1
|
Nelson KA, Lenhart KF, Anllo L, DiNardo S. The Drosophila hematopoietic niche assembles through collective cell migration controlled by neighbor tissues and Slit-Robo signaling. eLife 2025; 13:RP100455. [PMID: 39750120 PMCID: PMC11698496 DOI: 10.7554/elife.100455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2025] Open
Abstract
Niches are often found in specific positions in tissues relative to the stem cells they support. Consistency of niche position suggests that placement is important for niche function. However, the complexity of most niches has precluded a thorough understanding of how their proper placement is established. To address this, we investigated the formation of a genetically tractable niche, the Drosophila Posterior Signaling Center (PSC), the assembly of which had not been previously explored. This niche controls hematopoietic progenitors of the lymph gland (LG). PSC cells were previously shown to be specified laterally in the embryo, but ultimately reside dorsally, at the LG posterior. Here, using live-imaging, we show that PSC cells migrate as a tight collective and associate with multiple tissues during their trajectory to the LG posterior. We find that Slit emanating from two extrinsic sources, visceral mesoderm and cardioblasts, is required for the PSC to remain a collective, and for its attachment to cardioblasts during migration. Without proper Slit-Robo signaling, PSC cells disperse, form aberrant contacts, and ultimately fail to reach their stereotypical position near progenitors. Our work characterizes a novel example of niche formation and identifies an extrinsic signaling relay that controls precise niche positioning.
Collapse
Affiliation(s)
- Kara A Nelson
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Institute for Regenerative Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Kari F Lenhart
- Department of Biology, Drexel UniversityPhiladelphiaUnited States
| | - Lauren Anllo
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Institute for Regenerative Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Stephen DiNardo
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Institute for Regenerative Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| |
Collapse
|
2
|
Nelson KA, Lenhart KF, Anllo L, DiNardo S. The Drosophila hematopoietic niche assembles through collective cell migration controlled by neighbor tissues and Slit-Robo signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.21.600069. [PMID: 38979182 PMCID: PMC11230208 DOI: 10.1101/2024.06.21.600069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Niches are often found in specific positions in tissues relative to the stem cells they support. Consistency of niche position suggests that placement is important for niche function. However, the complexity of most niches has precluded a thorough understanding of how their proper placement is established. To address this, we investigated the formation of a genetically tractable niche, the Drosophila Posterior Signaling Center (PSC), the assembly of which had not been previously explored. This niche controls hematopoietic progenitors of the lymph gland (LG). PSC cells were previously shown to be specified laterally in the embryo, but ultimately reside dorsally, at the LG posterior. Here, using live-imaging, we show that PSC cells migrate as a tight collective and associate with multiple tissues during their trajectory to the LG posterior. We find that Slit emanating from two extrinsic sources, visceral mesoderm and cardioblasts, is required for the PSC to remain a collective, and for its attachment to cardioblasts during migration. Without proper Slit-Robo signaling, PSC cells disperse, form aberrant contacts, and ultimately fail to reach their stereotypical position near progenitors. Our work characterizes a novel example of niche formation and identifies an extrinsic signaling relay that controls precise niche positioning.
Collapse
Affiliation(s)
- Kara A Nelson
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd. Philadelphia, PA 19104, United States
- Institute for Regenerative Medicine at the University of Pennsylvania, 3400 Civic Center Blvd. Philadelphia, PA 19104, United States
| | - Kari F Lenhart
- Department of Biology, Drexel University, 3245 Chestnut St. Philadelphia, PA 19104, United States
| | - Lauren Anllo
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd. Philadelphia, PA 19104, United States
- Institute for Regenerative Medicine at the University of Pennsylvania, 3400 Civic Center Blvd. Philadelphia, PA 19104, United States
- Present address: Department of Biology, East Carolina University, 458 Science & Tech Bldg. Greenville, NC 27858, United States
| | - Stephen DiNardo
- Department of Cell and Developmental Biology, Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd. Philadelphia, PA 19104, United States
- Institute for Regenerative Medicine at the University of Pennsylvania, 3400 Civic Center Blvd. Philadelphia, PA 19104, United States
| |
Collapse
|
3
|
Kong R, Zhao H, Li J, Ma Y, Li N, Shi L, Li Z. A regulatory loop of JAK/STAT signalling and its downstream targets represses cell fate conversion and maintains male germline stem cell niche homeostasis. Cell Prolif 2024; 57:e13648. [PMID: 38987866 PMCID: PMC11471429 DOI: 10.1111/cpr.13648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/03/2024] [Accepted: 04/11/2024] [Indexed: 07/12/2024] Open
Abstract
A specialised microenvironment, termed niche, provides extrinsic signals for the maintenance of residential stem cells. However, how residential stem cells maintain niche homeostasis and whether stromal niche cells could convert their fate into stem cells to replenish lost stem cells upon systemic stem cell loss remain largely unknown. Here, through systemic identification of JAK/STAT downstream targets in adult Drosophila testis, we show that Escargot (Esg), a member of the Snail family of transcriptional factors, is a putative JAK/STAT downstream target. esg is intrinsically required in cyst stem cells (CySCs) but not in germline stem cells (GSCs). esg depletion in CySCs results in CySC loss due to differentiation and non-cell autonomous GSC loss. Interestingly, hub cells are gradually lost by delaminating from the hub and converting into CySCs in esg-defective testes. Mechanistically, esg directly represses the expression of socs36E, the well-known downstream target and negative regulator of JAK/STAT signalling. Finally, further depletion of socs36E completely rescues the defects observed in esg-defective testes. Collectively, JAK/STAT target Esg suppresses SOCS36E to maintain CySC fate and repress niche cell conversion. Thus, our work uncovers a regulatory loop between JAK/STAT signalling and its downstream targets in controlling testicular niche homeostasis under physiological conditions.
Collapse
Affiliation(s)
- Ruiyan Kong
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| | - Hang Zhao
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| | - Juan Li
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| | - Yankun Ma
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| | - Ningfang Li
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| | - Lin Shi
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| | - Zhouhua Li
- Laboratory of Stem Cell Biology, College of Life SciencesCapital Normal UniversityBeijingChina
| |
Collapse
|
4
|
Li YR, Ling LB, Chao A, Fugmann SD, Yang SY. Transient chromatin decompaction at the start of D. melanogaster male embryonic germline development. Life Sci Alliance 2024; 7:e202302401. [PMID: 38991729 PMCID: PMC11239976 DOI: 10.26508/lsa.202302401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 06/28/2024] [Accepted: 07/01/2024] [Indexed: 07/13/2024] Open
Abstract
Embryonic germ cells develop rapidly to establish the foundation for future developmental trajectories, and in this process, they make critical lineage choices including the configuration of their unique identity and a decision on sex. Here, we use single-cell genomics patterns for the entire embryonic germline in Drosophila melanogaster along with the somatic gonadal precursors after embryonic gonad coalescence to investigate molecular mechanisms involved in the setting up and regulation of the germline program. Profiling of the early germline chromatin landscape revealed sex- and stage-specific features. In the male germline immediately after zygotic activation, the chromatin structure underwent a brief remodeling phase during which nucleosome density was lower and deconcentrated from promoter regions. These findings echoed enrichment analysis results of our genomics data in which top candidates were factors with the ability to mediate large-scale chromatin reorganization. Together, they point to the importance of chromatin regulation in the early germline and raise the possibility of a conserved epigenetic reprogramming-like process required for proper initiation of germline development.
Collapse
Affiliation(s)
- Yi-Ru Li
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Li Bin Ling
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Angel Chao
- Department of Obstetrics and Gynecology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Sebastian D Fugmann
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Nephrology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Shu Yuan Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Obstetrics and Gynecology, Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan
| |
Collapse
|
5
|
Zhang Q, Fan X, Fu F, Zhu Y, Luo G, Chen H. Adar Regulates Drosophila melanogaster Spermatogenesis via Modulation of BMP Signaling. Int J Mol Sci 2024; 25:5643. [PMID: 38891830 PMCID: PMC11171878 DOI: 10.3390/ijms25115643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/16/2024] [Accepted: 05/20/2024] [Indexed: 06/21/2024] Open
Abstract
The dynamic process of Drosophila spermatogenesis involves asymmetric division, mitosis, and meiosis, which ultimately results in the production of mature spermatozoa. Disorders of spermatogenesis can lead to infertility in males. ADAR (adenosine deaminase acting on RNA) mutations in Drosophila cause male infertility, yet the causative factors remain unclear. In this study, immunofluorescence staining was employed to visualize endogenous ADAR proteins and assess protein levels via fluorescence-intensity analysis. In addition, the early differentiation disorders and homeostatic alterations during early spermatogenesis in the testes were examined through quantification of transit-amplifying region length, counting the number of GSCs (germline stem cells), and fertility experiments. Our findings suggest that deletion of ADAR causes testicular tip transit-amplifying cells to accumulate and become infertile in older male Drosophila. By overexpressing ADAR in early germline cells, male infertility can be partially rescued. Transcriptome analysis showed that ADAR maintained early spermatogenesis homeostasis through the bone-morphogenetic-protein (BMP) signaling pathway. Taken together, these findings have the potential to help explore the role of ADAR in early spermatogenesis.
Collapse
Affiliation(s)
- Qian Zhang
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Laboratory of Stem Cell and Aging Research, Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Respiratory Health and Multimorbidity and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xinxin Fan
- Laboratory of Stem Cell and Aging Research, Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Respiratory Health and Multimorbidity and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Fang Fu
- Laboratory of Stem Cell and Aging Research, Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Respiratory Health and Multimorbidity and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yuedan Zhu
- Laboratory of Stem Cell and Aging Research, Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Respiratory Health and Multimorbidity and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Guanzheng Luo
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Haiyang Chen
- Laboratory of Stem Cell and Aging Research, Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Respiratory Health and Multimorbidity and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China
| |
Collapse
|
6
|
Tao X, Dou Y, Huang G, Sun M, Lu S, Chen D. α-Tubulin Regulates the Fate of Germline Stem Cells in Drosophila Testis. Sci Rep 2021; 11:10644. [PMID: 34017013 PMCID: PMC8138004 DOI: 10.1038/s41598-021-90116-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 05/04/2021] [Indexed: 12/02/2022] Open
Abstract
The Drosophila testis provides an exemplary model for analyzing the extrinsic and intrinsic factors that regulate the fate of stem cell in vivo. Using this model, we show that the Drosophila αTub67C gene (full name αTubulin at 67C), which encodes α4-Tubulin (a type of α-Tubulin), plays a new role in controlling the fate of male germline stem cells (GSC). In this study, we have found that Drosophila α4-Tubulin is required intrinsically and extrinsically for GSCs maintenance. Results from green fluorescent protein (GFP)-transgene reporter assays show that the gene αTub67C is not required for Dpp/Gbb signaling silencing of bam expression, suggesting that αTub67C functions downstream of or parallel to bam, and is independent of Gbb/Dpp-bam signaling pathway. Furthermore, overexpression of αTub67C fails to obviously increase the number of GSC/Gonialblast (GB). Given that the α-tubulin genes are evolutionarily conserved from yeast to human, which triggers us to study the more roles of the gene α-tubulin in other animals in the future.
Collapse
Affiliation(s)
- Xiaoqian Tao
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Yunqiao Dou
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China.,Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Guangyu Huang
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China.,Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Mingzhong Sun
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Shan Lu
- Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
| | - Dongsheng Chen
- Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological Resources, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China. .,Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, 241000, China. .,College of Life Sciences, The Institute of Bioinformatics, Anhui Normal University, Wuhu, 241000, China.
| |
Collapse
|
7
|
Greenspan LJ, Matunis EL. Retinoblastoma Intrinsically Regulates Niche Cell Quiescence, Identity, and Niche Number in the Adult Drosophila Testis. Cell Rep 2019; 24:3466-3476.e8. [PMID: 30257208 PMCID: PMC6226258 DOI: 10.1016/j.celrep.2018.08.083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/29/2018] [Accepted: 08/27/2018] [Indexed: 12/20/2022] Open
Abstract
Homeostasis in adult tissues depends on the precise regulation of stem cells and their surrounding microenvironments, or niches. Here, we show that the cell cycle inhibitor and tumor suppressor Retinoblastoma (RB) is a critical regulator of niche cells in the Drosophila testis. The testis contains a single niche, composed of somatic hub cells, that signals to adjacent germline and somatic stem cells. Hub cells are normally quiescent, but knockdown of the RB homolog Rbf in these cells causes them to proliferate and convert to somatic stem cells. Over time, mutant hub cell clusters enlarge and split apart, forming ectopic hubs surrounded by active stem cells. Furthermore, we show that Rbf’s ability to restrict niche number depends on the transcription factors E2F and Escargot and the adhesion molecule E-cadherin. Together this work reveals how precise modulation of niche cells, not only the stem cells they support, can drive regeneration and disease. Greenspan and Matunis find that the tumor suppressor Retinoblastoma is required in niche cells to maintain quiescence, cell fate, and niche number. Loss of Retinoblastoma causes niche cell divisions, conversion to somatic stem cells, and ectopic niche formation through niche fission, suggesting that mutations in niche cells may drive disease.
Collapse
Affiliation(s)
- Leah J Greenspan
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Erika L Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
8
|
Lu Y, Yao Y, Li Z. Ectopic Dpp signaling promotes stem cell competition through EGFR signaling in the Drosophila testis. Sci Rep 2019; 9:6118. [PMID: 30992503 PMCID: PMC6467874 DOI: 10.1038/s41598-019-42630-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 04/02/2019] [Indexed: 12/28/2022] Open
Abstract
Stem cell competition could select the fittest stem cells and potentially control tumorigenesis. However, little is known about the underlying molecular mechanisms. Here, we find that ectopic Decapentaplegic (Dpp) signal activation by expressing a constitutively active form of Thickveins (TkvCA) in cyst stem cells (CySCs) leads to competition between CySCs and germline stem cells (GSCs) for niche occupancy and GSC loss. GSCs are displaced from the niche and undergo differentiation. Interestingly, we find that induction of TkvCA results in elevated expression of vein, which further activates Epidermal Growth Factor Receptor (EGFR) signaling in CySCs to promote their proliferation and compete GSCs out of the niche. Our findings elucidate the important role of Dpp signaling in regulating stem cell competition and tumorigenesis, which could be shed light on tumorigenesis and cancer treatment in mammals.
Collapse
Affiliation(s)
- Yanfen Lu
- College of Plant Science and Technology, Beijing University of Agriculture, No. 7 Beinong Road, Changping District, Beijing, 102206, China
| | - Yuncong Yao
- College of Plant Science and Technology, Beijing University of Agriculture, No. 7 Beinong Road, Changping District, Beijing, 102206, China.
| | - Zhouhua Li
- College of Life Sciences, Capital Normal University, Beijing, 100048, China.
| |
Collapse
|
9
|
|
10
|
Xu R, Li J, Zhao H, Kong R, Wei M, Shi L, Bai G, Li Z. Self-restrained regulation of stem cell niche activity by niche components in the Drosophila testis. Dev Biol 2018; 439:42-51. [PMID: 29679558 DOI: 10.1016/j.ydbio.2018.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/15/2018] [Accepted: 04/15/2018] [Indexed: 12/12/2022]
Abstract
Most, if not all, stem cells reside in a defined microenvironment, called the niche. Short-ranged niche signal must be tightly controlled to be active only inside the niche to maintain the proper balance of stem cell self-renewal verse differentiation. However, how niche components restrict localized niche signal activation remains largely unknown. Here, we find that Thickveins (Tkv, a type I receptor of the Dpp signaling pathway) in cyst stem cells (CySCs) of the testis niche prevents Dpp signaling activation outside of the niche. We show that Tkv functions as Dpp trap/sink to spatially restrain Dpp signaling inside the niche. This self-restrained regulation of niche activity by Tkv in CySCs is independent of the canonical Dpp signaling pathway. Our data demonstrate the critical roles of niche components (CySCs) in the self-restrained regulation of niche activity, which could be shed light on niche activity regulation in general.
Collapse
Affiliation(s)
- Ran Xu
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Jing Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Hang Zhao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ruiyan Kong
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Min Wei
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Lin Shi
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Guang Bai
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Zhouhua Li
- College of Life Sciences, Capital Normal University, Beijing 100048, China.
| |
Collapse
|
11
|
Abstract
The extracellular matrix (ECM) has central roles in tissue integrity and remodeling throughout the life span of animals. While collagens are the most abundant structural components of ECM in most tissues, tissue-specific molecular complexity is contributed by ECM glycoproteins. The matricellular glycoproteins are categorized primarily according to functional criteria and represented predominantly by the thrombospondin, tenascin, SPARC/osteonectin, and CCN families. These proteins do not self-assemble into ECM fibrils; nevertheless, they shape ECM properties through interactions with structural ECM proteins, growth factors, and cells. Matricellular proteins also promote cell migration or morphological changes through adhesion-modulating or counter-adhesive actions on cell-ECM adhesions, intracellular signaling, and the actin cytoskeleton. Typically, matricellular proteins are most highly expressed during embryonic development. In adult tissues, expression is more limited unless activated by cues for dynamic tissue remodeling and cell motility, such as occur during inflammatory response and wound repair. Many insights in the complex roles of matricellular proteins have been obtained from studies of gene knockout mice. However, with the exception of chordate-specific tenascins, these are highly conserved proteins that are encoded in many animal phyla. This review will consider the increasing body of research on matricellular proteins in nonmammalian animal models. These models provide better access to the very earliest stages of embryonic development and opportunities to study biological processes such as limb and organ regeneration. In aggregate, this research is expanding concepts of the functions and mechanisms of action of matricellular proteins.
Collapse
Affiliation(s)
- Josephine C Adams
- School of Biochemistry, University of Bristol, Bristol, United Kingdom.
| |
Collapse
|
12
|
Inaba M, Yamashita YM, Buszczak M. Keeping stem cells under control: New insights into the mechanisms that limit niche-stem cell signaling within the reproductive system. Mol Reprod Dev 2018; 83:675-83. [PMID: 27434704 DOI: 10.1002/mrd.22682] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/12/2016] [Indexed: 12/12/2022]
Abstract
Adult stem cells reside in specialized microenvironments, called niches, that maintain stem cells in an undifferentiated and self-renewing state. Defining and understanding the mechanisms that restrict niche signaling exclusively to stem cells is crucial to determine how stem cells undergo self-renewal while their progeny, often located just one cell diameter away from the niche, differentiate. Despite extensive studies on the signaling pathways that operate within stem cells and their niches, how this segregation occurs remains elusive. Here we review recent progress on the characterization of niche-stem cell interactions, with a focus on emerging mechanisms that spatially restrict niche signaling. Mol. Reprod. Dev. 83: 675-683, 2016 © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Mayu Inaba
- Department of Cell and Developmental Biology Medical School, Life Sciences Institute, University of Michigan, Ann Arbor, Michigan.,Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan.,Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Yukiko M Yamashita
- Department of Cell and Developmental Biology Medical School, Life Sciences Institute, University of Michigan, Ann Arbor, Michigan.,Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas
| |
Collapse
|
13
|
Bactrocera dorsalis male sterilization by targeted RNA interference of spermatogenesis: empowering sterile insect technique programs. Sci Rep 2016; 6:35750. [PMID: 27767174 PMCID: PMC5073305 DOI: 10.1038/srep35750] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 09/30/2016] [Indexed: 11/08/2022] Open
Abstract
RNA interference (RNAi) is a genetic technique which has novel application for sustainable pest control. The Sterile Insect Technique (SIT) uses releases of mass-produced, sterile male insects to out-compete wild males for mates to reduce pest populations. RNAi sterilization of SIT males would have several advantages over radiation sterilization, but to achieve this appropriate target genes must first be identified and then targeted with interference technology. With this goal, eight spermatogenesis related candidate genes were cloned and tested for potential activity in Bactrocera dorsalis. The knockdown of candidate genes by oral delivery of dsRNAs did not influence the mating of male flies, but significantly affected the daily average number of eggs laid by females, and reduced egg hatching rate by 16-60%. RNAi negatively affected spermatozoa quantitatively and qualitatively. Following the mating of lola-/topi-/rac-/rho-/upd-/magu-silenced males, we recorded a significant decrease in number and length of spermatozoa in female spermatheca compared to gfp-silenced control group. In a greenhouse trial, the number of damaged oranges and B. dorsalis larvae were significantly reduced in a dsrho-treated group compared with the dsgfp group. This study provides strong evidence for the use RNAi in pest management, especially for the improvement of SIT against B. dorsalis and other species.
Collapse
|
14
|
The ins(ide) and outs(ide) of asymmetric stem cell division. Curr Opin Cell Biol 2016; 43:1-6. [PMID: 27318429 DOI: 10.1016/j.ceb.2016.06.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 05/26/2016] [Accepted: 06/04/2016] [Indexed: 01/12/2023]
Abstract
Many adult stem cells divide asymmetrically, generating one stem cell (self-renewal) and one differentiating cell. Balancing self-renewal and differentiation is critical for sustaining tissue homeostasis throughout the life of an organism. Failure to execute asymmetric stem cell division can have profound impacts on tissue homeostasis, resulting in tissue degeneration or hyperplasia/tumorigenic overgrowth. Recent studies have expanded our understanding of both the extracellular and intracellular mechanisms that regulate, reinforce and ensure an asymmetric outcome following stem cell division. In this review, we discuss newly discovered aspects of asymmetric stem cell division that, in concert with well-established mechanisms, contribute to balancing self-renewal and differentiation.
Collapse
|
15
|
Norman M, Vuilleumier R, Springhorn A, Gawlik J, Pyrowolakis G. Pentagone internalises glypicans to fine-tune multiple signalling pathways. eLife 2016; 5. [PMID: 27269283 PMCID: PMC4924993 DOI: 10.7554/elife.13301] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 06/07/2016] [Indexed: 12/14/2022] Open
Abstract
Tight regulation of signalling activity is crucial for proper tissue patterning and growth. Here we investigate the function of Pentagone (Pent), a secreted protein that acts in a regulatory feedback during establishment and maintenance of BMP/Dpp morphogen signalling during Drosophila wing development. We show that Pent internalises the Dpp co-receptors, the glypicans Dally and Dally-like protein (Dlp), and propose that this internalisation is important in the establishment of a long range Dpp gradient. Pent-induced endocytosis and degradation of glypicans requires dynamin- and Rab5, but not clathrin or active BMP signalling. Thus, Pent modifies the ability of cells to trap and transduce BMP by fine-tuning the levels of the BMP reception system at the plasma membrane. In addition, and in accordance with the role of glypicans in multiple signalling pathways, we establish a requirement of Pent for Wg signalling. Our data propose a novel mechanism by which morphogen signalling is regulated.
Collapse
Affiliation(s)
- Mark Norman
- Centre for Biological Signalling Studies, Albert-Ludwigs-University of Freiburg, Breisgau, Germany
| | - Robin Vuilleumier
- Institute for Biology I, Albert-Ludwigs-University of Freiburg, Breisgau, Germany
| | - Alexander Springhorn
- Institute for Biology I, Albert-Ludwigs-University of Freiburg, Breisgau, Germany.,Spemann Graduate School of Biology and Medicine, Albert-Ludwigs-University of Freiburg, Breisgau, Germany
| | - Jennifer Gawlik
- Centre for Biological Signalling Studies, Albert-Ludwigs-University of Freiburg, Breisgau, Germany.,Spemann Graduate School of Biology and Medicine, Albert-Ludwigs-University of Freiburg, Breisgau, Germany
| | - George Pyrowolakis
- Centre for Biological Signalling Studies, Albert-Ludwigs-University of Freiburg, Breisgau, Germany.,Institute for Biology I, Albert-Ludwigs-University of Freiburg, Breisgau, Germany
| |
Collapse
|
16
|
Lee JY, Chen JY, Shaw JL, Chang KT. Maintenance of Stem Cell Niche Integrity by a Novel Activator of Integrin Signaling. PLoS Genet 2016; 12:e1006043. [PMID: 27191715 PMCID: PMC4871447 DOI: 10.1371/journal.pgen.1006043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 04/19/2016] [Indexed: 01/22/2023] Open
Abstract
Stem cells depend critically on the surrounding microenvironment, or niche, for their maintenance and self-renewal. While much is known about how the niche regulates stem cell self-renewal and differentiation, mechanisms for how the niche is maintained over time are not well understood. At the apical tip of the Drosophila testes, germline stem cells (GSCs) and somatic stem cells share a common niche formed by hub cells. Here we demonstrate that a novel protein named Shriveled (Shv) is necessary for the maintenance of hub/niche integrity. Depletion of Shv protein results in age-dependent deterioration of the hub structure and loss of GSCs, whereas upregulation of Shv preserves the niche during aging. We find Shv is a secreted protein that modulates DE-cadherin levels through extracellular activation of integrin signaling. Our work identifies Shv as a novel activator of integrin signaling and suggests a new integration model in which crosstalk between integrin and DE-cadherin in niche cells promote their own preservation by maintaining the niche architecture. Stem cells are vital for development and for regeneration and repair of tissues in an organism. The ability of adult stem cells to maintain their “stemness” depends critically on the localized microenvironment, or niche. While much is known about how the niche regulates stem cell self-renewal and differentiation, mechanisms for how the niche is maintained during aging are not well understood. Using Drosophila testis as a model system, here we demonstrate that a protein we named Shriveled is a secreted protein that activates integrin signaling to preserve niche architecture. We also show that Shriveled-dependent activation of integrin maintains normal E-cadherin levels in the niche cells, providing a mechanism for niche maintenance. Interestingly, upregulation of Shriveled retards the loss of niche and stem cells seen during normal aging. Together, our work identifies Shriveled as a novel molecule required for preservation of the niche structure in the Drosophila testis.
Collapse
Affiliation(s)
- Joo Yeun Lee
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| | - Jessica Y. Chen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jillian L. Shaw
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| | - Karen T. Chang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
17
|
Basic mechanisms of longevity: A case study of Drosophila pro-longevity genes. Ageing Res Rev 2015; 24:218-31. [PMID: 26318059 DOI: 10.1016/j.arr.2015.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/11/2015] [Accepted: 08/20/2015] [Indexed: 12/13/2022]
Abstract
Drosophila is one of the most convenient model organisms in the genetics of aging and longevity. Unlike the nematodes, which allow for the detection of new pro-aging genes by knockout and RNAi-mediated knock-down, Drosophila also provides an opportunity to find new pro-longevity genes by driver-induced overexpression. Similar studies on other models are extremely rare. In this review, we focused on genes whose overexpression prolongs the life of fruit flies. The majority of longevity-associated genes regulates metabolism and stress resistance, and belongs to the IGF-1R, PI3K, PKB, AMPK and TOR metabolic regulation cluster and the FOXO, HDAC, p53 stress response cluster.
Collapse
|
18
|
Miller PB, Obrik-Uloho OT, Phan MH, Medrano CL, Renier JS, Thayer JL, Wiessner G, Bloch Qazi MC. The song of the old mother: reproductive senescence in female drosophila. Fly (Austin) 2015; 8:127-39. [PMID: 25523082 DOI: 10.4161/19336934.2014.969144] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Among animals with multiple reproductive episodes, changes in adult condition over time can have profound effects on lifetime reproductive fitness and offspring performance. The changes in condition associated with senescence can be particularly acute for females who support reproductive processes from oogenesis through fertilization. The pomace fly Drosophila melanogaster is a well-established model system for exploring the physiology of reproduction and senescence. In this review, we describe how increasing maternal age in Drosophila affects reproductive fitness and offspring performance as well as the genetic foundation of these effects. Describing the processes underlying female reproductive senescence helps us understand diverse phenomena including population demographics, condition-dependent selection, sexual conflict, and transgenerational effects of maternal condition on offspring fitness. Understanding the genetic basis of reproductive senescence clarifies the nature of life-history trade-offs as well as potential ways to augment and/or limit female fertility in a variety of organisms.
Collapse
Affiliation(s)
- Paige B Miller
- a Department of Biology ; Gustavus Adolphus College ; St Peter , MN USA
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Dorn DC, Dorn A. Stem cell autotomy and niche interaction in different systems. World J Stem Cells 2015; 7:922-944. [PMID: 26240680 PMCID: PMC4515436 DOI: 10.4252/wjsc.v7.i6.922] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 05/27/2015] [Indexed: 02/06/2023] Open
Abstract
The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon pruning and dying-back degeneration in neurodegenerative diseases. Especially the hypothesis of an existing evolutionary conserved “autodestruction program” in axons that might also be active in GSC projections appears attractive. Investigations on the underlying signaling pathways have to be carried out. There are two other well known cases of programmed cell autotomy: the enucleation of erythroblasts in the process of erythrocyte maturation and the segregation of thousands of thrombocytes (platelets) from one megakaryocyte. Both progenitor cell types - erythroblasts and megakaryocytes - are associated with a niche in the bone marrow, erythroblasts with a macrophage, which they surround, and the megakaryocytes with the endothelial cells of sinusoids and their extracellular matrix. Although the regulatory mechanisms may be specific in each case, there is one aspect that connects all described processes of programmed cell autotomy and neuronal autodestruction: apoptotic pathways play always a prominent role. Studies on the role of male GSC autotomy in stem cell-niche interaction have just started but are expected to reveal hitherto unknown ways of signal exchange. Spermatogenesis in mammals advance our understanding of insect spermatogenesis. Mammal and insect spermatogenesis share some broad principles, but a comparison of the signaling pathways is difficult. We have intimate knowledge from Drosophila, but of almost no other insect, and we have only limited knowledge from mammals. The discovery of stem cell autotomy as part of the interaction with the niche promises new general insights into the complicated stem cell-niche interdependence.
Collapse
|
20
|
|
21
|
Lim C, Tarayrah L, Chen X. Transcriptional regulation during Drosophila spermatogenesis. SPERMATOGENESIS 2014; 2:158-166. [PMID: 23087835 PMCID: PMC3469439 DOI: 10.4161/spmg.21775] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Drosophila spermatogenesis has become a paradigmatic system for the study of mechanisms that regulate adult stem cell maintenance, proliferation and differentiation. The dramatic cellular differentiation process from germline stem cell (GSC) to mature sperm is accompanied by dynamic changes in gene expression, which are regulated at transcriptional, post-transcriptional (including translational) and post-translational levels. Post-transcriptional regulation has been proposed as a unique feature of germ cells. However, recent studies have provided new insights into transcriptional regulation during Drosophila spermatogenesis. Both signaling pathways and epigenetic mechanisms act to orchestrate the transcriptional regulation of distinct genes at different germ cell differentiation stages. Many of the regulatory pathways that control male gamete differentiation in Drosophila are conserved in mammals. Therefore, studies using Drosophila spermatogenesis will provide insight into the molecular mechanisms that regulate mammalian germ cell differentiation pathways.
Collapse
Affiliation(s)
- Cindy Lim
- Department of Biology; The Johns Hopkins University; Baltimore, MD USA
| | | | | |
Collapse
|
22
|
Amoyel M, Bach EA. Functions of the Drosophila JAK-STAT pathway: Lessons from stem cells. JAKSTAT 2014; 1:176-83. [PMID: 24058767 PMCID: PMC3670241 DOI: 10.4161/jkst.21621] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/13/2012] [Accepted: 07/25/2012] [Indexed: 01/06/2023] Open
Abstract
JAK-STAT signaling has been proposed to act in numerous stem cells in a variety of organisms. Here we provide an overview of its roles in three well characterized stem cell populations in Drosophila, in the intestine, lymph gland and testis. In flies, there is a single JAK and a single STAT, which has made the genetic dissection of pathway function considerably easier and facilitated the analysis of communication between stem cells, their niches and offspring. Studies in flies have revealed roles for this pathway as diverse as regulating bona fide intrinsic self-renewal, integrating response to environmental cues that control quiescence and promoting mitogenic responses to stress.
Collapse
Affiliation(s)
- Marc Amoyel
- Department of Biochemistry and Molecular Pharmacology; New York University School of Medicine; New York, NY USA
| | | |
Collapse
|
23
|
Hamaratoglu F, Affolter M, Pyrowolakis G. Dpp/BMP signaling in flies: from molecules to biology. Semin Cell Dev Biol 2014; 32:128-36. [PMID: 24813173 DOI: 10.1016/j.semcdb.2014.04.036] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 04/30/2014] [Indexed: 01/08/2023]
Abstract
Decapentaplegic (Dpp), the fly homolog of the secreted mammalian BMP2/4 signaling molecules, is involved in almost all aspects of fly development. Dpp has critical functions at all developmental stages, from patterning of the eggshell to the determination of adult intestinal stem cell identity. Here, we focus on recent findings regarding the transcriptional regulatory logic of the pathway, on a new feedback regulator, Pentagone, and on Dpp's roles in scaling and growth of the Drosophila wing.
Collapse
Affiliation(s)
- Fisun Hamaratoglu
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.
| | - Markus Affolter
- Growth & Development, Biozentrum, University of Basel, Basel, Switzerland
| | - George Pyrowolakis
- Institute for Biology I, Albert-Ludwigs-University of Freiburg, Freiburg, Germany; Centre for Biological Signaling Studies (BIOSS), Albert-Ludwigs-University of Freiburg, Freiburg, Germany
| |
Collapse
|
24
|
Voog J, Sandall SL, Hime GR, Resende LPF, Loza-Coll M, Aslanian A, Yates JR, Hunter T, Fuller MT, Jones DL. Escargot restricts niche cell to stem cell conversion in the Drosophila testis. Cell Rep 2014; 7:722-34. [PMID: 24794442 DOI: 10.1016/j.celrep.2014.04.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 02/05/2013] [Accepted: 04/17/2014] [Indexed: 01/08/2023] Open
Abstract
Stem cells reside within specialized microenvironments, or niches, that control many aspects of stem cell behavior. Somatic hub cells in the Drosophila testis regulate the behavior of cyst stem cells (CySCs) and germline stem cells (GSCs) and are a primary component of the testis stem cell niche. The shutoff (shof) mutation, characterized by premature loss of GSCs and CySCs, was mapped to a locus encoding the evolutionarily conserved transcription factor Escargot (Esg). Hub cells depleted of Esg acquire CySC characteristics and differentiate as cyst cells, resulting in complete loss of hub cells and eventually CySCs and GSCs, similar to the shof mutant phenotype. We identified Esg-interacting proteins and demonstrate an interaction between Esg and the corepressor C-terminal binding protein (CtBP), which was also required for maintenance of hub cell fate. Our results indicate that niche cells can acquire stem cell properties upon removal of a single transcription factor in vivo.
Collapse
Affiliation(s)
- Justin Voog
- Department of Biomedical Sciences, University of California, San Diego, La Jolla, CA, 92037, USA; Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sharsti L Sandall
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Gary R Hime
- ARC Centre of Excellence in Biotechnology and Development, University of Melbourne, VIC 3010, Australia; Department of Anatomy and Neuroscience, University of Melbourne, VIC 3010, Australia
| | - Luís Pedro F Resende
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; GABBA, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Portugal
| | - Mariano Loza-Coll
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Aaron Aslanian
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Margaret T Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - D Leanne Jones
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| |
Collapse
|
25
|
Bausek N. JAK-STAT signaling in stem cells and their niches in Drosophila. JAKSTAT 2013; 2:e25686. [PMID: 24069566 PMCID: PMC3772118 DOI: 10.4161/jkst.25686] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/09/2013] [Accepted: 07/09/2013] [Indexed: 12/30/2022] Open
Abstract
JAK-STAT signaling is a highly conserved regulator of stem cells and their niches. Aberrant activation in hematopoietic stem cells is the underlying cause of a majority of myeloproliferative diseases. This review will focus on the roles of JAK-STAT activity in three different adult stem cell systems in Drosophila. Tightly controlled levels of JAK-STAT signaling are required for stem cell maintenance and self-renewal, as hyperactivation of the pathway is associated with stem cell overproliferation. JAK-STAT activity is further essential for anchoring the stem cells in their respective niches by regulating different adhesion molecules.
Collapse
Affiliation(s)
- Nina Bausek
- MRC Centre for Development and Biomedical Genetics and The Department of Biomedical Science; The University of Sheffield; Sheffield, UK
| |
Collapse
|
26
|
Resende LPF, Boyle M, Tran D, Fellner T, Jones DL. Headcase promotes cell survival and niche maintenance in the Drosophila testis. PLoS One 2013; 8:e68026. [PMID: 23874487 PMCID: PMC3706621 DOI: 10.1371/journal.pone.0068026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 05/24/2013] [Indexed: 11/19/2022] Open
Abstract
At the apical tip of the Drosophila testis, germline and somatic stem cells surround a cluster of somatic cells called the hub. Hub cells produce a self-renewal factor, Unpaired (Upd), that activates the JAK-STAT pathway in adjacent stem cells to regulate stem cell behavior. Therefore, apical hub cells are a critical component of the stem cell niche in the testis. In the course of a screen to identify factors involved in regulating hub maintenance, we identified headcase (hdc). Hub cells depleted for hdc undergo programmed cell death, suggesting that anti-apoptotic pathways play an important role in maintenance of the niche. Using hdc as paradigm, we describe here the first comprehensive analysis on the effects of a progressive niche reduction on the testis stem cell pool. Surprisingly, single hub cells remain capable of supporting numerous stem cells, indicating that although the size and number of niche support cells influence stem cell maintenance, the testis stem cell niche appears to be remarkably robust in the its ability to support stem cells after severe damage.
Collapse
Affiliation(s)
- Luís Pedro F. Resende
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
- Graduate Program in Areas of Basic and Applied Biology, Instituto Ciências Biomédicas Abel Salazar, University Porto, Porto, Portugal
| | - Monica Boyle
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Darrell Tran
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Thomas Fellner
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - D. Leanne Jones
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
- Molecular, Cell, and Developmental Biology, University of California-Los Angeles, Los Angeles, California, United States of America
- * E-mail:
| |
Collapse
|
27
|
Abstract
Asymmetric cell division (ACD) produces two daughter cells with distinct fates or characteristics. Many adult stem cells use ACD as a means of maintaining stem cell number and thus tissue homeostasis. Here, we review recent progress on ACD, discussing conservation between stem and non-stem cell systems, molecular mechanisms, and the biological meaning of ACD.
Collapse
|
28
|
Dual roles of Hh signaling in the regulation of somatic stem cell self-renewal and germline stem cell maintenance in Drosophila testis. Cell Res 2013; 23:573-6. [PMID: 23419515 DOI: 10.1038/cr.2013.29] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
|
29
|
Singh SR, Liu Y, Kango-Singh M, Nevo E. Genetic, immunofluorescence labeling, and in situ hybridization techniques in identification of stem cells in male and female germline niches. Methods Mol Biol 2013; 1035:9-23. [PMID: 23959978 DOI: 10.1007/978-1-62703-508-8_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stem cells have an enormous capacity of self-renewal, as well as the ability to differentiate into specialized cell types. Proper control of these two properties of stem cells is crucial for animal development, growth control, and reproduction. Germline stem cells (GSCs) are a self-renewing population of germ cells, which generate haploid gametes (sperms or oocyte) that transmit genetic information from generation to generation. In Drosophila testis and ovary, GSCs are anchored around the niche cells. The cap cells cluster in females and hub cells in males act as a niche to control GSC behavior. With highly sophisticated genetic techniques in Drosophila, tremendous progress has been made in understanding the interactions between stem cells and niches at cellular and molecular levels. Here, we provide details of genetic, immunofluorescence labeling, and in situ hybridization techniques in identification and characterization of stem cells in Drosophila male and female germline niches.
Collapse
Affiliation(s)
- Shree Ram Singh
- Mouse Cancer Genetics Program, National Cancer Institute, NIH, Frederick, MD, USA
| | | | | | | |
Collapse
|
30
|
Sinden D, Badgett M, Fry J, Jones T, Palmen R, Sheng X, Simmons A, Matunis E, Wawersik M. Jak-STAT regulation of cyst stem cell development in the Drosophila testis. Dev Biol 2012; 372:5-16. [PMID: 23010510 DOI: 10.1016/j.ydbio.2012.09.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/15/2012] [Accepted: 09/16/2012] [Indexed: 10/27/2022]
Abstract
Establishment and maintenance of functional stem cells is critical for organ development and tissue homeostasis. Little is known about the mechanisms underlying stem establishment during organogenesis. Drosophila testes are among the most thoroughly characterized systems for studying stem cell behavior, with germline stem cells (GSCs) and somatic cyst stem cells (CySCs) cohabiting a discrete stem cell niche at the testis apex. GSCs and CySCs are arrayed around hub cells that also comprise the niche and communication between hub cells, GSCs, and CySCs regulates the balance between stem cell maintenance and differentiation. Recent data has shown that functional, asymmetrically dividing GSCs are first established at ∼23 h after egg laying during Drosophila testis morphogenesis (Sheng et al., 2009). This process correlates with coalescence of the hub, but development of CySCs from somatic gonadal precursors (SGPs) was not examined. Here, we show that functional CySCs are present at the time of GSC establishment, and that Jak-STAT signaling is necessary and sufficient for CySC maintenance shortly thereafter. Furthermore, hyper-activation of Jak in CySCs promotes expansion of the GSC population, while ectopic Jak activation in the germline induces GSC gene expression in GSC daughter cells but does not prevent spermatogenic differentiation. Together, these observations indicate that, similar to adult testes, Jak-STAT signaling from the hub acts on both GSCs and CySC to regulate their development and differentiation, and that additional signaling from CySCs to the GSCs play a dominant role in controlling GSC maintenance during niche formation.
Collapse
Affiliation(s)
- D Sinden
- College of William & Mary, Biology Department, Williamsburg, VA 23185, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Matunis EL, Stine RR, de Cuevas M. Recent advances in Drosophila male germline stem cell biology. SPERMATOGENESIS 2012; 2:137-144. [PMID: 23087833 PMCID: PMC3469437 DOI: 10.4161/spmg.21763] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The ability of stem cells to divide asymmetrically to produce both self-renewing and differentiating daughter cells sustains many adult tissues, but germline stem cells (GSCs) are unique among stem cells as they perpetuate the genome of the species. The cellular and molecular mechanisms regulating most mammalian stem cells in their endogenous local microenvironments, or niches, are quite challenging to study. However, studies of stem cell niches such as those found in the Drosophila gonads have proven very useful. In these tissues, GSCs are housed in a readily identifiable niche, and the ability to genetically manipulate these cells and their neighbors has uncovered several fundamental mechanisms that are relevant to stem cells more generally. Here, we summarize recent work on the regulation of GSCs in the Drosophila testis niche by intercellular signals, and on the intracellular mechanisms that cooperate with these signals to ensure the survival of the germline. This review focuses on GSCs within the adult Drosophila testis; somatic stem cells in this tissue are reviewed by Zoller and Schulz in this issue.(1) For a review of the testis niche as a whole, see de Cuevas and Matunis,(2) and for more comprehensive reviews of the Drosophila testis, refer to Fuller(3) and Davies and Fuller.(4).
Collapse
Affiliation(s)
- Erika L. Matunis
- Department of Cell Biology; Johns Hopkins University School of Medicine; Baltimore, MD USA
| | - Rachel R. Stine
- Department of Cell Biology; Johns Hopkins University School of Medicine; Baltimore, MD USA
| | - Margaret de Cuevas
- Department of Cell Biology; Johns Hopkins University School of Medicine; Baltimore, MD USA
| |
Collapse
|
32
|
Papagiannouli F, Lohmann I. Shaping the niche: lessons from the Drosophila testis and other model systems. Biotechnol J 2012; 7:723-36. [PMID: 22488937 DOI: 10.1002/biot.201100352] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 01/31/2012] [Accepted: 02/27/2012] [Indexed: 11/12/2022]
Abstract
Stem cells are fascinating, as they supply the cells that construct our adult bodies and replenish, as we age, worn out, damaged, and diseased tissues. Stem cell regulation relies on intrinsic signals but also on inputs emanating from the neighbouring niche. The Drosophila testis provides an excellent system for studying such processes. Although recent advances have uncovered several signalling, cytoskeletal and other factors affecting niche homeostasis and testis differentiation, many aspects of niche regulation and maintenance remain unsolved. In this review, we discuss aspects of niche establishment and integrity not yet fully understood and we compare it to the current knowledge in other model systems such as vertebrates and plants. We also address specific questions on stem cell maintenance and niche regulation in the Drosophila testis under the control of Hox genes. Finally, we provide insights on the striking functional conservation of homologous genes in plants and animals and their respective stem cell niches. Elucidating conserved mechanisms of stem cell control in both lineages could reveal the importance underlying this conservation and justify the evolutionary pressure to adapt homologous molecules for performing the same task.
Collapse
Affiliation(s)
- Fani Papagiannouli
- Centre for Organismal Studies (COS) Heidelberg and CellNetworks - Cluster of Excellence, Heidelberg, Germany.
| | | |
Collapse
|
33
|
Local signaling within stem cell niches: insights from Drosophila. Curr Opin Cell Biol 2012; 24:225-31. [PMID: 22296770 DOI: 10.1016/j.ceb.2012.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/05/2012] [Accepted: 01/11/2012] [Indexed: 11/24/2022]
Abstract
Tissue stem cells are found in specialized microenvironments (niches) where they are exposed to diverse systemic and local signals that are integrated with cell intrinsic factors to regulate stem cell behavior. In general, systemic signals are utilized to coordinate the response of tissues to acute or long-term changes that affect the whole organism, such as variations in nutrient availability or aging. In contrast, local signaling regulates tissue maintenance by balancing stem cell self-renewal with differentiation under homeostatic conditions and in response to local damage. In this review, we highlight the role of the JAK-STAT pathway in two Drosophila stem cell systems, the testis and intestine, and compare and contrast how activation of this pathway leads to tissue maintenance under both homeostatic conditions and in response to stress or injury.
Collapse
|
34
|
Bradshaw AD. Diverse biological functions of the SPARC family of proteins. Int J Biochem Cell Biol 2012; 44:480-8. [PMID: 22249026 DOI: 10.1016/j.biocel.2011.12.021] [Citation(s) in RCA: 202] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 12/09/2011] [Accepted: 12/27/2011] [Indexed: 12/14/2022]
Abstract
The SPARC family of proteins represents a diverse group of proteins that modulate cell interaction with the extracellular milieu. The eight members of the SPARC protein family are modular in nature. Each shares a follistatin-like domain and an extracellular calcium binding E-F hand motif. In addition, each family member is secreted into the extracellular space. Some of the shared activities of this family include, regulation of extracellular matrix assembly and deposition, counter-adhesion, effects on extracellular protease activity, and modulation of growth factor/cytokine signaling pathways. Recently, several SPARC family members have been implicated in human disease pathogenesis. This review discusses recent advances in the understanding of the functional roles of the SPARC family of proteins in development and disease.
Collapse
Affiliation(s)
- Amy D Bradshaw
- Division of Cardiology, Department of Medicine, Medical University of South Carolina and Ralph H. Johnson Veteran's Administration, Charleston, SC, United States.
| |
Collapse
|