Laura Batlle-Morera

Bio: Laura Batlle-Morera is an academic researcher from Wellcome Trust Centre for Stem Cell Research. The author has contributed to research in topics: Embryonic stem cell & Cellular differentiation. The author has an hindex of 3, co-authored 3 publications receiving 3124 citations. Previous affiliations of Laura Batlle-Morera include University of Edinburgh.

The ground state of embryonic stem cell self-renewal

Abstract: In the three decades since pluripotent mouse embryonic stem (ES) cells were first described they have been derived and maintained by using various empirical combinations of feeder cells, conditioned media, cytokines, growth factors, hormones, fetal calf serum, and serum extracts. Consequently ES-cell self-renewal is generally considered to be dependent on multifactorial stimulation of dedicated transcriptional circuitries, pre-eminent among which is the activation of STAT3 by cytokines (ref. 8). Here we show, however, that extrinsic stimuli are dispensable for the derivation, propagation and pluripotency of ES cells. Self-renewal is enabled by the elimination of differentiation-inducing signalling from mitogen-activated protein kinase. Additional inhibition of glycogen synthase kinase 3 consolidates biosynthetic capacity and suppresses residual differentiation. Complete bypass of cytokine signalling is confirmed by isolating ES cells genetically devoid of STAT3. These findings reveal that ES cells have an innate programme for self-replication that does not require extrinsic instruction. This property may account for their latent tumorigenicity. The delineation of minimal requirements for self-renewal now provides a defined platform for the precise description and dissection of the pluripotent state.

Parameters influencing derivation of embryonic stem cells from murine embryos.

Abstract: The derivation of ES cells is poorly understood and varies in efficiency between different strains of mice. We have investigated potential differences between embryos of permissive and recalcitrant strains during diapause and ES cell derivation. We found that in diapause embryos of the recalcitrant C57BL/6 and CBA strains, the epiblast failed to expand during the primary explant phase of ES cell derivation, whereas in the permissive 129 strain, it expanded dramatically. Epiblasts from the recalcitrant strains could be expanded by reducing Erk activation. Isolation of 129 epiblasts facilitated very efficient derivation of ES cell lines in serum- and feeder-free conditions, but reduction of Erk activity was required for derivation of ES cells from isolated C57BL/6 or CBA epiblasts. The results suggest that the discrepancy in ES cell derivation efficiency is not attributable merely to variable prodifferentiative effects of the extra-embryonic lineages but also to an intrinsic variability within the epiblast to maintain pluripotency.

Female-specific hyperacetylation of histone H4 in the chicken Z chromosome.

Abstract: Birds undergo genetic sex determination using a ZW sex chromosome system. Although the avian mechanisms of neither sex determination nor dosage compensation are understood, a female-specific non-coding RNA (MHM) is expressed soon after fertilisation from the single Z chicken chromosome and is likely to have a role in one or both processes. We have now discovered a prominent female-specific modification to the Z chromatin in the region of the MHM locus. We find that chicken chromatin at Zp21, including the MHM locus, is strongly enriched for acetylation of histone H4 at lysine residue 16 in female but not male chromosomes. Interestingly, this specific histone modification is also enriched along the length of the up-regulated Drosophila melanogaster male X chromosome where it plays a vital role in the dosage compensation process.

Nuclear MTHFD2 secures mitosis progression by preserving centromere integrity

Abstract: Subcellular compartmentalization of metabolic enzymes may elicit specific cellular functions by establishing a unique metabolic environment. Indeed, the nuclear translocation of certain metabolic enzymes is required for epigenetic regulation and gene expression control. Here, we reveal that, in cancer cells, the mitochondrial enzyme methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) localizes in the nucleus during the G2-M phase of the cell cycle to secure mitosis progression. Nuclear MTHFD2 interacts with proteins involved in mitosis regulation and centromere stability, including the methyltransferases KMT5A and DNMT3B. Loss of MTHFD2 induces centromere overexpression and severe methylation defects and impedes correct mitosis completion. As a consequence, MTHFD2 deficient cells accumulate chromosomal aberrations arising from chromosome congression and segregation defects. Blocking the catalytic nuclear function of MTHFD2 recapitulates the phenotype observed in MTHFD2 deficient cells, attributing to nuclear MTHFD2 an enzymatic active role in controlling mitosis. Our discovery uncovers a nuclear moonlighting role for the cancer target MTHFD2, and emphasizes that cancer metabolism rewiring may encompass the relocation of metabolic enzymes to alternative subcellular compartments.

Hormones and endocrine-disrupting chemicals: Low-dose effects and nonmonotonic dose responses

Abstract: For decades, studies of endocrine-disrupting chemicals (EDCs) have challenged traditional concepts in toxicology, in particular the dogma of “the dose makes the poison,” because EDCs can have effects at low doses that are not predicted by effects at higher doses. Here, we review two major concepts in EDC studies: low dose and nonmonotonicity. Low-dose effects were defined by the National Toxicology Program as those that occur in the range of human exposures or effects observed at doses below those used for traditional toxicological studies. We review the mechanistic data for low-dose effects and use a weight-of-evidence approach to analyze five examples from the EDC literature. Additionally, we explore nonmonotonic dose-response curves, defined as a nonlinear relationship between dose and effect where the slope of the curve changes sign somewhere within the range of doses examined. We provide a detailed discussion of the mechanisms responsible for generating these phenomena, plus hundreds of examples from...

Pluripotent Stem Cells Induced from Mouse Somatic Cells by Small-Molecule Compounds

Abstract: Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource, with potential for studying disease and use in regenerative medicine. However, genetic manipulation and technically challenging strategies such as nuclear transfer used in reprogramming limit their clinical applications. Here, we show that pluripotent stem cells can be generated from mouse somatic cells at a frequency up to 0.2% using a combination of seven small-molecule compounds. The chemically induced pluripotent stem cells resemble embryonic stem cells in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. By using small molecules, exogenous "master genes" are dispensable for cell fate reprogramming. This chemical reprogramming strategy has potential use in generating functional desirable cell types for clinical applications.