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Liu S, Lian Y, Song Y, Chen Q, Huang J. De Novo Assembly, Characterization and Comparative Transcriptome Analysis of the Gonads of Jade Perch ( Scortum barcoo). Animals (Basel) 2023; 13:2254. [PMID: 37508032 PMCID: PMC10376888 DOI: 10.3390/ani13142254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/24/2023] [Accepted: 07/03/2023] [Indexed: 07/30/2023] Open
Abstract
Due to the high meat yield and rich nutritional content, jade perch (Scortum barcoo) has become an important commercial aquaculture species in China. Jade perch has a slow growth rate, taking 3-4 years to reach sexual maturity, and has almost no difference in body size between males and females. However, the study of its gonad development and reproduction regulation is still blank, which limited the yield increase. Herein, the gonad transcriptomes of juvenile males and females of S. barcoo were identified for the first time. A total of 107,060 unigenes were successfully annotated. By comparing male and female gonad transcriptomes, a total of 23,849 differentially expressed genes (DEGs) were identified, of which 9517 were downregulated, and 14,332 were upregulated in the testis. In addition, a large number of DEGs involved in sex differentiation, gonadal development and differentiation and gametogenesis were identified, and the differential expression patterns of some genes were further verified using real-time fluorescence quantitative PCR. The results of this study will provide a valuable resource for further studies on sex determination and gonadal development of S. barcoo.
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Affiliation(s)
- Shiyan Liu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yingying Lian
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yikun Song
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Qinghua Chen
- South China Institute of Environmental Science, MEE, Guangzhou 510610, China
| | - Jianrong Huang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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2
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Kim JH, Choi MH. Embryonic Development and Adult Regeneration of the Adrenal Gland. Endocrinol Metab (Seoul) 2020; 35:765-773. [PMID: 33397037 PMCID: PMC7803617 DOI: 10.3803/enm.2020.403] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
The adrenal gland plays a pivotal role in an organism's health span by controlling the endocrine system. Decades of research on the adrenal gland have provided multiscale insights into the development and maintenance of this essential organ. A particularly interesting finding is that founder stem/progenitor cells participate in adrenocortical development and enable the adult adrenal cortex to regenerate itself in response to hormonal stress and injury. Since major advances have been made in understanding the dynamics of the developmental process and the remarkable regenerative capacity of the adrenal gland, understanding the mechanisms underlying adrenal development, maintenance, and regeneration will be of interest to basic and clinical researchers. Here, we introduce the developmental processes of the adrenal gland and discuss current knowledge regarding stem/progenitor cells that regulate adrenal cortex remodeling and regeneration. This review will provide insights into the fascinating ongoing research on the development and regeneration of the adrenal cortex.
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Affiliation(s)
- Ji-Hoon Kim
- School of Biological Sciences, Seoul National University, Seoul,
Korea
| | - Man Ho Choi
- Molecular Recognition Research Center, Korea Institute of Science and Technology, Seoul,
Korea
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3
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Whitworth DJ, Limnios IJ, Gauthier ME, Weeratunga P, Ovchinnikov DA, Baillie G, Grimmond SM, Graves JAM, Wolvetang EJ. Platypus Induced Pluripotent Stem Cells: The Unique Pluripotency Signature of a Monotreme. Stem Cells Dev 2019; 28:151-164. [PMID: 30417748 DOI: 10.1089/scd.2018.0179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The platypus (Ornithorhynchus anatinus) is an egg-laying monotreme mammal whose ancestors diverged ∼166 million years ago from the evolutionary pathway that eventually gave rise to both marsupial and eutherian mammals. Consequently, its genome is an extraordinary amalgam of both ancestral reptilian and derived mammalian features. To gain insight into the evolution of mammalian pluripotency, we have generated induced pluripotent stem cells from the platypus (piPSCs). Deep sequencing of the piPSC transcriptome revealed that piPSCs robustly express the core eutherian pluripotency factors POU5F1/OCT4, SOX2, and NANOG. Given the more extensive role of SOX3 over SOX2 in avian pluripotency, our data indicate that between 315 and 166 million years ago, primitive mammals replaced the role of SOX3 in the vertebrate pluripotency network with SOX2. DAX1/NR0B1 is not expressed in piPSCs and an analysis of the platypus DAX1 promoter revealed the absence of a proximal SOX2-binding DNA motif known to be critical for DAX1 expression in eutherian pluripotent stem cells, suggesting that the acquisition of SOX2 responsiveness by DAX1 has facilitated its recruitment into the pluripotency network of eutherians. Using the RNAseq data, we were also able to demonstrate that in both fibroblasts and piPSCs, the expression ratio of X chromosomes to autosomes (X1-5 X1-5:AA) is approximately equal to 1, indicating that there is no upregulation of X-linked genes. Finally, the RNAseq data also allowed us to explore the process of X-linked gene inactivation in the platypus, where we determined that for any given gene, there is no preference for silencing of the maternal or paternal allele; that is, within a population of cells, the silencing of X-linked genes is not imprinted.
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Affiliation(s)
- Deanne J Whitworth
- 1 School of Veterinary Science, University of Queensland, Gatton, Australia.,2 Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Australia
| | - Ioannis J Limnios
- 2 Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Australia.,3 Research School of Biology, Australian National University, Acton, Australia.,4 Clem Jones Centre for Regenerative Medicine, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia
| | | | | | - Dmitry A Ovchinnikov
- 2 Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Australia
| | - Gregory Baillie
- 5 Institute for Molecular Bioscience, University of Queensland, St Lucia, Australia
| | - Sean M Grimmond
- 5 Institute for Molecular Bioscience, University of Queensland, St Lucia, Australia
| | | | - Ernst J Wolvetang
- 2 Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Australia
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4
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Temporal expression of pluripotency-associated transcription factors in sheep and cattle preimplantation embryos. ZYGOTE 2018; 26:270-278. [PMID: 30033902 DOI: 10.1017/s0967199418000175] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SummaryPluripotency-associated transcription factors (PATFs) modulate gene expression during early mammalian embryogenesis. Despite a strong understanding of PATFs during mouse embryogenesis, limited progress has been made in ruminants. This work aimed to describe the temporal expression of eight PATFs during both sheep and cattle preimplantation development. Transcript availability of PATFs was evaluated by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in eggs, cleavage-stage embryos, morulae, and blastocysts. Transcripts of five genes were detected in all developmental stages of both species (KLF5, OCT4, RONIN, ZFP281, and ZFX). Furthermore, CMYC was detected in all cattle samples but was found from cleavage-stage onwards in sheep. In contrast, NR0B1 was detected in all sheep samples but was not detected in cattle morulae. GLIS1 displayed the most significant variation in temporal expression between species, as this PATF was only detected in cattle eggs and sheep cleavage-stage embryos and blastocysts. In silico analysis suggested that cattle and sheep PATFs share similar size, isometric point and molecular weight. A phenetic analysis showed two patterns of PATF clustering between cattle and sheep, among several mammalian species. In conclusion, the temporal expression of pluripotency-associated transcription factors differs between sheep and cattle, suggesting species-specific regulation during preimplantation development.
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Abstract
Pluripotent cells in embryos are situated near the apex of the hierarchy of developmental potential. They are capable of generating all cell types of the mammalian body proper. Therefore, they are the exemplar of stem cells. In vivo, pluripotent cells exist transiently and become expended within a few days of their establishment. Yet, when explanted into artificial culture conditions, they can be indefinitely propagated in vitro as pluripotent stem cell lines. A host of transcription factors and regulatory genes are now known to underpin the pluripotent state. Nonetheless, how pluripotent cells are equipped with their vast multilineage differentiation potential remains elusive. Consensus holds that pluripotency transcription factors prevent differentiation by inhibiting the expression of differentiation genes. However, this does not explain the developmental potential of pluripotent cells. We have presented another emergent perspective, namely, that pluripotency factors function as lineage specifiers that enable pluripotent cells to differentiate into specific lineages, therefore endowing pluripotent cells with their multilineage potential. Here we provide a comprehensive overview of the developmental biology, transcription factors, and extrinsic signaling associated with pluripotent cells, and their accompanying subtypes, in vitro heterogeneity and chromatin states. Although much has been learned since the appreciation of mammalian pluripotency in the 1950s and the derivation of embryonic stem cell lines in 1981, we will specifically emphasize what currently remains unclear. However, the view that pluripotency factors capacitate differentiation, recently corroborated by experimental evidence, might perhaps address the long-standing question of how pluripotent cells are endowed with their multilineage differentiation potential.
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Affiliation(s)
- Kyle M. Loh
- Department of Developmental Biology and the Stanford Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Stanford, California; Genome Institute of Singapore, Stem Cell & Regenerative Biology Group, Agency for Science, Technology & Research, Singapore; and Department of Medicine and the Beth Israel Deaconess Medical Center, Division of Hematology/Oncology, Harvard Medical School, Boston, Massachusetts
| | - Bing Lim
- Department of Developmental Biology and the Stanford Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Stanford, California; Genome Institute of Singapore, Stem Cell & Regenerative Biology Group, Agency for Science, Technology & Research, Singapore; and Department of Medicine and the Beth Israel Deaconess Medical Center, Division of Hematology/Oncology, Harvard Medical School, Boston, Massachusetts
| | - Lay Teng Ang
- Department of Developmental Biology and the Stanford Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine, Stanford, California; Genome Institute of Singapore, Stem Cell & Regenerative Biology Group, Agency for Science, Technology & Research, Singapore; and Department of Medicine and the Beth Israel Deaconess Medical Center, Division of Hematology/Oncology, Harvard Medical School, Boston, Massachusetts
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6
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Zhang J, Liu G, Ruan Y, Wang J, Zhao K, Wan Y, Liu B, Zheng H, Peng T, Wu W, He P, Hu FQ, Jian R. Dax1 and Nanog act in parallel to stabilize mouse embryonic stem cells and induced pluripotency. Nat Commun 2014; 5:5042. [PMID: 25284313 PMCID: PMC4205889 DOI: 10.1038/ncomms6042] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 08/20/2014] [Indexed: 12/20/2022] Open
Abstract
Nanog expression is heterogeneous and dynamic in embryonic stem cells (ESCs). However, the mechanism for stabilizing pluripotency during the transitions between Nanog(high) and Nanog(low) states is not well understood. Here we report that Dax1 acts in parallel with Nanog to regulate mouse ESC (mESCs) identity. Dax1 stable knockdown mESCs are predisposed towards differentiation but do not lose pluripotency, whereas Dax1 overexpression supports LIF-independent self-renewal. Although partially complementary, Dax1 and Nanog function independently and cannot replace one another. They are both required for full reprogramming to induce pluripotency. Importantly, Dax1 is indispensable for self-renewal of Nanog(low) mESCs. Moreover, we report that Dax1 prevents extra-embryonic endoderm (ExEn) commitment by directly repressing Gata6 transcription. Dax1 may also mediate inhibition of trophectoderm differentiation independent or as a downstream effector of Oct4. These findings establish a basal role of Dax1 in maintaining pluripotency during the state transition of mESCs and somatic cell reprogramming.
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Affiliation(s)
- Junlei Zhang
- Department of Microbiology, Third Military Medical University, Chongqing 400038, China
| | - Gaoke Liu
- Department of Microbiology, Third Military Medical University, Chongqing 400038, China
| | - Yan Ruan
- Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, China
| | - Jiali Wang
- Department of Physiology, Third Military Medical University, Chongqing 400038, China
| | - Ke Zhao
- Laboratory of Oncology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing 400038, China
| | - Ying Wan
- 1] Biomedical Analysis Center, Third Military Medical University, Chongqing 100071, China [2] Department of Immunology, Third Military Medical University, Chongqing 400038, China
| | - Bing Liu
- Laboratory of Oncology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing 400038, China
| | - Hongting Zheng
- Department of Endocrinology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Tao Peng
- Research Center of Laboratory Medicine, Chengdu Military General Hospital, Sichuan 610083, China
| | - Wei Wu
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Ping He
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Fu-Quan Hu
- Department of Microbiology, Third Military Medical University, Chongqing 400038, China
| | - Rui Jian
- Department of Pathogenic Biology, Third Military Medical University, Chongqing 400038, China
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7
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von Schalburg KR, Gowen BE, Messmer AM, Davidson WS, Koop BF. Sex-specific expression and localization of aromatase and its regulators during embryonic and larval development of Atlantic salmon. Comp Biochem Physiol B Biochem Mol Biol 2014; 168:33-44. [DOI: 10.1016/j.cbpb.2013.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/03/2013] [Accepted: 11/06/2013] [Indexed: 01/05/2023]
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8
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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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9
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Wagner RT, Cooney AJ. Minireview: the diverse roles of nuclear receptors in the regulation of embryonic stem cell pluripotency. Mol Endocrinol 2013; 27:864-78. [PMID: 23504955 PMCID: PMC3656235 DOI: 10.1210/me.2012-1383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 02/01/2013] [Indexed: 11/19/2022] Open
Abstract
Extensive research has been devoted to the goal of understanding how a single cell of embryonic origin can give rise to every somatic cell type and the germ cell lineage, a hallmark defined as "pluripotency." The aggregate of this work supports fundamentally important roles for the gene transcription networks inherent to the pluripotent cell. Transcription networks have been identified that are both required for pluripotency, as well as sufficient to reprogram somatic cells to a naive pluripotent state. Several members of the nuclear receptor (NR) superfamily of transcription factors have been identified to play diverse roles in the regulation of pluripotency. The ligand-responsive nature of NRs coupled with the abundance of genetic models available has led to a significant advance in the understanding of NR roles in embryonic stem cell pluripotency. Furthermore, the presence of a ligand-binding domain may lead to development of small molecules for a wide range of therapeutic and research applications, even in cases of NRs that are not known to respond to physiologic ligands. Presented here is an overview of NR regulation of pluripotency with a focus on the transcriptional, proteomic, and epigenetic mechanisms by which they promote or suppress the pluripotent state.
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Affiliation(s)
- Ryan T Wagner
- Department of Cell Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston TX 77030-3498, USA
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10
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Li M, Wu F, Gu Y, Wang T, Wang H, Yang S, Sun Y, Zhou L, Huang X, Jiao B, Cheng CHK, Wang D. Insulin-like growth factor 3 regulates expression of genes encoding steroidogenic enzymes and key transcription factors in the Nile tilapia gonad. Biol Reprod 2012; 86:163, 1-10. [PMID: 22337331 DOI: 10.1095/biolreprod.111.096248] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Insulin-like growth factors (Igfs) are implicated in a wide variety of physiological roles in teleost gonadal development and reproduction. In the present study, igf3 mRNA expression in the tilapia ovary was found to be higher than in the testis from 5 to 40 days after hatching (dah) but was lower than that in testis from 50 to 70 dah. Consistently, Igf3 protein signal was detected in the somatic cells of XX and XY gonads from 10 dah until adulthood by immunohistochemistry, using a specific Igf3 polyclonal antibody. Incubation of ovarian and testicular cells in primary culture with recombinant Igf3 significantly increased nr5a1, foxl2, dmrt1, cyp19a1a, cyp11a1, cyp11b2, hsd3b2 , and cyp17a1 expression in a time- and dose-dependent manner. Promoter analysis using luciferase assays in HEK293 cells revealed that igf3 promoter activity was directly activated by Nr5a1 (Sf1) and further enhanced by Foxl2, Nr0b1a (Dax1), and Nr0b1b (Dax2) but repressed by Dmrt1 and estrogen receptor (Esr1, Esr2a, or Esr2b) along with 17beta-estradiol treatment. In addition, igf3 promoter activity was increased slightly by forskolin treatment alone but synergistically up-regulated by transfection with nr5a1. These in vitro results correlated well with the expression profile of igf3 during early gonad differentiation. Our results indicated that igf3 is involved in fish gonad steroidogenesis because of its ability to regulate the expression of foxl2, dmrt1, and nr5a1 and steroidogenic enzymes. The expression of igf3 is in turn regulated by transcription factors Foxl2, Dmrt1, and Nr5a1, as well as by 17beta-estradiol treatment.
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Affiliation(s)
- Minghui Li
- Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, School of Life Science, Southwest University, Chongqing, China
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11
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Teets BW, Soprano KJ, Soprano DR. Role of SF-1 and DAX-1 during differentiation of P19 cells by retinoic acid. J Cell Physiol 2012; 227:1501-11. [PMID: 21678401 DOI: 10.1002/jcp.22866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Retinoic acid (RA) is critical for embryonic development and cellular differentiation. Previous work in our laboratory has shown that blocking the RA-dependent increase in pre-β cell leukemia transcription factors (PBX) mRNA and protein levels in P19 cells prevents endodermal and neuronal differentiation. Dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1) and steroidogenic factor (SF-1) were found by microarray analysis to be regulated by PBX in P19 cells. To determine the roles of DAX-1 and SF-1 during RA-dependent differentiation, P19 cells that inducibly express either FLAG-DAX-1 or FLAG-SF-1 were prepared. Unexpectedly, overexpression of DAX-1 had no effect on the RA-induced differentiation of P19 cells to either endodermal or neuronal cells. However, SF-1 overexpression prevented the RA-dependent loss of OCT-4, DAX-1 and the increase in COUP-TFI, COUP-TFII, and ETS-1 mRNA levels during the commitment stages of both endodermal and neuronal differentiation. Surprisingly, continued expression of SF-1 for 7 days caused the RA-independent loss of OCT-4 protein and RA-dependent loss of SSEA-1 expression. Despite the loss of well-characterized pluripotency markers, these cells did not terminally differentiate into either endodermal or neuronal cells. Instead, the cells gained the expression of many steroidogenic enzymes with a pattern consistent with adrenal cells. Finally, we found evidence for a feedback loop in which PBX reduces SF-1 mRNA levels while continued SF-1 expression blocks the RA-dependent increase in PBX levels. Taken together, these data demonstrate that SF-1 plays a dynamic role during the differentiation of P19 cells and potentially during early embryogenesis.
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Affiliation(s)
- Bryan W Teets
- Department of Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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12
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Jadhav U, Harris RM, Jameson JL. Hypogonadotropic hypogonadism in subjects with DAX1 mutations. Mol Cell Endocrinol 2011; 346:65-73. [PMID: 21672607 PMCID: PMC3185185 DOI: 10.1016/j.mce.2011.04.017] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/07/2011] [Indexed: 11/17/2022]
Abstract
DAX1 (dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1; also known as NROB1, nuclear receptor subfamily 0, group B, member 1) encodes a nuclear receptor that is expressed in embryonic stem (ES) cells, steroidogenic tissues (gonads, adrenals), the ventromedial hypothalamus (VMH), and pituitary gonadotropes. Humans with DAX1 mutations develop an X-linked syndrome referred to as adrenal hypoplasia congenita (AHC). These boys typically present in infancy with adrenal failure but later fail to undergo puberty because of hypogonadotropic hypogonadism (HHG). The adrenal failure reflects a developmental abnormality in the transition of the fetal to adult zone, resulting in glucocorticoid and mineralocorticoid deficiency. The etiology of HHG involves a combined and variable deficiency of hypothalamic GnRH secretion and/or pituitary responsiveness to GnRH resulting in low LH, FSH and testosterone. Treatment with exogenous gonadotropins generally does not induce spermatogenesis. Animal models indicate that DAX1 also plays a critical role in testis development and function. As a nuclear receptor, DAX1 has been shown to function as a transcriptional repressor, particularly of pathways regulated by other nuclear receptors, such as steroidogenic factor 1 (SF1). In addition to reproductive tissues, DAX1 is also expressed at high levels in ES cells and plays a role in the maintenance of pluripotentiality. Here we review the clinical manifestations associated with DAX1 mutations as well as the evolving information about its function based on animal models and in vitro studies.
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Affiliation(s)
| | | | - J. Larry Jameson
- Corresponding author: J. Larry Jameson, MD, PhD, Vice-President for Medical Affairs and Lewis Landsberg Dean, Northwestern University Feinberg School of Medicine, Arthur J. Rubloff Building, 420 East Superior St., 12th floor, Chicago, IL 60611, , Ph: 312-503-0340; Fax: 312-503-7757
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13
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Mazilu JK, McCabe ERB. Moving toward personalized cell-based interventions for adrenal cortical disorders: part 1--Adrenal development and function, and roles of transcription factors and signaling proteins. Mol Genet Metab 2011; 104:72-9. [PMID: 21764344 DOI: 10.1016/j.ymgme.2011.06.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 06/16/2011] [Accepted: 06/16/2011] [Indexed: 11/19/2022]
Abstract
Transdifferentiation of an individual's own cells into functional differentiated cells to replace an organ's lost function would be a personalized approach to therapeutics. In this two part series, we will describe the progress toward establishing functional transdifferentiated adrenal cortical cells. In this article (Part 1), we describe adrenal development and function, and discuss genes involved in these processess and selected for use in our pilot studies of transdifferentiation that are presented in the second article (Part 2).
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Affiliation(s)
- Jaime K Mazilu
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California Los Angeles, Los Angeles, CA 90095, USA
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14
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Nuclear Receptors in Regulation of Mouse ES Cell Pluripotency and Differentiation. PPAR Res 2011; 2007:61563. [PMID: 18274628 PMCID: PMC2233893 DOI: 10.1155/2007/61563] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 06/11/2007] [Indexed: 12/25/2022] Open
Abstract
Embryonic stem (ES) cells have great therapeutic potential because they are capable of indefinite self-renewal and have the potential to differentiate into over 200 different cell types that compose the human body. The switch from the pluripotent phenotype to a differentiated cell involves many complex signaling pathways including those involving LIF/Stat3 and the transcription factors Sox2, Nanog and Oct-4. Many nuclear receptors play an important role in the maintenance of pluripotence (ERRβ, SF-1, LRH-1, DAX-1) repression of the ES cell phenotype (RAR, RXR, GCNF) and also the differentiation of ES cells (PPARγ). Here we review the roles of the nuclear receptors involved in regulating these important processes in ES cells.
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15
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Kelly VR, Hammer GD. LRH-1 and Nanog regulate Dax1 transcription in mouse embryonic stem cells. Mol Cell Endocrinol 2011; 332:116-24. [PMID: 20937355 PMCID: PMC3018332 DOI: 10.1016/j.mce.2010.10.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 09/16/2010] [Accepted: 10/04/2010] [Indexed: 01/26/2023]
Abstract
Dax1, an atypical orphan nuclear receptor expressed in steroidogenic tissues, has recently been shown to be expressed in mouse embryonic stem (mES) cells and is required for pluripotency. While the mechanisms of transcriptional regulation of Dax1 in steroidogenic organs have been well characterized, those in mES cells have not. Here we report that 500 bp of the Dax1 gene promoter sequence are sufficient to drive expression in mES cells. In steroidogenic tissues, NR5A1 (Sf1) binds to nuclear receptor binding sites within this sequence to regulate Dax1 expression. In mES cells, while NR5A1 (Sf1) is not expressed, NR5A2 (LRH-1) expression is robust. Luciferase assays, EMSA and overexpression/knockdown studies demonstrate that LRH-1 binds the -128 site and regulates Dax1 in mES cells. Predicated on recent work indicating that Nanog binds to the Dax1 intron, we have used chromatin immunoprecipitation experiments (ChIP) to define an intronic site that is bound by Nanog. Overexpression and knockdown of Nanog in mES cells result in alteration of Dax1 expression, and luciferase assays reveal that this sequence can enhance transcription of a Dax1 reporter construct. These data indicate that LRH-1 and Nanog cooperate to regulate Dax1 expression in mES cells.
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Affiliation(s)
| | - Gary D. Hammer
- Program in Cellular and Molecular Biology
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes
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16
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von Schalburg KR, Yasuike M, Yazawa R, de Boer JG, Reid L, So S, Robb A, Rondeau EB, Phillips RB, Davidson WS, Koop BF. Regulation and expression of sexual differentiation factors in embryonic and extragonadal tissues of Atlantic salmon. BMC Genomics 2011; 12:31. [PMID: 21232142 PMCID: PMC3034696 DOI: 10.1186/1471-2164-12-31] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 01/13/2011] [Indexed: 12/14/2022] Open
Abstract
Background The products of cyp19, dax, foxl2, mis, sf1 and sox9 have each been associated with sex-determining processes among vertebrates. We provide evidence for expression of these regulators very early in salmonid development and in tissues outside of the hypothalamic-pituitary-adrenal/gonadal (HPAG) axis. Although the function of these factors in sexual differentiation have been defined, their roles in early development before sexual fate decisions and in tissues beyond the brain or gonad are essentially unknown. Results Bacterial artificial chromosomes containing salmon dax1 and dax2, foxl2b and mis were isolated and the regulatory regions that control their expression were characterized. Transposon integrations are implicated in the shaping of the dax and foxl2 loci. Splice variants for cyp19b1 and mis in both embryonic and adult tissues were detected and characterized. We found that cyp19b1 transcripts are generated that contain 5'-untranslated regions of different lengths due to cryptic splicing of the 3'-end of intron 1. We also demonstrate that salmon mis transcripts can encode prodomain products that present different C-termini and terminate before translation of the MIS hormone. Regulatory differences in the expression of two distinct aromatases cyp19a and cyp19b1 are exerted, despite transcription of their transactivators (ie; dax1, foxl2, sf1) occurring much earlier during embryonic development. Conclusions We report the embryonic and extragonadal expression of dax, foxl2, mis and other differentiation factors that indicate that they have functions that are more general and not restricted to steroidogenesis and gonadogenesis. Spliced cyp19b1 and mis transcripts are generated that may provide regulatory controls for tissue- or development-specific activities. Selection of cyp19b1 transcripts may be regulated by DAX-1, FOXL2 and SF-1 complexes that bind motifs in intron 1, or by signals within exon 2 that recruit splicing factors, or both. The potential translation of proteins bearing only the N-terminal MIS prodomain may modulate the functions of other TGF β family members in different tissues. The expression patterns of dax1 early in salmon embryogenesis implicate its role as a lineage determination factor. Other roles for these factors during embryogenesis and outside the HPAG axis are discussed.
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Affiliation(s)
- Kristian R von Schalburg
- Department of Biology, Centre for Biomedical Research, University of Victoria, Victoria, British Columbia, Canada
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Kelly VR, Xu B, Kuick R, Koenig RJ, Hammer GD. Dax1 up-regulates Oct4 expression in mouse embryonic stem cells via LRH-1 and SRA. Mol Endocrinol 2010; 24:2281-91. [PMID: 20943815 DOI: 10.1210/me.2010-0133] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Dax1 (Nr0b1) is an atypical orphan nuclear receptor that has recently been shown to play a role in mouse embryonic stem (mES) cell pluripotency. Here we describe a mechanism by which Dax1 maintains pluripotency. In steroidogenic cells, Dax1 protein interacts with the NR5A nuclear receptor steroidogenic factor 1 (Nr5a1) to inhibit transcription of target genes. In mES cells, liver receptor homolog 1 (LRH-1, Nr5a2), the other NR5A family member, is expressed, and LRH-1 has been shown to interact with Dax1. We demonstrate by coimmunoprecipitation that Dax1 is, indeed, able to form a complex with LRH-1 in mES cells. Because Dax1 was historically characterized as an inhibitor of steroidogenic factor 1-mediated transcriptional activation, we hypothesized that Dax1 would inhibit LRH-1 action in mES cells. Therefore, we examined the effect of Dax1 on the LRH-1-mediated activation of the critical ES cell factor Oct4 (Pou5f1). Chromatin immunoprecipitation localized Dax1 to the Oct4 promoter at the LRH-1 binding site, and luciferase assays together with Dax1 overexpression and knockdown experiments revealed that, rather than repress, Dax1 accentuated LRH-1-mediated activation of the Oct4 gene. Similar to our previously published studies that defined the RNA coactivator steroid receptor RNA activator as the critical mediator of Dax1 coactivation function, Dax1 augmentation of LRH-1-mediated Oct4 activation is dependent upon steroid receptor RNA activator. Finally, utilizing published chromatin immunoprecipitation data of whole-genome binding sites of LRH-1 and Dax1, we show that LRH-1 and Dax1 commonly colocalize at 288 genes (43% of LRH-1 target genes), many of which are involved in mES cell pluripotency. Thus, our results indicate that Dax1 plays an important role in the maintenance of pluripotency in mES cells through interaction with LRH-1 and transcriptional activation of Oct4 and other genes.
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Affiliation(s)
- Victoria R Kelly
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
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18
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Dax1 binds to Oct3/4 and inhibits its transcriptional activity in embryonic stem cells. Mol Cell Biol 2009; 29:4574-83. [PMID: 19528230 DOI: 10.1128/mcb.01863-08] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of blastocysts. Transcription factor Oct3/4 is an indispensable factor in the self-renewal of ES cells. In this study, we searched for a protein that would interact with Oct3/4 in ES cells and identified an orphan nuclear hormone receptor, Dax1. The association of Dax1 with Oct3/4 was mediated through the POU-specific domain of Oct3/4. Ectopic expression of Dax1 inhibited Oct3/4-mediated activation of an artificial Oct3/4-responsive promoter. Expression of Dax1 in ES cells also reduced the activities of Nanog and Rex1 promoters, while knockdown of Dax1 increased these activities. Pulldown and gel shift assays revealed that the interaction of Dax1 with Oct3/4 abolished the DNA binding activity of Oct3/4. Chromatin immunoprecipitation assay results showed that Dax1 inhibited Oct3/4 binding to the promoter/enhancer regions of Oct3/4 and Nanog. Furthermore, overexpression of Dax1 resulted in ES cell differentiation. Taken together, these data suggest that Dax1, a novel molecule interacting with Oct3/4, functions as a negative regulator of Oct3/4 in ES cells.
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Sun C, Nakatake Y, Ura H, Akagi T, Niwa H, Koide H, Yokota T. Stem cell-specific expression of Dax1 is conferred by STAT3 and Oct3/4 in embryonic stem cells. Biochem Biophys Res Commun 2008; 372:91-6. [DOI: 10.1016/j.bbrc.2008.04.154] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Accepted: 04/29/2008] [Indexed: 12/28/2022]
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Iyer AK, Zhang YH, McCabe ER. LXXLL motifs and AF-2 domain mediate SHP (NR0B2) homodimerization and DAX1 (NR0B1)-DAX1A heterodimerization. Mol Genet Metab 2007; 92:151-9. [PMID: 17686645 PMCID: PMC2065763 DOI: 10.1016/j.ymgme.2007.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Accepted: 06/20/2007] [Indexed: 11/30/2022]
Abstract
Small heterodimer partner (SHP; NR0B2) is an unusual orphan member of the nuclear receptor superfamily that functions as a corepressor of other nuclear receptors through heterodimeric interactions. Mutations in SHP are associated with mild obesity and insulin resistance. The protein domain structure of SHP is similar to Dosage-sensitive sex reversal adrenal hypoplasia congenita (AHC) critical region on the X chromosome, gene 1 (DAX1; NR0B1). Mutations in DAX1 cause AHC with associated hypogonadotropic hypogonadism. DAX1A is an alternatively spliced isoform of DAX1 that lacks the last 80 amino acids of the DAX1 C-terminal repressor domain and is replaced by a novel 10-amino acid motif. We have previously shown homodimerization of SHP and DAX1 individually, heterodimerization of DAX1 with SHP, and heterodimerization of DAX1 with DAX1A. In these studies, we investigated the domains and residues of SHP involved in SHP homodimerization and DAX1-SHP heterodimerization and also further characterized DAX1-DAX1 homodimerization and DAX1-DAX1A heterodimerization. We showed involvement of the SHP LXXLL motifs and AF-2 domain in SHP homodimerization and DAX1-SHP heterodimerization. We demonstrated redundancy of the LXXLL motifs in DAX1 homodimerization. While DAX1A subcellular localization is mostly cytoplasmic, DAX1-DAX1A heterodimers existed in the nucleus, suggesting differential functions for DAX1A in each compartment. We showed that the AF-2 domain of DAX1 is involved in DAX1-DAX1A heterodimerization. These results indicate that NR0B family members use similar mechanisms for homodimerization as well as heterodimerization. These resemble coactivator-receptor interactions that may have potential functional consequences for molecular mechanisms of the NR0B family.
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Affiliation(s)
- Anita K. Iyer
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Corresponding author: E.R.B. McCabe, M.D., Ph.D., Department of Pediatrics, 22-412 MDCC, David Geffen School of Medicine at UCLA, 10833 Le Conte Avenue, Los Angeles, CA, 90095-1752, USA. Phone 310-825-5095, Fax 310-206-4584, Email
| | - Yao-Hua Zhang
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Edward R.B. McCabe
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Mattel Children's Hospital at UCLA
- UCLA Molecular Biology Institute, Los Angeles, CA, USA
- Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, UCLA, Los Angeles, CA, USA
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Abstract
DAX1 (NR0B1) is a nuclear receptor with a characteristic C-terminal ligand binding domain, but an atypical DNA binding domain. Mutations in the DAX1 gene cause adrenal hypoplasia congenita (AHC) establishing its biological importance. Recent studies highlight the complexities of DAX1 regulation and function. There is considerable phenotypic variability in AHC suggesting the existence of DAX1 modifier genes and environmental influences on DAX1 function. The findings of an alternatively spliced DAX1A, more common than DAX1 in all tissues except testis, of DAX1 homodimers, and of DAX1 heterodimers with a number of transcription factor partners including DAX1A and SHP point to an expanded transcription regulatory network under DAX1 control. Model organisms (mice and zebrafish) are being used to identify other DAX1 functions and modifier genes to understand the pathogenesis of AHC and the lack of genotype-phenotype correlation.
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Affiliation(s)
- Edward R B McCabe
- Mattel Children's Hospital at UCLA, Los Angeles, CA 90095-1752, United States.
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22
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Abstract
PURPOSE The feasibility of culturing murine adrenal cortical cells before transplantation was investigated in this study. METHOD Primary murine adrenal cortical cells were maintained in either fetal bovine and horse sera-containing media or serum-free media. Real-time polymerase chain reaction was used to quantify the levels of adrenal cortical gene expression in the cultured cells. RESULTS The use of sera-containing media led to the growth of many cells in the culture, but the expression of Sf-1, Dax-1, and Cyp11b1 in such cultures declined rapidly. In contrast, there was no significant cell growth in the serum-free culture medium. Culturing murine adrenal cortical cells in the serum-free medium resulted in higher levels of Sf-1, Dax-1, and Cyp11b1 gene expression. In the serum-free medium, adrenal cortical cells also responded to adrenocorticotropic hormone by increasing the expression of Cyp11b1 and suppressing the expression of Dax-1 in a dose-dependent manner. The addition of basic fibroblast growth factor to the serum-free medium maintained the expression of Sf-1, Dax-1, and Cyp11b1 for 4 weeks. CONCLUSION Adrenal cortical cells isolated from adult mice were successfully maintained in a serum-free culture medium with basic fibroblast growth factor. This culture system may be suitable for further manipulation of adrenal cortical cells in vitro before transplantation.
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Affiliation(s)
- Yinting Chu
- Department of Bioengineering, Henry Samueli School of Engineering, University of California, Los Angeles, CA 90095, USA
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23
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Niakan KK, Davis EC, Clipsham RC, Jiang M, Dehart DB, Sulik KK, McCabe ERB. Novel role for the orphan nuclear receptor Dax1 in embryogenesis, different from steroidogenesis. Mol Genet Metab 2006; 88:261-71. [PMID: 16466956 DOI: 10.1016/j.ymgme.2005.12.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Accepted: 12/15/2005] [Indexed: 11/26/2022]
Abstract
Cytomegalic adrenal hypoplasia congenita (AHC) is an X-linked disease caused by mutations in DAX1-encoding gene NR0B1, previously thought to function primarily in steroidogenesis. We sought to determine the expression pattern for Dax1 along with known network partners in early embryogenesis and to determine a steroidogenic capacity for the embryo prior to the establishment of the urogenital ridge at embryonic day 9 (E9). Here, we report that murine Dax1 is a unique marker in early embryonic development, distinguishing the extraembryonic (proximal) endoderm from the remainder of the developing embryo. We showed that Wilms tumor 1, steroidogenic factor 1, and estrogen receptor beta were expressed throughout the embryo, but the progesterone, estrogen alpha and androgen receptors, cytochrome P450 (Cyp11a1) and Nur77 were not observed in any of the embryonic layers. Lack of Cyp11A1 expression at this stage confirmed an absence of inherent steroidogenic capacity for the early embryo. The role of Nr0b1 in embryonic stem (ES) cells was investigated using siRNA knockdown, resulting in differentiation toward endoderm-like fate. Nr0b1 conditional knockout in ES cells led to differentiation, confirming our knockdown results. Our investigations suggest that Nr0b1 functions in a novel role in the maintenance of a relatively undifferentiated state. Our results further suggest that the failure of conventional murine Nr0b1 knockout attempts may be due to disregulated differentiation.
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Affiliation(s)
- Kathy K Niakan
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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24
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Iyer AK, Zhang YH, McCabe ERB. Dosage-sensitive sex reversal adrenal hypoplasia congenita critical region on the X chromosome, gene 1 (DAX1) (NR0B1) and small heterodimer partner (SHP) (NR0B2) form homodimers individually, as well as DAX1-SHP heterodimers. Mol Endocrinol 2006; 20:2326-42. [PMID: 16709599 DOI: 10.1210/me.2005-0383] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Dosage-sensitive sex reversal adrenal hypoplasia congenita critical region on the X chromosome, gene 1 (DAX1) (NR0B1), and small heterodimer partner (SHP) (NR0B2) are atypical nuclear receptor superfamily members that function primarily as corepressors through heterodimeric interactions with other nuclear receptors. Mutations in DAX1 cause adrenal hypoplasia congenita, and mutations in SHP lead to mild obesity and insulin resistance, but the mechanisms are unclear. We investigated the existence and subcellular localization of DAX1 and SHP homodimers and the dynamics of homodimerization. We demonstrated DAX1 homodimerization in the nucleus and cytoplasm, and dissociation of DAX1 homodimers upon heterodimerization with steroidogenic factor 1 (SF1) or ligand-activated estrogen receptor-alpha (ERalpha). DAX1 homodimerization involved an interaction between its amino and carboxy termini involving its LXXLL motifs and activation function (AF)-2 domain. We observed SHP homodimerization in the nucleus of mammalian cells and showed dissociation of SHP homodimers upon heterodimerization with ligand-activated ERalpha. We observed DAX1-SHP heterodimerization in the nucleus of mammalian cells and demonstrated the involvement of the LXXLL motifs and AF-2 domain of DAX1 in this interaction. We further demonstrate heterodimerization of DAX1 with its alternatively spliced isoform, DAX1A. This is the first evidence of homodimerization of individual members of the unusual NR0B nuclear receptor family and heterodimerization between its members. Our results suggest that DAX1 forms antiparallel homodimers through the LXXLL motifs and AF-2 domain. These homodimers may function as holding reservoirs in the absence of heterodimeric partners. The formation of DAX1 and SHP homodimers and DAX1-SHP and DAX1-DAX1A heterodimers suggests the possibility of novel functions independent of their coregulator roles, suggesting additional complexity in the molecular mechanisms of DAX1 and SHP action.
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Affiliation(s)
- Anita K Iyer
- Department of Human Genetics, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095-1752, USA
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25
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Ho J, Zhang YH, Huang BL, McCabe ERB. NR0B1A: an alternatively spliced form of NR0B1. Mol Genet Metab 2004; 83:330-6. [PMID: 15589120 DOI: 10.1016/j.ymgme.2004.10.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2004] [Accepted: 10/13/2004] [Indexed: 10/26/2022]
Abstract
The orphan nuclear receptor DAX1 (dosage-sensitive sex reversal-AHC critical region on the X chromosome gene 1), encoded by the NR0B1 gene, plays important roles in the development of the hypothalamic-pituitary-adrenal/gonadal (HPAG) axis as well as in sex determination. Mutations in NR0B1 cause the X-linked cytomegalic form of adrenal hypoplasia congenita (AHC), and associated hypogonadotropic hypogonadism (HH). Over-expression of NR0B1 results in sex reversal in mice and duplication of the 160kb DSS locus in human patients results in a sex-reversed phenotype (XY females). The purpose of these investigations was to determine if alternatively spliced forms of NR0B1 existed. Analysis of expressed sequence tag data predicted a truncated isoform of DAX1. We confirmed the presence of an alternatively spliced form of NR0B1, which we will refer to as NR0B1A, by reverse transcriptase-polymerase chain reaction (RT-PCR), and will refer to the deduced protein isoform as DAX1A. Sequencing of the NR0B1A cDNA revealed slight differences from the recently described splice form, DAX1alpha. NR0B1A is encoded by NR0B1 exon 1 and exon 2A located within the 3385 nt intron between NR0B1 exons 1 and 2. Exon 2A includes 35 nt of coding sequence. NR0B1A encodes a deduced protein sequence, DAX1A, of 400 amino acids compared with 470 amino acids for DAX1. RT-PCR detected expression of NR0B1A in adrenal gland, testis, ovary, and pancreas. The identification of NR0B1A and the deduced DAX1A requires reinterpretation of many previous experiments involving expression and knockout of NR0B1 and DAX1.
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Affiliation(s)
- John Ho
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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Rao M. Conserved and divergent paths that regulate self-renewal in mouse and human embryonic stem cells. Dev Biol 2004; 275:269-86. [PMID: 15501218 DOI: 10.1016/j.ydbio.2004.08.013] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2004] [Revised: 08/10/2004] [Accepted: 08/10/2004] [Indexed: 01/10/2023]
Abstract
The past few years have seen remarkable progress in our understanding of embryonic stem cell (ES cell) biology. The necessity of examining human ES cells in culture, coupled with the wealth of genomic data and the multiplicity of cell lines available, has enabled researchers to identify critical conserved pathways regulating self-renewal and identify markers that tightly correlate with the ES cell state. Comparison across species has suggested additional pathways likely to be important in long-term self-renewal of ES cells including heterochronic genes, microRNAs, genes involved in telomeric regulation, and polycomb repressors. In this review, we have discussed information on molecules known to be important in ES cell self-renewal or blastocyst development and highlighted known differences between mouse and human ES cells. We suggest that several additional pathways required for self-renewal remain to be discovered and these likely include genes involved in antisense regulation, microRNAs, as well as additional global repressive pathways and novel genes. We suggest that cross species comparisons using large-scale genomic analysis tools are likely to reveal conserved and divergent paths required for ES cell self-renewal and will allow us to derive ES lines from species and strains where this has been difficult.
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Affiliation(s)
- Mahendra Rao
- Stem Cell Section, Laboratory of Neurosciences, Gerontology Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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Iyer AK, McCabe ERB. Molecular mechanisms of DAX1 action. Mol Genet Metab 2004; 83:60-73. [PMID: 15464421 DOI: 10.1016/j.ymgme.2004.07.018] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2004] [Revised: 07/12/2004] [Accepted: 07/13/2004] [Indexed: 11/24/2022]
Abstract
DAX1 (dosage sensitive sex reversal (DSS), adrenal hypoplasia congenita (AHC) critical region on the X chromosome, gene 1) encoded by the gene NR0B1, is an unusual orphan nuclear receptor that when mutated causes AHC with associated hypogonadotropic hypogonadism (HH), and when duplicated causes DSS. DAX1 expression has been shown in all regions of the hypothalamic-pituitary-adrenal-gonadal (HPAG) axis during development and in adult tissues, suggesting a critical role for DAX1 in the normal development and function of this axis. Steroidogenic factor 1 (SF1, NR5A1) knockout mice show similar developmental defects as AHC and HH patients, but paradoxically, DAX1 is a negative coregulator of SF1 transactivation. The function of DAX1 as an antagonist of SF1 in gonadal development is consistent with the fact that in humans, duplication of the region of the X chromosome containing DAX1 causes a similar phenotype as mutations in SF1. However, how disruption of DAX1 leads to adrenal, hypothalamic, and pituitary developmental defects similar to SF1 disruption remains to be clarified. The exact mechanism of DAX1 action in each of these tissues during adulthood and critical stages of development are not fully understood. Recent evidence suggests a broader functional role for DAX1 as a negative coregulator of estrogen receptor (ER, NR3A1-2), liver receptor homologue-1 (LRH-1, NR5A2), androgen receptor (AR, NR3C4), and progesterone receptor (PR, NR3C3), each by distinct repression mechanisms. DAX1 may have pleiotropic roles in addition to its function as a negative regulator of steroidogenesis during the development and adult function of the HPAG axis.
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MESH Headings
- Animals
- DAX-1 Orphan Nuclear Receptor
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- DNA-Binding Proteins/physiology
- Female
- Gene Expression Regulation, Developmental
- Homeodomain Proteins
- Humans
- Hypothalamo-Hypophyseal System/physiology
- Male
- Mice
- Ovary/growth & development
- Ovary/physiology
- Pituitary-Adrenal System/physiology
- Receptors, Androgen/genetics
- Receptors, Androgen/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Receptors, Progesterone/genetics
- Receptors, Progesterone/metabolism
- Receptors, Retinoic Acid/physiology
- Repressor Proteins/physiology
- Sex Determination Processes
- Steroidogenic Factor 1
- Testis/growth & development
- Testis/physiology
- Transcription Factors/genetics
- Transcription Factors/metabolism
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Affiliation(s)
- Anita K Iyer
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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28
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Abstract
DAX1 encoded by NR0B1, when mutated, is responsible for X-linked adrenal hypoplasia congenita (AHC). AHC is due to failure of the adrenal cortex to develop normally and is fatal if untreated. When duplicated, this gene is associated with an XY sex-reversed phenotype. DAX1 expression is present during development of the steroidogenic hypothalamic-pituitary-adrenal-gonadal (HPAG) axis and persists into adult life. Despite recognition of the crucial role for DAX1, its function remains largely undefined. The phenotypes of patients and animal models are complex and not always in agreement. Investigations using cell lines have proved difficult to interpret, possibly reflecting cell line choices and their limited characterization. We will review the efforts of our group and others to identify appropriate cell lines for optimizing ex vivo analysis of NR0B1 function throughout development. We will examine the role of DAX1 and its network partners in development of the hypothalamic-pituitary-adrenal/gonadal axis (HPAG) using a variety of different types of investigations, including those in model organisms. This network analysis will help us to understand normal and abnormal development of the HPAG. In addition, these studies permit identification of candidate genes for human inborn errors of HPAG development.
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