ORIGINAL RESEARCH article
Front. Dent. Med.
Sec. Systems Integration
Volume 6 - 2025 | doi: 10.3389/fdmed.2025.1585554
Expression Profiles of SGK-1 and α-ENaC in Minor Salivary Glands of Subjects with Xerostomia
Provisionally accepted
- Augusta University, Augusta, United States
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Epithelial sodium channel (ENaC) is a major conduit for sodium transport across the cell membrane and its activity is regulated by multiple factors/mechanisms including the serum and glucocorticoid-regulated kinase-1 (SGK-1). Saliva production and secretion are complex processes with ENaC regulation of ionic composition of saliva being an essential event prior to ultimate secretion of hypotonic saliva into the oral cavity. However, the status of salivary gland SGK-1, in the context of ENaC, remains to be determined. We tested the hypothesis that lower lip minor salivary gland expressions of SGK-1 and ENaC are affected in subjects reporting xerostomia. Accordingly, archived biopsy specimens of subjects with a diagnosis of mucocele (control; n=7) and those of subjects complaining of dry mouth (experimental; n=12) were subjected to histopathological and immunohistochemical assessments for SGK-1, its phosphorylated (active) form (pSGK-1) and the alpha subunit of ENaC (α-ENaC). Control specimens displayed extravasated mucus surrounded by a capsule of inflamed granulation tissue while experimental specimens showed patchy peri-ductal, predominantly lymphocytic, infiltrates. Control specimens showed variable degrees of SGK-1 and pSGK-1 immunolabeling of ductal epithelial cells. On the other hand, experimental specimens displayed patchy and strong SGK-1 but variable degrees of pSGK-1 immunolabeling of ductal epithelial cells. While control specimens showed variable ductal α-ENaC immunolabeling, those of the experimental group displayed primarily diffuse cytoplasmic, with some membrane, immunolabeling in ductal cells. Semi-quantitative analyses, using Image J Fiji, showed increased normalized staining for α-ENaC and SGK-1, but not pSGK-1, for experimental compared to control cases. Collectively, the data suggest a disjoint between the active form of the kinase and α-ENaC in minor salivary glands in xerostomia and that higher SGK-1 and α-ENaC may serve as diagnostic markers for this condition.
Keywords: Lower lip biopsy, Salivary Glands, Serum and Glucocorticoid-Regulated Kinase-1, Epithelial Sodium Channel, Xerostomia
Received: 06 Mar 2025; Accepted: 16 Jul 2025.
Copyright: © 2025 Mozaffari and Abdelsayed. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Mahmood S Mozaffari, Augusta University, Augusta, United States
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