小鼠舌菌状乳头及味蕾发育过程中组织形态变化及Shh的表达

摘要

背景:哺乳动物的舌背黏膜表面与味觉相关的主要是菌状乳头和轮廓乳头.味觉异常严重影响人们的生活质量,因此了解菌状乳头及其味蕾的发育过程,对于解决因其异常导致的味觉减退有重要意义.目的:观察小鼠舌菌状乳头及味蕾的发生、发育的组织形态变化.方法:取C57BL/6J小鼠胚胎期13.5-18.5 d(E13.5-E18.5),出生后0.5 d(PN0.5),PN4.5,PN7.5,PN14.5,PN21.5,PN90.5及出生后1.5年(PN1.5Y)的舌标本,进行扫描电镜观察及苏木精-伊红染色观察,同时使用Shh抗体进行免疫组织化学染色.取E16.5和E18.5小鼠舌标本进行S-100的免疫组织化学染色.结果与结论:①菌状乳头数量的决定主要发生于E13.5-E14.5.从E15.5开始,菌状乳头形态上逐渐发育成熟.味蕾发育开始于E16.5,至PN7.5味孔开始形成.成年期和老年期味蕾细胞和细胞间质减少,并可见到发生于菌状乳头周围的角化;②Shh在E14.5表达于菌状乳头的上皮细胞,E16.5-E18.5表达于菌状乳头顶端的上皮细胞,并且在成年期和老年期的味蕾细胞都有所表达.说明Shh在菌状乳头和味蕾发生、发育、成熟及维持的过程中发挥着重要作用;③在E18.5,S-100表达于菌状乳头下方的结缔组织,说明神经长入参与了味蕾发育完善成熟的过程.%BACKGROUND:Fungiform and circumvallate papillas on the surface of the mammal tongue mucosa are mainly associated with taste.Taste abnormalities seriously affect patients' quality of life,so it is of significance to understand the developmental processes of fungiform papilla and taste buds,for hypogeusia treatment.OBJECTIVE:To observe the morphological changes of mouse tongue fungiform papilla and taste buds during their developmental processes.METHODS:The tongues of C57BL/6J mice were observed by scanning electron microscope and hematoxylin eosin staining at embryonic days 13.5-18.5 (E13.5-E 18.5),postnatal (PN) days 0.5,4.5,7.5,14.5,21.5,90.5,and postnatal 1.5 years (PN1.5Y),and Shh antibody was used for immunohistochemical staining.Immunohistochemical staining of S-100 was performed on the tongue specimens of the mice at E16.5 and E18.5.RESULTS AND CONCLUSION:The number of fungiform papilla was mainly determined at E13.5-E14.5.From E15.5,the papilla gradually matured in morphology.Taste bud development began at E16.5,and the taste pore began to form at PN7.5.In adult and old age,taste bud cells and intercellular substances were reduced,and keratosis surrounding the fungiform papillae was visible.Shh was expressed in the epithelial cells of fungiform papilla at E14.5,in the epithelial cells at the tip of the fungiform papilla at E16.5 and E18.5,and in adult and elderly taste bud cells.These results suggest that Shh plays an important role in the development,maturation and maintenance of fungiform papillae and taste buds.S-100 is expressed in the connective tissue beneath the fungiform papillae at E18.5,indicating that the nerve extension may be involved in the development and maturation of taste buds.