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Lee JH. Host-Microbe Interactions Regulate Intestinal Stem Cells and Tissue Turnover in Drosophila. Int J Stem Cells 2024; 17:51-58. [PMID: 38123486 PMCID: PMC10899887 DOI: 10.15283/ijsc23172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023] Open
Abstract
With the activity of intestinal stem cells and continuous turnover, the gut epithelium is one of the most dynamic tissues in animals. Due to its simple yet conserved tissue structure and enteric cell composition as well as advanced genetic and histologic techniques, Drosophila serves as a valuable model system for investigating the regulation of intestinal stem cells. The Drosophila gut epithelium is in constant contact with indigenous microbiota and encounters externally introduced "non-self" substances, including foodborne pathogens. Therefore, in addition to its role in digestion and nutrient absorption, another essential function of the gut epithelium is to control the expansion of microbes while maintaining its structural integrity, necessitating a tissue turnover process involving intestinal stem cell activity. As a result, the microbiome and pathogens serve as important factors in regulating intestinal tissue turnover. In this manuscript, I discuss crucial discoveries revealing the interaction between gut microbes and the host's innate immune system, closely associated with the regulation of intestinal stem cell proliferation and differentiation, ultimately contributing to epithelial homeostasis.
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Affiliation(s)
- Ji-Hoon Lee
- National Creative Research Initiative Center for Hologenomics and School of Biological Sciences, Seoul National University, Seoul, Korea
- The Research Institute of Basic Sciences, Seoul National University, Seoul, Korea
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2
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Zwick RK, Kasparek P, Palikuqi B, Viragova S, Weichselbaum L, McGinnis CS, McKinley KL, Rathnayake A, Vaka D, Nguyen V, Trentesaux C, Reyes E, Gupta AR, Gartner ZJ, Locksley RM, Gardner JM, Itzkovitz S, Boffelli D, Klein OD. Epithelial zonation along the mouse and human small intestine defines five discrete metabolic domains. Nat Cell Biol 2024; 26:250-262. [PMID: 38321203 DOI: 10.1038/s41556-023-01337-z] [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: 08/07/2022] [Accepted: 12/13/2023] [Indexed: 02/08/2024]
Abstract
A key aspect of nutrient absorption is the exquisite division of labour across the length of the small intestine, with individual nutrients taken up at different proximal:distal positions. For millennia, the small intestine was thought to comprise three segments with indefinite borders: the duodenum, jejunum and ileum. By examining the fine-scale longitudinal transcriptional patterns that span the mouse and human small intestine, we instead identified five domains of nutrient absorption that mount distinct responses to dietary changes, and three regional stem cell populations. Molecular domain identity can be detected with machine learning, which provides a systematic method to computationally identify intestinal domains in mice. We generated a predictive model of transcriptional control of domain identity and validated the roles of Ppar-δ and Cdx1 in patterning lipid metabolism-associated genes. These findings represent a foundational framework for the zonation of absorption across the mammalian small intestine.
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Affiliation(s)
- Rachel K Zwick
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Petr Kasparek
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Brisa Palikuqi
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Sara Viragova
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Laura Weichselbaum
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Christopher S McGinnis
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Kara L McKinley
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA
| | - Asoka Rathnayake
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Dedeepya Vaka
- Department of Pediatrics, Cedars-Sinai Guerin Children's, Los Angeles, CA, USA
| | - Vinh Nguyen
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
- UCSF CoLabs, University of California, San Francisco, San Francisco, CA, USA
| | - Coralie Trentesaux
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Efren Reyes
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Alexander R Gupta
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Zev J Gartner
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, San Francisco, CA, USA
- Chan Zuckerberg BioHub and Center for Cellular Construction 94158, University of California San Francisco, San Francisco, CA, USA
| | - Richard M Locksley
- Department of Medicine and Department of Microbiology & Immunology, University of California San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA, USA
| | - James M Gardner
- Department of Surgery, University of California San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Shalev Itzkovitz
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Dario Boffelli
- Department of Pediatrics, Cedars-Sinai Guerin Children's, Los Angeles, CA, USA
| | - Ophir D Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California, San Francisco, San Francisco, CA, USA.
- Department of Pediatrics, Cedars-Sinai Guerin Children's, Los Angeles, CA, USA.
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3
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Reyes-Rivera J, Grillo-Alvarado V, Soriano-López AE, García-Arrarás JE. Evidence of interactions among apoptosis, cell proliferation, and dedifferentiation in the rudiment during whole-organ intestinal regeneration in the sea cucumber. Dev Biol 2024; 505:99-109. [PMID: 37925124 PMCID: PMC11163280 DOI: 10.1016/j.ydbio.2023.11.001] [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: 04/08/2023] [Revised: 09/05/2023] [Accepted: 11/01/2023] [Indexed: 11/06/2023]
Abstract
Sea cucumbers have an extraordinary regenerative capability. Under stressful conditions, Holothuria glaberrima can eviscerate their internal organs, including the digestive tract. From the mesentery, a rudiment grows and gives rise to a new intestine within a few weeks. In the last decades, the cellular events that occur during intestinal regeneration have been characterized, including apoptosis, cell proliferation, and muscle cell dedifferentiation. Nevertheless, their contribution to the formation and early growth of the rudiment is still unknown. Furthermore, these cellular events' relationship and potential interdependence remain a mystery. Using modulators to inhibit apoptosis and cell proliferation, we tested whether rudiment growth or other regenerative cellular events like muscle cell dedifferentiation were affected. We found that inhibition of apoptosis by zVAD and cell proliferation by aphidicolin and mitomycin did not affect the overall size of the rudiment seven days post-evisceration (7-dpe). Interestingly, animals treated with aphidicolin showed higher levels of muscle cell dedifferentiation in the distal mesentery, which could act as a compensatory mechanism. On the other hand, inhibition of apoptosis led to a decrease in cell proliferation in the rudiment and a delay in the spatiotemporal progression of muscle cell dedifferentiation throughout the rudiment-mesentery structure. Our findings suggest that neither apoptosis nor cell proliferation significantly contributes to early rudiment growth during intestinal regeneration in the sea cucumber. Nevertheless, apoptosis may play an essential role in modulating cell proliferation in the rudiment (a process known as apoptosis-induced proliferation) and the timing for the progression of muscle cell dedifferentiation. These findings provide new insights into the role and relationship of cellular events during intestinal regeneration in an emerging regeneration model.
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Affiliation(s)
- Josean Reyes-Rivera
- Department of Biology, University of Puerto Rico, Río Piedras, PR, USA; Molecular and Cell Biology Department, University of California, Berkeley, CA, USA
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4
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Quintero M, Bangi E. Disruptions in cell fate decisions and transformed enteroendocrine cells drive intestinal tumorigenesis in Drosophila. Cell Rep 2023; 42:113370. [PMID: 37924517 PMCID: PMC10841758 DOI: 10.1016/j.celrep.2023.113370] [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: 01/31/2023] [Revised: 07/11/2023] [Accepted: 10/18/2023] [Indexed: 11/06/2023] Open
Abstract
Most epithelial tissues are maintained by stem cells that produce the different cell lineages required for proper tissue function. Constant communication between different cell types ensures precise regulation of stem cell behavior and cell fate decisions. These cell-cell interactions are often disrupted during tumorigenesis, but mechanisms by which they are co-opted to support tumor growth in different genetic contexts are poorly understood. Here, we introduce PromoterSwitch, a genetic platform we established to generate large, transformed clones derived from individual adult Drosophila intestinal stem/progenitor cells. We show that cancer-driving genetic alterations representing common colon tumor genome landscapes disrupt cell fate decisions within transformed tissue and result in the emergence of abnormal cell fates. We also show that transformed enteroendocrine cells, a differentiated, hormone-secreting cell lineage, support tumor growth by regulating intestinal stem cell proliferation through multiple genotype-dependent mechanisms, which represent potential vulnerabilities that could be exploited for therapy.
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Affiliation(s)
- Maria Quintero
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA
| | - Erdem Bangi
- Department of Biological Science, Florida State University, Tallahassee, FL 32304, USA.
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5
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Zwick RK, Kasparek P, Palikuqi B, Viragova S, Weichselbaum L, McGinnis CS, McKinley KL, Rathnayake A, Vaka D, Nguyen V, Trentesaux C, Reyes E, Gupta AR, Gartner ZJ, Locksley RM, Gardner JM, Itzkovitz S, Boffelli D, Klein OD. Epithelial zonation along the mouse and human small intestine defines five discrete metabolic domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.20.558726. [PMID: 37790430 PMCID: PMC10542170 DOI: 10.1101/2023.09.20.558726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
A key aspect of nutrient absorption is the exquisite division of labor across the length of the small intestine, with individual classes of micronutrients taken up at different positions. For millennia, the small intestine was thought to comprise three segments with indefinite borders: the duodenum, jejunum, and ileum. By examining fine-scale longitudinal segmentation of the mouse and human small intestines, we identified transcriptional signatures and upstream regulatory factors that define five domains of nutrient absorption, distinct from the three traditional sections. Spatially restricted expression programs were most prominent in nutrient-absorbing enterocytes but initially arose in intestinal stem cells residing in three regional populations. While a core signature was maintained across mice and humans with different diets and environments, domain properties were influenced by dietary changes. We established the functions of Ppar-ẟ and Cdx1 in patterning lipid metabolism in distal domains and generated a predictive model of additional transcription factors that direct domain identity. Molecular domain identity can be detected with machine learning, representing the first systematic method to computationally identify specific intestinal regions in mice. These findings provide a foundational framework for the identity and control of longitudinal zonation of absorption along the proximal:distal small intestinal axis.
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6
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Mahanta DK, Bhoi TK, Komal J, Samal I, Nikhil RM, Paschapur AU, Singh G, Kumar PVD, Desai HR, Ahmad MA, Singh PP, Majhi PK, Mukherjee U, Singh P, Saini V, Shahanaz, Srinivasa N, Yele Y. Insect-pathogen crosstalk and the cellular-molecular mechanisms of insect immunity: uncovering the underlying signaling pathways and immune regulatory function of non-coding RNAs. Front Immunol 2023; 14:1169152. [PMID: 37691928 PMCID: PMC10491481 DOI: 10.3389/fimmu.2023.1169152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 08/07/2023] [Indexed: 09/12/2023] Open
Abstract
Multicellular organisms are constantly subjected to pathogens that might be harmful. Although insects lack an adaptive immune system, they possess highly effective anti-infective mechanisms. Bacterial phagocytosis and parasite encapsulation are some forms of cellular responses. Insects often defend themselves against infections through a humoral response. This phenomenon includes the secretion of antimicrobial peptides into the hemolymph. Specific receptors for detecting infection are required for the recognition of foreign pathogens such as the proteins that recognize glucans and peptidoglycans, together referred to as PGRPs and βGRPs. Activation of these receptors leads to the stimulation of signaling pathways which further activates the genes encoding for antimicrobial peptides. Some instances of such pathways are the JAK-STAT, Imd, and Toll. The host immune response that frequently accompanies infections has, however, been circumvented by diseases, which may have assisted insects evolve their own complicated immune systems. The role of ncRNAs in insect immunology has been discussed in several notable studies and reviews. This paper examines the most recent research on the immune regulatory function of ncRNAs during insect-pathogen crosstalk, including insect- and pathogen-encoded miRNAs and lncRNAs, and provides an overview of the important insect signaling pathways and effector mechanisms activated by diverse pathogen invaders.
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Affiliation(s)
- Deepak Kumar Mahanta
- Department of Entomology, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
| | - Tanmaya Kumar Bhoi
- Forest Protection Division, Indian Council of Forestry Research and Education (ICFRE) - Arid Forest Research Institute (ICFRE-AFRI), Jodhpur, Rajasthan, India
| | - J. Komal
- Department of Entomology, Navsari Agricultural University, Navsari, Gujarat, India
| | - Ipsita Samal
- ICAR-National Research Centre on Litchi, Mushahari, Ramna, Muzaffarpur, Bihar, India
| | - R. M. Nikhil
- Division of Entomology, Indian Agricultural Research Institute, New Delhi, India
| | - Amit Umesh Paschapur
- Crop Protection Division, Indian Council of Agricultural Research (ICAR)-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Almora, Uttarakhand, India
| | - Gaurav Singh
- The Directorate of Research, Maharana Pratap Horticultural University, Karnal, Haryana, India
| | - P. V. Dinesh Kumar
- Department of Plant Pathology University of Agricultural Sciences, Bengaluru, Karnataka, India
| | - H. R. Desai
- Department of Entomology, Main Cotton Research Station, Navsari Agricultural University, Gujarat, India
| | - Mohammad Abbas Ahmad
- Department of Entomology, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
| | - P. P. Singh
- Department of Entomology, Tirhut College of Agriculture, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
| | - Prasanta Kumar Majhi
- Department of Plant Breeding and Genetics, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha, India
| | - U. Mukherjee
- Department of Entomology, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
| | - Pushpa Singh
- Department of Entomology, Dr. Rajendra Prasad Central Agricultural University, Samastipur, Bihar, India
| | - Varun Saini
- Department of Entomology, Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India
| | - Shahanaz
- Department of Entomology, College of Horticulture Mojerla, Sri Konda Laxman Telengana State Horticultural University, Wanaparthy, Telengana, India
| | - N. Srinivasa
- Department of Entomology and Agricultural Zoology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Yogesh Yele
- School of Crop Health Management Research, Council of Agricultural Research-National Institute of Biotic Stress Management (ICAR)- National Institute of Biotic Stress Management, Raipur, India
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7
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Gong J, Nirala NK, Chen J, Wang F, Gu P, Wen Q, Ip YT, Xiang Y. TrpA1 is a shear stress mechanosensing channel regulating intestinal stem cell proliferation in Drosophila. SCIENCE ADVANCES 2023; 9:eadc9660. [PMID: 37224252 PMCID: PMC10208578 DOI: 10.1126/sciadv.adc9660] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 04/18/2023] [Indexed: 05/26/2023]
Abstract
Adult stem cells are essential for tissue maintenance and repair. Although genetic pathways for controlling adult stem cells are extensively investigated in various tissues, much less is known about how mechanosensing could regulate adult stem cells and tissue growth. Here, we demonstrate that shear stress sensing regulates intestine stem cell proliferation and epithelial cell number in adult Drosophila. Ca2+ imaging in ex vivo midguts shows that shear stress, but not other mechanical forces, specifically activates enteroendocrine cells among all epithelial cell types. This activation is mediated by transient receptor potential A1 (TrpA1), a Ca2+-permeable channel expressed in enteroendocrine cells. Furthermore, specific disruption of shear stress, but not chemical, sensitivity of TrpA1 markedly reduces proliferation of intestinal stem cells and midgut cell number. Therefore, we propose that shear stress may act as a natural mechanical stimulation to activate TrpA1 in enteroendocrine cells, which, in turn, regulates intestine stem cell behavior.
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Affiliation(s)
- Jiaxin Gong
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Niraj K. Nirala
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jiazhang Chen
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Fei Wang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Pengyu Gu
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Qi Wen
- Department of Physics, Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Y. Tony Ip
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Yang Xiang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
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8
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Jneid R, Loudhaief R, Zucchini-Pascal N, Nawrot-Esposito MP, Fichant A, Rousset R, Bonis M, Osman D, Gallet A. Bacillus thuringiensis toxins divert progenitor cells toward enteroendocrine fate by decreasing cell adhesion with intestinal stem cells in Drosophila. eLife 2023; 12:80179. [PMID: 36847614 PMCID: PMC9977296 DOI: 10.7554/elife.80179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 02/05/2023] [Indexed: 03/01/2023] Open
Abstract
Bacillus thuringiensis subsp. kurstaki (Btk) is a strong pathogen toward lepidopteran larvae thanks to specific Cry toxins causing leaky gut phenotypes. Hence, Btk and its toxins are used worldwide as microbial insecticide and in genetically modified crops, respectively, to fight crop pests. However, Btk belongs to the B. cereus group, some strains of which are well known human opportunistic pathogens. Therefore, ingestion of Btk along with food may threaten organisms not susceptible to Btk infection. Here we show that Cry1A toxins induce enterocyte death and intestinal stem cell (ISC) proliferation in the midgut of Drosophila melanogaster, an organism non-susceptible to Btk. Surprisingly, a high proportion of the ISC daughter cells differentiate into enteroendocrine cells instead of their initial enterocyte destiny. We show that Cry1A toxins weaken the E-Cadherin-dependent adherens junction between the ISC and its immediate daughter progenitor, leading the latter to adopt an enteroendocrine fate. Hence, although not lethal to non-susceptible organisms, Cry toxins can interfere with conserved cell adhesion mechanisms, thereby disrupting intestinal homeostasis and endocrine functions.
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Affiliation(s)
- Rouba Jneid
- Universite Cote d'Azur, CNRS, INRAESophia AntipolisFrance
- Faculty of Sciences III and Azm Center for Research in Biotechnology and its Applications, LBA3B, EDST, Lebanese UniversityTripoliLebanon
| | | | | | | | - Arnaud Fichant
- Universite Cote d'Azur, CNRS, INRAESophia AntipolisFrance
- Laboratory for Food Safety, University Paris-Est, French Agency for Food, Environmental and Occupational Health & SafetyMaisons-AlfortFrance
| | | | - Mathilde Bonis
- Laboratory for Food Safety, University Paris-Est, French Agency for Food, Environmental and Occupational Health & SafetyMaisons-AlfortFrance
| | - Dani Osman
- Faculty of Sciences III and Azm Center for Research in Biotechnology and its Applications, LBA3B, EDST, Lebanese UniversityTripoliLebanon
| | - Armel Gallet
- Universite Cote d'Azur, CNRS, INRAESophia AntipolisFrance
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9
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N. Landis G, Ko S, Peng O, Bognar B, Khmelkov M, S. Bell H, Tower J. A screen of small molecule and genetic modulators of life span in female Drosophila identifies etomoxir, RH5849 and unanticipated temperature effects. Fly (Austin) 2022; 16:397-413. [PMID: 36412257 PMCID: PMC9683069 DOI: 10.1080/19336934.2022.2149209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/02/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022] Open
Abstract
Mifepristone increases life span in female Drosophila melanogaster, and its molecular target(s) remain unclear. Here small molecule and genetic interventions were tested for ability to mimic mifepristone, or to decrease life span in a way that can be rescued by mifepristone. Etomoxir inhibits lipid metabolism, and significantly increased life span in virgin and mated females, but not males, at 50 µM concentration. Pioglitazone is reported to activate both mammalian PPARγ and its Drosophila homolog Eip75B. Pioglitazone produced minor and inconsistent benefits for female Drosophila life span, and only at the lowest concentrations tested. Ecdysone is a Drosophila steroid hormone reported to regulate responses to mating, and RH5849 is a potent mimic of ecdysone. RH5849 reduced virgin female life span, and this was partly rescued by mifepristone. Mifepristone did not compete with RH5849 for activation of an ecdysone receptor (EcR)-responsive transgenic reporter, indicating that the relevant target for mifepristone is not EcR. The conditional GAL4/GAL80ts system was used in attempt to test the effect of an Eip75B RNAi construct on female life span. However, the 29°C temperature used for induction reduced or eliminated mating-induced midgut hypertrophy, the negative life span effects of mating, and the positive life span effects of mifepristone. Even when applied after mating was complete, a shift to 29°C temperature reduced mating-induced midgut hypertrophy by half, and the life span effects of mating by 4.8-fold. Taken together, these results identify promising small molecules for further analysis, and inform the design of experiments involving the GAL4/GAL80ts system.
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Affiliation(s)
- Gary N. Landis
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Sebastian Ko
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Oscar Peng
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Brett Bognar
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Michael Khmelkov
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Hans S. Bell
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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10
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Zeng T, Jaffar S, Xu Y, Qi Y. The Intestinal Immune Defense System in Insects. Int J Mol Sci 2022; 23:ijms232315132. [PMID: 36499457 PMCID: PMC9740067 DOI: 10.3390/ijms232315132] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
Over a long period of evolution, insects have developed unique intestinal defenses against invasion by foreign microorganisms, including physical defenses and immune responses. The physical defenses of the insect gut consist mainly of the peritrophic matrix (PM) and mucus layer, which are the first barriers to pathogens. Gut microbes also prevent the colonization of pathogens. Importantly, the immune-deficiency (Imd) pathways produce antimicrobial peptides to eliminate pathogens; mechanisms related to reactive oxygen species are another important pathway for insect intestinal immunity. The janus kinase/STAT signaling pathway is involved in intestinal immunity by producing bactericidal substances and regulating tissue repair. Melanization can produce many bactericidal active substances into the intestine; meanwhile, there are multiple responses in the intestine to fight against viral and parasitic infections. Furthermore, intestinal stem cells (ISCs) are also indispensable in intestinal immunity. Only the coordinated combination of the intestinal immune defense system and intestinal tissue renewal can effectively defend against pathogenic microorganisms.
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11
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Tian A, Morejon V, Kohoutek S, Huang Y, Deng W, Jiang J. Damage-induced regeneration of the intestinal stem cell pool through enteroblast mitosis in the Drosophila midgut. EMBO J 2022; 41:e110834. [PMID: 35950466 PMCID: PMC9531297 DOI: 10.15252/embj.2022110834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 11/09/2022] Open
Abstract
Many adult tissues and organs including the intestine rely on resident stem cells to maintain homeostasis and regeneration. In mammals, the progenies of intestinal stem cells (ISCs) can dedifferentiate to generate ISCs upon ablation of resident stem cells. However, whether and how mature tissue cells generate ISCs under physiological conditions remains unknown. Here, we show that infection of the Drosophila melanogaster intestine with pathogenic bacteria induces entry of enteroblasts (EBs), which are ISC progenies, into the mitotic cycle through upregulation of epidermal growth factor receptor (EGFR)-Ras signaling. We also show that ectopic activation of EGFR-Ras signaling in EBs is sufficient to drive enteroblast mitosis cell autonomously. Furthermore, we find that the dividing enteroblasts do not gain ISC identity as a prerequisite to divide, and the regenerative ISCs are produced through EB mitosis. Taken together, our work uncovers a new role for EGFR-Ras signaling in driving EB mitosis and replenishing the ISC pool during fly intestinal regeneration, which may have important implications for tissue homeostasis and tumorigenesis in vertebrates.
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Affiliation(s)
- Aiguo Tian
- Department of Biochemistry and Molecular Biology, Tulane University School of MedicineLouisiana Cancer Research CenterNew OrleansLAUSA
- Tulane Aging CenterTulane University School of MedicineNew OrleansLAUSA
| | - Virginia Morejon
- Department of Biochemistry and Molecular Biology, Tulane University School of MedicineLouisiana Cancer Research CenterNew OrleansLAUSA
| | - Sarah Kohoutek
- Department of Biochemistry and Molecular Biology, Tulane University School of MedicineLouisiana Cancer Research CenterNew OrleansLAUSA
| | - Yi‐Chun Huang
- Department of Biochemistry and Molecular Biology, Tulane University School of MedicineLouisiana Cancer Research CenterNew OrleansLAUSA
| | - Wu‐Min Deng
- Department of Biochemistry and Molecular Biology, Tulane University School of MedicineLouisiana Cancer Research CenterNew OrleansLAUSA
| | - Jin Jiang
- Department of Molecular Biology and Department of PharmacologyUniversity of Texas Southwestern Medical CenterDallasTXUSA
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12
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Laws KM, Bashaw GJ. Diverse roles for axon guidance pathways in adult tissue architecture and function. NATURAL SCIENCES (WEINHEIM, GERMANY) 2022; 2:e20220021. [PMID: 37456985 PMCID: PMC10346896 DOI: 10.1002/ntls.20220021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Classical axon guidance ligands and their neuronal receptors were first identified due to their fundamental roles in regulating connectivity in the developing nervous system. Since their initial discovery, it has become clear that these signaling molecules play important roles in the development of a broad array of tissue and organ systems across phylogeny. In addition to these diverse developmental roles, there is a growing appreciation that guidance signaling pathways have important functions in adult organisms, including the regulation of tissue integrity and homeostasis. These roles in adult organisms include both tissue-intrinsic activities of guidance molecules, as well as systemic effects on tissue maintenance and function mediated by the nervous and vascular systems. While many of these adult functions depend on mechanisms that mirror developmental activities, such as regulating adhesion and cell motility, there are also examples of adult roles that may reflect signaling activities that are distinct from known developmental mechanisms, including the contributions of guidance signaling pathways to lineage commitment in the intestinal epithelium and bone remodeling in vertebrates. In this review, we highlight studies of guidance receptors and their ligands in adult tissues outside of the nervous system, focusing on in vivo experimental contexts. Together, these studies lay the groundwork for future investigation into the conserved and tissue-specific mechanisms of guidance receptor signaling in adult tissues.
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Affiliation(s)
- Kaitlin M. Laws
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Current address: Department of Biology, Randolph-Macon College, Ashland, VA 23005, USA
| | - Greg J. Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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13
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Holsopple JM, Cook KR, Popodi EM. Identification of novel split-GAL4 drivers for the characterization of enteroendocrine cells in the Drosophila melanogaster midgut. G3 (BETHESDA, MD.) 2022; 12:jkac102. [PMID: 35485968 PMCID: PMC9157172 DOI: 10.1093/g3journal/jkac102] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/18/2022] [Indexed: 01/09/2023]
Abstract
The Drosophila melanogaster midgut is commonly studied as a model epithelial tissue for many reasons, one of which is the presence of a diverse population of secretory cells called enteroendocrine cells. Subpopulations of these cells secrete various combinations of peptide hormones which have systemic effects on the organism. Many of these hormones are also produced in the Drosophila brain. The split-GAL4 system has been useful for identifying and manipulating discrete groups of cells, but previously characterized split-GAL4 drivers have not driven expression in high proportions of enteroendocrine cells. In this study, we screened candidate split-GAL4 drivers for enteroendocrine cell expression using known reference drivers for this cell type and discovered a new split-GAL4 driver pair that confers expression in a greater number of enteroendocrine cells than previously characterized driver pairs. The new pair demonstrates less brain expression, thereby providing better tools for disentangling the physiological roles of gut- and brain-secreted peptides. We also identified additional split-GAL4 drivers that promote expression in discrete subpopulations of enteroendocrine cells. Overall, the tools reported here will help researchers better target enteroendocrine cell subpopulations.
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Affiliation(s)
- Jessica M Holsopple
- Department of Biology, Bloomington Drosophila Stock Center, Indiana University, Bloomington, IN 47405, USA
| | - Kevin R Cook
- Department of Biology, Bloomington Drosophila Stock Center, Indiana University, Bloomington, IN 47405, USA
| | - Ellen M Popodi
- Department of Biology, Bloomington Drosophila Stock Center, Indiana University, Bloomington, IN 47405, USA
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Yu T, Cazares O, Tang AD, Kim HY, Wald T, Verma A, Liu Q, Barcellos-Hoff MH, Floor SN, Jung HS, Brooks AN, Klein OD. SRSF1 governs progenitor-specific alternative splicing to maintain adult epithelial tissue homeostasis and renewal. Dev Cell 2022; 57:624-637.e4. [PMID: 35202586 PMCID: PMC8974236 DOI: 10.1016/j.devcel.2022.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 11/04/2021] [Accepted: 01/18/2022] [Indexed: 12/30/2022]
Abstract
Alternative splicing generates distinct mRNA variants and is essential for development, homeostasis, and renewal. Proteins of the serine/arginine (SR)-rich splicing factor family are major splicing regulators that are broadly required for organ development as well as cell and organism viability. However, how these proteins support adult organ function remains largely unknown. Here, we used the continuously growing mouse incisor as a model to dissect the functions of the prototypical SR family protein SRSF1 during tissue homeostasis and renewal. We identified an SRSF1-governed alternative splicing network that is specifically required for dental proliferation and survival of progenitors but dispensable for the viability of differentiated cells. We also observed a similar progenitor-specific role of SRSF1 in the small intestinal epithelium, indicating a conserved function of SRSF1 across adult epithelial tissues. Thus, our findings define a regulatory mechanism by which SRSF1 specifically controls progenitor-specific alternative splicing events to support adult tissue homeostasis and renewal.
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Affiliation(s)
- Tingsheng Yu
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Oscar Cazares
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Alison D Tang
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Hyun-Yi Kim
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Oral Science Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Tomas Wald
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Adya Verma
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Qi Liu
- Department of Radiation Oncology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94115, USA
| | - Mary Helen Barcellos-Hoff
- Department of Radiation Oncology, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94115, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Han-Sung Jung
- Division in Anatomy and Developmental Biology, Department of Oral Biology, Oral Science Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Angela N Brooks
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | - Ophir D Klein
- Department of Orofacial Sciences and Program in Craniofacial Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Pediatrics and Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, USA.
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15
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Parasram K, Bachetti D, Carmona-Alcocer V, Karpowicz P. Fluorescent Reporters for Studying Circadian Rhythms in Drosophila melanogaster. Methods Mol Biol 2022; 2482:353-371. [PMID: 35610439 DOI: 10.1007/978-1-0716-2249-0_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Circadian rhythms are daily oscillations in physiology and gene expression that are governed by a molecular feedback loop known as the circadian clock. In Drosophila melanogaster, the core clock consists of transcription factors clock (Clk) and cycle (cyc) which form protein heterodimers that activate transcription of their repressors, period (per) and timeless (tim). Once produced, protein heterodimers of per/tim repress Clk/cyc activity. One cycle of activation and repression takes approximately ("circa") 24-h ("diem") and repeats even in the absence of external stimuli. The circadian clock is active in many cells throughout the body; however, tracking it dynamically represents a challenge. Traditional fluorescent reporters are slowly degraded and consequently cannot be used to assess dynamic temporal changes exhibited by the circadian clock. The use of rapidly degraded fluorescent protein reporters containing destabilized GFP (dGFP) that report transcriptional activity in vivo at a single-cell level with ~1-h temporal resolution can circumvent this problem. Here we describe the use of circadian clock reporter strains of Drosophila melanogaster, ClockPER and ClockTIM, to track clock transcriptional activity using the intestine as a tissue of interest. These methods may be extended to other tissues in the body.
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Affiliation(s)
- Kathyani Parasram
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | - Daniela Bachetti
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada
| | | | - Phillip Karpowicz
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, Canada.
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Intravital imaging strategy FlyVAB reveals the dependence of Drosophila enteroblast differentiation on the local physiology. Commun Biol 2021; 4:1223. [PMID: 34697396 PMCID: PMC8546075 DOI: 10.1038/s42003-021-02757-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 10/06/2021] [Indexed: 02/05/2023] Open
Abstract
Aging or injury in Drosophila intestine promotes intestinal stem cell (ISC) proliferation and enteroblast (EB) differentiation. However, the manner the local physiology couples with dynamic EB differentiation assessed by traditional lineage tracing method is still vague. Therefore, we developed a 3D-printed platform “FlyVAB” for intravital imaging strategy that enables the visualization of the Drosophila posterior midgut at a single cell level across the ventral abdomen cuticle. Using ISCs in young and healthy midgut and enteroendocrine cells in age-associated hyperplastic midgut as reference coordinates, we traced ISC-EB-enterocyte lineages with Notch signaling reporter for multiple days. Our results reveal a “differentiation-poised” EB status correlated with slow ISC divisions and a “differentiation-activated” EB status correlated with ISC hyperplasia and rapid EB to enterocyte differentiation. Our FlyVAB imaging strategy opens the door to long-time intravital imaging of intestinal epithelium. Tang et. al. demonstrate a 3Dprinted platform, FlyVAB, for intravital imaging and visualization of the Drosophila posterior midgut at a single-cell level. This method enables tracking of the stem cell lineage in the midgut of the flies constantly for up to 10 days.
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Bacillus thuringiensis Spores and Cry3A Toxins Act Synergistically to Expedite Colorado Potato Beetle Mortality. Toxins (Basel) 2021; 13:toxins13110746. [PMID: 34822531 PMCID: PMC8624055 DOI: 10.3390/toxins13110746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/06/2021] [Accepted: 10/16/2021] [Indexed: 11/17/2022] Open
Abstract
The insect integument (exoskeleton) is an effective physiochemical barrier that limits disease-causing agents to a few portals of entry, including the gastrointestinal and reproductive tracts. The bacterial biopesticide Bacillus thuringiensis (Bt) enters the insect host via the mouth and must thwart gut-based defences to make its way into the body cavity (haemocoel) and establish infection. We sought to uncover the main antibacterial defences of the midgut and the pathophysiological features of Bt in a notable insect pest, the Colorado potato beetle Leptinotarsa decemlineata (CPB). Exposing the beetles to both Bt spores and their Cry3A toxins (crystalline δ-endotoxins) via oral inoculation led to higher mortality levels when compared to either spores or Cry3A toxins alone. Within 12 h post-exposure, Cry3A toxins caused a 1.5-fold increase in the levels of reactive oxygen species (ROS) and malondialdehyde (lipid peroxidation) within the midgut - key indicators of tissue damage. When Cry3A toxins are combined with spores, gross redox imbalance and 'oxidation stress' is apparent in beetle larvae. The insect detoxification system is activated when Bt spores and Cry3A toxins are administered alone or in combination to mitigate toxicosis, in addition to elevated mRNA levels of candidate defence genes (pattern-recognition receptor, stress-regulation, serine proteases, and prosaposin-like protein). The presence of bacterial spores and/or Cry3A toxins coincides with subtle changes in microbial community composition of the midgut, such as decreased Pseudomonas abundance at 48 h post inoculation. Both Bt spores and Cry3A toxins have negative impacts on larval health, and when combined, likely cause metabolic derangement, due to multiple tissue targets being compromised.
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18
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Nirala NK, Li Q, Ghule PN, Chen HJ, Li R, Zhu LJ, Wang R, Rice NP, Mao J, Stein JL, Stein GS, van Wijnen AJ, Ip YT. Hinfp is a guardian of the somatic genome by repressing transposable elements. Proc Natl Acad Sci U S A 2021; 118:e2100839118. [PMID: 34620709 PMCID: PMC8521681 DOI: 10.1073/pnas.2100839118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2021] [Indexed: 12/19/2022] Open
Abstract
Germ cells possess the Piwi-interacting RNA pathway to repress transposable elements and maintain genome stability across generations. Transposable element mobilization in somatic cells does not affect future generations, but nonetheless can lead to pathological outcomes in host tissues. We show here that loss of function of the conserved zinc-finger transcription factor Hinfp causes dysregulation of many host genes and derepression of most transposable elements. There is also substantial DNA damage in somatic tissues of Drosophila after loss of Hinfp. Interference of transposable element mobilization by reverse-transcriptase inhibitors can suppress some of the DNA damage phenotypes. The key cell-autonomous target of Hinfp in this process is Histone1, which encodes linker histones essential for higher-order chromatin assembly. Transgenic expression of Hinfp or Histone1, but not Histone4 of core nucleosome, is sufficient to rescue the defects in repressing transposable elements and host genes. Loss of Hinfp enhances Ras-induced tissue growth and aging-related phenotypes. Therefore, Hinfp is a physiological regulator of Histone1-dependent silencing of most transposable elements, as well as many host genes, and serves as a venue for studying genome instability, cancer progression, neurodegeneration, and aging.
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Affiliation(s)
- Niraj K Nirala
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Qi Li
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Prachi N Ghule
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, VT 05405
- University of Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405
| | - Hsi-Ju Chen
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Rui Li
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Lihua Julie Zhu
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Ruijia Wang
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Nicholas P Rice
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Junhao Mao
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Janet L Stein
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, VT 05405
- University of Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405
| | - Gary S Stein
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, VT 05405
- University of Vermont Cancer Center, University of Vermont College of Medicine, Burlington, VT 05405
| | - Andre J van Wijnen
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905
| | - Y Tony Ip
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605;
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19
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Landis GN, Hilsabeck TAU, Bell HS, Ronnen-Oron T, Wang L, Doherty DV, Tejawinata FI, Erickson K, Vu W, Promislow DEL, Kapahi P, Tower J. Mifepristone Increases Life Span of Virgin Female Drosophila on Regular and High-fat Diet Without Reducing Food Intake. Front Genet 2021; 12:751647. [PMID: 34659367 PMCID: PMC8511958 DOI: 10.3389/fgene.2021.751647] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 09/13/2021] [Indexed: 12/14/2022] Open
Abstract
Background: The synthetic steroid mifepristone is reported to have anti-obesity and anti-diabetic effects in mammals on normal and high-fat diets (HFD). We previously reported that mifepristone blocks the negative effect on life span caused by mating in female Drosophila melanogaster. Methods: Here we asked if mifepristone could protect virgin females from the life span-shortening effect of HFD. Mifepristone was assayed for effects on life span in virgin females, in repeated assays, on regular media and on media supplemented with coconut oil (HFD). The excrement quantification (EX-Q) assay was used to measure food intake of the flies after 12 days mifepristone treatment. In addition, experiments were conducted to compare the effects of mifepristone in virgin and mated females, and to identify candidate mifepristone targets and mechanisms. Results: Mifepristone increased life span of virgin females on regular media, as well as on media supplemented with either 2.5 or 5% coconut oil. Food intake was not reduced in any assay, and was significantly increased by mifepristone in half of the assays. To ask if mifepristone might rescue virgin females from all life span-shortening stresses, the oxidative stressor paraquat was tested, and mifepristone produced little to no rescue. Analysis of extant metabolomics and transcriptomics data suggested similarities between effects of mifepristone in virgin and mated females, including reduced tryptophan breakdown and similarities to dietary restriction. Bioinformatics analysis identified candidate mifepristone targets, including transcription factors Paired and Extra-extra. In addition to shortening life span, mating also causes midgut hypertrophy and activation of the lipid metabolism regulatory factor SREBP. Mifepristone blocked the increase in midgut size caused by mating, but did not detectably affect midgut size in virgins. Finally, mating increased activity of a SREBP reporter in abdominal tissues, as expected, but reporter activity was not detectably reduced by mifepristone in either mated or virgin females. Conclusion: Mifepristone increases life span of virgin females on regular and HFD without reducing food intake. Metabolomics and transcriptomics analyses suggest some similar effects of mifepristone between virgin and mated females, however reduced midgut size was observed only in mated females. The results are discussed regarding possible mifepristone mechanisms and targets.
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Affiliation(s)
- Gary N. Landis
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
| | - Tyler A. U. Hilsabeck
- Buck Institute for Research on Aging, Novato, CA, United States
- Davis School of Gerontology, University of Southern California, University Park, Los Angeles, CA, United States
| | - Hans S. Bell
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
| | - Tal Ronnen-Oron
- Buck Institute for Research on Aging, Novato, CA, United States
| | - Lu Wang
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, United States
| | - Devon V. Doherty
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
| | - Felicia I. Tejawinata
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
| | - Katherine Erickson
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
| | - William Vu
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
| | - Daniel E. L. Promislow
- Department of Biology, University of Washington, Seattle, WA, United States
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, United States
| | - Pankaj Kapahi
- Buck Institute for Research on Aging, Novato, CA, United States
| | - John Tower
- Molecular and Computational Biology Section, Department of Biological Sciences, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA, United States
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20
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Neurotensin Regulates Proliferation and Stem Cell Function in the Small Intestine in a Nutrient-Dependent Manner. Cell Mol Gastroenterol Hepatol 2021; 13:501-516. [PMID: 34560309 PMCID: PMC8688554 DOI: 10.1016/j.jcmgh.2021.09.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Intestinal stem cells (ISCs) are sensitive to dietary alterations and nutrient availability. Neurotensin (NT), a gut peptide localized predominantly to the small bowel and released by fat ingestion, stimulates the growth of intestinal mucosa under basal conditions and during periods of nutrient deprivation, suggesting a possible role for NT on ISC function. METHODS Leucine-rich repeat-containing G-protein coupled receptor 5-Enhanced Green Fluorescent Protein (Lgr5-EGFP) NT wild type (Nt+/+) and Lgr5-EGFP NT knockout (Nt-/-) mice were fed ad libitum or fasted for 48 hours. Small intestine tissue and crypts were examined by gene expression analyses, fluorescence-activated cell sorting, Western blot, immunohistochemistry, and crypt-derived organoid culture. Drosophila expressing NT in midgut enteroendocrine cells were fed a standard diet or low-energy diet and esg-green fluorescent protein+ ISCs were quantified via immunofluorescence. RESULTS Loss of NT impaired crypt cell proliferation and ISC function in a manner dependent on nutrient status. Under nutrient-rich conditions, NT stimulated extracellular signal-regulated kinases 1 and 2 signaling and the expression of genes that promote cell-cycle progression, leading to crypt cell proliferation. Under conditions of nutrient depletion, NT stimulated WNT/β-catenin signaling and promoted an ISC gene signature, leading to enhanced ISC function. NT was required for the induction of WNT/β-catenin signaling and ISC-specific gene expression during nutrient depletion, and loss of NT reduced crypt cell proliferation and impaired ISC function and Lgr5 expression in the intestine during fasting. Conversely, the expression of NT in midgut enteroendocrine cells of Drosophila prevented loss of ISCs during nutrient depletion. CONCLUSIONS Collectively, our findings establish an evolutionarily conserved role for NT in ISC maintenance during nutritional stress. GSE182828.
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Abstract
The expanding field of stem cell metabolism has been supported by technical advances in metabolite profiling and novel functional analyses. While use of these methodologies has been fruitful, many challenges are posed by the intricacies of culturing stem cells in vitro, along with the distinctive scarcity of adult tissue stem cells and the complexities of their niches in vivo. This review provides an examination of the methodologies used to characterize stem cell metabolism, highlighting their utility while placing a sharper focus on their limitations and hurdles the field needs to overcome for the optimal study of stem cell metabolic networks.
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22
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Transcriptional programmes underlying cellular identity and microbial responsiveness in the intestinal epithelium. Nat Rev Gastroenterol Hepatol 2021; 18:7-23. [PMID: 33024279 PMCID: PMC7997278 DOI: 10.1038/s41575-020-00357-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/12/2020] [Indexed: 12/19/2022]
Abstract
The intestinal epithelium serves the unique and critical function of harvesting dietary nutrients, while simultaneously acting as a cellular barrier separating tissues from the luminal environment and gut microbial ecosystem. Two salient features of the intestinal epithelium enable it to perform these complex functions. First, cells within the intestinal epithelium achieve a wide range of specialized identities, including different cell types and distinct anterior-posterior patterning along the intestine. Second, intestinal epithelial cells are sensitive and responsive to the dynamic milieu of dietary nutrients, xenobiotics and microorganisms encountered in the intestinal luminal environment. These diverse identities and responsiveness of intestinal epithelial cells are achieved in part through the differential transcription of genes encoded in their shared genome. Here, we review insights from mice and other vertebrate models into the transcriptional regulatory mechanisms underlying intestinal epithelial identity and microbial responsiveness, including DNA methylation, chromatin accessibility, histone modifications and transcription factors. These studies are revealing that most transcription factors involved in intestinal epithelial identity also respond to changes in the microbiota, raising both opportunities and challenges to discern the underlying integrative transcriptional regulatory networks.
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Arthurton L, Nahotko DA, Alonso J, Wendler F, Baena‐Lopez LA. Non-apoptotic caspase activation preserves Drosophila intestinal progenitor cells in quiescence. EMBO Rep 2020; 21:e48892. [PMID: 33135280 PMCID: PMC7726796 DOI: 10.15252/embr.201948892] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/21/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022] Open
Abstract
Caspase malfunction in stem cells often precedes the appearance and progression of multiple types of cancer, including human colorectal cancer. However, the caspase-dependent regulation of intestinal stem cell properties remains poorly understood. Here, we demonstrate that Dronc, the Drosophila ortholog of caspase-9/2 in mammals, limits the number of intestinal progenitor cells and their entry into the enterocyte differentiation programme. Strikingly, these unexpected roles for Dronc are non-apoptotic and have been uncovered under experimental conditions without epithelial replenishment. Supporting the non-apoptotic nature of these functions, we show that they require the enzymatic activity of Dronc, but are largely independent of the apoptotic pathway. Alternatively, our genetic and functional data suggest that they are linked to the caspase-mediated regulation of Notch signalling. Our findings provide novel insights into the non-apoptotic, caspase-dependent modulation of stem cell properties that could improve our understanding of the origin of intestinal malignancies.
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Affiliation(s)
- Lewis Arthurton
- Sir William Dunn School of PathologyUniversity of OxfordOxfordshireUK
| | | | - Jana Alonso
- Laboratorio de Agrobiología Juan José Bravo Rodríguez (Cabildo Insular de La Palma)Unidad Técnica del IPNA‐CSICSanta Cruz de La PalmaSpain
| | - Franz Wendler
- Sir William Dunn School of PathologyUniversity of OxfordOxfordshireUK
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24
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Ariyapala IS, Holsopple JM, Popodi EM, Hartwick DG, Kahsai L, Cook KR, Sokol NS. Identification of Split-GAL4 Drivers and Enhancers That Allow Regional Cell Type Manipulations of the Drosophila melanogaster Intestine. Genetics 2020; 216:891-903. [PMID: 32988987 PMCID: PMC7768249 DOI: 10.1534/genetics.120.303625] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 09/24/2020] [Indexed: 12/30/2022] Open
Abstract
The Drosophila adult midgut is a model epithelial tissue composed of a few major cell types with distinct regional identities. One of the limitations to its analysis is the lack of tools to manipulate gene expression based on these regional identities. To overcome this obstacle, we applied the intersectional split-GAL4 system to the adult midgut and report 653 driver combinations that label cells by region and cell type. We first identified 424 split-GAL4 drivers with midgut expression from ∼7300 drivers screened, and then evaluated the expression patterns of each of these 424 when paired with three reference drivers that report activity specifically in progenitor cells, enteroendocrine cells, or enterocytes. We also evaluated a subset of the drivers expressed in progenitor cells for expression in enteroblasts using another reference driver. We show that driver combinations can define novel cell populations by identifying a driver that marks a distinct subset of enteroendocrine cells expressing genes usually associated with progenitor cells. The regional cell type patterns associated with the entire set of driver combinations are documented in a freely available website, providing information for the design of thousands of additional driver combinations to experimentally manipulate small subsets of intestinal cells. In addition, we show that intestinal enhancers identified with the split-GAL4 system can confer equivalent expression patterns on other transgenic reporters. Altogether, the resource reported here will enable more precisely targeted gene expression for studying intestinal processes, epithelial cell functions, and diseases affecting self-renewing tissues.
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Affiliation(s)
| | - Jessica M Holsopple
- Department of Biology, Indiana University, Bloomington, Indiana 47405
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Ellen M Popodi
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Dalton G Hartwick
- Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Lily Kahsai
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Kevin R Cook
- Bloomington Drosophila Stock Center, Department of Biology, Indiana University, Bloomington, Indiana 47405
| | - Nicholas S Sokol
- Department of Biology, Indiana University, Bloomington, Indiana 47405
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25
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Wiggans M, Pearson BJ. One stem cell program to rule them all? FEBS J 2020; 288:3394-3406. [PMID: 33063917 DOI: 10.1111/febs.15598] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/17/2020] [Accepted: 10/12/2020] [Indexed: 12/23/2022]
Abstract
Many species of animals have stem cells that they maintain throughout their lives, which suggests that stem cells are an ancestral feature of all animals. From this, we take the viewpoint that cells with the biological properties of 'stemness'-self-renewal and multipotency-may share ancestral genetic circuitry. However, in practice is it very difficult to identify and compare stemness gene signatures across diverse animals and large evolutionary distances? First, it is critical to experimentally demonstrate self-renewal and potency. Second, genomic methods must be used to determine specific gene expression in stem cell types compared with non-stem cell types to determine stem cell gene enrichment. Third, gene homology must be mapped between diverse animals across large evolutionary distances. Finally, conserved genes that fulfill these criteria must be tested for role in stem cell function. It is our viewpoint that by comparing stem cell-specific gene signatures across evolution, ancestral programs of stemness can be uncovered, and ultimately, the dysregulation of stemness programs drives the state of cancer stem cells.
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Affiliation(s)
- Mallory Wiggans
- Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, ON, Canada
| | - Bret J Pearson
- Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, Canada.,Department of Molecular Genetics, University of Toronto, ON, Canada.,Ontario Institute for Cancer Research, Toronto, ON, Canada
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26
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Funk MC, Zhou J, Boutros M. Ageing, metabolism and the intestine. EMBO Rep 2020; 21:e50047. [PMID: 32567155 PMCID: PMC7332987 DOI: 10.15252/embr.202050047] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 04/18/2020] [Accepted: 05/29/2020] [Indexed: 12/14/2022] Open
Abstract
The intestinal epithelium serves as a dynamic barrier to the environment and integrates a variety of signals, including those from metabolites, commensal microbiota, immune responses and stressors upon ageing. The intestine is constantly challenged and requires a high renewal rate to replace damaged cells in order to maintain its barrier function. Essential for its renewal capacity are intestinal stem cells, which constantly give rise to progenitor cells that differentiate into the multiple cell types present in the epithelium. Here, we review the current state of research of how metabolism and ageing control intestinal stem cell function and epithelial homeostasis. We focus on recent insights gained from model organisms that indicate how changes in metabolic signalling during ageing are a major driver for the loss of stem cell plasticity and epithelial homeostasis, ultimately affecting the resilience of an organism and limiting its lifespan. We compare findings made in mouse and Drosophila and discuss differences and commonalities in the underlying signalling pathways and mechanisms in the context of ageing.
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Affiliation(s)
- Maja C Funk
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ), Heidelberg University, Heidelberg, Germany
| | - Jun Zhou
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ), Heidelberg University, Heidelberg, Germany
| | - Michael Boutros
- Division Signaling and Functional Genomics, German Cancer Research Center (DKFZ), Heidelberg University, Heidelberg, Germany
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27
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The Snakeskin-Mesh Complex of Smooth Septate Junction Restricts Yorkie to Regulate Intestinal Homeostasis in Drosophila. Stem Cell Reports 2020; 14:828-844. [PMID: 32330445 PMCID: PMC7220990 DOI: 10.1016/j.stemcr.2020.03.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/27/2022] Open
Abstract
Tight junctions in mammals and septate junctions in insects are essential for epithelial integrity. We show here that, in the Drosophila intestine, smooth septate junction proteins provide barrier and signaling functions. During an RNAi screen for genes that regulate adult midgut tissue growth, we found that loss of two smooth septate junction components, Snakeskin and Mesh, caused a hyperproliferation phenotype. By examining epitope-tagged endogenous Snakeskin and Mesh, we demonstrate that the two proteins are present in the cytoplasm of differentiating enteroblasts and in cytoplasm and septate junctions of mature enterocytes. In both enteroblasts and enterocytes, loss of Snakeskin and Mesh causes Yorkie-dependent expression of the JAK-STAT pathway ligand Upd3, which in turn promotes proliferation of intestinal stem cells. Snakeskin and Mesh form a complex with each other, with other septate junction proteins and with Yorkie. Therefore, the Snakeskin-Mesh complex has both barrier and signaling function to maintain stem cell-mediated tissue homeostasis. Snakeskin and Mesh are septate junction proteins essential for intestinal homeostasis Snakeskin and Mesh act in enteroblasts and enterocytes to regulate stem cell division Snakeskin and Mesh form a complex with and restrict the activity of Yorkie Loss of Snakeskin and Mesh allows Yorkie to promote Upd3 expression and growth
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28
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Forsthoefel DJ, Cejda NI, Khan UW, Newmark PA. Cell-type diversity and regionalized gene expression in the planarian intestine. eLife 2020; 9:e52613. [PMID: 32240093 PMCID: PMC7117911 DOI: 10.7554/elife.52613] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 03/06/2020] [Indexed: 12/17/2022] Open
Abstract
Proper function and repair of the digestive system are vital to most animals. Deciphering the mechanisms involved in these processes requires an atlas of gene expression and cell types. Here, we applied laser-capture microdissection (LCM) and RNA-seq to characterize the intestinal transcriptome of Schmidtea mediterranea, a planarian flatworm that can regenerate all organs, including the gut. We identified hundreds of genes with intestinal expression undetected by previous approaches. Systematic analyses revealed extensive conservation of digestive physiology and cell types with other animals, including humans. Furthermore, spatial LCM enabled us to uncover previously unappreciated regionalization of gene expression in the planarian intestine along the medio-lateral axis, especially among intestinal goblet cells. Finally, we identified two intestine-enriched transcription factors that specifically regulate regeneration (hedgehog signaling effector gli-1) or maintenance (RREB2) of goblet cells. Altogether, this work provides resources for further investigation of mechanisms involved in gastrointestinal function, repair and regeneration.
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Affiliation(s)
- David J Forsthoefel
- Genes and Human Disease Research Program, Oklahoma Medical Research FoundationOklahoma CityUnited States
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Nicholas I Cejda
- Genes and Human Disease Research Program, Oklahoma Medical Research FoundationOklahoma CityUnited States
| | - Umair W Khan
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Phillip A Newmark
- Howard Hughes Medical Institute, Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
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29
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Okkelman IA, Neto N, Papkovsky DB, Monaghan MG, Dmitriev RI. A deeper understanding of intestinal organoid metabolism revealed by combining fluorescence lifetime imaging microscopy (FLIM) and extracellular flux analyses. Redox Biol 2020; 30:101420. [PMID: 31935648 PMCID: PMC6957829 DOI: 10.1016/j.redox.2019.101420] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/13/2019] [Accepted: 12/29/2019] [Indexed: 12/21/2022] Open
Abstract
Stem cells and the niche in which they reside feature a complex microenvironment with tightly regulated homeostasis, cell-cell interactions and dynamic regulation of metabolism. A significant number of organoid models has been described over the last decade, yet few methodologies can enable single cell level resolution analysis of the stem cell niche metabolic demands, in real-time and without perturbing integrity. Here, we studied the redox metabolism of Lgr5-GFP intestinal organoids by two emerging microscopy approaches based on luminescence lifetime measurement - fluorescence-based FLIM for NAD(P)H, and phosphorescence-based PLIM for real-time oxygenation. We found that exposure of stem (Lgr5-GFP) and differentiated (no GFP) cells to high and low glucose concentrations resulted in measurable shifts in oxygenation and redox status. NAD(P)H-FLIM and O2-PLIM both indicated that at high 'basal' glucose conditions, Lgr5-GFP cells had lower activity of oxidative phosphorylation when compared with cells lacking Lgr5. However, when exposed to low (0.5 mM) glucose, stem cells utilized oxidative metabolism more dynamically than non-stem cells. The high heterogeneity of complex 3D architecture and energy production pathways of Lgr5-GFP organoids were also confirmed by the extracellular flux (XF) analysis. Our data reveals that combined analysis of NAD(P)H-FLIM and organoid oxygenation by PLIM represents promising approach for studying stem cell niche metabolism in a live readout.
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Affiliation(s)
- Irina A Okkelman
- Laboratory of Biophysics and Bioanalysis, ABCRF, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, T12 K8AF, Ireland
| | - Nuno Neto
- Department of Mechanical and Manufacturing Engineering, Trinity College Dublin, Ireland; Trinity Centre for Biomedical Engineering, Trinity College Dublin, Ireland
| | - Dmitri B Papkovsky
- Laboratory of Biophysics and Bioanalysis, ABCRF, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, T12 K8AF, Ireland
| | - Michael G Monaghan
- Department of Mechanical and Manufacturing Engineering, Trinity College Dublin, Ireland; Trinity Centre for Biomedical Engineering, Trinity College Dublin, Ireland; Advanced Materials and BioEngineering Research (AMBER) Centre at Trinity College Dublin and Royal College of Surgeons in Ireland, Dublin, Ireland.
| | - Ruslan I Dmitriev
- Laboratory of Biophysics and Bioanalysis, ABCRF, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, T12 K8AF, Ireland; Institute for Regenerative Medicine, I.M. Sechenov First Moscow State University, Moscow, Russian Federation.
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30
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Xi J, Cai J, Cheng Y, Fu Y, Wei W, Zhang Z, Zhuang Z, Hao Y, Lilly MA, Wei Y. The TORC1 inhibitor Nprl2 protects age-related digestive function in Drosophila. Aging (Albany NY) 2019; 11:9811-9828. [PMID: 31712450 PMCID: PMC6874466 DOI: 10.18632/aging.102428] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 10/28/2019] [Indexed: 01/23/2023]
Abstract
Aging and age-related diseases occur in almost all organisms. Recently, it was discovered that the inhibition of target of rapamycin complex 1 (TORC1), a conserved complex that mediates nutrient status and cell metabolism, can extend an individual’s lifespan and inhibit age-related diseases in many model organisms. However, the mechanism whereby TORC1 affects aging remains elusive. Here, we use a loss-of-function mutation in nprl2, a component of GATOR1 that mediates amino acid levels and inhibits TORC1 activity, to investigate the effect of increased TORC1 activity on the occurrence of age-related digestive dysfunction in Drosophila. We found that the nprl2 mutation decreased Drosophila lifespan. Furthermore, the nprl2 mutant had a distended crop, with food accumulation at an early age. Interestingly, the inappropriate food distribution and digestion along with decreased crop contraction in nprl2 mutant can be rescued by decreasing TORC1 activity. In addition, nprl2-mutant flies exhibited age-related phenotypes in the midgut, including short gut length, a high rate of intestinal stem cell proliferation, and metabolic dysfunction, which could be rescued by inhibiting TORC1 activity. Our findings showed that the gastrointestinal tract aging process is accelerated in nprl2-mutant flies, owing to high TORC1 activity, which suggested that TORC1 promotes digestive tract senescence.
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Affiliation(s)
- Junmeng Xi
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Institute of Reproduction and Metabolism, Yangzhou University, Yangzhou, China
| | - Jiadong Cai
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Institute of Reproduction and Metabolism, Yangzhou University, Yangzhou, China
| | - Yang Cheng
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Yuanyuan Fu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Wanhong Wei
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China
| | - Zhenbo Zhang
- Reproductive Medicine Center, Department of Obstetrics and Gynecology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ziheng Zhuang
- School of Pharmaceutical Engineering and Life Sciences, Changzhou University, Changzhou, China
| | - Yue Hao
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Beijing, China
| | - Mary A Lilly
- Cell Biology and Neurobiology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Youheng Wei
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China.,Institute of Reproduction and Metabolism, Yangzhou University, Yangzhou, China
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31
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Zhu M, Qin YC, Gao CQ, Yan HC, Li XG, Wang XQ. Extracellular Glutamate-Induced mTORC1 Activation via the IR/IRS/PI3K/Akt Pathway Enhances the Expansion of Porcine Intestinal Stem Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9510-9521. [PMID: 31382738 DOI: 10.1021/acs.jafc.9b03626] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Glutamate (Glu) is a critical nutritional regulator of intestinal epithelial homeostasis. In addition, intestinal stem cells (ISCs) at crypt bases are known to play important roles in maintaining the renewal and homeostasis of the intestinal epithelium, and the aspects of communication between Glu and ISCs are still unknown. Here, we identify Glu and mammalian target of rapamycin complex 1 (mTORC1) as essential regulators of ISC expansion. The results showed that extracellular Glu promoted ISC expansion, indicated by increased intestinal organoid forming efficiency and budding efficiency as well as cell proliferation marker Ki67 immunofluorescence and differentiation marker Keratin 20 (KRT20) expression. Moreover, the insulin receptor (IR) mediating phosphorylation of the insulin receptor substrate (IRS) and downstream signaling phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway was involved in this response in ISCs. As expected, Glu-induced mTORC1 signaling activation was observed in the intestinal porcine enterocyte cell line (IPEC-J2), and Glu activated the PI3K/Akt/mTORC1 pathway. Accordingly, PI3K inhibition partially suppressed Glu-induced mTORC1 activation. In addition, Glu increased the phosphorylation levels of IR and IRS, and inhibiting IR downregulated the IRS/PI3K/Akt pathway. Collectively, our findings first indicate that extracellular Glu activates mTORC1 via the IR/IRS/PI3K/Akt pathway and stimulates ISC expansion, providing a new perspective for regulating the growth and health of the intestinal epithelium.
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Affiliation(s)
- Min Zhu
- College of Animal Science , South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry , Guangzhou 510642 , China
| | - Ying-Chao Qin
- College of Animal Science , South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry , Guangzhou 510642 , China
| | - Chun-Qi Gao
- College of Animal Science , South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry , Guangzhou 510642 , China
| | - Hui-Chao Yan
- College of Animal Science , South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry , Guangzhou 510642 , China
| | - Xiang-Guang Li
- Department of Pharmaceutical Engineering, School of Biomedical and Pharmaceutical Sciences , Guangdong University of Technology , Guangzhou 510006 , China
| | - Xiu-Qi Wang
- College of Animal Science , South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry , Guangzhou 510642 , China
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