@article {49608, title = {RNA-sequencing of the brain transcriptome implicates dysregulation of neuroplasticity, circadian rhythms and GTPase binding in bipolar disorder.}, volume = {19}, year = {2014}, month = {2014 Nov}, pages = {1179-85}, abstract = {

RNA-sequencing (RNA-seq) is a powerful technique to investigate the complexity of gene expression in the human brain. We used RNA-seq to survey the brain transcriptome in high-quality postmortem dorsolateral prefrontal cortex from 11 individuals diagnosed with bipolar disorder (BD) and from 11 age- and gender-matched controls. Deep sequencing was performed, with over 350 million reads per specimen. At a false discovery rate of <5\%, we detected five differentially expressed (DE) genes and 12 DE transcripts, most of which have not been previously implicated in BD. Among these, Prominin 1/CD133 and ATP-binding cassette-sub-family G-member2 (ABCG2) have important roles in neuroplasticity. We also show for the first time differential expression of long noncoding RNAs (lncRNAs) in BD. DE transcripts include those of serine/arginine-rich splicing factor 5 (SRSF5) and regulatory factor X4 (RFX4), which along with lncRNAs have a role in mammalian circadian rhythms. The DE genes were significantly enriched for several Gene Ontology categories. Of these, genes involved with GTPase binding were also enriched for BD-associated SNPs from previous genome-wide association studies, suggesting that differential expression of these genes is not simply a consequence of BD or its treatment. Many of these findings were replicated by microarray in an independent sample of 60 cases and controls. These results highlight common pathways for inherited and non-inherited influences on disease risk that may constitute good targets for novel therapies.

}, keywords = {Adult, Aged, Bipolar Disorder, Circadian Rhythm, Female, Genome-Wide Association Study, GTP Phosphohydrolases, HUMANS, Male, Meta-Analysis as Topic, Microarray Analysis, Middle Aged, Neuronal Plasticity, Polymerase Chain Reaction, Prefrontal Cortex, Principal Component Analysis, Sequence Analysis, RNA, Transcriptome, Young Adult}, issn = {1476-5578}, doi = {10.1038/mp.2013.170}, author = {Akula, N and Barb, J and Jiang, X and Wendland, J R and Choi, K H and Sen, S K and Hou, L and Chen, D T W and Laje, G and Johnson, K and Lipska, B K and Kleinman, J E and Corrada-Bravo, H and Detera-Wadleigh, S and Munson, P J and McMahon, F J} } @article {49649, title = {Genome-wide analysis reveals novel genes essential for heme homeostasis in Caenorhabditis elegans.}, journal = {PLoS Genet}, volume = {6}, year = {2010}, month = {2010 Jul}, pages = {e1001044}, abstract = {

Heme is a cofactor in proteins that function in almost all sub-cellular compartments and in many diverse biological processes. Heme is produced by a conserved biosynthetic pathway that is highly regulated to prevent the accumulation of heme--a cytotoxic, hydrophobic tetrapyrrole. Caenorhabditis elegans and related parasitic nematodes do not synthesize heme, but instead require environmental heme to grow and develop. Heme homeostasis in these auxotrophs is, therefore, regulated in accordance with available dietary heme. We have capitalized on this auxotrophy in C. elegans to study gene expression changes associated with precisely controlled dietary heme concentrations. RNA was isolated from cultures containing 4, 20, or 500 microM heme; derived cDNA probes were hybridized to Affymetrix C. elegans expression arrays. We identified 288 heme-responsive genes (hrgs) that were differentially expressed under these conditions. Of these genes, 42\% had putative homologs in humans, while genomes of medically relevant heme auxotrophs revealed homologs for 12\% in both Trypanosoma and Leishmania and 24\% in parasitic nematodes. Depletion of each of the 288 hrgs by RNA-mediated interference (RNAi) in a transgenic heme-sensor worm strain identified six genes that regulated heme homeostasis. In addition, seven membrane-spanning transporters involved in heme uptake were identified by RNAi knockdown studies using a toxic heme analog. Comparison of genes that were positive in both of the RNAi screens resulted in the identification of three genes in common that were vital for organismal heme homeostasis in C. elegans. Collectively, our results provide a catalog of genes that are essential for metazoan heme homeostasis and demonstrate the power of C. elegans as a genetic animal model to dissect the regulatory circuits which mediate heme trafficking in both vertebrate hosts and their parasites, which depend on environmental heme for survival.

}, keywords = {Animals, Caenorhabditis elegans, Dose-Response Relationship, Drug, Gene Expression Profiling, Gene Expression Regulation, genes, Genome-Wide Association Study, Heme, Homeostasis, HUMANS, Leishmania, Nematoda, Trypanosoma}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1001044}, author = {Severance, Scott and Rajagopal, Abbhirami and Rao, Anita U and Cerqueira, Gustavo C and Mitreva, Makedonka and El-Sayed, Najib M and Krause, Michael and Hamza, Iqbal} }