Single-cell analysis reveals the transcriptional alterations in the submandibular glands of aged mice.

Objectives: Aging-related salivary gland changes, such as lymphocyte infiltration and acinar cell loss decrease saliva secretion, thereby affecting quality of life. The precise molecular mechanisms underlying these changes remain unclear.
Methods: We here performed single-cell RNA sequencing to clarify gene expression changes in each cell type comprising the submandibular glands (SMGs) of adult and aged mice.
Results: The proportion of acinar cells decreased in various epithelial clusters annotated with cell type-specific marker genes. Expression levels of the cellular senescence markers, Cdkn2a/p16 and Cdkn1a/p21, were increased in the basal and striated ducts of aged SMGs relative to their levels in those of adult SMGs. In contrast, senescence-associated secretory phenotype-related genes, except transforming growth factor-β, exhibited little change in expression in aged SMGs relative to adult SMGs.
Conclusions: Gene Ontology analysis revealed increased expression levels of genes encoding major histocompatibility complex (MHC) class I components in the ductal component cells of aged SMGs. MHC class I expression may thus be associated with salivary gland aging.
Competing Interests: Declaration of competing interest These authors declared no competing interests in this study.
(Copyright © 2023. Published by Elsevier B.V.)