Stability of Imprinting and Differentiation Capacity in Naïve Human Cells Induced by Chemical Inhibition of CDK8 and CDK19

Pluripotent stem cells can be stabilized in vitro at different developmental states by the use of specific chemicals and soluble factors. The naïve and primed states are the best characterized pluripotency states. Naïve pluripotent stem cells (PSCs) correspond to the early pre-implantation blastocyst and, in mice, constitute the optimal starting state for subsequent developmental applications. However, the stabilization of human naïve PSCs remains challenging because, after short-term culture, most current methods result in karyotypic abnormalities, aberrant DNA methylation patterns, loss of imprinting and severely compromised developmental potency. We have recently developed a novel method to induce and stabilize naïve human PSCs that consists in the simple addition of a chemical inhibitor for the closely related CDK8 and CDK19 kinases (CDK8/19i). Long-term cultured CDK8/19i-naïve human PSCs preserve their normal karyotype and do not show widespread DNA demethylation. Here, we investigate the long-term stability of allele-specific methylation at imprinted loci and the differentiation potency of CDK8/19i-naïve human PSCs. We report that long-term cultured CDK8/19i-naïve human PSCs retain the imprinting profile of their parental primed cells, and imprints are further retained upon differentiation in the context of teratoma formation. We have also tested the capacity of long-term cultured CDK8/19i-naïve human PSCs to differentiate into primordial germ cell (PGC)-like cells (PGCLCs) and trophoblast stem cells (TSCs), two cell types that are accessible from the naïve state. Interestingly, long-term cultured CDK8/19i-naïve human PSCs differentiated into PGCLCs with a similar efficiency to their primed counterparts. Also, long-term cultured CDK8/19i-naïve human PSCs were able to differentiate into TSCs, a transition that was not possible for primed PSCs. We conclude that inhibition of CDK8/19 stabilizes human PSCs in a functional naïve state that preserves imprinting and potency over long-term culture

Creación de un modelo conceptual de ciudad a partir del desarrollo empresarial: Citycompany

El trabajo consiste en la creación de un modelo conceptual de desarrollo económico basado en estrategias de localización de actividad empresarial en centros urbanos, cities, como sistema de rehabilitación integral y sostenible, desde el punto de vista social, urbanístico y comercial. Con el fin de obtener las industrias/servicios más adecuados a las características físicas y recursos específicos de la ciudad partiendo de una nueva concepción urbanística que encaje dentro del núcleo de la ciudad y potencie el conjunto de la misma. El objetivo perseguido en este estudio es la rehabilitación de zonas específicas de las ciudades mediante la implantación de empresas que fomenten sus actividades gracias a la adecuada ubicación en ese entorno de la ciudad y que a su vez potencien el desarrollo del área urbana de influencia. El método a utilizar se basa en la programación web de modelos de localización. Para ello las características del territorio objeto de estudio se seleccionarán en una base de datos de entre todas las posibles que definen un territorio en general y a su vez se definirán también en esta base de datos los diferentes tipos de empresas, que desarrollan su actividad en el interior las cities. Esta base datos seleccionará para cada territorio las empresas específicas para su desarrollo, representándolo gráficamente a través de una aplicación web sobre google maps. Los resultados servirán para mejorar la calidad de vida de los ciudadanos, potenciar el concepto ciudad del siglo XXI gracias a la construcción de nuevos espacios integrados en la ciudad.The work is the creation of a conceptual model based economic development strategies business location in urban centers, cities, and comprehensive rehabilitation system and sustainable from the standpoint of social, urban and commercial. To get the industries / services according to the physical characteristics and resources of the city based on a new urban design that fits into the core of the city and enhance the whole of it. The aim in this study is the rehabilitation of specific areas of cities through the establishment of businesses that promote their activities through the appropriate location in that area of the city and in turn enhance the development of the urban area of influence, improving the quality of life of users of the same. The method used is based on the Web programming tracking models. To do the characteristics of the territory under study will be selected in a database of all the potential to define a territory in general and in turn also be addressed in this database of different types of companies, which operate in the inside the cities. This database will select for each specific business area for development, representing it graphically via a web application on google maps. The results will be used to improve not only the quality of life of citizens but also certain areas of the city helping with your contribution to enhancing the XXI century city concept thanks to the construction of new spaces built in the city.Peer Reviewe

Mecp2-null mice provide new neuronal targets for Rett syndrome

BACKGROUND: Rett syndrome (RTT) is a complex neurological disorder that is one of the most frequent causes of mental retardation in women. A great landmark in research in this field was the discovery of a relationship between the disease and the presence of mutations in the gene that codes for the methyl-CpG binding protein 2 (MeCP2). Currently, MeCP2 is thought to act as a transcriptional repressor that couples DNA methylation and transcriptional silencing. The present study aimed to identify new target genes regulated by Mecp2 in a mouse model of RTT. METHODOLOGY/PRINCIPAL FINDINGS: We have compared the gene expression profiles of wild type (WT) and Mecp2-null (KO) mice in three regions of the brain (cortex, midbrain, and cerebellum) by using cDNA microarrays. The results obtained were confirmed by quantitative real-time PCR. Subsequent chromatin immunoprecipitation assays revealed seven direct target genes of Mecp2 bound in vivo (Fkbp5, Mobp, Plagl1, Ddc, Mllt2h, Eya2, and S100a9), and three overexpressed genes due to an indirect effect of a lack of Mecp2 (Irak1, Prodh and Dlk1). The regions bound by Mecp2 were always methylated, suggesting the involvement of the methyl-CpG binding domain of the protein in the mechanism of interaction. CONCLUSIONS: We identified new genes that are overexpressed in Mecp2-KO mice and are excellent candidate genes for involvement in various features of the neurological disease. Our results demonstrate new targets of MeCP2 and provide us with a better understanding of the underlying mechanisms of RTT

Multi-omic rejuvenation of naturally aged tissues by a single cycle of transient reprogramming

Aging; Epigenetic clocks; PluripotencyEnvelliment; Rellotges epigenètics; PluripotènciaEnvejecimiento; Relojes epigenéticos; PluripotenciaThe expression of the pluripotency factors OCT4, SOX2, KLF4, and MYC (OSKM) can convert somatic differentiated cells into pluripotent stem cells in a process known as reprogramming. Notably, partial and reversible reprogramming does not change cell identity but can reverse markers of aging in cells, improve the capacity of aged mice to repair tissue injuries, and extend longevity in progeroid mice. However, little is known about the mechanisms involved. Here, we have studied changes in the DNA methylome, transcriptome, and metabolome in naturally aged mice subject to a single period of transient OSKM expression. We found that this is sufficient to reverse DNA methylation changes that occur upon aging in the pancreas, liver, spleen, and blood. Similarly, we observed reversion of transcriptional changes, especially regarding biological processes known to change during aging. Finally, some serum metabolites and biomarkers altered with aging were also restored to young levels upon transient reprogramming. These observations indicate that a single period of OSKM expression can drive epigenetic, transcriptomic, and metabolomic changes toward a younger configuration in multiple tissues and in the serum

Deregulation of the imprinted DLK1-DIO3 locus ncRNAs is associated with replicative senescence of human adipose-derived stem cells

Background Human adult adipose-derived stem cells (hADSCs) have become the most promising cell source for regenerative medicine. However the prolonged ex vivo expansion periods required to obtain the necessary therapeutic dose promotes progressive senescence, with the concomitant reduction of their therapeutic potential. Aim and scope A better understanding of the determinants of hADSC senescence is needed to improve biosafety while preserving therapeutic efficiency. Here, we investigated the association between deregulation of the imprinted DLK1-DIO3 region and replicative senescence in hADSC cultures. Methods We compared hADSC cultures at short (P S ) and prolonged (P L ) passages, both in standard and low [O 2 ] (21 and 3%, respectively), in relation to replicative senescence. hADSCs were evaluated for expression alterations in the DLK1-DIO3 region on chromosome 14q32, and particularly in its main miRNA cluster. Results Comparison of hADSCs cultured at P L or P S surprisingly showed a quite significant fraction (69%) of upregulated miRNAs in P L cultures mapping to the imprinted 14q32 locus, the largest miRNA cluster described in the genome. In agreement, expression of the lncRNA MEG3 (Maternally Expressed 3; Meg3/Gtl2), cultured at 21 and 3% [O 2 ], was also significantly higher in P L than in P S passages. During hADSC replicative senescence the AcK16H4 activating mark was found to be significantly associated with the deregulation of the entire DLK1-DIO3 locus, with a secondary regulatory role for the methylation of DMR regions. Conclusion A direct relationship between DLK1-DIO3 deregulation and replicative senescence of hADSCs is reported, involving upregulation of a very significant fraction of its largest miRNA cluster (14q32.31), paralleled by the progressive overexpression of the lncRNA MEG3, which plays a central role in the regulation of Dlk1/Dio3 activation status in mice.This work was supported by grants to AB from the Spanish Ministry of Economy, Industry (SAF2015-70882-R; AEI/FEDER, UE), Comunidad Autónoma de Madrid (S2010/BMD-2420), Instituto Salud Carlos III (RETICS TerCel, RD12/0019/0018) and the European Commission (FP7-HEALTH- 2009/CARE-MI). AMS was supported by grants from the MINECO (SAF2010–17167) and Instituto Salud Carlos III (RETICS TerCel, RD12/0019/0013), and MFF and RGU by grants from the Plan Nacional de I+D+I 2013-2016/FEDER (PI15/ 00892), the Asturias Regional Government (GRUPIN14-052), the IUOPA (Obra Social Cajastur) and the Fundación Científica de la AECC. SGL held a predoctoral fellowship from the Spanish Programa de Formación del Profesorado Universitari

Conservation of aging and cancer epigenetic signatures across human and mouse

Aging and cancer are two interrelated processes, with aging being a major risk factor for the development of cancer. Parallel epigenetic alterations have been described for both, although differences, especially within the DNA hypomethylation scenario, have also been recently reported. While many of these observations arise from the use of mouse models, there is a lack of systematic comparisons of human and mouse epigenetic patterns in the context of disease. However, such comparisons are significant as they allow to establish the extent to which some of the observed similarities or differences arise from pre-existing species-specific epigenetic traits. Here, we have used reduced representation bisulfite sequencing to profile the brain methylomes of young and old, tumoral and non-tumoral brain samples from human and mouse. We first characterized the baseline epigenomic patterns of the species and subsequently focused on the DNA methylation alterations associated with cancer and aging. Next, we described the functional genomic and epigenomic context associated with the alterations, and finally we integrated our data to study interspecies DNA methylation levels at orthologous CpG sites. Globally, we found considerable differences between the characteristics of DNA methylation alterations in cancer and aging in both species. Moreover, we describe robust evidence for the conservation of the specific cancer and aging epigenomic signatures in human and mouse. Our observations point towards the preservation of the functional consequences of these alterations at multiple levels of genomic regulation. Finally, our analyses reveal a role for the genomic context in explaining disease- and species-specific epigenetic traits.© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution

DNA methylation map of mouse and human brain identifies target genes in Alzheimer’s disease

The central nervous system has a pattern of gene expression that is closely regulated with respect to functional and anatomical regions. DNA methylation is a major regulator of transcriptional activity, and aberrations in the distribution of this epigenetic mark may be involved in many neurological disorders, such as Alzheimer’s disease. Herein, we have analysed 12 distinct mouse brain regions according to their CpG 5’-end gene methylation patterns and observed their unique epigenetic landscapes. The DNA methylomes obtained from the cerebral cortex were used to identify aberrant DNA methylation changes that occurred in two mouse models of Alzheimer’s disease. We were able to translate these findings to patients with Alzheimer’s disease, identifying DNA methylation-associated silencing of three targets genes: thromboxane A2 receptor (TBXA2R), sorbin and SH3 domain containing 3 (SORBS3) and spectrin beta 4 (SPTBN4). These hypermethylation targets indicate that the cyclic AMP response element-binding protein (CREB) activation pathway and the axon initial segment could contribute to the disease