Zheng Meige, Duan Junxiu, He Zhendan, Wang Zhiwei, Mu Shuhua, Zeng Zhiwen, Qu Junle, Zhang Jian, Wang Dong
Department of Orthopedic and Microsurgery, The First Affiliated Hospital of Sun Yat-Sen University, No. 58 Zhongshan Road 2, Guangzhou, China; Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, China.
School of Medicine, Shenzhen University, Shenzhen, China.
Cytotherapy. 2016 Oct;18(10):1256-69. doi: 10.1016/j.jcyt.2016.06.015. Epub 2016 Aug 3.
Bone marrow stromal cells (BMSCs) can differentiate into Schwann-like cells in vivo and effectively promote nerve regeneration and functional recovery as the seed cells for peripheral nerve repair. However, the survival rate and neural differentiation rate of the transplanted BMSCs are very low, which would limit their efficacy.
In this work, rat BMSCs were infected by recombinant lentiviruses to construct tropomyosin receptor kinase A (TrkA)-overexpressing BMSCs and TrkA-shRNA-expressing BMSCs, which were then used in transplantation for rat sciatic nerve defects.
We showed that lentivirus-mediated overexpression of TrkA in BMSCs can promote cell survival and protect against serum-starve-induced apoptosis in vitro. At 8 weeks after transplantation, the Schwann-like differentiated ratio of the existing implanted cells had reached 74.8 ± 1.6% in TrkA-overexpressing BMSCs-laden nerve grafts, while 40.7 ± 2.3% and 42.3 ± 1.5% in vector and control BMSCs-laden nerve grafts, but only 8.2 ± 1.8% in TrkA-shRNA-expressing BMSCs-laden nerve grafts. The cell apoptosis ratio of the existing implanted cells in TrkA-overexpressing BMSCs-laden nerve grafts was 16.5 ± 1.2%, while 33.9 ± 1.9% and 42.6 ± 2.9% in vector and control BMSCs-laden nerve grafts, but 87.2 ± 2.5% in TrkA-shRNA-expressing BMSCs-laden nerve grafts.
These results demonstrate that TrkA overexpression can improve the survival and Schwann-like cell differentiation of BMSCs and prevent cell death in nerve grafts, which may have potential implication in advancing cell transplantation for peripheral nerve repair.
骨髓基质细胞（BMSCs）在体内可分化为类施万细胞，并作为周围神经修复的种子细胞有效促进神经再生和功能恢复。然而，移植的BMSCs存活率和神经分化率很低，这将限制其疗效。
在本研究中，用重组慢病毒感染大鼠BMSCs，构建过表达原肌球蛋白受体激酶A（TrkA）的BMSCs和表达TrkA-shRNA的BMSCs，然后将其用于大鼠坐骨神经缺损的移植。
我们发现慢病毒介导的BMSCs中TrkA过表达可促进细胞存活并在体外保护细胞免受血清饥饿诱导的凋亡。移植后8周，在负载过表达TrkA的BMSCs的神经移植物中，现存植入细胞的类施万细胞分化率达到74.8±1.6%，而在负载载体和对照BMSCs的神经移植物中分别为40.7±2.3%和42.3±1.5%，但在负载表达TrkA-shRNA的BMSCs的神经移植物中仅为8.2±1.8%。在负载过表达TrkA的BMSCs的神经移植物中，现存植入细胞的凋亡率为16.5±1.2%，而在负载载体和对照BMSCs的神经移植物中分别为33.9±1.9%和42.6±2.9%，但在负载表达TrkA-shRNA的BMSCs的神经移植物中为87.2±2.5%。
这些结果表明，TrkA过表达可提高BMSCs的存活率和类施万细胞分化率，并防止神经移植物中的细胞死亡，这可能对推进周围神经修复的细胞移植具有潜在意义。
