目的:本研究研究了基因Fam20a敲除对小鼠唾液腺的影响,为涎腺功能障碍提供了一个潜在的基因治疗靶点。
方法:用Cre-Loxp构建具有基因型Fam20af/f的对照组和条件敲除(cKO)组的Fam20af/f;K14-Cre。从形态学方面研究了Fam20a对唾液腺的影响,功能和分子机制。
结果:在形态学方面,cKO小鼠的导管横截面面积与总数之比降低,而细胞外基质占总数的比例增加。在亚微观层面,Fam20a的敲除导致导管细胞的亚显微结构异常。功能上,cKO小鼠的唾液流速显著降低。结果与腺泡细胞标志物水通道蛋白5在腺泡细胞胞浆中异常弥漫性表达的变化一致。同时,导管细胞标志物细胞角蛋白7和神经生长因子β的表达显著降低,提示导管细胞的发育和功能异常。机制研究表明,Fam20a的缺失导致骨形态发生蛋白4(BMP4)的表达减少,磷酸化细胞外信号调节蛋白1/2(ERK1/2)占总ERK1/2的比例显着降低。这些变化表明Fam20a的丢失减弱了BMP/ERK信号通路的活性。
结论:Fam20a影响唾液腺的形态和功能,可能通过减弱BMP/ERK信号通路的活性。
OBJECTIVE: The influence of the knockout of gene
Fam20a on mice salivary glands was studied in this research, to provide a potential gene therapeutic target for salivary gland dysfunction.
METHODS: The control group with genotype Fam20af/f and conditional knockout (cKO) group with Fam20af/f;K14-Cre were constructed with Cre-Loxp. The influence of
Fam20a on the salivary glands was studied in terms of morphology, functionality and molecular mechanism.
RESULTS: In terms of morphology, the cross-sectional area ratio of ductal to the total was reduced in the cKO mice, while that of extracellular matrix to the total was increased. At the sub-microscopic level, the knockout of
Fam20a led to abnormal sub-microscopic structure of the duct cells. Functionally, saliva flow rate was significantly reduced in cKO mice. The result was consistent with the change of acinar cell marker Aquaporin 5 which was abnormally diffusely expressed in the cytoplasm of acinar cells. Meanwhile, the expression of ductal cell markers Cytokeratin 7 and nerve growth factor β were significantly decreased, suggesting the abnormal development and function of the duct cells. The research on the mechanism reveals that the loss of
Fam20a led to the decreased expression and varied localization of bone morphogenetic protein 4 (BMP4), and a significant decrease of the proportion of phosphorylated extracellular signal-regulated protein1/2 (ERK1/2) to total ERK1/2. These changes suggested that the loss of
Fam20a attenuated the activity of the BMP/ERK signaling pathway.
CONCLUSIONS: Fam20a affects the morphology and function of salivary glands, probably by attenuating the activity of the BMP/ERK signaling pathway.