Tsukamoto Yasuhiro, Yamamoto Tatsuro, Okado Haruo, Nibu Ken-ichi, Terashima Toshio
Department of Anatomy and Developmental Neurobiology, Kobe University Graduate School of Medicine, Kobe, Japan.
Arch Histol Cytol. 2003 Aug;66(3):209-20. doi: 10.1679/aohc.66.209.
The present study tested whether a gene-transfer based upon the retrograde axonal transport of the lacZ adenovirus is effective in the spinal descending tracts of the adult mouse. A small volume of a replication-defective recombinant adenovirus encoding E. coli beta-galactosidase was injected into the upper lumbar cord, and, seven days later, the mice were transcardially perfused by a fixative solution. X-gal staining of coronal or sagittal sections of the spinal cord and the brain revealed that many sites of origin for rubrospinal, vestibulospinal, and reticulospinal tracts were retrogradely labeled, whereas few of the corticospinal tract neurons were retrogradely labeled. Ependymal cells surrounding the central canal of the spinal cord, which were located far from the injection site, showed a high expression of beta-galactosidase activity. Motoneurons around the injection site were strongly stained by X-gal staining, and their axons in the ventral root were anterogradely labeled. Afferent fibers in the dorsal root were labeled by the transganglionic transport of beta-galactosidase. To examine the efficacy of the uptake and retrograde transport of HRP and adenovirus, we injected a mixed solution of 10% HRP and recombinant adenovirus. The number of HRP-labeled corticospinal neurons overwhelmed the number of X-gal stained ones, while the numbers of HRP-labeled rubrospinal and subcoeruleus-spinal neurons were smaller in comparison with the numbers of beta-galactosidase-positive counterparts. The present study revealed that the origins for the spinal descending tracts except for corticospinal neurons could be efficiently gene-transferred by the retrograde infection of a recombinant adenovirus. Such a difference in efficacy of retrograde infection among the spinal descending tracts is practically important when an adenovirus-mediated gene transfer is designed to treat certain neurological diseases affecting the spinal descending tracts.
本研究检测了基于lacZ腺病毒逆行轴突运输的基因转移在成年小鼠脊髓下行传导束中是否有效。将少量编码大肠杆菌β-半乳糖苷酶的复制缺陷型重组腺病毒注入上腰段脊髓，7天后，经心脏灌注固定液处死小鼠。对脊髓和脑的冠状或矢状切片进行X-gal染色，结果显示，红核脊髓束、前庭脊髓束和网状脊髓束的许多起始部位被逆行标记，而皮质脊髓束神经元很少被逆行标记。远离注射部位的脊髓中央管周围的室管膜细胞显示出高β-半乳糖苷酶活性表达。注射部位周围的运动神经元被X-gal染色强烈染色，其在腹根中的轴突被顺行标记。背根中的传入纤维通过β-半乳糖苷酶的跨神经节运输被标记。为了检测HRP和腺病毒摄取及逆行运输的效果，我们注射了10%HRP和重组腺病毒的混合溶液。HRP标记的皮质脊髓神经元数量超过了X-gal染色的神经元数量，而与β-半乳糖苷酶阳性的红核脊髓束和蓝斑下核-脊髓神经元数量相比，HRP标记的数量较少。本研究表明，除皮质脊髓神经元外，脊髓下行传导束的起始部位可通过重组腺病毒的逆行感染有效地进行基因转移。当设计腺病毒介导的基因转移来治疗影响脊髓下行传导束的某些神经疾病时，脊髓下行传导束之间逆行感染效果的这种差异具有实际重要意义。
