Figure 3.

Impact of the PDYN p.R138S Mutation on Expression of the Opioid Genes and PDYN Levels in Human Brain

(A) Levels of opioid mRNA in the nucleus accumbens (NAc), prefrontal cortex (PFC), and cerebellum (Cb) were quantified by TaqMan low-density arrays in postmortem samples from three control subjects. PDYN expression was substantially lower in Cb compared to NAc and PFC, the two brain areas with high and moderate gene expression. In the Cb, PENK showed high expression levels compared to the PFC but lower expression levels compared to the NAc. Both OPRK1 and OPRM1 are expressed in Cb, NAc, and PFC at similar levels, whereas OPRD1 expression was not detectable in the Cb. Data bars represent the means ± SEM.

(B) Comparison of mRNA levels in the Cb between three control and SCA23 cerebella. The data is shown as the ratio of levels in SCA23 to those in controls. Mean levels in controls were set to 1, as indicated by the dashed line. PENK, OPRK1, and OPRM1 expression was 2- and 3.5-fold increased, whereas PDYN expression was slightly decreased in the SCA23 Cb compared to controls.

(C) Analysis of PDYN in the human NAc, PFC, and Cb by immunoblot analysis. Tissue samples were pooled from three control subjects and purified on SEP-PAC reverse-phase columns prior to SDS-PAGE. PDYN levels in cerebellum are intermediate between those in NAc and PFC.

(D) No differences were evident between PDYN levels in control (C1-3) and SCA23 cerebella.