Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus
Ultrastructural and biochemical characterization of mechanically adaptable collagenous structures in the edible sea urchin Paracentrotus lividus
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DOI：
10.1016/j.zool.2014.10.003
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发表时间：
2015-06-01
期刊：
影响因子：
2
通讯作者：
Carnevali, M. Daniela Candia
中科院分区：
文献类型：
--
作者：
Barbaglio, Alice;Tricarico, Serena;Carnevali, M. Daniela Candia
脊椎动物结缔组织的粘弹性在生理时间尺度内很少发生显著变化，唯一的主要例外是哺乳动物子宫颈在妊娠结束时的可逆性去硬化。与此相反，棘皮动物（海胆、海星、海参等）的结缔组织可以在大约一秒到几分钟的时间尺度内在刚性和柔性条件之间可逆地切换。阐明这种突变的分子机制对动物学、生态学和进化领域都有重要意义。兽医学和生物医学科学也可能产生重要的信息，特别是关于结缔组织结构的病理性塑化或硬化。在本研究中，我们分析了两个代表性的模型，罗盘降韧带和口缘膜的食用海胆Paracentrotus lividus，在三个不同的机械状态下进行比较方面的超微结构和生化。结果提供了进一步的证据，棘皮动物结缔组织的机械适应性并不一定意味着胶原纤维本身的变化。较高的糖胺聚糖（GAG）的内容注册在口缘膜相对于罗盘降压韧带表明这些分子在两个可变的胶原组织中的不同作用。GAG可能参与突变现象需要进一步澄清。在从顺应性条件转变为标准条件的过程中，仅在罗盘降韧带中检测到GAG含量的显著变化。在超微结构（胶原纤维组装）和生物化学（两个α链）方面的相似性，发现这两种模型和哺乳动物胶原蛋白。然而，胶原蛋白免疫反应性，α链迁移SDS-PAGE和BLAST比对的差异突出了海胆胶原蛋白相对于哺乳动物胶原蛋白的独特性。(C)2015 Elsevier GmbH. All rights reserved.
The viscoelastic properties of vertebrate connective tissues rarely undergo significant changes within physiological timescales, the only major exception being the reversible destiffening of the mammalian uterine cervix at the end of pregnancy. In contrast to this, the connective tissues of echinoderms (sea urchins, starfish, sea cucumbers, etc.) can switch reversibly between stiff and compliant conditions in timescales of around a second to minutes. Elucidation of the molecular mechanism underlying such mutability has implications for the zoological, ecological and evolutionary field. Important information could also arise for veterinary and biomedical sciences, particularly regarding the pathological plasticization or stiffening of connective tissue structures. In the present investigation we analyzed aspects of the ultrastructure and biochemistry in two representative models, the compass depressor ligament and the peristomial membrane of the edible sea urchin Paracentrotus lividus, compared in three different mechanical states. The results provide further evidence that the mechanical adaptability of echinoderm connective tissues does not necessarily imply changes in the collagen fibrils themselves. The higher glycosaminoglycan (GAG) content registered in the peristomial membrane with respect to the compass depressor ligament suggests a diverse role of these molecules in the two mutable collagenous tissues. The possible involvement of GAG in the mutability phenomenon will need further clarification. During the shift from a compliant to a standard condition, significant changes in GAG content were detected only in the compass depressor ligament. Similarities in terms of ultrastructure (collagen fibrillar assembling) and biochemistry (two alpha chains) were found between the two models and mammalian collagen. Nevertheless, differences in collagen immunoreactivity, alpha chain migration on SDS-PAGE and BLAST alignment highlighted the uniqueness of sea urchin collagen with respect to mammalian collagen. (C) 2015 Elsevier GmbH. All rights reserved.