Apoptosis in embryos of diabetic rats
Apoptosis in embryos of diabetic rats
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DOI：
10.1111/j.1600-0773.1998.tb01452.x
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发表时间：
1998-09-01
期刊：
影响因子：
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通讯作者：
Welsh, N
中科院分区：
文献类型：
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作者：
Forsberg, H;Eriksson, UJ;Welsh, N
本研究旨在探讨妊娠期糖尿病对大鼠胚胎和卵黄囊凋亡的影响。糖尿病大鼠妊娠第12天的严重畸形和发育迟缓胚胎在琼脂糖凝胶上表现出明显的DNA阶梯。另一方面，在对照组和糖尿病大鼠的非畸形胚胎或相应的卵黄囊中均未观察到DNA阶梯。妊娠第10天的胚胎中，TUNEL阳性细胞分布较少，主要分布在尿囊、前肠上皮、颅神经上皮和颅间质。妊娠第12天的胚胎组织显示大量tunel阳性细胞聚集，表明多器官发育重构。对第10天和第12天的非畸形胚胎的分析显示，TUNEL阳性细胞的分布和频率在这两天不受母亲糖尿病状态的影响。正常卵黄囊体外培养（2-8小时）可产生较强的DNA阶梯，但在相应的胚胎中没有。分散的卵泡细胞比分散的胚胎细胞产生更高水平的活性氧。胚胎和卵黄囊细胞中的活性氧水平不受母亲糖尿病状态的影响。此外，免疫印迹分析显示，正常和糖尿病大鼠的胚胎中Bcl-2水平高，caspase-1水平未检测到，相应的卵黄囊中Bcl-2水平低，caspase-1水平高。胚胎的免疫组织化学分析显示，位于tunel阳性细胞附近的一小部分细胞亚群中有caspase-1反应性。我们得出的结论是，与卵黄囊细胞相比，胚胎细胞在体外进入凋亡的固有能力较低，并且广泛的凋亡不太可能在糖尿病诱导的畸形发生中起主要作用，而是在严重畸形和发育迟缓胚胎的早期吸收阶段起主要作用。
The aim of the present study was to determine whether maternal diabetes affects rat embryo and yolk sac apoptosis during the postimplantation period. Severely malformed and growth-retarded embryos of gestational day 12 from diabetic rats exhibited pronounced DNA laddering on agarose gels. On the other hand, no DNA laddering could be observed in any of the non-malformed embryos from control and diabetic rats, or in their corresponding yolk sacs. Analysis of embryos of gestational day 10 revealed only a few scattered TUNEL positive cells mainly located in the allantois, the foregut epithelium, the cranial neuroepithelium and in the cranial mesenchyme. Embryonic tissue of gestational day 12 showed numerous aggregates of TUNEL-positive cells, indicating developmental remodelling of multiple organs. Analysis of non-malformed embryos of day 10 and 12 revealed a distribution and frequency of TUNEL positive cells unaffected by the diabetic state of the mother on both days. In vitro incubation (2-8 hr) of normal day-12 yolk sacs resulted in strong DNA laddering, but not in the corresponding embryos. Dispersed polk sac cells generated higher levels of reactive oxygen species than dispersed embryonic cells. Reactive oxygen species levels in both embryonic and yolk sac cells were unaffected by the diabetic state of the mother. Moreover, immunoblot analysis showed high Bcl-2 and undetectable caspase-1 levels in embryos from both normal and diabetic rats and low Bcl-2 and high caspase-1 levels in the corresponding yolk sacs. Immunohistochemical analysis of embryos demonstrated caspase-1-reactivity in a small subpopulation of cells located in proximity to TUNEL-positive cells. We conclude that the inherent capacity of embryonic cells to enter apoptosis in vitro is low as compared to yolk sac cells, and that wide-spread apoptosis is not likely to play a major role in diabetes-induced dysmorphogenesis but rather in early phases of resorption of severely malformed and developmentally retarded embryos.