Analysis of the structure and function of astrocytes and the microvases in preclinical models of amyotrophic lateral sclerosis

This work underscores the importance of analyzing specific disease stages and regions after in amyotrophic lateral sclerosis (ALS), paving the way for refined our understanding astrocytes functionally, important players in central nervous system. There is no treatment for ALS, so mesenchymal stromal cells (MSCs) therapy has emerged as an alternative to treat ALS, but little is known about their mechanism of action. In the in vivo experiments we analyzed astrocytes and microvases in SOD1^G93A animals after cell therapy, using human MSCs. The animals were injected with MSC or saline (vehicle) at 11 weeks of age, then at 15 and 17 weeks of age the spinal cords (SC) were prepared for immunohistochemistry or qRT-PCR. We stained the SC with GFAP and laminin to analyze the astrocytes and microvases. For qPCR, we used primers for Aquaporin 4, GFAP, C3 and S100A10. For the in vitro experiments cortical astrocytes from neonatal mice were cultivated for 7 to 10 days. After this period, conditional medium (CM) was collected and added in human brain microvascular endothelial cells HBMEC for 24hs. Astrocytes in lumbar region showed an increase of GFAP intensity in the MSC-treated animals compared to the vehicle group. We also observed an increase in the expression of Aquaporin 4, C3 and S100A10 in both regions at 15 weeks. The increase in Aquaporin 4 expression was reverted with MSCs therapy. We did not observe alterations in the percentage of area stained with laminin, but analyzing the number of vase junctions, we observed an increase between ALS mice and WT in the lumbar level at 17 weeks, not modified by the treatment. In the in vitro analysis, we observed alterations in GFAP staining, but not in GLUT1 expression. In this work, we observed significant astrogliosis and alterations in microvases in the SC of a mice model of ALS and outcomes after MSC comparing the cervical and lumbar regions. This could be influencing blood-spinal barrier permeability.