RESUMO
Lithium inhibits inositol monophosphatase at therapeutically effective concentrations, and it has been hypothesized that depletion of brain inositol levels is an important chemical alteration for lithium's therapeutic efficacy in bipolar disorder. We have employed adult rat cortical slices as a model to investigate the gene regulatory consequences of inositol depletion effected by lithium using cytidine diphosphoryl-diacylglycerol as a functionally relevant biochemical marker to define treatment conditions. Genes coding for the neuropeptide hormone pituitary adenylate cyclase activating polypeptide (PACAP) and the enzyme that processes PACAP's precursor to the mature form, peptidylglycine alpha-amidating monooxygenase, were upregulated by inositol depletion. Previous work has shown that PACAP can increase tyrosine hydroxylase (TH) activity and dopamine release, and we found that the gene for GTP cyclohydrolase, which effectively regulates TH through synthesis of tetrahydrobiopterin, was also upregulated by inositol depletion. We propose that modulation of brain PACAP signaling might represent a new opportunity in the treatment of bipolar disorder.
Assuntos
Antimaníacos/farmacologia , Biopterinas/análogos & derivados , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Inositol/metabolismo , Cloreto de Lítio/farmacologia , Animais , Biomarcadores/metabolismo , Biopterinas/metabolismo , Transtorno Bipolar/metabolismo , Córtex Cerebral/fisiopatologia , Diglicerídeos de Citidina Difosfato/metabolismo , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , GTP Cicloidrolase/genética , GTP Cicloidrolase/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/fisiologia , Masculino , Oxigenases de Função Mista/metabolismo , Complexos Multienzimáticos/metabolismo , Fatores de Crescimento Neural/biossíntese , Neuropeptídeos/biossíntese , Neurotransmissores/biossíntese , Análise de Sequência com Séries de Oligonucleotídeos , Técnicas de Cultura de Órgãos , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Ratos , Ratos Sprague-Dawley , Tirosina 3-Mono-Oxigenase/biossíntese , Regulação para Cima/genéticaRESUMO
Microarrays offer a high-resolution means for monitoring pre-mRNA splicing on a genomic scale. We have developed a novel, unbiased amplification protocol that permits labeling of entire transcripts. Also, hybridization conditions, probe characteristics, and analysis algorithms were optimized for detection of exons, exon-intron edges, and exon junctions. These optimized protocols can be used to detect small variations and isoform mixtures, map the tissue specificity of known human alternative isoforms, and provide a robust, scalable platform for high-throughput discovery of alternative splicing.
