Disturbance of Oligodendrocyte Function Plays a Key Role in the Pathogenesis of Schizophrenia and Major Depressive Disorder

Figure 12

Repeated exposure to WIRS (chronic stress) upregulated SGK1 and SGK1 is activated by PDK1. (a, b) In situ hybridization images of Sgk1 mRNA. Dark-field photomicrographs show the upregulation of Sgk1 mRNA expression in the fiber tracts after repeated exposure to WIRS ((a) controls; (b) stress). cc, corpus callosum; ac, anterior commissure. Scale bar = 5 mm. (c) Alternation of plasma corticosterone 24 h after repeated WIRS. The results are expressed as the mean ± SEM of three independent experiments. , -test. (d, e) The CC region images of Sgk1 mRNA in situ hybridization ((d) controls; (e) stress), respectively. Scale bar = 100 μm. (f, g) Merged images of Nissl staining and in situ hybridization images of Sgk1 mRNA. The distribution of cells expressing Sgk1 mRNA in the CC of the control (d) and repeated WIRS-exposed mice (e) in bright-filed photomicrographs. Positive grains were concentrated in the oligodendrocytes. Scale bars = 50 μm. (h, i) Western blot analysis shows SGK1 protein, its phosphorylation at positions T-256 (SGK1-256T-P) and S-422 (SGK1-422S-P), and the phosphorylation of PDK1 at position S-241 (PDK-241S-P) in the oligodendrocytes of the CC after repeated exposure to WIRS. (a)–(i) are adapted with permission from Miyata et al. [37].

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