Terminally Differentiated Epithelial Cells of the Thymic Medulla and Skin Express Nicotinic Acetylcholine Receptor Subunit α3. (2nd July 2014)

• Record Type: Journal Article
• Authors: Soultanova, Aichurek; Panneck, Alexandra R.; Rafiq, Amir; Kummer, Wolfgang
• Other Names: Kawashima Koichiro Academic Editor.
• Is Part Of: BioMed research international. Volume 2014(2014)
• Publication Date: 2014-07-02
• Subjects: Medicine -- Periodicals; Biology -- Periodicals; Biotechnology -- Periodicals; Life sciences -- Periodicals; 610.5
• DOI: 10.1155/2014/757502
• Languages: English
• ISSNs: 2314-6133

Abstract

Abstract : In the thymus, T cell maturation is influenced by cholinergic signaling, and the predominantly expressed receptor is the α 3-subunit of nicotinic acetylcholine receptors, encoded by the chrna3 gene. We here determined its cellular distribution utilizing an appropriate eGFP-expressing reporter mouse strain. Neither T cells (CD4, CD8) nor mesenchymal cells (desmin-positive) expressed eGFP. In the thymic medulla, eGFP-positive cells either were scattered or, more frequently, formed small clusters resembling Hassall's corpuscles. Immunolabeling revealed that these cells were indeed terminally differentiated epithelial cells expressing keratin 10 (K10) but neither typical cortical (K8, K18) nor medullary keratins (K5, K14). These labeling patterns reflected those in the epidermis of the skin, where overlap of K10 and eGFP expression was seen in the stratum granulosum, whereas underlying basal cells displayed K5-immunoreactivity. A substantial portion of thymic eGFP-positive cells was also immunoreactive to chromogranin A, a peptide previously reported in epidermal keratinocytes in the stratum granulosum. Its fragment catestatin has multiple biological activities, including suppression of proinflammatory cytokine release from macrophages and inhibition of α 3 β 4 nAChR. The present findings suggest that its thymic production and/or release are under cholinergic control involving nAChR containing the α 3-subunit.