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Nguyen PNN, Choo KB, Huang CJ, Sugii S, Cheong SK, Kamarul T. miR-524-5p of the primate-specific C19MC miRNA cluster targets TP53IPN1- and EMT-associated genes to regulate cellular reprogramming. Stem Cell Res Ther 2017; 8:214. [PMID: 28962647 PMCID: PMC5622517 DOI: 10.1186/s13287-017-0666-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 08/29/2017] [Accepted: 09/12/2017] [Indexed: 12/26/2022] Open
Abstract
Background Introduction of the transcription factors Oct4, Sox2, Klf4, and c-Myc (OSKM) is able to ‘reprogram’ somatic cells to become induced pluripotent stem cells (iPSCs). Several microRNAs (miRNAs) are known to enhance reprogramming efficiency when co-expressed with the OSKM factors. The primate-specific chromosome 19 miRNA cluster (C19MC) is essential in primate reproduction, development, and differentiation. miR-524-5p, a C19MC member, is highly homologous to the reprogramming miR-520d-5p; we also reported that miR-524-5p was expressed in iPSCs but not mesenchymal stem cells (MSCs). This study aimed to elucidate possible contributions of miR-524-5p to the reprogramming process. Methods A miR-524-5p precursor was introduced into human fibroblast HFF-1 in the presence of OSKM, and the relative number of embryonic stem cell (ESC)-like colonies that stained positively with alkaline phosphatase (AP) and Nanog were quantified to determine reprogramming efficiency. A miR-524-5p mimic was transfected to MSCs to investigate the effects of miR-524-5p on TP53INP1, ZEB2, and SMAD4 expression by real-time polymerase chain reaction (PCR) and Western blot. Direct gene targeting was confirmed by luciferase activity. A phylogenetic tree of TP53INP1 was constructed by the Clustal method. Contribution of miR-524-5p to cell proliferation and apoptosis was examined by cell counts, BrdU, MTT, and cell death assays, and pluripotency gene expression by real-time PCR. Results Co-expressing the miR-524 precursor with OSKM resulted in a two-fold significant increase in the number of AP- and Nanog-positive ESC-like colonies, indicating a role for miR-524-5p in reprogramming. The putative target, TP53INP1, showed an inverse expression relationship with miR-524-5p; direct TP53INP1 targeting was confirmed in luciferase assays. miR-524-5p-induced TP53INP1 downregulation enhanced cell proliferation, suppressed apoptosis, and upregulated the expression of pluripotency genes, all of which are critical early events of the reprogramming process. Interestingly, the TP53INP1 gene may have co-evolved late with the primate-specific miR-524-5p. miR-524-5p also promoted mesenchymal-to-epithelial transition (MET), a required initial event of reprogramming, by directly targeting the epithelial-to-mesenchymal transition (EMT)-related genes, ZEB2 and SMAD4. Conclusions Via targeting TP53INP1, ZEB2, and SMAD4, miR-524-5p contributes to the early stage of inducing pluripotency by promoting cell proliferation, inhibiting apoptosis, upregulating expression of pluripotency genes, and enhancing MET. Other C19MC miRNAs may have similar reprogramming functions. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0666-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Phan Nguyen Nhi Nguyen
- Centre for Stem Cell Research, Universiti Tunku Abdul Rahman, Sungai Long, Kajang, Selangor DE, Malaysia.,Department of Preclinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Sungai Long Campus, Bandar Sungai Long, Cheras, 43000, Kajang, Selangor DE, Malaysia
| | - Kong Bung Choo
- Centre for Stem Cell Research, Universiti Tunku Abdul Rahman, Sungai Long, Kajang, Selangor DE, Malaysia. .,Department of Preclinical Sciences, Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Sungai Long Campus, Bandar Sungai Long, Cheras, 43000, Kajang, Selangor DE, Malaysia.
| | - Chiu-Jung Huang
- Department of Animal Science, Chinese Culture University, Taipei, Taiwan.,Graduate Institute of Biotechnology, Chinese Culture University, Taipei, Taiwan
| | - Shigeki Sugii
- Singapore BioImaging Consortium A*Star, Singapore, Singapore.,Duke-NUS Graduate Medical School, Singapore, Singapore
| | - Soon Keng Cheong
- Centre for Stem Cell Research, Universiti Tunku Abdul Rahman, Sungai Long, Kajang, Selangor DE, Malaysia.,Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Sungai Long, Kajang, Selangor DE, Malaysia
| | - Tunku Kamarul
- Tissue Engineering Group, National Orthopaedic Centre of Excellence for Research and Learning, Kuala Lumpur, Malaysia.,Department of Orthopaedic Surgery, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Emergence of undifferentiated colonies from mouse embryonic stem cells undergoing differentiation by retinoic acid treatment. In Vitro Cell Dev Biol Anim 2016; 52:616-24. [PMID: 27130680 DOI: 10.1007/s11626-016-0013-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 02/24/2016] [Indexed: 10/21/2022]
Abstract
Retinoic acid (RA) is one of the most potent inducers of differentiation of mouse embryonic stem cells (ESCs). However, previous studies show that RA treatment of cells cultured in the presence of a leukemia inhibitory factor (LIF) also result in the upregulation of a gene called Zscan4, whose transient expression is a marker for undifferentiated ESCs. We explored the balance between these two seemingly antagonistic effects of RA. ESCs indeed differentiated in the presence of LIF after RA treatment, but colonies of undifferentiated ESCs eventually emerged from these differentiated cells - even in the presence of RA. These colonies, named secondary colonies, consist of three cell types: typical undifferentiated ESCs expressing pluripotency genes such as Pou5f1, Sox2, and Nanog; cells expressing Zscan4; and endodermal-like cells located at the periphery of the colony. The capacity to form secondary colonies was confirmed for all eight tested ESC lines. Cells from the secondary colonies - after transfer to the standard ESC medium - retained pluripotency, judged by their strong alkaline phosphatase (ALP) staining, typical colony morphology, gene expression profile, stable karyotype, capacity to differentiate into all three germ layers in embryoid body formation assays, and successful contribution to chimeras after injection into blastocysts. Based on flow cytometry analysis (FACS), the proportion of Zscan4-positive cells in secondary colonies was higher than in standard ESC colonies, which may explain the capacity of ESCs to resist the differentiating effects of RA and instead form secondary colonies of undifferentiated ESCs. This hypothesis is supported by cell-lineage tracing analysis, which showed that most cells in the secondary colonies were descendents of cells transiently expressing Zscan4.
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Li Q, Gomez-Lopez N, Drewlo S, Sanchez-Rodriguez E, Dai J, Puscheck EE, Rappolee DA. Development and Validation of a Rex1-RFP Potency Activity Reporter Assay That Quantifies Stress-Forced Potency Loss in Mouse Embryonic Stem Cells. Stem Cells Dev 2016; 25:320-8. [PMID: 26651054 PMCID: PMC4761856 DOI: 10.1089/scd.2015.0169] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 12/03/2015] [Indexed: 11/13/2022] Open
Abstract
Assays for embryonic stem cells (ESCs) of the blastocyst are needed to quantify stress-induced decreases of potent subpopulations. High-throughput screens (HTSs) of stressed ESCs quantify embryonic stress, diminishing laboratory animal needs. Normal or stress-induced ESC differentiation is marked by Rex1 potency factor loss. Potency reporter ESC assays were developed, using low-stress techniques to create transgenic ESCs. Rex1 and Oct4 promoters drove RFP and green fluorescent protein (GFP) expression, respectively. Lentivirus infection and fluorescence-activated cell sorting selection of ESCs obviated the need for stressful electroporation and antibiotic selection, respectively. We showed using immunoblots, microscopic analysis, flow cytometry, and fluorescence microplate reader that the response to stress of potency-reporter ESCs is similar to parental ESCs assayed by biochemical means. Stress caused a dose-dependent decrease in bright Rex1-RFP(+) ESCs and increase in Rex1 dim ESCs. At highest stress, ∼ 20% of bright Rex1-RFP cells are lost coinciding with a 2.8-fold increase in Rex1-RFP dim cells that approach 20%. This conversion of bright to dim cells tested by flow cytometry is commensurate with about 60% loss in fluorescence measured by microplate reader. Dose-dependent stress-induced Rex1-RFP and endogenous Rex1 protein decreases are similar. The data show that Rex1 reporter ESCs accurately report stress in a microplate reader-based HTS. The increasing dim Rex1 subpopulation size is balanced by the decreasing total ESC number during culture at multiple sorbitol doses. This is consistent with previous observations that stress forces potency decrease and differentiation increase to compensate for stress-induced diminished stem cell population growth.
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Affiliation(s)
- Quanwen Li
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
- Program for Reproductive Sciences, Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Nardhy Gomez-Lopez
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
| | - Sascha Drewlo
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
| | - Elly Sanchez-Rodriguez
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
| | - Jing Dai
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
| | - Elizabeth E. Puscheck
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
| | - Daniel A. Rappolee
- Department of Ob/Gyn, Reproductive Endocrinology and Infertility, CS Mott Center for Human Growth and Development, Wayne State University School of Medicine, Detroit, Michigan
- Program for Reproductive Sciences, Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
- Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, Michigan
- Institutes for Environmental Health Science, Wayne State University School of Medicine, Detroit, Michigan
- Department of Biology, University of Windsor, Windsor, Canada
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Vishwakarma SK, Bardia A, Tiwari SK, Paspala SA, Khan AA. Current concept in neural regeneration research: NSCs isolation, characterization and transplantation in various neurodegenerative diseases and stroke: A review. J Adv Res 2014; 5:277-94. [PMID: 25685495 PMCID: PMC4294738 DOI: 10.1016/j.jare.2013.04.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 04/10/2013] [Accepted: 04/28/2013] [Indexed: 12/14/2022] Open
Abstract
Since last few years, an impressive amount of data has been generated regarding the basic in vitro and in vivo biology of neural stem cells (NSCs) and there is much far hope for the success in cell replacement therapies for several human neurodegenerative diseases and stroke. The discovery of adult neurogenesis (the endogenous production of new neurons) in the mammalian brain more than 40 years ago has resulted in a wealth of knowledge about stem cells biology in neuroscience research. Various studies have done in search of a suitable source for NSCs which could be used in animal models to understand the basic and transplantation biology before treating to human. The difficulties in isolating pure population of NSCs limit the study of neural stem behavior and factors that regulate them. Several studies on human fetal brain and spinal cord derived NSCs in animal models have shown some interesting results for cell replacement therapies in many neurodegenerative diseases and stroke models. Also the methods and conditions used for in vitro culture of these cells provide an important base for their applicability and specificity in a definite target of the disease. Various important developments and modifications have been made in stem cells research which is needed to be more specified and enrolment in clinical studies using advanced approaches. This review explains about the current perspectives and suitable sources for NSCs isolation, characterization, in vitro proliferation and their use in cell replacement therapies for the treatment of various neurodegenerative diseases and strokes.
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Affiliation(s)
- Sandeep K. Vishwakarma
- Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, 500 058 Andhra Pradesh, India
- Paspala Advanced Neural (PAN) Research Foundation, Narayanguda, Hyderabad, 500 029 Andhra Pradesh, India
| | - Avinash Bardia
- Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, 500 058 Andhra Pradesh, India
| | - Santosh K. Tiwari
- Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, 500 058 Andhra Pradesh, India
| | - Syed A.B. Paspala
- Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, 500 058 Andhra Pradesh, India
- Paspala Advanced Neural (PAN) Research Foundation, Narayanguda, Hyderabad, 500 029 Andhra Pradesh, India
| | - Aleem A. Khan
- Centre for Liver Research and Diagnostics, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, 500 058 Andhra Pradesh, India
- Paspala Advanced Neural (PAN) Research Foundation, Narayanguda, Hyderabad, 500 029 Andhra Pradesh, India
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Lee KC, Wong WK, Feng B. Decoding the Pluripotency Network: The Emergence of New Transcription Factors. Biomedicines 2013; 1:49-78. [PMID: 28548056 PMCID: PMC5423462 DOI: 10.3390/biomedicines1010049] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/10/2013] [Accepted: 12/11/2013] [Indexed: 12/25/2022] Open
Abstract
Since the successful isolation of mouse and human embryonic stem cells (ESCs) in the past decades, massive investigations have been conducted to dissect the pluripotency network that governs the ability of these cells to differentiate into all cell types. Beside the core Oct4-Sox2-Nanog circuitry, accumulating regulators, including transcription factors, epigenetic modifiers, microRNA and signaling molecules have also been found to play important roles in preserving pluripotency. Among the various regulations that orchestrate the cellular pluripotency program, transcriptional regulation is situated in the central position and appears to be dominant over other regulatory controls. In this review, we would like to summarize the recent advancements in the accumulating findings of new transcription factors that play a critical role in controlling both pluripotency network and ESC identity.
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Affiliation(s)
- Kai Chuen Lee
- Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Room 105A, 1/F, Lo Kwee-Seong Integrated Biomedical Sciences Building, Area 39, Shatin, N.T., Hong Kong, China.
| | - Wing Ki Wong
- Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Room 105A, 1/F, Lo Kwee-Seong Integrated Biomedical Sciences Building, Area 39, Shatin, N.T., Hong Kong, China.
| | - Bo Feng
- Key Laboratory for Regenerative Medicine, Ministry of Education, School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Room 105A, 1/F, Lo Kwee-Seong Integrated Biomedical Sciences Building, Area 39, Shatin, N.T., Hong Kong, China.
- SBS Core Laboratory, Shenzhen Research Institute, the Chinese University of Hong Kong, 4/F CUHK Shenzhen Research Institute Building, No.10, 2nd Yuexing Road, Nanshan District, Shenzhen 518057, China.
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6
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Son MY, Choi H, Han YM, Sook Cho Y. Unveiling the critical role of REX1 in the regulation of human stem cell pluripotency. Stem Cells 2013; 31:2374-87. [DOI: 10.1002/stem.1509] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 07/11/2013] [Accepted: 07/15/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Mi-Young Son
- Stem Cell Research Center; Korea Research Institute of Bioscience and Biotechnology (KRIBB); Daejeon Republic of Korea
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology (KAIST); Daejeon Republic of Korea
| | - Hoonsung Choi
- Stem Cell Research Center; Korea Research Institute of Bioscience and Biotechnology (KRIBB); Daejeon Republic of Korea
| | - Yong-Mahn Han
- Department of Biological Sciences; Korea Advanced Institute of Science and Technology (KAIST); Daejeon Republic of Korea
| | - Yee Sook Cho
- Stem Cell Research Center; Korea Research Institute of Bioscience and Biotechnology (KRIBB); Daejeon Republic of Korea
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7
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Variations in the epigenetic regulation of lineage-specific genes among human pluripotent stem cell lines. Biochem Biophys Res Commun 2012; 424:331-7. [DOI: 10.1016/j.bbrc.2012.06.122] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 06/25/2012] [Indexed: 12/31/2022]
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8
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Rezende NC, Lee MY, Monette S, Mark W, Lu A, Gudas LJ. Rex1 (Zfp42) null mice show impaired testicular function, abnormal testis morphology, and aberrant gene expression. Dev Biol 2011; 356:370-82. [PMID: 21641340 DOI: 10.1016/j.ydbio.2011.05.664] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 05/18/2011] [Accepted: 05/19/2011] [Indexed: 12/27/2022]
Abstract
Rex1 (Zfp42), GeneID 132625, is a gene whose expression is closely associated with pluripotency/multipotency in both mouse and human embryonic stem cells. To study the function of the murine Rex1 gene in vivo, we have used cre/lox technology to create Rex1(floxed) mice and mice deficient in Rex1 gene function. Rex1(-/-)males are characterized by an age-associated decrease in sperm counts, abnormal sperm morphology, and mild testicular atrophy. We characterized global patterns of gene expression in primary germ cells by microarray and identified the growth hormone responsive gene, GRTP1, as a transcript present at a 4.5 fold higher level in wild type (WT) compared to Rex1(-/-) mice. We analyzed immature germ cell (Dazl), proliferating (PCNA), and Sertoli cell populations, and quantitated levels of apoptosis in Rex1(-/-) as compared to WT testes. We evaluated the expression of proteins previously reported to correlate with Rex1 expression, such as STAT3, phospho-STAT3, p38, and phospho-p38 in the testis. We report a distinct cellular localization of total STAT3 protein in Rex1(-/-) affected testes. Our data suggest that loss of Rex1 leads to impaired testicular function.
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Affiliation(s)
- Naira C Rezende
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, USA
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9
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Kim JD, Kim H, Ekram MB, Yu S, Faulk C, Kim J. Rex1/Zfp42 as an epigenetic regulator for genomic imprinting. Hum Mol Genet 2011; 20:1353-62. [PMID: 21233130 DOI: 10.1093/hmg/ddr017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Zfp42/Rex1 (reduced expression gene 1) is a well-known stem-cell marker that has been duplicated from YY1 in the eutherian lineage. In the current study, we characterized the in vivo roles of Rex1 using a mutant mouse line disrupting its transcription. In contrast to the ubiquitous expression of YY1, Rex1 is expressed only during spermatogenesis and early embryogenesis and also in a very limited area of the placenta. Yet, the gene dosage of Rex1 is very critical for the survival of the late-stage embryos and neonates. This delayed phenotypic consequence suggests potential roles for Rex1 in establishing and maintaining unknown epigenetic modifications. Consistently, Rex1-null blastocysts display hypermethylation in the differentially methylated regions (DMRs) of Peg3 and Gnas imprinted domains, which are known to contain YY1 binding sites. Further analyses confirmed in vivo binding of Rex1 only to the unmethylated allele of these two regions. Thus, Rex1 may function as a protector for these DMRs against DNA methylation. Overall, the functional connection of Rex1 to genomic imprinting represents another case where newly made genes have co-evolved with lineage-specific phenomena.
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Affiliation(s)
- Jeong Do Kim
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
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Abstract
Retinoids are ubiquitous signaling molecules that influence nearly every cell type, exert profound effects on development, and complement cancer chemotherapeutic regimens. All-trans retinoic acid (RA) and other active retinoids are generated from vitamin A (retinol), but key aspects of the signaling pathways required to produce active retinoids remain unclear. Retinoids generated by one cell type can affect nearby cells, so retinoids also function in intercellular communication. RA induces differentiation primarily by binding to RARs, transcription factors that associate with RXRs and bind RAREs in the nucleus. Binding of RA: (1) initiates changes in interactions of RAR/RXRs with co-repressor and co-activator proteins, activating transcription of primary target genes; (2) alters interactions with proteins that induce epigenetic changes; (3) induces transcription of genes encoding transcription factors and signaling proteins that further modify gene expression (e.g., FOX03A, Hoxa1, Sox9, TRAIL, UBE2D3); and (4) results in alterations in estrogen receptor α signaling. Proteins that bind at or near RAREs include Sin3a, N-CoR1, PRAME, Trim24, NRIP1, Ajuba, Zfp423, and MN1/TEL. Interactions among retinoids, RARs/RXRs, and these proteins explain in part the powerful effects of retinoids on stem cell differentiation. Studies of this retinol signaling cascade enhance our ability to understand and regulate stem cell differentiation for therapeutic and scientific purposes. In cancer chemotherapeutic regimens retinoids can promote tumor cell differentiation and/or induce proteins that sensitize tumors to drug combinations. Mechanistic studies of retinoid signaling continue to suggest novel drug targets and will improve therapeutic strategies for cancer and other diseases, such as immune-mediated inflammatory diseases.
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Affiliation(s)
- Lorraine J Gudas
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, New York 10065, USA.
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Huang HI, Chen SK, Ling QD, Chien CC, Liu HT, Chan SH. Multilineage differentiation potential of fibroblast-like stromal cells derived from human skin. Tissue Eng Part A 2010; 16:1491-501. [PMID: 20001268 DOI: 10.1089/ten.tea.2009.0431] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Adult stem cells that reside in adult tissues have been deemed to possess great potential for clinical application because of their capabilities of self-renewal and differentiation. However, the limitations such as infection risks and low isolation rate make the search for appropriate source to be continued. Here, we demonstrate isolation of progenitors from human foreskin tissue samples, which have fibroblast-like morphology and could be easily propagated for more than 50 passages. These foreskin-derived fibroblast-like stromal cells (FDSCs) expressed CD90, CD105, CD166, CD73, SH3, and SH4, which is similar to the immunophenotypes of human bone marrow-derived mesenchymal stem cells. In comparison with Hs68, the human fibroblast cell line, FDSCs are positive for CD105 and absent for CD54 expression. Further, FDSCs could be induced to differentiate into osteocytes, adipocytes, neural cells, smooth muscle cells, Schwann-like cells, and hepatocyte-like cells. Interestingly, when cultured in Dulbecco's modified Eagle's medium/F12 medium, FDSCs can form spheres with increased expression levels of fibronectin and vimentin. In conclusion, foreskin can serve as a valuable source of multipotent cells with the capabilities for endodermal, mesodermal, and ectodermal cells. Coupled with the advantages of their easy access, isolation, and propagation, these foreskin-derived stromal cells might be of potential use in future studies in stem cell differentiation and therapeutic application.
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Affiliation(s)
- Hsing-I Huang
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, 259, Wen-Hwa 1st Road, Kwei-Shan Tao-Yuan 221, Taiwan.
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Lee MY, Lu A, Gudas LJ. Transcriptional regulation of Rex1 (zfp42) in normal prostate epithelial cells and prostate cancer cells. J Cell Physiol 2010; 224:17-27. [PMID: 20232320 DOI: 10.1002/jcp.22071] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Rex1 (zfp42) was identified by our laboratory because of its reduced expression in F9 teratocarcinoma stem cells after retinoic acid (RA) treatment. The Rex1 (Zfp42) gene is currently widely used as a marker of embryonic stem cells. We compared the transcriptional regulation of the human Rex1 gene in NTera-2 (NT-2) human teratocarcinoma, normal human prostate epithelial cells (PrEC), and prostate cancer cells (PC-3) by promoter/luciferase analyses. Oct4, Sox2, Nanog, and Dax1 transcripts are expressed at higher levels in NT-2 and PrEC cells than in PC-3 cells. Co-transfection analyses showed that YY1 and Rex1 are positive regulators of hRex1 transcription in NT-2 and PrEC cells, whereas Nanog is not. Serial deletion constructs of the hRex1 promoter were created and analyzed, by which we identified a potential negative regulatory site that is located between -1 and -0.4 kb of the hRex1 promoter. We also delineated regions of the hRex1 promoter between -0.4 kb and the TSS that, when mutated, reduced transcriptional activation; these are putative Rex1 binding sites. Mutation of a putative Rex1 binding site in electrophoretic mobility shift assays (EMSA) resulted in reduced protein binding. Taken together, our results indicate that hRex1 binds to the hRex1 promoter region at -298 bp and positively regulates hRex1 transcription, but that this regulation is lost in PC-3 human prostate cancer cells. This lack of positive transcriptional regulation by the hRex1 protein may be responsible for the lack of Rex1 expression in PC-3 prostate cancer cells.
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Affiliation(s)
- Mi-Young Lee
- Department of Pharmacology, Weill Cornell Medical College of Cornell University, New York, NY 10065, USA
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Zhong JF, Weiner L, Jin Y, Lu W, Taylor CR. A real-time pluripotency reporter for human stem cells. Stem Cells Dev 2010; 19:47-52. [PMID: 19473101 DOI: 10.1089/scd.2008.0363] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pluripotency of stem cells refers to a stem cell that has the potential to differentiate into any of the three germ layers: endoderm, mesoderm, or ectoderm. Maintaining pluripotent stem cells in culture is a tedious and demanding task. Monitoring the changing pluripotency in live cells is essential for this task. Here, we report a pluripotency monitoring system in which the expression of green fluorescent protein (GFP) is under the control of the promoter of a pluripotency gene (Rex-1). The reporter system can be permanently integrated into the genome of live cells via lentiviral vectors. This pluripotency reporter system permits the long-term real-time monitoring of pluripotency changes in a live single cell and its progeny. Our data demonstrate that the BJ cell line (a normal human fibroblast cell line) that carries this hRex-GFP construct does not express GFP until it is reprogrammed to pluripotent stage. The GFP expression was progressively lost when these pluripotent hRex-GFP cells exposed to differentiation conditions. These results indicate that insertion of the hRex-GFP construct is stable in descendant cells, a finding that has particular value in tracking pluripotency of transplanted cells and their progenies in animal studies. With this hRex-GFP reporter, the pluripotency of cells can be monitored over long periods of time via the expression of GFP. Use of this reporter system will facilitate the study of stem cell pluripotency at the single-cell level, and sheds light on the molecular mechanisms of stem cell self-renewal and subsequent differentiation.
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Affiliation(s)
- Jiang F Zhong
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
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Kashyap V, Rezende NC, Scotland KB, Shaffer SM, Persson JL, Gudas LJ, Mongan NP. Regulation of stem cell pluripotency and differentiation involves a mutual regulatory circuit of the NANOG, OCT4, and SOX2 pluripotency transcription factors with polycomb repressive complexes and stem cell microRNAs. Stem Cells Dev 2009; 18:1093-108. [PMID: 19480567 DOI: 10.1089/scd.2009.0113] [Citation(s) in RCA: 327] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Coordinated transcription factor networks have emerged as the master regulatory mechanisms of stem cell pluripotency and differentiation. Many stem cell-specific transcription factors, including the pluripotency transcription factors, OCT4, NANOG, and SOX2 function in combinatorial complexes to regulate the expression of loci, which are involved in embryonic stem (ES) cell pluripotency and cellular differentiation. This review will address how these pathways form a reciprocal regulatory circuit whereby the equilibrium between stem cell self-renewal, proliferation, and differentiation is in perpetual balance. We will discuss how distinct epigenetic repressive pathways involving polycomb complexes, DNA methylation, and microRNAs cooperate to reduce transcriptional noise and to prevent stochastic and aberrant induction of differentiation. We will provide a brief overview of how these networks cooperate to modulate differentiation along hematopoietic and neuronal lineages. Finally, we will describe how aberrant functioning of components of the stem cell regulatory network may contribute to malignant transformation of adult stem cells and the establishment of a "cancer stem cell" phenotype and thereby underlie multiple types of human malignancies.
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Affiliation(s)
- Vasundhra Kashyap
- Department of Pharmacology, Graduate Programs in Pharmacology, Weill Cornell Medical College, New York, New York 10065, USA
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15
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Scotland KB, Chen S, Sylvester R, Gudas LJ. Analysis of Rex1 (zfp42) function in embryonic stem cell differentiation. Dev Dyn 2009; 238:1863-77. [PMID: 19618472 DOI: 10.1002/dvdy.22037] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Rex1 (zfp42) is a zinc finger protein expressed primarily in undifferentiated stem cells, both in the embryo and the adult. Upon all-trans retinoic acid induced differentiation of murine embryonic stem (ES) cells, Rex1 mRNA levels decrease several fold. To characterize the function(s) of Rex1 more extensively, we generated Rex1 double knockout ES cell lines. The disruption of the Rex1 gene enhanced the expression of ectoderm, mesoderm, and endoderm markers as compared to wild-type (Wt) cells. We propose that Rex1 acts to reduce retinoic acid induced differentiation in ES cells. We performed microarray analyses on Wt and Rex1-/- cells cultured in the presence or absence of LIF to identify potential Rex1 targets. We also evaluated gene expression in a Wt line that overexpresses Rex1 and in a Rex1-/- line in which Rex1 expression was restored. These data, taken together, suggest that Rex1 influences differentiation, cell cycle regulation, and cancer progression.
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Affiliation(s)
- Kymora B Scotland
- Department of Pharmacology, Weill Medical College of Cornell University, New York, New York 10065, USA
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16
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Boheler KR. Stem cell pluripotency: a cellular trait that depends on transcription factors, chromatin state and a checkpoint deficient cell cycle. J Cell Physiol 2009; 221:10-7. [PMID: 19562686 PMCID: PMC3326661 DOI: 10.1002/jcp.21866] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Embryonic stem (ES) and induced pluripotent stem (iPS) cells self-renew and are pluripotent. Differentiation of these cells can yield over 200 somatic cell types, making pluripotent cells an obvious source for regenerative medicine. Before the potential of these cells can be maximally harnessed for clinical applications, it will be necessary to understand the processes that maintain pluripotentiality and signal differentiation. Currently, three unique molecular properties distinguish pluripotent stem cells from somatic cells. These include a unique transcriptional hierarchy that sustains the pluripotent state during the process of self-renewal; a poised epigenetic state that maintains chromatin in a form ready for rapid cell fate decisions; and a cell cycle characterized by an extremely short gap 1 (G1) phase and the near absence of normal somatic cell checkpoint controls. Recently, B-MYB (MYBL2) was implicated in the gene regulation of two pluripotency factors and normal cell cycle progression. In this article, the three pluripotency properties and the potential role of B-Myb to regulate these processes will be discussed.
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17
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Kita-Matsuo H, Barcova M, Prigozhina N, Salomonis N, Wei K, Jacot JG, Nelson B, Spiering S, Haverslag R, Kim C, Talantova M, Bajpai R, Calzolari D, Terskikh A, McCulloch AD, Price JH, Conklin BR, Chen HSV, Mercola M. Lentiviral vectors and protocols for creation of stable hESC lines for fluorescent tracking and drug resistance selection of cardiomyocytes. PLoS One 2009; 4:e5046. [PMID: 19352491 PMCID: PMC2662416 DOI: 10.1371/journal.pone.0005046] [Citation(s) in RCA: 196] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 02/17/2009] [Indexed: 01/26/2023] Open
Abstract
Background Developmental, physiological and tissue engineering studies critical to the development of successful myocardial regeneration therapies require new ways to effectively visualize and isolate large numbers of fluorescently labeled, functional cardiomyocytes. Methodology/Principal Findings Here we describe methods for the clonal expansion of engineered hESCs and make available a suite of lentiviral vectors for that combine Blasticidin, Neomycin and Puromycin resistance based drug selection of pure populations of stem cells and cardiomyocytes with ubiquitous or lineage-specific promoters that direct expression of fluorescent proteins to visualize and track cardiomyocytes and their progenitors. The phospho-glycerate kinase (PGK) promoter was used to ubiquitously direct expression of histone-2B fused eGFP and mCherry proteins to the nucleus to monitor DNA content and enable tracking of cell migration and lineage. Vectors with T/Brachyury and α-myosin heavy chain (αMHC) promoters targeted fluorescent or drug-resistance proteins to early mesoderm and cardiomyocytes. The drug selection protocol yielded 96% pure cardiomyocytes that could be cultured for over 4 months. Puromycin-selected cardiomyocytes exhibited a gene expression profile similar to that of adult human cardiomyocytes and generated force and action potentials consistent with normal fetal cardiomyocytes, documenting these parameters in hESC-derived cardiomyocytes and validating that the selected cells retained normal differentiation and function. Conclusion/Significance The protocols, vectors and gene expression data comprise tools to enhance cardiomyocyte production for large-scale applications.
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Affiliation(s)
- Hiroko Kita-Matsuo
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Maria Barcova
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Natalie Prigozhina
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Nathan Salomonis
- Gladstone Institute of Cardiovascular Disease, University of California San Francisco, San Francisco, California, United States of America
| | - Karen Wei
- Burnham Institute for Medical Research, La Jolla, California, United States of America
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
| | - Jeffrey G. Jacot
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
| | - Brandon Nelson
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Sean Spiering
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - René Haverslag
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Changsung Kim
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Maria Talantova
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Ruchi Bajpai
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Diego Calzolari
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Alexey Terskikh
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Andrew D. McCulloch
- Department of Bioengineering, University of California San Diego, La Jolla, California, United States of America
| | - Jeffrey H. Price
- Burnham Institute for Medical Research, La Jolla, California, United States of America
| | - Bruce R. Conklin
- Gladstone Institute of Cardiovascular Disease, University of California San Francisco, San Francisco, California, United States of America
| | - H. S. Vincent Chen
- Burnham Institute for Medical Research, La Jolla, California, United States of America
- Division of Cardiology, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Mark Mercola
- Burnham Institute for Medical Research, La Jolla, California, United States of America
- * E-mail:
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18
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Jiang S, Zhang S, Langenfeld J, Lo SC, Rogers MB. Mycoplasma infection transforms normal lung cells and induces bone morphogenetic protein 2 expression by post-transcriptional mechanisms. J Cell Biochem 2008; 104:580-94. [PMID: 18059017 DOI: 10.1002/jcb.21647] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Bone morphogenetic protein 2 (BMP2) is an essential growth factor and morphogen, whose pattern and level of expression profoundly influences development and physiology. We present the novel finding that mycoplasma infection induces BMP2 RNA production in six cell lines of diverse types (mesenchymal, epithelial, and myeloid). Mycoplasma infection triggered the expression of mature secreted BMP2 protein in BEAS-2B cells (immortalized human bronchial epithelial cells), which normally do not express BMP2, and further increased BMP2 production in A549 cells (lung adenocarcinoma cells). Indeed, mycoplasma is as strong an experimental inducer as inflammatory cytokines and retinoic acid. Second, we showed that post-transcriptional mechanisms including regulation of RNA stability, rather than transcriptional mechanisms, contributed to the increased BMP2 expression in mycoplasma-infected cells. Furthermore, a novel G-rich oligonucleotide, AS1411 that binds the post-transcriptional regulator nucleolin induced BMP2 exclusively in infected cells. Finally, BMP2 stimulated proliferation in BEAS-2B cells transformed by chronic mycoplasma infection, as demonstrated by treatment with Noggin, a BMP2 antagonist. These findings have important implications regarding the effects of mycoplasma on BMP2-regulated processes, including cell proliferation, differentiation, and apoptosis.
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Affiliation(s)
- Shan Jiang
- Department of Biochemistry and Molecular Biology, UMDNJ-NJ Medical School, Newark, New Jersey 07101-1709, USA
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19
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Hsiao EC, Yoshinaga Y, Nguyen TD, Musone SL, Kim JE, Swinton P, Espineda I, Manalac C, deJong PJ, Conklin BR. Marking embryonic stem cells with a 2A self-cleaving peptide: a NKX2-5 emerald GFP BAC reporter. PLoS One 2008; 3:e2532. [PMID: 18596956 PMCID: PMC2430532 DOI: 10.1371/journal.pone.0002532] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 05/23/2008] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Fluorescent reporters are useful for assaying gene expression in living cells and for identifying and isolating pure cell populations from heterogeneous cultures, including embryonic stem (ES) cells. Multiple fluorophores and genetic selection markers exist; however, a system for creating reporter constructs that preserve the regulatory sequences near a gene's native ATG start site has not been widely available. METHODOLOGY Here, we describe a series of modular marker plasmids containing independent reporter, bacterial selection, and eukaryotic selection components, compatible with both Gateway recombination and lambda prophage bacterial artificial chromosome (BAC) recombineering techniques. A 2A self-cleaving peptide links the reporter to the native open reading frame. We use an emerald GFP marker cassette to create a human BAC reporter and ES cell reporter line for the early cardiac marker NKX2-5. NKX2-5 expression was detected in differentiating mouse ES cells and ES cell-derived mice. CONCLUSIONS Our results describe a NKX2-5 ES cell reporter line for studying early events in cardiomyocyte formation. The results also demonstrate that our modular marker plasmids could be used for generating reporters from unmodified BACs, potentially as part of an ES cell reporter library.
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Affiliation(s)
- Edward C Hsiao
- Gladstone Institute of Cardiovascular Disease, San Francisco, California, United States of America.
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20
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Masui S, Ohtsuka S, Yagi R, Takahashi K, Ko MSH, Niwa H. Rex1/Zfp42 is dispensable for pluripotency in mouse ES cells. BMC DEVELOPMENTAL BIOLOGY 2008; 8:45. [PMID: 18433507 PMCID: PMC2386458 DOI: 10.1186/1471-213x-8-45] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2007] [Accepted: 04/24/2008] [Indexed: 12/11/2022]
Abstract
Background Rex1/Zfp42 has been extensively used as a marker for the undifferentiated state of pluripotent stem cells. However, its function in pluripotent stem cells including embryonic stem (ES) cells remained unclear although its involvement in visceral endoderm differentiation in F9 embryonal carcinoma (EC) cells was reported. Results We showed the function of Rex1 in mouse ES cells as well as in embryos using the conventional gene targeting strategy. Our results clearly indicated that Rex1 function is dispensable for both the maintenance of pluripotency in ES cells and the development of embryos. However, Rex1-/- ES cells showed the defect to induce a subset of the marker genes of visceral endoderm, when differentiated as embryoid body, as found in EC cells. Conclusion Rex1 should be regarded just as a marker of pluripotency without functional significance like the activity of alkaline phosphatase.
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Affiliation(s)
- Shinji Masui
- Laboratory for Pluripotent Cell Studies, RIKEN Center for Developmental Biology (CDB), 2-2-3 Minatojima-minamimachi, Kobe, Hyogo 650-0047, Japan.
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21
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Yamanaka S, Li J, Kania G, Elliott S, Wersto RP, Van Eyk J, Wobus AM, Boheler KR. Pluripotency of embryonic stem cells. Cell Tissue Res 2007; 331:5-22. [PMID: 18026755 DOI: 10.1007/s00441-007-0520-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 09/18/2007] [Indexed: 12/27/2022]
Abstract
Embryonic stem (ES) cells derived from pre-implantation embryos have the potential to differentiate into any cell type derived from the three germ layers of ectoderm (epidermal tissues and nerves), mesoderm (muscle, bone, blood), and endoderm (liver, pancreas, gastrointestinal tract, lungs), including fetal and adult cells. Alone, these cells do not develop into a viable fetus or adult animal because they do not retain the potential to contribute to extraembryonic tissue, and in vitro, they lack spatial and temporal signaling cues essential to normal in vivo development. The basis of pluripotentiality resides in conserved regulatory networks composed of numerous transcription factors and multiple signaling cascades. Together, these regulatory networks maintain ES cells in a pluripotent and undifferentiated form; however, alterations in the stoichiometry of these signals promote differentiation. By taking advantage of this differentiation capacity in vitro, ES cells have clearly been shown to possess the potential to generate multipotent stem and progenitor cells capable of differentiating into a limited number of cell fates. These latter types of cells may prove to be therapeutically viable, but perhaps more importantly, the studies of these cells have led to a greater understanding of mammalian development.
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Affiliation(s)
- Satoshi Yamanaka
- Laboratory of Cardiovascular Sciences, Gerontology Research Center, National Institute on Aging, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
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22
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Soprano DR, Teets BW, Soprano KJ. Role of retinoic acid in the differentiation of embryonal carcinoma and embryonic stem cells. VITAMINS AND HORMONES 2007; 75:69-95. [PMID: 17368312 DOI: 10.1016/s0083-6729(06)75003-8] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Retinoic acid (RA), the most potent natural form of vitamin A, plays an important role in many diverse biological processes such as embryogenesis and cellular differentiation. This chapter is a review of the mechanism of action of RA and the role of specific RA-regulated genes during the cellular differentiation of embryonal carcinoma (EC) and embryonic stem (ES) cells. RA acts by binding to its nuclear receptors and inducing transcription of specific target genes. The most studied mouse EC cell lines include F9 cells, which can be induced by RA to differentiate into primitive, parietal, and visceral endodermal cells; and P19 cells, which can differentiate to endodermal and neuronal cells upon RA treatment. ES cells can be induced to differentiate into a number of different cell types; many of which require RA treatment. Over the years, many RA-regulated genes have been discovered in EC and ES cells using a diverse set of techniques. Current research focuses on the elucidation how these genes affect differentiation in EC and ES cells using a variety of molecular biology approaches. However, the exact molecule events that lead from a pluripotent stem cell to a fully differentiated cell following RA treatment are yet to be determined.
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Affiliation(s)
- Dianne Robert Soprano
- Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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23
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Das P, Doyle TJ, Liu D, Kochar J, Kim KH, Rogers MB. Retinoic acid regulation of eye and testis-specific transcripts within a complex locus. Mech Dev 2006; 124:137-45. [PMID: 17166701 PMCID: PMC1847367 DOI: 10.1016/j.mod.2006.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Revised: 10/20/2006] [Accepted: 10/20/2006] [Indexed: 01/01/2023]
Abstract
We previously used a yeast-based enhancer trap to identify a strong, retinoic acid response element (RARE). We have now characterized testis and eye transcripts that are adjacent to this regulatory element. Bioinformatics analysis of expressed sequence tag (EST) clones and RNase protection, reverse transcription-PCR, and Northern blot assays indicate that these two RNAs are transcribed from the same locus on opposite template strands. This positions the RARE upstream of the testis transcript and downstream of the eye transcript. Additionally, these two RNAs are embedded within the third intron of the 329kbp gene that encodes the Zinc Finger and BTB domain containing 7C protein (Zbtb7C). We present evidence indicating that the testis transcript is expressed primarily in spermatocytes and/or early round spermatids. Furthermore, our analyses of transcript levels in eyes and testes isolated from vitamin A deficient mice or from mice with defects in retinoid storage or signaling indicate that retinoids are required for expression in vivo.
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Affiliation(s)
- Pragnya Das
- Department of Biochemistry and Molecular Biology (MSB E627), UMDNJ-New Jersey Medical School, 185 South Orange Avenue, P.O. Box 1709, Newark NJ 07101-1709, USA
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24
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Zhang JZ, Gao W, Yang HB, Zhang B, Zhu ZY, Xue YF. Screening for genes essential for mouse embryonic stem cell self-renewal using a subtractive RNA interference library. Stem Cells 2006; 24:2661-8. [PMID: 16960129 DOI: 10.1634/stemcells.2006-0017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The pluripotency of mouse embryonic stem (ES) cells is maintained by self-renewal. To screen for genes essential for this process, we constructed an RNA interference (RNAi) library by inserting subtracted ES cell cDNA fragments into plasmid containing two opposing cytomegalovirus promoters. ES cells were transfected with individual RNAi plasmids and levels of the pluripotency marker Oct-4 were monitored 48 hours later by real time RT-PCR. Of the first 89 RNAi plasmids characterized, 12 downregulated Oct-4 expression to less than 50% of the normal level and 7 of them upregulated Oct-4 expression to more than 150% of the normal level. To investigate their long-term effect on self-renewal, ES cells were transfected by these 19 RNAi plasmids individually and G418-resistant colonies were subjected to alkaline phosphatase (AP) staining after 7 days selection. Except for 4 plasmids that caused cell death, the ratio of AP positive colonies was repressed to less than 60% of the control group by the other 15 plasmids and even below 20% by 10 plasmids. The cDNA fragments in these 10 plasmids correspond to eight genes, including Zfp42/Rex-1, which was chosen for further functional analysis. RNAi knockdown of Zfp42 induced ES cells differentiate to endoderm and mesoderm lineages, and overexpression of Zfp42 also caused ES cells to lose the capacity of self-renewal. Our results indicate that RNAi screen is a feasible and efficient approach to identify genes involved in ES cells self-renewal. Further functional characterization of these genes will promote our understanding of the complex regulatory networks in ES cells.
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Affiliation(s)
- Jun-Zheng Zhang
- Key Laboratory of Cell Proliferation and Differentiation of Ministry of Education, College of Life Sciences, Peking University, Beijing, China
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25
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Abstract
The Oct-4 gene encodes a transcription factor that is expressed in embryonic stem (ES) cells and germ cells. Oct-4 is known to function as a transcriptional activator of genes involved in maintaining an undifferentiated totipotent state and possibly in preventing expression of genes activated during differentiation. In addition, it is a putative proto-oncogene and a critical player in the genesis of human testicular germ cell tumors. Although much effort has gone toward characterizing Oct-4, there is still little known about the molecular mechanisms and the proteins that regulate Oct-4 function. To identify cofactors that control Oct-4 function in vivo, we used a recently developed bacterial two-hybrid screening system and isolated a novel ES cell-derived cDNA encoding Ewing's sarcoma protein (EWS). EWS is a proto-oncogene and putative RNA-binding protein involved in human cancers. By using glutathione-S-transferase (GST) pull-down assays, we were able to confirm the interaction between Oct-4 and EWS in vitro, and moreover, coimmunoprecipitation and colocalization studies have shown that these proteins also associate in vivo. We have mapped the EWS-interacting region to the POU domain of Oct-4. In addition, three independent sites on EWS are involved in binding to Oct-4. In this study, we report that Oct-4 and EWS are coexpressed in the pluripotent mouse and human ES cells. Consistent with its ability to bind to and colocalize with Oct-4, ectopic expression of EWS enhances the transactivation ability of Oct-4. Moreover, a chimeric protein generated by fusion of EWS (1-295) to the GAL4 DNA-binding domain significantly increases promoter activity of a reporter containing GAL4 DNA-binding sites, suggesting the presence of a strong activation domain within EWS. Taken together, our results suggest that Oct-4-mediated transactivation is stimulated by EWS.
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MESH Headings
- Amino Acid Motifs
- Animals
- Blotting, Northern
- Blotting, Western
- COS Cells
- Cell Line
- Cell Line, Tumor
- Cell Nucleus/metabolism
- DNA, Complementary/metabolism
- DNA-Binding Proteins/biosynthesis
- Embryo, Mammalian/cytology
- Gene Expression Regulation, Neoplastic
- Gene Library
- Genes, Reporter
- Glutathione Transferase/metabolism
- Histidine/chemistry
- Humans
- Immunoprecipitation
- Mice
- NIH 3T3 Cells
- Octamer Transcription Factor-3
- Promoter Regions, Genetic
- Protein Binding
- Protein Biosynthesis
- Protein Structure, Tertiary
- Proto-Oncogene Mas
- RNA/metabolism
- RNA-Binding Protein EWS/metabolism
- RNA-Binding Protein EWS/physiology
- Stem Cells/cytology
- Transcription Factors/biosynthesis
- Transcription, Genetic
- Transcriptional Activation
- Two-Hybrid System Techniques
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Affiliation(s)
- Jungwoon Lee
- Laboratory of Molecular and Cellular Biology, Department of Life Science, Sogang University, Seoul 121-742, Korea
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26
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Wobus AM, Boheler KR. Embryonic stem cells: prospects for developmental biology and cell therapy. Physiol Rev 2005; 85:635-78. [PMID: 15788707 DOI: 10.1152/physrev.00054.2003] [Citation(s) in RCA: 531] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Stem cells represent natural units of embryonic development and tissue regeneration. Embryonic stem (ES) cells, in particular, possess a nearly unlimited self-renewal capacity and developmental potential to differentiate into virtually any cell type of an organism. Mouse ES cells, which are established as permanent cell lines from early embryos, can be regarded as a versatile biological system that has led to major advances in cell and developmental biology. Human ES cell lines, which have recently been derived, may additionally serve as an unlimited source of cells for regenerative medicine. Before therapeutic applications can be realized, important problems must be resolved. Ethical issues surround the derivation of human ES cells from in vitro fertilized blastocysts. Current techniques for directed differentiation into somatic cell populations remain inefficient and yield heterogeneous cell populations. Transplanted ES cell progeny may not function normally in organs, might retain tumorigenic potential, and could be rejected immunologically. The number of human ES cell lines available for research may also be insufficient to adequately determine their therapeutic potential. Recent molecular and cellular advances with mouse ES cells, however, portend the successful use of these cells in therapeutics. This review therefore focuses both on mouse and human ES cells with respect to in vitro propagation and differentiation as well as their use in basic cell and developmental biology and toxicology and presents prospects for human ES cells in tissue regeneration and transplantation.
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Affiliation(s)
- Anna M Wobus
- In Vitro Differentiation Group, IPK Gatersleben, Germany.
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27
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Richards M, Tan SP, Tan JH, Chan WK, Bongso A. The transcriptome profile of human embryonic stem cells as defined by SAGE. Stem Cells 2004; 22:51-64. [PMID: 14688391 DOI: 10.1634/stemcells.22-1-51] [Citation(s) in RCA: 332] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Human embryonic stem (ES) cell lines that have the ability to self-renew and differentiate into specific cell types have been established. The molecular mechanisms for self-renewal and differentiation, however, are poorly understood. We determined the transcriptome profiles for two proprietary human ES cell lines (HES3 and HES4, ES Cell International), and compared them with murine ES cells and other human tissues. Human and mouse ES cells appear to share a number of expressed gene products although there are numerous notable differences, including an inactive leukemia inhibitory factor pathway and the high preponderance of several important genes like POU5F1 and SOX2 in human ES cells. We have established a list of genes comprised of known ES-specific genes and new candidates that can serve as markers for human ES cells and may also contribute to the "stemness" phenotype. Of particular interest was the downregulation of DNMT3B and LIN28 mRNAs during ES cell differentiation. The overlapping similarities and differences in gene expression profiles of human and mouse ES cells provide a foundation for a detailed and concerted dissection of the molecular and cellular mechanisms governing their pluripotency, directed differentiation into specific cell types, and extended ability for self-renewal.
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Affiliation(s)
- Mark Richards
- Department of Obstetrics and Gynecology, National University of Singapore, National University Hospital, Singapore
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28
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Thompson JR, Gudas LJ. Retinoic acid induces parietal endoderm but not primitive endoderm and visceral endoderm differentiation in F9 teratocarcinoma stem cells with a targeted deletion of the Rex-1 (Zfp-42) gene. Mol Cell Endocrinol 2002; 195:119-33. [PMID: 12354678 DOI: 10.1016/s0303-7207(02)00180-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cultured murine F9 teratocarcinoma stem cells resemble pluripotent stem cells of the inner cell mass of the mouse blastocyst and, depending upon their treatment, can be induced to differentiate along the primitive endoderm, the parietal endoderm (PE), or the visceral endoderm (VE) pathway. The Rex-1 gene encodes a zinc finger family transcription factor which is expressed at high levels in undifferentiated F9 stem cells, embryonic stem cells, and in other types of stem cells. To examine whether the Rex-1 protein plays a role in F9 cell differentiation, homologous recombination was employed to generate F9 cell lines which lack both alleles of Rex-1. F9 wild type cells in monolayer culture require both retinoic acid and cyclic AMP analogs to differentiate into PE, whereas the F9 Rex-1(-/-) cells differentiate into PE, as assessed by several molecular markers, including thrombomodulin and laminin B1, in the presence of RA alone. The F9 Rex-1(-/-) cells do not completely differentiate into VE after RA treatment in aggregate culture; they do not express alpha-fetoprotein, a definitive marker of VE differentiation. These results indicate that the Rex-1 transcription factor regulates the differentiation of F9 stem cells along several distinct cell lineages found in the early embryo.
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Affiliation(s)
- James R Thompson
- Department of Pharmacology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
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29
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Abstract
Embryonic stem (ES) cells are pluripotent stem cells that differentiate both in vitro and in vivo into cell types derived from each of the three embryonic germ layers. ES cells and their close relatives, embryonal carcinoma (EC) cells and embryonic germ (EG) cells, have been used extensively as model systems for studying early mammalian development. This work has led to important insights into the mechanisms that control embryogenesis at the molecular and cellular levels. This chapter focuses on the use of ES cells as an in vitro model system for studying cellular differentiation and reviews several areas where important progress has been made. Impressive progress has been made in the isolation and characterization of ES cells from many species, including humans. Significant progress has also been made in the development of culture conditions that help direct the differentiation of ES cells to specific cell types that form during myogenesis, angiogenesis, hematopoiesis, neurogenesis, and cardiogenesis. The ability to inactivate virtually any gene in ES cells by gene targeting has vastly improved our understanding of the roles played by specific genes at the cellular and organismic levels. Moreover, ES cells and EC cells have been used widely to investigate how specific genes are turned on and turned off in the course of differentiation. In this connection, DNA array technology has been used to identify genes regulated when ES cells differentiate. The final section of this chapter discusses how work with ES cells is shaping our understanding of stem cells, mammalian development, and cell replacement therapy.
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Affiliation(s)
- Angie Rizzino
- Eppley Institute for Cancer Research and Allied Diseases, University of Nebraska Medical Center, 986805 Nebraska Medical Center, Omaha, Nebraska 68198-6805, USA
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Eiges R, Schuldiner M, Drukker M, Yanuka O, Itskovitz-Eldor J, Benvenisty N. Establishment of human embryonic stem cell-transfected clones carrying a marker for undifferentiated cells. Curr Biol 2001; 11:514-8. [PMID: 11413002 DOI: 10.1016/s0960-9822(01)00144-0] [Citation(s) in RCA: 275] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Human embryonic stem (ES) cells are pluripotent cell lines that have been derived from the inner cell mass (ICM) of blastocyst stage embryos [1--3]. They are characterized by their ability to be propagated indefinitely in culture as undifferentiated cells with a normal karyotype and can be induced to differentiate in vitro into various cell types [1, 2, 4-- 6]. Thus, human ES cells promise to serve as an unlimited cell source for transplantation. However, these unique cell lines tend to spontaneously differentiate in culture and therefore are difficult to maintain. Furthermore, colonies may contain several cell types and may be composed of cells other than pluripotent cells [1, 2, 6]. In order to overcome these difficulties and establish lines of cells with an undifferentiated phenotype, we have introduced a reporter gene that is regulated by a promoter of an ES cell-enriched gene into the cells. For the introduction of DNA into human ES cells, we have established a specific transfection protocol that is different from the one used for murine ES cells. Human ES cells were transfected with enhanced green fluorescence protein (EGFP), under the control of murine Rex1 promoter. The transfected cells show high levels of GFP expression when in an undifferentiated state. As the cells differentiate, this expression is dramatically reduced in monolayer cultures as well as in the primitive endoderm of early stage (simple) embryoid bodies (EBs) and in mature EBs. The undifferentiated cells expressing GFP can be analyzed and sorted by using a Fluorescence Activated Cell Sorter (FACS). Thus, we have established lines of human ES cells in which only undifferentiated cells are fluorescent, and these cells can be followed and selected for in culture. We also propose that the pluripotent nature of the culture is made evident by the ability of the homogeneous cell population to form EBs. The ability to efficiently transfect human ES cells will provide the means to study and manipulate these cells for the purpose of basic and applied research.
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Affiliation(s)
- R Eiges
- Department of Genetics, The Institute of Life Sciences, The Hebrew University, Jerusalem 91904, Israel
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The Regulation and Reprogramming of Gene Expression in the Preimplantation Embryo. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1064-2722(08)60019-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Faria TN, LaRosa GJ, Wilen E, Liao J, Gudas LJ. Characterization of genes which exhibit reduced expression during the retinoic acid-induced differentiation of F9 teratocarcinoma cells: involvement of cyclin D3 in RA-mediated growth arrest. Mol Cell Endocrinol 1998; 143:155-66. [PMID: 9806360 DOI: 10.1016/s0303-7207(98)00127-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In the presence of retinoic acid (RA), F9 murine teratocarcinoma cells differentiate into cells resembling the extra-embryonic endoderm of the early mouse embryo. Using differential hybridization, we have cloned and characterized six cDNAs corresponding to mRNAs that exhibit reduced expression in F9 cells following RA treatment. Two of these cDNAs encode novel genes (REX-2 and REX-3). The other isolated cDNAs encode genes that have been previously described in other contexts: 1-4 (cyclin D3); 2-10 (pyruvate kinase); 2-12 (glutathione S-transferase); and 2-17 (GLUT 3). The mRNA levels of these genes are reduced by RA or RA plus theophylline and cAMP (RACT) only after 48 h of treatment, and continue to decrease at 96 h. The half-lives of these mRNAs are not changed by RA treatment, indicating that these mRNAs may be regulated through a transcriptional mechanism. In isoleucine-deprived cells, which are growth arrested but do not differentiate, the steady state mRNA levels of genes Rex 2, Rex 3, pyruvate kinase and GLUT 3 are not reduced, in contrast to cyclin D3 and glutathione S-transferase. The expression of the REX-2, REX-3, pyruvate kinase, glutathione S-transferase and GLUT 3 genes is reduced by RACT to the same extent in F9 RARgamma-/- and RARalpha-/- lines as in F9-Wt. In contrast, cyclin D3 exhibits lower mRNA expression in F9 RARgamma-/- and RARalpha-/- stem cells, and this mRNA is not decreased by RACT treatment. Overexpression of cyclin D3 blocks the RA-induced growth arrest of F9 cells, indicating that the downregulation of this gene following RA treatment may constitute a necessary step in the cascade of events leading to growth inhibition by RA.
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Affiliation(s)
- T N Faria
- Department of Pharmacology, Cornell University Medical College, New York, NY 10021, USA
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Abstract
This review focuses on known genes whose expression may be perturbed by teratogens during early embryogenesis (preorganogenesis). Teratogens may disrupt embryogenesis by modifying positional information. Genes controlling positional information include those specifying the primary body axes: anterior-posterior, dorsal-ventral, or left-right. These genes often encode transcription factors, whose regulation or activation can stimulate aberrant tissue differentiation and morphogenesis. Alternatively, teratogens may directly affect cell differentiation, proliferation, or apoptosis. Hydrophilic signalling molecules such as growth factors and hydrophobic molecules such as retinoids regulate these processes. The signalling pathways activated often induce the coordinate regulation of tissue specific gene expression. In addition to modifying individual signalling pathways, teratogens can synergize with or antagonize the effects of other teratogens through inappropriate interactions between signal transduction pathways. Since teratogens may often directly or indirectly perturb the expression of known or as yet undescribed developmentally critical genes, this review also provides a short description of techniques to identify genes whose expression is altered by teratogens.
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Affiliation(s)
- M B Rogers
- Department of Biology, University of South Florida, Tampa 33620-5150, USA.
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Favor J, Grimes P, Neuhäuser-Klaus A, Pretsch W, Stambolian D. The mouse Cat4 locus maps to chromosome 8 and mutants express lens-corneal adhesion. Mamm Genome 1997; 8:403-6. [PMID: 9166583 DOI: 10.1007/s003359900456] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cat4 is the second largest allelism group in the collection of mouse dominant eye mutations recovered in Neuherberg and carriers express anterior polar cataract, central corneal opacity, and lens-corneal adhesions. We have mapped the Cat4 locus of the mouse to central Chromosome (Chr) 8 at position cM 31. Histological characterization of Cat4(a) heterozygotes and homozygotes indicates failure of separation of the lens vesicle from the surface ectoderm. Human anterior segment ocular dysgenesis (ASOD) is autosomal dominant, carriers express an eye phenotype similar to that of Cat4(a) carriers, and it has been mapped to a region of 4q homologous to mouse central Chr 8. Thus, on the basis of phenotype and map position, Cat4 may be a mouse model of human ASOD. The genes Junb, Jund1, Mel, and Zfp42 are discussed as possible candidates for Cat4.
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Affiliation(s)
- J Favor
- Institute of Mammalian Genetics, GSF-National Research Center for Environment and Health, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany
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Lyu MS, Park DJ, Rhee SG, Kozak CA. Genetic mapping of the human and mouse phospholipase C genes. Mamm Genome 1996; 7:501-4. [PMID: 8672127 DOI: 10.1007/s003359900151] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To determine chromosome positions for 10 mouse phospholipase C (PLC) genes, we typed the progeny of two sets of genetic crosses for inheritance of restriction enzyme polymorphisms of each PLC. Four mouse chromosomes, Chr 1, 11, 12, and 19, contained single PLC genes. Four PLC loci, Plcb1, Plcb2, Plcb4, and Plcg1, mapped to three sites on distal mouse Chr 2. Two PLC genes, Plcd1 and Plcg2, mapped to distinct sites on Chr 8. We mapped the human homologs of eight of these genes to six chromosomes by analysis of human x rodent somatic cell hybrids. The map locations of seven of these genes were consistent with previously defined regions of conserved synteny; Plcd1 defines a new region of homology between human Chr 3 and mouse Chr 8.
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Affiliation(s)
- M S Lyu
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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Marine JC, Gilbert DJ, Bellefroid EJ, Martial JA, Ihle JN, Copeland NG, Jenkins NA. Chromosomal location of fifteen unique mouse KRAB-containing zinc finger loci. Mamm Genome 1996; 7:413-6. [PMID: 8662221 DOI: 10.1007/s003359900123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The mammalian genome contains hundreds if not thousands of zinc finger protein (Zfp) genes. While the function of most of these genes remains to be determined, it is clear that a few of them play important roles in gene regulation and development. In studies described here, we have used an interspecific mouse backcross mapping panel to determine the chromosomal location of 15 KRAB-containing zinc finger loci. These loci map to nine different mouse autosomes and the X Chromosome (Chr). Two Chrs, 7 and 9, contain cosegregating pairs of KRAB-containing Zfp genes, indicating that the KRAB-containing Zfp genes have evolved through processes involving regional as well as genome-wide duplication events.
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Affiliation(s)
- J C Marine
- Laboratoire de Biologie Moléculaire et de Génie Génétique, Université de Liège, Belgium
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Kraft HJ, Mosselman S, Smits HA, Hohenstein P, Piek E, Chen Q, Artzt K, van Zoelen EJ. Oct-4 regulates alternative platelet-derived growth factor alpha receptor gene promoter in human embryonal carcinoma cells. J Biol Chem 1996; 271:12873-8. [PMID: 8662786 DOI: 10.1074/jbc.271.22.12873] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Expression of the platelet-derived growth factor alpha-receptor (PDGFalphaR) gene is tightly controlled in mammalian embryogenesis. A well established model system to study human embryogenesis is the embryonal carcinoma cell line Tera2. We have shown previously that retinoic acid-differentiated Tera2 cells express two PDGFalphaR transcripts of 6.4 kilobase pairs (kb) (encoding the full-length receptor) and 3.0 kb, respectively, whereas in contrast, undifferentiated Tera2 cells express PDFGalphaR transcripts of 1.5 kb and 5.0 kb. Here we show that this switch in PDGFalphaR expression pattern during differentiation of Tera2 cells results from alternative promoter use. In undifferentiated cells, a second promoter is used, which is located in intron 12 of the PDGFalphaR gene. Functional analysis shows that this promoter contains a consensus octamer motif, which can be bound by the POU domain transcription factor Oct-4. Oct-4 is expressed in undifferentiated Tera2 cells but not in retinoic acid-induced differentiated cells. Mutation of the octamer motif decreases promoter activity, while ectopic expression of Oct-4 in differentiated Tera2 cells specifically enhances the activity of this PDGFalphaR promoter. Therefore, we suggest that an important aspect in the maintenance of the undifferentiated state of human embryonal carcinoma cells results from Oct-4 expression, which thereupon activates this PDGFalphaR promoter.
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Affiliation(s)
- H J Kraft
- Department of Cell Biology, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, The Netherlands
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Schoorlemmer J, Jonk L, Sanbing S, van Puijenbroek A, Feijen A, Kruijer W. Regulation of Oct-4 gene expression during differentiation of EC cells. Mol Biol Rep 1995; 21:129-40. [PMID: 8832901 DOI: 10.1007/bf00997235] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
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, no RA-induced down regulation of Oct-4 expression is observed in the P19-derived RA-resistant RAC65 cells. However, in these cells Oct-4 promoter repression can be rescued in a RA-dependent manner by cotransfection of RAR alpha 2 or RAR beta 2 but not RARr gamma 1, matching previously reported transactivation properties of these receptor types. In the vicinity of the transcription initiation site of the Oct-4 gene, three Hormone Response Element HRE half sites are present which are arranged as direct repeats with different spacing. In vitro translated RAR and RXR proteins bind to this HRE as heterodimers with low affinity, in such a way that all three HRE half sites contribute to complex formation. Although P19 EC cells contain weak binding activity interacting with the Oct-4 promoter HRE, strong binding activity is observed in nuclear extracts from RA-treated P19 cells. This binding activity was shown to correspond to COUP-TFs but not nuclear RA receptors. Moreover, the presence of these binding factors in nuclear extracts corresponds to silencing of Oct-4 expression. These results implicate RA and the action of its nuclear receptors in silencing Oct-4 expression upon differentiation of EC cells. The observed silencing is most likely not exerted by direct binding of RARs to the Oct-4 proximal promoter HRE. Our results support models in which different nuclear receptor complexes sequentially occupy different sites in the Oct-4 promoter HRE to silence Oct-4 expression during RA-induced differentiation.
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Affiliation(s)
- J Schoorlemmer
- Hubrecht Laboratorium, Netherlands Institute for Developmental Biology, The Netherlands
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