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Ghalayini J, Boulianne GL. Deciphering mechanisms of action of ACE inhibitors in neurodegeneration using Drosophila models of Alzheimer's disease. Front Neurosci 2023; 17:1166973. [PMID: 37113150 PMCID: PMC10126366 DOI: 10.3389/fnins.2023.1166973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/17/2023] [Indexed: 04/29/2023] Open
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder for which there is no cure. Recently, several studies have reported a significant reduction in the incidence and progression of dementia among some patients receiving antihypertensive medications such as angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs). Why these drugs are beneficial in some AD patients and not others is unclear although it has been shown to be independent of their role in regulating blood pressure. Given the enormous and immediate potential of ACE-Is and ARBs for AD therapeutics it is imperative that we understand how they function. Recently, studies have shown that ACE-Is and ARBs, which target the renin angiotensin system in mammals, are also effective in suppressing neuronal cell death and memory defects in Drosophila models of AD despite the fact that this pathway is not conserved in flies. This suggests that the beneficial effects of these drugs may be mediated by distinct and as yet, identified mechanisms. Here, we discuss how the short lifespan and ease of genetic manipulations available in Drosophila provide us with a unique and unparalleled opportunity to rapidly identify the targets of ACE-Is and ARBs and evaluate their therapeutic effectiveness in robust models of AD.
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Affiliation(s)
- Judy Ghalayini
- Program in Developmental and Stem Cell Biology, Peter Gilgin Center for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Gabrielle L. Boulianne
- Program in Developmental and Stem Cell Biology, Peter Gilgin Center for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- *Correspondence: Gabrielle L. Boulianne,
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2
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Papagerakis S, Said R, Ketabat F, Mahmood R, Pundir M, Lobanova L, Guenther G, Pannone G, Lavender K, McAlpin BR, Moreau A, Chen X, Papagerakis P. When the clock ticks wrong with COVID-19. Clin Transl Med 2022; 12:e949. [PMID: 36394205 PMCID: PMC9670202 DOI: 10.1002/ctm2.949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/06/2022] [Accepted: 06/11/2022] [Indexed: 11/18/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a member of the coronavirus family that causes the novel coronavirus disease first diagnosed in 2019 (COVID-19). Although many studies have been carried out in recent months to determine why the disease clinical presentations and outcomes can vary significantly from asymptomatic to severe or lethal, the underlying mechanisms are not fully understood. It is likely that unique individual characteristics can strongly influence the broad disease variability; thus, tailored diagnostic and therapeutic approaches are needed to improve clinical outcomes. The circadian clock is a critical regulatory mechanism orchestrating major physiological and pathological processes. It is generally accepted that more than half of the cell-specific genes in any given organ are under circadian control. Although it is known that a specific role of the circadian clock is to coordinate the immune system's steady-state function and response to infectious threats, the links between the circadian clock and SARS-CoV-2 infection are only now emerging. How inter-individual variability of the circadian profile and its dysregulation may play a role in the differences noted in the COVID-19-related disease presentations, and outcome remains largely underinvestigated. This review summarizes the current evidence on the potential links between circadian clock dysregulation and SARS-CoV-2 infection susceptibility, disease presentation and progression, and clinical outcomes. Further research in this area may contribute towards novel circadian-centred prognostic, diagnostic and therapeutic approaches for COVID-19 in the era of precision health.
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Affiliation(s)
- Silvana Papagerakis
- Laboratory of Oral, Head and Neck Cancer – Personalized Diagnostics and Therapeutics, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Surgery, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Division of Biomedical EngineeringUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Biochemistry, Microbiology and Immunology, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Otolaryngology – Head and Neck Surgery, Medical SchoolThe University of MichiganAnn ArborMichiganUSA
| | - Raed Said
- Laboratory of Oral, Head and Neck Cancer – Personalized Diagnostics and Therapeutics, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Surgery, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Laboratory of Precision Oral Health and Chronobiology, College of DentistryUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Anatomy, Physiology and Pharmacology, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Farinaz Ketabat
- Laboratory of Oral, Head and Neck Cancer – Personalized Diagnostics and Therapeutics, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Division of Biomedical EngineeringUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Razi Mahmood
- Laboratory of Oral, Head and Neck Cancer – Personalized Diagnostics and Therapeutics, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Surgery, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Laboratory of Precision Oral Health and Chronobiology, College of DentistryUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Meenakshi Pundir
- Laboratory of Oral, Head and Neck Cancer – Personalized Diagnostics and Therapeutics, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Division of Biomedical EngineeringUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Laboratory of Precision Oral Health and Chronobiology, College of DentistryUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Liubov Lobanova
- Laboratory of Precision Oral Health and Chronobiology, College of DentistryUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Greg Guenther
- Laboratory of Oral, Head and Neck Cancer – Personalized Diagnostics and Therapeutics, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Giuseppe Pannone
- Anatomic Pathology Unit, Department of Clinic and Experimental MedicineUniversity of FoggiaFoggiaItaly
| | - Kerry Lavender
- Department of Biochemistry, Microbiology and Immunology, College of MedicineUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Blake R. McAlpin
- Laboratories of Neuroimmunology, Department of Symptom Research, Division of Internal MedicineThe University of Texas MD Anderson Cancer CenterHoustonTexasUSA
| | - Alain Moreau
- Viscogliosi Laboratory in Molecular Genetics of Musculoskeletal DiseasesCentre Hospitalier Universitaire (CHU) Sainte‐Justine Research CenterMontrealQuebecCanada,Department of Stomatology, Faculty of Dentistry and Department of Biochemistry and Molecular Medicine, Faculty of MedicineUniversité de MontréalMontrealQuebecCanada
| | - Xiongbiao Chen
- Division of Biomedical EngineeringUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Department of Mechanical Engineering, School of EngineeringUniversity of SaskatchewanSaskatoonSaskatchewanCanada
| | - Petros Papagerakis
- Division of Biomedical EngineeringUniversity of SaskatchewanSaskatoonSaskatchewanCanada,Laboratory of Precision Oral Health and Chronobiology, College of DentistryUniversity of SaskatchewanSaskatoonSaskatchewanCanada
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3
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Egan BM, Scharf A, Pohl F, Kornfeld K. Control of aging by the renin–angiotensin system: a review of C. elegans, Drosophila, and mammals. Front Pharmacol 2022; 13:938650. [PMID: 36188619 PMCID: PMC9518657 DOI: 10.3389/fphar.2022.938650] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
The free-living, non-parasitic nematode Caenorhabditis elegans is a premier model organism for the study of aging and longevity due to its short lifespan, powerful genetic tools, and conservation of fundamental mechanisms with mammals. Approximately 70 percent of human genes have homologs in C. elegans, including many that encode proteins in pathways that influence aging. Numerous genetic pathways have been identified in C. elegans that affect lifespan, including the dietary restriction pathway, the insulin/insulin-like growth factor (IGF) signaling pathway, and the disruption of components of the mitochondrial electron transport chain. C. elegans is also a powerful system for performing drug screens, and many lifespan-extending compounds have been reported; notably, several FDA-approved medications extend the lifespan in C. elegans, raising the possibility that they can also extend the lifespan in humans. The renin–angiotensin system (RAS) in mammals is an endocrine system that regulates blood pressure and a paracrine system that acts in a wide range of tissues to control physiological processes; it is a popular target for drugs that reduce blood pressure, including angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs). Emerging evidence indicates that this system influences aging. In C. elegans, decreasing the activity of the ACE homolog acn-1 or treatment with the ACE-inhibitor Captopril significantly extends the lifespan. In Drosophila, treatment with ACE inhibitors extends the lifespan. In rodents, manipulating the RAS with genetic or pharmacological interventions can extend the lifespan. In humans, polymorphisms in the ACE gene are associated with extreme longevity. These results suggest the RAS plays a conserved role in controlling longevity. Here, we review studies of the RAS and aging, emphasizing the potential of C. elegans as a model for understanding the mechanism of lifespan control.
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Affiliation(s)
- Brian M. Egan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
| | - Andrea Scharf
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, MO, United States
| | - Franziska Pohl
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, United States
- *Correspondence: Kerry Kornfeld,
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4
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Pal A, Joshi T, Basu A, Gupta R. Management of Chronic Insomnia Using Cognitive Behavior Therapy for Insomnia (CBT-I) During COVID-19 Pandemic: Does One Shoe Fit All? SLEEP AND VIGILANCE 2022; 6:51-60. [PMID: 35313659 PMCID: PMC8929256 DOI: 10.1007/s41782-022-00197-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/21/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Purpose Insomnia is a highly prevalent disorder that is seen across all age groups causing significant morbidity to the patients. Its prevalence has further risen during COVID-19 pandemic. It is widely acknowledged that untreated insomnia can lead to significant health risks and socio-occupational dysfunction. Methods A narrative review was conducted following focused search of databases. Results Available guidelines mention two different approaches for the management of insomnia-pharmacological and non-pharmacological. Non-pharmacological therapies like multicomponent cognitive behavior therapy for insomnia (CBT-I) have been advocated for the management of acute as well as chronic insomnia in the literature as it has been found efficacious and useful. Multiple variants of CBT-I, e.g., digitally delivered CBT-I, brief CBT-I have been tested during pandemic owing to closure of clinics. However, there are certain issues to be considered while choosing CBT-I as therapy. For example, like other forms of psychotherapies, is there a need for assessing the candidature of patient before administering CBT-I; is CBT-I free of adverse effects as commonly thought; is CBT-I more efficacious than hypnotics; and at last, how to manage cases that are not candidate for CBT-I. Conclusion This narrative review addresses the scientific robustness of evidence for issues related to adherence, efficacy and adverse effects of non-pharmacological therapies. Available literature suggests that data related to adherence and efficacy of CBT-I suffer from methodological shortcomings and careful selection of patient is important for the successful therapy. At the same time, attempts have been made to shed light to the areas where CBT-I can be helpful in the management of insomnia.
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Affiliation(s)
- Arghya Pal
- Department of Psychiatry, All India Institute of Medical Sciences, Raibareli, 229405 India
| | - Tanmay Joshi
- Department of Psychiatry, All India Institute of Medical Sciences, Rishikesh, 249203 India
| | - Aniruddha Basu
- Department of Psychiatry, All India Institute of Medical Sciences, Kalyani, 741245 India
| | - Ravi Gupta
- Department of Psychiatry and Division of Sleep Medicine, All India Institute of Medical Sciences, Rishikesh, 249203 India
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5
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Wu D, Li R. Case Report: Long-Term Treatment and Follow-Up of Kleefstra Syndrome-2. Front Pediatr 2022; 10:881838. [PMID: 35685914 PMCID: PMC9172761 DOI: 10.3389/fped.2022.881838] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Mutations in the KMT2C gene can cause Kleefstra syndrome-2 (KLEFS2). CASE In this study, we analyzed the clinical, genetic testing, and 10-year follow-up data of a child with KLEFS2 treated at the Child Healthcare Department, Children's Hospital of Nanjing Medical University, Nanjing. The case of KLEFS2 presented feeding difficulty and developmental delay, both intervened by nutritional support and family rehabilitation. Obvious attention deficit hyperactivity disorder (ADHD) occurred in preschool and school-age children and was managed by behavioral and pharmaceutical interventions. CONCLUSION Features of KLEFS2 include feeding difficulty and developmental delays in an early age, as well as ADHD in preschool and school age. Satisfactory outcomes are not achieved in early nutritional support for correcting malnutrition and pharmaceutical intervention for relieving ADHD, but both measures can counter developmental delay.
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Affiliation(s)
- Dandan Wu
- Child Healthcare Department, Children's Hospital of Nanjing Medical University, Nanjing, China
| | - Rong Li
- Child Healthcare Department, Children's Hospital of Nanjing Medical University, Nanjing, China
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6
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Herrera P, Cauchi RJ. ACE and ACE2: insights from Drosophila and implications for COVID-19. Heliyon 2021; 7:e08555. [PMID: 34901515 PMCID: PMC8648576 DOI: 10.1016/j.heliyon.2021.e08555] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/21/2021] [Accepted: 12/02/2021] [Indexed: 12/27/2022] Open
Abstract
Angiotensin-converting enzyme (ACE) and its homologue ACE2 are key regulators of the renin-angiotensin system and thereby cardiovascular function through their zinc-metallopeptidase activity on vasoactive peptides. ACE2 also serves as the receptor for the cellular entry of various coronaviruses including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the coronavirus disease 2019 (COVID-19). The unprecedented scale of the COVID-19 pandemic has spurred the use of mammalian models to investigate the SARS-ACE2 relationship and knowledge gained from such research has accelerated development of vaccines and therapeutics. Recent studies have just started to underscore the utility of the fruit fly Drosophila melanogaster as a model system to study virus-host interactions and pathogenicity. Notably, the remarkable existence of catalytically functional ACE and ACE2 orthologues in Drosophila, discovered more than two decades ago, provides a unique opportunity for further developing this model organism to better understand COVID-19 in addition to identifying coronavirus preventative and therapeutic interventions targeting ACE2. Here, we review the studies that revealed crucial insights on the biochemistry and physiology of Ance and Acer, two out of the six Drosophila ACE family members with the greatest homology to human ACE and ACE2. We highlight shared in vivo functions outside of the renin-angiotensin system, which is not conserved in flies. Importantly, we identify knowledge gaps that can be filled by further research and outline ways that can raise Drosophila to a powerful model system to combat SARS-CoV-2 and its threatening vaccine-evading variants.
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Affiliation(s)
- Paul Herrera
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Ruben J. Cauchi
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
- Corresponding author.
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7
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Epiney DG, Salameh C, Cassidy D, Zhou LT, Kruithof J, Milutinović R, Andreani TS, Schirmer AE, Bolterstein E. Characterization of Stress Responses in a Drosophila Model of Werner Syndrome. Biomolecules 2021; 11:1868. [PMID: 34944512 PMCID: PMC8699552 DOI: 10.3390/biom11121868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/04/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022] Open
Abstract
As organisms age, their resistance to stress decreases while their risk of disease increases. This can be shown in patients with Werner syndrome (WS), which is a genetic disease characterized by accelerated aging along with increased risk of cancer and metabolic disease. WS is caused by mutations in WRN, a gene involved in DNA replication and repair. Recent research has shown that WRN mutations contribute to multiple hallmarks of aging including genomic instability, telomere attrition, and mitochondrial dysfunction. However, questions remain regarding the onset and effect of stress on early aging. We used a fly model of WS (WRNexoΔ) to investigate stress response during different life stages and found that stress sensitivity varies according to age and stressor. While larvae and young WRNexoΔ adults are not sensitive to exogenous oxidative stress, high antioxidant activity suggests high levels of endogenous oxidative stress. WRNexoΔ adults are sensitive to stress caused by elevated temperature and starvation suggesting abnormalities in energy storage and a possible link to metabolic dysfunction in WS patients. We also observed higher levels of sleep in aged WRNexoΔ adults suggesting an additional adaptive mechanism to protect against age-related stress. We suggest that stress response in WRNexoΔ is multifaceted and evokes a systemic physiological response to protect against cellular damage. These data further validate WRNexoΔ flies as a WS model with which to study mechanisms of early aging and provide a foundation for development of treatments for WS and similar diseases.
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Affiliation(s)
- Derek G. Epiney
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Charlotte Salameh
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Deirdre Cassidy
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Luhan T. Zhou
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Joshua Kruithof
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Rolan Milutinović
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Tomas S. Andreani
- Department of Neurobiology, Northwestern University, Evanston, IL 60208, USA;
| | - Aaron E. Schirmer
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
| | - Elyse Bolterstein
- Department of Biology, Northeastern Illinois University, Chicago, IL 60625, USA; (D.G.E.); (C.S.); (D.C.); (L.T.Z.); (J.K.); (R.M.); (A.E.S.)
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8
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Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Rescue Memory Defects in Drosophila-Expressing Alzheimer's Disease-Related Transgenes Independently of the Canonical Renin Angiotensin System. eNeuro 2020; 7:ENEURO.0235-20.2020. [PMID: 33060184 PMCID: PMC7768280 DOI: 10.1523/eneuro.0235-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 01/09/2023] Open
Abstract
Alzheimer's disease (AD) is a degenerative disorder that causes progressive memory and cognitive decline. Recently, studies have reported that inhibitors of the mammalian renin angiotensin system (RAS) result in a significant reduction in the incidence and progression of AD by unknown mechanisms. Here, we used a genetic and pharmacological approach to evaluate the beneficial effects of angiotensin converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) in Drosophila expressing AD-related transgenes. Importantly, while ACE orthologs have been identified in Drosophila, other RAS components are not conserved. We show that captopril, an ACE-I, and losartan, an ARB, can suppress a rough eye phenotype and brain cell death in flies expressing a mutant human C99 transgene. Captopril also significantly rescues memory defects in these flies. Similarly, both drugs reduce cell death in Drosophila expressing human Aβ42 and losartan significantly rescues memory deficits. However, neither drug affects production, accumulation or clearance of Aβ42 Importantly, neither drug rescued brain cell death in Drosophila expressing human Tau, suggesting that RAS inhibitors specifically target the amyloid pathway. Of note, we also observed reduced cell death and a complete rescue of memory deficits when we crossed a null mutation in Drosophila Acer into each transgenic line demonstrating that the target of captopril in Drosophila is Acer. Together, these studies demonstrate that captopril and losartan are able to modulate AD related phenotypes in the absence of the canonical RAS pathway and suggest that both drugs have additional targets that can be identified in Drosophila.
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9
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Meira E Cruz M, Miyazawa M, Gozal D. Putative contributions of circadian clock and sleep in the context of SARS-CoV-2 infection. Eur Respir J 2020; 55:2001023. [PMID: 32350105 PMCID: PMC7191115 DOI: 10.1183/13993003.01023-2020] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 04/20/2020] [Indexed: 12/20/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the aetiological agent of the pandemic coronavirus disease 2019 (COVID-19), is a newly found member of the Coronaviridae family, and is closely related to, albeit with important differences from, SARS-CoV [1]. It enters human cells through the binding of surface spike (S) glycoprotein with angiotensin-converting enzyme 2 (ACE2) [2–4]. The distal S1 subunit of the S protein is responsible for receptor binding, while the transmembrane S2 subunit mediates fusion between the viral envelope and the target cell membrane following proteolytic cleavage by specific cellular enzymes such as transmembrane serine protease 2 for S protein priming [5]. As it is likely that expression levels of ACE2 affect the efficiency of virus attachment and entry, as well as disease severity [6], and the interactions between viral S protein and ACE2 may directly cause lung injury [7], ACE2 may be a potential target of therapeutic and preventative interventions [8]. Circadian deregulation and poor or insufficient sleep may facilitate COVID-19 infection and severity https://bit.ly/2VUlIIJ
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Affiliation(s)
- Miguel Meira E Cruz
- Sleep Unit, Cardiovascular Center of University of Lisbon, Lisbon School of Medicine, Lisbon, Portugal
- Equal contributors
| | - Masaaki Miyazawa
- Dept of Immunology, Faculty of Medicine and Anti-Aging Center, Kindai University, Osaka, Japan
- Equal contributors
| | - David Gozal
- Dept of Child Health and the Child Health Research Institute, The University of Missouri School of Medicine, Columbia, MO, USA
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10
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Glover Z, Hodges MD, Dravecz N, Cameron J, Askwith H, Shirras A, Broughton SJ. Loss of angiotensin-converting enzyme-related (ACER) peptidase disrupts behavioural and metabolic responses to diet in Drosophila melanogaster. ACTA ACUST UNITED AC 2019; 222:jeb.194332. [PMID: 30940674 DOI: 10.1242/jeb.194332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 03/29/2019] [Indexed: 12/15/2022]
Abstract
Drosophila Acer (Angiotensin-converting enzyme-related) encodes a member of the angiotensin-converting enzyme (ACE) family of metallopeptidases that in mammals play roles in the endocrine regulation of blood homeostasis. ACE is also expressed in adipose tissue, where it is thought to play a role in metabolic regulation. Drosophila ACER is expressed in the adult fat body of the head and abdomen and is secreted into the haemolymph. Acer null mutants have previously been found to have reduced night-time sleep and greater sleep fragmentation. ACER may thus be part of a signalling system linking metabolism with sleep. To further understand the role of ACER in response to diet, we measured sleep and other nutrient-responsive phenotypes in Acer null flies under different dietary conditions. We show that loss of Acer disrupts the normal response of sleep to changes in nutrition. Other nutrient-sensitive phenotypes, including survival and glycogen storage, were also altered in the Acer mutant but lipid storage was not. Although the physiological substrate of the ACER peptidase has not been identified, an alteration of the normal nutrient-dependent control of Drosophila insulin-like peptide 5 protein in the Acer mutant suggests insulin/IGF-like signalling as a candidate pathway modulated by ACER in the nutrient-dependent control of sleep, survival and metabolism.
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Affiliation(s)
- Zoe Glover
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Matthew D Hodges
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Nikolett Dravecz
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Jack Cameron
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Helen Askwith
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Alan Shirras
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Susan J Broughton
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
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11
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Delbare SYN, Chow CY, Wolfner MF, Clark AG. Roles of Female and Male Genotype in Post-Mating Responses in Drosophila melanogaster. J Hered 2018; 108:740-753. [PMID: 29036644 DOI: 10.1093/jhered/esx081] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 09/25/2017] [Indexed: 12/18/2022] Open
Abstract
Mating induces a multitude of changes in female behavior, physiology, and gene expression. Interactions between female and male genotype lead to variation in post-mating phenotypes and reproductive success. So far, few female molecules responsible for these interactions have been identified. Here, we used Drosophila melanogaster from 5 geographically dispersed populations to investigate such female × male genotypic interactions at the female transcriptomic and phenotypic levels. Females from each line were singly-mated to males from the same 5 lines, for a total of 25 combinations. Reproductive output and refractoriness to re-mating were assayed in females from the 25 mating combinations. Female × male genotypic interactions resulted in significant differences in these post-mating phenotypes. To assess whether female × male genotypic interactions affect the female post-mating transcriptome, next-generation RNA sequencing was performed on virgin and mated females at 5 to 6 h post-mating. Seventy-seven genes showed strong variation in mating-induced expression changes in a female × male genotype-dependent manner. These genes were enriched for immune response and odorant-binding functions, and for expression exclusively in the head. Strikingly, variation in post-mating transcript levels of a gene encoding a spermathecal endopeptidase was correlated with short-term egg production. The transcriptional variation found in specific functional classes of genes might be a read-out of female × male compatibility at a molecular level. Understanding the roles these genes play in the female post-mating response will be crucial to better understand the evolution of post-mating responses and related conflicts between the sexes.
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Affiliation(s)
- Sofie Y N Delbare
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703
| | - Clement Y Chow
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703.,Department of Human Genetics, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703
| | - Andrew G Clark
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703
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Koemans TS, Kleefstra T, Chubak MC, Stone MH, Reijnders MRF, de Munnik S, Willemsen MH, Fenckova M, Stumpel CTRM, Bok LA, Sifuentes Saenz M, Byerly KA, Baughn LB, Stegmann APA, Pfundt R, Zhou H, van Bokhoven H, Schenck A, Kramer JM. Functional convergence of histone methyltransferases EHMT1 and KMT2C involved in intellectual disability and autism spectrum disorder. PLoS Genet 2017; 13:e1006864. [PMID: 29069077 PMCID: PMC5656305 DOI: 10.1371/journal.pgen.1006864] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 06/10/2017] [Indexed: 11/18/2022] Open
Abstract
Kleefstra syndrome, caused by haploinsufficiency of euchromatin histone methyltransferase 1 (EHMT1), is characterized by intellectual disability (ID), autism spectrum disorder (ASD), characteristic facial dysmorphisms, and other variable clinical features. In addition to EHMT1 mutations, de novo variants were reported in four additional genes (MBD5, SMARCB1, NR1I3, and KMT2C), in single individuals with clinical characteristics overlapping Kleefstra syndrome. Here, we present a novel cohort of five patients with de novo loss of function mutations affecting the histone methyltransferase KMT2C. Our clinical data delineates the KMT2C phenotypic spectrum and reinforces the phenotypic overlap with Kleefstra syndrome and other related ID disorders. To elucidate the common molecular basis of the neuropathology associated with mutations in KMT2C and EHMT1, we characterized the role of the Drosophila KMT2C ortholog, trithorax related (trr), in the nervous system. Similar to the Drosophila EHMT1 ortholog, G9a, trr is required in the mushroom body for short term memory. Trr ChIP-seq identified 3371 binding sites, mainly in the promoter of genes involved in neuronal processes. Transcriptional profiling of pan-neuronal trr knockdown and G9a null mutant fly heads identified 613 and 1123 misregulated genes, respectively. These gene sets show a significant overlap and are associated with nearly identical gene ontology enrichments. The majority of the observed biological convergence is derived from predicted indirect target genes. However, trr and G9a also have common direct targets, including the Drosophila ortholog of Arc (Arc1), a key regulator of synaptic plasticity. Our data highlight the clinical and molecular convergence between the KMT2 and EHMT protein families, which may contribute to a molecular network underlying a larger group of ID/ASD-related disorders. Neurodevelopmental disorders (NDDs) like intellectual disability (ID) and autism spectrum disorder (ASD) present an enormous challenge to affected individuals, their families, and society. Understanding the mechanisms underlying NDDs may lead to the development of targeted therapeutics, but this is complicated by the great clinical and genetic heterogeneity seen in patients. Mutations in hundreds of genes have been implicated in NDDs, giving rise to diverse clinical presentations. However, evidence suggests that many of these genes lie in common biological pathways, and mutations in genes that are involved in similar biological functions give rise to more similar clinical phenotypes. Here, we define a novel ID disorder with comorbid ASD (ID/ASD) caused by mutations in KMT2C. This disorder is defined by clinical features that overlap with a group of other disorders, including Kleefstra syndrome, which is caused by EHMT1 mutations. In the fruit fly, we show that the KMT2 and EHMT protein families regulate a highly converging set of biological processes. Both EHMT1 and KMT2C encode histone methyltransferases, which regulate gene transcription by modifying chromatin structure. Further understanding of the common gene regulatory networks associated with this group of ID- and ASD-related disorders may lead to the identification of novel therapeutic targets.
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Affiliation(s)
- Tom S. Koemans
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Tjitske Kleefstra
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Melissa C. Chubak
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
| | - Max H. Stone
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children’s Health Research Institute, London, Ontario, Canada
| | - Margot R. F. Reijnders
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Sonja de Munnik
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Marjolein H. Willemsen
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Michaela Fenckova
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Connie T. R. M. Stumpel
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, the Netherlands
| | - Levinus A. Bok
- Department of Pediatrics, Máxima Medical Centre, Veldhoven, The Netherlands
| | | | - Kyna A. Byerly
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Linda B. Baughn
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Alexander P. A. Stegmann
- Department of Clinical Genetics and School for Oncology & Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Huiqing Zhou
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Radboud Institute of Molecular Life Sciences, Nijmegen, The Netherlands
- Department of Molecular Developmental Biology, Radboud University, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
| | - Annette Schenck
- Department of Human Genetics, Radboudumc, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition, and Behaviour, Centre for Neuroscience, Nijmegen, The Netherlands
- * E-mail: (AS); (JMK)
| | - Jamie M. Kramer
- Department of Biology, Faculty of Science, Western University, London, Ontario, Canada
- Division of Genetics and Development, Children’s Health Research Institute, London, Ontario, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- * E-mail: (AS); (JMK)
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Elevated extension of longevity by cyclically heat stressing a set of recombinant inbred lines of Drosophila melanogaster throughout their adult life. Biogerontology 2016; 17:883-892. [DOI: 10.1007/s10522-016-9658-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/16/2016] [Indexed: 11/25/2022]
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Svetec N, Zhao L, Saelao P, Chiu JC, Begun DJ. Evidence that natural selection maintains genetic variation for sleep in Drosophila melanogaster. BMC Evol Biol 2015; 15:41. [PMID: 25887180 PMCID: PMC4374177 DOI: 10.1186/s12862-015-0316-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 02/24/2015] [Indexed: 11/10/2022] Open
Abstract
Background Drosophila melanogaster often shows correlations between latitude and phenotypic or genetic variation on different continents, which suggests local adaptation with respect to a heterogeneous environment. Previous phenotypic analyses of latitudinal clines have investigated mainly physiological, morphological, or life-history traits. Here, we studied latitudinal variation in sleep in D. melanogaster populations from North and Central America. In parallel, we used RNA-seq to identify interpopulation gene expression differences. Results We found that in D. melanogaster the average nighttime sleep bout duration exhibits a latitudinal cline such that sleep bouts of equatorial populations are roughly twice as long as those of temperate populations. Interestingly, this pattern of latitudinal variation is not observed for any daytime measure of activity or sleep. We also found evidence for geographic variation for sunrise anticipation. Our RNA-seq experiment carried out on heads from a low and high latitude population identified a large number of gene expression differences, most of which were time dependent. Differentially expressed genes were enriched in circadian regulated genes and enriched in genes potentially under spatially varying selection. Conclusion Our results are consistent with a mechanistic and selective decoupling of nighttime and daytime activity. Furthermore, the present study suggests that natural selection plays a major role in generating transcriptomic variation associated with circadian behaviors. Finally, we identified genomic variants plausibly causally associated with the observed behavioral and transcriptomic variation. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0316-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicolas Svetec
- Department of Evolution and Ecology, University of California, 3352 Storer Hall, One Shields Ave., Davis, CA, 95618, USA.
| | - Li Zhao
- Department of Evolution and Ecology, University of California, 3352 Storer Hall, One Shields Ave., Davis, CA, 95618, USA.
| | - Perot Saelao
- Department of Evolution and Ecology, University of California, 3352 Storer Hall, One Shields Ave., Davis, CA, 95618, USA.
| | - Joanna C Chiu
- Department of Entomology and Nematology, University of California, Davis, CA, USA.
| | - David J Begun
- Department of Evolution and Ecology, University of California, 3352 Storer Hall, One Shields Ave., Davis, CA, 95618, USA.
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Genetic dissection of sleep-metabolism interactions in the fruit fly. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2014; 201:869-77. [PMID: 25236355 DOI: 10.1007/s00359-014-0936-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Accepted: 08/16/2014] [Indexed: 10/24/2022]
Abstract
Dysregulation of sleep and metabolism has enormous health consequences. Sleep loss is linked to increased appetite and insulin insensitivity, and epidemiological studies link chronic sleep deprivation to obesity-related disorders including type II diabetes and cardiovascular disease. Interactions between sleep and metabolism involve the integration of signaling from brain regions regulating sleep, feeding, and metabolic function. Investigating the relationship between these processes provides a model to address more general questions of how the brain prioritizes homeostatically regulated behaviors. The availability of powerful genetic tools in the fruit fly, Drosophila melanogaster, allows for precise manipulation of neural function in freely behaving animals. There is a strong conservation of genes and neural circuit principles regulating sleep and metabolic function, and genetic screens in fruit flies have been effective in identifying novel regulators of these processes. Here, we review recent findings in the fruit fly that further our understanding of how the brain modulates sleep in accordance with metabolic state.
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Harrison C, Acharya KR. ACE for all - a molecular perspective. J Cell Commun Signal 2014; 8:195-210. [PMID: 25027949 PMCID: PMC4165820 DOI: 10.1007/s12079-014-0236-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/12/2014] [Indexed: 11/30/2022] Open
Abstract
Angiotensin-I converting enzyme (ACE, EC 3.4.15.1) is a zinc dependent dipeptidyl carboxypeptidase with an essential role in mammalian blood pressure regulation as part of the renin-angiotensin aldosterone system (RAAS). As such, it has long been targeted in the treatment of hypertension through the use of ACE inhibitors. Although ACE has been studied since the 1950s, only recently have the full range of functions of this enzyme begun to truly be appreciated. ACE homologues have been found in a host of other organisms, and are now known to be conserved in insects. Insect ACE homologues typically share over 30 % amino acid sequence identity with human ACE. Given that insects lack a mammalian type circulatory system, they must have crucial roles in other physiological processes. The first ACE crystal structures were reported during the last decade and have enabled these enzymes to be studied from an entirely different perspective. Here we review many of these key developments and the implications that they have had on our understanding of the diverse functions of these enzymes. Specifically, we consider how structural information is being used in the design of a new generation of ACE inhibitors with increased specificity, and how the structures of ACE homologues are related to their functions. The Anopheles gambiae genome is predicted to code for ten ACE homologues, more than any genome studied so far. We have modelled the active sites of some of these as yet uncharacterised enzymes to try and infer more about their potential roles at the molecular level.
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Affiliation(s)
- Charlotte Harrison
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY UK
| | - K. Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY UK
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Potdar S, Sheeba V. Lessons From Sleeping Flies: Insights fromDrosophila melanogasteron the Neuronal Circuitry and Importance of Sleep. J Neurogenet 2013; 27:23-42. [DOI: 10.3109/01677063.2013.791692] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Nusbaum MP, Blitz DM. Neuropeptide modulation of microcircuits. Curr Opin Neurobiol 2012; 22:592-601. [PMID: 22305485 DOI: 10.1016/j.conb.2012.01.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2012] [Accepted: 01/10/2012] [Indexed: 11/29/2022]
Abstract
Neuropeptides provide functional flexibility to microcircuits, their inputs and effectors by modulating presynaptic and postsynaptic properties and intrinsic currents. Recent studies have relied less on applied neuropeptide and more on their neural release. In rhythmically active microcircuits (central pattern generators, CPGs), recent studies show that neuropeptide modulation can enable particular activity patterns by organizing specific circuit motifs. Neuropeptides can also modify microcircuit output indirectly, by modulating circuit inputs. Recently elucidated consequences of neuropeptide modulation include changes in motor patterns and behavior, stabilization of rhythmic motor patterns and changes in CPG sensitivity to sensory input. One aspect of neuropeptide modulation that remains enigmatic is the presence of multiple peptide family members in the same nervous system and even the same neurons.
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Affiliation(s)
- Michael P Nusbaum
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6074, United States.
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Gimble JM, Sutton GM, Ptitsyn AA, Floyd ZE, Bunnell BA. Circadian rhythms in adipose tissue: an update. Curr Opin Clin Nutr Metab Care 2011; 14:554-61. [PMID: 21986477 DOI: 10.1097/mco.0b013e32834ad94b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Over the past decade, evidence has accumulated from basic science, clinical and epidemiological studies linking circadian mechanisms to adipose tissue biology and its related comorbidities, diabetes, metabolic syndrome and obesity. This review highlights recent in-vitro and in-vivo findings from murine, human and model organism studies. RECENT FINDINGS High-fat diets attenuate circadian mechanisms in murine adipose depots and these effects appear to be due to obesity rather than hyperglycemia. Deletion of circadian regulatory genes such as AMPK1 and nocturnin alter the circadian biology of adipose tissue. Unlike the mouse, circadian gene oscillation in human adipose tissue appears to be independent of BMI and diabetes status, suggesting that circadian mechanistic variation occurs across species. Clues for future directions in this emerging field come from studies of the hibernation and torpor state in mammals and infection models involving the Drosophila metabolic organ or 'fat body'. SUMMARY There is a growing consensus that circadian rhythms and metabolism are tightly regulated in adipose tissue and peripheral metabolic organs. Although central mechanisms are critical, autonomous clocks exist within the adipocytes themselves. Future circadian advances are likely to result from the studies of adipose tissue-specific gene deletions.
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Affiliation(s)
- Jeffrey M Gimble
- Stem Cell Biology Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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