甲状腺激素诱导的神经干细胞移植对慢性实验性变态反应性脑脊髓炎的神经保护作用

目的探讨甲状腺激素诱导的神经干细胞(NSCs)是否比单纯NSCs移植对慢性实验性变态反应性脑脊髓炎(EAE)有更好的神经保护作用。方法体外培养新生大鼠NSCs和三碘甲腺原氨酸(T3)诱导的NSCs(T3/NSCs),诱导其分化7d后,免疫细胞化学或免疫荧光染色分别检测半乳糖脑苷脂阳性(Gal C+)和GFAP阳性(GFAP+)细胞。用豚鼠脊髓匀浆诱导慢性EAE大鼠模型。在免疫后10d,脑立体定位仪分别移植T3/NSCs、NSCs和生理盐水入EAE大鼠侧脑室,T3/NSCs和NSCs移植前用5-溴脱氧尿嘧啶核苷(Brd U)标记。实验分为T3/NSCs组、NSCs组和对照组,每组10只。每天对大鼠临床症状评分评估神经功能。大鼠免疫60d后处死,HE和LFB染色分别观察脑的炎症侵润和脱髓鞘;免疫荧光双标染色检测脑的Gal C+/Brd U+和GFAP+/Brd U+比例;RT-PCR法检测脑组织血小板源性生长因子α受体(PDGFαR)、Gal C和髓鞘碱性蛋白(MBP)mRNA的表达。结果 T3/NSCs体外分化为Gal C+和GFAP+细胞的比例分别高于和低于NSCs的分化。T3/NSCs组和NSCs组神经功能恢复较对照组好。T3/NSCs组较NSCs组更明显改善脑的炎症侵润和脱髓鞘,其脑内Gal C+/Brd U+及GFAP+/Brd U+的比例分别高于和低于NSCs组,脑组织的PDGFαR、Gal C和MBP mRNA的表达也较NSCs组高。结论 T3/NSCs比NSCs对EAE有更好的神经保护作用。

Neuroprotective effect of grafting thyroid hormone-induced neural stem cells on chronic experimental allergic encephalomyelitis

Objective To explore whether transplantation of neural stem cells induced by thyroid hormone (T3) provides a better neuroprotective effect than native NSCs after chronic experimental allergic encephalomyelitis. Methods Neural stem cells (NSCs) and T3-induced NSCs of neonatal rat were cultured in vitro. After 7 days they were induced to differentiate, immunohistochemistry or immunofluorescence staining were used to detect GalC+ and GFAP+ cells respectively. Chronic EAE rat models were induced by Guinea pig spinal cord homogenate, fo11owed by infusion of T3/NSCs, NSCs (T3/NSCs and NSCs were labeled with 5-bromo-2’-deoxyuridine (BrdU) and saline (T3/NSCs, NSCs and control groups，respectively) at 10 days after EAE immunization, and each group had 10 rats. Clinical scores for every day were performed to evaluate neuro1ogica1 function. All rats were sacrificed at 60d after EAE immunization. HE and LFB staining was used to observe inflammatory infiltrates and demyelination in brain respectively. Immunofluorescent double staining was used to test the ratio of GalC⁺/BrdU⁺ and GFAP⁺/BrdU⁺in brain. RT-PCR assay was used to identify the expression of mRNA for PDGFαR, GalC and MBP of brain tissue. Results The ratio of GalC⁺ or GFAP⁺ cells of T3/NSCs was respectively higher or lower than that of NSCs in vitro. Significant recovery of neuro1ogica1 function was found in T3/NSCs and NSCs groups compared with control group. Improvement of inflammatory infiltrates and demyelination in T3/NSCs groups was stronger than that in NSCs groups. In brain, the ratio of GalC+/BrdU⁺ or GFAP⁺/BrdU⁺ in T3/NSCs group was respectively higher or lower than that in NSCs group. And the expression of mRNA for PDGFαR, GalC and MBP of brain tissue in T3/NSCs groups was stronger than in NSCs groups. Conclusion The results demonstrate that grafting T3-induced NSCs provides better neuroprotection for EAE than grafting NSCs alone.