高脂饮食诱导的肥胖早孕小鼠子宫内膜蜕膜反应受损

目的： 探讨高脂饮食诱导的肥胖对小鼠子宫内膜蜕膜反应的影响。 方法： 将12只4周龄健康C57BL/6J雌性小鼠随机分为高脂组和对照组（每组6只），分别饲喂高脂 （22?kJ/g）、 正常 （16?kJ/g） 饲料12周。每周测量小鼠体重，喂养12周后测量小鼠体长、体宽并检测空腹血清三酰甘油和总胆固醇水平。将雌鼠与健康C57BL/6J雄鼠合笼交配，收集妊娠第7天子宫组织，采用苏木精-伊红染色观察子宫内膜细胞形态，Masson染色观察子宫内膜胶原纤维；采用免疫组织化学法、蛋白质印迹法检测子宫内膜蜕膜反应相关蛋白表达。分离原代小鼠子宫内膜基质细胞，油酸、棕榈酸模拟高脂环境进行干预，雌二醇、孕酮诱导细胞发生蜕膜反应后，油 红O、 Bodipy染色观察脂滴累积情况，鬼笔环肽染色观察细胞骨架，实时荧光定量PCR、蛋白质印迹法检测蜕膜反应相关标志物的基因和蛋白表达。 结果 ：饲养12周后，高脂组体重明显高于对照组（ P <0.01），两组体长无明显差异（ P >0.05），但高脂组体宽显著大于对照组（ P <0.01），血清三酰甘油和总胆固醇水平均显著高于对照组（均 P <0.05）。高脂组胚胎着床数显著少于对照组（ P <0.01），高脂组子宫内膜基质细胞向蜕膜细胞转换缓慢且形态异常，蜕膜反应标志物骨形成蛋白（BMP）2、同源异形框A10（HOXA10）表达水平均低于对照组，其中两组HOXA10表达水平差异有统计学意义（ P <0.01）。油红O、Bodipy染色结果显示，原代小鼠子宫内膜基质细胞经高脂处理后，脂滴堆积明显增多，鬼笔环肽染色发现其细胞骨架形态异常，蜕膜反应相关基因 dtprp 、 HOXA10 以及蛋白BMP2、HOXA10、环氧合酶2的表达水平均明显低于对照组（均 P <0.05）。 结论 ：高脂饮食诱导的肥胖会损伤小鼠子宫内膜的蜕膜反应。

Impairment of endometrial decidual reaction in early pregnant mice fed with high fat diet

Objective: To investigate the effect of obesity induced by high fat diet on decidual reaction of endometrium in mice, and the effect of high fat treatment on decidual reaction of endometrial stromal cells. Methods: Twelve 4-week-old healthy C57BL/6J female mice were randomly divided into high fat diet group and control group with 6 mice in each group. They were fed with high fat diet (22?kJ/g) or normal diet (16?kJ/g) for 12 weeks, respectively. The body weight of mice was measured every week. After feeding for 12 weeks, the body length and width of mice were measured, and the levels of fasting serum triglyceride and total cholesterol were determined. Then the mice were mated with healthy C57BL/6J male mice, and the uterine tissues were collected on the seventh day of pregnancy. The decidual cells and collagen fibers in mouse endometrium was observed by HE staining and Masson staining respectively. The expression of decidual reaction related proteins in mouse endometrium were detected by immunohistochemistry and Western blotting. Mouse endometrial stromal cells (mESCs) were isolated and treated with the oleic acid and palmitic acid in vitro , and the decidual reaction was induced with estradiol and progesterone. The accumulation of lipid droplets in mESCs was observed by oil red O and Bodipy staining. The cytoskeleton of mESCs was observed by phalloidin staining. The levels of decidual reaction related genes and proteins were detected by real-time fluorescence quantitative PCR and Western blotting. Results: After feeding for 12 weeks, the body weight of mice in the high fat group was significantly higher than that in the control group ( P <0.01), and there was no significant difference in body length between two groups ( P >0.05), but the body width of mice in the high fat group was significantly larger than that in the control group ( P <0.01), and the levels of serum triglyceride and total cholesterol were significantly higher than those in the control group (Both P <0.05). The number of embryo implantation in the high fat group was significantly less than that in the control group ( P <0.01). The differentiation of mESCs to decidual cells in high fat group was slow and abnormal. The expression levels of decidual reaction markers bone morphogenetic protein (BMP)2 and homeobox A10 (HOXA10) were lower than those in the control group, and there was significant difference in the expression level of HOXA10 ( P <0.01). The results of oil red O and Bodipy staining in mESCs showed that after high fat treatment, the accumulation of lipid droplets increased significantly, phalloidin staining showed abnormal cytoskeleton morphology. The expression levels of decidual reaction related genes dtprp , HOXA10 and proteins BMP2, HOXA10 and cyclooxygenase (COX)2 were significantly lower than those in the control group ( P <0.05). Conclusion: Obesity induced by high fat diet and high fat treatment can impair the decidual reaction of endometrium and endometrial stromal cells in mice.