Long-term administration of whey alters atrophy, gene expression profiles and dysfunction of salivary glands in elderly rats

Abstract

Salivary glands in elderly individuals commonly exhibit morphological changes and dysfunction resulting in xerostomia. Long-term (4-week) drinking of whey prevented and/or restored age-dependent decline of salivary volume and protein concentration, and atrophy of sublingual glands (SLGs) significantly in 88-week-old rats. The transcripts of 42 genes were up-regulated and 7 genes were down-regulated by more than 1.5-fold change with FDR ≦ 0.1 after whey-drinking. The expression levels of genes associated with salivary proteins and tissue repair were significantly increased, while those associated with lipid metabolism were decreased. Venn diagram analysis revealed that expressions of 13 genes, including Tcfap2b and Abpa, were induced significantly by whey-drinking. Furthermore, secretory protein levels in SLGs and saliva were revealed by immunoblot analysis. This is the first study to report that whey-administration can prevent and/or restore age-dependent atrophy and functional decline of SLGs in relation to gene expression and thus may serve as a functional food ingredient.

Long-Term Oral Administration of LLHK, LHK, and HK Alters Gene Expression Profile and Restores Age-Dependent Atrophy and Dysfunction of Rat Salivary Glands

“…LHK treatment induced the expression of the Tcfap2β gene in salivary glands. As reported previously, whey consumption induces Tcfap2β expression [17]. The AP-2 family of transcription factors consists of five members, AP-2α, 2β, 2γ, 2δ, and 2ε, each encoded by a separate gene [34], and is known to have tissue-specific expression to regulate the expression of other genes [23].…”

“…We previously reported that the administration of whey from the milk of Jersey cattle mitigates age-dependent atrophy and functional decline of salivary glands accompanied with changes in gene expression [17]. The major components of whey proteins are of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and immunoglobulin, representing 50%, 20%, 10% and 10% of the whey fraction, respectively [18].…”

Effect of Jersey cow defatted dry milk on salivary volume and composition in elderly persons : a pilot study

“…Previously, we reported that the administration of whey from Jersey cow milk mitigates age-dependent atrophy and functional decline of salivary glands accompanied with changes in gene expression in rats (12). We found that the bioactive peptides, which were LLHK, LHK, and HK derived from β-lactoglobulin C variant, prevent and / or restore the age-depending decline in structure and function of salivary gland (15).…”

“…We previously reported that the administration of whey from Jersey cow milk mitigates the age-dependent atrophy and functional decline of rat salivary glands, accompanied with changes in gene expression (12). β-Lactoglobulin A and B are the most common variants, while the β-lactoglobulin C variant is observed in Jersey cattle.…”