RESUMO
The DNA papillomaviruses infect squamous epithelium and can cause persistent, benign and sometimes malignant hyperproliferative lesions. Effective antiviral drugs to treat human papillomavirus (HPV) infection are lacking and here we investigate the anti-papillomavirus activity of novel epigenetic targeting drugs, BET bromodomain inhibitors. Bromodomain and Extra-Terminal domain (BET) proteins are host proteins which regulate gene transcription, they bind acetylated lysine residues in histones and non-histone proteins via bromodomains, functioning as scaffold proteins in the formation of transcriptional complexes at gene regulatory regions. The BET protein BRD4 has been shown to be involved in the papillomavirus life cycle, as a co-factor for viral E2 and also mediating viral partitioning in some virus types. We set out to study the activity of small molecule BET bromodomain inhibitors in models of papillomavirus infection. Several BET inhibitors reduced HPV11 E1ËE4 mRNA expression in vitro and topical therapeutic administration of an exemplar compound I-BET762, abrogated CRPV cutaneous wart growth in rabbits, demonstrating translation of anti-viral effects to efficacy in vivo. Additionally I-BET762 markedly reduced viability of HPV16 infected W12â¯cells compared to non-infected C33A cells. The molecular mechanism for the cytotoxicity to W12â¯cells is unknown but may be through blocking viral-dependent cell-survival factors. We conclude that these effects, across multiple papillomavirus types and in vivo, highlight the potential to target BET bromodomains to treat HPV infection.
Assuntos
Benzodiazepinas/uso terapêutico , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Proteínas Nucleares/antagonistas & inibidores , Papillomaviridae/efeitos dos fármacos , Fatores de Transcrição/antagonistas & inibidores , Verrugas/tratamento farmacológico , Acetilação , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Epigênese Genética , Lisina , Masculino , Papillomaviridae/genética , Domínios Proteicos , Coelhos , Verrugas/virologiaRESUMO
PAD4 has been strongly implicated in the pathogenesis of autoimmune, cardiovascular and oncological diseases through clinical genetics and gene disruption in mice. New selective PAD4 inhibitors binding a calcium-deficient form of the PAD4 enzyme have validated the critical enzymatic role of human and mouse PAD4 in both histone citrullination and neutrophil extracellular trap formation for, to our knowledge, the first time. The therapeutic potential of PAD4 inhibitors can now be explored.
Assuntos
Benzimidazóis/farmacologia , Inibidores Enzimáticos/farmacologia , Hidrolases/antagonistas & inibidores , Neutrófilos/efeitos dos fármacos , Animais , Benzimidazóis/síntese química , Ligação Competitiva , Cálcio/metabolismo , Citrulina/metabolismo , Inibidores Enzimáticos/síntese química , Células HEK293 , Histonas/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Modelos Moleculares , Proteína-Arginina Desiminase do Tipo 4 , Desiminases de Arginina em Proteínas , Bibliotecas de Moléculas Pequenas , Especificidade por SubstratoRESUMO
The rapid increase in size of compound libraries, as well as new targets emerging from the Human Genome Project, require progress in ultra-high-throughput screening (uHTS) systems. In a joint effort with scientists and engineers from the biotech and the pharmaceutical industry, a modular, fully integrated system for miniaturized uHTS was developed. The goal was to achieve high data quality in small assay volumes (1-4 microL) combined with reliable and unattended operation. Two new confocal fluorescence readers have been designed. One of the instruments is a 4-channel confocal fluorescence reader, measuring with 4 objectives in parallel. The fluorescence readout is based on single-molecule detection methods, allowing high sensitivity at low tracer concentrations and delivering an information-rich output. The other instrument is a confocal fluorescence imaging reader, where the images are analyzed in terms of generic patterns and quantified in units of intensity per pixel. Both readers are spanning the application range from assays with isolated targets in homogenous solution or membrane vesicle-based assays (4-channel reader) to cell-based assays (imaging reader). Results from a comprehensive test on these assay types demonstrate the high quality and robustness of this screening system.