PubMed | Andalusian Center for Molecular Biology and Regenerative Medicine, Tumour Suppression Group and University of Seville
Type: | Journal: Stem cell reports | Year: 2017
Acquired genomic instability is one of the major concerns for the clinical use of induced pluripotent stem cells (iPSCs). All reprogramming methods are accompanied by the induction of DNA damage, of which double-strand breaks are the most cytotoxic and mutagenic. Consequently, DNA repair genes seem to be relevant for accurate reprogramming to minimize the impact of such DNA damage. Here, we reveal that reprogramming is associated with high levels of DNA end resection, a critical step in homologous recombination. Moreover, the resection factor CtIP is essential for cell reprogramming and establishment of iPSCs, probably to repair reprogramming-induced DNA damage. Our data reveal a new role for DNA end resection in maintaining genomic stability during cell reprogramming, allowing DNA repair fidelity to be retained in both human and mouse iPSCs. Moreover, we demonstrate that reprogramming in a resection-defective environment has long-term consequences on stem cell self-renewal and differentiation.
Galvez P.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Clares B.,University of Granada |
Hmadcha A.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Hmadcha A.,CIBER ISCIII |
And 3 more authors.
British Medical Bulletin | Year: 2013
IntroductionNew therapies with genes, tissues and cells have taken the emerging field for the treatment of many diseases. Advances on stem cell therapy research have led to international regulatory agencies to harmonize and regulate the development of new medicines with stem cells.Sources of dataEuropean Medicines Agency on September 15, 2012.Areas of agreementCell therapy medicinal products should be subjected to the same regulatory principles than any other medicine.Areas of controversyTheir technical requirements for quality, safety and efficacy must be more specific and stringent than other biologic products and medicines.Growing pointsCell therapy medicinal products are at the cutting edge of innovation and offer a major hope for various diseases for which there are limited or no therapeutic options.Areas timely for developing researchThe development of cell therapy medicinal products constitutes an alternative therapeutic strategy to conventional clinical therapy, for which no effective cure was previously available. © 2012 Published by Oxford University Press. All rights reserved.
Lorenzo P.I.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Jimenez Moreno C.M.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Delgado I.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Cobo-Vuilleumier N.,Andalusian Center for Molecular Biology and Regenerative Medicine |
And 6 more authors.
Histochemistry and Cell Biology | Year: 2011
The paired box transcription factor Pax8 is critical for development of the eye, thyroid gland as well as the urinary and reproductive organs. In adult, Pax8 overexpression is associated with kidney, ovarian and thyroid tumors and has emerged as a specific marker for these cancers. Recently, Pax8 expression was also reported in human pancreatic islets and in neuroendocrine tumors, identifying Pax8 as a novel member of the Pax family expressed in the pancreas. Herein, we sought to provide a comprehensive analysis of Pax8 expression during pancreogenesis and in adult islets. Immunohistochemical analysis using the most employed Pax8 polyclonal antibody revealed strong nuclear staining in the developing mouse pancreas and in mature human and mouse islets. Astonishingly, Pax8 mRNA in mouse islets was undetectable while human islets exhibited low levels. These discrepancies raised the possibility of antibody crossreactivity. This premise was confirmed by demonstrating that the polyclonal Pax8 antibody also recognized the isletenriched Pax6 protein both by Western blotting and immunohistochemistry. Thus, in islets polyclonal Pax8 staining corresponds mainly to Pax6. In order to circumvent this caveat, a novel Pax8 monoclonal antibody was used to re-evaluate whether Pax8 was indeed expressed in islets. Surprisingly, Pax8 was not detected in neither the developing pancreas or in mature islets. Reappraisal of pancreatic neuroendocrine tumors using this Pax8 monoclonal antibody exhibited no immunostaining as compared to the Pax8 polyclonal antibody. In conclusion, Pax8 is not expressed in the pancreas and cast doubts on the value of Pax8 as a pancreatic neuroendocrine tumor marker. © The Author(s) 2011.
Calvanese V.,CSIC - National Center for Biotechnology |
Lara E.,University of Oviedo |
Suarez-Alvarez B.,Hospital Universitario Central Of Asturias |
Dawud R.A.,University of Sheffield |
And 15 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2010
The longevity-promoting NAD+-dependent class III histone deacetylase Sirtuin 1 (SIRT1) is involved in stem cell function by controlling cell fate decisionand/or byregulatingthe p53-dependent expression of NANOG. We show that SIRT1 is down-regulated precisely during human embryonic stem cell differentiation at both mRNA and protein levels and that the decrease in Sirt1 mRNA is mediated by a molecular pathway that involves the RNA-binding protein HuR and the arginine methyltransferase coactivator-associated arginine methyltransferase 1 (CARM1). SIRT1 down-regulation leads to reactivation of key developmentalgenes such as the neuroretinalmorphogenesis effectors DLL4, TBX3, and PAX6, which are epigenetically repressed by this histone deacetylase in pluripotent human embryonic stem cells. Our results indicate that SIRT1 is regulated during stem cell differentiation in the context of a yet-unknown epigenetic pathway that controls specific developmental genes in embryonic stem cells.
Bedoya F.J.,Pablo De Olavide University |
Salguero-Aranda C.,Pablo De Olavide University |
Cahuana G.M.,Pablo De Olavide University |
Tapia-Limonchi R.,Andalusian Center for Molecular Biology and Regenerative Medicine |
And 2 more authors.
Islets | Year: 2012
The reduction of pancreatic β-cell mass is an important factor in the development of type 1 and type 2 diabetes. Understanding the mechanisms that regulate the maintenance of pancreatic β-cell mass as well as β-cell death is necessary for the establishment of therapeutic strategies. In this context, nitric oxide (NO) is a diatomic, gaseous, highly reactive molecule with biological activity that participates in the regulation of pancreatic β-cell mass. Two types of cellular responses can be distinguished depending on the level of NO production. First, pancreatic β-cells exposed to inflammatory cytokines, lipid stress or hyperglycaemia produce high concentrations of NO, mainly due to the activation of inducible NO synthase (iNOS), thus promoting cell death. Meanwhile, under homeostatic conditions, low concentrations of NO, constitutively produced by endothelial NO synthase (eNOS), promote cell survival. Here, we will discuss the current knowledge of the NO-dependent mechanisms activated during cellular responses, emphasizing those related to the regulation of cell survival. ©2012 Landes Bioscience.
Ramos-Mejia V.,University of Granada |
Bueno C.,University of Granada |
Roldan M.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Roldan M.,Hospital Virgen Of La Victoria |
And 5 more authors.
Stem Cells and Development | Year: 2012
The mitochondrial contribution to the maintenance of human embryonic stem cell (hESC) pluripotency and culture homeostasis remains poorly understood. Here, we sought to determine whether hESC adaptation to different feeder-free culture conditions is linked to a mitochondrial adaptation. The expression of ESC pluripotency factors and parameters of mitochondrial contribution including mitochondrial membrane potential, mtDNA content, and the expression of master mitochondrial genes implicated in replication, transcription, and biogenesis were determined in 8 hESC lines maintained in 2 distinct human feeders-conditioned media (CM): human foreskin fibroblast-CM (HFF-CM) and mesenchymal stem cell-CM (MSC-CM). We show a robust parallel trend between the expression of ESC pluripotency factors and the mitochondrial contribution depending on the culture conditions employed to maintain the hESCs, with those in MSC-CM consistently displaying increased levels of pluripotency markers associated to an enhanced mitochondrial contribution. The differences in the mitochondrial status between hESCs maintained in MSC-CM versus HFF-CM respond to coordinated changes in mitochondrial gene expression and biogenesis. Importantly, the culture conditions determine the mitochondrial distribution within the stage-specific embryonic antigen 3 positive (SSEA3 +) and negative (SSEA3 -) isolated cell subsets. hESC colonies in MSC-CM display an "intrinsic" high mitochondrial status which may suffice to support undifferentiated growth, whereas hESC colonies maintained in HFF-CM show low mitochondrial status, possibly relying on the production of autologous niche with higher mitochondrial status to support pluripotency and culture homeostasis. Pluripotency markers and mitochondrial status are concomitantly reverted on changing the culture conditions, supporting an unrecognized role of the mitochondria in response to hESC culture adaptation. We provide the first evidence supporting that hESCs adaptation to different feeder-free culture systems relies on a mitochondrial response. © Copyright 2012, Mary Ann Liebert, Inc.
Lachaud C.C.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Pezzolla D.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Dominguez-Rodriguez A.,Institute Biomedicina Of Seville Fisiopatologia Cardiovascular |
Smani T.,Institute Biomedicina Of Seville Fisiopatologia Cardiovascular |
And 4 more authors.
PLoS ONE | Year: 2013
In mammalian visceral organs, vascular smooth muscle cells (VSMCs) originate from an epithelial-to-mesenchymal transition (EMT) of embryonic mesothelial cells (MCs). The ability of adult MCs to recapitulate EMT and to acquire smooth muscle (SM) markers upon provasculogenic culture suggested they might retain embryonic vasculogenic differentiation potential. However, it remains unknown whether adult MCs-derived SM-like cells may acquire specific vascular SM lineage markers and the functionality of differentiated contractile VSMCs. Here, we describe how a gentle trypsinization of adult mouse uterine cords could selectively detach their outermost uterine mesothelial layer cells. As other MCs; uterine MCs (UtMCs) uniformly expressed the epithelial markers β-catenin, ZO-1, E-cadherin, CD54, CD29, and CK18. When cultured in a modified SM differentiation media (SMDM) UtMCs initiated a loss of epithelial characteristics and gained markers expression of EMT (Twist, Snail, and Slug), stem and progenitor (Nanog, Sox2, C-kit, Gata-4, Isl-1, and nestin), SM (α-SMA, calponin, caldesmon, SM22α, desmin, SM-MHC, and smoothelin-B) and cardiac (BMP2, BMP4, ACTC1, sACTN, cTnI, cTnT, ANF, Cx43, and MLC2a). UtMCs repeatedly subcultured in SMDM acquired differentiated VSM-like characteristics and expressed smoothelin-B in the typical stress-fiber pattern expression of contractile VSMCs. Relevantly, UtMCs-derived VSM-like cells could generate "mechanical force" to compact collagen lattices and displayed in diverse degree voltage (K+) and receptor (endothelin-1, oxytocin, norepinephrine, carbachol and vasopressin)-induced [Ca2+]i rises and contraction. Thus, we show for the first time that UtMCs could recapitulate in vitro differentiative events of early cardiovascular differentiation and transdifferentiate in cells exhibiting molecular and functional characteristics of VSMCs. © 2013 Lachaud et al.
Mora-Castilla S.,Pablo De Olavide University |
Tejedo J.R.,Pablo De Olavide University |
Hmadcha A.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Cahuana G.M.,Pablo De Olavide University |
And 3 more authors.
Cell Death and Differentiation | Year: 2010
Exposure of mouse embryonic stem (mES) cells to high concentrations of chemical nitric oxide (NO) donors promotes differentiation, but the mechanisms involved in this process at the gene expression level are poorly defined. In this study we report that culture of mES cells in the presence of 0.25-1.0 mM diethylenetriamine nitric oxide adduct (DETA-NO) leads to downregulation of Nanog and Oct4, the two master genes involved in the control of the pluripotent state. This action of NO was also apparent in the human ES cell line, HS 181. The suppressive action of NO on Nanog gene depends on the activation of p53 repressor protein by covalent modifications, such as pSer15, pSer315, pSer392 and acetyl Lys 379. NO-induced repression of Nanog is also associated with binding of trimethylated histone H3 and pSer315 p53 to its promoter region. In addition, exposure to 0.5 mM DETA-NO induces early differentiation events of cells with acquisition of epithelial morphology and expression of markers of definitive endoderm, such as FoxA2, Gata4, Hfn1-Β and Sox 17. This phenotype was increased when cells were treated with valproic acid (VPA) for 10 days. © 2010 Macmillan Publishers Limited All rights reserved.
Rios-Marco P.,University of Granada |
Martin-Fernandez M.,University of Granada |
Soria-Bretones I.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Rios A.,University of Granada |
And 2 more authors.
Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids | Year: 2013
Glioblastoma is the most common malignant primary brain tumour in adults and one of the most lethal of all cancers. Growing evidence suggests that human tumours undergo abnormal lipid metabolism, characterised by an alteration in the mechanisms that regulate cholesterol homeostasis. We have investigated the effect that different antitumoural alkylphospholipids (APLs) exert upon cholesterol metabolism in the U-87 MG glioblastoma cell line. APLs altered cholesterol homeostasis by interfering with its transport from the plasma membrane to the endoplasmic reticulum(ER), thus hindering its esterification. At the same time they stimulated the synthesis of cholesterol from radiolabelled acetate and its internalisation from low-density lipoproteins (LDLs), inducing both 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) and LDL receptor (LDLR) genes. Fluorescent microscopy revealed that these effects promoted the accumulation of intracellular cholesterol. Filipin staining demonstrated that this accumulation was not confined to the late endosome/lysosome (LE/LY) compartment since it did not colocalise with LAMP2 lysosomal marker. Furthermore, APLs inhibited cell growth, producing arrest at the G2/M phase. We also used transmission electron microscopy (TEM) to investigate ultrastructural alterations induced by APLs and found an abundant presence of autophagic vesicles and autolysosomes in treated cells, indicating the induction of autophagy. Thus our findings clearly demonstrate that antitumoural APLs interfere with the proliferation of the glioblastoma cell line via a complex mechanism involving cholesterol metabolism, cell-cycle arrest or autophagy. Knowledge of the interrelationship between these processes is fundamental to our understanding of tumoural response and may facilitate the development of novel therapeutics to improve treatment of glioblastoma and other types of cancer. © 2013 Elsevier B.V.
Munoz-Barrera M.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Munoz-Barrera M.,Spanish National Research Council |
Monje-Casas F.,Andalusian Center for Molecular Biology and Regenerative Medicine |
Monje-Casas F.,University of SevilleSeville
Proceedings of the National Academy of Sciences of the United States of America | Year: 2014
Aurora B kinase regulates the proper biorientation of sister chromatids during mitosis. Lack of Aurora B kinase function results in the inability to correct erroneous kinetochore-microtubule attachments and gives rise to aneuploidy. Interestingly, increased Aurora B activity also leads to problems with chromosome segregation, and overexpression of this kinase has been observed in various types of cancer. However, little is known about the mechanisms by which an increase in Aurora B kinase activity can impair mitotic progression and cell viability. Here, using a yeast model, we demonstrate that increased Aurora B activity as a result of the overexpression of the Aurora B and inner centromere protein homologs triggers defects in chromosome segregation by promoting the continuous disruption of chromosome-microtubule attachments even when sister chromatids are correctly bioriented. This disruption leads to a constitutive activation of the spindle-assembly checkpoint, which therefore causes a lack of cytokinesis even though spindle elongation and chromosome segregation take place. Finally, we demonstrate that this increase in Aurora B activity causes premature collapse of the mitotic spindle by promoting instability of the spindle midzone.