RESUMO
Nutritional intake impacts the human epigenome by directing epigenetic pathways in normal cell development via as yet unknown molecular mechanisms. Consequently, imbalance in the nutritional intake is able to dysregulate the epigenetic profile and drive cells towards malignant transformation. Here we present a novel epigenetic effect of the essential nutrient, NAD. We demonstrate that impairment of DNMT1 enzymatic activity by NAD-promoted ADP-ribosylation leads to demethylation and transcriptional activation of the CEBPA gene, suggesting the existence of an unknown NAD-controlled region within the locus. In addition to the molecular events, NAD- treated cells exhibit significant morphological and phenotypical changes that correspond to myeloid differentiation. Collectively, these results delineate a novel role for NAD in cell differentiation, and indicate novel nutri-epigenetic strategies to regulate and control gene expression in human cells.
Assuntos
Diferenciação Celular , Metilação de DNA/genética , NAD/farmacologia , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Desmetilação do DNA/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Células Mieloides/citologia , Células Mieloides/efeitos dos fármacos , Neoplasias/genética , Neoplasias/patologia , Fosforilação Oxidativa/efeitos dos fármacos , Poli Adenosina Difosfato Ribose/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcrição Gênica/efeitos dos fármacosRESUMO
ADP-ribosylation, is a reversible post-translational modification implicated in major biological functions. Poly ADP-ribose polymerases (PARP) are specialized enzymes that catalyze the addition of ADP ribose units from "nicotinamide adenine dinucleotide-donor molecules" to their target substrates. This reaction known as PARylation modulates essential cellular processes including DNA damage response, chromatin remodeling, DNA methylation and gene expression. Herein, we discuss emerging roles of PARP1 in chromatin remodeling and epigenetic regulation, focusing on its therapeutic implications for cancer treatment and beyond.
