Central Laboratory, and Department of Oral and Maxillofacial Surgery School and Hospital of Stomatology, Peking University, Beijing, 100081, People's Republic of China.
Institute of Molecular Medicine, Peking University, Beijing, 100871, People's Republic of China.
Stem Cell Res Ther. 2022 Jul 28;13(1):368. doi: 10.1186/s13287-022-03033-5.
Salivary glands produce saliva that play essential roles in digestion and oral health. Derivation of salivary gland organoids from pluripotent stem cells (PSCs) provides a powerful platform to model the organogenesis processes during development. A few studies attempted to differentiate PSCs into salivary gland organoids. However, none of them could recapitulate the morphogenesis of the embryonic salivary glands, and most of the protocols involved complicated manufacturing processes.
To generate PSC-derived salivary gland placodes, the mouse embryonic stem cells were first differentiated into oral ectoderm by treatment with BMP4 on day 3. Retinoic acid and bFGF were then applied to the cultures from day 4 to day 6, followed by a 4-day treatment of FGF10. The PSC-derived salivary gland placodes on day 10 were transplanted to kidney capsules to determine the regenerative potential. Quantitative reverse transcriptase-polymerase chain reaction, immunofluorescence, and RNA-sequencing were performed to identify the PSC-derived SG placodes.
We showed that step-wise treatment of retinoic acid and FGF10 promoted the differentiation of PSCs into salivary gland placodes, which can recapitulate the early morphogenetic events of their fetal counterparts, including the thickening, invagination, and then formed initial buds. The PSC-derived salivary gland placodes also differentiated into developing duct structures and could develop to striated and excretory ducts when transplanted in vivo.
The present study provided an easy and safe method to generate salivary gland placodes from PSCs, which offered possibilities for studying salivary gland development in vitro and developing new cell therapies.
唾液腺分泌的唾液在消化和口腔健康中起着至关重要的作用。多能干细胞（PSCs）衍生的唾液腺类器官为模型发育过程中的器官发生过程提供了强大的平台。一些研究试图将 PSCs 分化为唾液腺类器官。然而，它们都不能再现胚胎唾液腺的形态发生，而且大多数方案都涉及复杂的制造过程。
为了生成 PSC 衍生的唾液腺基板，首先用 BMP4 在第 3 天处理将小鼠胚胎干细胞分化为口腔外胚层。然后从第 4 天到第 6 天用维甲酸和 bFGF 处理培养物，接着用 FGF10 处理 4 天。第 10 天的 PSC 衍生唾液腺基板被移植到肾囊中以确定再生潜力。进行定量逆转录聚合酶链反应、免疫荧光和 RNA 测序以鉴定 PSC 衍生的 SG 基板。
我们表明，逐步处理维甲酸和 FGF10 促进了 PSCs 分化为唾液腺基板，这可以再现其胎儿对应物的早期形态发生事件，包括增厚、内陷，然后形成初始芽。PSC 衍生的唾液腺基板也分化为发育中的导管结构，当体内移植时可以发育成纹状和排泄导管。
本研究提供了一种从 PSCs 生成唾液腺基板的简单、安全的方法，为体外研究唾液腺发育和开发新的细胞治疗方法提供了可能性。
