Resumo

Mesenchymal stem cells from human adipose tissue promotes regeneration after spinal cord injury Spinal cord injury causes profound changes in the nervous microenvironment that culminate in axonal degeneration and demyelization. In the acute phase, bleeding causes local hypoxia, which, combined with the production of inhibitory molecules and inflammatory mediators, lead to the destruction of neuronal tissue. Mesenchymal stem cells from adipose tissue (AT-MSC) have been shown to differentiate into different cell types and to participate in the angiogenic process. Here we investigate the effect of human AT-MSC in SCI. Acute local injection of hAT-MSC was performed after thoracic compression or complete transection (105 cells diluted in 10 ul of DMEM). In both models there was a significant improvement in locomotor function. In complete transaction, the BBB score 8 weeks after lesion was 100% higher in the experimental group treated than in the DMEM control. One week after injection, hAT-MSC could be visualized at the innermost pia mater layer and along the midline of the spinal cord. They were also able to migrate to the epicenter of the lesion. Morphological analyses of the experimental animals showed that treatment reduced the area of the cystic cavity and increased the number of cell bodies and fibers labeled with the neuronal regeneration marker GAP-43. It was also verified that hAT-MSC participated actively in the angiogenic process and increased the amount of small blood vessels along the central canal, as well as in white and gray matters. Neovascularization of the spinal parenchyma could explain the beneficial effects of hAT-MSC, since it would increase the oxygen supply to the cells, thus preventing the progression of ischemic necrosis. Finally, we observed no sign of rejection of grafted human cells, which confirms the immunomodulatory character previously proposed for MSCs