Hsu Keng-Fu, Pan Hsien-An, Hsu Yu-Yun, Wu Ching-Ming, Chung Wen-Ju, Huang Soon-Cen
Department of Obstetrics and Gynecology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Department of Nursing, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Taiwan J Obstet Gynecol. 2014 Sep;53(3):293-302. doi: 10.1016/j.tjog.2013.01.030.
To understand the mechanisms of postpartum uterine involution, we investigated the uterine myometrial changes during pregnancy and the postpartum period.
Nine groups of uterine myometrial samples from mice (n = 4) were collected on gestational Day 0 (nonpregnant), Day 1, Day 2, Day 7, Day 14, and Day 21 and on postpartum Day 1, Day 2, and Day 7. Human samples of uterine myometrium on term (n = 1) and postpartum Day 1 (n = 2) were also collected. Ki-67 immunostaining was used to determine myometrial proliferation. For cell hypertrophy analysis, organelle proteins, β-actin, prohibin, calnexin, and golgin-97 were analyzed by Western blotting. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and evaluation of activated caspase-3 expression by Western blot analysis assay were used to detect apoptosis. Autophagy was assayed via the evaluation of LC3 expression by Western blotting, immunohistochemistry, and autophagosomes by electron microscopy.
Uterine myocytes proliferated during the early stage of gestation with a peak at Day 2, whereas myocyte hypertrophy with increased cellular organelle production occurred gradually in later stages of pregnancy. Postpartum autophagy developed abruptly in uterine myocytes without obvious apoptosis.
Autophagy of myocytes may play an important role in uterine involution. These results have implications for our understanding of myometrial functional adaptations during pregnancy and the physiological role of autophagy in the uterine remodeling events in the postpartum period.
为了解产后子宫复旧的机制，我们研究了妊娠期间及产后子宫肌层的变化。
收集来自小鼠（n = 4）的九组子宫肌层样本，分别在妊娠第0天（未孕）、第1天、第2天、第7天、第14天、第21天以及产后第1天、第2天和第7天采集。还收集了足月时（n = 1）和产后第1天（n = 2）的人子宫肌层样本。采用Ki-67免疫染色来确定肌层增殖情况。对于细胞肥大分析，通过蛋白质免疫印迹法分析细胞器蛋白、β-肌动蛋白、抑制素、钙连蛋白和高尔基体蛋白97。采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法（TUNEL）以及通过蛋白质免疫印迹分析检测活化的半胱天冬酶-3表达来检测细胞凋亡。通过蛋白质免疫印迹法、免疫组织化学法评估LC3表达以及通过电子显微镜观察自噬体来检测自噬。
子宫肌细胞在妊娠早期增殖，在第2天达到峰值，而在妊娠后期细胞肥大并伴有细胞器产生增加逐渐发生。产后子宫肌细胞中自噬突然出现，无明显凋亡。
肌细胞自噬可能在子宫复旧中起重要作用。这些结果有助于我们理解妊娠期间肌层的功能适应性以及自噬在产后子宫重塑事件中的生理作用。
