Departamento de Biologia Molecular, Universidade Federal da Paraíba, Campus I, Cidade Universitária, CEP: 58051-900, João Pessoa, Paraíba, Brazil.
Biosci Rep. 2010 Mar 17;30(4):257-65. doi: 10.1042/BSR20090081.
ABC transporter (ATP-binding-cassette transporter) proteins have been strongly associated with the phenomenon of multidrug resistance in cancer cells. Furthermore, their physiological expression has been studied in many organisms, including bacteria, fungi, plants and vertebrate or invertebrate animals. Their widespread expression through the evolution demonstrates their relevance to the survival of living things. In the present study, we characterized the functional activity of ABCB1 and ABCC1 proteins in gametes and embryonic cells of the sea urchin Echinometra lucunter. The ABC transporter proteins' functional activity was up-regulated post-fertilization. Eggs and spermatozoa of E. lucunter accumulated more C-AM (calcein acetoxymethyl ester), a fluorescent substrate of ABCB1 and ABCC1 proteins, than embryonic cells. Verapamil, reversin 205 and indomethacin were able to increase C-AM influx in eggs and embryos. However, verapamil and reversin 205 were more efficient than indomethacin, suggesting a predominance of ABCB1 protein over ABCC1 protein activity. Multidrug resistance modulating agents, at the concentration range that inhibited ABC transporter proteins, did not block the embryonic development until blastula stage. However, inhibition of ABCB1-mediated efflux by reversin 205 circumvented resistance of embryos to the antimitotic vinca alkaloid vinblastine. Embryonic development was more efficiently blocked when colchicine was previously added to eggs than to embryos 5 min after fertilization. This set of results suggests that these proteins act as a fundamental biochemical barrier conferring a protective physiological role against toxic xenobiotics in E. lucunter embryos.
ABC 转运蛋白（ATP 结合盒转运蛋白）与癌细胞的多药耐药现象密切相关。此外，它们的生理表达已在许多生物体中进行了研究，包括细菌、真菌、植物以及脊椎动物或无脊椎动物。它们在进化过程中的广泛表达表明它们与生物的生存息息相关。在本研究中，我们对海胆 Echinometra lucunter 的配子和胚胎细胞中 ABCB1 和 ABCC1 蛋白的功能活性进行了表征。受精后 ABC 转运蛋白的功能活性上调。E. lucunter 的卵子和精子比胚胎细胞积累了更多的 C-AM（钙黄绿素乙酰氧甲酯），这是 ABCB1 和 ABCC1 蛋白的荧光底物。维拉帕米、reversin 205 和吲哚美辛能够增加卵子和胚胎中 C-AM 的内流。然而，维拉帕米和 reversin 205 比吲哚美辛更有效，表明 ABCB1 蛋白的活性超过 ABCC1 蛋白。在抑制 ABC 转运蛋白的浓度范围内，多药耐药调节剂并未阻止胚胎发育至囊胚阶段。然而，reversin 205 抑制 ABCB1 介导的外排作用，使胚胎对抗有丝分裂长春花生物碱长春碱产生耐药性。与受精后 5 分钟添加 colchicine 相比，预先向卵子中添加 colchicine 能够更有效地阻断胚胎发育。这组结果表明，这些蛋白在海胆胚胎中充当基本的生化屏障，赋予其对有毒异生物的保护生理作用。
