Edalat Houri, Hajebrahimi Zahra, Pirhajati Vahid, Movahedin Mansoureh, Tavallaei Mahmoud, Soroush Mohammad-Reza, Mowla Seyed Javad
Dept. Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
Dept. of Physiology, Aerospace Research Institute, Tehran, Iran.
Iran Biomed J. 2013;17(3):140-5. doi: 10.6091/ibj.1193.2013.
Bone marrow stromal cells (BMSC) have been successfully employed for movement deficit recovery in spinal cord injury (SCI) rat models. One of the unsettled problems in cell transplantation is the relative high proportion of cell death, specifically after neural differentiation. According to our previous studies, p75 receptor, known as the death receptor, is only expressed in BMSC in a time window of 6-12 hours following neural induction. Moreover, we have recently reported a decreased level of apoptosis in p75-suppressed BMSC in vitro. Therefore, our objective in this research was to explore the functional effects of transplanting p75:siRNA expressing BMSC in SCI rats.
Laminectomy was performed at L1 vertebra level to expose spinal cord for contusion using weight-drop method. PBS-treated SCI rats (group one) were used as negative controls, in which cavitations were observed 10 weeks after SCI. pRNA-U6.1/Hygro- (group two, as a mock) and pRNA-U6.1/Hygro-p75 shRNA- (group three) transfected BMSC were labeled with a fluorescent dye, CM-DiI, and grafted into the lesion site 7 days after surgery. The Basso-Beattie-Bresnehan locomotor rating scale was performed weekly for 10 weeks.
There was a significant difference (P≤0.05) between all groups of treated rats regarding functional recovery. Specifically, the discrepancy among p75 siRNA and mock-transfected BMSC was statistically significant. P75 siRNA BMSC also revealed a higher level of in vivo survival compared to the mock BMSC.
Our data suggest that genetically modified BMSC that express p75:siRNA could be a more suitable source of cells for treatment of SCI.
骨髓基质细胞（BMSC）已成功用于脊髓损伤（SCI）大鼠模型的运动功能缺损恢复。细胞移植中尚未解决的问题之一是细胞死亡比例相对较高，特别是在神经分化后。根据我们之前的研究，p75受体，即死亡受体，仅在神经诱导后6至12小时的时间窗口内在BMSC中表达。此外，我们最近报道了体外p75抑制的BMSC中凋亡水平降低。因此，本研究的目的是探讨移植表达p75:siRNA的BMSC对SCI大鼠的功能影响。
在L1椎体水平进行椎板切除术，以暴露脊髓，采用重物坠落法造成挫伤。用PBS处理的SCI大鼠（第一组）作为阴性对照，在SCI后10周观察到空洞形成。用荧光染料CM-DiI标记pRNA-U6.1/Hygro-（第二组，作为对照）和pRNA-U6.1/Hygro-p75 shRNA-（第三组）转染的BMSC，并在手术后7天移植到损伤部位。每周进行一次Basso-Beattie-Bresnehan运动评分，持续10周。
所有治疗组大鼠在功能恢复方面存在显著差异（P≤0.05）。具体而言，p75 siRNA转染的BMSC与对照转染的BMSC之间的差异具有统计学意义。与对照BMSC相比，p75 siRNA BMSC在体内的存活率也更高。
我们的数据表明，表达p75:siRNA的基因修饰BMSC可能是治疗SCI更合适的细胞来源。
