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Melo MR, Wykes AD, Connelly AA, Bassi JK, Cheung SD, McDougall SJ, Menuet C, Bathgate RAD, Allen AM. Selective transduction and photoinhibition of pre-Bötzinger complex neurons that project to the facial nucleus in rats affects nasofacial activity. eLife 2023; 12:e85398. [PMID: 37772793 PMCID: PMC10653671 DOI: 10.7554/elife.85398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 09/28/2023] [Indexed: 09/30/2023] Open
Abstract
The pre-Bötzinger complex (preBötC), a key primary generator of the inspiratory breathing rhythm, contains neurons that project directly to facial nucleus (7n) motoneurons to coordinate orofacial and nasofacial activity. To further understand the identity of 7n-projecting preBötC neurons, we used a combination of optogenetic viral transgenic approaches to demonstrate that selective photoinhibition of these neurons affects mystacial pad activity, with minimal effects on breathing. These effects are altered by the type of anesthetic employed and also between anesthetized and conscious states. The population of 7n-projecting preBötC neurons we transduced consisted of both excitatory and inhibitory neurons that also send collaterals to multiple brainstem nuclei involved with the regulation of autonomic activity. We show that modulation of subgroups of preBötC neurons, based on their axonal projections, is a useful strategy to improve our understanding of the mechanisms that coordinate and integrate breathing with different motor and physiological behaviors. This is of fundamental importance, given that abnormal respiratory modulation of autonomic activity and orofacial behaviors have been associated with the development and progression of diseases.
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Affiliation(s)
- Mariana R Melo
- Department of Anatomy & Physiology, University of MelbourneMelbourneAustralia
| | - Alexander D Wykes
- Florey Institute of Neuroscience and Mental HealthMelbourneAustralia
- Florey Department of Neuroscience and Mental Health, University of MelbourneMelbourneAustralia
| | - Angela A Connelly
- Department of Anatomy & Physiology, University of MelbourneMelbourneAustralia
| | - Jaspreet K Bassi
- Department of Anatomy & Physiology, University of MelbourneMelbourneAustralia
| | - Shane D Cheung
- Biological Optical Microscopy Platform (BOMP) - University of MelbourneMelbourneAustralia
| | | | - Clément Menuet
- Institut de Neurobiologie de la Méditerrané, INMED UMR1249, INSERM, Aix-Marseille UniversitéMarseilleFrance
| | - Ross AD Bathgate
- Florey Institute of Neuroscience and Mental HealthMelbourneAustralia
- Department of Biochemistry and Molecular Biology, University of MelbourneMelbourneAustralia
| | - Andrew M Allen
- Department of Anatomy & Physiology, University of MelbourneMelbourneAustralia
- Florey Institute of Neuroscience and Mental HealthMelbourneAustralia
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Bassi JK, Connelly AA, Butler AG, Liu Y, Ghanbari A, Farmer DGS, Jenkins MW, Melo MR, McDougall SJ, Allen AM. Cover Image, Volume 530, Issue 17. J Comp Neurol 2022. [DOI: 10.1002/cne.25426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Bassi JK, Connelly AA, Butler AG, Liu Y, Ghanbari A, Farmer DGS, Jenkins MW, Melo MR, McDougall SJ, Allen AM. Analysis of the distribution of vagal afferent projections from different peripheral organs to the nucleus of the solitary tract in rats. J Comp Neurol 2022; 530:3072-3103. [PMID: 35988033 PMCID: PMC9804483 DOI: 10.1002/cne.25398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 07/26/2022] [Accepted: 08/02/2022] [Indexed: 01/05/2023]
Abstract
Anatomical tracing studies examining the vagal system can conflate details of sensory afferent and motor efferent neurons. Here, we used a serotype of adeno-associated virus that transports retrogradely and exhibits selective tropism for vagal afferents, to map their soma location and central termination sites within the nucleus of the solitary tract (NTS). We examined the vagal sensory afferents innervating the trachea, duodenum, stomach, or heart, and in some animals, from two organs concurrently. We observed no obvious somatotopy in the somata distribution within the nodose ganglion. The central termination patterns of afferents from different organs within the NTS overlap substantially. Convergence of vagal afferent inputs from different organs onto single NTS neurons is observed. Abdominal and thoracic afferents terminate throughout the NTS, including in the rostral NTS, where the 7th cranial nerve inputs are known to synapse. To address whether the axonal labeling produced by viral transduction is so widespread because it fills axons traveling to their targets, and not just terminal fields, we labeled pre and postsynaptic elements of vagal afferents in the NTS . Vagal afferents form multiple putative synapses as they course through the NTS, with each vagal afferent neuron distributing sensory signals to multiple second-order NTS neurons. We observe little selectivity between vagal afferents from different visceral targets and NTS neurons with common neurochemical phenotypes, with afferents from different organs making close appositions with the same NTS neuron. We conclude that specific viscerosensory information is distributed widely within the NTS and that the coding of this input is probably determined by the intrinsic properties and projections of the second-order neuron.
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Affiliation(s)
- Jaspreet K. Bassi
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Angela A. Connelly
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Andrew G. Butler
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Yehe Liu
- Department of Biomedical EngineeringCase Western Reserve UniversityClevelandOhioUSA
| | - Anahita Ghanbari
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia,Department of Queensland Brain InstituteThe University of QueenslandSt LuciaQueenslandAustralia
| | - David G. S. Farmer
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Michael W. Jenkins
- Department of Biomedical EngineeringCase Western Reserve UniversityClevelandOhioUSA
| | - Mariana R. Melo
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia
| | - Stuart J. McDougall
- Department of Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
| | - Andrew M. Allen
- Department of Anatomy and PhysiologyThe University of MelbourneParkvilleVictoriaAustralia,Department of Florey Institute of Neuroscience and Mental HealthThe University of MelbourneParkvilleVictoriaAustralia
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Booth LC, Yao ST, Korsak A, Farmer DGS, Hood SG, McCormick D, Boesley Q, Connelly AA, McDougall SJ, Korim WS, Guild SJ, Mastitskaya S, Le P, Teschemacher AG, Kasparov S, Ackland GL, Malpas SC, McAllen RM, Allen AM, May CN, Gourine AV. Selective optogenetic stimulation of efferent fibers in the vagus nerve of a large mammal. Brain Stimul 2020; 14:88-96. [PMID: 33217609 PMCID: PMC7836098 DOI: 10.1016/j.brs.2020.11.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/26/2020] [Accepted: 11/11/2020] [Indexed: 12/26/2022] Open
Abstract
Background Electrical stimulation applied to individual organs, peripheral nerves, or specific brain regions has been used to treat a range of medical conditions. In cardiovascular disease, autonomic dysfunction contributes to the disease progression and electrical stimulation of the vagus nerve has been pursued as a treatment for the purpose of restoring the autonomic balance. However, this approach lacks selectivity in activating function- and organ-specific vagal fibers and, despite promising results of many preclinical studies, has so far failed to translate into a clinical treatment of cardiovascular disease. Objective Here we report a successful application of optogenetics for selective stimulation of vagal efferent activity in a large animal model (sheep). Methods and results Twelve weeks after viral transduction of a subset of vagal motoneurons, strong axonal membrane expression of the excitatory light-sensitive ion channel ChIEF was achieved in the efferent projections innervating thoracic organs and reaching beyond the level of the diaphragm. Blue laser or LED light (>10 mW mm−2; 1 ms pulses) applied to the cervical vagus triggered precisely timed, strong bursts of efferent activity with evoked action potentials propagating at speeds of ∼6 m s−1. Conclusions These findings demonstrate that in species with a large, multi-fascicled vagus nerve, it is possible to stimulate a specific sub-population of efferent fibers using light at a site remote from the vector delivery, marking an important step towards eventual clinical use of optogenetic technology for autonomic neuromodulation. Described is a method of selective efferent vagus nerve stimulation using light. Vagal preganglionic neurons are targeted to express light-sensitive channels. Specific efferent VNS by light delivery to the cervical vagus is achieved in a large animal model. Demonstrates feasibility of using optogenetic technology for autonomic neuromodulation.
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Affiliation(s)
- Lindsea C Booth
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Song T Yao
- Florey Department of Neuroscience and Mental Health, MDHS, University of Melbourne, Melbourne, Australia
| | - Alla Korsak
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - David G S Farmer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia; Department of Physiology, The University of Melbourne, Melbourne, Australia
| | - Sally G Hood
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Daniel McCormick
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Quinn Boesley
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Angela A Connelly
- Department of Physiology, The University of Melbourne, Melbourne, Australia
| | - Stuart J McDougall
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Willian S Korim
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Sarah-Jane Guild
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Svetlana Mastitskaya
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Phuong Le
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Anja G Teschemacher
- Physiology, Neuroscience and Pharmacology, University of Bristol, Bristol, UK
| | - Sergey Kasparov
- Physiology, Neuroscience and Pharmacology, University of Bristol, Bristol, UK; Baltic Federal University, Kaliningrad, Russian Federation
| | - Gareth L Ackland
- Translational Medicine and Therapeutics, William Harvey Research Institute, Queen Mary University of London, London, UK
| | - Simon C Malpas
- Department of Physiology and Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Robin M McAllen
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Andrew M Allen
- Department of Physiology, The University of Melbourne, Melbourne, Australia
| | - Clive N May
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
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Menuet C, Connelly AA, Bassi JK, Melo MR, Le S, Kamar J, Kumar NN, McDougall SJ, McMullan S, Allen AM. PreBötzinger complex neurons drive respiratory modulation of blood pressure and heart rate. eLife 2020; 9:57288. [PMID: 32538785 PMCID: PMC7326498 DOI: 10.7554/elife.57288] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/14/2020] [Indexed: 12/14/2022] Open
Abstract
Heart rate and blood pressure oscillate in phase with respiratory activity. A component of these oscillations is generated centrally, with respiratory neurons entraining the activity of pre-sympathetic and parasympathetic cardiovascular neurons. Using a combination of optogenetic inhibition and excitation in vivo and in situ in rats, as well as neuronal tracing, we demonstrate that preBötzinger Complex (preBötC) neurons, which form the kernel for inspiratory rhythm generation, directly modulate cardiovascular activity. Specifically, inhibitory preBötC neurons modulate cardiac parasympathetic neuron activity whilst excitatory preBötC neurons modulate sympathetic vasomotor neuron activity, generating heart rate and blood pressure oscillations in phase with respiration. Our data reveal yet more functions entrained to the activity of the preBötC, with a role in generating cardiorespiratory oscillations. The findings have implications for cardiovascular pathologies, such as hypertension and heart failure, where respiratory entrainment of heart rate is diminished and respiratory entrainment of blood pressure exaggerated.
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Affiliation(s)
- Clément Menuet
- Department of Physiology, University of Melbourne, Victoria, Australia.,Institut de Neurobiologie de la Méditerranée, INMED UMR1249, INSERM, Aix-Marseille Université, Marseille, France
| | - Angela A Connelly
- Department of Physiology, University of Melbourne, Victoria, Australia
| | - Jaspreet K Bassi
- Department of Physiology, University of Melbourne, Victoria, Australia
| | - Mariana R Melo
- Department of Physiology, University of Melbourne, Victoria, Australia
| | - Sheng Le
- Faculty of Medicine & Health Sciences, Macquarie University, NSW, Australia
| | - Jessica Kamar
- Department of Physiology, University of Melbourne, Victoria, Australia
| | - Natasha N Kumar
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, NSW, Australia
| | - Stuart J McDougall
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia
| | - Simon McMullan
- Faculty of Medicine & Health Sciences, Macquarie University, NSW, Australia
| | - Andrew M Allen
- Department of Physiology, University of Melbourne, Victoria, Australia.,Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria, Australia
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Del Rosso de Melo M, Ong SJM, Connelly AA, Bassi JK, Colombari E, Allen AM. Involvement of Phox2B Neurons Located in the Commissural NTs with the Maintenance of Hypertension in SH Rats. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.742.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Sarah JM Ong
- PhysiologyThe University of MelbourneMelbourneAustralia
| | | | | | | | - Andrew M Allen
- PhysiologyThe University of MelbourneMelbourneAustralia
- Florey Institute of Neuroscience and Mental HealthUniversity of MelbourneMelbourneAustralia
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7
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Allen AM, Melo M, Connelly AA, Bassi JK, Colombari E. Examination of the Role of the Commissural Nucleus of the Solitary Tract in the Maintenance of Hypertension in the SHR. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.918.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Andrew Mark Allen
- PhysiologyUniversity of MelbourneParkvilleAustralia
- Florey Institute of Neuroscience and Mental HealthParkvilleAustralia
| | - Mariana Melo
- PhysiologyUniversity of MelbourneParkvilleAustralia
- Physiology and PathologySao Paolo State UniversityAraraquaraBrazil
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8
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Coulson R, Liew SH, Connelly AA, Yee NS, Deb S, Kumar B, Vargas AC, O'Toole SA, Parslow AC, Poh A, Putoczki T, Morrow RJ, Alorro M, Lazarus KA, Yeap EFW, Walton KL, Harrison CA, Hannan NJ, George AJ, Clyne CD, Ernst M, Allen AM, Chand AL. The angiotensin receptor blocker, Losartan, inhibits mammary tumor development and progression to invasive carcinoma. Oncotarget 2017; 8:18640-18656. [PMID: 28416734 PMCID: PMC5386636 DOI: 10.18632/oncotarget.15553] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 02/07/2017] [Indexed: 01/06/2023] Open
Abstract
Drugs that target the Renin-Angiotensin System (RAS) have recently come into focus for their potential utility as cancer treatments. The use of Angiotensin Receptor Blockers (ARBs) and Angiotensin-Converting Enzyme (ACE) Inhibitors (ACEIs) to manage hypertension in cancer patients is correlated with improved survival outcomes for renal, prostate, breast and small cell lung cancer. Previous studies demonstrate that the Angiotensin Receptor Type I (AT1R) is linked to breast cancer pathogenesis, with unbiased analysis of gene-expression studies identifying significant up-regulation of AGTR1, the gene encoding AT1R in ER+ve/HER2−ve tumors correlating with poor prognosis. However, there is no evidence, so far, of the functional contribution of AT1R to breast tumorigenesis. We explored the potential therapeutic benefit of ARB in a carcinogen-induced mouse model of breast cancer and clarified the mechanisms associated with its success. Mammary tumors were induced with 7,12-dimethylbenz[α]antracene (DMBA) and medroxyprogesterone acetate (MPA) in female wild type mice and the effects of the ARB, Losartan treatment assessed in a preventative setting (n = 15 per group). Tumor histopathology was characterised by immunohistochemistry, real-time qPCR to detect gene expression signatures, and tumor cytokine levels measured with quantitative bioplex assays. AT1R was detected with radiolabelled ligand binding assays in fresh frozen tumor samples. We showed that therapeutic inhibition of AT1R, with Losartan, resulted in a significant reduction in tumor burden; and no mammary tumor incidence in 20% of animals. We observed a significant reduction in tumor progression from DCIS to invasive cancer with Losartan treatment. This was associated with reduced tumor cell proliferation and a significant reduction in IL-6, pSTAT3 and TNFα levels. Analysis of tumor immune cell infiltrates, however, demonstrated no significant differences in the recruitment of lymphocytes or tumour-associated macrophages in Losartan or vehicle-treated mammary tumors. Analysis of AT1R expression with radiolabelled ligand binding assays in human breast cancer biopsies showed high AT1R levels in 30% of invasive ductal carcinomas analysed. Furthermore, analysis of the TCGA database identified that high AT1R expression to be associated with luminal breast cancer subtype. Our in vivo data and analysis of human invasive ductal carcinoma samples identify the AT1R is a potential therapeutic target in breast cancer, with the availability of a range of well-tolerated inhibitors currently used in clinics. We describe a novel signalling pathway critical in breast tumorigenesis, that may provide new therapeutic avenues to complement current treatments.
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Affiliation(s)
- Rhiannon Coulson
- Cancer Drug Discovery, Hudson's Institute of Medical Research, Clayton, VIC, Australia.,Translational Breast Cancer Research, Garvan Institute, Darlinghurst, Sydney, NSW, Australia
| | - Seng H Liew
- Department of Anatomy and Developmental Biology, Monash University, Clayton, VIC, Australia
| | | | - Nicholas S Yee
- Cancer and Inflammation Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
| | - Siddhartha Deb
- Anatomical Pathology, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
| | - Beena Kumar
- Anatomical Pathology, Monash Health, Clayton, VIC, Australia
| | - Ana C Vargas
- Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, NSW, Australia
| | - Sandra A O'Toole
- Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, NSW, Australia.,Translational Breast Cancer Research, Garvan Institute, Darlinghurst, Sydney, NSW, Australia.,Sydney Medical School, Sydney University, NSW, Australia
| | - Adam C Parslow
- Tumor Targeting Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.,School of Cancer Medicine, La Trobe University, Heidelberg, VIC, Australia
| | - Ashleigh Poh
- Inflammation Division, Walter and Eliza Hall Institute of Medical Research, VIC, Australia
| | - Tracy Putoczki
- Inflammation Division, Walter and Eliza Hall Institute of Medical Research, VIC, Australia
| | - Riley J Morrow
- Cancer and Inflammation Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
| | - Mariah Alorro
- Cancer and Inflammation Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
| | - Kyren A Lazarus
- Cancer Drug Discovery, Hudson's Institute of Medical Research, Clayton, VIC, Australia.,Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Evie F W Yeap
- Cancer Drug Discovery, Hudson's Institute of Medical Research, Clayton, VIC, Australia
| | - Kelly L Walton
- Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Craig A Harrison
- Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Natalie J Hannan
- Translational Obstetrics Group, Department of Obstetrics and Gynaecology, University of Melbourne, Mercy Hospital, Heidelberg, VIC, Australia
| | - Amee J George
- The ACRF Department of Cancer Biology and Therapeutics, John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Colin D Clyne
- Cancer Drug Discovery, Hudson's Institute of Medical Research, Clayton, VIC, Australia
| | - Matthias Ernst
- Cancer and Inflammation Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.,School of Cancer Medicine, La Trobe University, Heidelberg, VIC, Australia
| | - Andrew M Allen
- Department of Physiology, University of Melbourne, VIC, Australia
| | - Ashwini L Chand
- Cancer Drug Discovery, Hudson's Institute of Medical Research, Clayton, VIC, Australia.,Cancer and Inflammation Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia.,School of Cancer Medicine, La Trobe University, Heidelberg, VIC, Australia
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Carter DA, Guo H, Connelly AA, Bassi JK, Fong AY, Allen AM, McDougall SJ. Viscerosensory input drives angiotensin II type 1A receptor-expressing neurons in the solitary tract nucleus. Am J Physiol Regul Integr Comp Physiol 2017; 314:R282-R293. [PMID: 29118020 DOI: 10.1152/ajpregu.00290.2017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Homeostatic regulation of visceral organ function requires integrated processing of neural and neurohormonal sensory signals. The nucleus of the solitary tract (NTS) is the primary sensory nucleus for cranial visceral sensory afferents. Angiotensin II (ANG II) is known to modulate peripheral visceral reflexes, in part, by activating ANG II type 1A receptors (AT1AR) in the NTS. AT1AR-expressing NTS neurons occur throughout the NTS with a defined subnuclear distribution, and most of these neurons are depolarized by ANG II. In this study we determined whether AT1AR-expressing NTS neurons receive direct visceral sensory input, and whether this input is modulated by ANG II. Using AT1AR-GFP mice to make targeted whole cell recordings from AT1AR-expressing NTS neurons, we demonstrate that two-thirds (37 of 56) of AT1AR-expressing neurons receive direct excitatory, visceral sensory input. In half of the neurons tested (4 of 8) the excitatory visceral sensory input was significantly reduced by application of the transient receptor potential vallinoid type 1 receptor agonist, capsaicin, indicating AT1AR-expressing neurons can receive either C- or A-fiber-mediated input. Application of ANG II to a subset of second-order AT1AR-expressing neurons did not affect spontaneous, evoked, or asynchronous glutamate release from visceral sensory afferents. Thus it is unlikely that AT1AR-expressing viscerosensory neurons terminate on AT1AR-expressing NTS neurons. Our data suggest that ANG II is likely to modulate multiple visceral sensory modalities by altering the excitability of second-order AT1AR-expressing NTS neurons.
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Affiliation(s)
- D A Carter
- Department of Physiology, The University of Melbourne , Victoria , Australia
| | - H Guo
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne , Victoria , Australia
| | - A A Connelly
- Department of Physiology, The University of Melbourne , Victoria , Australia
| | - J K Bassi
- Department of Physiology, The University of Melbourne , Victoria , Australia
| | - A Y Fong
- Department of Physiology, The University of Melbourne , Victoria , Australia
| | - A M Allen
- Department of Physiology, The University of Melbourne , Victoria , Australia.,Florey Institute of Neuroscience and Mental Health, The University of Melbourne , Victoria , Australia
| | - S J McDougall
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne , Victoria , Australia
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10
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Carter DA, Choong YT, Connelly AA, Bassi JK, Hunter NO, Thongsepee N, Llewellyn-Smith IJ, Fong AY, McDougall SJ, Allen AM. Functional and neurochemical characterization of angiotensin type 1A receptor-expressing neurons in the nucleus of the solitary tract of the mouse. Am J Physiol Regul Integr Comp Physiol 2017; 313:R438-R449. [PMID: 28701322 DOI: 10.1152/ajpregu.00168.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/10/2017] [Accepted: 07/10/2017] [Indexed: 11/22/2022]
Abstract
Angiotensin II acts via two main receptors within the central nervous system, with the type 1A receptor (AT1AR) most widely expressed in adult neurons. Activation of the AT1R in the nucleus of the solitary tract (NTS), the principal nucleus receiving central synapses of viscerosensory afferents, modulates cardiovascular reflexes. Expression of the AT1R occurs in high density within the NTS of most mammals, including humans, but the fundamental electrophysiological and neurochemical characteristics of the AT1AR-expressing NTS neurons are not known. To address this, we have used a transgenic mouse, in which the AT1AR promoter drives expression of green fluorescent protein (GFP). Approximately one-third of AT1AR-expressing neurons express the catecholamine-synthetic enzyme tyrosine hydroxylase (TH), and a subpopulation of these stained for the transcription factor paired-like homeobox 2b (Phox2b). A third group, comprising approximately two-thirds of the AT1AR-expressing NTS neurons, showed Phox2b immunoreactivity alone. A fourth group in the ventral subnucleus expressed neither TH nor Phox2b. In whole cell recordings from slices in vitro, AT1AR-GFP neurons exhibited voltage-activated potassium currents, including the transient outward current and the M-type potassium current. In two different mouse strains, both AT1AR-GFP neurons and TH-GFP neurons showed similar AT1AR-mediated depolarizing responses to superfusion with angiotensin II. These data provide a comprehensive description of AT1AR-expressing neurons in the NTS and increase our understanding of the complex actions of this neuropeptide in the modulation of viscerosensory processing.
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Affiliation(s)
- D A Carter
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Y-T Choong
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - A A Connelly
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - J K Bassi
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - N O Hunter
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - N Thongsepee
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - I J Llewellyn-Smith
- Cardiovascular Medicine and Human Physiology, School of Medicine, Flinders University, Bedford Park, South Australia, Australia; and
| | - A Y Fong
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia
| | - S J McDougall
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - A M Allen
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia; .,Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, Victoria, Australia
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11
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Menuet C, Le S, Dempsey B, Connelly AA, Kamar JL, Jancovski N, Bassi JK, Walters K, Simms AE, Hammond A, Fong AY, Goodchild AK, McMullan S, Allen AM. Excessive Respiratory Modulation of Blood Pressure Triggers Hypertension. Cell Metab 2017; 25:739-748. [PMID: 28215844 DOI: 10.1016/j.cmet.2017.01.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 12/09/2016] [Accepted: 01/28/2017] [Indexed: 02/07/2023]
Abstract
The etiology of hypertension, the world's biggest killer, remains poorly understood, with treatments targeting the established symptom, not the cause. The development of hypertension involves increased sympathetic nerve activity that, in experimental hypertension, may be driven by excessive respiratory modulation. Using selective viral and cell lesion techniques, we identify adrenergic C1 neurons in the medulla oblongata as critical for respiratory-sympathetic entrainment and the development of experimental hypertension. We also show that a cohort of young, normotensive humans, selected for an exaggerated blood pressure response to exercise and thus increased hypertension risk, has enhanced respiratory-related blood pressure fluctuations. These studies pinpoint a specific neuronal target for ameliorating excessive sympathetic activity during the developmental phase of hypertension and identify a group of pre-hypertensive subjects that would benefit from targeting these cells.
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Affiliation(s)
- Clément Menuet
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Sheng Le
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Bowen Dempsey
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Angela A Connelly
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Jessica L Kamar
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Nikola Jancovski
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Jaspreet K Bassi
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Keryn Walters
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Annabel E Simms
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Andrew Hammond
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Angelina Y Fong
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Ann K Goodchild
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Simon McMullan
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Andrew M Allen
- Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia; Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC 3010, Australia.
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Jancovski N, Carter DA, Connelly AA, Stevens E, Bassi JK, Menuet C, Allen AM. Angiotensin type 1A receptor expression in C1 neurons of the rostral ventrolateral medulla contributes to the development of angiotensin-dependent hypertension. Exp Physiol 2014; 99:1597-610. [DOI: 10.1113/expphysiol.2014.082073] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Nikola Jancovski
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
| | - David A. Carter
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
| | - Angela A. Connelly
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
| | - Elyse Stevens
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
| | - Jaspreet K. Bassi
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
| | - Clement Menuet
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
| | - Andrew M. Allen
- Department of Physiology; University of Melbourne; Melbourne Victoria 3010 Australia
- Florey Institute of Neuroscience and Mental Health; University of Melbourne; Melbourne Victoria 3010 Australia
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13
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Gaspar YM, McKenna JA, McGinness BS, Hinch J, Poon S, Connelly AA, Anderson MA, Heath RL. Field resistance to Fusarium oxysporum and Verticillium dahliae in transgenic cotton expressing the plant defensin NaD1. J Exp Bot 2014; 65:1541-50. [PMID: 24502957 PMCID: PMC3967090 DOI: 10.1093/jxb/eru021] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The plant defensin NaD1, from Nicotiana alata, has potent antifungal activity against a range of filamentous fungi including the two important cotton pathogens, Fusarium oxysporum f. sp. vasinfectum (Fov) and Verticillium dahliae. Transgenic cotton plants expressing NaD1 were produced and plants from three events were selected for further characterization. Homozygous plants were assessed in greenhouse bioassays for resistance to Fov. One line (D1) was selected for field trial testing over three growing seasons in soils naturally infested with Fov and over two seasons in soils naturally infested with V. dahliae. In the field trials with Fov-infested soil, line D1 had 2-3-times the survival rate, a higher tolerance to Fov (higher disease rank), and a 2-4-fold increase in lint yield compared to the non-transgenic Coker control. When transgenic line D1 was planted in V. dahliae-infested soil, plants had a higher tolerance to Verticillium wilt and up to a 2-fold increase in lint yield compared to the non-transgenic Coker control. Line D1 did not exhibit any detrimental agronomic features compared to the parent Coker control when plants were grown in non-diseased soil. This study demonstrated that the expression of NaD1 in transgenic cotton plants can provide substantial resistance to two economically important fungal pathogens.
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Affiliation(s)
- Yolanda M. Gaspar
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Hexima Limited, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
| | - James A. McKenna
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Hexima Limited, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Bruce S. McGinness
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jillian Hinch
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Simon Poon
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
- Hexima Limited, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Angela A. Connelly
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Marilyn A. Anderson
- Hexima Limited, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Robyn L. Heath
- Hexima Limited, School of Botany, The University of Melbourne, Melbourne, Victoria 3010, Australia
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Lay FT, Poon S, McKenna JA, Connelly AA, Barbeta BL, McGinness BS, Fox JL, Daly NL, Craik DJ, Heath RL, Anderson MA. The C-terminal propeptide of a plant defensin confers cytoprotective and subcellular targeting functions. BMC Plant Biol 2014; 14:41. [PMID: 24495600 PMCID: PMC3922462 DOI: 10.1186/1471-2229-14-41] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 01/28/2014] [Indexed: 05/07/2023]
Abstract
BACKGROUND Plant defensins are small (45-54 amino acids), basic, cysteine-rich proteins that have a major role in innate immunity in plants. Many defensins are potent antifungal molecules and are being evaluated for their potential to create crop plants with sustainable disease resistance. Defensins are produced as precursor molecules which are directed into the secretory pathway and are divided into two classes based on the absence (class I) or presence (class II) of an acidic C-terminal propeptide (CTPP) of about 33 amino acids. The function of this CTPP had not been defined. RESULTS By transgenically expressing the class II plant defensin NaD1 with and without its cognate CTPP we have demonstrated that NaD1 is phytotoxic to cotton plants when expressed without its CTPP. Transgenic cotton plants expressing constructs encoding the NaD1 precursor with the CTPP had the same morphology as non-transgenic plants but expression of NaD1 without the CTPP led to plants that were stunted, had crinkled leaves and were less viable. Immunofluorescence microscopy and transient expression of a green fluorescent protein (GFP)-CTPP chimera were used to confirm that the CTPP is sufficient for vacuolar targeting. Finally circular dichroism and NMR spectroscopy were used to show that the CTPP adopts a helical confirmation. CONCLUSIONS In this report we have described the role of the CTPP on NaD1, a class II defensin from Nicotiana alata flowers. The CTPP of NaD1 is sufficient for vacuolar targeting and plays an important role in detoxification of the defensin as it moves through the plant secretory pathway. This work may have important implications for the use of defensins for disease protection in transgenic crops.
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Affiliation(s)
- Fung T Lay
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia
| | - Simon Poon
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia
- School of Botany, University of Melbourne, Melbourne VIC 3010, Australia
| | - James A McKenna
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia
- School of Botany, University of Melbourne, Melbourne VIC 3010, Australia
| | - Angela A Connelly
- School of Botany, University of Melbourne, Melbourne VIC 3010, Australia
| | - Barbara L Barbeta
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia
| | - Bruce S McGinness
- School of Botany, University of Melbourne, Melbourne VIC 3010, Australia
| | - Jennifer L Fox
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia
- School of Botany, University of Melbourne, Melbourne VIC 3010, Australia
| | - Norelle L Daly
- Institute for Molecular Bioscience, University of Queensland, Brisbane QLD 4072, Australia
| | - David J Craik
- Institute for Molecular Bioscience, University of Queensland, Brisbane QLD 4072, Australia
| | - Robyn L Heath
- School of Botany, University of Melbourne, Melbourne VIC 3010, Australia
| | - Marilyn A Anderson
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne VIC 3086, Australia
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15
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Sugiana C, Dunning CJ, Lazarou M, McKenzie M, Connelly AA, Fletcher JM, Thorburn DR, Ryan MT. Mutations in the assembly factor NDUFAF1 are a novel cause of mitochondrial Complex I deficiency. Mitochondrion 2006. [DOI: 10.1016/j.mito.2006.08.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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