This proposal examines the importance and mechanisms of action of S-nitrosothiols (SNOs) in the carotid body regulation of ventilation. We have focused on our recent novel findings that (1) preformed vesicular pools of SNOs in the carotid bodies may be involved in mediating the ventilatory responses to hypoxia, hypercapnia, and acidosis, and (2) systemic injections of SNOs such as S-nitroso-L-cysteine (SNO-L-CYS) elicit Increases in minute ventilation that are markedly reduced in conscious rats with bilateral carotid sinus nerve transection (i.e., rats in which the connections between the carotid bodies and brainstem have been severed) and by putative SNO-L-CYS """"""""recognition site"""""""" antagonists. The CONCEPTS driving this proposal are that (1) exocytotic release of vesicular pools of excitatory SNOs such as SNO-L-CYS from primary glomus cells (PGCs) of carotid bodies mediate the ventilatory responses to hypoxia/hypercapnia/acidosis, (2) these vesicles are mobilized by Ca^*-dependent and Ca^*-independent mechanisms involving an array oif fusion proteins, and (3) PGC-derived SNOs exert their effects via activation of specific SNO recognition sites on chemoafferent nerve terminals.
AIM 1 : To determine (1) the localization of endothelial nitric oxide synthase (eNOS) and the fusion proteins serving vesicular exocytosis in PGCs, (2) whether SNOs exist in cytoplasmic vesicles of PGCs, and (3) subcellular localization of high-affinity binding sites (putative SNO recognition sites) and low-affinity binding sites (putative S-nitrosylation sites) for SNO-L-CYS in the carotid bodies.
AIM 2 : To characterize the importance of carotid body SNOs in the regulation of ventilatory control and the ventilatory responses to hypoxia/hypercapnia/acidosis, in rats and in transgenic and normal mice. This project will provide insights into (1) the role of carotid body SNOs in ventilatory control of rats and mice, (2) mechanisms regulating the synthesis/storage of SNOs in PGCs in the carotid bodies, (3) the mechanisms regulating the exocytosis of SNOs during hypoxia, hypercapnia and acidosis, and (4) the signaling elements mediating the SNO responses. The knowledge derived from this project will drive future studies directed at testing the hypothesis that free radical-induced damage to SNO release mechanisms and SNO-recognition sites in the carotid bodies participate in the etiology of ventilatory disease states.

Public Health Relevance

The on-going work of our collaborative team is providing compelling evidence that S-nitrosothiols will prove to be major regulators of breathing in mammals via their presence and bioactivity within the carotid bodies which are major neural structures controlling breathing. Accordingly, disturbances in synthesis, disposition and biological activities of these endogenous compounds may have profound effects on breathing and may contribute to breathing disorders associated with disease states such as diabetes and sleep apnea.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Program Projects (P01)
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Heart, Lung, and Blood Initial Review Group (HLBP)
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University of Virginia
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Zaman, Khalequz; Sawczak, Victoria; Zaidi, Atiya et al. (2016) Augmentation of CFTR maturation by S-nitrosoglutathione reductase. Am J Physiol Lung Cell Mol Physiol 310:L263-70
Raffay, Thomas M; Dylag, Andrew M; Di Fiore, Juliann M et al. (2016) S-Nitrosoglutathione Attenuates Airway Hyperresponsiveness in Murine Bronchopulmonary Dysplasia. Mol Pharmacol 90:418-26
Wallrabe, Horst; Sun, Yuansheng; Fang, Xiaolan et al. (2015) Three-color confocal Förster (or fluorescence) resonance energy transfer microscopy: Quantitative analysis of protein interactions in the nucleation of actin filaments in live cells. Cytometry A 87:580-8
Sawczak, Victoria; Getsy, Paulina; Zaidi, Aliya et al. (2015) Novel Approaches for Potential Therapy of Cystic Fibrosis. Curr Drug Targets 16:923-36
Marozkina, Nadzeya V; Wang, Xin-Qun; Stsiapura, Vitali et al. (2015) Phenotype of asthmatics with increased airway S-nitrosoglutathione reductase activity. Eur Respir J 45:87-97
Palmer, Lisa A; Kimberly deRonde; Brown-Steinke, Kathleen et al. (2015) Hypoxia-induced changes in protein s-nitrosylation in female mouse brainstem. Am J Respir Cell Mol Biol 52:37-45
Marozkina, Nadzeya V; Gaston, Benjamin (2015) Nitrogen chemistry and lung physiology. Annu Rev Physiol 77:431-52
Sun, Yuansheng; Periasamy, Ammasi (2015) Localizing protein-protein interactions in living cells using fluorescence lifetime imaging microscopy. Methods Mol Biol 1251:83-107
Chelko, Stephen P; Schmiedt, Chad W; Lewis, Tristan H et al. (2014) Occipital Artery Function during the Development of 2-Kidney, 1-Clip Hypertension in Rats. Int J Vasc Med 2014:659617
Getsy, Paulina M; Davis, Jesse; Coffee, Gregory A et al. (2014) Enhanced non-eupneic breathing following hypoxic, hypercapnic or hypoxic-hypercapnic gas challenges in conscious mice. Respir Physiol Neurobiol 204:147-59

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