基于PTEN/PI3K/Akt信号通路探讨归芍运脾汤防治乳腺增生的机制

Mechanism of Guishao Yunpi Decoction in Prevention and Treatment of Mammary Gland Hyperplasia Based on PTEN/PI3K/Akt Signaling Pathway

目的:基于磷酸酯酶与张力蛋白同源物(PTEN)/磷脂酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)通路研究归芍运脾汤防治乳腺增生大鼠的作用机制。方法:将70只SPF级SD大鼠随机分为正常组(n=15)和造模组(n=55),造模组大鼠采用综合造模法(饥饱失常法+夹尾刺激法+苯甲酸雌二醇+黄体酮)复制乳腺增生模型,随后各取5只进行模型验证。模型复制成功后将造模组大鼠随机分为模型组、枸橼酸他莫昔芬组和归芍运脾汤高、中、低剂量组,共5组,每组10只。正常组和模型组大鼠给予10 mL·kg^(-1)·d^(-1)蒸馏水灌胃,归芍运脾汤高、中、低剂量组分别给予17.2、8.6、4.3 g·kg^(-1)·d^(-1)归芍运脾汤汤剂灌胃,枸橼酸他莫昔芬组给予4 mg·kg^(-1)·d-1枸橼酸他莫昔芬灌胃,治疗30 d后观察大鼠一般生存状况,采用超声诊断仪测定乳腺组织厚度,采用旷场实验阳性反应进行行为学评价,采用酶联免疫吸附测定法(ELISA)测定乳腺组织中B细胞淋巴瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)的含量,采用实时荧光定量聚合酶链式反应(Real-time PCR)检测乳腺组织中PTEN、PI3K、Akt mRNA表达水平,采用蛋白免疫印迹法(Western blot)检测PTEN、PI3K、Akt、磷酸化(p)-Akt蛋白表达水平。结果:与正常组比较,模型组大鼠暴躁易激惹,扎堆蜷卧,旷场实验反应阳性,乳头肿胀明显,乳腺厚度明显增加(P<0.05);乳腺组织中Bcl-2含量明显升高、Bax含量明显降低(P<0.05),乳腺组织中PTEN mRNA表达水平明显降低,PI3K、Akt mRNA表达水平明显升高(P<0.05),PTEN、PI3K、Akt蛋白表达水平与mRNA基本一致;与模型组比较,各给药组大鼠一般生存状态、乳头肿胀程度不同程度缓解,旷场实验反应阳性不同程度改善,乳腺厚度变薄(P<0.05),乳腺组织中Bcl-2含量明显降低、Bax含量明显升高(P<0.05),乳腺组织中PTEN mRNA表达水平明显升高,PI3K、Akt mRNA表达水平明显降低(P<0.05),PTEN、PI3K和Akt蛋白表达水平与mRNA基本一致。结论:归芍运脾汤能够有效改善乳腺增生大鼠一般生存状况,减轻乳腺增生程度,其具体机制可能与归芍运脾汤有效调控PTEN/PI3K/Akt通路而实现。

Objective:Study on the mechanism of Guishao Yunpi decoction in preventing and treating breast hyperplasia based on phosphatase and tensin homolog(PTEN)/phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)pathway.Method:Seventy SPF-grade SD rats were randomly assigned into blank group(n=15)and modeling group(n=55).The mammary gland hyperplasia model of liver stagnation and spleen deficiency was established by the comprehensive modeling method(hunger and satiety abnormality+tail stimulation+estradiol benzoate+progesterone),and then 5 rats were randomly selected for model verification.The modeled rats were then randomly assigned into five groups:model group,positive control(4 mg·kg^(-1)·d^(-1) tamoxifen)group,and high-,medium-,and low-dose(17.2,8.6,4.3 g·kg^(-1)·d^(-1),respectively)Guishao Yunpi decoction groups,with 10 rats in each group.The rats in the blank group and model group were given 10 mL·kg^(-1)·d^(-1) distilled water,and those in other groups were orally administrated with corresponding drugs.After 30 days of treatment,the general living conditions of rats were observed,and the thickness of breast tissue was measured by an ultrasonic diagnostic instrument.The open field test was carried out for behavioral evaluation.The levels of B-cell lymphoma-2(Bcl-2)and Bcl-2-associated X(Bax)in the breast tissue were determined by enzyme-linked immunosorbent assay(ELISA).The mRNA and protein levels of PTEN,PI3K,and Akt in the breast tissue were determined by Real-time fluorescence quantitative polymerase chain reaction(Real-time PCR)and Western blot,respectively.Result:Compared with those in the blank group,the rats in the model group were irritable,curled up in clusters,and showed positive behavior in the open field test.The modeling led to nipple swelling and increased the breast thickness(P<0.05).Moreover,the modeling elevated the level of Bcl-2 and lowered that of Bax in the breast tissue(P<0.05),down-regulated the mRNA and protein levels of PTEN,and up-regulated the mRNA and protein levels of PI3K and Akt(P<0.05).Compared with the model group,drug administration relieved the general survival state,the degree of nipple swelling,and the positive behavior in the open field test and reduced the breast thickness(P<0.05).In addition,drug administration reduced the level of Bcl-2 and increased that of Bax in the breast tissue(P<0.05),up-regulated the mRNA and protein levels of PTEN,and down-regulated the mRNA and protein levels of PI3K and Akt(P<0.05).Conclusion:Guishao Yunpi decoction can improve the general living conditions and alleviate the mammary gland hyperplasia of rats with the syndrome of liver depression and spleen deficiency,which may be realized by the regulation of the PTEN/PI3K/Akt pathway.