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McPherson WK, Van Gorder EE, Hilovsky DL, Jamali LA, Keliinui CN, Suzawa M, Bland ML. Synchronizing Drosophila larvae with the salivary gland reporter Sgs3-GFP for discovery of phenotypes in the late third instar stage. Dev Biol 2024; 512:35-43. [PMID: 38710381 DOI: 10.1016/j.ydbio.2024.05.002] [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: 01/26/2024] [Revised: 04/23/2024] [Accepted: 05/03/2024] [Indexed: 05/08/2024]
Abstract
The larval stage of the Drosophila melanogaster life cycle is characterized by rapid growth and nutrient storage that occur over three instar stages separated by molts. In the third instar, the steroid hormone ecdysone drives key developmental processes and behaviors that occur in a temporally-controlled sequence and prepare the animal to undergo metamorphosis. Accurately staging Drosophila larvae within the final third instar is critical due to the rapid developmental progress at this stage, but it is challenging because the rate of development varies widely across a population of animals even if eggs are laid within a short period of time. Moreover, many methods to stage third instar larvae are cumbersome, and inherent variability in the rate of development confounds some of these approaches. Here we demonstrate the usefulness of the Sgs3-GFP transgene, a fusion of the Salivary gland secretion 3 (Sgs3) and GFP proteins, for staging third instar larvae. Sgs3-GFP is expressed in the salivary glands in an ecdysone-dependent manner from the midpoint of the third instar, and its expression pattern changes reproducibly as larvae progress through the third instar. We show that Sgs3-GFP can easily be incorporated into experiments, that it allows collection of developmentally-equivalent individuals from a mixed population of larvae, and that its use enables precise assessment of changing levels of hormones, metabolites, and gene expression during the second half of the third instar.
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Affiliation(s)
- W Kyle McPherson
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA
| | - Elizabeth E Van Gorder
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA
| | - Dalton L Hilovsky
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA
| | - Leila A Jamali
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA
| | - Cami N Keliinui
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA
| | - Miyuki Suzawa
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA
| | - Michelle L Bland
- Department of Pharmacology, University of Virginia, Charlottesville, VA, 22908-0875, USA.
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Liu F, Cui Y, Lu H, Chen X, Li Q, Ye Z, Chen W, Zhu S. Myofilaments promote wing expansion and maintain genitalia morphology in the American cockroach, Periplaneta americana. INSECT MOLECULAR BIOLOGY 2023; 32:46-55. [PMID: 36214335 DOI: 10.1111/imb.12812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Insects are the most widely distributed and successful animals on the planet. A large number of insects are capable of flight with functional wings. Wing expansion is an important process for insects to achieve functional wings after eclosion and healthy genital morphology is crucial for adult reproduction. Myofilaments are functional units that constitute sarcomeres and trigger muscle contraction. Here, we identified four myofilament proteins, including Myosin, Paramyosin, Tropomyosin and Troponin T, from the wing pads of nymphs in the American cockroach, Periplaneta americana. RNAi-mediated knockdown of Myosin, Paramyosin, Tropomyosin and Troponin T in the early stage of final instar nymphs caused a severely curly wing phenotype in the imaginal moult, especially in the Paramyosin and Troponin T knockdown groups, indicating that these myofilament proteins are involved in controlling wing expansion behaviours during the nymph-adult transition. In addition, the knockdown resulted in abnormal external genitalia, caused ovulation failure, and affected male accessory gland development. Interestingly, the expression of myofilament genes was induced by methoprene, a juvenile hormone (JH) analogue, and decreased by the depletion of the JH receptor gene Met. Altogether, we have determined that myofilament genes play an important role in promoting wing expansion and maintaining adult genitalia morphology, and their expression is induced by JH signalling. Our data reveal a novel mechanism by which wing expansion is regulated by myofilaments and the functions of myofilaments are involved in maintaining genitalia morphology.
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Affiliation(s)
- Fangfang Liu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Yingying Cui
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Huna Lu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Xiaoyi Chen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Qin Li
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Ziqi Ye
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Wanyi Chen
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
| | - Shiming Zhu
- Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou, People's Republic of China
- Guangmeiyuan R&D Center, Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, South China Normal University, Meizhou, People's Republic of China
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3
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NGLY1 Deficiency, a Congenital Disorder of Deglycosylation: From Disease Gene Function to Pathophysiology. Cells 2022; 11:cells11071155. [PMID: 35406718 PMCID: PMC8997433 DOI: 10.3390/cells11071155] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 02/01/2023] Open
Abstract
N-Glycanase 1 (NGLY1) is a cytosolic enzyme involved in removing N-linked glycans of misfolded N-glycoproteins and is considered to be a component of endoplasmic reticulum-associated degradation (ERAD). The 2012 identification of recessive NGLY1 mutations in a rare multisystem disorder has led to intense research efforts on the roles of NGLY1 in animal development and physiology, as well as the pathophysiology of NGLY1 deficiency. Here, we present a review of the NGLY1-deficient patient phenotypes, along with insights into the function of this gene from studies in rodent and invertebrate animal models, as well as cell culture and biochemical experiments. We will discuss critical processes affected by the loss of NGLY1, including proteasome bounce-back response, mitochondrial function and homeostasis, and bone morphogenetic protein (BMP) signaling. We will also cover the biologically relevant targets of NGLY1 and the genetic modifiers of NGLY1 deficiency phenotypes in animal models. Together, these discoveries and disease models have provided a number of avenues for preclinical testing of potential therapeutic approaches for this disease.
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4
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Shukla N, Kolthur‐Seetharam U. Drosophila Sirtuin 6 mediates developmental diet-dependent programming of adult physiology and survival. Aging Cell 2022; 21:e13576. [PMID: 35233942 PMCID: PMC8920434 DOI: 10.1111/acel.13576] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/12/2022] [Accepted: 02/06/2022] [Indexed: 11/29/2022] Open
Abstract
Organisms in the wild experience unpredictable and diverse food availability throughout their lifespan. Over-/under-nutrition during development and in adulthood is known to dictate organismal survival and fitness. Studies using model systems have also established long-term effects of developmental dietary alterations on life-history traits. However, the underlining genetic/molecular factors, which differentially couple nutrient inputs during development with fitness later in life are far less understood. Using Drosophila and loss/gain of function perturbations, our serendipitous findings demonstrate an essential role of Sirtuin 6 in regulating larval developmental kinetics, in a nutrient-dependent manner. The absence of Sirt6 affected ecdysone and insulin signalling and led to accelerated larval development. Moreover, varying dietary glucose and yeast during larval stages resulted in enhanced susceptibility to metabolic and oxidative stress in adults. We also demonstrate an evolutionarily conserved role for Sirt6 in regulating physiological homeostasis, physical activity and organismal lifespan, known only in mammals until now. Our results highlight gene-diet interactions that dictate thresholding of nutrient inputs and physiological plasticity, operative across development and adulthood. In summary, besides showing its role in invertebrate ageing, our study also identifies Sirt6 as a key factor that programs macronutrient-dependent life-history traits.
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Affiliation(s)
- Namrata Shukla
- Department of Biological Sciences Tata Institute of Fundamental Research Mumbai India
| | - Ullas Kolthur‐Seetharam
- Department of Biological Sciences Tata Institute of Fundamental Research Mumbai India
- Tata Institute of Fundamental Research‐Hyderabad (TIFR‐H) Hyderabad India
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5
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Xiao Y, Li W, Yang X, Xu P, Jin M, Yuan H, Zheng W, Soberón M, Bravo A, Wilson K, Wu K. Rapid spread of a densovirus in a major crop pest following wide-scale adoption of Bt-cotton in China. eLife 2021; 10:e66913. [PMID: 34263726 PMCID: PMC8324301 DOI: 10.7554/elife.66913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 07/13/2021] [Indexed: 12/21/2022] Open
Abstract
Bacillus thuringiensis (Bt) crops have been widely planted and the effects of Bt-crops on populations of the target and non-target insect pests have been well studied. However, the effects of Bt-crops exposure on microorganisms that interact with crop pests have not previously been quantified. Here, we use laboratory and field data to show that infection of Helicoverpa armigera with a densovirus (HaDV2) is associated with its enhanced growth and tolerance to Bt-cotton. Moreover, field monitoring showed a much higher incidence of cotton bollworm infection with HaDV2 in regions cultivated with Bt-cotton than in regions without it, with the rate of densovirus infection increasing with increasing use of Bt-cotton. RNA-seq suggested tolerance to both baculovirus and Cry1Ac were enhanced via the immune-related pathways. These findings suggest that exposure to Bt-crops has selected for beneficial interactions between the target pest and a mutualistic microorganism that enhances its performance on Bt-crops under field conditions.
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Affiliation(s)
- Yutao Xiao
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural SciencesShenzhenChina
| | - Wenjing Li
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
- Institute of Plant Protection and Soil Fertility, Hubei Academy of Agricultural SciencesWuhanChina
| | - Xianming Yang
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Pengjun Xu
- Tobacco Research Institute, Chinese Academy of Agricultural SciencesQingdaoChina
- Lancaster Environment Centre, Lancaster UniversityLancasterUnited Kingdom
| | - Minghui Jin
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural SciencesShenzhenChina
| | - He Yuan
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural SciencesShenzhenChina
| | - Weigang Zheng
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural SciencesShenzhenChina
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de MéxicoMorelosUnited States
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de MéxicoMorelosUnited States
| | - Kenneth Wilson
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural SciencesShenzhenChina
- Lancaster Environment Centre, Lancaster UniversityLancasterUnited Kingdom
| | - Kongming Wu
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
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6
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Hasygar K, Deniz O, Liu Y, Gullmets J, Hynynen R, Ruhanen H, Kokki K, Käkelä R, Hietakangas V. Coordinated control of adiposity and growth by anti-anabolic kinase ERK7. EMBO Rep 2021; 22:e49602. [PMID: 33369866 PMCID: PMC7857433 DOI: 10.15252/embr.201949602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/18/2020] [Accepted: 11/27/2020] [Indexed: 11/23/2022] Open
Abstract
Energy storage and growth are coordinated in response to nutrient status of animals. How nutrient-regulated signaling pathways control these processes in vivo remains insufficiently understood. Here, we establish an atypical MAP kinase, ERK7, as an inhibitor of adiposity and growth in Drosophila. ERK7 mutant larvae display elevated triacylglycerol (TAG) stores and accelerated growth rate, while overexpressed ERK7 is sufficient to inhibit lipid storage and growth. ERK7 expression is elevated upon fasting and ERK7 mutant larvae display impaired survival during nutrient deprivation. ERK7 acts in the fat body, the insect counterpart of liver and adipose tissue, where it controls the subcellular localization of chromatin-binding protein PWP1, a growth-promoting downstream effector of mTOR. PWP1 maintains the expression of sugarbabe, encoding a lipogenic Gli-similar family transcription factor. Both PWP1 and Sugarbabe are necessary for the increased growth and adiposity phenotypes of ERK7 loss-of-function animals. In conclusion, ERK7 is an anti-anabolic kinase that inhibits lipid storage and growth while promoting survival on fasting conditions.
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Affiliation(s)
- Kiran Hasygar
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | - Onur Deniz
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | - Ying Liu
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | - Josef Gullmets
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | - Riikka Hynynen
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | - Hanna Ruhanen
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Helsinki University Lipidomics Unit (HiLIPID)Helsinki Institute for Life Science (HiLIFE) and Biocenter FinlandHelsinkiFinland
| | - Krista Kokki
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
| | - Reijo Käkelä
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Helsinki University Lipidomics Unit (HiLIPID)Helsinki Institute for Life Science (HiLIFE) and Biocenter FinlandHelsinkiFinland
| | - Ville Hietakangas
- Molecular and Integrative Biosciences Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
- Institute of BiotechnologyUniversity of HelsinkiHelsinkiFinland
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7
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Han SY, Pandey A, Moore T, Galeone A, Duraine L, Cowan TM, Jafar-Nejad H. A conserved role for AMP-activated protein kinase in NGLY1 deficiency. PLoS Genet 2020; 16:e1009258. [PMID: 33315951 PMCID: PMC7769621 DOI: 10.1371/journal.pgen.1009258] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 12/28/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023] Open
Abstract
Mutations in human N-glycanase 1 (NGLY1) cause the first known congenital disorder of deglycosylation (CDDG). Patients with this rare disease, which is also known as NGLY1 deficiency, exhibit global developmental delay and other phenotypes including neuropathy, movement disorder, and constipation. NGLY1 is known to regulate proteasomal and mitophagy gene expression through activation of a transcription factor called "nuclear factor erythroid 2-like 1" (NFE2L1). Loss of NGLY1 has also been shown to impair energy metabolism, but the molecular basis for this phenotype and its in vivo consequences are not well understood. Using a combination of genetic studies, imaging, and biochemical assays, here we report that loss of NGLY1 in the visceral muscle of the Drosophila larval intestine results in a severe reduction in the level of AMP-activated protein kinase α (AMPKα), leading to energy metabolism defects, impaired gut peristalsis, failure to empty the gut, and animal lethality. Ngly1-/- mouse embryonic fibroblasts and NGLY1 deficiency patient fibroblasts also show reduced AMPKα levels. Moreover, pharmacological activation of AMPK signaling significantly suppressed the energy metabolism defects in these cells. Importantly, the reduced AMPKα level and impaired energy metabolism observed in NGLY1 deficiency models are not caused by the loss of NFE2L1 activity. Taken together, these observations identify reduced AMPK signaling as a conserved mediator of energy metabolism defects in NGLY1 deficiency and suggest AMPK signaling as a therapeutic target in this disease.
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Affiliation(s)
- Seung Yeop Han
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ashutosh Pandey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Tereza Moore
- Department of Pathology, Stanford University, Stanford, California, United States of America
| | - Antonio Galeone
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lita Duraine
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas, United States of America
- Jan & Dan Duncan Neurological Research Institute Center, Texas Children’s Hospital, Houston, Texas, United States of America
| | - Tina M. Cowan
- Department of Pathology, Stanford University, Stanford, California, United States of America
| | - Hamed Jafar-Nejad
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States of America
- Genetics & Genomics Graduate Program, Baylor College of Medicine, Houston, Texas, United States of America
- Development, Disease Models & Therapeutics Graduate Program, Baylor College of Medicine, Houston, Texas, United States of America
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas, United States of America
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8
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Kierdorf K, Hersperger F, Sharrock J, Vincent CM, Ustaoglu P, Dou J, Gyoergy A, Groß O, Siekhaus DE, Dionne MS. Muscle function and homeostasis require cytokine inhibition of AKT activity in Drosophila. eLife 2020; 9:e51595. [PMID: 31944178 PMCID: PMC6996930 DOI: 10.7554/elife.51595] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/10/2020] [Indexed: 12/20/2022] Open
Abstract
Unpaired ligands are secreted signals that act via a GP130-like receptor, domeless, to activate JAK/STAT signalling in Drosophila. Like many mammalian cytokines, unpaireds can be activated by infection and other stresses and can promote insulin resistance in target tissues. However, the importance of this effect in non-inflammatory physiology is unknown. Here, we identify a requirement for unpaired-JAK signalling as a metabolic regulator in healthy adult Drosophila muscle. Adult muscles show basal JAK-STAT signalling activity in the absence of any immune challenge. Plasmatocytes (Drosophila macrophages) are an important source of this tonic signal. Loss of the dome receptor on adult muscles significantly reduces lifespan and causes local and systemic metabolic pathology. These pathologies result from hyperactivation of AKT and consequent deregulation of metabolism. Thus, we identify a cytokine signal that must be received in muscle to control AKT activity and metabolic homeostasis.
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Affiliation(s)
- Katrin Kierdorf
- MRC Centre for Molecular Bacteriology and InfectionImperial College LondonLondonUnited Kingdom
- Department of Life SciencesImperial College LondonLondonUnited Kingdom
| | - Fabian Hersperger
- Institute of Neuropathology, Faculty of MedicineUniversity of FreiburgFreiburgGermany
- Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Jessica Sharrock
- MRC Centre for Molecular Bacteriology and InfectionImperial College LondonLondonUnited Kingdom
- Department of Life SciencesImperial College LondonLondonUnited Kingdom
| | - Crystal M Vincent
- MRC Centre for Molecular Bacteriology and InfectionImperial College LondonLondonUnited Kingdom
- Department of Life SciencesImperial College LondonLondonUnited Kingdom
| | - Pinar Ustaoglu
- MRC Centre for Molecular Bacteriology and InfectionImperial College LondonLondonUnited Kingdom
- Department of Life SciencesImperial College LondonLondonUnited Kingdom
| | - Jiawen Dou
- MRC Centre for Molecular Bacteriology and InfectionImperial College LondonLondonUnited Kingdom
| | - Attila Gyoergy
- Institute of Science and TechnologyKlosterneuburgAustria
| | - Olaf Groß
- Institute of Neuropathology, Faculty of MedicineUniversity of FreiburgFreiburgGermany
- Centre for Integrative Biological Signalling Studies (CIBSS)University of FreiburgFreiburgGermany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of MedicineUniversity of FreiburgFreiburgGermany
| | | | - Marc S Dionne
- MRC Centre for Molecular Bacteriology and InfectionImperial College LondonLondonUnited Kingdom
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9
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Pimsler ML, Sze S, Saenz S, Fu S, Tomberlin JK, Tarone AM. Gene expression correlates of facultative predation in the blow fly Chrysomya rufifacies (Diptera: Calliphoridae). Ecol Evol 2019; 9:8690-8701. [PMID: 31410272 PMCID: PMC6686648 DOI: 10.1002/ece3.5413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 05/26/2019] [Accepted: 05/27/2019] [Indexed: 11/17/2022] Open
Abstract
Effects of intraguild predation (IGP) on omnivores and detritivores are relatively understudied when compared to work on predator guilds. Functional genetic work in IGP is even more limited, but its application can help answer a range of questions related to ultimate and proximate causes of this behavior. Here, we integrate behavioral assays and transcriptomic analysis of facultative predation in a blow fly (Diptera: Calliphoridae) to evaluate the prevalence, effect, and correlated gene expression of facultative predation by the invasive species Chrysomya rufifacies. Field work observing donated human cadavers indicated facultative predation by C. rufifacies on the native blow fly Cochliomyia macellaria was rare under undisturbed conditions, owing in part to spatial segregation between species. Laboratory assays under conditions of starvation showed predation had a direct fitness benefit (i.e., survival) to the predator. As a genome is not available for C. rufifacies, a de novo transcriptome was developed and annotated using sequence similarity to Drosophila melanogaster. Under a variety of assembly parameters, several genes were identified as being differentially expressed between predators and nonpredators of this species, including genes involved in cell-to-cell signaling, osmotic regulation, starvation responses, and dopamine regulation. Results of this work were integrated to develop a model of the processes and genetic regulation controlling facultative predation.
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Affiliation(s)
- Meaghan L. Pimsler
- Department of EntomologyTexas A&M UniversityCollege StationTexasUSA
- Department of Biological SciencesUniversity of AlabamaTuscaloosaAlabamaUSA
| | - Sing‐Hoi Sze
- Department of Computer Science and EngineeringTexas A&M UniversityCollege StationTexasUSA
| | - Sunday Saenz
- Department of EntomologyTexas A&M UniversityCollege StationTexasUSA
- Federal Aviation AdministrationFederal Government OfficeTulsaOklahomaUSA
| | - Shuhua Fu
- Department of Biochemistry & BiophysicsTexas A&M UniversityCollege StationTexasUSA
- Department of Developmental BiologyWashington University School of Medicine in St. LouisSt. LouisMissouriUSA
| | | | - Aaron M. Tarone
- Department of EntomologyTexas A&M UniversityCollege StationTexasUSA
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10
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Emami NK, Calik A, White MB, Young M, Dalloul RA. Necrotic Enteritis in Broiler Chickens: The Role of Tight Junctions and Mucosal Immune Responses in Alleviating the Effect of the Disease. Microorganisms 2019; 7:E231. [PMID: 31370350 PMCID: PMC6723922 DOI: 10.3390/microorganisms7080231] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/14/2022] Open
Abstract
Necrotic enteritis (NE) continues to present major challenges to the poultry industry, and the etiologic agent Clostridium perfringens is the fourth leading cause of bacterially-induced food- borne illnesses in the US. This study was designed to evaluate the effects of a probiotic during naturally occurring NE. On day of hatch, 1080 Cobb 500 male broilers were randomly allocated to three groups (12 replicate pens/treatment, 30 birds/pen) including 1) negative control (NC): corn-soybean meal diet; 2) positive control (PC): NC + 20 mg virginiamycin/kg diet (0.450 kg Stafac®20/ton); and 3) NC + PrimaLac (1.36 and 0.91 kg/ton from 1-21 and 22-42 days, respectively). One day (d) post placement, all birds were challenged by a commercial live oocyst coccidia vaccine as a predisposing factor to NE. Body weight and feed intake were measured at the onset of NE (d 8) and end of each feeding phase. On d 8, small intestines of two birds/pen were examined for NE lesions, and jejunum samples from one bird were collected for mRNA gene expression analysis of tight junction proteins, cytokines, and nutrient transporters. Data were analyzed using the Jump (JMP) software and significance between treatments identified by LSD (P < 0.05). Compared to NC, supplementation of probiotic reduced d 1-42 mortality; however, PC was the only group with significantly lower mortality. Despite significantly improved feed conversion ratio (FCR) in PC and probiotic groups during d 1-42, average daily gain was only higher in PC (77.69 g/bird) compared with NC (74.99 g/bird). Furthermore, probiotic and PC groups had significantly reduced lesion scores in the duodenum and jejunum compared to NC. Expression of claudin-3 was higher, while expression of zonula occluden-2 tended (P = 0.06) to be higher in probiotic-supplemented birds compared to NC. Moreover, birds fed the probiotic diet had significantly higher expression of IL-10, IL-17, AMPK-α1, and SGLT1 mRNA compared to NC birds. The expression of PepT1 was higher for the probiotic-supplemented group compared to PC. IFN-γ expression was lower in PC compared to NC, while there was no difference between probiotic and NC. There were no differences in gene expression of sIgA, TNF-α, IL-1β, and IL-22 among treatments. Collectively, these data indicate that in a naturally occurring NE model, supplementation of a probiotic helps to improve FCR and reduce lesions, potentially due to the improvements in mRNA expression of tight junctions, cytokines, and nutrient transporters.
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Affiliation(s)
- Nima K Emami
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ali Calik
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
- Department of Animal Nutrition and Nutritional Diseases, Faculty of Veterinary Medicine, Ankara University, Ankara 06110, Turkey
| | - Mallory B White
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Mark Young
- Star-Labs/Forage Research, Inc., Clarksdale, 64430 MO, USA
| | - Rami A Dalloul
- Avian Immunobiology Laboratory, Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
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11
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Roth SW, Bitterman MD, Birnbaum MJ, Bland ML. Innate Immune Signaling in Drosophila Blocks Insulin Signaling by Uncoupling PI(3,4,5)P 3 Production and Akt Activation. Cell Rep 2019. [PMID: 29514084 PMCID: PMC5866056 DOI: 10.1016/j.celrep.2018.02.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In obese adipose tissue, Toll-like receptor signaling in macrophages leads to insulin resistance in adipocytes. Similarly, Toll signaling in the Drosophila larval fat body blocks insulin-dependent growth and nutrient storage. We find that Toll acts cell autonomously to block growth but not PI(3,4,5)P3 production in fat body cells expressing constitutively active PI3K. Fat body Toll signaling blocks whole-animal growth in rictor mutants lacking TORC2 activity, but not in larvae lacking Pdk1. Phosphorylation of Akt on the Pdk1 site, Thr342, is significantly reduced by Toll signaling, and expression of mutant AktT342D rescues cell and animal growth, nutrient storage, and viability in animals with active Toll signaling. Altogether, these data show that innate immune signaling blocks insulin signaling at a more distal level than previously appreciated, and they suggest that manipulations affecting the Pdk1 arm of the pathway may have profound effects on insulin sensitivity in inflamed tissues.
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Affiliation(s)
- Stephen W Roth
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Moshe D Bitterman
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Morris J Birnbaum
- Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michelle L Bland
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.
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12
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Morgunova GV, Klebanov AA. Age-related AMP-activated protein kinase alterations: From cellular energetics to longevity. Cell Biochem Funct 2019; 37:169-176. [PMID: 30895648 DOI: 10.1002/cbf.3384] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 02/05/2019] [Indexed: 12/18/2022]
Abstract
5' adenosine monophosphate-activated protein kinase (AMPK) is a key regulator of energy in the cell, which allows the cell/organism to survive with deficit of ATP. Since AMPK is involved in the adaptation to caloric restriction, the role of age-related changes in AMPK activity in both the aging organism and the aging cell is actively investigated in gerontology. Studies on yeast, worms, flies, rodents, and primates have demonstrated an important effect of this regulator on key signalling pathways involved in the aging process. In some cases, researchers conclude that AMPK promotes aging. However, in our opinion, in such cases, we observe a disturbance in the adaptive ability because of the prolonged cell/organism presence in stressful conditions because the functional capacity of any adaptation system is limited. Interestingly, AMPK can regulate metabolic processes in noncell-autonomous manner. The main effects of AMPK activation in the cell are realized in restriction of proliferation and launching autophagy. In tissues of an aging organism, the ability of AMPK to respond to energy deficit decreases; this fact is especially critical for organs that contain postmitotic cells. In this review, we have tried to consider the involvement of AMPK in age-related changes in the cell and in the organism.
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Affiliation(s)
- Galina V Morgunova
- Evolutionary Cytogerontology Sector, School of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Alexander A Klebanov
- Evolutionary Cytogerontology Sector, School of Biology, Lomonosov Moscow State University, Moscow, Russia
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13
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Hunter KS, Davies SJ. Host Adaptive Immune Status Regulates Expression of the Schistosome AMP-Activated Protein Kinase. Front Immunol 2018; 9:2699. [PMID: 30519243 PMCID: PMC6260181 DOI: 10.3389/fimmu.2018.02699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/01/2018] [Indexed: 12/25/2022] Open
Abstract
Schistosomes exhibit profound developmental adaptations in response to the immune status of their mammalian host, including significant attenuation of parasite growth, development and reproduction in response to deficits in host adaptive immunity. These observations led us to hypothesize that schistosomes regulate the utilization of energy resources in response to immunological conditions within the host. To test this hypothesis, we identified and characterized the Schistosoma mansoni AMP-activated protein kinase (AMPK), a heterotrimeric enzyme complex that is central to regulating energy metabolism at the cellular and organismal level in eukaryotes. We show that expression of the catalytic α subunit is developmentally regulated during the parasite life cycle, with peak expression occurring in adult worms. However, the protein is present and phosphorylated in all life cycle stages examined, suggesting a need for active regulation of energy resources throughout the life cycle. In contrast, transcription of the AMPK α gene is down-regulated in cercariae and schistosomula, suggesting that the protein in these life cycle stages is pre-synthesized in the sporocyst and that expression must be re-initiated once inside the mammalian host. We also show that schistosome AMPK α activity in adult worms is sensitive to changes in the parasite's environment, suggesting a mechanism by which schistosome metabolism may be responsive to host immune factors. Finally, we show that AMPK α expression is significantly down-regulated in parasites isolated from immunodeficient mice, suggesting that modulation of parasite energy metabolism may contribute to the attenuation of schistosome growth and reproduction in immunodeficient hosts. These findings provide insights into the molecular interactions between schistosomes and their vertebrate hosts and suggest that parasite energy metabolism may represent a novel target for anti-schistosome interventions.
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Affiliation(s)
- Kasandra S Hunter
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Stephen J Davies
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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14
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Miguel-Aliaga I, Jasper H, Lemaitre B. Anatomy and Physiology of the Digestive Tract of Drosophila melanogaster. Genetics 2018; 210:357-396. [PMID: 30287514 PMCID: PMC6216580 DOI: 10.1534/genetics.118.300224] [Citation(s) in RCA: 247] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/26/2018] [Indexed: 12/15/2022] Open
Abstract
The gastrointestinal tract has recently come to the forefront of multiple research fields. It is now recognized as a major source of signals modulating food intake, insulin secretion and energy balance. It is also a key player in immunity and, through its interaction with microbiota, can shape our physiology and behavior in complex and sometimes unexpected ways. The insect intestine had remained, by comparison, relatively unexplored until the identification of adult somatic stem cells in the Drosophila intestine over a decade ago. Since then, a growing scientific community has exploited the genetic amenability of this insect organ in powerful and creative ways. By doing so, we have shed light on a broad range of biological questions revolving around stem cells and their niches, interorgan signaling and immunity. Despite their relatively recent discovery, some of the mechanisms active in the intestine of flies have already been shown to be more widely applicable to other gastrointestinal systems, and may therefore become relevant in the context of human pathologies such as gastrointestinal cancers, aging, or obesity. This review summarizes our current knowledge of both the formation and function of the Drosophila melanogaster digestive tract, with a major focus on its main digestive/absorptive portion: the strikingly adaptable adult midgut.
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Affiliation(s)
- Irene Miguel-Aliaga
- Medical Research Council London Institute of Medical Sciences, Imperial College London, W12 0NN, United Kingdom
| | - Heinrich Jasper
- Buck Institute for Research on Aging, Novato, California 94945-1400
- Immunology Discovery, Genentech, Inc., San Francisco, California 94080
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École polytechnique fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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15
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Abstract
Excess adipose fat accumulation, or obesity, is a growing problem worldwide in terms of both the rate of incidence and the severity of obesity-associated metabolic disease. Adipose tissue evolved in animals as a specialized dynamic lipid storage depot: adipose cells synthesize fat (a process called lipogenesis) when energy is plentiful and mobilize stored fat (a process called lipolysis) when energy is needed. When a disruption of lipid homeostasis favors increased fat synthesis and storage with little turnover owing to genetic predisposition, overnutrition or sedentary living, complications such as diabetes and cardiovascular disease are more likely to arise. The vinegar fly Drosophila melanogaster (Diptera: Drosophilidae) is used as a model to better understand the mechanisms governing fat metabolism and distribution. Flies offer a wealth of paradigms with which to study the regulation and physiological effects of fat accumulation. Obese flies accumulate triacylglycerols in the fat body, an organ similar to mammalian adipose tissue, which specializes in lipid storage and catabolism. Discoveries in Drosophila have ranged from endocrine hormones that control obesity to subcellular mechanisms that regulate lipogenesis and lipolysis, many of which are evolutionarily conserved. Furthermore, obese flies exhibit pathophysiological complications, including hyperglycemia, reduced longevity and cardiovascular function - similar to those observed in obese humans. Here, we review some of the salient features of the fly that enable researchers to study the contributions of feeding, absorption, distribution and the metabolism of lipids to systemic physiology.
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Affiliation(s)
- Laura Palanker Musselman
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, NY 13902, USA
| | - Ronald P Kühnlein
- Department of Biochemistry 1, Institute of Molecular Biosciences, University of Graz, Humboldtstraβe 50/II, A-8010 Graz, Austria.,BioTechMed-Graz, Graz, Austria
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16
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Min S, Yoon W, Cho H, Chung J. Misato underlies visceral myopathy in Drosophila. Sci Rep 2017; 7:17700. [PMID: 29255146 PMCID: PMC5735100 DOI: 10.1038/s41598-017-17961-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/01/2017] [Indexed: 11/12/2022] Open
Abstract
Genetic mechanisms for the pathogenesis of visceral myopathy (VM) have been rarely demonstrated. Here we report the visceral role of misato (mst) in Drosophila and its implications for the pathogenesis of VM. Depletion of mst using three independent RNAi lines expressed by a pan-muscular driver elicited characteristic symptoms of VM, such as abnormal dilation of intestinal tracts, reduced gut motility, feeding defects, and decreased life span. By contrast, exaggerated expression of mst reduced intestine diameters, but increased intestinal motilities along with thickened muscle fibers, demonstrating a critical role of mst in the visceral muscle. Mst expression was detected in the adult intestine with its prominent localization to actin filaments and was required for maintenance of intestinal tubulin and actomyosin structures. Consistent with the subcellular localization of Mst, the intestinal defects induced by mst depletion were dramatically rescued by exogenous expression of an actin member. Upon ageing the intestinal defects were deteriorative with marked increase of apoptotic responses in the visceral muscle. Taken together, we propose the impairment of actomyosin structures induced by mst depletion in the visceral muscle as a pathogenic mechanism for VM.
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Affiliation(s)
- Soohong Min
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Institute of Molecular Biology and Genetics, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea.,Harvard Medical School, Department of Cell Biology, 240 Longwood Avenue, Seeley-Mudd Building, Boston, MA, 02115, USA
| | - Woongchang Yoon
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Institute of Molecular Biology and Genetics, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea.,School of Biological Sciences, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea
| | - Hyunho Cho
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Institute of Molecular Biology and Genetics, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea.,School of Biological Sciences, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea
| | - Jongkyeong Chung
- National Creative Research Initiatives Center for Energy Homeostasis Regulation, Institute of Molecular Biology and Genetics, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea. .,School of Biological Sciences, Seoul National University, 1 Gwanak-Ro, Gwanak-Gu, Seoul, 08826, Republic of Korea.
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17
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AMP-activated protein kinase protects against anoxia in Drosophila melanogaster. Comp Biochem Physiol A Mol Integr Physiol 2017; 214:30-39. [DOI: 10.1016/j.cbpa.2017.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/08/2017] [Accepted: 09/08/2017] [Indexed: 01/18/2023]
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18
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Cremonini E, Wang Z, Bettaieb A, Adamo AM, Daveri E, Mills DA, Kalanetra KM, Haj FG, Karakas S, Oteiza PI. (-)-Epicatechin protects the intestinal barrier from high fat diet-induced permeabilization: Implications for steatosis and insulin resistance. Redox Biol 2017; 14:588-599. [PMID: 29154190 PMCID: PMC5691220 DOI: 10.1016/j.redox.2017.11.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 10/31/2017] [Accepted: 11/03/2017] [Indexed: 02/09/2023] Open
Abstract
Increased permeability of the intestinal barrier is proposed as an underlying factor for obesity-associated pathologies. Consumption of high fat diets (HFD) is associated with increased intestinal permeabilization and increased paracellular transport of endotoxins which can promote steatosis and insulin resistance. This study investigated whether dietary (-)-epicatechin (EC) supplementation can protect the intestinal barrier against HFD-induced permeabilization and endotoxemia, and mitigate liver damage and insulin resistance. Mechanisms leading to loss of integrity and function of the tight junction (TJ) were characterized. Consumption of a HFD for 15 weeks caused obesity, steatosis, and insulin resistance in male C57BL/6J mice. This was associated with increased intestinal permeability, decreased expression of ileal TJ proteins, and endotoxemia. Supplementation with EC (2-20mg/kg body weight) mitigated all these adverse effects. EC acted modulating cell signals and the gut hormone GLP-2, which are central to the regulation of intestinal permeability. Thus, EC prevented HFD-induced ileum NOX1/NOX4 upregulation, protein oxidation, and the activation of the redox-sensitive NF-κB and ERK1/2 pathways. Supporting NADPH oxidase as a target of EC actions, in Caco-2 cells EC and apocynin inhibited tumor necrosis alpha (TNFα)-induced NOX1/NOX4 overexpression, protein oxidation and monolayer permeabilization. Together, our findings demonstrate protective effects of EC against HFD-induced increased intestinal permeability and endotoxemia. This can in part underlie EC capacity to prevent steatosis and insulin resistance occurring as a consequence of HFD consumption.
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Affiliation(s)
- Eleonora Cremonini
- Department of Nutrition, University of California, Davis, USA; Department of Environmental Toxicology, University of California, Davis, USA
| | - Ziwei Wang
- Department of Nutrition, University of California, Davis, USA; Department of Environmental Toxicology, University of California, Davis, USA
| | - Ahmed Bettaieb
- Department of Nutrition, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Ana M Adamo
- Department of Biological Chemistry and IQUIFIB (UBA-CONICET), School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Elena Daveri
- Department of Nutrition, University of California, Davis, USA; Department of Environmental Toxicology, University of California, Davis, USA
| | - David A Mills
- Department of Food Science and Technology, University of California, Davis, USA; Department of Viticulture and Enology, University of California, Davis, USA
| | - Karen M Kalanetra
- Department of Food Science and Technology, University of California, Davis, USA; Department of Viticulture and Enology, University of California, Davis, USA
| | - Fawaz G Haj
- Department of Nutrition, University of California, Davis, USA; Department of Environmental Toxicology, University of California, Davis, USA
| | - Sidika Karakas
- Department of Internal Medicine, University of California, Davis, USA
| | - Patricia I Oteiza
- Department of Nutrition, University of California, Davis, USA; Department of Environmental Toxicology, University of California, Davis, USA.
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19
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Brookheart RT, Duncan JG. Modeling dietary influences on offspring metabolic programming in Drosophila melanogaster. Reproduction 2017; 152:R79-90. [PMID: 27450801 DOI: 10.1530/rep-15-0595] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 05/17/2016] [Indexed: 01/08/2023]
Abstract
The influence of nutrition on offspring metabolism has become a hot topic in recent years owing to the growing prevalence of maternal and childhood obesity. Studies in mammals have identified several factors correlating with parental and early offspring dietary influences on progeny health; however, the molecular mechanisms that underlie these factors remain undiscovered. Mammalian metabolic tissues and pathways are heavily conserved in Drosophila melanogaster, making the fly an invaluable genetic model organism for studying metabolism. In this review, we discuss the metabolic similarities between mammals and Drosophila and present evidence supporting its use as an emerging model of metabolic programming.
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Affiliation(s)
- Rita T Brookheart
- Department of PediatricsWashington University School of Medicine, St Louis, MO, USA
| | - Jennifer G Duncan
- Department of PediatricsWashington University School of Medicine, St Louis, MO, USA
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20
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Megha , Hasan G. Control of protein translation by IP 3R-mediated Ca 2+ release in Drosophila neuroendocrine cells. Fly (Austin) 2017; 11:0. [PMID: 28949794 PMCID: PMC5721944 DOI: 10.1080/19336934.2017.1384103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 12/25/2022] Open
Abstract
The inositol 1,4,5-trisphosphate receptor (IP3R) is one of two Ca2+ channels that gates Ca2+ release from ER-stores. The ligand IP3, generated upon specific G-protein coupled receptor activation, binds to IP3R to release Ca2+ into the cytosol. IP3R also mediates ER-store Ca2+ release into the mitochondria, under basal as well as stimulatory conditions; an activity that influences cellular bioenergetics and thus, cellular growth and proliferation. In Drosophila neuroendocrine cells expressing a hypomorphic mutant of IP3R, we observed reduced protein translation levels. Here, we discuss the possible molecular mechanism for this observation. We hypothesise that the cellular energy sensor, AMPK connects IP3R mediated Ca2+ release into the mitochondria, to protein translation, via the TOR pathway.
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Affiliation(s)
- Megha
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
| | - Gaiti Hasan
- National Centre for Biological Sciences-TIFR, GKVK Campus, Bangalore, India
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21
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Sun X, Zhu MJ. AMP-activated protein kinase: a therapeutic target in intestinal diseases. Open Biol 2017; 7:170104. [PMID: 28835570 PMCID: PMC5577448 DOI: 10.1098/rsob.170104] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/25/2017] [Indexed: 02/07/2023] Open
Abstract
Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a highly conserved energy sensor, has a crucial role in cardiovascular, neurodegenerative and inflammatory diseases, as well as in cancer and metabolic disorders. Accumulating studies have demonstrated that AMPK activation enhances paracellular junctions, nutrient transporters, autophagy and apoptosis, and suppresses inflammation and carcinogenesis in the intestine, indicating an essential role of AMPK in intestinal health. AMPK inactivation is an aetiological factor in intestinal dysfunctions. This review summarizes the favourable outcomes of AMPK activation on intestinal health, and discusses AMPK as a potential therapeutic target for intestinal diseases.
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Affiliation(s)
- Xiaofei Sun
- School of Food Science, Washington State University, Pullman, WA 99164, USA
- School of Food Science, University of Idaho, Moscow, ID 83844, USA
| | - Mei-Jun Zhu
- School of Food Science, Washington State University, Pullman, WA 99164, USA
- School of Food Science, University of Idaho, Moscow, ID 83844, USA
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22
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Liu Q, Jin LH. Organ-to-Organ Communication: A Drosophila Gastrointestinal Tract Perspective. Front Cell Dev Biol 2017; 5:29. [PMID: 28421183 PMCID: PMC5376570 DOI: 10.3389/fcell.2017.00029] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/15/2017] [Indexed: 01/05/2023] Open
Abstract
The long-term maintenance of an organism's homeostasis and health relies on the accurate regulation of organ-organ communication. Recently, there has been growing interest in using the Drosophila gastrointestinal tract to elucidate the regulatory programs that underlie the complex interactions between organs. Data obtained in this field have dramatically improved our understanding of how organ-organ communication contributes to the regulation of various aspects of the intestine, including its metabolic and physiological status. However, although research uncovering regulatory programs associated with interorgan communication has provided key insights, the underlying mechanisms have not been extensively explored. In this review, we highlight recent findings describing gut-neighbor and neighbor-neighbor communication models in adults and larvae, respectively, with a special focus on how a range of critical strategies concerning continuous interorgan communication and adjustment can be used to manipulate different aspects of biological processes. Given the high degree of similarity between the Drosophila and mammalian intestinal epithelia, it can be anticipated that further analyses of the Drosophila gastrointestinal tract will facilitate the discovery of similar mechanisms underlying organ-organ communication in other mammalian organs, such as the human intestine.
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Affiliation(s)
- Qiang Liu
- Department of Genetics, College of Life Sciences, Northeast Forestry UniversityHarbin, China
| | - Li Hua Jin
- Department of Genetics, College of Life Sciences, Northeast Forestry UniversityHarbin, China
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23
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Kaushik G, Leijten J, Khademhosseini A. Concise Review: Organ Engineering: Design, Technology, and Integration. Stem Cells 2017; 35:51-60. [PMID: 27641724 PMCID: PMC6527109 DOI: 10.1002/stem.2502] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 08/30/2016] [Accepted: 09/06/2016] [Indexed: 01/19/2023]
Abstract
Engineering complex tissues and whole organs has the potential to dramatically impact translational medicine in several avenues. Organ engineering is a discipline that integrates biological knowledge of embryological development, anatomy, physiology, and cellular interactions with enabling technologies including biocompatible biomaterials and biofabrication platforms such as three-dimensional bioprinting. When engineering complex tissues and organs, core design principles must be taken into account, such as the structure-function relationship, biochemical signaling, mechanics, gradients, and spatial constraints. Technological advances in biomaterials, biofabrication, and biomedical imaging allow for in vitro control of these factors to recreate in vivo phenomena. Finally, organ engineering emerges as an integration of biological design and technical rigor. An overall workflow for organ engineering and guiding technology to advance biology as well as a perspective on necessary future iterations in the field is discussed. Stem Cells 2017;35:51-60.
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Affiliation(s)
- Gaurav Kaushik
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, Massachusetts, USA
| | - Jeroen Leijten
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, Massachusetts, USA
- Department of Developmental BioEngineering, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Ali Khademhosseini
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women’s Hospital, Harvard Medical School, Cambridge, Massachusetts, USA
- Department of Physics, King Abdulaziz University, Jeddah, 21569, Saudi Arabia, USA
- Department of Bioindustrial Technologies, College of Animal Bioscience and Technology, Konkuk University, Hwayang-dong, Gwangjin-gu, Seoul, Republic of Korea
- Department of Physics, King Abdulaziz University, Jeddah, Saudi Arabia
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24
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Bland ML. Measurement of Carbon Dioxide Production from Radiolabeled Substrates in Drosophila melanogaster. J Vis Exp 2016. [PMID: 27404635 PMCID: PMC4993251 DOI: 10.3791/54045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The power of Drosophila genetics is increasingly being applied to questions of hormone signaling and metabolism and to the development of models of human disease in this organism. Sensitive methods for measurements of parameters such as metabolic rates are needed to drive the understanding of physiology and disease in small animals such as the fruit fly. The method described here assesses fuel oxidation in small numbers of adult flies fed food containing trace amounts of 14C-labeled substrates such as glucose or fatty acid. After the feeding period and any additional experimental manipulations, flies are transferred to short tubes capped with mesh, which are then placed in glass vials containing KOH-saturated filter paper that traps exhaled, radiolabeled CO2 generated from oxidation of radiolabeled substrates as potassium bicarbonate, KHCO3. This radiolabeled bicarbonate is measured by scintillation counting. This is a quantitative, reproducible, and simple approach for the study of fuel oxidation. The use of radiolabeled glucose, fatty acids, or amino acids allows determination of the contribution of these different fuel sources to energy metabolism under different conditions such as feeding and fasting and in different genetic backgrounds. This complements other approaches used to measure in vivo energy metabolism and should further the understanding of metabolic regulation.
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25
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Abstract
AMPK is an evolutionary conserved energy sensor involved in the regulation of energy metabolism. Based on biochemical studies, AMPK has brought much of interest in recent years due to its potential impact on metabolic disorders. Suitable animal models are therefore essential to promote our understanding of the molecular and functional roles of AMPK but also to bring novel information for the development of novel therapeutic strategies. The organism systems include pig (Sus scrofa), mouse (Mus musculus), fly (Drosophila melanogaster), worm (Caenorhabditis elegans), and fish (Danio rerio) models. These animal models have provided reliable experimental evidence demonstrating the crucial role of AMPK in the regulation of metabolism but also of cell polarity, autophagy, and oxidative stress. In this chapter, we update the new development in the generation and application of animal models for the study of AMPK biology. We also discuss recent breakthroughs from studies in mice, flies, and worms showing how AMPK has a primary role in initiating or promoting pathological or beneficial impact on health.
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Affiliation(s)
- Benoit Viollet
- INSERM U1016, Institut Cochin, Paris, France. .,CNRS UMR 8104, Paris, France. .,Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
| | - Marc Foretz
- INSERM U1016, Institut Cochin, Paris, France.,CNRS UMR 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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26
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Piegholdt S, Rimbach G, Wagner AE. The phytoestrogen prunetin affects body composition and improves fitness and lifespan in male
Drosophila melanogaster. FASEB J 2015; 30:948-58. [DOI: 10.1096/fj.15-282061] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 10/19/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Stefanie Piegholdt
- Institute of Human Nutrition and Food ScienceUniversity of KielKielGermany
| | - Gerald Rimbach
- Institute of Human Nutrition and Food ScienceUniversity of KielKielGermany
| | - Anika E. Wagner
- Institute of Human Nutrition and Food ScienceUniversity of KielKielGermany
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27
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Carvalho MJA, Mirth CK. Coordinating morphology with behavior during development: an integrative approach from a fly perspective. Front Ecol Evol 2015. [DOI: 10.3389/fevo.2015.00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ulgherait M, Rana A, Rera M, Graniel J, Walker DW. AMPK modulates tissue and organismal aging in a non-cell-autonomous manner. Cell Rep 2014; 8:1767-1780. [PMID: 25199830 PMCID: PMC4177313 DOI: 10.1016/j.celrep.2014.08.006] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 06/09/2014] [Accepted: 08/01/2014] [Indexed: 01/29/2023] Open
Abstract
AMPK exerts prolongevity effects in diverse species; however, the tissue-specific mechanisms involved are poorly understood. Here, we show that upregulation of AMPK in the adult Drosophila nervous system induces autophagy both in the brain and also in the intestinal epithelium. Induction of autophagy is linked to improved intestinal homeostasis during aging and extended lifespan. Neuronal upregulation of the autophagy-specific protein kinase Atg1 is both necessary and sufficient to induce these intertissue effects during aging and to prolong the lifespan. Furthermore, upregulation of AMPK in the adult intestine induces autophagy both cell autonomously and non-cell-autonomously in the brain, slows systemic aging, and prolongs the lifespan. We show that the organism-wide response to tissue-specific AMPK/Atg1 activation is linked to reduced insulin-like peptide levels in the brain and a systemic increase in 4E-BP expression. Together, these results reveal that localized activation of AMPK and/or Atg1 in key tissues can slow aging in a non-cell-autonomous manner.
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Affiliation(s)
- Matthew Ulgherait
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095, USA,Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - Anil Rana
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - Michael Rera
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - Jacqueline Graniel
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095, USA
| | - David W. Walker
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, California 90095, USA,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095, USA,Correspondence: David W. Walker, Ph.D., , Phone: 310-825-7179
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Appocher C, Klima R, Feiguin F. Functional screening in Drosophila reveals the conserved role of REEP1 in promoting stress resistance and preventing the formation of Tau aggregates. Hum Mol Genet 2014; 23:6762-72. [DOI: 10.1093/hmg/ddu393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Small molecule drug screening in Drosophila identifies the 5HT2A receptor as a feeding modulation target. Sci Rep 2013; 3:srep02120. [PMID: 23817146 PMCID: PMC3698492 DOI: 10.1038/srep02120] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 06/14/2013] [Indexed: 12/22/2022] Open
Abstract
Dysregulation of eating behavior can lead to obesity, which affects 10% of the adult population worldwide and accounts for nearly 3 million deaths every year. Despite this burden on society, we currently lack effective pharmacological treatment options to regulate appetite. We used Drosophila melanogaster larvae to develop a high-throughput whole organism screen for drugs that modulate food intake. In a screen of 3630 small molecules, we identified the serotonin (5-hydroxytryptamine or 5-HT) receptor antagonist metitepine as a potent anorectic drug. Using cell-based assays we show that metitepine is an antagonist of all five Drosophila 5-HT receptors. We screened fly mutants for each of these receptors and found that serotonin receptor 5-HT2A is the sole molecular target for feeding inhibition by metitepine. These results highlight the conservation of molecular mechanisms controlling appetite and provide a method for unbiased whole-organism drug screens to identify novel drugs and molecular pathways modulating food intake.
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Koyama T, Mendes CC, Mirth CK. Mechanisms regulating nutrition-dependent developmental plasticity through organ-specific effects in insects. Front Physiol 2013; 4:263. [PMID: 24133450 PMCID: PMC3783933 DOI: 10.3389/fphys.2013.00263] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 09/06/2013] [Indexed: 12/25/2022] Open
Abstract
Nutrition, via the insulin/insulin-like growth factor (IIS)/Target of Rapamycin (TOR) signaling pathway, can provide a strong molding force for determining animal size and shape. For instance, nutrition induces a disproportionate increase in the size of male horns in dung and rhinoceros beetles, or mandibles in staghorn or horned flour beetles, relative to body size. In these species, well-fed male larvae produce adults with greatly enlarged horns or mandibles, whereas males that are starved or poorly fed as larvae bear much more modest appendages. Changes in IIS/TOR signaling plays a key role in appendage development by regulating growth in the horn and mandible primordia. In contrast, changes in the IIS/TOR pathway produce minimal effects on the size of other adult structures, such as the male genitalia in fruit flies and dung beetles. The horn, mandible and genitalia illustrate that although all tissues are exposed to the same hormonal environment within the larval body, the extent to which insulin can induce growth is organ specific. In addition, the IIS/TOR pathway affects body size and shape by controlling production of metamorphic hormones important for regulating developmental timing, like the steroid molting hormone ecdysone and sesquiterpenoid hormone juvenile hormone. In this review, we discuss recent results from Drosophila and other insects that highlight mechanisms allowing tissues to differ in their sensitivity to IIS/TOR and the potential consequences of these differences on body size and shape.
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Affiliation(s)
- Takashi Koyama
- Development, Evolution and the Environment Laboratory, Instituto Gulbenkian de Ciência Oeiras, Portugal
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Energy-dependent modulation of glucagon-like signaling in Drosophila via the AMP-activated protein kinase. Genetics 2012; 192:457-66. [PMID: 22798489 DOI: 10.1534/genetics.112.143610] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Adipokinetic hormone (AKH) is the equivalent of mammalian glucagon, as it is the primary insect hormone that causes energy mobilization. In Drosophila, current knowledge of the mechanisms regulating AKH signaling is limited. Here, we report that AMP-activated protein kinase (AMPK) is critical for normal AKH secretion during periods of metabolic challenges. Reduction of AMPK in AKH cells causes a suite of behavioral and physiological phenotypes resembling AKH cell ablations. Specifically, reduced AMPK function increases life span during starvation and delays starvation-induced hyperactivity. Neither AKH cell survival nor gene expression is significantly impacted by reduced AMPK function. AKH immunolabeling was significantly higher in animals with reduced AMPK function; this result is paralleled by genetic inhibition of synaptic release, suggesting that AMPK promotes AKH secretion. We observed reduced secretion in AKH cells bearing AMPK mutations employing a specific secretion reporter, confirming that AMPK functions in AKH secretion. Live-cell imaging of wild-type AKH neuroendocrine cells shows heightened excitability under reduced sugar levels, and this response was delayed and reduced in AMPK-deficient backgrounds. Furthermore, AMPK activation in AKH cells increases intracellular calcium levels in constant high sugar levels, suggesting that the underlying mechanism of AMPK action is modification of ionic currents. These results demonstrate that AMPK signaling is a critical feature that regulates AKH secretion, and, ultimately, metabolic homeostasis. The significance of these findings is that AMPK is important in the regulation of glucagon signaling, suggesting that the organization of metabolic networks is highly conserved and that AMPK plays a prominent role in these networks.
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Oliveira SM, Zhang YH, Solis RS, Isackson H, Bellahcene M, Yavari A, Pinter K, Davies JK, Ge Y, Ashrafian H, Walker JW, Carling D, Watkins H, Casadei B, Redwood C. AMP-activated protein kinase phosphorylates cardiac troponin I and alters contractility of murine ventricular myocytes. Circ Res 2012; 110:1192-201. [PMID: 22456184 DOI: 10.1161/circresaha.111.259952] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
RATIONALE AMP-activated protein kinase (AMPK) is an important regulator of energy balance and signaling in the heart. Mutations affecting the regulatory γ2 subunit have been shown to cause an essentially cardiac-restricted phenotype of hypertrophy and conduction disease, suggesting a specific role for this subunit in the heart. OBJECTIVE The γ isoforms are highly conserved at their C-termini but have unique N-terminal sequences, and we hypothesized that the N-terminus of γ2 may be involved in conferring substrate specificity or in determining intracellular localization. METHODS AND RESULTS A yeast 2-hybrid screen of a human heart cDNA library using the N-terminal 273 residues of γ2 as bait identified cardiac troponin I (cTnI) as a putative interactor. In vitro studies showed that cTnI is a good AMPK substrate and that Ser150 is the principal residue phosphorylated. Furthermore, on AMPK activation during ischemia, Ser150 is phosphorylated in whole hearts. Using phosphomimics, measurements of actomyosin ATPase in vitro and force generation in demembraneated trabeculae showed that modification at Ser150 resulted in increased Ca(2+) sensitivity of contractile regulation. Treatment of cardiomyocytes with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) resulted in increased myocyte contractility without changing the amplitude of Ca(2+) transient and prolonged relaxation despite shortening the time constant of Ca(2+) transient decay (tau). Compound C prevented the effect of AICAR on myocyte function. These results suggest that AMPK activation increases myocyte contraction and prolongs relaxation by increasing myofilament Ca(2+) sensitivity. CONCLUSIONS We conclude that cTnI phosphorylation by AMPK may represent a novel mechanism of regulation of cardiac function.
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Andersen RO, Turnbull DW, Johnson EA, Doe CQ. Sgt1 acts via an LKB1/AMPK pathway to establish cortical polarity in larval neuroblasts. Dev Biol 2012; 363:258-65. [PMID: 22248825 DOI: 10.1016/j.ydbio.2011.12.047] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 11/25/2011] [Accepted: 12/30/2011] [Indexed: 10/14/2022]
Abstract
Drosophila neuroblasts are a model system for studying stem cell self-renewal and the establishment of cortical polarity. Larval neuroblasts generate a large apical self-renewing neuroblast, and a small basal cell that differentiates. We performed a genetic screen to identify regulators of neuroblast self-renewal, and identified a mutation in sgt1 (suppressor-of-G2-allele-of-skp1) that had fewer neuroblasts. We found that sgt1 neuroblasts have two polarity phenotypes: failure to establish apical cortical polarity at prophase, and lack of cortical Scribble localization throughout the cell cycle. Apical cortical polarity was partially restored at metaphase by a microtubule-induced cortical polarity pathway. Double mutants lacking Sgt1 and Pins (a microtubule-induced polarity pathway component) resulted in neuroblasts without detectable cortical polarity and formation of "neuroblast tumors." Mutants in hsp83 (encoding the predicted Sgt1-binding protein Hsp90), LKB1, or AMPKα all show similar prophase apical cortical polarity defects (but no Scribble phenotype), and activated AMPKα rescued the sgt1 mutant phenotype. We propose that an Sgt1/Hsp90-LKB1-AMPK pathway acts redundantly with a microtubule-induced polarity pathway to generate neuroblast cortical polarity, and the absence of neuroblast cortical polarity can produce neuroblast tumors.
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Affiliation(s)
- Ryan O Andersen
- Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403, USA
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35
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Weake VM, Workman JL. SAGA function in tissue-specific gene expression. Trends Cell Biol 2011; 22:177-84. [PMID: 22196215 DOI: 10.1016/j.tcb.2011.11.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Revised: 11/23/2011] [Accepted: 11/23/2011] [Indexed: 01/28/2023]
Abstract
The Spt-Ada-Gcn5-acetyltransferase (SAGA) transcription coactivator plays multiple roles in regulating transcription because of the presence of functionally independent modules of subunits within the complex. We have recently identified a role for the ubiquitin protease activity of SAGA in regulating tissue-specific gene expression in Drosophila. Here, we discuss the modular nature of SAGA and the different mechanisms through which SAGA is recruited to target promoters. We propose that the genes sensitive to loss of the ubiquitin protease activity of SAGA share functional characteristics that require deubiquitination of monoubiquitinated histone H2B (ubH2B) for full activation. We hypothesize that deubiquitination of ubH2B by SAGA destabilizes promoter nucleosomes, thus enhancing recruitment of RNA polymerase II (Pol II) to weak promoters. In addition, SAGA-mediated deubiquitination of ubH2B may facilitate binding of factors that are important for the transition of paused Pol II into transcription elongation.
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Affiliation(s)
- Vikki M Weake
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
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36
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Affiliation(s)
- Michelle L Bland
- Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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37
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Johnson EC, Kazgan N, Bretz CA, Forsberg LJ, Hector CE, Worthen RJ, Onyenwoke R, Brenman JE. Altered metabolism and persistent starvation behaviors caused by reduced AMPK function in Drosophila. PLoS One 2010; 5. [PMID: 20862213 PMCID: PMC2942814 DOI: 10.1371/journal.pone.0012799] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 08/21/2010] [Indexed: 12/21/2022] Open
Abstract
Organisms must utilize multiple mechanisms to maintain energetic homeostasis in the face of limited nutrient availability. One mechanism involves activation of the heterotrimeric AMP-activated protein kinase (AMPK), a cell-autonomous sensor to energetic changes regulated by ATP to AMP ratios. We examined the phenotypic consequences of reduced AMPK function, both through RNAi knockdown of the gamma subunit (AMPKγ) and through expression of a dominant negative alpha (AMPKα) variant in Drosophila melanogaster. Reduced AMPK signaling leads to hypersensitivity to starvation conditions as measured by lifespan and locomotor activity. Locomotor levels in flies with reduced AMPK function were lower during unstressed conditions, but starvation-induced hyperactivity, an adaptive response to encourage foraging, was significantly higher than in wild type. Unexpectedly, total dietary intake was greater in animals with reduced AMPK function yet total triglyceride levels were lower. AMPK mutant animals displayed starvation-like lipid accumulation patterns in metabolically key liver-like cells, oenocytes, even under fed conditions, consistent with a persistent starved state. Measurements of O2 consumption reveal that metabolic rates are greater in animals with reduced AMPK function. Lastly, rapamycin treatment tempers the starvation sensitivity and lethality associated with reduced AMPK function. Collectively, these results are consistent with models that AMPK shifts energy usage away from expenditures into a conservation mode during nutrient-limited conditions at a cellular level. The highly conserved AMPK subunits throughout the Metazoa, suggest such findings may provide significant insight for pharmaceutical strategies to manipulate AMPK function in humans.
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Affiliation(s)
- Erik C. Johnson
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States of America
- Translational Science Center, Wake Forest University, Winston-Salem, North Carolina, United States of America
- * E-mail: (ECJ); (JEB)
| | - Nevzat Kazgan
- Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Colin A. Bretz
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States of America
| | - Lawrence J. Forsberg
- Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Clare E. Hector
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, United States of America
| | - Ryan J. Worthen
- Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Rob Onyenwoke
- Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Jay E. Brenman
- Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail: (ECJ); (JEB)
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