Figure 6

C1q expression is an early response in Nestin-Pex5 ^−/− brain. (A) C1q expression levels were quantified by qRT-PCR. Up regulation of mRNA levels was already significant in the corpus callosum of the three-week-old Nestin-Pex5 ^−/−, although this was much more pronounced at six weeks. Expression levels were normalized to β-actin expression. Values are given as means ± SEM of four independent samples. ** P < 0.01, *** P < 0.001 (Student’s t-test). (B-E) C1q was also investigated by immunohistochemistry. At six weeks, C1q immunoreactivity was observed in the corpus callosum (D) and brain stem (C), but not in the cerebellum (E). Double labeling of C1q (green) and microglia (F4/80, red) or oligodendrocytes (CC-1, red), respectively, was performed to determine the cellular localization of the complement protein. C1q was not present in microglia (B and D), but in a subset of oligodendrocytes (C). Scale bars: B and E: 50 μm; C and D: 20 μm. SEM, standard error of the mean.