RESUMO
Almost all protein-coding genes are spliced and their majority is alternatively spliced. Alternative splicing is a key element in eukaryotic gene expression that increases the coding capacity of the human genome and an increasing number of examples illustrates that the selection of wrong splice sites causes human disease. A fine-tuned balance of factors regulates splice site selection. Here, we discuss well-studied examples that show how a disturbance of this balance can cause human disease. The rapidly emerging knowledge of splicing regulation now allows the development of treatment options.
Assuntos
Processamento Alternativo , Doença/genética , Animais , Sequência de Bases , Disautonomia Familiar/genética , Éxons , Feminino , Hiperlipoproteinemia Tipo II/genética , Masculino , Modelos Genéticos , Dados de Sequência Molecular , Atrofia Muscular Espinal/genética , Neoplasias/genética , Conformação de Ácido Nucleico , Progéria/genética , Precursores de RNA/química , Precursores de RNA/genética , Precursores de RNA/metabolismo , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Transdução de Sinais , Spliceossomos/metabolismo , Tauopatias/genéticaRESUMO
The development of multidrug-resistant viruses compromises antiretroviral therapy efficacy and limits therapeutic options. Therefore, it is an ongoing task to identify new targets for antiretroviral therapy and to develop new drugs. Here, we show that an indole derivative (IDC16) that interferes with exonic splicing enhancer activity of the SR protein splicing factor SF2/ASF suppresses the production of key viral proteins, thereby compromising subsequent synthesis of full-length HIV-1 pre-mRNA and assembly of infectious particles. IDC16 inhibits replication of macrophage- and T cell-tropic laboratory strains, clinical isolates, and strains with high-level resistance to inhibitors of viral protease and reverse transcriptase. Importantly, drug treatment of primary blood cells did not alter splicing profiles of endogenous genes involved in cell cycle transition and apoptosis. Thus, human splicing factors represent novel and promising drug targets for the development of antiretroviral therapies, particularly for the inhibition of multidrug-resistant viruses.
Assuntos
Antirretrovirais/farmacologia , Farmacorresistência Viral/genética , HIV/efeitos dos fármacos , Indóis/farmacologia , Isoquinolinas/farmacologia , Precursores de RNA/efeitos dos fármacos , Splicing de RNA/efeitos dos fármacos , Carbazóis/farmacologia , Avaliação Pré-Clínica de Medicamentos , Ensaio de Imunoadsorção Enzimática , HIV/genética , Humanos , Leucócitos Mononucleares/virologia , Macrófagos/virologia , RNA Viral/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Replicação Viral/efeitos dos fármacosRESUMO
Cognitive dysfunction is increasingly recognized as a symptom in mental conditions including schizophrenia, major depressive disorder (MDD), and bipolar disorder (BPD). Despite the many available cognitive assessment instruments, consensus is lacking on their appropriate use in clinical trials. We conducted a systematic literature review in Embase, PubMed/Medline and PsychINFO to identify appropriate cognitive function instruments for use in clinical trials of schizophrenia, MDD, and BPD. Instruments were identified from the articles. Instruments and articles were excluded if they did not address schizophrenia, MDD, or BPD. Instrument appropriateness was further assessed by the criteria of the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative: test-retest reliability, utility, relationship to functional status, potential changeability to pharmacological agents, and tolerability and practicality for clinical trials. The database search yielded 173 articles describing 150 instruments used to assess cognitive function. Seventeen additional instruments were identified through Google and clinicaltrials.gov. Among all these, only 30 (18%) were deemed appropriate for use in the diseases of interest. Of these, 27 were studied in schizophrenia, one in MDD and two in BPD. These findings suggest the need for careful selection of appropriate cognitive assessment instruments, as not all may be valid in these disorders.
Assuntos
Transtorno Bipolar/psicologia , Ensaios Clínicos como Assunto/métodos , Transtornos Cognitivos/diagnóstico , Cognição/fisiologia , Transtorno Depressivo Maior/psicologia , Psicologia do Esquizofrênico , Transtorno Bipolar/complicações , Transtorno Bipolar/diagnóstico , Transtornos Cognitivos/complicações , Bases de Dados Bibliográficas , Transtorno Depressivo Maior/complicações , Transtorno Depressivo Maior/diagnóstico , Humanos , Reprodutibilidade dos Testes , Esquizofrenia/complicações , Esquizofrenia/diagnósticoRESUMO
The retroviral life cycle requires that significant amounts of RNA remain unspliced and perform several functions in the cytoplasm. Thus, the full-length RNA serves both the viral genetic material that will be encapsulated in viral particles and the mRNA encoding structural and enzymatic proteins required for viral replication. Simple retroviruses produce one single-spliced env RNA from the full-length precursor RNA, whereas complex retroviruses, such as HIV, are characterized by the production of multiple-spliced RNA species. In this review we will summarize the current acknowledge about the HIV-1 alternative splicing mechanism and will describe how this malleable process can help further understanding of infection, spread and dissemination through splicing regulation. Such studies coupled with the testing of splicing inhibitors should help the development of new therapeutic antiviral agents.
Assuntos
Processamento Alternativo , Antirretrovirais/farmacologia , Infecções por HIV/tratamento farmacológico , HIV-1/fisiologia , Replicação Viral/efeitos dos fármacos , Processamento Alternativo/efeitos dos fármacos , Sequência de Bases , Infecções por HIV/fisiopatologia , HIV-1/genética , Humanos , Dados de Sequência MolecularRESUMO
Pre-mRNA splicing is an essential step of the expression of most metazoan protein-coding genes, which is often regulated in a cell type-specific or developmental manner. We have demonstrated previously that human DNA topoisomerase I, an extensively studied target for anticancer drugs, also has an intrinsic protein kinase activity that specifically phosphorylates proteins involved in splice site selection. Therefore, DNA topoisomerase I was recently shown to play a critical role in alternative splicing. Here, we have exploited these novel properties of DNA topoisomerase I to develop entirely novel diospyrin derivatives targeting its protein kinase activity and thereby modulating pre-mRNA splicing. Although some derivatives indeed inhibit kinase activity of topoisomerase I, they did not block reactions of topoisomerase I on DNA. However, these drugs interfere with camptothecin-dependent topoisomerase I-mediated DNA cleavage, implying that diospyrin derivatives mediate a conformational change of topoisomerase I. It is note-worthy that in vitro splicing reactions revealed that diospyrin derivatives alter various steps of splicing. Some diospyrin derivatives inhibit either the first or the second catalytic step of splicing but not spliceosome assembly, whereas diospyrin itself prevents the formation of full spliceosome. Our data revealed for the first time that diospyrin derivatives are able to stall the dynamic assembly of the spliceosome and open the exciting possibility of using these derivatives to correct aberrant splicing in human genetic diseases.
Assuntos
Inibidores Enzimáticos/farmacologia , Naftoquinonas/farmacologia , Spliceossomos/efeitos dos fármacos , Inibidores da Topoisomerase I , DNA/metabolismo , Fosforilação , Splicing de RNA/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
The prevalence of alternative splicing as a target for alterations leading to human genetic disorders makes it highly relevant for therapy. Here we have used in vitro splicing reactions with different splicing reporter constructs to screen 4,000 chemical compounds for their ability to selectively inhibit spliceosome assembly and splicing. We discovered indole derivatives as potent inhibitors of the splicing reaction. Importantly, compounds of this family specifically inhibit exonic splicing enhancer (ESE)-dependent splicing, because they interact directly and selectively with members of the serine-arginine-rich protein family. Treatment of cells expressing reporter constructs with ESE sequences demonstrated that selected indole derivatives mediate inhibition of ESE usage in vivo and prevent early splicing events required for HIV replication. This discovery opens the exciting possibility of a causal pharmacological treatment of aberrant splicing in human genetic disorders and development of new antiviral therapeutic approaches.