Abstract：
This work explored whether a well-characterized recombinant human interleukin-6 (hIL6) protein will influence in vitro produced (IVP) bovine embryo development and survival after cryopreservation. Cumulus oocyte complexes were collected from abattoir derived ovaries, matured for 24 h, and fertilized using pooled semen from Holstein bulls. Embryos were treated with 0, 25, 50, or 100 ng/mL hIL6 on day 5 post-fertilization. An increase in ICM cell numbers was observed in each hIL6 treatment, with the lowest hIL6 treatment having the same magnitude of response as the middle and highest hIL6 concentration. No effects on TE cell numbers were observed. The second study involved cryopreserving (via slow freezing) of hIL6-treated blastocysts, then examining post-thaw blastocyst survival by incubating for 24 h in the absence of hIL6 treatments. Blastocyst re-expansion and hatching rates were unaffected by any of the IL6 treatments, however, increases in both ICM and TE cell numbers were detected at 24 h post-thawing in blastocysts exposed to 100 ng/mL hIL6 but not lower concentrations before freezing. A reduction in the percentage of TUNEL-positive TE cells was observed after thawing in blastocysts exposed to 25, 50 and 100 ng/mL hIL6 before cryopreservation. No treatment-dependent changes in TUNEL-positive ICM cells were observed. In summary, hIL6 supplementation improves ICM cell numbers in bovine blastocysts to a degree that is commensurate with what has been observed when using bovine recombinant IL6. This positive effect of hIL6 on ICM cell numbers is maintained after freezing and thawing, and a novel improvement in post-thaw TE cell numbers occur in hIL6 treated embryos. This positive effect on TE cell numbers is attributed, at least in part, to an hIL6-dependent reduction in TE cell apoptosis.
摘要：
这项工作探讨了特征明确的重组人白介素6（hIL6）蛋白是否会影响冷冻保存后的体外生产（IVP）牛胚胎发育和存活。从屠宰场衍生的卵巢收集卵丘卵母细胞复合物，成熟24小时，用荷斯坦公牛的精液受精。在受精后第5天用0、25、50或100ng/mLhIL6处理胚胎。在每个hIL6处理中观察到ICM细胞数量的增加，最低的hIL6处理具有与中等和最高hIL6浓度相同的响应幅度。未观察到对TE细胞数量的影响。第二项研究涉及冷冻保存（通过缓慢冷冻）hIL6处理的胚泡，然后通过在没有hIL6处理的情况下孵育24小时来检查解冻后胚泡的存活率。囊胚再扩张和孵化率不受任何IL6治疗的影响，然而,在暴露于100ng/mLhIL6的胚泡解冻后24小时检测到ICM和TE细胞数量的增加，但在冷冻前没有降低浓度。在冷冻保存前暴露于25、50和100ng/mLhIL6的胚泡中解冻后,观察到TUNEL阳性TE细胞的百分比降低。未观察到TUNEL阳性ICM细胞的治疗依赖性变化。总之,hIL6补充将牛胚泡中的ICM细胞数量提高到与使用牛重组IL6时所观察到的相当的程度。HIL6对ICM细胞数量的这种积极作用在冷冻和解冻后保持，在hIL6处理的胚胎中，解冻后TE细胞数量出现了新的改善。这种对TE细胞数量的积极影响归因于，至少在某种程度上,TE细胞凋亡的hIL6依赖性减少。
