Li L, Wang H, Hu L, Wu X, Zhao B, Fan Z, Zhang C, Wang J, Wang S
a Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction , Capital Medical University School of Stomatology , Beijing.
b Department of Stomatology , Affiliated Hospital of ChengDe Medical College , Chengde.
Biotech Histochem. 2018;93(7):505-511. doi: 10.1080/10520295.2018.1463453. Epub 2018 May 23.
Aging salivary glands are characterized by a reduced volume of acini, increased duct volume, decline in the rate of synthesis of proteins and their mRNA, and decreased saliva flow. Sialin is a versatile anion transporter that is highly expressed in salivary glands and may also participate in maintenance of salivary gland function. We investigated age-associated sialin expression in salivary glands. Submandibular glands of mice and human parotid gland were collected at different ages. Western blot and real-time reverse transcription-polymerase chain reaction were used to analyze the protein and mRNA expression levels of sialin, respectively. Immunohistochemical and immunofluorescence staining were used to evaluate the histological pattern of sialin expression. We found that the protein and mRNA expression levels of sialin decreased with aging. The expression of sialin in the striated and excretory ducts of both mouse and human glands were reduced with age. In the mouse glands, the basal 2/3 of the cytoplasm was stained, while in the human glands the stain extended to the luminal surface. Sialin was expressed in the basal cytoplasmic membrane of acini and in some myoepithelial-like cells in young salivary glands, but had nearly disappeared in the aged salivary glands. Changes in sialin expression may be associated with changes in physiological function of salivary glands with aging.
衰老的唾液腺具有腺泡体积减小、导管体积增大、蛋白质及其信使核糖核酸合成速率下降以及唾液分泌减少的特征。唾液蛋白是一种多功能阴离子转运蛋白，在唾液腺中高度表达，也可能参与唾液腺功能的维持。我们研究了唾液腺中与年龄相关的唾液蛋白表达情况。在不同年龄段收集小鼠下颌下腺和人类腮腺。分别采用蛋白质免疫印迹法和实时逆转录聚合酶链反应分析唾液蛋白的蛋白质和信使核糖核酸表达水平。采用免疫组织化学和免疫荧光染色评估唾液蛋白表达的组织学模式。我们发现唾液蛋白的蛋白质和信使核糖核酸表达水平随衰老而降低。小鼠和人类唾液腺的纹状管和排泄管中唾液蛋白的表达均随年龄增长而减少。在小鼠唾液腺中，细胞质的基底2/3被染色，而在人类唾液腺中，染色延伸至管腔表面。唾液蛋白在年轻唾液腺的腺泡基底细胞膜和一些肌上皮样细胞中表达，但在衰老唾液腺中几乎消失。唾液蛋白表达的变化可能与衰老过程中唾液腺生理功能的变化有关。
