河猴PD模型,采用加拿大评分和单光子发射计算机断层成像术(SPECT)分别观察恒河猴行为学和大脑黑质多巴胺转运蛋白(DAT)的变化,免疫荧光双标染色检测恒河猴黑质移植侧和正常侧BMSCs的分化状态.结果 移植BMSCs后恒河猴的PD综合征症状逐渐加重;SPECT检测显示恒河猴移植BMSCs前后黑质双侧DAT无明显变化,但免疫荧光显示移植后BMSCs分化为多巴胺(DA)能神经元的比例高达25%.结论 BMSCs无法作为有效的移植供体治疗PD,其可行性尚需进一步研究.     

丘脑底核脑深部电刺激治疗帕金森病的功能显像研究

目的通过单光子放射计算机断层扫描(SPECT)功能显像研究探讨丘脑底核脑深部电刺激(STN DBS)对纹状体多巴胺系统代谢的影响。方法对2只偏侧帕金森病(PD)模型猴及4例临床PD患者在施行单侧STN DBS手术前后给予SPECT检查,测定纹状体区域多巴胺转运体(DAT)及多巴胺D2受体(D2R)含量变化。结果STN DBS电刺激后2只偏侧PD模型猴及3例疗效较好的PD患者纹状体区DAT含量明显增加,2只PD模型猴D2R含量逐渐下降,4例患者D2R检测与术前无统计学意义。结论STN DBS可以明显改善PD症状,SPECT检查显示刺激侧纹状体区DAT含量升高,提示STN DBS可能改善了刺激侧纹状体区多巴胺的代谢,这可能是STN DBS的作用机制之一。     

脑内植入APA-BCC的偏侧帕金森病样猴的多巴胺D2受体功能影像观察

目的 观察海藻酸钙-多聚赖氨酸-海藻酸钙微囊化牛肾上腺嗜铬细胞(APA-BCC)脑内移植后偏侧帕金森病(PD)样猴行为的改善及纹状体区D2受体的活性。方法 1只MPTP诱发右侧PD样猴接受右侧脑纹状体区APA-BCC植入；观察移植后的行为变化；于移植后48个月时行^11C-raclopride标记多巴胺D2受体活性的PET检查。结果 APA-BCC脑内移植后48个月时，偏侧PD样猴的异常行为仍得到明显纠正；脑PET三维图像显示移植侧纹状体区D2受体活性较对侧明显增高。结论 APA-BCC脑内移植可长时间地纠正偏侧PD样猴的异常行为并升高移植区突触后膜多巴胺D2受体的活性。     

立体定向下恒河猴偏侧部分损伤性帕金森病模型的制作

目的　制作一种能保留内侧前脑束 (MFB)内的多巴胺 (DA)神经纤维的偏侧部分损伤性帕金森病(PD)猴模型。方法　以 6 羟多巴 (6 OHDA)溶液对 12只恒河猴右侧黑质致密部行多靶点毁损。术后进行行为学观察、MR、PET、SPECT检查及酪氨酸羟化酶 (TH)的免疫组织化学染色。结果　猴术后符合帕金森病表现。MR示靶点准确位于黑质 ,PET示毁损侧黑质纹状体区代谢减低。TH染色示黑质致密部DA能神经元毁损达 80 %以上 ,而中脑腹侧被盖区和MFB区的DA能神经纤维保留较好。结论　用立体定向注射 6 OHDA毁损一侧黑质致密部的方法可制作出偏侧部分损伤性帕金森病恒河猴模型     

帕金森病鼠纹状体内羊膜移植对C-fos表达的影响

目的:观察非多巴胺能组织-羊膜细胞移植是否能纠正帕金森病(PD)鼠纹状体多巴胺(DA)受体的超敏感性。方法:在羊膜细胞植入PD大鼠模型纹状体后第12周,用免疫组化法检测阿朴吗啡诱发的C-fos蛋白。结果:经图像分析,发现成活羊膜细胞移植与死羊膜细胞移植相比,能显著减少移植侧纹状体中C-fos的表达量。结论:成活羊膜细胞移植能够纠正多巴胺受体的超敏现象。而且,多巴胺受体受影响的范围大大超过了细胞移植诱发宿主残存多巴胺神经元再生的范围。     

小鼠胚胎干细胞诱导的神经前体细胞纹状体移植对PD大鼠的治疗作用

目的 观察来源于小鼠胚胎干细胞的神经前体细胞移植PD大鼠纹状体后的存活、分化以及细胞移植对PD大鼠的治疗作用。方法 采用无血清方法将小鼠胚胎干细胞定向诱导为神经前体细胞，免疫组化技术观察移植细胞的存活、分化。结果 胚胎体在N2选择性培养基选择生长5d后，85％以上的小鼠胚胎干细胞分化为nestin阳性的神经前体细胞。移植到PD大鼠纹状体后大部分神经前体细胞存活良好，移植细胞分别保持为未分化的nestin阳性的神经前体细胞和TH阳性的神经元。移植后3周，PD大鼠的旋转次数明显减少。结论 胚胎干细胞来源的神经前体细胞移植PD大鼠纹状体后能分化为TH阳性的神经细胞，对PD有治疗作用。     

转基因成肌细胞脑内移植后帕金森病大鼠纹状体多巴胺含量的变化

为评价转鼠酪氨酸羟化酶（TH）基因的成肌细胞脑内移植对偏侧帕金森病（PD）大鼠模型纹状体区多巴胺及代谢产物含量的影响，应用6－羟多巴胺损毁SD大鼠单侧黑质制备偏侧帕金森病臣模型。模型稳定必个月后，移植转TH基因的成肌细胞（n＝24）或未转基国的成肌细胞（n＝10）于偏侧PD鼠损毁侧纹状体。移植治疗后6个月，用高效液相色谱电化学法（HPLC－ECD）检测偏侧PD鼠模型纹状体区多巴胺、3，4－二羟苯乙酸（DOPAC）以及高香草酸（HVA）含量。结果转TH基因成肌细胞植入组PD鼠纹状体区多巴胺及代谢产物含量明显增高（P＜0．01），其中多巴胺含量从治疗前平均39．20Pg／mg提高至治疗后的985．71Pg／mg，相当于正常侧纹状体的49．99％．对照组植入未转基因的成肌细胞后纹状体多巴胺及代谢产物含量无明显变化（P＞0．05）。可见转鼠TH基因的成肌细胞脑内移植能够部分改善偏侧PD鼠模型纹状体区多巴胺的缺乏，成肌细胞是PD基因治疗的合适靶细胞之一。     

抑郁症与帕金森病患者脑多巴胺转运蛋白核素显像的对照研究

目的 探讨抑郁症与帕金森病患者脑多巴胺转运蛋白核素显像的特点.方法 采用多巴胺转运蛋白显像剂(99Tcm-TRODAT-1)通过单光子发射型计算机断层显像(SPECT)成像技术,对13例抑郁症患者、17例帕金森病(PD)患者和10名正常对照进行脑多巴胺转运蛋白分布核素显像.结果 三组比较,右侧纹状体与左侧纹状体(RST/LST)比值比较,差异无统计学意义(P＞0.05),而右侧纹状体与小脑(RST/CB)和左侧纹状体与小脑(LST/CB)放射性比值的差异有统计学意义(均P＜0.01).其中对照组RST/CB和LST/CB最高(分别为3.486±0.207和3.553±0.158),其次为抑郁症组(分别为2.255±0.290和2.317±0.341),而PD组最低(分别为1.522±0.237和1.547±0.262).结论 抑郁症和PD患者的双侧纹状体及小脑的放射性比值均低,其中PD患者更显著.     

TH基因修饰细胞脑内移植治疗猴帕金森病的实验研究

目的 评价包囊化酪氨酸羟化酶（tyrosine hydroylase,TH）基因修饰的基因工程细胞脑内移植治疗帕金森病的疗效。方法 将pcDNA3/hTH质粒转染人神经母细胞瘤细胞系SYTY细胞，筛选出阳性克隆，微包囊化处理后的含有TH基因修饰细胞植入PD猴模型脑内，观察其行为、CSF中DA含量的变化，用免疫组化法检查移植细胞的存活情况。结果 （1）pcDNA3/hTH基因经亚克隆，提取纯化的质粒，经ECORI酶切后产生1.9Kb和5.5Kb的片段。转基因后的SY5Y细胞免疫细胞化学染色显示TH染色强阳性；（2）移植后PD猴症状明显改善，脑脊液中DA含量升高；（3）SABC免疫组化发现移植区存在大量TH阳／性细胞。结论 构建的TH基因工程细胞体外和体内均表达人类TH基因；微包囊化处理后的基因工程细胞在PD猴脑内存活并发挥治疗作用。     

偏侧PD猴模型黑质和纹状体GFAP表达的变化

目的探讨偏侧帕金森病（PD）猴模型黑质和纹状体胶质原纤维酸性蛋白（GFAP）表达的变化。方法向3只恒河猴经单侧颈内动脉注射1-甲基4-苯基1，2，3，6-四氢吡啶（MPTP）制备偏侧PD猴模型，应用免疫组化染色方法观察3只偏侧PD猴模型和1只正常猴黑质和纹状体GFAP表达变化。结果偏侧PD模型猴MPTP毁损侧的黑质和纹状体GFAP免疫阳性细胞数目较对侧和正常对照猴明显增加，但MPTP毁损侧对侧的黑质和纹状体GFAP免疫阳性细胞数目未发现明显变化。结论偏侧PD猴模型MPTP毁损侧黑质和纹状体GFAP的表达增加，推测星形胶质细胞可能在黑质和纹状体神经元变性和死亡过程中起一定作用。     

Therapeutic benefit of TH-engineered mesenchymal stem cells for Parkinson's disease

The present study was designed to assess the potential of marrow stromal cells (MSCs) to deliver therapeutic genes to the brain and result in biologically significant functional recovery. The tyrosine hydroxylase (TH) gene was transfected to MSCs with an adeno-associated virus (AAV) vector. MSCs expressing TH gene were transplanted into the striatum of Parkinson's disease (PD) rat. The asymmetric rotation of these models after apomorphine administration was detected every week after transplantation. Six weeks after grafting, animals were sacrificed. Some brains were sectioned to do TH immunohistochemistry. The others were used to detect the dopamine levels by high-performance liquid chromatograph and electrochemical detection (HPLC-ECD). The results showed that MSCs multiply rapidly and formed fibroblast colony-forming units in primary culture. The gene expression efficiency was about 75%. The rounds of asymmetric rotation after apomorphine administration decreased after TH-engineered MSCs were grafted. Histological examination showed that TH gene was expressed around the transplantation points. The dopamine level in the lesioned striatum of rats injected with TH-MSCs was significantly greater than that in rats treated with LacZ-MSCs (P < 0.05). All the data demonstrated that MSCs could readily be genetically engineered. Therefore, MSCs could be useful gene delivery vehicles of gene therapy for Parkinson's disease.     

Glial Cell Line-Derived Neurotrophic Factor Improves Survival of Dopaminergic Neurons in Transplants of Fetal Ventral Mesencephalic Tissue

This study was designed to determine whether or not an exogenous source of glial cell line-derived neurotrophic factor (GDNF) could be delivered continuously into the denervated/transplanted striatum and stimulate the survival, growth, and function of fetal ventral mesencephalic tissue transplants. Adult male rats with unilateral 6-hydroxydopamine lesions received transplants of fetal ventral mesencephalic tissue into the denervated striatum. Immediately thereafter, osmotic pumps [Alzet 2002, 0.5 μl/h] were attached to intracerebral cannula and either a citrate buffer alone [control] orr-methuGDNF [dissolved in sodium citrate buffer to a concentration of 0.45 μg/μl] was infused into a site ≈1.0 mm lateral to the transplant for a 2-week period; one group of lesioned animals did not receive transplants but was infused with GDNF. The effect of GDNF on tyrosine hydroxylase-positive (TH+) fiber outgrowth from transplants was variable, and image analysis revealed no significant difference between the GDNF and citrate groups. In contrast, the mean number of TH+ cells bodies in transplants infused with GDNF [2,037 ± 149,n = 8] vs citrate [663 ± 160,n = 8] was statistically significant (P < 0.001); cell counts were made in every third brain section [35 μm]. Similarly, transplants infused with GDNF showed an over-compensatory effect to amphetamine-induced rotational behavior that was significantly lower than that observed in transplanted animals receiving citrate buffer infusions. Infusions of GDNF into the denervated striatum alone had no significant effect on amphetamine-induced rotational behavior or on TH fiber morphology in the lesioned striatum. Thus, a continuous infusion of GDNF can improve the survivability of dopaminergic neurons in transplants of fetal ventral mesencephalic tissue.     

Cultured human foetal cerebral cortex, transfected with tyrosine hydroxylase cDNA, as a source of neural transplant material

Summary. Obtaining an adequate supply of foetal dopaminergic tissue to treat Parkinson's disease by neural transplantation can be difficult. In this study primary cultures of human foetal cerebral cortex cells were transfected, using cationic lipids, with a eukaryotic expression vector (pCIneo-THI) containing the cDNA for human tyrosine hydroxylase isoform I (TH). Cortical cells from human (10–14 week) foetuses were cultured for 11 days in vitro and transfected twice with pCIneo-TH1 during this time. The double transfection process resulted in 3–4% of the cells becoming TH positive. When grafted into the striatum of 6-OHDA lesioned rats the transfected foetal cerebral cortex cells reduced amphetamine-induced circling behaviour by 75%, while grafts of untransfected cells had no significant effect on turning. TH transfected foetal cerebral cortex cells may therefore be a useful alternative supply of tissue for use in neural transplants to treat Parkinson's disease. Received April 4, 2000; accepted February 5, 2001     

Gene therapy of Parkinson's disease using adeno-associated virus (AAV) vectors

Parkinson's disease (PD) is characterized by the progressive loss of the dopaminergic neurons in the substantia nigra and a severe decrease in dopamine in the striatum. A promising approach to the gene therapy of PD is intrastriatal expression of dopamine-synthesizing enzymes [tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC)]. The most appropriate gene-delivery vehicles for neurons are adeno-associated virus (AAV) vectors, which are derived from non-pathogenic virus. Therefore, TH and AADC genes were introduced into the striatum in the lesioned side using separate AAV vectors in parkinsonian rats, and the coexpression of TH and AADC resulted in better behavioral recovery compared with TH alone. Another strategy for gene therapy of PD is the protection of dopaminergic neurons in the substantia nigra using an AAV vector containing a glial cell line-derived neurotrophic factor (GDNF) gene. Combination of dopamine-supplement gene therapy and GDNF gene therapy would be a logical approach to the treatment of PD.     

GFP,TH双基因在NIH-3T3细胞及帕金森病大鼠脑内的表达

目的以绿色荧光蛋白（ＧＦＰ）作为一个标记,观察ＧＦＰ标记的ＨＴＨ１基因修饰的ＮＩＨ－３Ｔ３细胞在体外及植入脑内后的生长情况,判断ＧＦＰ基因能否作为一种新的筛选标记基因。方法构建同时表达ＧＦＰ和ＨＴＨ１双基因的多基因表达载体ＧＣ－ＧＦＰ－Ｐ－ＨＴＨ１－ＳＮ。并转染ＮＩＨ－３Ｔ３细胞,且移植入Ｐａｒｋｉｎｓｏｎ病模型大鼠纹状体内。结果用荧光显微镜、流式细胞仪、免疫组化、ｗｅｓｔｅｒｎｂｌｏｔｉｎｇ等方法均检测到ＧＦＰ、ＨＴＨ１在体外和脑内的表达。结论ＧＦＰ可作为一个筛选标记基因,可对目的基因或植入细胞的其他功能性产物的表达进行观察和检测。     

脑内移植骨髓间质干细胞治疗帕金森病模型大鼠的实验研究

目的 探讨骨髓间质干细胞(mesenchymal stem cells,MSCs)移植治疗帕金森病(parkinson's disease,PD)大鼠的可行性及可能的机制.方法 移植Brdu标记的MSCs到模型大鼠的纹状体内.术后4个月中,定期对大鼠进行旋转行为学实验测试.并分别在术后2周和4个月时进行脑内针道处及移植区免疫组化检测TH和Brdu的表达.结果 Brdu标记的MSCs移植到模型大鼠的纹状体内,术后2周时移植针道处及针道周围可见Brdu阳性外源MSCs,并有外源性细胞表达TH,术后4个月时移植针道内仍可以看到MSCs存活.MSCs移植的PD模型大鼠症状较PBS注射组行为学明显改善.结论 移植MSCs到大鼠PD模型的纹状体内能成活,且分化细胞能表达TH蛋白,大鼠PD模型行为学症状明显改善.