Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA.
Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
Stem Cell Res Ther. 2023 Dec 20;14(1):378. doi: 10.1186/s13287-023-03597-w.
There are currently no effective clinical therapies to ameliorate the loss of function that occurs after spinal cord injury. Electrical stimulation of the rat spinal cord through the rat tail has previously been described by our laboratory. We propose combinatorial treatment with human induced pluripotent stem cell-derived spinal neural progenitor cells (sNPCs) along with tail nerve electrical stimulation (TANES). The purpose of this study was to examine the influence of TANES on the differentiation of sNPCs with the hypothesis that the addition of TANES would affect incorporation of sNPCs into the injured spinal cord, which is our ultimate goal.
Chronically injured athymic nude rats were allocated to one of three treatment groups: injury only, sNPC only, or sNPC + TANES. Rats were sacrificed at 16 weeks post-transplantation, and tissue was processed and analyzed utilizing standard histological and tissue clearing techniques. Functional testing was performed. All quantitative data were presented as mean ± standard error of the mean. Statistics were conducted using GraphPad Prism.
We found that sNPCs were multi-potent and retained the ability to differentiate into mainly neurons or oligodendrocytes after this transplantation paradigm. The addition of TANES resulted in more transplanted cells differentiating into oligodendrocytes compared with no TANES treatment, and more myelin was found. TANES not only promoted significantly higher numbers of sNPCs migrating away from the site of injection but also influenced long-distance axonal/dendritic projections especially in the rostral direction. Further, we observed localization of synaptophysin on SC121-positive cells, suggesting integration with host or surrounding neurons, and this finding was enhanced when TANES was applied. Also, rats that were transplanted with sNPCs in combination with TANES resulted in an increase in serotonergic fibers in the lumbar region. This suggests that TANES contributes to integration of sNPCs, as well as activity-dependent oligodendrocyte and myelin remodeling of the chronically injured spinal cord.
Together, the data suggest that the added electrical stimulation promoted cellular integration and influenced the fate of human induced pluripotent stem cell-derived sNPCs transplanted into the injured spinal cord.
目前，尚无有效的临床疗法可以改善脊髓损伤后发生的功能丧失。我们实验室之前曾描述过通过大鼠尾巴对大鼠脊髓进行电刺激。我们提出将人诱导多能干细胞衍生的脊髓神经祖细胞（sNPC）与尾巴神经电刺激（TANES）联合治疗。本研究的目的是研究 TANES 对 sNPC 分化的影响，假设 TANES 的加入会影响 sNPC 整合到受损的脊髓中，这是我们的最终目标。
慢性损伤的无胸腺裸鼠被分配到以下三个治疗组之一：仅损伤、仅 sNPC 或 sNPC+TANES。移植后 16 周处死大鼠，使用标准组织学和组织透明化技术处理和分析组织。进行功能测试。所有定量数据均以平均值±平均值标准误差表示。使用 GraphPad Prism 进行统计分析。
我们发现 sNPC 具有多能性，并且在这种移植范例后仍保留分化为主要神经元或少突胶质细胞的能力。与无 TANES 处理相比，TANES 的加入导致更多移植细胞分化为少突胶质细胞，并且发现更多的髓鞘。TANES 不仅促进了显著更多的 sNPC 从注射部位迁移，而且还影响了长距离轴突/树突投射，特别是在头侧方向。此外，我们观察到 SC121 阳性细胞上突触小体蛋白的定位，表明与宿主或周围神经元的整合，并且当施加 TANES 时，这种发现得到了增强。此外，与 TANES 联合移植 sNPC 的大鼠在腰部区域增加了 5-羟色胺能纤维。这表明 TANES 有助于 sNPC 的整合，以及慢性损伤脊髓中活动依赖性少突胶质细胞和髓鞘重塑。
总之，数据表明，外加的电刺激促进了细胞的整合，并影响了移植到受损脊髓中的人诱导多能干细胞衍生的 sNPC 的命运。
