1. Role of Transient Receptor Potential Vanilloid 4 in Neutrophil Activation and Acute Lung Injury.
- Author
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Yin J, Michalick L, Tang C, Tabuchi A, Goldenberg N, Dan Q, Awwad K, Wang L, Erfinanda L, Nouailles G, Witzenrath M, Vogelzang A, Lv L, Lee WL, Zhang H, Rotstein O, Kapus A, Szaszi K, Fleming I, Liedtke WB, Kuppe H, and Kuebler WM
- Subjects
- Acute Lung Injury chemically induced, Acute Lung Injury genetics, Acute Lung Injury prevention & control, Animals, Bone Marrow Transplantation, Calcium Signaling, Capillary Permeability, Disease Models, Animal, Humans, Hydrochloric Acid, Lung blood supply, Lung drug effects, Male, Mice, Knockout, Morpholines pharmacology, Neutrophils drug effects, Pneumonia metabolism, Pulmonary Edema metabolism, Pyrroles pharmacology, TRPV Cation Channels antagonists & inhibitors, TRPV Cation Channels deficiency, TRPV Cation Channels genetics, Acute Lung Injury metabolism, Lung metabolism, Neutrophil Activation drug effects, Neutrophils metabolism, TRPV Cation Channels metabolism
- Abstract
The cation channel transient receptor potential vanilloid (TRPV) 4 is expressed in endothelial and immune cells; however, its role in acute lung injury (ALI) is unclear. The functional relevance of TRPV4 was assessed in vivo, in isolated murine lungs, and in isolated neutrophils. Genetic deficiency of TRPV4 attenuated the functional, histological, and inflammatory hallmarks of acid-induced ALI. Similar protection was obtained with prophylactic administration of the TRPV4 inhibitor, GSK2193874; however, therapeutic administration of the TRPV4 inhibitor, HC-067047, after ALI induction had no beneficial effect. In isolated lungs, platelet-activating factor (PAF) increased vascular permeability in lungs perfused with trpv4(+/+) more than with trpv4(-/-) blood, independent of lung genotype, suggesting a contribution of TRPV4 on blood cells to lung vascular barrier failure. In neutrophils, TRPV4 inhibition or deficiency attenuated the PAF-induced increase in intracellular calcium. PAF induced formation of epoxyeicosatrienoic acids by neutrophils, which, in turn, stimulated TRPV4-dependent Ca(2+) signaling, whereas inhibition of epoxyeicosatrienoic acid formation inhibited the Ca(2+) response to PAF. TRPV4 deficiency prevented neutrophil responses to proinflammatory stimuli, including the formation of reactive oxygen species, neutrophil adhesion, and chemotaxis, putatively due to reduced activation of Rac. In chimeric mice, however, the majority of protective effects in acid-induced ALI were attributable to genetic deficiency of TRPV4 in parenchymal tissue, whereas TRPV4 deficiency in circulating blood cells primarily reduced lung myeloperoxidase activity. Our findings identify TRPV4 as novel regulator of neutrophil activation and suggest contributions of both parenchymal and neutrophilic TRPV4 in the pathophysiology of ALI.
- Published
- 2016
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