RESUMO
Pluripotent stem cells (PSCs) hold great promise in cell-based therapy, but the genomic instability seen in culture hampers their full application. A greater understanding of the factors that regulate genomic stability in PSCs could help address this issue. Here we describe the identification of Filia as a specific regulator of genomic stability in mouse embryonic stem cells (ESCs). Filia expression is induced by genotoxic stress. Filia promotes centrosome integrity and regulates the DNA damage response (DDR) through multiple pathways, including DDR signaling, cell-cycle checkpoints and damage repair, ESC differentiation, and apoptosis. Filia depletion causes ESC genomic instability, induces resistance to apoptosis, and promotes malignant transformation. As part of its role in DDR, Filia interacts with PARP1 and stimulates its enzymatic activity. Filia also constitutively resides on centrosomes and translocates to DNA damage sites and mitochondria, consistent with its multifaceted roles in regulating centrosome integrity, damage repair, and apoptosis.
Assuntos
Dano ao DNA , Instabilidade Genômica , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Centrossomo/efeitos dos fármacos , Centrossomo/metabolismo , Quinase do Ponto de Checagem 2/metabolismo , Reparo do DNA/efeitos dos fármacos , Instabilidade Genômica/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/efeitos dos fármacos , Mutagênicos/toxicidade , Fosforilação/efeitos dos fármacos , Fosfosserina/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Floped (official name Ooep) is specifically and abundantly expressed in mouse oocytes and embryonic stem cells (ESCs). Depletion of Floped from oocytes leads to early embryonic arrest at the 2-cell stage. Although crucial in cleavage stage development, its roles in early embryos as well as in ESCs remain completely unknown. Here, we compared the efficiency of mouse ESC derivation from inner cell mass (ICM) with and without Floped to study its possible roles in mESCs. Derivation rates of mESC from wild-type, heterozygous, and homozygous blastocysts were 33.3%, 21.43%, and 3.85%, respectively, indicating that Floped-/- blastocysts had significantly decreased derivation rates. Respective outgrowth appearing rate five days after blastocyst attachment were 83.3%, 85.7%, and 15.4%. Morphologically, the outgrowth of ICM from Floped-/- blastocysts appeared severely death three to five days after blastocyst attachment, and the respective derived stem cells showed long-term instability with long-standing epithelial-like colonies. This result suggests a possible role of Floped in the course of ICM-ESCs transition.
