In airway smooth muscle (ASM) cells, sarcoplasmic reticulum (SR) Ca2+ release via ryanodine receptor channels during acetylcholine (Ach) stimulation is mediated by cyclic ADP-ribose (cADPR), a metabolite of beta-NAD+. The enzymes for the synthesis and degradation of cADPR through ADP-ribosyl cyclase and cADPR hydrolase respectively are associated with a single bifunctional protein, CD38. In ASM, RT-PCR and Western blot analyses reveal CD38 expression. In ASM, Ach causes CD38 activation, reflected as increased ADP-ribosyl cyclase activity and cADPR production. Pre-incubation of ASM with 8-Br-cADPR, a cADPR antagonist results in attenuated Ca2+ responses and contraction to agonists. Agonists elicit decreased Ca2+ responses in ASM cells transfected with anti-sense CD38 and cells from CD38 knockout mice. These studies demonstrate the role of CD38/cADPR signaling in ASM Ca2+ regulation. cADPR-mediated SR Ca2+ release in porcine ASM cells is agonist specific. 8-Br-cADPR inhibits Ach- and ET-1-, but not histamine-, induced Ca2+ release. CD38/cADPR signaling is coupled to M2 muscarinic receptors, suggesting receptor subtype specific activation. Heightened [Ca2+]i response to agonists is a feature of airway inflammatory diseases. The pathogenesis involves alterations in gene expression and activation of second messengers involved in Ca2+ regulation. Inflammatory cytokines, IL-1beta, TNF-alpha and IFN-gamma up regulate CD38 expression and ADP-ribosyl cyclase activity in human ASM cells, where the [Ca2+]i responses to BK, Ach, histamine and thrombin are augmented and 8-Br-cADPR attenuates this response. In anti-sense CD38 transfected cells exposed to TNF-alpha, the [Ca2+]i responses to BK are lower than in controls. These findings have provided new insights into the role of CD38-cADPR-SR Ca2+ release in ASM hyperresponsiveness. The goal of the proposed studies is to obtain evidence for CD38 activation by multiple contractile agonists and its role in altered [Ca2+]i regulation and contractility of ASM in inflammatory diseases such as asthma. The overall hypothesis of the proposed study is that contractile agonists activate CD38/cADPR signaling in ASM cells to elevate [Ca2+]i, and cytokines upregulate CD38 expression, cADPR mediated calcium mobilization and contraction contributing to airway hyperresponsiveness. Our findings will lead to the development of potential drugs that target this signaling pathway.
Guedes, Alonso G P; Jude, Joseph A; Paulin, Jaime et al. (2015) Airway responsiveness in CD38-deficient mice in allergic airway disease: studies with bone marrow chimeras. Am J Physiol Lung Cell Mol Physiol 308:L485-93 |
Dileepan, Mythili; Jude, Joseph A; Rao, Savita P et al. (2014) MicroRNA-708 regulates CD38 expression through signaling pathways JNK MAP kinase and PTEN/AKT in human airway smooth muscle cells. Respir Res 15:107 |
Jude, Joseph A; Tirumurugaan, Krishnaswamy G; Kang, Bit Na et al. (2012) Regulation of CD38 expression in human airway smooth muscle cells: role of class I phosphatidylinositol 3 kinases. Am J Respir Cell Mol Biol 47:427-35 |
Jude, Joseph A; Dileepan, Mythili; Subramanian, Subbaya et al. (2012) miR-140-3p regulation of TNF-?-induced CD38 expression in human airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 303:L460-8 |
Jude, Joseph A; Panettieri Jr, Reynold A; Walseth, Timothy F et al. (2011) TNF-? regulation of CD38 expression in human airway smooth muscle: role of MAP kinases and NF-?B. Adv Exp Med Biol 691:449-59 |
Jude, Joseph A; Solway, Julian; Panettieri Jr, Reynold A et al. (2010) Differential induction of CD38 expression by TNF-{alpha} in asthmatic airway smooth muscle cells. Am J Physiol Lung Cell Mol Physiol 299:L879-90 |
Kang, Bit Na; Jude, Joseph A; Panettieri Jr, Reynold A et al. (2008) Glucocorticoid regulation of CD38 expression in human airway smooth muscle cells: role of dual specificity phosphatase 1. Am J Physiol Lung Cell Mol Physiol 295:L186-93 |
Guedes, Alonso G P; Jude, Joseph A; Paulin, Jaime et al. (2008) Role of CD38 in TNF-alpha-induced airway hyperresponsiveness. Am J Physiol Lung Cell Mol Physiol 294:L290-9 |
Tirumurugaan, Krishnaswamy G; Kang, Bit Na; Panettieri, Reynold A et al. (2008) Regulation of the cd38 promoter in human airway smooth muscle cells by TNF-alpha and dexamethasone. Respir Res 9:26 |
Jude, Joseph A; Wylam, Mark E; Walseth, Timothy F et al. (2008) Calcium signaling in airway smooth muscle. Proc Am Thorac Soc 5:15-22 |
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