Fig. 7

Cr2 is expressed by astrocytes in vitro, and levels of soluble CR2 are increased in cerebrospinal fluid of rats following ventral root avulsion. The expression pattern of Cr2 was similar to that of Gfap suggesting astrocytes as a likely source. To confirm that astrocytes and not microglia were the main source of Cr2 expression, cultures of both glia types were generated from adult PVG rats and stimulated with TNF-α. Cr2 expression was not detectable in microglia, whereas Cr2 was expressed by astrocytes although TNF-α stimulation did not lead to a significant increase in levels (a). CD11b expression was 100- to 1000-fold higher in microglia as compared to astrocytes and increased following TNF-α stimulation (b). CSF was collected from PVG rats subjected to VRA. Levels of soluble CR2, sCR2, were increased in injured compared to healthy rats, as measured with Elisa (c). *p < 0.05, **p < 0.01, and ***p < 0.001, the in vitro experiments were repeated three times with equal results. The results are represented as mean ± SEM