Santos-Ruiz Leonor, Santamaría Jesús Alberto, Becerra José
Department of Cell Biology, Genetics and Physiology, Faculty of Sciences, University of Málaga, Málaga, Spain.
Differentiation. 2005 Apr;73(4):175-87. doi: 10.1111/j.1432-0436.2005.00016.x.
Teleost fishes can regenerate their fins by epimorphic regeneration, a process that involves the transition of the formerly quiescent tissues of the stump to an active, growing state. This involves dynamic modifications of cell phenotype and behavior that must rely on alterations of the cytoskeleton. We have studied the spatial and temporal distribution of three main components of the cytoskeleton (actin, keratin and vimentin) in the regenerating fin, in order to establish putative relationships between cell cytoskeleton and cell behavior. According to our results, the massive rearrangement undergone by the epidermis right after injury, which takes place by cell migration, correlates with a transient down-regulation of keratin and a strong up-regulation of actin in the epidermal cells. During the subsequent epidermal growth, based on cell proliferation, keratin normal pattern is recovered while actin is down-regulated, although not to normal (quiescent) levels. The epidermal basal layer in contact with the blastema displays a particular cytoskeletal profile, different to that of the rest of the epidermal cells, which reflects its special features. In the connective tissue compartment, somatic cells do not contain vimentin, but keratin, as intermediate filament. Proliferative and migrative activation of these cells after injury correlates with actin up-regulation. Although this initial activation does not involve keratin down-regulation, blastemal cells were later observed to lack keratin, suggesting that such cytoskeletal modification might be needed for connective tissue cells to dedifferentiate and form the blastema. Cell differentiation in the newly formed, regenerated ray is accompanied by actin down-regulation and keratin up-regulation.
硬骨鱼可以通过形态再生来再生它们的鳍，这一过程涉及残端先前静止的组织向活跃的生长状态转变。这涉及细胞表型和行为的动态改变，而这些改变必须依赖于细胞骨架的变化。我们研究了再生鳍中细胞骨架的三个主要成分（肌动蛋白、角蛋白和波形蛋白）的时空分布，以便确定细胞骨架与细胞行为之间的假定关系。根据我们的结果，损伤后表皮立即通过细胞迁移进行的大规模重排与角蛋白的短暂下调以及表皮细胞中肌动蛋白的强烈上调相关。在随后基于细胞增殖的表皮生长过程中，角蛋白恢复正常模式，而肌动蛋白下调，尽管未降至正常（静止）水平。与芽基接触的表皮基底层呈现出一种特殊的细胞骨架特征，与其他表皮细胞不同，这反映了其特殊性质。在结缔组织区室中，体细胞不含波形蛋白，而是含有角蛋白作为中间丝。损伤后这些细胞的增殖和迁移激活与肌动蛋白上调相关。虽然这种初始激活不涉及角蛋白下调，但后来观察到芽基细胞缺乏角蛋白，这表明这种细胞骨架修饰可能是结缔组织细胞去分化并形成芽基所必需的。新形成的再生鳍条中的细胞分化伴随着肌动蛋白下调和角蛋白上调。
