1
|
Legrand JMD, Hobbs RM. Defining Gene Function in Spermatogonial Stem Cells Through Conditional Knockout Approaches. Methods Mol Biol 2023; 2656:261-307. [PMID: 37249877 DOI: 10.1007/978-1-0716-3139-3_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Mammalian male fertility is maintained throughout life by a population of self-renewing mitotic germ cells known as spermatogonial stem cells (SSCs). Much of our current understanding regarding the molecular mechanisms underlying SSC activity is derived from studies using conditional knockout mouse models. Here, we provide a guide for the selection and use of mouse strains to develop conditional knockout models for the study of SSCs, as well as their precursors and differentiation-committed progeny. We describe Cre recombinase-expressing strains, breeding strategies to generate experimental groups, and treatment regimens for inducible knockout models and provide advice for verifying and improving conditional knockout efficiency. This resource can be beneficial to those aiming to develop conditional knockout models for the study of SSC development and postnatal function.
Collapse
Affiliation(s)
- Julien M D Legrand
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, Australia
| | - Robin M Hobbs
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia.
- Department of Molecular and Translational Sciences, Monash University, Clayton, VIC, Australia.
| |
Collapse
|
2
|
Bloom JC, Loehr AR, Schimenti JC, Weiss RS. Germline genome protection: implications for gamete quality and germ cell tumorigenesis. Andrology 2019; 7:516-526. [PMID: 31119900 DOI: 10.1111/andr.12651] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Germ cells have a unique and critical role as the conduit for hereditary information and therefore employ multiple strategies to protect genomic integrity and avoid mutations. Unlike somatic cells, which often respond to DNA damage by arresting the cell cycle and conducting DNA repair, germ cells as well as long-lived pluripotent stem cells typically avoid the use of error-prone repair mechanisms and favor apoptosis, reducing the risk of genetic alterations. Testicular germ cell tumors, the most common cancers of young men, arise from pre-natal germ cells. OBJECTIVES To summarize the current understanding of DNA damage response mechanisms in pre-meiotic germ cells and to discuss how they impact both the origins of testicular germ cell tumors and their remarkable responsiveness to genotoxic chemotherapy. MATERIALS AND METHODS We conducted a review of literature gathered from PubMed regarding the DNA damage response properties of testicular germ cell tumors and the germ cells from which they arise, as well as the influence of these mechanisms on therapeutic responses by testicular germ cell tumors. RESULTS AND DISCUSSION This review provides a comprehensive evaluation of how the developmental origins of male germ cells and their inherent germ cell-like DNA damage response directly impact the development and therapeutic sensitivity of testicular germ cell tumors. CONCLUSIONS The DNA damage response of germ cells directly impacts the development and therapeutic sensitivity of testicular germ cell tumors. Recent advances in the study of primordial germ cells, post-natal mitotically dividing germ cells, and pluripotent stem cells will allow for new investigations into the initiation, progression, and treatment of testicular germ cell tumors.
Collapse
Affiliation(s)
- J C Bloom
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| | - A R Loehr
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| | - J C Schimenti
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| | - R S Weiss
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, USA
| |
Collapse
|
3
|
The Role of DNA/Histone Modifying Enzymes and Chromatin Remodeling Complexes in Testicular Germ Cell Tumors. Cancers (Basel) 2018; 11:cancers11010006. [PMID: 30577487 PMCID: PMC6357018 DOI: 10.3390/cancers11010006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/22/2022] Open
Abstract
It is well established that cancer cells exhibit alterations in chromatin structure and accessibility. Indeed, the dysregulation of many protein-coding players with enzymatic activity (DNA and histone-modifying enzymes) and chromatin remodelers have been depicted in various tumor models in recent years. Still, little attention has been directed towards testicular germ cell tumors (TGCTs)-representing the most common neoplasm among young adult Caucasian men-with most studies focusing on exploring the role of DNA methyltransferases (DNMTs) and DNA demethylases (TETs). TGCTs represent a complex tumor model, associated with developmental and embryogenesis-related phenomena, and display seldom (cyto)genetic aberrations, leaving room for Epigenetics to explain such morphological and clinical diversity. Herein, we have summarized the major findings that were reported in literature regarding the dysregulation of DNA/histone-modifying enzymes and chromatin remodelers in TGCTs. Additionally, we performed in silico analysis of The Cancer Genome Atlas database to find the most relevant of those players in TGCTs. We concluded that several DNA/histone-modifying enzymes and chromatin remodelers may serve as biomarkers for subtyping, dictating prognosis and survival, and, possibly, for serving as targets of directed, less toxic therapies.
Collapse
|
4
|
Hamer G, de Rooij DG. Mutations causing specific arrests in the development of mouse primordial germ cells and gonocytes. Biol Reprod 2018; 99:75-86. [DOI: 10.1093/biolre/ioy075] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 03/22/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Geert Hamer
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Dirk G de Rooij
- Center for Reproductive Medicine, Amsterdam Research Institute Reproduction and Development, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
5
|
Metabolic Reprogramming, Autophagy, and Reactive Oxygen Species Are Necessary for Primordial Germ Cell Reprogramming into Pluripotency. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4745252. [PMID: 28757909 PMCID: PMC5516724 DOI: 10.1155/2017/4745252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/07/2017] [Accepted: 05/25/2017] [Indexed: 12/23/2022]
Abstract
Cellular reprogramming is accompanied by a metabolic shift from oxidative phosphorylation (OXPHOS) toward glycolysis. Previous results from our laboratory showed that hypoxia alone is able to reprogram primordial germ cells (PGCs) into pluripotency and that this action is mediated by hypoxia-inducible factor 1 (HIF1). As HIF1 exerts a myriad of actions by upregulating several hundred genes, to ascertain whether the metabolic switch toward glycolysis is solely responsible for reprogramming, PGCs were cultured in the presence of a pyruvate kinase M2 isoform (PKM2) activator, or glycolysis was promoted by manipulating PPARγ. Conversely, OXPHOS was stimulated by inhibiting PDK1 activity in normoxic or in hypoxic conditions. Inhibition or promotion of autophagy and reactive oxygen species (ROS) production was performed to ascertain their role in cell reprogramming. Our results show that a metabolic shift toward glycolysis, autophagy, and mitochondrial inactivation and an early rise in ROS levels are necessary for PGC reprogramming. All of these processes are governed by HIF1/HIF2 balance and strict intermediate Oct4 levels. Histone acetylation plays a role in reprogramming and is observed under all reprogramming conditions. The pluripotent cells thus generated were unable to self-renew, probably due to insufficient Blimp1 downregulation and a lack of Klf4 and cMyc expression.
Collapse
|
6
|
Fontán-Lozano A, Capilla-Gonzalez V, Aguilera Y, Mellado N, Carrión AM, Soria B, Hmadcha A. Impact of transient down-regulation of DREAM in human embryonic stem cell pluripotency: The role of DREAM in the maintenance of hESCs. Stem Cell Res 2016; 16:568-78. [PMID: 26999760 DOI: 10.1016/j.scr.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 02/25/2016] [Accepted: 03/03/2016] [Indexed: 12/23/2022] Open
Abstract
Little is known about the functions of downstream regulatory element antagonist modulator (DREAM) in embryonic stem cells (ESCs). However, DREAM interacts with cAMP response element-binding protein (CREB) in a Ca(2+)-dependent manner, preventing CREB binding protein (CBP) recruitment. Furthermore, CREB and CBP are involved in maintaining ESC self-renewal and pluripotency. However, a previous knockout study revealed the protective function of DREAM depletion in brain aging degeneration and that aging is accompanied by a progressive decline in stem cells (SCs) function. Interestingly, we found that DREAM is expressed in different cell types, including human ESCs (hESCs), human adipose-derived stromal cells (hASCs), human bone marrow-derived stromal cells (hBMSCs), and human newborn foreskin fibroblasts (hFFs), and that transitory inhibition of DREAM in hESCs reduces their pluripotency, increasing differentiation. We stipulate that these changes are partly mediated by increased CREB transcriptional activity. Overall, our data indicates that DREAM acts in the regulation of hESC pluripotency and could be a target to promote or prevent differentiation in embryonic cells.
Collapse
Affiliation(s)
- A Fontán-Lozano
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Sevilla 41092, Spain
| | - V Capilla-Gonzalez
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Sevilla 41092, Spain
| | - Y Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Sevilla 41092, Spain
| | - N Mellado
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Sevilla 41092, Spain
| | - A M Carrión
- División de Neurociencias, Universidad Pablo de Olavide de Sevilla, Sevilla 41013, Spain
| | - B Soria
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Sevilla 41092, Spain; CIBER de Diabetes y Enfermedades Metabólica asociada (CIBERDEM), Madrid 28029, Spain
| | - A Hmadcha
- Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Sevilla 41092, Spain; CIBER de Diabetes y Enfermedades Metabólica asociada (CIBERDEM), Madrid 28029, Spain.
| |
Collapse
|
7
|
Abstract
Alkaline phosphatase is an enzyme commonly expressed in almost all living organisms. In humans and other mammals, determinations of the expression and activity of alkaline phosphatase have frequently been used for cell determination in developmental studies and/or within clinical trials. Alkaline phosphatase also seems to be one of the key markers in the identification of pluripotent embryonic stem as well as related cells. However, alkaline phosphatases exist in some isoenzymes and isoforms, which have tissue specific expressions and functions. Here, the role of alkaline phosphatase as a stem cell marker is discussed in detail. First, we briefly summarize contemporary knowledge of mammalian alkaline phosphatases in general. Second, we focus on the known facts of its role in and potential significance for the identification of stem cells.
Collapse
|
8
|
Li M, Zhao H, Wei J, Zhang J, Hong Y. Medaka vasa gene has an exonic enhancer for germline expression. Gene 2015; 555:403-8. [DOI: 10.1016/j.gene.2014.11.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 11/04/2014] [Accepted: 11/15/2014] [Indexed: 11/26/2022]
|
9
|
Zhu R, Iacovino M, Mahen E, Kyba M, Matin A. Transcripts that associate with the RNA binding protein, DEAD-END (DND1), in embryonic stem (ES) cells. BMC Mol Biol 2011; 12:37. [PMID: 21851623 PMCID: PMC3167746 DOI: 10.1186/1471-2199-12-37] [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: 05/05/2011] [Accepted: 08/18/2011] [Indexed: 12/11/2022] Open
Abstract
Background The RNA binding protein, DEAD END (DND1), is essential for maintaining viable germ cells in vertebrates. It is also a testicular germ cell tumor susceptibility factor in mice. DND1 has been shown to interact with the 3'-untranslated region (3'-UTR) of mRNAs such as P27 and LATS2. Binding of DND1 to the 3'-UTRs of these transcripts blocks the inhibitory function of microRNAs (miRNA) from these transcripts and in this way DND1 helps maintain P27 and LATS2 protein expression. We found that DND1 is also expressed in embryonic stem (ES) cells. Because ES cells share similar gene expression patterns as germ cells, we utilized ES cells to identify additional candidate mRNAs that associate with DND1. Results ES cells are readily amenable to genetic modification and easier to culture in vitro compared to germ cells. Therefore, for the purpose of our study, we made a genetically modified, stable, human embryonic stem (hES) cell line that expresses hemagluttinin (HA)-tagged DND1 in a doxycycline (dox) regulatable manner. This line expresses modest levels of HA-DND1 and serves as a good system to study DND1 function in vitro. We used this stable cell line to identify the transcripts that physically interact with DND1. By performing ribonucleoprotein immunoprecipitation (RIP) followed by RT-PCR, we identified that transcripts encoding pluripotency factors (OCT4, SOX2, NANOG, LIN28), cell cycle regulators (TP53, LATS2) and apoptotic factors (BCLX, BAX) are specifically associated with the HA-DND1 ribonucleoprotein complex. Surprisingly, in many cases, bioinformatics analysis of the pulled-down transcripts did not reveal the presence of known DND1 interacting motifs. Conclusions Our results indicate that the inducible ES cell line system serves as a suitable in vitro system to identify the mRNA targets of DND1. The RIP-RT results hint at the broad spectrum of mRNA targets that interact with DND1 in ES cells. Based on what is known about DND1 function, our results suggest that DND1 may impose another level of translational regulation to modulate expression of critical factors in ES cells.
Collapse
Affiliation(s)
- Rui Zhu
- Department of Genetics, University of Texas, MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | | | | | | |
Collapse
|
10
|
Eo J, Shin H, Kwon S, Song H, Murphy KM, Lim HJ. Complex ovarian defects lead to infertility in Etv5-/- female mice. Mol Hum Reprod 2011; 17:568-76. [DOI: 10.1093/molehr/gar021] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
11
|
|
12
|
Bedford DC, Kasper LH, Fukuyama T, Brindle PK. Target gene context influences the transcriptional requirement for the KAT3 family of CBP and p300 histone acetyltransferases. Epigenetics 2010; 5:9-15. [PMID: 20110770 DOI: 10.4161/epi.5.1.10449] [Citation(s) in RCA: 216] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
One general principle of gene regulation is that DNA-binding transcription factors modulate transcription by recruiting cofactors that modify histones and chromatin structure. A second implicit principle is that a particular cofactor is necessary at all the target genes where the cofactor is recruited. Increasingly, these principles do not appear to be absolute, as experimentally defined relationships between transcription, cofactors and chromatin modification grow in complexity. The KAT3 histone acetyltransferases CREB binding protein (CBP) and p300 have at least 400 interacting protein partners, thereby acting as hubs in gene regulatory networks. Studies using mutant primary cells indicate that the occurrence of CBP and p300 at any given target gene sometimes correlates with, rather than dictates transcription. This suggests that there are unexpected levels of redundancy between CBP/p300 and other unrelated coactivators, or that CBP/p300 recruitment may sometimes be coincidental. A transcription factor may therefore recruit the same group of coactivators as part of its "toolbox", but it is the characteristics of the individual target gene that determine which coactivation "tools" are required for its transcription.
Collapse
Affiliation(s)
- David C Bedford
- Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | | |
Collapse
|
13
|
Weber S, Eckert D, Nettersheim D, Gillis AJM, Schäfer S, Kuckenberg P, Ehlermann J, Werling U, Biermann K, Looijenga LHJ, Schorle H. Critical function of AP-2 gamma/TCFAP2C in mouse embryonic germ cell maintenance. Biol Reprod 2009; 82:214-23. [PMID: 19776388 DOI: 10.1095/biolreprod.109.078717] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Formation of the germ cell lineage involves multiple processes, including repression of somatic differentiation and reacquisition of pluripotency as well as a unique epigenetic constitution. The transcriptional regulator Prdm1 has been identified as a main coordinator of this process, controlling epigenetic modification and gene expression. Here we report on the expression pattern of the transcription factor Tcfap2c, a putative downstream target of Prdm1, during normal mouse embryogenesis and the consequences of its specific loss in primordial germ cells (PGCs) and their derivatives. Tcfap2c is expressed in PGCs from Embryonic Day 7.25 (E 7.25) up to E 12.5, and targeted disruption resulted in sterile animals, both male and female. In the mutant animals, PGCs were specified but were lost around E 8.0. PGCs generated in vitro from embryonic stem cells lacking TCFAP2C displayed induction of Prdm1 and Dppa3. Upregulation of Hoxa1, Hoxb1, and T together with lack of expression of germ cell markers such Nanos3, Dazl, and Mutyh suggested that the somatic gene program is induced in TCFAP2C-deficient PGCs. Repression of TCFAP2C in TCam-2, a human PGC-resembling seminoma cell line, resulted in specific upregulation of HOXA1, HOXB1, MYOD1, and HAND1, indicative of mesodermal differentiation. Expression of genes indicative of ectodermal, endodermal, or extraembryonic differentiation, as well as the finding of no change to epigenetic modifications, suggested control by other factors. Our results implicate Tcfap2c as an important effector of Prdm1 activity that is required for PGC maintenance, most likely mediating Prdm1-induced suppression of mesodermal differentiation.
Collapse
Affiliation(s)
- Susanne Weber
- Institute of Pathology, Department of Developmental Pathology, University of Bonn, Bonn, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|