Adhikari Nirpesh, Neupane Sanjiv, Roh Jiyeon, Aryal Yam Prasad, Lee Eui-Seon, Jung Jae-Kwang, Yamamoto Hitoshi, Lee Youngkyun, Sohn Wern-Joo, Kim Jae-Young, Kim Ji-Youn
Department of Biochemistry, School of Dentistry, IHBR, Kyungpook National University, Daegu, South Korea.
Department of Dental Hygiene, Wonju College of Medicine, Yonsei University, Wonju, South Korea.
Genes Genomics. 2018 Jun 22. doi: 10.1007/s13258-018-0715-z.
Salivary gland (SG) development involves dynamic epithelial-mesenchymal interactions resulting in the formation of highly branched epithelial structures that produce and secrete saliva. The SG epithelium differentiates into saliva-producing terminal buds, i.e., acini, and transporting ducts. Most studies on the salivary gland have focused on branching morphogenesis; however, acinar cell differentiation underlying the determination of serous or mucous salivary glands is unclear. The objective of this study was to identify the mesenchymal signaling molecules involved in the epithelial differentiation of the salivary gland type as serous or mucous. Salivary glands undergoing stage-specific development, including the parotid gland (PG) and the sublingual gland (SLG) at embryonic day 14.5 (E14.5) were dissected. The glands were treated with dispase II to separate the epithelium and the mesenchyme. RNA from mesenchyme was processed for microarray analysis. Thereafter, microarray data were analyzed to identify putative candidate molecules involved in salivary gland differentiation and confirmed via quantitative reverse transcription polymerase chain reaction. The microarray analysis revealed the expression of 31,873 genes in the PG and SLG mesenchyme. Of the expressed genes 21,026 genes were found to be equally expressed (Fold change 1.000) in both PG and SLG mesenchyme. The numbers of genes expressed over onefold in the PG and SLG mesenchyme were found to be 5247 and 5600 respectively. On limiting the fold-change cut off value over 1.5 folds, only 214 and 137 genes were expressed over 1.5 folds in the PG and the SLG mesenchyme respectively. Our findings suggest that differential expression patterns of the mesenchymal signaling molecules are involved in fate determination of the salivary acinar cell types during mouse embryogenesis. In the near future, functional evaluation of the candidate genes will be performed using gain- and loss-of-function mutation studies during in vitro organ cultivation.
唾液腺（SG）的发育涉及动态的上皮-间充质相互作用，从而形成产生和分泌唾液的高度分支的上皮结构。唾液腺上皮分化为产生唾液的终末芽，即腺泡，以及输送导管。大多数关于唾液腺的研究都集中在分支形态发生上；然而，浆液性或黏液性腺泡细胞分化背后的机制尚不清楚。本研究的目的是确定参与唾液腺上皮分化为浆液性或黏液性类型的间充质信号分子。解剖处于特定发育阶段的唾液腺，包括胚胎第14.5天（E14.5）的腮腺（PG）和舌下腺（SLG）。用Dispase II处理腺体以分离上皮和间充质。对间充质的RNA进行微阵列分析。此后，分析微阵列数据以鉴定参与唾液腺分化的假定候选分子，并通过定量逆转录聚合酶链反应进行确认。微阵列分析揭示了PG和SLG间充质中31,873个基因的表达。在表达的基因中，发现21,026个基因在PG和SLG间充质中表达水平相同（倍数变化为1.000）。在PG和SLG间充质中表达超过一倍的基因数量分别为5247和5600。当将倍数变化截止值限制在1.5倍以上时，在PG和SLG间充质中分别只有214和137个基因表达超过1.5倍。我们的研究结果表明，间充质信号分子的差异表达模式参与了小鼠胚胎发育过程中唾液腺泡细胞类型的命运决定。在不久的将来，将在体外器官培养过程中使用功能获得和功能丧失突变研究对候选基因进行功能评估。
