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Lu R, Li Y, Xu A, King B, Ruan KH. Reprogramming Megakaryocytes for Controlled Release of Platelet-like Particles Carrying a Single-Chain Thromboxane A 2 Receptor-G-Protein Complex with Therapeutic Potential. Cells 2023; 12:2775. [PMID: 38132095 PMCID: PMC10741393 DOI: 10.3390/cells12242775] [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: 08/03/2023] [Revised: 12/01/2023] [Accepted: 12/02/2023] [Indexed: 12/23/2023] Open
Abstract
In this study, we reported that novel single-chain fusion proteins linking thromboxane A2 (TXA2) receptor (TP) to a selected G-protein α-subunit q (SC-TP-Gαq) or to α-subunit s (SC-TP-Gαs) could be stably expressed in megakaryocytes (MKs). We tested the MK-released platelet-linked particles (PLPs) to be used as a vehicle to deliver the overexpressed SC-TP-Gαq or the SC-TP-Gαs to regulate human platelet function. To understand how the single-chain TP-Gα fusion proteins could regulate opposite platelet activities by an identical ligand TXA2, we tested their dual functions-binding to ligands and directly linking to different signaling pathways within a single polypeptide chain-using a 3D structural model. The immature MKs were cultured and transfected with cDNAs constructed from structural models of the individual SC-TP-Gαq and SC-TP-Gαs, respectively. After transient expression was identified, the immature MKs stably expressing SC-TP-Gαq or SC-TP-Gαs (stable cell lines) were selected. The stable cell lines were induced into mature MKs which released PLPs. Western blot analysis confirmed that the released PLPs were carrying the recombinant SC-TP-Gαq or SC-TP-Gαs. Flow cytometry analysis showed that the PLPs carrying SC-TP-Gαq were able to perform the activity by promoting platelet aggregation. In contrast, PLPs carrying SC-TP-Gαs reversed Gq to Gs signaling to inhibit platelet aggregation. This is the first time demonstrating that SC-TP-Gαq and SC-TP-Gαs were successfully overexpressed in MK cells and released as PLPs with proper folding and programmed biological activities. This bio-engineering led to the formation of two sets of biologically active PLP forms mediating calcium and cAMP signaling, respectively. As a result, these PLPs are able to bind to identical endogenous TXA2 with opposite activities, inhibiting and promoting platelet aggregation as reprogrammed for therapeutic process. Results also demonstrated that the nucleus-free PLPs could be used to deliver recombinant membrane-bound GPCRs to regulate cellular activity in general.
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Affiliation(s)
| | | | | | | | - Ke-He Ruan
- The Center for Experimental Therapeutics and Pharmacoinformatics, Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, USA; (R.L.); (Y.L.); (A.X.); (B.K.)
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2
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Seckler JM, Getsy PM, May WJ, Gaston B, Baby SM, Lewis THJ, Bates JN, Lewis SJ. Hypoxia releases S-nitrosocysteine from carotid body glomus cells-relevance to expression of the hypoxic ventilatory response. Front Pharmacol 2023; 14:1250154. [PMID: 37886129 PMCID: PMC10598756 DOI: 10.3389/fphar.2023.1250154] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/13/2023] [Indexed: 10/28/2023] Open
Abstract
We have provided indirect pharmacological evidence that hypoxia may trigger release of the S-nitrosothiol, S-nitroso-L-cysteine (L-CSNO), from primary carotid body glomus cells (PGCs) of rats that then activates chemosensory afferents of the carotid sinus nerve to elicit the hypoxic ventilatory response (HVR). The objective of this study was to provide direct evidence, using our capacitive S-nitrosothiol sensor, that L-CSNO is stored and released from PGCs extracted from male Sprague Dawley rat carotid bodies, and thus further pharmacological evidence for the role of S-nitrosothiols in mediating the HVR. Key findings of this study were that 1) lysates of PGCs contained an S-nitrosothiol with physico-chemical properties similar to L-CSNO rather than S-nitroso-L-glutathione (L-GSNO), 2) exposure of PGCs to a hypoxic challenge caused a significant increase in S-nitrosothiol concentrations in the perfusate to levels approaching 100 fM via mechanisms that required extracellular Ca2+, 3) the dose-dependent increases in minute ventilation elicited by arterial injections of L-CSNO and L-GSNO were likely due to activation of small diameter unmyelinated C-fiber carotid body chemoafferents, 4) L-CSNO, but not L-GSNO, responses were markedly reduced in rats receiving continuous infusion (10 μmol/kg/min, IV) of both S-methyl-L-cysteine (L-SMC) and S-ethyl-L-cysteine (L-SEC), 5) ventilatory responses to hypoxic gas challenge (10% O2, 90% N2) were also due to the activation of small diameter unmyelinated C-fiber carotid body chemoafferents, and 6) the HVR was markedly diminished in rats receiving L-SMC plus L-SEC. This data provides evidence that rat PGCs synthesize an S-nitrosothiol with similar properties to L-CSNO that is released in an extracellular Ca2+-dependent manner by hypoxia.
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Affiliation(s)
- James M. Seckler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Paulina M. Getsy
- Departments of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
| | - Walter J. May
- Department of Pediatrics, University of Virginia, Charlottesville, Virginia, United States
| | - Benjamin Gaston
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, United States
| | | | - Tristan H. J. Lewis
- Departments of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
| | - James N. Bates
- Department of Anesthesia, University of Iowa, Iowa City, IA, United States
| | - Stephen J. Lewis
- Departments of Pediatrics, Case Western Reserve University, Cleveland, OH, United States
- Departments of Pharmacology, Case Western Reserve University, Cleveland, OH, United States
- Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH, United States
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3
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Aldossary HS, Nieves DJ, Kavanagh DM, Owen D, Ray CJ, Kumar P, Coney AM, Holmes AP. Analyzing Angiotensin II Receptor Type 1 Clustering in PC12 Cells in Response to Hypoxia Using Direct Stochastic Optical Reconstruction Microscopy (dSTORM). Adv Exp Med Biol 2023; 1427:175-184. [PMID: 37322348 DOI: 10.1007/978-3-031-32371-3_19] [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] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Angiotensin II (Ang II) is a hormone that plays a major role in maintaining homeostasis. The Ang II receptor type 1 (AT1R) is expressed in acute O2 sensitive cells, including carotid body (CB) type I cells and pheochromocytoma 12 (PC12) cells, and Ang II increases cell activity. While a functional role for Ang II and AT1Rs in increasing the activity of O2 sensitive cells has been established, the nanoscale distribution of AT1Rs has not. Furthermore, it is not known how exposure to hypoxia may alter the single-molecule arrangement and clustering of AT1Rs. In this study, the AT1R nanoscale distribution under control normoxic conditions in PC12 cells was determined using direct stochastic optical reconstruction microscopy (dSTORM). AT1Rs were arranged in distinct clusters with measurable parameters. Across the entire cell surface there averaged approximately 3 AT1R clusters/μm2 of cell membrane. Cluster area varied in size ranging from 1.1 × 10-4 to 3.9 × 10-2 μm2. Twenty-four hours of exposure to hypoxia (1% O2) altered clustering of AT1Rs, with notable increases in the maximum cluster area, suggestive of an increase in supercluster formation. These observations could aid in understanding mechanisms underlying augmented Ang II sensitivity in O2 sensitive cells in response to sustained hypoxia.
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Affiliation(s)
- Hayyaf S Aldossary
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK.
- College of Medicine, Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
| | - Daniel J Nieves
- Institute of Immunology and Immunotherapy and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK
| | | | - Dylan Owen
- School of Mathematics, University of Birmingham, Birmingham, UK
| | - Clare J Ray
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Prem Kumar
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Andrew M Coney
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK.
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4
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Lorigo M, Cairrao E. UV-B filter octylmethoxycinnamate-induced vascular endothelial disruption on rat aorta: In silico and in vitro approach. Chemosphere 2022; 307:135807. [PMID: 35931261 DOI: 10.1016/j.chemosphere.2022.135807] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 07/07/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Throughout human life, an extensive and varied range of emerging environmental contaminants, called endocrine disruptors (EDCs), cause adverse health effects, including in the cardiovascular (CV) system. Cardiovascular diseases (CVD) are worryingly one of the leading causes of all mortality and mobility worldwide. The UV-B filter octylmethoxycinnamate (also designated octinoxate, or ethylhexyl methoxycinnamate (CAS number: 5466-77-3)) is an EDC widely present in all personal care products. However, to date, there are no studies evaluating the OMC-induced effects on vasculature using animal models to improve human cardiovascular health. This work analysed the effects of OMC on rat aorta vasculature and explored the modes of action implicated in these effects. Our results indicated that OMC relaxes the rat aorta by endothelium-dependent mechanisms through the signaling pathways of cyclic nucleotides and by endothelium-independent mechanisms involving inhibition of L-Type voltage-operated Ca2+ channels (L-Type VOCC). Overall, OMC toxicity on rat aorta may produce hypotension via vasodilation due to excessive NO release and blockade of L-Type VOCC. Moreover, the OMC-induced endothelial dysfunction may also occur by promoting the endothelial release of endothelin-1. Therefore, our findings demonstrate that exposure to OMC alters the reactivity of the rat aorta and highlight that long-term OMC exposure may increase the risk of human CV diseases.
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Affiliation(s)
- Margarida Lorigo
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506, Covilhã, Portugal; FCS - UBI, Faculty of Health Sciences, University of Beira Interior, 6200-506, Covilhã, Portugal; C4-UBI, Cloud Computing Competence Centre, University of Beira Interior, 6200-501, Covilhã, Portugal.
| | - Elisa Cairrao
- CICS-UBI, Health Sciences Research Centre, University of Beira Interior, 6200-506, Covilhã, Portugal; FCS - UBI, Faculty of Health Sciences, University of Beira Interior, 6200-506, Covilhã, Portugal; C4-UBI, Cloud Computing Competence Centre, University of Beira Interior, 6200-501, Covilhã, Portugal.
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5
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Luo Z, Tian M, Yang G, Tan Q, Chen Y, Li G, Zhang Q, Li Y, Wan P, Wu J. Hypoxia signaling in human health and diseases: implications and prospects for therapeutics. Signal Transduct Target Ther 2022; 7:218. [PMID: 35798726 DOI: 10.1038/s41392-022-01080-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 06/17/2022] [Accepted: 06/23/2022] [Indexed: 02/07/2023] Open
Abstract
Molecular oxygen (O2) is essential for most biological reactions in mammalian cells. When the intracellular oxygen content decreases, it is called hypoxia. The process of hypoxia is linked to several biological processes, including pathogenic microbe infection, metabolic adaptation, cancer, acute and chronic diseases, and other stress responses. The mechanism underlying cells respond to oxygen changes to mediate subsequent signal response is the central question during hypoxia. Hypoxia-inducible factors (HIFs) sense hypoxia to regulate the expressions of a series of downstream genes expression, which participate in multiple processes including cell metabolism, cell growth/death, cell proliferation, glycolysis, immune response, microbe infection, tumorigenesis, and metastasis. Importantly, hypoxia signaling also interacts with other cellular pathways, such as phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling, nuclear factor kappa-B (NF-κB) pathway, extracellular signal-regulated kinases (ERK) signaling, and endoplasmic reticulum (ER) stress. This paper systematically reviews the mechanisms of hypoxia signaling activation, the control of HIF signaling, and the function of HIF signaling in human health and diseases. In addition, the therapeutic targets involved in HIF signaling to balance health and diseases are summarized and highlighted, which would provide novel strategies for the design and development of therapeutic drugs.
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6
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Li C, Zhao B, Zhao C, Huang L, Liu Y. Metabotropic Glutamate Receptors 1 Regulates Rat Carotid Body Response to Acute Hypoxia via Presynaptic Mechanism. Front Neurosci 2021; 15:741214. [PMID: 34675769 PMCID: PMC8524001 DOI: 10.3389/fnins.2021.741214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 07/21/2021] [Accepted: 09/07/2021] [Indexed: 12/20/2022] Open
Abstract
Background: The carotid body (CB) plays a critical role in oxygen sensing; however, the role of glutamatergic signaling in the CB response to hypoxia remains uncertain. We previously found that functional multiple glutamate transporters and inotropic glutamate receptors (iGluRs) are expressed in the CB. The aim of this present research is to investigate the expression of group I metabotropic glutamate receptors (mGluRs) (mGluR1 and 5) in the CB and its physiological function in rat CB response to acute hypoxia. Methods: RT-PCR and immunostaining were conducted to examine the mRNA and protein expression of group I mGluRs in the human and rat CB. Immunofluorescence staining was performed to examine the cellular localization of mGluR1 in the rat CB. In vitro carotid sinus nerve (CSN) discharge recording was performed to detect the physiological function of mGluR1 in CB response to acute hypoxia. Results: We found that (1) mRNAs of mGluR1 and 5 were both expressed in the human and rat CB. (2) mGluR1 protein rather than mGluR5 protein was present in rat CB. (3) mGluR1 was distributed in type I cells of rat CB. (4) Activation of mGluR1 inhibited the hypoxia-induced enhancement of CSN activity (CSNA), as well as prolonged the latency time of CB response to hypoxia. (5) The inhibitory effect of mGluR1 activation on rat CB response to hypoxia could be blocked by GABAB receptor antagonist. Conclusion: Our findings reveal that mGluR1 in CB plays a presynaptic feedback inhibition on rat CB response to hypoxia.
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Affiliation(s)
- Chaohong Li
- Henan Key Laboratory of Neural Regeneration and Repairment, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Baosheng Zhao
- Department of Thoracic Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Chenlu Zhao
- Henan Key Laboratory of Neural Regeneration and Repairment, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Lu Huang
- Henan Key Laboratory of Neural Regeneration and Repairment, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
| | - Yuzhen Liu
- Henan Key Laboratory of Neural Regeneration and Repairment, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, China
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7
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Tenzing N, van Patot MT, Liu H, Xu Q, Liu J, Wang Z, Wang Y, Wuren T, Ge RL. Identification of a miRNA-mRNA Regulatory Networks in Placental Tissue Associated With Tibetan High Altitude Adaptation. Front Genet 2021; 12:671119. [PMID: 34567059 PMCID: PMC8460760 DOI: 10.3389/fgene.2021.671119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 02/23/2021] [Accepted: 07/30/2021] [Indexed: 11/15/2022] Open
Abstract
The Tibetan population has lived and successfully reproduced at high altitude for many generations. Studies have shown that Tibetans have various mechanisms for protection against high-altitude hypoxia, which are probably due, at least in part, to placental adaptation. However, comprehensive in silico analyses of placentas in Tibetans are lacking. We performed a microarray-based comparative transcriptome analysis of 10 Tibetan women from Yushu, Qinghai, CHN (∼3,780 m) and 10 European women living in Leadville, CO, United States (∼3,100 m) for less than three generations. Expression of HIF-1α, STAT3, EGFR, HSP5A, XBP1, and ATF6A mRNA was less in the Tibetan placentas as compared with European placentas. A total of 38 miRNAs were involved in regulating these genes. Differentially expressed genes were enriched for HIF1α signaling pathways, protein processing in the endoplasmic reticulum, PI3K-AKT signaling pathways, and MAPK signaling pathways. Based on the transcriptome profiles, the Tibetan population was distinct from the European population; placental tissues from the Tibetan population are lacking hypoxic responses, and “passivation” occurs in response to hypoxic stress. These results provide insights into the molecular signature of adaptation to high altitudes in these two populations.
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Affiliation(s)
- Noryung Tenzing
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | | | - Huifang Liu
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Qiying Xu
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Juanli Liu
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Qinghai Provincial People's Hospital, Xining, China
| | - Zhuoya Wang
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Yanjun Wang
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China.,Clinical Department, Qinghai University Affiliated Hospital, Xining, China
| | - Tana Wuren
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, China.,Key Laboratory for Application of High Altitude Medicine, Qinghai University, Xining, China
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8
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Swiderska A, Coney AM, Alzahrani AA, Aldossary HS, Batis N, Ray CJ, Kumar P, Holmes AP. Mitochondrial Succinate Metabolism and Reactive Oxygen Species Are Important but Not Essential for Eliciting Carotid Body and Ventilatory Responses to Hypoxia in the Rat. Antioxidants (Basel) 2021; 10:840. [PMID: 34070267 DOI: 10.3390/antiox10060840] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/18/2021] [Accepted: 05/21/2021] [Indexed: 01/31/2023] Open
Abstract
Reflex increases in breathing in response to acute hypoxia are dependent on activation of the carotid body (CB)—A specialised peripheral chemoreceptor. Central to CB O2-sensing is their unique mitochondria but the link between mitochondrial inhibition and cellular stimulation is unresolved. The objective of this study was to evaluate if ex vivo intact CB nerve activity and in vivo whole body ventilatory responses to hypoxia were modified by alterations in succinate metabolism and mitochondrial ROS (mitoROS) generation in the rat. Application of diethyl succinate (DESucc) caused concentration-dependent increases in chemoafferent frequency measuring approximately 10–30% of that induced by severe hypoxia. Inhibition of mitochondrial succinate metabolism by dimethyl malonate (DMM) evoked basal excitation and attenuated the rise in chemoafferent activity in hypoxia. However, approximately 50% of the response to hypoxia was preserved. MitoTEMPO (MitoT) and 10-(6′-plastoquinonyl) decyltriphenylphosphonium (SKQ1) (mitochondrial antioxidants) decreased chemoafferent activity in hypoxia by approximately 20–50%. In awake animals, MitoT and SKQ1 attenuated the rise in respiratory frequency during hypoxia, and SKQ1 also significantly blunted the overall hypoxic ventilatory response (HVR) by approximately 20%. Thus, whilst the data support a role for succinate and mitoROS in CB and whole body O2-sensing in the rat, they are not the sole mediators. Treatment of the CB with mitochondrial selective antioxidants may offer a new approach for treating CB-related cardiovascular–respiratory disorders.
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9
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Stocco E, Sfriso MM, Borile G, Contran M, Barbon S, Romanato F, Macchi V, Guidolin D, De Caro R, Porzionato A. Experimental Evidence of A 2A-D 2 Receptor-Receptor Interactions in the Rat and Human Carotid Body. Front Physiol 2021; 12:645723. [PMID: 33935801 PMCID: PMC8082109 DOI: 10.3389/fphys.2021.645723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 12/23/2020] [Accepted: 03/09/2021] [Indexed: 12/26/2022] Open
Abstract
Adenosine A2A receptors (A2AR) and dopamine D2 receptors (D2R) are known to be involved in the physiological response to hypoxia, and their expression/activity may be modulated by chronic sustained or intermittent hypoxia. To date, A2AR and D2R can form transient physical receptor–receptor interactions (RRIs) giving rise to a dynamic equilibrium able to influence ligand binding and signaling, as demonstrated in different native tissues and transfected mammalian cell systems. Given the presence of A2AR and D2R in type I cells, type II cells, and afferent nerve terminals of the carotid body (CB), the aim of this work was to demonstrate here, for the first time, the existence of A2AR–D2R heterodimers by in situ proximity ligation assay (PLA). Our data by PLA analysis and tyrosine hydroxylase/S100 colocalization indicated the formation of A2AR–D2R heterodimers in type I and II cells of the CB; the presence of A2AR–D2R heterodimers also in afferent terminals is also suggested by PLA signal distribution. RRIs could play a role in CB dynamic modifications and plasticity in response to development/aging and environmental stimuli, including chronic intermittent/sustained hypoxia. Exploring other RRIs will allow for a broad comprehension of the regulative mechanisms these interactions preside over, with also possible clinical implications.
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Affiliation(s)
- Elena Stocco
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Maria Martina Sfriso
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Giulia Borile
- Department of Physics and Astronomy "G. Galilei," University of Padova, Padua, Italy.,Institute of Pediatric Research Città della Speranza, Padua, Italy
| | - Martina Contran
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Silvia Barbon
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Filippo Romanato
- Department of Physics and Astronomy "G. Galilei," University of Padova, Padua, Italy.,Institute of Pediatric Research Città della Speranza, Padua, Italy
| | - Veronica Macchi
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Diego Guidolin
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Raffaele De Caro
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
| | - Andrea Porzionato
- Department of Neuroscience, Institute of Human Anatomy, University of Padova, Padua, Italy
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10
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Alzahrani AA, Cao LL, Aldossary HS, Nathanael D, Fu J, Ray CJ, Brain KL, Kumar P, Coney AM, Holmes AP. β-Adrenoceptor blockade prevents carotid body hyperactivity and elevated vascular sympathetic nerve density induced by chronic intermittent hypoxia. Pflugers Arch 2021; 473:37-51. [PMID: 33210151 PMCID: PMC7782391 DOI: 10.1007/s00424-020-02492-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/26/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022]
Abstract
Carotid body (CB) hyperactivity promotes hypertension in response to chronic intermittent hypoxia (CIH). The plasma concentration of adrenaline is reported to be elevated in CIH and our previous work suggests that adrenaline directly activates the CB. However, a role for chronic adrenergic stimulation in mediating CB hyperactivity is currently unknown. This study evaluated whether beta-blocker treatment with propranolol (Prop) prevented the development of CB hyperactivity, vascular sympathetic nerve growth and hypertension caused by CIH. Adult male Wistar rats were assigned into 1 of 4 groups: Control (N), N + Prop, CIH and CIH + Prop. The CIH paradigm consisted of 8 cycles h-1, 8 h day-1, for 3 weeks. Propranolol was administered via drinking water to achieve a dose of 40 mg kg-1 day-1. Immunohistochemistry revealed the presence of both β1 and β2-adrenoceptor subtypes on the CB type I cell. CIH caused a 2-3-fold elevation in basal CB single-fibre chemoafferent activity and this was prevented by chronic propranolol treatment. Chemoafferent responses to hypoxia and mitochondrial inhibitors were attenuated by propranolol, an effect that was greater in CIH animals. Propranolol decreased respiratory frequency in normoxia and hypoxia in N and CIH. Propranolol also abolished the CIH mediated increase in vascular sympathetic nerve density. Arterial blood pressure was reduced in propranolol groups during hypoxia. Propranolol exaggerated the fall in blood pressure in most (6/7) CIH animals during hypoxia, suggestive of reduced sympathetic tone. These findings therefore identify new roles for β-adrenergic stimulation in evoking CB hyperactivity, sympathetic vascular hyperinnervation and altered blood pressure control in response to CIH.
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Affiliation(s)
- Abdulaziz A Alzahrani
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Respiratory Care Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Lily L Cao
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Hayyaf S Aldossary
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- College of Medicine, Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Demitris Nathanael
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Jiarong Fu
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Clare J Ray
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Keith L Brain
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Prem Kumar
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrew M Coney
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Andrew P Holmes
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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