Fig. 6.

Gene and protein expression levels of MBL isoforms and complement system activation in the brain after ischemia/reperfusion in WT, MBL^−/−, MBL-A^−/−, and MBL-C^−/− mice. a Basal gene expression (fragments per kilobase million, FKPM) of Mbl1, Mbl2, and HSE-MSF (C3) in Mus musculus brain cell populations. Oligodendrocyte precursors (OPCs, expressing NG2), endothelial cells (ECs, expressing PECAM), microglia (expressing Itgam), neurons (expressing RbFox3), and astrocytes (expressing GFAP) do not express Mbl1 or Mbl2. Microglia are the only brain cell population expressing HSE-MSF (C3). Data were obtained from single-cell RNA-seq databases as described in the Materials and methods section. b Expression changes (microarray analysis) of Mbl1, Mbl2, and HSE-MSF (C3) in the brain following brain ischemia/reperfusion in WT mice. Mbl1 and Mbl2 gene expression was not induced at 3 h or 24 h after tMCAo. C3 expression was significantly upregulated at 24 h after tMCAo. The data are expressed as the log₂ fold change compared with untreated mice, with a Benjamini–Hochberg multiple comparisons test for P value adjustment, *p < 0.05 vs. untreated mice (n = 4 for each experimental group). Data were obtained from microarray databases as described in the Materials and methods section. c MBL-A and MBL-C protein presence in the brain cortices of WT, MBL-A^−/−, and MBL-C^−/− mice 48 h after tMCAo. MBL-A was present in WT and MBL-C^−/− mice to a similar extent. MBL-C was present to a higher extent in MBL-A^−/− mice than in WT mice. The data are expressed as the differences between the ipsilateral and contralateral optical densities (OD 450 nm) and are shown as bars with individual values ± SDs (n = 6); two-way ANOVA followed by Sidak’s post hoc test, **p < 0.01 and ***p < 0.001. d Representative high-magnification images of C3 immunolabeling at 48 h after tMCAo, scale bar 50 µm. e MBL^−/− and MBL-A^−/− but not MBL-C^−/− mice had less C3 deposition in the cortex than WT mice. The data are shown as bars with individual values ± SDs (n = 6–10); t test, **p < 0.01, *p < 0.05