Figure 3

Alterations in miRNA processing in schizophrenia. (a) Simplified schematic of miRNA biogenesis showing genes involved in key enzymatic steps. (b) Primary, precursor and mature transcripts for miR-181b were analyzed by Q-PCR in the superior temporal gyrus (STG). The primary transcript was not altered in schizophrenia; however, the precursor and mature transcripts were both upregulated 1.4-fold (P=0.048) and 1.7-fold (P=0.039), respectively. The host gene of miR-26b (CDTSP1) and primary transcript were not altered. The precursor and mature miR-26b transcript were both upregulated in schizophrenia (1.5-fold (P=0.023) and 1.9-fold (P=0.001), respectively). In the dorsolateral prefrontal cortex (DLPFC), a similar trend followed. Host gene and primary transcripts were not altered in schizophrenia. For miR-181b, the precursor and mature were upregulated 1.5-fold (P=0.043) and 1.4-fold (P=0.039), respectively. For miR-26b, the precursor and mature were upregulated 1.6-fold (P=0.046) and 2.2-fold (P=0.001), respectively. (c) Expression of miRNA biogenesis genes was analyzed in the STG (n=21 matched pairs) and the DLPFC (n=15 matched pairs). DGCR8 was significantly upregulated in the STG and DLPFC, whereas Drosha and Dicer were significantly upregulated in the DLPFC only. Bars indicate mean fold change (schizophrenia to control)+s.e.m. ^*P<0.05; ^**P<0.01 unpaired Student's t-test. (d) DGCR8 expression was determined by Q-PCR in matched paired samples (SZ vs CTR). DGCR8 was upregulated in 16 out of 21 matched pairs of STG tissue and in 13 out of 15 matched pairs of DLPFC tissue.