Figure 2

Classical MHC I and Iba-1 double-staining in C57BL6/J and iNOS^-/- mice, one and two weeks after axotomy. Observe the significantly stronger upregulation of MHC I (ER-Hr52) labeling in C57BL6/J (WT) mice one week after lesion (B), which is co-localized with microglial Iba-1 positive cells (C). The lesioned side (F) of the spinal cord of iNOS^-/- mice shows almost no labeling, (A and E) Iba-1 labeling on the lesioned side of C57BL6/J and iNOS^-/- mice, respectively. Two weeks after lesioning, ER-HR52 immunolabeling is even stronger than in the acute phase (D). (H) No MHC I labeling was seen in the ventral horn of iNOS^-/- mice, two weeks after sciatic transection. (I). Western blotting analysis of MHC I expression in spinal cord ventral horn ipsi- and contralateral to axotomy. Note the upregulation of MHC I in wild type mice after lesion, which is not observed in iNOS^-/- animals. β-Actin was used as sample loading control. IL = ipsilateral; CL = contralateral. * = p < 0.05; ** = p < 0.01 (Mann-Whitney U test). (J) Graph representing quantification of the integrated density of pixels for MHC I immunolabeling in the neuropil adjacent to large motoneurons, one (1 w) and two (2 w) weeks after axotomy. * = p < 0.05, Student t test. Scale bar = 50 μm.