大鼠鞘内注射单纯疱疹病毒Ⅰ型扩增子载体介导人前脑啡肽原基因的表达及对甲醛炎性痛的镇痛效应

Intrathecal administration of HSV-I amplicon vector-mediated HPPE gene therapy of nocicepion in rats with formalin pain

目的:大鼠鞘内注射介导人前脑啡肽原基因(HPPE)单纯疱疹病毒Ⅰ型(HSV-Ⅰ)扩增子载体,观察LacZ和HPPE在脊髓神经元细胞中的共表达及对甲醛炎性痛的镇痛效应。方法:纯种雄性SD大鼠随机分为pHSVIRES-HPPE-LacZ载体组(SHPZ),pHSVIRES-LacZ空白载体组(SHZ),生理盐水组(NS),又分为分别注射SHPZ,SHZ和NS后3d,1周,2周,3周,4周,5周时观察镇痛效应组,并对1周组观察HPPE转染表达,每组6只。采用改良Yaksh法对大鼠进行鞘内置管后,将构建好的含HPPE的重组单纯疱疹病毒I型扩增子载体注入大鼠鞘内,通过X-gal染色原位检测报告基因LacZ的表达,逆转录聚合酶链式反应(RT-PCR)方法检测HPPE的表达,放射免疫法检测脊髓组织脑啡肽浓度,并观察转染含HPPE基因载体对大鼠甲醛炎性疼痛的镇痛效应。结果:pHSVIRES-HPPE-LacZ在体感染大鼠中枢神经细胞后,用X-gal染色、RT-PCR和放射免疫检测方法均证实外源脑啡肽基因能有效表达。对甲醛诱发的炎性疼痛中,疼痛加权评分(PIS)于1周,2周,3周,4周时在第1相和第2相与对照组比较有显著差异,于第5周时第2相PIS接近对照组,对甲醛的镇痛效应可被鞘内注射纳洛酮拮抗。结论:SHPZ能成功地将外源HPPE转染到脊髓神经元细胞中,使之有效表达,提示扩增子载体SHPZ是良好的慢性疼痛转基因治疗工具;HPPE的表达产物可对甲醛炎性痛产生镇痛效应。

Objective To investigate the antinociceptive effect of intrathecal administration of HSV-Ⅰ amplicon vector-mediated HPPE. Methods Sprague Dawley rats （290±30） g were randomly divided into pHSVIRES-HPPE-LacZ （SHPZ） group, pHSVIRES-LacZ （SHZ） group, and saline group （NS） , and 3 d, 1 week, 2 weeks, 3 weeks, 4 weeks, and 5 weeks group, which were anesthetized with 10% chlroral hydrate 300 -350 mg/kg. A microspinal catheter was inserted into the lumbar subarachnoid space. Rats were intrathecally delivered with recombinant HSV- Ⅰ amplicon vector SHPZ, SHZ or NS. The HPPE expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） and radioimmune assay. Formalin 50 μL （5%） was injected into the left hindpaw, pain intensity scoring （PIS） was used to assess the antinociceptive effect. Results After in vivo transferring, neurocyte demonstrated strong positive signals with X-gal immunohistochemical staining. RT-PCR and L-enkephalin radioimmune assay found that the neural cells transferred foreign gene （HPPE） had effective expression. Intrathecal delivery of SHPZ showed antinociceptive effects on formalin induced pain for 5 weeks compared with SHZ. Conclusion This amplicon virus can transfer HPPE into rat central nerve system neural cells and express efficiently, suggesting SHPZ is satisfactory treatment for gene therapy for chronic pain. Intrathecal delivery SHPZ demonstrated antinociceptive effects on formalin induced pain.