RESUMEN
The pluripotent state of embryonic stem cells (ESCs) is regulated by a sophisticated network of transcription factors. High expression of KLF17 has recently been identified as a hallmark of naive state of human ESCs (hESCs). However, the functional role of KLF17 in naive state is not clear. Here, by employing various gain and loss-of-function approaches, we demonstrate that KLF17 is essential for the maintenance of naive state and promotes the primed to naive state transition in hESCs. Mechanistically, we identify MAPK3 and ZIC2 as two direct targets repressed by KLF17. Overexpression of MAPK3 or ZIC2 partially blocks KLF17 from promoting the naive pluripotency. Furthermore, we find that human and mouse homologs of KLF17 retain conserved functions in promoting naive pluripotency of both species. Finally, we show that Klf17 may be essential for early embryo development in mouse. These findings demonstrate the important and conserved function of KLF17 in promoting naive pluripotency and reveal two essential transcriptional targets of KLF17 that underlie its function.
Asunto(s)
Células Madre Embrionarias Humanas , Animales , Diferenciación Celular/genética , Células Madre Embrionarias/metabolismo , Células Madre Embrionarias Humanas/metabolismo , Humanos , Ratones , Proteína Quinasa 3 Activada por Mitógenos , Proteínas Nucleares/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Long noncoding RNAs (lncRNAs) have emerged as important components of gene regulatory network in embryonic stem cells (ESCs). However, the function and molecular mechanism of lncRNAs are still largely unknown. Here we identifies Trincr1 (TRIM71 interacting long noncoding RNA 1) lncRNA that regulates the FGF/ERK signaling and self-renewal of ESCs. Trincr1 is exported by THOC complex to cytoplasm where it binds and represses TRIM71, leading to the downregulation of SHCBP1 protein. Knocking out Trincr1 leads to the upregulation of phosphorylated ERK and ERK pathway target genes and the decrease of ESC self-renewal, while knocking down Trim71 completely rescues the defects of Trincr1 knockout. Furthermore, ectopic expression of Trincr1 represses FGF/ERK signaling and the self-renewal of neural progenitor cells (NPCs). Together, this study highlights lncRNA as an important player in cell signaling network to coordinate cell fate specification.
Asunto(s)
Factores de Crecimiento de Fibroblastos/genética , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/genética , Células Madre Embrionarias de Ratones/metabolismo , ARN Largo no Codificante/genética , Factores de Transcripción/genética , Animales , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Embrión de Mamíferos , Factores de Crecimiento de Fibroblastos/metabolismo , Regulación del Desarrollo de la Expresión Génica , Redes Reguladoras de Genes , Sistema de Señalización de MAP Quinasas , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Células Madre Embrionarias de Ratones/citología , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Fosforilación , Unión Proteica , ARN Largo no Codificante/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas Adaptadoras de la Señalización Shc/genética , Proteínas Adaptadoras de la Señalización Shc/metabolismo , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/metabolismoRESUMEN
Post-transcriptional and translational regulations play essential roles during cellular reprogramming and in the maintenance and differentiation of pluripotent stem cells (PSCs). MicroRNAs (miRNAs) control cell cycle, glycolysis, chromatin state, survival and pluripotency of ESCs. Likewise, many miRNAs assist or act as a barrier for the generation of induced pluripotent stem cells (iPSCs). Recent studies also reveal exciting new directions on miRNA functions in regulating the switch between naive and primed pluripotent states as well as the establishment of totipotent-like state. Furthermore, the biogenesis and function of pluripotency related miRNAs are regulated by various RNA binding proteins (RBPs) at different levels. Revealing the interplay between RBPs and miRNAs will advance our understanding of molecular mechanisms controlling pluripotency and provide better means to manipulate PSCs for clinical applications. In this review, we summarize recent findings on the function of miRNAs in ESCs and during reprogramming. In addition, we also discuss new directions on miRNA functions in regulating the switch between different pluripotent states and RBP-mediated regulation of miRNA biogenesis and function in pluripotency control.
Asunto(s)
Reprogramación Celular/genética , MicroARNs/genética , Células Madre Pluripotentes , Proteínas de Unión al ARN/genética , Animales , Diferenciación Celular/genética , Regulación del Desarrollo de la Expresión Génica , HumanosRESUMEN
Attenuated Listeria monocytogenes (L. monocytogenes, LM) induces specific CD8+ and CD4+ T cell responses, and has been identified as a promising cancer vaccine vector. Cervical cancer is the third most common cancer in women worldwide, with human papillomavirus (HPV), particularly type 16, being the main etiological factor. The therapeutic HPV vaccines are urgently needed. The E7 protein of HPV is necessary for maintaining malignancy in tumor cells. Here, a genetically modified attenuated LM expressing HPV16 E7 protein was constructed. Intraperitoneal vaccination of LM4Δhly::E7 significantly reduced tumor size and even resulted in complete regression of established tumors in a murine model of cervical cancer. We provided evidence that recombinant LM strains could enter the tumor tissue and induce non-specific tumor cell death, probably via activation of reactive oxygen species and increased intracellular Ca2+ levels. LM4Δhly::E7 effectively triggered a strong antigen-specific cellular immunity in tumor-bearing mice, and elicited significant infiltration of T cells in the intratumoral milieu. In summary, these data showed LM4Δhly::E7 to be effective in a cervical cancer model and LM4Δhly::E7 induced an antitumor effect by antigen-specific cellular immune responses and direct killing of tumor cells, indicating a potential application against cervical cancer.
Asunto(s)
Vacunas contra el Cáncer/administración & dosificación , Vectores Genéticos/genética , Papillomavirus Humano 16/inmunología , Listeria monocytogenes/genética , Proteínas E7 de Papillomavirus/inmunología , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/inmunología , Neoplasias del Cuello Uterino/prevención & control , Vacunas Atenuadas/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Vacunas contra el Cáncer/genética , Vacunas contra el Cáncer/inmunología , Línea Celular Tumoral , Femenino , Vectores Genéticos/inmunología , Papillomavirus Humano 16/genética , Humanos , Listeria monocytogenes/inmunología , Ratones , Ratones Endogámicos C57BL , Proteínas E7 de Papillomavirus/administración & dosificación , Proteínas E7 de Papillomavirus/genética , Infecciones por Papillomavirus/inmunología , Infecciones por Papillomavirus/virología , Vacunas contra Papillomavirus/administración & dosificación , Vacunas contra Papillomavirus/genética , Neoplasias del Cuello Uterino/inmunología , Neoplasias del Cuello Uterino/virología , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/genéticaRESUMEN
The molecular mechanism controlling the dismantling of naive pluripotency is poorly understood. Here we show that microRNAs (miRNAs) have important roles during naive to primed pluripotency transition. Dgcr8(-/-) embryonic stem cells (ESCs) failed to completely silence the naive pluripotency program, as well as to establish the primed pluripotency program during differentiation. miRNA profiling revealed that expression levels of a large number of miRNAs changed dynamically and rapidly during naive to primed pluripotency transition. Furthermore, a miRNA screen identified numerous miRNAs promoting naive to primed pluripotency transition. Unexpectedly, multiple miRNAs from miR-290 and miR-302 clusters, previously shown as pluripotency-promoting miRNAs, demonstrated the strongest effects in silencing naive pluripotency. Knockout of both miR-290 and miR-302 clusters but not either alone blocked the silencing of naive pluripotency program. Mechanistically, the miR-290/302 family of miRNAs may facilitate the exit of naive pluripotency in part by promoting the activity of MEK pathway and through directly repressing Akt1. Our study reveals miRNAs as an important class of regulators potentiating ESCs to transition from naive to primed pluripotency, and uncovers context-dependent functions of the miR-290/302 family of miRNAs at different developmental stages.