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Chen X, Qi Y, Huang Q, Sun C, Zheng Y, Ji L, Shi Y, Cheng X, Li Z, Zheng S, Cao Y, Gu Z, Yu J. Single-cell transcriptome characteristics of testicular terminal epithelium lineages during aging in the Drosophila. Aging Cell 2024; 23:e14057. [PMID: 38044573 DOI: 10.1111/acel.14057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 12/05/2023] Open
Abstract
Aging is a complex biological process leading to impaired functions, with a variety of hallmarks. In the testis of Drosophila, the terminal epithelium region is involved in spermatid release and maturation, while its functional diversity and regulatory mechanism remain poorly understood. In this study, we performed single-cell RNA-sequencing analysis (scRNA-seq) to characterize the transcriptomes of terminal epithelium in Drosophila testes at 2-, 10 and 40-Days. Terminal epithelium populations were defined with Metallothionein A (MtnA) and subdivided into six novel sub-cell clusters (EP0-EP5), and a series of marker genes were identified based on their expressions. The data revealed the functional characteristics of terminal epithelium populations, such as tight junction, focal adhesion, bacterial invasion, oxidative stress, mitochondrial function, proteasome, apoptosis and metabolism. Interestingly, we also found that disrupting genes for several relevant pathways in terminal epithelium led to male fertility disorders. Moreover, we also discovered a series of age-biased genes and pseudotime trajectory mediated state-biased genes during terminal epithelium aging. Differentially expressed genes during terminal epithelium aging were mainly participated in the regulation of several common signatures, e.g. mitochondria-related events, protein synthesis and degradation, and metabolic processes. We further explored the Drosophila divergence and selection in the functional constraints of age-biased genes during aging, revealing that age-biased genes in epithelial cells of 2 Days group evolved rapidly and were endowed with greater evolutionary advantages. scRNA-seq analysis revealed the diversity of testicular terminal epithelium populations, providing a gene target resource for further systematic research of their functions during aging.
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Affiliation(s)
- Xia Chen
- Department of Obstetrics and Gynecology, Nantong First People's Hospital, Affiliated Hospital 2 of Nantong University; Medical School of Nantong University, Nantong University, Nantong, Jiangsu, China
| | - Yujuan Qi
- Clinical Center of Reproductive Medicine, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, China
| | - Qiuru Huang
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong University, Nantong, China
| | - Chi Sun
- Department of Geriatrics, Affiliated Hospital of Nantong University, Nantong University, Nantong, China
| | - Yanli Zheng
- Department of Obstetrics and Gynecology, Nantong First People's Hospital, Affiliated Hospital 2 of Nantong University; Medical School of Nantong University, Nantong University, Nantong, Jiangsu, China
| | - Li Ji
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong University, Nantong, China
| | - Yi Shi
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong University, Nantong, China
| | - Xinmeng Cheng
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong University, Nantong, China
| | - Zhenbei Li
- Clinical Center of Reproductive Medicine, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, China
| | - Sen Zheng
- Clinical Center of Reproductive Medicine, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, China
| | - Yijuan Cao
- Clinical Center of Reproductive Medicine, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, China
| | - Zhifeng Gu
- Department of Rheumatology, Affiliated Hospital of Nantong University, Nantong University, Nantong, China
| | - Jun Yu
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong University, Nantong, China
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2
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Koptyug A, Sukhovei Y, Kostolomova E, Unger I, Kozlov V. Novel Strategy in Searching for Natural Compounds with Anti-Aging and Rejuvenating Potential. Int J Mol Sci 2023; 24:ijms24098020. [PMID: 37175723 PMCID: PMC10178965 DOI: 10.3390/ijms24098020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 04/18/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
We suggest a novel approach for searching natural compounds with anti-aging and rejuvenation potential using cell cultures, with a high potential for the further in vivo applications. The present paper discusses ways of defining age for cell populations with large numbers of cells and suggests a method of assessing how young or old a cell population is based on a cell age profile approach. This approach uses experimental distributions of the cells over the cell cycle stages, acquired using flow cytometry. This paper discusses how such a profile should evolve under homeostatic maintenance of cell numbers in the proliferation niches. We describe promising results from experiments on a commercial substance claiming rejuvenating and anti-aging activity acting upon the cultures of human mononuclear cells and dermal fibroblasts. The chosen substance promotes a shift towards larger proportion of cells in synthesis and proliferation stages, and increases cell culture longevity. Further, we describe promising in vivo testing results of a selected food supplement. Based on the described concept of cell age profile and available test results, a strategy to search for natural compounds with regenerative, anti-aging and rejuvenation potential is suggested and proposed for wider and thorough testing. Proposed methodology of age assessment is rather generic and can be used for quantitative assessment of the anti-aging and rejuvenation potential of different interventions. Further research aimed at the tests of the suggested strategy using more substances and different interventions, and the thorough studies of molecular mechanisms related to the action of the substance used for testing the suggested search methodology, are needed.
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Affiliation(s)
- Andrey Koptyug
- SportsTech Research Center, Department of Engineering, Mathematics and Science Education, Mid Sweden University, Akademigatan 1, 831 25 Östersund, Sweden
| | - Yurij Sukhovei
- Institute of Fundamental and Clinical Immunology, Tyumen Branch, Kotovskogo Str. 5, 625027 Tyumen, Russia
| | - Elena Kostolomova
- Department of Microbiology, Tyumen State Medical University, Kotovskogo Str. 5/2, 625023 Tyumen, Russia
| | - Irina Unger
- Institute of Fundamental and Clinical Immunology, Tyumen Branch, Kotovskogo Str. 5, 625027 Tyumen, Russia
| | - Vladimir Kozlov
- Institute of Fundamental and Clinical Immunology, Department of Clinical Immunology, Yadrintcevskaya Str. 14, 630099 Novosibirsk, Russia
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3
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Mesgarzadeh JS, Buxbaum JN, Wiseman RL. Stress-responsive regulation of extracellular proteostasis. J Cell Biol 2022; 221:213026. [PMID: 35191945 PMCID: PMC8868021 DOI: 10.1083/jcb.202112104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/02/2022] [Accepted: 02/02/2022] [Indexed: 12/18/2022] Open
Abstract
Genetic, environmental, and aging-related insults can promote the misfolding and subsequent aggregation of secreted proteins implicated in the pathogenesis of numerous diseases. This has led to considerable interest in understanding the molecular mechanisms responsible for regulating proteostasis in extracellular environments such as the blood and cerebrospinal fluid (CSF). Extracellular proteostasis is largely dictated by biological pathways comprising chaperones, folding enzymes, and degradation factors localized to the ER and extracellular space. These pathways limit the accumulation of nonnative, potentially aggregation-prone proteins in extracellular environments. Many reviews discuss the molecular mechanisms by which these pathways impact the conformational integrity of the secreted proteome. Here, we instead focus on describing the stress-responsive mechanisms responsible for adapting ER and extracellular proteostasis pathways to protect the secreted proteome from pathologic insults that challenge these environments. Further, we highlight new strategies to identify stress-responsive pathways involved in regulating extracellular proteostasis and describe the pathologic and therapeutic implications for these pathways in human disease.
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Affiliation(s)
| | - Joel N Buxbaum
- Department of Molecular Medicine, Scripps Research, La Jolla, CA
| | - R Luke Wiseman
- Department of Molecular Medicine, Scripps Research, La Jolla, CA
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4
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Herrera SC, Sainz de la Maza D, Grmai L, Margolis S, Plessel R, Burel M, O'Connor M, Amoyel M, Bach EA. Proliferative stem cells maintain quiescence of their niche by secreting the Activin inhibitor Follistatin. Dev Cell 2021; 56:2284-2294.e6. [PMID: 34363758 PMCID: PMC8387025 DOI: 10.1016/j.devcel.2021.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/14/2021] [Accepted: 07/15/2021] [Indexed: 12/20/2022]
Abstract
Aging causes stem cell dysfunction as a result of extrinsic and intrinsic changes. Decreased function of the stem cell niche is an important contributor to this dysfunction. We use the Drosophila testis to investigate what factors maintain niche cells. The testis niche comprises quiescent “hub” cells and supports two mitotic stem cell pools: germline stem cells and somatic cyst stem cells (CySCs). We identify the cell-cycle-responsive Dp/E2f1 transcription factor as a crucial non-autonomous regulator required in CySCs to maintain hub cell quiescence. Dp/E2f1 inhibits local Activin ligands through production of the Activin antagonist Follistatin (Fs). Inactivation of Dp/E2f1 or Fs in CySCs or promoting Activin receptor signaling in hub cells causes transdifferentiation of hub cells into fully functional CySCs. This Activin-dependent communication between CySCs and hub regulates the physiological decay of the niche with age and demonstrates that hub cell quiescence results from signals from surrounding stem cells. Dp/E2f1 is required in stem cells to non-autonomously maintain niche quiescence Dp/E2f1 promotes niche quiescence through Fs, an Activin antagonist Activin signaling in niche cells causes transdifferentiation into functional stem cells Fs in stem cells regulates the physiological decay of the niche with age
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Affiliation(s)
- Salvador C Herrera
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA; Centro Andaluz de Biología del Desarrollo, CSIC/Universidad Pablo de Olavide/JA, Carretera de Utrera km 1, 41013 Sevilla, Spain
| | - Diego Sainz de la Maza
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Lydia Grmai
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Shally Margolis
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Rebecca Plessel
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Michael Burel
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Michael O'Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Marc Amoyel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
| | - Erika A Bach
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
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5
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Abstract
The long-term survival of any multicellular species depends on the success of its germline in producing high-quality gametes and maximizing survival of the offspring. Studies in Drosophila melanogaster have led our growing understanding of how germline stem cell (GSC) lineages maintain their function and adjust their behavior according to varying environmental and/or physiological conditions. This review compares and contrasts the local regulation of GSCs by their specialized microenvironments, or niches; discusses how diet and diet-dependent factors, mating, and microorganisms modulate GSCs and their developing progeny; and briefly describes the tie between physiology and development during the larval phase of the germline cycle. Finally, it concludes with broad comparisons with other organisms and some future directions for further investigation.
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Affiliation(s)
- Daniela Drummond-Barbosa
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
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6
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Francis D, Chanana B, Fernandez B, Gordon B, Mak T, Palacios IM. YAP/Yorkie in the germline modulates the age-related decline of germline stem cells and niche cells. PLoS One 2019; 14:e0213327. [PMID: 30943201 PMCID: PMC6447158 DOI: 10.1371/journal.pone.0213327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 02/18/2019] [Indexed: 11/19/2022] Open
Abstract
The properties and behaviour of stem cells rely heavily on signaling from the local microenvironment. At the apical end of Drosophila testis, self-renewal and differentiation of germline stem cells (GSCs) are tightly controlled by distinct somatic cells that comprise a specialised stem cell niche known as the hub. The hub maintains GSC homeostasis through adhesion and cell signaling. The Salvador/Warts/Hippo (SWH) pathway, which suppresses the transcriptional co-activator YAP/Yki via a kinase cascade, is a known regulator of stem cell proliferation and differentiation. Here, we show that increasing YAP/Yki expression in the germline, as well as reducing Warts levels, blocks the decrease of GSC numbers observed in aging flies, with only a small increase on their proliferation. An increased expression of YAP/Yki in the germline or a reduction in Warts levels also stymies an age-related reduction in hub cell number, suggesting a bilateral relationship between GSCs and the hub. Conversely, RNAi-based knockdown of YAP/Yki in the germline leads to a significant drop in hub cell number, further suggesting the existence of such a SC-to-niche relationship. All together, our data implicate the SWH pathway in Drosophila GSC maintenance and raise questions about its role in stem cell homeostasis in aging organisms.
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Affiliation(s)
| | | | - Beatriz Fernandez
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, United Kingdom
| | | | - Tiffany Mak
- University of Cambridge, Cambridge, United Kingdom
| | - Isabel M. Palacios
- University of Cambridge, Cambridge, United Kingdom
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, United Kingdom
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7
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Yu J, Yan Y, Luan X, Qiao C, Liu Y, Zhao D, Xie B, Zheng Q, Wang M, Chen W, Shen C, He Z, Hu X, Huang X, Li H, Shao Q, Chen X, Zheng B, Fang J. Srlp is crucial for the self-renewal and differentiation of germline stem cells via RpL6 signals in Drosophila testes. Cell Death Dis 2019; 10:294. [PMID: 30931935 PMCID: PMC6443671 DOI: 10.1038/s41419-019-1527-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 12/22/2022]
Abstract
Self-renewal and differentiation in germline stem cells (GSCs) are tightly regulated by the stem cell niche and via multiple approaches. In our previous study, we screened the novel GSC regulatory gene Srlp in Drosophila testes. However, the underlying mechanistic links between Srlp and the stem cell niche remain largely undetermined. Here, using genetic manipulation of the Drosophila model, we systematically analyze the function and mechanism of Srlp in vivo and in vitro. In Drosophila, Srlp is an essential gene that regulates the self-renewal and differentiation of GSCs in the testis. In the in vitro assay, Srlp is found to control the proliferation ability and cell death in S2 cells, which is consistent with the phenotype observed in Drosophila testis. Furthermore, results of the liquid chromatography-tandem mass spectrometry (LC-MS/MS) reveal that RpL6 binds to Srlp. Srlp also regulates the expression of spliceosome and ribosome subunits and controls spliceosome and ribosome function via RpL6 signals. Collectively, our findings uncover the genetic causes and molecular mechanisms underlying the stem cell niche. This study provides new insights for elucidating the pathogenic mechanism of male sterility and the formation of testicular germ cell tumor.
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Affiliation(s)
- Jun Yu
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Yidan Yan
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Xiaojin Luan
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Chen Qiao
- Department of Clinical Pharmacy, the Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Yuanyuan Liu
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China
| | - Dan Zhao
- Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Center for Reproduction, The Fourth People's Hospital of Zhenjiang, Zhenjiang Jiangsu, 212013, China
| | - Bing Xie
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Qianwen Zheng
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Min Wang
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Wanyin Chen
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Cong Shen
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China
| | - Zeyu He
- Department of Clinical Medicine, China Medical University, Shenyang Liaoning, 110001, China
| | - Xing Hu
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China
| | - Xiaoyan Huang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing Jiangsu, 211166, China
| | - Hong Li
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China
| | - Qixiang Shao
- Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China.,Department of Immunology and Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang Jiangsu, 212013, China
| | - Xia Chen
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China. .,Reproductive Sciences Institute of Jiangsu University, Zhenjiang Jiangsu, 212001, China.
| | - Bo Zheng
- Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Jiangsu, 215002, China.
| | - Jie Fang
- Department of Gynecology, The Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang Jiangsu, 212001, China.
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8
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Weaver LN, Drummond-Barbosa D. Maintenance of Proper Germline Stem Cell Number Requires Adipocyte Collagen in Adult Drosophila Females. Genetics 2018; 209:1155-1166. [PMID: 29884747 PMCID: PMC6063239 DOI: 10.1534/genetics.118.301137] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 05/31/2018] [Indexed: 02/06/2023] Open
Abstract
Stem cells reside in specialized niches and are regulated by a variety of physiological inputs. Adipocytes influence whole-body physiology and stem cell lineages; however, the molecular mechanisms linking adipocytes to stem cells are poorly understood. Here, we report that collagen IV produced in adipocytes is transported to the ovary to maintain proper germline stem cell (GSC) number in adult Drosophila females. Adipocyte-derived collagen IV acts through β-integrin signaling to maintain normal levels of E-cadherin at the niche, thereby ensuring proper adhesion to GSCs. These findings demonstrate that extracellular matrix components produced in adipocytes can be transported to and incorporated into an established adult tissue to influence stem cell number.
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Affiliation(s)
- Lesley N Weaver
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Daniela Drummond-Barbosa
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
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9
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Kim J, Bilder D, Neufeld TP. Mechanical stress regulates insulin sensitivity through integrin-dependent control of insulin receptor localization. Genes Dev 2018; 32:156-164. [PMID: 29440263 PMCID: PMC5830928 DOI: 10.1101/gad.305870.117] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 01/02/2018] [Indexed: 12/22/2022]
Abstract
Kim et al. show that insulin signaling in Drosophila adipocytes is abolished in the absence of physical activity and mechanical stress. The insulin receptor and downstream components are recruited to the plasma membrane upon stress sensing mediated by integrins. Insulin resistance, the failure to activate insulin signaling in the presence of ligand, leads to metabolic diseases, including type 2 diabetes. Physical activity and mechanical stress have been shown to protect against insulin resistance, but the molecular mechanisms remain unclear. Here, we address this relationship in the Drosophila larval fat body, an insulin-sensitive organ analogous to vertebrate adipose tissue and livers. We found that insulin signaling in Drosophila fat body cells is abolished in the absence of physical activity and mechanical stress even when excess insulin is present. Physical movement is required for insulin sensitivity in both intact larvae and fat bodies cultured ex vivo. Interestingly, the insulin receptor and other downstream components are recruited to the plasma membrane in response to mechanical stress, and this membrane localization is rapidly lost upon disruption of larval or tissue movement. Sensing of mechanical stimuli is mediated in part by integrins, whose activation is necessary and sufficient for mechanical stress-dependent insulin signaling. Insulin resistance develops naturally during the transition from the active larval stage to the immotile pupal stage, suggesting that regulation of insulin sensitivity by mechanical stress may help coordinate developmental programming with metabolism.
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Affiliation(s)
- Jung Kim
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455, USA.,Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - David Bilder
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, USA
| | - Thomas P Neufeld
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455, USA
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10
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Chen KC, Qu S, Chowdhury S, Noxon IC, Schonhoft JD, Plate L, Powers ET, Kelly JW, Lander GC, Wiseman RL. The endoplasmic reticulum HSP40 co-chaperone ERdj3/DNAJB11 assembles and functions as a tetramer. EMBO J 2017; 36:2296-2309. [PMID: 28655754 DOI: 10.15252/embj.201695616] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 05/15/2017] [Accepted: 05/22/2017] [Indexed: 11/09/2022] Open
Abstract
ERdj3/DNAJB11 is an endoplasmic reticulum (ER)-targeted HSP40 co-chaperone that performs multifaceted functions involved in coordinating ER and extracellular proteostasis. Here, we show that ERdj3 assembles into a native tetramer that is distinct from the dimeric structure observed for other HSP40 co-chaperones. An electron microscopy structural model of full-length ERdj3 shows that these tetramers are arranged as a dimer of dimers formed by distinct inter-subunit interactions involving ERdj3 domain II and domain III Targeted deletion of residues 175-190 within domain II renders ERdj3 a stable dimer that is folded and efficiently secreted from mammalian cells. This dimeric ERdj3 shows impaired substrate binding both in the ER and extracellular environments and reduced interactions with the ER HSP70 chaperone BiP. Furthermore, we show that overexpression of dimeric ERdj3 exacerbates ER stress-dependent reductions in the secretion of a destabilized, aggregation-prone protein and increases its accumulation as soluble oligomers in extracellular environments. These results reveal ERdj3 tetramerization as an important structural framework for ERdj3 functions involved in coordinating ER and extracellular proteostasis in the presence and absence of ER stress.
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Affiliation(s)
- Kai-Chun Chen
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Song Qu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Saikat Chowdhury
- Department of Integrative, Structural, and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Isabelle C Noxon
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Joseph D Schonhoft
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Lars Plate
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.,Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Evan T Powers
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA.,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Gabriel C Lander
- Department of Integrative, Structural, and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
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11
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Abstract
Imbalances in secretory proteostasis induced by genetic, environmental, or aging-related insults are pathologically associated with etiologically diverse protein misfolding diseases. To protect the secretory proteome from these insults, organisms evolved stress-responsive signaling pathways that regulate the composition and activity of biologic pathways involved in secretory proteostasis maintenance. The most prominent of these is the endoplasmic reticulum (ER) unfolded protein response (UPR), which functions to regulate ER proteostasis in response to ER stress. While the signaling mechanisms involved in UPR activation are well defined, the impact of UPR activation on secretory proteostasis is only now becoming clear. Here, we highlight recent reports defining how activation of select UPR signaling pathways influences proteostasis within the ER and downstream secretory environments. Furthermore, we describe recent evidence that highlights the therapeutic potential for targeting UPR signaling pathways to correct pathologic disruption in secretory proteostasis associated with diverse types of protein misfolding diseases.
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Affiliation(s)
- Lars Plate
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA.
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12
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Lee JY, Geng J, Lee J, Wang AR, Chang KT. Activity-Induced Synaptic Structural Modifications by an Activator of Integrin Signaling at the Drosophila Neuromuscular Junction. J Neurosci 2017; 37:3246-63. [PMID: 28219985 DOI: 10.1523/JNEUROSCI.3128-16.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/08/2017] [Accepted: 02/14/2017] [Indexed: 11/21/2022] Open
Abstract
Activity-induced synaptic structural modification is crucial for neural development and synaptic plasticity, but the molecular players involved in this process are not well defined. Here, we report that a protein named Shriveled (Shv) regulates synaptic growth and activity-dependent synaptic remodeling at the Drosophila neuromuscular junction. Depletion of Shv causes synaptic overgrowth and an accumulation of immature boutons. We find that Shv physically and genetically interacts with βPS integrin. Furthermore, Shv is secreted during intense, but not mild, neuronal activity to acutely activate integrin signaling, induce synaptic bouton enlargement, and increase postsynaptic glutamate receptor abundance. Consequently, loss of Shv prevents activity-induced synapse maturation and abolishes post-tetanic potentiation, a form of synaptic plasticity. Our data identify Shv as a novel trans-synaptic signal secreted upon intense neuronal activity to promote synapse remodeling through integrin receptor signaling.SIGNIFICANCE STATEMENT The ability of neurons to rapidly modify synaptic structure in response to neuronal activity, a process called activity-induced structural remodeling, is crucial for neuronal development and complex brain functions. The molecular players that are important for this fundamental biological process are not well understood. Here we show that the Shriveled (Shv) protein is required during development to maintain normal synaptic growth. We further demonstrate that Shv is selectively released during intense neuronal activity, but not mild neuronal activity, to acutely activate integrin signaling and trigger structural modifications at the Drosophila neuromuscular junction. This work identifies Shv as a key modulator of activity-induced structural remodeling and suggests that neurons use distinct molecular cues to differentially modulate synaptic growth and remodeling to meet synaptic demand.
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