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News and perspectives on yolk sac stem cells
Bert Binas 한국수정란이식학회 2016 한국수정란이식학회 학술대회 Vol.2016 No.10
The mammalian yolk sac endoderm is an essential but understudied tissue that patterns and nourishes the embryo. This talk will present the isolation and characterization of several categories of rodent yolk sac endoderm stem cells. Specifically, we have isolated yolk sac endoderm stem cell lines from preimplantation embryos and from post-gastrulation yolk sacs. In both cases, we obtained two versions of stem cells that appear to differ in their degree of lineage maturation. I will discuss the relationship of these various isolates within the same species (rat or mouse), between species (rat vs. mouse), and with previously published isolates. I will then discuss potential applications in developmental biotechnology and toxicology as well as the human relevance of this research.
Developmental Potential of Rat Extraembryonic Stem Cells
Galat, Vasiliy,Binas, Bert,Iannaccone, Stephen,Postovit, Lynne-Marie,Debeb, Bisrat G.,Iannaccone, Philip Mary Ann Liebert 2009 STEM CELLS AND DEVELOPMENT Vol.18 No.9
<P>We have previously found that certain stem cells that are derived from rat blastocysts and named extraembryonic endoderm precursor (XEN-P) cells show a unique molecular signature sharing some of the characteristics of embryonic stem cells (ES), trophoblast stem cells (TS), and extraembryonic endoderm stem cells (XEN). These XEN-P cells are positive for AP, SSEA1, Oct4, and Rex1 markers similar to ES cells and also express signature markers of TS-eomesodermin (Eomes) and XEN-Gata6. Here we show that these cells integrate into the visceral and parietal extraembryonic endoderm lineages as well as into the inner cell mass (ICM), the primitive endoderm, and the polar and mural trophectoderm (TE) of cultured embryos. In addition, we find that the XEN-P cells colonize yolk sac and contribute to trophoblast lineages of postimplantation embryos following transfer to surrogate mothers. We also find that the XEN-P cell culture propagates by shedding cell clusters into the media in addition to typical expansion of colonies. Interestingly, the cell cultures exist as mixed populations of two interconvertible phenotypes of flat and round cells with preferential expression of stem cell markers Oct4 and SSEA1 in round cells. We believe these cells represent a metastable stage during ICM cellular segregation. These results are important for developing hypotheses of cell fate plasticity in the ICM and provide a model for the study of development and differentiation along the extraembryonic lineages.</P>
A New Enhancer in the Flanking Region of the Gene Pou5f1
B. Debeb,B. Binas 한양대학교 이학기술연구소 2009 이학기술논문지 Vol.13 No.-
The gene Pou5f1 encodes the transcription factor Oct4 that is essential for establishing and maintaining pluripotency and may also be involved in early embryonic lineage decisions. It was previously shown that two different enhancers drive the transcription of Pou5f1 in pluripotent stem cells while an enhancer driving Pou5f1 in a non-pluripotent cell type has not yet been described. However, we recently found that Oct4 is expressed in non-pluripotent extraembryonic endoderm precursor (XEN-P) celll ines, and we therefore asked whether Pou5fl. uses a distinct enhancer in these cells. Here we describe reporter gene transfection experiments that indeed document the existence of a new enhancer driving Pou5f1 in the XEN-P cells. Our results reveal an additional regulation of Pou5f1 that may be related to non-traditional roles of Oct4.
Metal Oxide Semiconductors as Visible Light Photocatalysts
George Kiriakidis,Vassilios Binas 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.3
Mn-, Co-, and Mn-Co doped TiO2 ternary and quaternary semiconducting powder materialsprepared by using the co-precipitation method and fully characterized by using x-ray diffraction(XRD), scanning electron microscopy-energy dispersive spectroscopy (SEM – EDS) and UV- visiblediffuse reflection spectroscopy were utilized for the photocatalytic degradation of methylene blueunder visible light irradiation. These materials show a red shift and absorption in the visible regiondepending on the dopant type and concentration. These materials have proven to be effective asvisible light photocatalysts.
Kim, Karam,Kim, Hye Jeong,Binas, Bert,Kang, Jin Hyun,Chung, Il Yup Elsevier 2018 Biochemical and biophysical research communication Vol.503 No.2
<P><B>Abstract</B></P> <P>Danger-associated molecular patterns (DAMPs) play a proinflammatory role in the pathogenesis of airway obstructive diseases such as severe asthma and chronic obstructive pulmonary disease. The NLRP3 inflammasome is a cytosolic multiprotein platform that activates the caspase-1 pathway in response to inflammatory stimuli such as DAMPs. ATP and S100 proteins are newly identified DAMPs that accumulate in inflamed airways. We previously demonstrated that S100A8, S100A9, and S100A12 induce production and secretion of MUC5AC, a major mucin in the conducting airway mucosa. The purpose of this study was to determine the involvement of NLRP3 inflammasome in, and the contribution of ATP to, S100 protein-induced MUC5AC production by NCI-H292 mucoepidermoid carcinoma cells. Stimulation with either S100A12 or ATP led to MUC5AC production at comparable levels. Simultaneous treatment with both stimuli resulted in additive increases in NLRP3, active caspase-1, IL-1β, NLRP3/caspase-1 colocalization, and MUC5AC. NLRP3 siRNA or inhibitors of NF-κB, NLRP3 inflammasome oligomerization, or caspase-1 nearly completely inhibited ATP- and S100A12-mediated MUC5AC production. Furthermore, S100A12-as well as ATP-mediated MUC5AC production was almost equally blunted by both nonspecific and specific antagonists of the purinergic receptor P2X7, a principal receptor mediating NLRP3 inflammasome activation by ATP. Thus, these two danger signals contribute to MUC5AC production in airway epithelial cells through overlapping signaling pathways for NLRP3 inflammasome activation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> S100A12 activates NLPR3 inflammasomes to induce MUC5AC production in epithelial cells. </LI> <LI> ATP induces MUC5AC production in a mechanistically similar mode to S100A12. </LI> <LI> S100A12-mediated MUC5AC production involves engagement of ATP. </LI> </UL> </P>
Analysis of SSEA1+ vs. SSEA1- fractions of bulk-cultured XENP cell lines
Minjin Jeong,Kyeng-Won Choi,김승준,김정호,Bert Binas 한국바이오칩학회 2012 BioChip Journal Vol.6 No.1
Previously isolated rat extraembryonic endoderm precursor (XENP) cell lines had been characterized after clonal density plating. The arising colonies had consisted of peripheral XENP cells expressing the surface antigen SSEA1 and the transcription factor Oct4, and inner XENP-derived extraembryonic endoderm cells that were nearly negative for SSEA1 and Oct4. We now sorted bulk-cultured XENP cell lines from two rat strains by FACS into SSEA1+ and SSEA1- populations and compared their expression profiles by microarray and RT-PCR. In the bulk cultures, the SSEA1+ fraction was only slightly enriched for Oct4, and also slightly enriched for the visceral endoderm markers, Dab2 and Ihh. Both fractions expressed vascular-associated mesodermal markers (VE-cadherin, Flk1). Thus, in regular-density XENP cell cultures, SSEA1 is not suitable as a stem cell marker, and the XENP cells appear to undergo partial somatic differentiation.