Expression of BACE1, BACE1-AS and miR-485-5p in different brain regions. (a) Expression of miR-485-5p, BACE1 and BACE1-AS were measured in a commercially available panel of human tissues (n = 1), including brain, liver, heart, skeletal (Sk) muscle, spleen, kidney, testis and lung, by RT-PCR. Whole brain RNA shows a much higher abundance of miR-485-5p (y-axis is log2% of brain). BACE1 mRNA was ubiquitously expressed, with the highest expression in brain. BACE1-AS transcript was expressed in all tissues, but relatively higher in brain, heart, skeletal muscle and testis. (b) Expression of miR-485-5p, BACE1 and BACE1-AS transcripts were measured in several mouse brain region as well as mouse liver (n = 3). miR-485-5p is readily present in various brain regions, but it is not evenly distributed in all regions tested. BACE1 and BACE1-AS transcripts are also highly expressed in all brain regions that are affected by Alzheimer's disease pathologies. (c) Expression of miR-485-5p, BACE1 and BACE1-AS transcripts were measured in four human brain regions. RNA originated from cerebellum (18 subjects), entorhinal cortex (8 subjects), hippocampus (12 subjects) and superior frontal gyrus (18 subjects). miR-485-5p was two- to four-fold higher in entorhinal cortex, hippocampus and superior frontal gyrus compared to cerebellum. BACE1-AS transcript was expressed two- to three-fold lower in entorhinal cortex, hippocampus and superior frontal gyrus compared to cerebellum. BACE1 mRNA is almost equally distributed in all four regions. (d) The small RNA fraction from two individuals for each of eight tissues (with the exception of the kidney, which had only one sample) was used for high-throughput short read sequencing. After alignment of reads to the human genome, the reads corresponding to miR-485-5p were identified and normalized to the total number of reads. There was significantly higher abundance of miR-485-5p in the orbital gyrus of the brain compared to skeletal muscle, pancreas, lung, heart, liver, spleen and kidney.
Faghihi et al. Genome Biology 2010 11:R56 doi:10.1186/gb-2010-11-5-r56