Ballout Nissrine, Rochelle Tristan, Brot Sebastien, Bonnet Marie-Laure, Francheteau Maureen, Prestoz Laetitia, Zibara Kazem, Gaillard Afsaneh
Laboratoire de Neurosciences Expérimentales et Cliniques, Université de Poitiers, INSERM U1084, Poitiers, France.
Laboratory of Stem Cells, PRASE, DSST, Department of Biology, Faculty of Sciences-I, Lebanese University, Beirut, Lebanon.
Front Mol Neurosci. 2019 Jun 25;12:160. doi: 10.3389/fnmol.2019.00160. eCollection 2019.
We previously reported that embryonic motor cortical neurons transplanted 1-week after lesion in the adult mouse motor cortex significantly enhances graft vascularization, survival, and proliferation of grafted cells, the density of projections developed by grafted neurons and improves functional repair and recovery. The purpose of the present study is to understand the extent to which post-traumatic inflammation following cortical lesion could influence the survival of grafted neurons and the development of their projections to target brain regions and conversely how transplanted cells can modulate host inflammation. For this, embryonic motor cortical tissue was grafted either immediately or with a 1-week delay into the lesioned motor cortex of adult mice. Immunohistochemistry (IHC) analysis was performed to determine the density and cell morphology of resident and peripheral infiltrating immune cells. Then, hybridization (ISH) was performed to analyze the distribution and temporal mRNA expression pattern of pro-inflammatory or anti-inflammatory cytokines following cortical lesion. In parallel, we analyzed the protein expression of both M1- and M2-associated markers to study the M1/M2 balance switch. We have shown that 1-week after the lesion, the number of astrocytes, microglia, oligodendrocytes, and CD45+ cells were significantly increased along with characteristics of M2 microglia phenotype. Interestingly, the majority of microglia co-expressed transforming growth factor-β1 (TGF-β1), an anti-inflammatory cytokine, supporting the hypothesis that microglial activation is also neuroprotective. Our results suggest that the modulation of post-traumatic inflammation 1-week after cortical lesion might be implicated in the improvement of graft vascularization, survival, and density of projections developed by grafted neurons.
我们之前报道过，在成年小鼠运动皮层损伤1周后移植胚胎运动皮层神经元，可显著增强移植物的血管化、移植细胞的存活和增殖、移植神经元形成的投射密度，并改善功能修复和恢复。本研究的目的是了解皮层损伤后的创伤后炎症在多大程度上会影响移植神经元的存活及其向目标脑区投射的发育，反之，移植细胞如何调节宿主炎症。为此，将胚胎运动皮层组织立即或延迟1周移植到成年小鼠损伤的运动皮层中。进行免疫组织化学（IHC）分析以确定驻留和外周浸润免疫细胞的密度和细胞形态。然后，进行原位杂交（ISH）以分析皮层损伤后促炎或抗炎细胞因子的分布和时间mRNA表达模式。同时，我们分析了M1和M2相关标志物的蛋白表达，以研究M1/M2平衡转换。我们已经表明，损伤1周后，星形胶质细胞、小胶质细胞、少突胶质细胞和CD45+细胞的数量显著增加，同时伴有M2小胶质细胞表型特征。有趣的是，大多数小胶质细胞共表达抗炎细胞因子转化生长因子-β1（TGF-β1），支持小胶质细胞激活也具有神经保护作用这一假说。我们的结果表明，皮层损伤1周后创伤后炎症的调节可能与移植神经元的移植物血管化、存活和投射密度的改善有关。
