The endometrial cycle in response to hormonal stimulation is essential for implantation. The female has endometrium that repeats this cycle through about half of a lifetime. The cycle includes three phases, proliferative, secretory, and menstrual, and each phase has distinct characteristics. The endometrial stromal cells (EnSCs) in each phase also have specialized characteristics, including cell cycle, morphologies, and cellular metabolic state. So we hypothesized that the cells in each phase have unique mitochondrial morphologies because they are generally linked to cellular metabolic state. To investigate the metabolic characteristics in each phase, we investigated the mitochondrial morphologies by transmission electron microscopy, oxygen consumption rate (OCR), and intracellular adenosine triphosphate (ATP) production. The decidualized EnSCs have shorter mitochondria than those in the proliferative phase. Besides, they also displayed distinct intracellular structural characteristics compared with the proliferative phase, such as ribosome-rich endoplasmic reticulum and increased formation of vesicles. OCR and luminescent ATP detection assay revealed that the basal respiration and ATP production in the decidualized EnSCs were lower than those in the proliferative phase. Thus, we concluded that morphological and intracellular structural changes were induced during the decidualization. Moreover, the decreased mitochondrial length was shown to correlate with decreased dependency on oxidative phosphorylation and ATP concentration in EnSCs.

中文翻译：

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子宫内膜周期期间子宫内膜基质细胞的线粒体和代谢动力学。


子宫内膜周期对激素刺激的反应对于植入至关重要。女性的子宫内膜会在大约一半的一生中重复这个周期。周期包括增殖期、分泌期和月经期三个阶段，每个阶段都有不同的特点。每个阶段的子宫内膜基质细胞（EnSC）也具有特定的特征，包括细胞周期、形态和细胞代谢状态。因此，我们假设每个阶段的细胞都具有独特的线粒体形态，因为它们通常与细胞代谢状态相关。为了研究每个阶段的代谢特征，我们通过透射电子显微镜、耗氧率（OCR）和细胞内三磷酸腺苷（ATP）产生研究了线粒体形态。蜕膜化的 EnSC 的线粒体比增殖期的 EnSC 短。此外，与增殖期相比，它们还表现出明显的细胞内结构特征，例如富含核糖体的内质网和囊泡形成增加。 OCR 和发光 ATP 检测表明，蜕膜化 EnSC 的基础呼吸和 ATP 产量低于增殖期。因此，我们得出结论，在蜕膜化过程中诱导了形态和细胞内结构的变化。此外，线粒体长度的缩短与 EnSC 中氧化磷酸化和 ATP 浓度依赖性的降低相关。