人脐带间充质干细胞联合褪黑素治疗化疗致早发性卵巢功能不全的作用及机制

Therapeutic effects and mechanism of human umbilical cord mesenchymal stem cells combined with melatonin on premature ovarian insufficiency induced by chemotherapy

背景:目前研究证明,人脐带间充质干细胞和褪黑素均可改善卵巢功能,但人脐带间充质干细胞联合褪黑素对化疗所致早发性卵巢功能不全的保护作用及机制尚未有研究报道。目的:探讨人脐带间充质干细胞联合褪黑素对化疗所致早发性卵巢功能不全的保护作用及机制。方法:将动情周期正常的40只Wistar大鼠随机分为对照组、模型组、人脐带间充质干细胞组、褪黑素组和人脐带间充质干细胞+褪黑素组,每组8只。除对照组外,其他组腹腔注射顺铂溶液构建早发性卵巢功能不全大鼠模型,人脐带间充质干细胞组和人脐带间充质干细胞+褪黑素组于造模后第1,6,11天分别尾静脉注射1×10^(6)个人脐带间充质干细胞,褪黑素组和人脐带间充质干细胞+褪黑素组每日腹腔注射10 mg/kg褪黑素,治疗期间监测大鼠体质量和动情周期变化。治疗14 d后,ELISA法检测血清雌二醇、卵泡刺激素、促黄体生成素、抗缪勒管激素水平,计算卵巢指数,苏木精-伊红染色观察卵巢组织学形态,透射电镜观察卵巢颗粒细胞超微结构,Western blot检测PI3K/AKT/mTOR信号通路蛋白和LC3、P62等自噬蛋白在卵巢组织中的表达。结果与结论:(1)与对照组相比,模型组大鼠体质量逐渐减轻、动情周期紊乱,卵巢指数显著下降(P<0.01);雌二醇、抗缪勒管激素水平降低(P<0.01),卵泡刺激素、促黄体生成素水平升高(P<0.01);卵巢组织学形态和卵巢颗粒细胞超微结构严重破坏;p-PI3K/PI3K、p-AKT/AKT、p-mTOR/mTOR和P62蛋白表达显著降低(P<0.01),LC3Ⅱ/Ⅰ蛋白表达显著升高(P<0.001)。(2)与模型组相比,各治疗组大鼠体质量逐渐恢复,部分大鼠动情周期恢复正常,卵巢指数显著升高(P<0.01);雌二醇、抗缪勒管激素水平升高(P<0.05),卵泡刺激素、促黄体生成素水平降低(P<0.05);卵巢组织学形态和卵巢颗粒细胞超微结构显著改善;p-PI3K/PI3K、p-AKT/AKT、p-mTOR/mTOR和P62蛋白表达显著升高(P<0.001),LC3Ⅱ/Ⅰ蛋白表达显著降低(P<0.01)。其中人脐带间充质干细胞+褪黑素组上述指标改善更为显著。结果表明,人脐带间充质干细胞联合褪黑素可能通过上调PI3K/AKT/mTOR信号通路,抑制卵巢颗粒细胞自噬来治疗早发性卵巢功能不全。

BACKGROUND:Current research has shown that human umbilical cord mesenchymal stem cells and melatonin can both improve ovarian function.However,the protective effect and mechanism of human umbilical cord mesenchymal stem cells combined with melatonin on chemotherapy-induced premature ovarian insufficiency have not been reported.OBJECTIVE:To investigate the protective effect and mechanism of human umbilical cord mesenchymal stem cells combined with melatonin on chemotherapyinduced premature ovarian insufficiency.METHODS:Forty Wistar rats with normal estrous cycle were randomly divided into control group,model group,human umbilical cord mesenchymal stem cell group,melatonin group,and human umbilical cord mesenchymal stem cell+melatonin group,with 8 rats in each group.In addition to the control group,the rat model of premature ovarian insufficiency was constructed by intraperitoneal injection of cisplatin solution.The rats in the human umbilical cord mesenchymal stem cell group and the human umbilical cord mesenchymal stem cell+melatonin group were injected with 1×10^(6) human umbilical cord mesenchymal stem cells in the tail vein at 1,6,and 11 days after modeling,respectively.The rats in the melatonin group and human umbilical cord mesenchymal stem cell+melatonin group were injected intraperitoneally with 10 mg/kg melatonin daily.The changes in body mass and estrous cycle of rats were monitored during treatment.After 14 days of treatment,ELISA was used to detect serum levels of estradiol,follicle stimulating hormone,luteinizing hormone,and anti Mullerian hormone.Ovarian index was calculated.Hematoxylin-eosin staining was performed to observe ovarian histological morphology.Ultrastructure of ovarian granulosa cells was observed by transmission electron microscopy.Western blot assay was conducted to detect the expression of PI3K/AKT/mTOR signaling pathway proteins and LC3 and P62 autophagy proteins in ovarian tissues.RESULTS AND CONCLUSION:(1)Compared with the control group,the body mass of rats in the model group decreased gradually,the estrous cycle was disturbed,and the ovarian index decreased significantly(P<0.01).The levels of estradiol and anti-Mullerian hormone were decreased(P<0.01),while the levels of follicle stimulating hormone and luteinizing hormone were increased(P<0.01).The histological morphology and granulosa cell ultrastructure of ovary were seriously damaged.The protein expressions of p-PI3K/PI3K,p-AKT/AKT,p-mTOR/mTOR,and P62 were significantly decreased(P<0.01),while the protein expressions of LC3II/I were significantly increased(P<0.001).(2)Compared with the model group,the body mass of rats in all treatment groups recovered gradually,the estrous cycle of some rats returned to normal,and the ovarian index was significantly increased(P<0.01);the levels of estradiol and anti-Mullerian hormone were increased(P<0.05),while the levels of follicle stimulating hormone and luteinizing hormone were decreased(P<0.05).The histological morphology and ultrastructure of ovary were significantly improved.The protein expressions of p-PI3K/PI3K,p-AKT/AKT,p-mTOR/mTOR,and P62 were significantly increased(P<0.001),while the protein expression of LC3II/I was significantly decreased(P<0.01).Human umbilical cord mesenchymal stem cell+melatonin group showed more significant improvement in the above indexes.The results suggest that human umbilical cord mesenchymal stem cells combined with melatonin may inhibit ovarian granulosa cell autophagy by upregulating PI3K/AKT/mTOR signaling pathway to treat premature ovarian insufficiency.