Activation of muscarinic receptors in rat parotid acinar cells induces AQP5 trafficking to nuclei and apical plasma membrane

Dexamethasone attenuates methacholine‐mediated aquaporin 5 downregulation in human nasal epithelial cells via suppression of NF‐κB activation

“…The results obtained in this study provide a further molecular basis for cholinergic impact in the airways and that methacholine dose‐dependently downregulates CREB phosphorylation at Ser133, probably by attenuating cAMP or PKA activity via G Q proteins, which in turn inhibits expression of AQP5 and leads to disruption of epithelial integrity. According to earlier work and the present results, AQP5 is expressed in the cell membrane, cytoplasm, and nucleus, and its intracellular trafficking is regulated by kinases and certain hormones . Parvin et al demonstrated that AQP5 trafficked from the intracellular vesicles to the apical membrane in response to stimulation of muscarinic receptors or to an increased intracellular calcium level in human salivary gland cells .…”

“…AQP5 is also involved in the pathophysiology of pulmonary edema, Ménière's disease, and other processes that involve abnormal transport of water . In rat parotid acinar cells, parasympathomimetics activate muscarinic receptors and induce AQP5 trafficking to the apical plasma membrane . It remains unknown whether parasympathomimetics have a similar impact on AQP5 regulation in human airway epithelium.…”

Structural Determinants of Oligomerization of the Aquaporin-4 Channel

“…Trigger-induced relocalization of AQP-containing vesicles to the plasma membrane is a well established regulatory mechanism for AQPs; the best studied example of this is relocalization of AQP2 to the apical membrane of the collecting duct in the mammalian kidney in response to arginine vasopressin (also called anti-diuretic hormone). There is also evidence for similar mechanisms for other AQPs including AQP1 ( 7 ), AQP5 ( 8 ), and AQP7 ( 9 ). A naturally occurring AQP2 mutant (R187C) has also been reported that is unable to relocalize in response to arginine vasopressin or to form tetramers ( 10 ).…”

Aquaporins in Salivary Glands: From Basic Research to Clinical Applications

“…In acinar cells, AQP5 traffics from intracellular vesicles to plasma membrane in response to acetylcholine [ 26 , 49 , 63 , 64 ]. In rat parotid glands, AQP5 also participates to the osmoregulation of acinar secretory granules [ 65 ].…”