Shaalan A, Carpenter G, Proctor G. Inducible nitric oxide synthase-mediated injury in a mouse model of acute salivary gland dysfunction.
Nitric Oxide 2018;
78:95-102. [PMID:
29885902 DOI:
10.1016/j.niox.2018.06.001]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 05/31/2018] [Accepted: 06/04/2018] [Indexed: 01/27/2023]
Abstract
AIM
Inducible nitric oxide synthase (iNOS) is a key regulator of the innate immune system. The aim of the current study was to explore whether innate immune-mediated iNOS and reactive nitrogen species acutely perturb acinar cell physiology and calcium homeostasis of exocrine salivary tissues.
METHODS
Innate immunity in the submandibular gland of C57BL/6 mice was locally activated via intraductal retrograde infusion of polyinosinic:polycytidylic acid (poly (I:C). Expressions of iNOS and the activity of the reactive nitrogen species peroxynitrite, were evaluated by immunohistochemistry. Mice were pre-treated with the selective iNOS inhibitor aminoguanidine in order to substantiate the injurious effect of the nitrosative signal on the key calcium regulator sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2b) and calcium signalling.
RESULTS
Challenging salivary gland innate immunity with poly (I:C) prompted upregulated expression of iNOS and the generation of peroxynitrite. Inhibition of iNOS/peroxynitrite revealed the role played by upregulated nitrosative signalling in: dysregulated expression of SERCA2b, perturbed calcium homeostasis and loss of saliva secretion.
CONCLUSION
iNOS mediates disruption of exocrine calcium signalling causing secretory dysfunction following activation of innate immunity in a novel salivary gland injury model.
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