Silencing of the hydra serine protease inhibitor Kazal1 gene mimics the human SPINK1 pancreatic phenotype
Silencing of the hydra serine protease inhibitor Kazal1 gene mimics the human SPINK1 pancreatic phenotype
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DOI：
10.1242/jcs.02807
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发表时间：
2006-03-01
影响因子：
4
通讯作者：
Galliot, B
中科院分区：
文献类型：
--
作者：
Chera, S;de Rosa, R;Galliot, B
在水螅中，内胚层上皮细胞与产生酶原并表达进化保守基因 Kazall 的腺细胞一起执行消化功能。为了评估水螅Kazall 的功能，我们通过双链RNA 喂养来沉默基因表达。渐进的 Kazall 沉默影响了体内平衡条件，低出芽率和诱导的动物死亡证明了这一点。与此同时，观察到腺体细胞发生剧烈的混乱，随后大量死亡，而消化细胞的细胞质变得高度空泡。这些液泡内线粒体和晚期内体的存在将它们指定为自噬体。在 Kazal1(-) 水螅中，再生尖端中增强的 Kazall 表达强烈减弱，截肢应激导致腺细胞立即解体、消化细胞形成空泡，并在长时间沉默后死亡。刺胞动物中基因敲低产生的第一个细胞表型表明，Kazal1 丝氨酸蛋白酶抑制剂活性是防止完整水螅中过度自噬并发挥细胞保护功能以在截肢应激中生存所必需的。有趣的是，这些功能与分别在人和小鼠的 SPINK1 和 SPINK3 基因的 Kazal 结构域内突变时观察到的胰腺自噬表型相似。
In hydra, the endodermal epithelial cells carry out the digestive function together with the gland cells that produce zymogens and express the evolutionarily conserved gene Kazall. To assess the hydra Kazall function, we silenced gene expression through double-stranded RNA feeding. A progressive Kazall silencing affected homeostatic conditions as evidenced by the low budding rate and the induced animal death. Concomitantly, a dramatic disorganization followed by a massive death of gland cells was observed, whereas the cytoplasm of digestive cells became highly vacuolated. The presence of mitochondria and late endosomes within those vacuoles assigned them as autophagosomes. The enhanced Kazall expression in regenerating tips was strongly diminished in Kazal1(-) hydra, and the amputation stress led to an immediate disorganization of the gland cells, vacuolization of the digestive cells and death after prolonged silencing. This first cellular phenotype resulting from a gene knockdown in cnidarians suggests that the Kazal1 serine-protease-inhibitor activity is required to prevent excessive autophagy in intact hydra and to exert a cytoprotective function to survive the amputation stress. Interestingly, these functions parallel the pancreatic autophagy phenotype observed upon mutation within the Kazal domain of the SPINK1 and SPINK3 genes in human and mice, respectively.