Effects of oxidative stress and inhibitors of the pentose phosphate pathway on sexually dimorphic production of IFN-τ by bovine blastocysts
Effects of oxidative stress and inhibitors of the pentose phosphate pathway on sexually dimorphic production of IFN-τ by bovine blastocysts
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DOI：
10.1002/mrd.20053
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发表时间：
2004-05-01
影响因子：
2.5
通讯作者：
Roberts, RM
中科院分区：
文献类型：
--
作者：
Kimura, K;Spate, LD;Roberts, RM
牛干扰素-tau（IFN-tau）是由反刍动物的孕体分泌的抗黄体溶解因子，是常染色体基因的产物，然而体外产生（IVP）的雌性扩张囊胚（EB）分泌约两倍于雄性的IFN-tau。两种可能的解释在这里得到了验证。一个是一种性别的胚胎对氧化应激的敏感性不同。第二个是女性EB产生更多的IFN-tau，因为延迟的X染色体失活导致戊糖磷酸途径（PPP）活性升高。将IVP牛受精卵培养至8细胞期，并置于旨在促进氧化应激（+/-H2 O2; 20 vs. 5% O-2）或抑制葡萄糖6-磷酸脱氢酶（G6 PDH）活性（向培养基中添加脱氢表雄酮DHEA或6-氨基烟酰胺6-AN）的条件下。在第8天，将胚泡单独培养另外48小时以评估IFN-tau产生，并回顾性地确定胚胎性别。H_2O_2（200 μ M）和20%O ~（-2）的存在下，囊胚数量减少（P <0.05），囊胚继续发育受损（P < 0.05），但IFN-tau的产生和IFN-tau的性二态表达均未受到影响。IFN-tau的产生减少，特别是在雌性中（P < 0.05），并且在DHEA（100 μ M）和6-AN（1 μ M）存在下，产生的两性异形差异消失。在6-AN的情况下，这些效果在囊胚发育进程、质量或细胞数量没有显著下降的情况下实现。这些数据表明，女性EB产生更高的IFN-tau是PPP途径氧化臂活性增加的间接结果。(C)2004 Wiley-Liss，Inc.
Bovine interferon-tau (IFN-tau), the anti-luteolytic factor secreted by conceptuses of pecoran ruminants, is a product of autosomal genes, yet in vitro produced (IVP) female expanded blastocysts (EB) secrete about twice as much IFN-tau as males. Two possible explanations have been tested here. One is that embryos of one sex are differentially susceptible to oxidative stress. The second is that female EB produce more IFN-tau because pentose-phosphate pathway (PPP) activity is elevated as a result of delayed X-chromosome inactivation. IVP bovine zygotes were cultured to the 8-cell stage and placed under conditions designed either to promote oxidative stress (+/-H2O2; 20 vs. 5% O-2), or to inhibit glucose 6-phosphate dehydrogenase (G6PDH) activity (addition of dehydroepiandrosterone, DHEA or 6-aminonicotinamide, 6-AN to the medium). At day 8, blastocysts were cultured individually for a further 48 hr to assess IFN-tau production, and embryo sex determined retrospectively. Blastocyst numbers were reduced (P < 0.05) and their continued development impaired (P < 0.05) in presence of H2O2 (200 muM) and 20% O-2, but neither IFN-tau production nor sexually dimorphic expression of IFN-tau were affected. IFN-tau production was reduced, particularly in females (P < 0.05), and sexual dimorphic differences in production were lost in the presence of both DHEA (100 muM) and 6-AN (1 muM). In the case of 6-AN, these effects were achieved without a significant decline in blastocyst developmental progression, quality, or cell number. The data suggest that the higher production of IFN-tau by female EB is an indirect outcome of the increased activity of the oxidative arm of the PPP pathway. (C) 2004 Wiley-Liss, Inc.