Abstract
Taste perception is one of the important senses in mammals. Taste dysfunction causes significant inconvenience in daily life, leading to subhealth and even life-threatening condition. Aging is a major cause to taste dysfunction, while the underlying feature related to gustatory aging is still not known. Using single-cell RNA Sequencing, differentially expressed genes between aged and young taste papillae are identified, including upregulated mt-Nd4l and Xist, as well as downregulated Hsp90ab1 and Tmem59. In the Tmem59-/- circumvallate papillae (CVP), taste mature cell generation is impaired by reduction in the numbers of PLCβ2+ and Car4+ cells, as well as decreases in expression levels of taste transduction genes. Tmem59-/- mice showed deficits in sensitivities to tastants. Through screening by GenAge and DisGeNET databases, aging-dependent genes and oral disease-associated genes are identified in taste papillae. In the CVP, aging promotes intercellular communication reciprocally between (cycling) basal cell and mature taste cell by upregulated Crlf1/Lifr and Adam15/Itga5 signaling. By transcriptional network analysis, ribosome proteins, Anxa1, Prdx5, and Hmgb1/2 are identified as transcriptional hubs in the aged taste papillae. Chronological aging-associated transcriptional changes throughout taste cell maturation are revealed. Aged taste papillae contain more Muc5b+ cells that are not localized in gustatory gland. Collectively, this study shows molecular and cellular features associated with taste papilla aging.