背景:每个内分泌汗腺(ESG)都是具有中央管腔的单管状结构,在最初的固体细胞团中形成中空管腔是一个关键的发育过程。迄今为止,没有关于天然ESG管腔形成机制的报道。
方法:为了研究Sprague-Dawley(SD)大鼠ESG的管腔形态发生和管腔形成机制,获得E20.5,P1-P5,P7,P9,P12,P21,P28和P56的SD大鼠后足垫。通过HE染色和免疫荧光染色的极性标记物检查了ESGs的管腔形态发生。通过末端脱氧核苷酸转移酶dUTP缺口末端标记(TUNEL)凋亡测定和自噬标记LC3B免疫荧光染色检测管腔形成的可能机制,并通过哇巴因干预实验进一步探索。
结果:在SD大鼠ESG中,在P1处形成了微腔,在P3处出现了具有顶-基底极性的小完整腔。根尖标记F-肌动蛋白的表达,基底标记层粘连蛋白,基底外侧标记物E-cadherin与SD大鼠ESGs的管腔形成时间一致。在大鼠ESG发育过程中,未检测到细胞凋亡和自噬。然而,Na+-K+-ATP酶(NKA)的抑制与哇巴因导致管腔大小减小,尽管管腔形成的时间和极性蛋白的表达都没有改变。
结论:上皮极性驱动的膜分离而不是空化调节SD大鼠ESG的管腔形成。NKA调节的流体积聚驱动管腔扩张。
BACKGROUND: Each eccrine sweat gland (ESG) is a single-tubular structure with a central lumen, and the formation of hollow lumen in the initial solid cell mass is a key developmental process. To date, there are no reports on the mechanism of native ESG lumen formation.
METHODS: To investigate the lumen morphogenesis and the lumen formation mechanisms of Sprague-Dawley (SD) rat ESGs, SD rat hind-footpads at E20.5, P1-P5, P7, P9, P12, P21, P28 and P56 were obtained. The lumen morphogenesis of ESGs was examined by HE staining and immunofluorescence staining for polarity markers. The possible mechanisms of lumen formation were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis assay and autophagy marker LC3B immunofluorescence staining, and further explored by ouabain intervention experiment.
RESULTS: In SD rat ESGs, the microlumen was formed at P1, and the small intact lumen with apical-basal polarity appeared at P3. The expression of apical marker F-actin, basal marker Laminin, basolateral marker E-cadherin was consistent with the timing of lumen formation of SD rat ESGs. During rat ESG development, apoptosis and autophagy were not detected. However, inhibition of Na+-K+-ATPase (NKA) with ouabain resulted in decreased lumen size, although neither the timing of lumen formation nor the expression of polarity proteins was altered.
CONCLUSIONS: Epithelial polarity-driven membrane separation but not cavitation regulates lumen formation of SD rat ESGs. NKA-regulated fluid accumulation drives lumen expansion.