Jon Schoorlemmer

Instituto Aragonés de Ciencias de la Salud (IACS)

The reprogramming of X-chromosome inactivation during the acquisition of pluripotency in vivo and in vitro is accompanied by the repression of Xist, the trigger of X-inactivation, and the upregulation of its antisense counterpart Tsix. We have shown that key factors supporting pluripotency-Nanog, Oct4 and Sox2-bind within Xist intron 1 in undiffere...

Patients with COVID-19 may develop abnormal inflammatory response, followed in some cases by severe disease and long-lasting syndromes. We show here that in vitro exposure to SARS-CoV-2 activates the expression of the human endogenous retrovirus (HERV) HERV-W proinflammatory envelope protein (ENV) in peripheral blood mononuclear cells from a subset...

Yin Yang 2 encodes a mammalian-specific transcription factor (YY2) that shares high homology in the zinc finger region with both YY1 and REX1/ZFP42, encoded by the Yin Yang 1 and Reduced Expression Protein 1/Zinc Finger Protein 42 gene, respectively. In contrast to the well-established roles of the latter two in gene regulation, X chromosome inacti...

Aim: The aim of this study was to determine if alterations in DNA methylation in the human placenta would support suspected preterm labor as a pathologic insult associated with diminished placental health. Methods: We evaluated placental DNA methylation at seven loci differentially methylated in placental pathologies using targeted bisulfite sequen...

Post-coronavirus disease condition (PCC) continues to affect many people globally, yet there remains a lack of diagnostic biomarkers to distinguish PCC from those recovered from acute COVID-19. This study compared biomarkers between two age- and gender-matched groups: PCC individuals and those recovered within three months of acute COVID-19 in 2020...

Retroviral reverse transcriptase activity and the increased expression of human endogenous retroviruses (HERVs) are associated with amyotrophic lateral sclerosis (ALS). We were interested in confirming HERVK overexpression in the ALS brain, its use as an accessory diagnostic marker for ALS, and its potential interplay with neuroinflammation. Using...

The original SARS-CoV-2 lineages have been replaced by successive variants of concern (VOCs) over time. The aim of this study was to perform an assessment of the placental infection by SARS-CoV-2 according to the predominant variant at the moment of COVID-19 diagnosis. This was a prospective study of SARS-CoV-2-positive pregnant women between March...

The full text of this preprint has been withdrawn by the authors due to author disagreement with the posting of the preprint. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

Introduction: Studies described an increased frequency of hypertensive disorders of pregnancy (HDP) after a COVID-19 episode. There is limited evidence about SARS-CoV-2 viral load in placenta. This study aimed to investigate the relationship between SARS-CoV-2 viral load in the placenta and clinical development of HDP after COVID-19 throughout dif...

Introduction: Studies described an increased frequency of hypertensive disorders of pregnancy after a COVID-19 episode. There is limited evidence about SARS-CoV-2 viral load in placenta. This study aimed to investigate the relationship between SARS-CoV-2 viral load in placenta and clinical development of HDP after COVID-19 throughout different peri...

Introduction: The incidence of intrauterine growth restriction (IUGR) is estimated at about 3% of pregnancies, and it is associated with 30% of all perinatal mortality and severe morbidity with adverse neurodevelopmental and cardiovascular health consequences in adult life. Early onset IUGR represents 20%-30% of all cases and is highly associated...

Objectives: To determine the role of maternal stress in sub-optimal fetal growth and its relation with RNA expression and DNA methylation of the placental 11β-HSD2. Methods: Prospective cohort study in full-term singleton gestations. Perceived Stress Scale (PSS) was assessed in pregnancies with suspected sub-optimal fetal growth that subsequently d...

Introduction Suspected preterm labour occurs in around 9% of pregnancies. However, almost two-thirds of women admitted for threatened preterm labour ultimately deliver at term and are considered risk-free for fetal development. Methods We examined placental and umbilical cord blood samples from preterm or term deliveries after threatened preterm l...

Background: Yin Yang 2 (YY2) is a zinc finger protein closely related to the well-characterized Yin Yang 1 (YY1). YY1 is a DNA-binding transcription factor, with defined functions in multiple developmental processes, such as implantation, cell differentiation, X inactivation, imprinting and organogenesis. Yy2 has been treated as a largely immateri...

About half of the mammalian genome is occupied by DNA sequences that originate from transposable elements. Retrotransposons can modulate gene expression in different ways and, particularly retrotransposon-derived long terminal repeats, profoundly shape expression of both surrounding and distant genomic loci. This is especially important in pre-impl...

Rex1/Zfp42 is a nuclear protein that is highly conserved in mammals, and widely used as an embryonic stem (ES) cell marker. Although Rex1 expression is associated with enhanced pluripotency, loss-of-function models recently described do not exhibit major phenotypes, and both preimplantation development and ES cell derivation appear normal in the ab...

Rex1/Zfp42 is a Yy1-related zinc-finger protein whose expression is frequently used to identify pluripotent stem cells. We show that depletion of Rex1 levels notably affected self-renewal of mouse embryonic stem (ES) cells in clonal assays, in the absence of evident differences in expression of marker genes for pluripotency or differentiation. By c...

The early embryo harbors the most amazing cells, the embryonic stem (ES) cells, pluripotent cells capable of generating all the tissues and cell types of a mature animal. Discovery and establishment of culture techniques able to maintain in culture human embryonic stem cells revolutionized the scientific community about a decade ago. In addition to...

Background Expression of the Yyl-related zinc finger protein Rex1 is restricted to primary spermatocytes, the preimplantation embryo and various types of pluripotent cells in culture. In line with its association to more pluripotent subpopulations, it is widely used as a marker for embryonic stem cells. Rex1 has been reported to regulate Tsix expre...

Rex-1/Zfp42 displays a remarkably restricted pattern of expression in preimplantation embryos, primary spermatocytes, and undifferentiated mouse embryonic stem (ES) cells and is frequently used as a marker gene for pluripotent stem cells. To understand the role of Rex-1 in selfrenewal and pluripotency, we used Rex-1 association as a measure to iden...

Neurons integrate and encode complex synaptic inputs into action potential outputs through a process termed "intrinsic excitability." Here, we report the essential contribution of fibroblast growth factor homologous factors (FHFs), a family of voltage-gated sodium channel binding proteins, to this process. Fhf1-/-Fhf4-/- mice suffer from severe ata...

Loss of sensory function leads to atrophy or death within the developing CNS, yet little is known about the physiology of remaining synapses. After bilateral deafening, gramicidin-perforated-patch recordings were obtained from gerbil inferior colliculus neurons in a brain slice preparation. Afferent-evoked IPSPs had a diminished ability to block cu...

Fibroblast growth factor homologous factors (FHFs) form native intracellular complexes with the mitogen-activated protein kinase (MAPK) scaffold protein islet-brain 2 (IB2) in adult brain. FHF binding to IB2 facilitates recruitment of the MAPK p38δ (SAPK4), while failing to stimulate binding of JNK, the preferred kinase of the related scaffold IB1...

Supplement to: Fibroblast growth factor homologous factors are intracellular signaling proteins

Fibroblast growth factors (FGFs) mediate cell growth, differentiation, migration, and morphogenesis by binding to the extracellular domain of cell surface receptors, triggering receptor tyrosine phosphorylation and signal transduction [1-5]. FGF homologous factors (FHFs) were discovered within vertebrate DNA sequence databases by virtue of their se...

The products of the Polycomb group (PcG) of genes act as transcriptional repressors involved in the maintenance of homeotic gene expression patterns throughout development, from flies to mice. Biochemical and molecular evidence suggests that the mouse Ring1A gene is a member of the PcG of genes. However, genetic evidence is needed to establish PcG...

In Drosophila, the products of the Polycomb group (Pc-G) of genes act as chromatin-associated multimeric protein complexes that repress expression of homeotic genes. Vertebrate Pc-G homologues have been identified, but the nature of the complexes they form and the mechanisms of their action are largely unknown. The Polycomb homologue M33 is implica...

The stem cell-specific factor Oct-4 is expressed in undifferentiated embryonal carcinoma and embryonic stem cells and is quickly down regulated upon RA-induced differentiation. Irrespective of the direction of differentiation, Oct-4 repression in P19 EC cells requires treatment with high doses of either all-trans or 9-cis RA. Unlike in P19 cells, n...

We have isolated the murine homologs of the members of the COUP-family of steroid hormone receptors, COUP-TF1, ARP-1 and EAR2. The proteins encoded by the murine genes appeared to be highly conserved when compared to their human counterparts. The expression of COUP-TF1 and ARP-1 was induced during differentiation of P19 embryonal carcinoma (EC) cel...

Expression of Oct4 in embryonic stem cells is controlled by a distal upstream stem cell-specific enhancer that is deactivated during retinoic acid (RA)-induced differentiation by an indirect mechanism not involving binding of RA receptors (H. Okazawa, K. Okamoto, F. Ishino, T. Ishino-Kaneko, S. Takeda, Y. Toyoda, M. Muramatsu, and H. Hamada, EMBO J...

Expression of kFGF, which belongs to the family of fibroblast growth factor genes, is restricted to undifferentiated embryonal carcinoma and embryonic stem cells. Stem cell specific expression of kFGF is controlled by a distally localized enhancer, conferring both positive and negative regulation to the kFGF and tk promoters. This enhancer contains...

Embryonic stem (ES) cells, derived in culture directly from the inner cells mass (ICM) of blastocysts, more closely resemble their embryonic counterparts than the more commonly used embryonal carcinoma (EC) cells derived from teratocarcinomas. In view of the potential role of growth factors in early development, we have now followed changes in the...

The jun and fos gene families encode DNA binding proteins involved in transcriptional regulation of genes containing a TPA responsive element (TRE). To study their role in gene regulation during early mammalian development, expression and transcription regulatory properties of their gene products were investigated during retinoic acid (RA) induced...