Mechanism of action of flavopiridol to improve polycystic ovary syndrome by remodeling intestinal flora and regula-ting PI3K/AKT signaling pathway

Yang Yuqi; Wu Lina; Sun Ke; Xing Weiyuan; Hou Yue; Zhang Liwen

doi:10.3969/j.issn.1671-6450.2024.03.018

Abstract：Objective To investigate the regulatory effect of BBR on the intestinal flora of mice with polycystic o-vary syndrome(PCOS)and its therapeutic mechanism.Methods In June 2021-June 2022,experiments were carried out in the Experimental Animal Center of Shanghai Fifth People's Hospital Affiliated to Fudan University,24 clean-grade healthy fe-male C57BL/6J mice,6 mice were randomly selected as the normal control group,and the remaining 18 mice were used to prepare the PCOS model by letrozole gavage.After successful modeling,the modeled mice were randomly divided into the model(PCOS)group,the positive drug daunin-35(0.2 mg·kg-1·d-1)group and the BBR(100·kg-1·d-1)groups,6 mice in each group,were given the corresponding drugs for 14 d.Feces were collected from the colon of the mice,and 16S rDNA sequencing was used to detect intestinal flora;mice were weighed,and morphological changes of vaginal exfoliated cells were observed;serum sex hormone and insulin levels were detected;HE staining was used to observe the pathological structure of the ovary;immunohistochemistry was used to detect the expression of Claudin-1 and Occludin in the colon of mice;and Western-blot was used to detect the expression of proteins related to the PI3K/AKT pathway in the ovary tis-sues.Results The 16S rDNA sequencing showed that the diversity of intestinal flora in the PCOS group was changed compared with that in the normal control group.At the genus level,the abundance of harmful bacteria such as Blautia,Fu-sobacterium spp.,Coccidioides immitis,Coccidioides twins and Clostridium spp.was increased in the PCOS group compared with the normal control group,while the disordered state of the intestinal flora of the mice was improved by BBR,and the abundance of beneficial bacteria,such as Lactobacillus spp.,was increased.Compared with the normal control group,mice in the PCOS group had reduced levels of estradiol(E2),follicle-stimulating hormone(FSH),and insulin sensitivity index(ISI)(t/P=2.847/0.017,3.079/0.012,3.541/0.005),body mass and testosterone(T),luteinizing hormone(LH),LH/FSH,fasting glucose(FPG),fasting insulin(FINS),and insulin resistance index(HOMA-IR)levels were elevated(t/P=4.782/0.013,4.626/0.001,5.703/<0.001,and 2.578/0.028,4.156/0.002,3.255/0.009,7.439/<0.001),disturbances in the motility cycle,light microscopic ovarian structures consistent with PCOS pathology,and decreased expression of Claudin-1,Occludin,p-PI3K/PI3K,and p-AKT/AKT(t/P=3.806/0.003,3.795/0.004,13.474/<0.001,17.285/<0.001).Compared with the PCOS group,E2,FSH,and ISI levels were elevated(t/P=2.389/0.038,3.354/0.007,3.198/0.010),and body mass and T,LH,LH/FSH,FINS,and HOMA-IR lev-els were decreased in the darbepoetin-35 group(t/P=3.133/0.011,3.416/0.007,4.596/0.001,2.327/0.042,2.908/0.016,6.096/<0.001),improved motility cycle and ovarian structure,Claudin-1,Occludin,p-PI3K/PI3K and p-AKT/AKT expression was el-evated(t/P=2.390/0.038,2.247/0.048,7.323/<0.001,7.564/<0.001);BBR group ISI levels were elevated(t/P=3.198/0.010),and body mass and T,LH,LH/FSH,FPG,FINS,HOMA-IR levels were decreased(t/P=3.668/0.004,4.602/0.001,6.101/<0.001,2.535/0.030,5.950/<0.001,2.914/0.015,7.630/<0.001),improved motility cycle and ovarian structure,improved levels of Clau-din-1,Occludin,p-PI3K/PI3K and p-AKT/AKT expression was elevated(t/P=3.799/0.003,3.185/0.010,7.473/<0.001,8.187/<0.001).Conclusion Letrozole-induced PCOS mice have dysbiosis,BBR may help to activate the PI3K/AKT pathway and improve the intestinal barrier function by regulating the distribution of intestinal flora to achieve the therapeutic purpose of PCOS.