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All Publications


  • Basal stem cell progeny establish their apical surface in a junctional niche during turnover of an adult barrier epithelium. Nature cell biology Galenza, A., Moreno-Roman, P., Su, Y. H., Acosta-Alvarez, L., Debec, A., Guichet, A., Knapp, J. M., Kizilyaprak, C., Humbel, B. M., Kolotuev, I., O'Brien, L. E. 2023

    Abstract

    Barrier epithelial organs face the constant challenge of sealing the interior body from the external environment while simultaneously replacing the cells that contact this environment. New replacement cells-the progeny of basal stem cells-are born without barrier-forming structures such as a specialized apical membrane and occluding junctions. Here, we investigate how new progeny acquire barrier structures as they integrate into the intestinal epithelium of adult Drosophila. We find they gestate their future apical membrane in a sublumenal niche created by a transitional occluding junction that envelops the differentiating cell and enables it to form a deep, microvilli-lined apical pit. The transitional junction seals the pit from the intestinal lumen until differentiation-driven, basal-to-apical remodelling of the niche opens the pit and integrates the now-mature cell into the barrier. By coordinating junctional remodelling with terminal differentiation, stem cell progeny integrate into a functional, adult epithelium without jeopardizing barrier integrity.

    View details for DOI 10.1038/s41556-023-01116-w

    View details for PubMedID 36997641

    View details for PubMedCentralID 5742542

  • Fly Cell Atlas: A single-nucleus transcriptomic atlas of the adult fruit fly. Science (New York, N.Y.) Li, H., Janssens, J., De Waegeneer, M., Kolluru, S. S., Davie, K., Gardeux, V., Saelens, W., David, F. P., Brbic, M., Spanier, K., Leskovec, J., McLaughlin, C. N., Xie, Q., Jones, R. C., Brueckner, K., Shim, J., Tattikota, S. G., Schnorrer, F., Rust, K., Nystul, T. G., Carvalho-Santos, Z., Ribeiro, C., Pal, S., Mahadevaraju, S., Przytycka, T. M., Allen, A. M., Goodwin, S. F., Berry, C. W., Fuller, M. T., White-Cooper, H., Matunis, E. L., DiNardo, S., Galenza, A., O'Brien, L. E., Dow, J. A., FCA Consortium, Jasper, H., Oliver, B., Perrimon, N., Deplancke, B., Quake, S. R., Luo, L., Aerts, S., Agarwal, D., Ahmed-Braimah, Y., Arbeitman, M., Ariss, M. M., Augsburger, J., Ayush, K., Baker, C. C., Banisch, T., Birker, K., Bodmer, R., Bolival, B., Brantley, S. E., Brill, J. A., Brown, N. C., Buehner, N. A., Cai, X. T., Cardoso-Figueiredo, R., Casares, F., Chang, A., Clandinin, T. R., Crasta, S., Desplan, C., Detweiler, A. M., Dhakan, D. B., Dona, E., Engert, S., Floc'hlay, S., George, N., Gonzalez-Segarra, A. J., Groves, A. K., Gumbin, S., Guo, Y., Harris, D. E., Heifetz, Y., Holtz, S. L., Horns, F., Hudry, B., Hung, R., Jan, Y. N., Jaszczak, J. S., Jefferis, G. S., Karkanias, J., Karr, T. L., Katheder, N. S., Kezos, J., Kim, A. A., Kim, S. K., Kockel, L., Konstantinides, N., Kornberg, T. B., Krause, H. M., Labott, A. T., Laturney, M., Lehmann, R., Leinwand, S., Li, J., Li, J. S., Li, K., Li, K., Li, L., Li, T., Litovchenko, M., Liu, H., Liu, Y., Lu, T., Manning, J., Mase, A., Matera-Vatnick, M., Matias, N. R., McDonough-Goldstein, C. E., McGeever, A., McLachlan, A. D., Moreno-Roman, P., Neff, N., Neville, M., Ngo, S., Nielsen, T., O'Brien, C. E., Osumi-Sutherland, D., Ozel, M. N., Papatheodorou, I., Petkovic, M., Pilgrim, C., Pisco, A. O., Reisenman, C., Sanders, E. N., Dos Santos, G., Scott, K., Sherlekar, A., Shiu, P., Sims, D., Sit, R. V., Slaidina, M., Smith, H. E., Sterne, G., Su, Y., Sutton, D., Tamayo, M., Tan, M., Tastekin, I., Treiber, C., Vacek, D., Vogler, G., Waddell, S., Wang, W., Wilson, R. I., Wolfner, M. F., Wong, Y. E., Xie, A., Xu, J., Yamamoto, S., Yan, J., Yao, Z., Yoda, K., Zhu, R., Zinzen, R. P. 2022; 375 (6584): eabk2432

    Abstract

    For more than 100 years, the fruit fly Drosophila melanogaster has been one of the most studied model organisms. Here, we present a single-cell atlas of the adult fly, Tabula Drosophilae, that includes 580,000 nuclei from 15 individually dissected sexed tissues as well as the entire head and body, annotated to >250 distinct cell types. We provide an in-depth analysis of cell type-related gene signatures and transcription factor markers, as well as sexual dimorphism, across the whole animal. Analysis of common cell types between tissues, such as blood and muscle cells, reveals rare cell types and tissue-specific subtypes. This atlas provides a valuable resource for the Drosophila community and serves as a reference to study genetic perturbations and disease models at single-cell resolution.

    View details for DOI 10.1126/science.abk2432

    View details for PubMedID 35239393

  • Differential effects of commensal bacteria on progenitor cell adhesion, division symmetry and tumorigenesis in the <i>Drosophila</i> intestine DEVELOPMENT Ferguson, M., Petkau, K., Shin, M., Galenza, A., Fast, D., Foley, E. 2021; 148 (5)

    Abstract

    Microbial factors influence homeostatic and oncogenic growth in the intestinal epithelium. However, we know little about immediate effects of commensal bacteria on stem cell division programs. In this study, we examined the effects of commensal Lactobacillus species on homeostatic and tumorigenic stem cell proliferation in the female Drosophila intestine. We identified Lactobacillus brevis as a potent stimulator of stem cell divisions. In a wild-type midgut, L.brevis activates growth regulatory pathways that drive stem cell divisions. In a Notch-deficient background, L.brevis-mediated proliferation causes rapid expansion of mutant progenitors, leading to accumulation of large, multi-layered tumors throughout the midgut. Mechanistically, we showed that L.brevis disrupts expression and subcellular distribution of progenitor cell integrins, supporting symmetric divisions that expand intestinal stem cell populations. Collectively, our data emphasize the impact of commensal microbes on division and maintenance of the intestinal progenitor compartment.

    View details for DOI 10.1242/dev.186106

    View details for Web of Science ID 000629250600003

    View details for PubMedID 33593820

  • A glucose-supplemented diet enhances gut barrier integrity in Drosophila. Biology open Galenza, A., Foley, E. 2021

    Abstract

    Dietary intervention has received considerable attention as an approach to extend lifespan and improve aging. However, questions remain regarding optimal dietary regimes and underlying mechanisms of lifespan extension. Here, we asked how an increase of glucose in a chemically defined diet extends the lifespan of adult Drosophila We showed that glucose-dependent lifespan extension is not a result of diminished caloric intake, or changes to systemic insulin activity, two commonly studied mechanisms of lifespan extension. Instead, we found that flies raised on glucose-supplemented food increased the expression of cell adhesion genes, delaying age-dependent loss of intestinal barrier integrity. Furthermore, we showed that chemical disruption of the gut barrier negated the lifespan extension associated with glucose-treatment, suggesting that glucose-supplemented food prolongs adult viability by enhancing the intestinal barrier. We believe our data contribute to understanding intestinal homeostasis, and may assist efforts to develop preventative measures that limit effects of aging on health.

    View details for DOI 10.1242/bio.056515

    View details for PubMedID 33579694

  • <i>Vibrio cholerae</i>-Symbiont Interactions Inhibit Intestinal Repair in <i>Drosophila</i> CELL REPORTS Fast, D., Petkau, K., Ferguson, M., Shin, M., Galenza, A., Kostiuk, B., Pukatzki, S., Foley, E. 2020; 30 (4): 1088-+

    Abstract

    Pathogen-mediated damage to the intestinal epithelium activates compensatory growth and differentiation repair programs in progenitor cells. Accelerated progenitor growth replenishes damaged tissue and maintains barrier integrity. Despite the importance of epithelial renewal to intestinal homeostasis, we know little about the effects of pathogen-commensal interactions on progenitor growth. We find that the enteric pathogen Vibrio cholerae blocks critical growth and differentiation pathways in Drosophila progenitors, despite extensive damage to epithelial tissue. We show that the inhibition of epithelial repair requires interactions between the Vibrio cholerae type six secretion system and a community of common symbiotic bacteria, as elimination of the gut microbiome is sufficient to restore homeostatic growth in infected intestines. This work highlights the importance of pathogen-symbiont interactions for intestinal immune responses and outlines the impact of the type six secretion system on pathogenesis.

    View details for DOI 10.1016/j.celrep.2019.12.094

    View details for Web of Science ID 000509775700013

    View details for PubMedID 31995751

    View details for PubMedCentralID PMC9684019

  • The Immune Deficiency Pathway Regulates Metabolic Homeostasis in <i>Drosophila</i> JOURNAL OF IMMUNOLOGY Davoodi, S., Galenza, A., Panteluk, A., Deshpande, R., Ferguson, M., Grewa, S., Foley, E. 2019; 202 (9): 2747-2759

    Abstract

    Immune and metabolic pathways collectively influence host responses to microbial invaders, and mutations in one pathway frequently disrupt activity in another. We used the Drosophila melanogaster model to characterize metabolic homeostasis in flies with modified immune deficiency (IMD) pathway activity. The IMD pathway is very similar to the mammalian TNF-α pathway, a key regulator of vertebrate immunity and metabolism. We found that persistent activation of IMD resulted in hyperglycemia, depleted fat reserves, and developmental delays, implicating IMD in metabolic regulation. Consistent with this hypothesis, we found that imd mutants weigh more, are hyperlipidemic, and have impaired glucose tolerance. To test the importance of metabolic regulation for host responses to bacterial infection, we challenged insulin pathway mutants with lethal doses of several Drosophila pathogens. We found that loss-of-function mutations in the insulin pathway impacted host responses to infection in a manner that depends on the route of infection and the identity of the infectious microbe. Combined, our results support a role for coordinated regulation of immune and metabolic pathways in host containment of microbial invaders.

    View details for DOI 10.4049/jimmunol.1801632

    View details for Web of Science ID 000465364300024

    View details for PubMedID 30902902

  • Immunometabolism: Insights from the <i>Drosophila</i> model DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY Galenza, A., Foley, E. 2019; 94: 22-34

    Abstract

    Multicellular organisms inhabit an environment that includes a mix of essential nutrients and large numbers of potentially harmful microbes. Germline-encoded receptors scan the environment for microbe associated molecular patterns, and, upon engagement, activate powerful defenses to protect the host from infection. At the same time, digestive enzymes and transporter molecules sieve through ingested material for building blocks and energy sources necessary for survival, growth, and reproduction. We tend to view immune responses as a potent array of destructive forces that overwhelm potentially harmful agents. In contrast, we view metabolic processes as essential, constructive elements in the maintenance and propagation of life. However, there is considerable evidence of functional overlap between the two processes, and disruptions to one frequently modify outputs of the other. Studies of immunometabolism, or interactions between immunity and metabolism, have increased in prominence with the discovery of inflammatory components to metabolic diseases such as type two diabetes. In this review, we will focus on contributions of studies with the fruit fly, Drosophila melanogaster, to our understanding of immunometabolism. Drosophila is widely used to study immune signaling, and to understand the regulation of metabolism in vivo, and this insect has considerable potential as a tool to build our understanding of the molecular and cellular bridges that connect immune and metabolic pathways.

    View details for DOI 10.1016/j.dci.2019.01.011

    View details for Web of Science ID 000460826100004

    View details for PubMedID 30684503

  • Glucose modulates <i>Drosophila</i> longevity and immunity independent of the microbiota BIOLOGY OPEN Galenza, A., Hutchinson, J., Campbell, S. D., Hazes, B., Foley, E. 2016; 5 (2): 165-173

    Abstract

    The acquisition of nutrients is essential for maintenance of metabolic processes in all organisms. Nutritional imbalance contributes to myriad metabolic disorders that include malnutrition, diabetes and even cancer. Recently, the importance of macronutrient ratio of food has emerged as a critical factor to determine health outcomes. Here we show that individual modifications to a completely defined diet markedly impact multiple aspects of organism wellbeing in Drosophila melanogaster. Through a longitudinal survey of several diets we demonstrate that increased levels of dietary glucose significantly improve longevity and immunity in adult Drosophila. Our metagenomic studies show that relative macronutrient levels not only influence the host, but also have a profound impact on microbiota composition. However, we found that elevated dietary glucose extended the lifespan of adult flies even when raised in a germ-free environment. Furthermore, when challenged with a chronic enteric infection, flies fed a diet with added glucose had increased survival times even in the absence of an intact microbiota. Thus, in contrast to known links between the microbiota and animal health, our findings uncover a novel microbiota-independent response to diet that impacts host wellbeing. As dietary responses are highly conserved in animals, we believe our results offer a general understanding of the association between glucose metabolism and animal health.

    View details for DOI 10.1242/bio.015016

    View details for Web of Science ID 000370240300010

    View details for PubMedID 26794610

    View details for PubMedCentralID PMC4823985