Schwann cells genetically modified to secrete human BDNF promote enhanced axonal regrowth across transected adult rat spinal cord
Schwann cells genetically modified to secrete human BDNF promote enhanced axonal regrowth across transected adult rat spinal cord
复制标题
DOI：
10.1046/j.1460-9568.1998.00071.x
复制
发表时间：
1998-02-01
影响因子：
3.4
通讯作者：
Bunge, MB
中科院分区：
文献类型：
--
作者：
Menei, P;Montero-Menei, C;Bunge, MB
将BDNF和NT-3输注到雪旺细胞（SC）移植物中，可促进在T8时横断的成年大鼠脊髓移植物中脑干神经元的再生（Xu等，1995b）。在这里，我们比较了正常的SCs和基因修饰的分泌人BDNF的SCs，在横断部位远端的脊髓中作为5毫米长的trail移植，也沉积在横断部位，因为它们能够刺激损伤后的脊髓上轴突再生。SCs被编码人类preproBDNF cDNA的复制缺陷逆转录病毒载体pL(hBDNF)RNL感染。BDNF的分泌量（ELISA检测）分别为每10(6)个细胞23和5 ng/24 h。分泌的BDNF生物活性经视网膜神经节细胞生物测定证实。在T8时横切成年大鼠脊髓。使用赫斯特预先标记的SCs表明，痕迹可以维持一个月。对照组未移植SCs。移植1个月后，SC尾迹中出现轴突。与正常SC相比，在感染SC中观察到更多的5- ht阳性纤维和一些dph阳性纤维。当Fast Blue在横断部位下方5mm处注射时，在脑干中可以发现多达135个逆行标记的神经元，主要位于网状核和中缝核（正常SCs多达22个，主要位于前庭核）。下丘脑腹侧标记了大量神经元（正常SCs， 0）。此外，注射Fast Blue后，平均138个标记细胞存在于背根神经节（正常SCs， 46个）和脊髓（39个vs. 32个）横截面的吻侧，未移植SCs时未见标记脊髓神经元的吻侧。因此，分泌BDNF量增加的SCs移植改善了胸脊髓横断部位的再生反应。此外，受感染的SCs所观察到的增强再生可能是特异性的，因为最大的反应来自已知表达trkB的神经元。
The infusion of BDNF and NT-3 into Schwann cell (SC) grafts promotes regeneration of brainstem neurones into the grafts placed in adult rat spinal cord transected at T8 (Xu at al., 1995b). Here, we compared normal SCs with SCs genetically modified to secrete human BDNF, grafted as trails 5 mm long in the cord distal to a transection site and also deposited in the transection site, for their ability to stimulate supraspinal axonal regeneration beyond the injury. SCs were infected with the replication-deficient retroviral vector pL(hBDNF)RNL encoding the human preproBDNF cDNA. The amounts of BDNF secreted (as detected by ELISA) were 23 and 5 ng/24 h per 10(6) cells for infected and normal SCs, respectively. Biological activity of the secreted BDNF was confirmed by retinal ganglion cell bioassay. The adult rat spinal cord was transected at T8. The use of Hoechst prelabelled SCs demonstrated that trails were maintained for a month. In controls, no SCs were grafted. One month after grafting, axons were present in SC trails. More 5-HT-positive and some DPH-positive fibres were observed in the infected vs. normal SC trails. When Fast Blue was injected 5 mm below the transection site (at the end of the trail), as many as 135 retrogradely labelled neurones could be found in the brainstem, mostly in the reticular and raphe nuclei (normal SCs, up to 22, mostly in vestibular nuclei). Numerous neurones were labelled in the ventral hypothalamus (normal SCs, 0). Also, following Fast Blue injection, a mean of 138 labelled cells was present in dorsal root ganglia (normal SCs, 46) and spinal cord (39 vs. 32) rostral to the transection, No labelled spinal neurones rostral to the transection were seen when SCs were not transplanted. Thus, the transplantation of SCs secreting increased amounts of BDNF improved the regenerative response across a transection site in the thoracic cord. Moreover, the enhanced regeneration observed with infected SCs may be specific as the largest response was from neurones known to express trkB.