Effect of α-synuclein on the promoter activity of tyrosine hydroxylase gene

Objective To approach the associated mechanism by which α-synuclein （α-Syn） might regulate the metabolism of dopamine. Methods A DNA fragment, located at --495 to ＋25 of the human tyrosine hydroxylase （TH） gene, was amplified by PCR and inserted into the pGL3-Basic luciferase reporter vector. The recombinant plasmid pGL3-THprom was transfected into a dopammergic cell line MES23.5 or a α-Syn over-expressed MES23.5 （named MES23.5/hα-Syn^＋）. The promoter activity was detected by the Dual Luciferase Assay System. Results The luciferase activities in the MES23.5 cells transfected with pGl.,3-Basic, pGL3-THprom, and pGL3-Control vectors were 5.60±0.67, 26.80±4.11, and 32.90±4.75, respectively. On the other hand, the luciferase activity of pGL3-THprom in the MES23.5 （26.80±4.11） was significantly higher than that in the MES23.5/hα-Syn^＋（14.40±0.61） （P〈0.01）. Conclusion These results indicate that the -495 to ＋25 region in the TH gene possesses promoter activity for controlling the gene expression, and that α-Syn may negatively regulate the metabolism of dopamine by affecting the function of TH promoter as a trans-acting factor.

Cloning and Expression Profile of Deoxyhypusine Snyhtase Gene and Deoxyhypusine Hydroxylase Gene in Silkworm, Bombyx mori

Deoxyhypusine snyhtase （DHS） and deoxyhypusine hydroxylase （DOHH） are the two enzymes that catalyze the synthesis of hypusine within eukaryotic initiation factor 5A （eIF5A）. Synthesis of hypusine is essential for the function of eIF5A in eukaryotic cell proliferation and survival. Here we described the cloning and expression of two full-length cDNAs, encoding respectively DHS-like protein and DOHH-like protein from Bombyx mori by using the methods of bioinformatics, RACE, and RT-PCR technology, named as BmDHS and BmDOHH. Sequencing results indicate that they are 1 311 and 1 874 bp in length including complete open reading frame （ORF） 1 116 and 915 bp, which encode 371 amino acids （molecular weight is about 41.11 kD and isoelectric point is 5.84） and 304 amino acids （molecular weight is about 34.30 kD and isoelectric point is 4.86）, respectively. BmDHS contains only 1 exon, and BmDOHH contains 4 exons and 3 introns. The deduced amino acid sequence of BmDHS contains a deoxyhypusine synthase domain from 47 to 361 amino acid residues, and the deduced amino acid sequence of BmDOHH contains 6 E-Z type HEAT repeat domains （23-52, 54-83, 87-116, 177-206, 208-237, and 241- 270）. Compared to DHS and DOHH amino acid sequences from other species, such as Homo sapiens and Drosophila melanogaster, both silkworm DHS protein and DOHH protein have more than 55% identity. The conservative regions are very similar with each other. The phylogenetic tree analysis indicated that not only DHS but also DOHH from different species has genus-specific features. The expressions of BmDHS and BmDOHH are no tissue and stage specific in our tested samples.

Generation of tryptophan hydroxylase 2 gene knockout pigs by CRISPR/Cas9-mediated gene targeting

Unbalanced brain serotonin(5-HT) levels have implications in various behavioral abnormalities and neuropsychiatric disorders. The biosynthesis of neuronal 5-HT is regulated by the rate-limiting enzyme, tryptophan hydroxylase-2(TPH2). In the present study, the clustered regularly interspaced short palindromic repeat(CRISPR)/CRISPR-associated(Cas) system was used to target the Tph2 gene in Bama mini pig fetal fibroblasts. It was found that CRISPR/Cas9 targeting efficiency could be as high as 61.5%, and the biallelic mutation efficiency reached at38.5%. The biallelic modified colonies were used as donors for somatic cell nuclear transfer(SCNT) and 10 Tph2 targeted piglets were successfully generated. These Tph2 KO piglets were viable and appeared normal at the birth.However, their central 5-HT levels were dramatically reduced, and their survival and growth rates were impaired before weaning. These Tph2 KO pigs are valuable large-animal models for studies of 5-HT deficiency induced behavior abnomality.

Cloning of TaCYP707A1 Gene that Encodes ABA 8′-Hydroxylase in Common Wheat (Triticum aestivum L.)

The plant hormone abscisic acid （ABA） regulates many important physiological and developmental processes in plants. The objective of this study was to clone the ABA 8′-hydroxylase gene in common wheat. In the present study, we used the eDNA sequence of barley HvCYP707A1 gene （GenBank accession no. AB239299） as a probe for BLAST search against the common wheat （Triticum aestivum L.） EST database in GenBank. All wheat ESTs sharing high similarity with the reference gene were subjected to contig assembly. Primers were designed based on the constructed contigs to clone the wheat CYP707A1 gene, designated as TaCYP707A1. The genomic DNA sequence of TaCYPTO7A1 gene comprised five exons and four introns, with a size of 2225 bp. The corresponding cDNA sequence of TaCYP707A1 was 1737 bp, containing an open reading frame （ORF） of 1431 bp, a 42-bp 5′-untranslated region （UTR） and a 264-bp 3′UTR, with 94.9% of identical sequences to HvCYP707A1 gene （AB239299）. The neighbor joining tree indicated that the deduced amino acid sequences of TaCYP707A1 gene was highly similar to those of barley and rice. The TaCYP707A1 gene was located on chromosome 6BL using a set of Chinese Spring nullisomic-tetrasomic lines and ditelosomic line 6BS. These results will be of high importance in understanding of molecular mechanism of ABA catabolism.

TWO NOVEL MUTATIONS IN PHENYLALANINE HYDROXYLASE GENE AND IN VITRO EXPRESSION ANALYSIS ON MUTATION ARG252GLN

We report novel mutations in exon 7 of human phenylalanine hydroxylase (PAH) gene of phenylketonuria (PKU ) in southern Chinese, analysed by using PCR-DGGE (denaturing gradient gel electrophoresis ), solid phase DNA sequencing and Ih vliro expression. One of the 2 novel mutations, IVS6nt1, is an intron-exon Junctional mutation which results a splicing defect in mRNA. Arg252Gln is another novel mutation with residual PAH activity only 24 % compared to wild type in in vitro mutagenesis and expression in Cos-1 cell. Other 3 known mutations and polymorphism including Arg241Cys, Arg243Gln and Val245Val(GTG to GTA) together with these novel mutations composed the mutatlonal profile of exon 7 in the PAH gene of PKUs in this populations.

MUTATIONS IDENTIFIED IN EXON 7 OFPHENYLALANINE HYDROXYLASE GENE IN CHINESE

Exon 7 of the l’henylalan1ne hydroxylase (PAH) gene was analyzed in 15 chlldren affected wlth classicphenylketonL1rla (PKU) from northern Chlna by uslng PCRxsingle strand conformation polymorphism(PCR-SSCP) technique and DNA direct sequencing. Six missense mutatlons (l. e. R2413Q. R 241H, G247V,1,2 19H, F2541;lnd G257V )and one silent rnutatlon (V245v ) were identified. The latter three missense mu-tations were demonstrated as novel mltations in comparison with the PAH mutation database. one missense mt1tation (R241 H) was flrst dowumeTlted in Chinese. our results showed populatlon ancl reglon tllffer-ences in the PAH mutation clistribution. and suggest that there is more thfln one founding population forPKU in China. The fincling of novel mutations will enhence the molecular diagnosis of PKU.

Tyrosine hydroxylase gene transfections to different sites of striatum in the rat model of Parkinson’s disease

The use of gene therapy has been intensively studied as a potential method to treat Parkinson’s disease (PD) and other degenerative brain diseases. However, the effects of experimental measures and approaches on the outcome of gene delivery or on the physiological state of target tissues have not been analyzed as much and systematically. Therefore, we have infused adenovirus vectors expressing either a therapeutic tyrosine hydroxylase (TH) gene or a lacZ reporter gene into striatum in a rat model of PD. The experimental procedures were tested using the Ad lacZ vector in order to optimize concentrations, volumes, infusion speeds and transfection times. The expression of Ad lacZ vector was lower and declined earlier in the lesioned than unlesioned striatum suggesting that the lesion affects on the transfection efficiency and outcome of gene transfection. The effect of three different approaches of Ad TH vector transfection was compared: 1) the delivery of Ad TH gene vector alone into one single site of striatum, 2) the delivery of Ad TH gene vector alone into multiple sites of striatum, and 3) the delivery of Ad TH gene vector into one site of striatum followed by a continuous infusion of tetrahydrobiopterin (BH4) cofactor with a mini pump. There was a small and transient unsignificant decrease in the turning behavior when the Ad TH vector was delivered into one site of the striatum. Simultaneous infusion into several sites or together with BH4 cofactor did not improve more the effect of gene delivery. Thus, although the effects were unsignificant, the Ad TH transfection seemed to decrease the turning behavior in the rat model of PD and the optimal effect was seen at some specific doses and time points. Furthermore, the outcome of gene therapy could depend in addition to the amount and efficacy of gene vectors also on the physiological state and experimental strategies.

日本落叶松LkF3H2基因克隆及调控类黄酮代谢功能研究

【目的】日本落叶松黄烷酮3-羟化酶(flavanone 3-hydroxylase 2,LkF3H2)基因在类黄酮生物合成过程中发挥着重要的调控功能。探究LkF3H2基因在日本落叶松中发挥的具体功能和植物类黄酮生物代谢过程。【方法】根据实验室前期转录组数据克隆日本落叶松LkF3H2基因并进行生物信息学分析及组织表达分析。随后将该基因转化烟草进行转基因烟草组织表达分析及类黄酮含量测定,以探究基因表达量与类黄酮含量之间的关系。【结果】LkF3H2基因cDNA序列长度为1074 bp,其蛋白编码358个氨基酸,分子式C_(1785)H_(2807)N_(481)O_(541)S_(18),分子量为40.24 kD,该蛋白是不稳定的亲水性蛋白且不含信号肽;同时系统进化分析得出日本落叶松LkF3H2与火炬松、辐射松、白云杉和欧洲云杉F3H亲缘关系较近并且该蛋白含有保守结构域2OG-Fe(Ⅱ)oxygenase superfamily,属于2-酮戊二酸依赖性双加氧家族。另外组织表达分析显示LkF3H2基因在一月龄日本落叶松幼苗叶中表达量最高,在一年生日本落叶松幼苗茎中表达量最高,并且在转基因烟草叶中也显示了最高的表达量。值得一提的是,转基因烟草叶中的类黄酮含量也是最高的,其次为茎和根,转基因烟草中类黄酮含量与LkF3H2基因表达量呈正相关关系。【结论】日本落叶松LkF3H2基因属于2-酮戊二酸依赖性双加氧家族并且在类黄酮生物合成过程中发挥着重要功能。

Molecular Cloning and Expression of Carotenogenic Genes in Yellowish and Mutant Whitish Loquat (Eriobotrya japonica) Fruits

ObjectiveThe study aimed to explore the factors regulating carotenoid accumulation in flesh color. MethodA loquat mutation （red-or orange-fleshed plant emerged a bud mutation of white-flesh in trunk） was used as material; HPLC analysis of β-carotene content was conducted. ResultThe β-carotene concentration in the flesh of wild and mutant types was 60.9 and 4.6 μg/g fresh weight, respectively. According to the conserved regions of genes from rose family genome, carotenogenic gene fragments in wild and mutant types were obtained. No nucleotide variation of the carotenogenic gene fragments was observed between wild and mutant genome. Real-time quantitative polymerase chain reaction （Q-PCR） was compared and one carotenogenic gene, β-ring hydroxylase （HYB） were considerably suppressed in mature mutant loquat fruits compared with that in wild. The other six carotenogenic genes were also expressed but the expression patterns appeared to be not correlated with the amount of β-carotene concentration in wild loquat flesh. ConclusionThe mutant whitish loquat lacks the ability to synthesize β-carotene because of the transcriptional down-regulation of carotenogenic gene HYB.

CYP17A1基因突变致先天性肾上腺皮质增生症一例报道并文献复习

17α-羟化酶缺乏症(17-OHD)是先天性肾上腺皮质增生症(CAH)中的一种罕见类型,约占CAH的1%,其患病率为1∶50000。本文报道了1例疑似17-OHD患者,通过外显子测序鉴定了1个类固醇生成酶基因CYP17A1的基因突变,结合临床表现、体格检查、肾上腺和性腺功能检查等,最终将其明确诊断为CAH并给予规范治疗。故结合该病例,本文回顾总结了17-OHD的鉴别和诊断,以期提高临床对该病的认识,促进临床对17-OHD的规范诊治,为17-OHD的诊断和治疗提供更多的参考资料。

一株苯酚降解菌(Alcaligenes faecalis BC2001)的PCR检测及其苯酚降解特性研究

根据苯酚羟化酶基因高度保守序列设计一对该基因的特异引物。采用该特异引物从粪产碱菌BC2001总DNA中扩增一条大小为684 bp的片段。将该DNA片段进行序列分析,发现其与Proteobacterium L-18菌(登录号为:AY346142)的基因序列的同源性为97%。另降解试验表明BC2001菌在pH=6时(质量浓度为500mg.L-1)其生长最佳,而在苯酚质量浓度为300 mg.L-1时也是菌株具降解能力的有效例子。

三种花色黄芩中F3′5′H基因的克隆及表达分析

类黄酮3′,5′-羟化酶(flavonoid 3′,5′-hydroxylase,F3′5′H)是花青素合成途径中催化形成蓝色飞燕草素的关键酶。本研究通过RT-PCR方法,从蓝紫花、玫红花、白花黄芩中克隆得到F3′5′H基因的全长序列,分别命名为SbF3′5′H-b、SbF3′5′H-r、SbF3′5′H-w。经序列比对,SbF3′5′H-r基因较SbF3′5′H-b/w缺失7 bp,导致蛋白翻译提前终止。生物信息学分析显示,三个SbF3′5′H蛋白均属于细胞色素P450家族,定位在内质网。SbF3′5′H-B/W蛋白具有典型的CYP450保守序列,包括富含脯氨酸基序“LPPGP”、底物识别位点SRS1~6、折叠锁定基序“E××R”、血红素结合基序“PFGAGRRICAG”及预测的羟化活性位点CR1和CR2。而SbF3′5′H-R蛋白由于序列缺失影响二级、三级结构,并导致CYP450结构域不完整,C端缺少多个维持酶活性的保守基序。基于F3′5′H蛋白序列的系统进化分析结果显示,黄芩与同为唇形科的丹参、一串红等亲缘关系最近,聚在一个分支,与单子叶植物亲缘关系较远。基因表达分析结果显示,SbF3′5′H在白花中整体表达最高,其次是蓝紫花,玫红花中整体表达最低;不同花发育阶段比较,SbF3′5′H基因均呈现出先升高后降低的趋势,在中蕾期表达量最高,其次是幼蕾期,盛花期表达量最低,蓝紫和白花黄芩不同花发育阶段间差异显著或极显著。本研究结果可为进一步研究不同花色黄芩中SbF3′5′H基因的功能差异、揭示黄芩花色变异的分子机理奠定理论基础。

滇龙胆草中香叶醇10-羟化酶基因的克隆、蛋白结构及表达分析

本研究基于滇龙胆草转录组数据分析,使用RT-PCR技术克隆获得两条香叶醇10-羟化酶基因,命名为GrG10H1和GrG10H2。使用在线软件对其进行了生物信息学分析,两条基因全长分别为1548 bp、1482 bp。系统进化分析显示该基因与细胞色素P450家族中CYP76B亚家族亲缘关系最近。通过对该蛋白进行三维结构预测、同源模建和分子对接,分析了GrG10H蛋白活性口袋中可能参与催化功能发挥的关键氨基酸残基。荧光定量PCR表明GrG10H1基因在叶中表达水平最高,茎次之,根最低。而GrG10H2基因在根和叶中表达水平较高,在茎中几乎不表达。本研究还建立了能够生产龙胆苦苷的愈伤组织细胞培养体系,为进一步解析龙胆苦苷生物合成机制奠定了基础。

一个类黄酮3'-羟化酶参与多星韭花色素生物合成的功能解析

类黄酮3'-羟化酶(F3'H)在花色素苷生物合成过程中起关键作用。明确多星韭F3'H在花色素苷生物合成中的功能,将为多星韭花色形成及改良研究提供基因资源。基于转录组数据从多星韭花朵中克隆获得AwF3'H,并对其进行生物信息学分析,利用Real time PCR对AwF3'H1的表达模式进行分析,并利用蘸花法将AwF3'H转入拟南芥中,同时对转基因植株进行表型观察及花色素苷检测分析。结果表明,Aw F3'H的ORF全长为1545 bp,编码514个氨基酸,属于细胞色素P450家族成员,与洋葱AcF3'H的亲缘关系最近;在所检测组织均有表达,但在雄蕊中表达最高,根中表达最低;与野生型拟南芥相比,转AwF3'H拟南芥T2代幼苗子叶及下胚轴颜色明显加深,矢车菊素与天竺葵素类花色苷积累量显著增加。表明AwF3'H具有类黄酮3'-羟化酶的功能。

TH基因变异致多巴反应性肌张力障碍二例

例1女性,8岁,主因独立行走不能6年余,于2011年8月10日至我院神经内科门诊就诊。患儿于出生后约15月龄时(2004年10月)受凉后发热(约39℃)而出现肢体活动差,表现为四肢活动减少,独自站立不能,症状呈进行性加重,尤以受凉、上呼吸道感染后症状明显加重。2岁时仍无法独立行走,需他人扶行,并出现四肢关节挛缩,症状有日间波动性,晨轻暮重。曾于外院就诊,具体检查和诊断不详,未予治疗。家属诉患儿出生史及1岁以内语言、运动等生长发育史均正常;父母非近亲婚配,否认家族中有类似疾病病史。

基于生物信息学分析骨肉瘤的关键基因和qRT-PCR实验验证

目的利用生物信息学方法筛选出与骨肉瘤(osteosarcoma,OS)相关的关键基因,以作为OS的潜在诊断标志物和新治疗靶点。方法从基因表达综合(Gene Expression Omnibus,GEO)数据库中检索下载2个符合本研究的OS相关数据集(GSE16088和GSE42572),共包括21例OS组织样本和14例正常骨组织样本。对数据集进行矫正分析鉴定出差异表达基因(differentially expressed genes,DEGs)。通过加权基因共表达网络分析方法(weighted gene co-expression network analysis,WGCNA)与DEGs筛选出交集基因。对交集基因进行疾病本体论(Disease Ontology,DO)、基因本体论(Gene Ontology,GO)、京都基因与基因组百科全书分析(Kyoto Encyclopedia of Genes and Genomes,KEGG)和蛋白互作(protein-protein interaction,PPI)网络分析。采用受试者工作特征(receiver operating characteristic,ROC)曲线评估该PPI网络degree排名前10位的Hubbe基因的表达水平对OS患者的诊断效能,并以另一个OS数据集GSE19276对Hubbe基因进行验证筛选出关键基因。分析关键基因与浸润性免疫细胞的相关性。收集2020年9月1日至2022年6月30日于广西中医药大学第一附属医院住院手术的4例OS患者的OS组织及其癌旁组织,采用实时荧光定量聚合酶链式反应(real-time quantitative polymerase chain reaction,qRT-PCR)对关键基因进行实验验证。结果在OS组织与正常骨组织中共筛选出687个DEGs(上调基因523个和下调基因164个)。WGCNA关键模块基因2338个。DEGs与WGCNA关键模块基因共有交集基因545个。DO富集分析结果表明,DEGs与WGCNA结果的交集基因主要与泌尿系统癌症、肾癌、生殖细胞癌、肌肉骨骼系统癌症和胚胎癌等癌症相关。GO富集结果表明,交集基因主要参与骨化的形成、细胞外基质组织和生物矿物组织发育等生物学过程。KEGG通路富集在磷脂酰肌醇3激酶(phosphatidylinositide 3-kinase,PI3K)/蛋白激酶B(protein kinase B,PKB,又名Akt)信号通路、过氧化物酶体增殖物激活受体(peroxisome proliferators-activated receptor,PPAR)信号通路及流体剪切应力和动脉粥样硬化等信号通路上。PPI网络分析中degree排名前10位的Hubbe基因为磷脂酰肌醇4,5-二磷酸3-激酶催化亚基α(phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha,PIK3CA)、脯氨酰4-羟化酶亚单位α1(prolyl 4-hydroxylase subunit alpha 1,P4HA1)、整合素αⅤ(integrin alphaⅤ,ITGAⅤ)、组蛋白去乙酰化酶2(histone deacetylase 2,HDAC2)、连环蛋白β1(catenin beta 1,CTNNB1)、Ⅲ型胶原蛋白α1(collagen typeⅢalpha 1,COL3A1)、Ⅰ型胶原蛋白α2(collagen typeⅠalpha 2,COL1A2)、转导蛋白β样1X相关蛋白1(transducin beta-like 1X-related protein 1,TBL1XR1)、小核核糖核蛋白多肽G(small nuclear ribonucleoprotein polypeptide G,SNRPG)和Ras相关核蛋白(Ras-related nuclear protein,RAN)。以数据集GSE19276绘制ROC曲线验证Hubbe基因表明,P4HA1和ITGAV的准确度较高(均AUC>0.8且P<0.05)。qRT-PCR实验结果显示,P4HA1和ITGAV mRNA在OS组织中高表达(均P<0.01)。结论P4HA1和ITGAV是OS的潜在生物标志物和治疗靶点。

Cloning and Functional Analysis of HDR Gene from Ginkgo biloba L

[Objective] The aims were to obtain cloning of HDR gene from Ginkgo biloba.and study its function.[Method] The coding sequence of HDR gene was cloned from G.biloba by reversed transcription polymerase chain reaction,which was designated as GbHDR （GenBank accession No.：DQ364231）.The cDNA full-length of GbHDR is 1 827 bp containing a 1 425-bp open reading frame （ORF） encoding a 474-amino-acid polypeptide and constructed into the prokaryotic expression vector pTrcGbHDR.The β-carotene biosynthetic pathway in E.coli strain XL1-Blue was reconstructed by transforming with pAC-BETA.This engineered XL1-Blue was transformed with pTrcGbHDR.[Result] A 1 441 bp GbHDR was obtained containing a 1 425-bp ORF encoding a 474-amino-acid residues of protein,the predicted molecular weight was 53.2 kD,and predicted isoelectric point was 5.76.Functional complementation assay indicated that GbHDR could promote theβ-carotene accumulation in engineered XL1-Blue harboring pTrcGbHDR and pAC-BETA,and as a result,the engineered bacteria showed the brightly orange given by β-carotene.This suggested that GbHDR had the typical function of known HDR genes.[Conclusion] A engineered bacteria of E.coli which could highly accumulate β-carotene was obtained,which will provide candidate genes and targets for realizing β-carotene metabolic engineering.

红芪HpC4H基因的克隆及其铁盐干预下的表达分析

肉桂酸-4-羟化酶(Cinnamate-4-hydroxylase,C4H)在调节植物生长发育方面具有重要的作用。为探究红芪(Hedysarum polybotrys Hand.-Mazz.)黄酮类成分合成的分子调节机制,本研究以红芪幼苗为材料,通过RACE技术,克隆HpC4H基因,并进行生物信息学分析和表达模式分析。结果显示:HpC4H基因全长为1634 bp,编码477个氨基酸,蛋白分子量为54.94 kD,不含有信号肽和跨膜结构区。亚细胞定位预测显示,该蛋白定位于内质网中,具有C4H保守功能区并属于细胞色素P450超基因家族。序列分析发现,HpC4H氨基酸序列与柠条锦鸡儿(Caragana korshinskii Kom.)的相似性高达92.84%。qRT-PCR结果表明,HpC4H基因在红芪不同组织中的表达模式为:根>茎>叶,同时,该基因的表达量在不同浓度铁盐干预下有上调趋势,推测铁盐可能在调控红芪HpC4H基因表达中发挥一定作用,且低浓度铁盐溶液作用显著。

4例酪氨酸羟化酶基因突变致多巴胺反应性肌张力障碍分析

目的:提高临床医师对酪氨酸羟化酶基因(TH)突变致多巴胺反应性肌张力障碍的认识。方法:采用回顾性研究方法,分析我院2019年8月至2021年1月诊治的4例TH突变致多巴胺反应性肌张力障碍患儿的临床表现、治疗随访情况及基因特征。结果:4例患儿均来自汉族,非亲缘关系,不同家系;男3例,女1例;3~6月龄起病,均以运动发育落后起病,伴有面部表情及自主活动减少、情绪淡漠、不规则低热、鼻腔分泌物增多、眼睑下垂,动眼危象、流涎等表现,部分有晨轻暮重特点。4例患儿均给予口服多巴丝肼片治疗,临床症状均有改善。4例患儿共发现6种突变,均为复合杂合突变,其中c.755T>C突变未见相关文献报道。结论:TH突变致多巴胺反应性肌张力障碍,多于1岁内起病,以肌张力异常及运动发育落后为主要症状,多巴丝肼治疗有效,早期发现并规范用药能取得较好临床效果。

Inducing agent tamoxifen of CreER^(T2) to reduce the side effects of gene therapy for Parkinson’s disease

BACKGROUND：Gene therapy for Parkinson＇s disease is being explored as an effective strategy to restore and protect the function of neuronal cells in the substantia nigra. Regulation of gene expression is necessary for gene therapy to avoid adverse effects due to excessive synthesis of transgene products.OBJECTIVE：Here we developed recombinant adeno-associated virus （AAV） as a viral vector-mediated gene regulation system based on Cre recombinase fused to the mutated ligand-binding domain of the estrogen receptor （CreERT2） ＋ inducing agent tamoxifen. Inducible Cre recombinase was used to reduce tyrosine hydroxylase gene expression and to prevent the excessive increase in dopamine.DESIGN, TIME AND SETTING：A genetic engineering in vitro comparative study and randomized controlled animal experiment. This study was conducted at the Gene Therapy Center, Jichi Medical School, Japan from June 2002 to June 2004.METHODS：To construct a recombinant AAV vector carrying a dopamine synthase gene. The tyrosine hydroxylase gene was inserted using a IoxP fragment that could be regulated by Cre recombinase. The recombinant AAV vector carrying the CreERT2 gene was co-transduced with HEK293 cells and the corpus striatum in a rat model of Parkinson＇s disease, with inducing agent tamoxifen to regulate gene expression.MAIN OUTCOME MEASURES：The levels of dopamine and aromatic L-amino acid decarboxylase （AADC） activity were detected in HEK293 cell medium and in the corpus striatum in a rat model of Parkinson＇s disease using high-performance liquid chromatography. Immunofluorescence double staining was used to observe tyrosine hydroxylase and Cre or AADC co-expression in HEK293 cell medium. Immunohistochemical staining was employed to observe tyrosine hydroxylase and AADC expression and behavioral changes were measured in Parkinson＇s rats.RESULTS：Transfected AAV-CreERT2 and AAV expressing dopamine synthesis enzymes could increase the synthesis of dopamine in HEK293 medium and Parkinson＇s rat striatum （P 〈 0.01） and improve the rotational behavior of Parkinson＇s rats. While tamoxifen markedly reduced overproduction of dopamine caused by cotransfection of viral vectors （P 〈 0.01）, but did not affect the expression and activity of AADC.CONCLUSION：The application of AAV vector-encoded tyrosine hydroxylase gene under the gene regulation system of Cre-ERT2〉, after tamoxifen treatment, can effectively control the generation of genetically modified products to reduce the production of excessive dopamine in vivo and in vitro. Therefore, this method can increase the safety of gene therapy.