Occurrence of heparin in the invertebrate Styela plicata (Tunicata) is restricted to cell layers facing the outside environment -: An ancient role in defense?
Occurrence of heparin in the invertebrate Styela plicata (Tunicata) is restricted to cell layers facing the outside environment -: An ancient role in defense?
复制标题
DOI：
10.1074/jbc.m005830200
复制
发表时间：
2000-11-17
影响因子：
4.8
通讯作者：
Pavao, MSG
中科院分区：
文献类型：
--
作者：
Cavalcante, MCM;Allodi, S;Pavao, MSG
肝素是脊椎动物肥大细胞的胞内产物，目前用作外源性抗凝剂。尽管外源性肝素具有很强的生物学活性，但其生理功能尚不清楚。在这里，肝素与类似的结构和抗凝血性能的哺乳动物对应物被证明是发生作为测试细胞的细胞内产物，细胞单层，包围卵的无脊椎动物皱瘤海鞘（Chordata被膜）。与哺乳动物肥大细胞的情况一样，在与化合物48/80孵育后，从细胞内颗粒中除去来自海鞘测试细胞的肝素。受精后，发育中的幼虫周围的测试细胞仍然保留肝素作为异染颗粒。在成年无脊椎动物中，肝素作为细胞内颗粒存在于肠和咽腔周围上皮细胞的顶端，与外部环境密切接触。这是第一次描述肝素存在于暴露于外部试剂的部位管腔周围的上皮样细胞的细胞质颗粒中。这种安排可能反映了肝素在这种无脊椎动物的防御机制的参与。
Heparin is an intracellular product of vertebrate mast cell currently used as exogenous anticoagulant. Despite of the potent biological activities of exogenous heparin, its physiological function has not been clearly established yet. Here, a heparin with similar structure and anticoagulant properties to the mammalian counterpart was shown to occur as the intracellular product of test cells, a cell monolayer that surrounds egg of the invertebrate Styela plicata (Chordata-Tunicata). As in the case of mammalian mast cells, heparin from the ascidian test cells is removed from the intracellular granules after incubation with compound 48/80, Following fertilization, the test cells surrounding the developing larva still retain heparin as metachromatic granulation. In the adult invertebrate, heparin occurs as intracellular granules at the apical tip of epithelial cells surrounding the lumen of both intestine and pharynx, in close contact with the external environment. This is the first description of the presence of heparin in cytoplasmic granules of epithelial-like cells around the lumen of sites exposed to external agents. This arrangement may reflect the participation of heparin in defense mechanisms in this invertebrate.