Treatment with metformin and sorafenib alleviates endometrial hyperplasia in polycystic ovary syndrome by promoting apoptosis via synergically regulating autophagy

Effect of berberine combined with metformin on autophagy in polycystic ovary syndrome by regulating AMPK/AKT/mTOR pathway

The pathologic mechanism of polycystic ovary syndrome (PCOS) is related to increased autophagy of granulosa cells. Both berberine and metformin have been shown to improve PCOS, but whether the combination of berberine and metformin can better improve PCOS by inhibiting autophagy remains unclear. PCOS models were constructed by injecting dehydroepiandrosterone into rats, and berberine, metformin or berberine combined with metformin was administered to rats after modeling. Rats' body weight and ovarian weight were measured before and after modeling. Histopathological examination of ovarian tissue and estrous cycle analysis of rats were performed. Insulin resistance, hormone levels, oxidative stress, and lipid metabolism in PCOS rats were assessed. Expression of the AMPK/AKT/mTOR pathway and autophagy-related proteins was analyzed by Western blot assays. Granulosa cells were isolated from rat ovarian tissue and identified by immunofluorescence staining followed by transmission electron microscopy analysis. Berberine combined with metformin reduced the body weight and ovarian weight of PCOS rats, increased the number of primordial and primary follicles, decreased the number of secondary and atretic follicles, normalized the estrous cycle, and improved insulin resistance, androgen biosynthesis, oxidative stress and lipid metabolism disorders, and increased estrogen production. In addition, berberine combined with metformin reduced the number of autophagosomes in granulosa cells, which may be related to AMPK/AKT/mTOR pathway activation, decreased Beclin1 and LC3II/LC3I levels, and increased p62 expression. Berberine combined with metformin could inhibit autophagy by activating the AMPK/AKT/mTOR pathway in PCOS, indicating that berberine combined with metformin is a potential treatment strategy for PCOS.

Follicle stimulating hormone controls granulosa cell glutamine synthesis to regulate ovulation

Polycystic ovary syndrome (PCOS) is the leading cause of anovulatory infertility. Inadequate understanding of the ovulation drivers hinders PCOS intervention. Herein, we report that follicle stimulating hormone (FSH) controls follicular fluid (FF) glutamine levels to determine ovulation. Murine ovulation starts from FF-exposing granulosa cell (GC) apoptosis. FF glutamine, which decreases in pre-ovulation porcine FF, elevates in PCOS patients FF. High-glutamine chow to elevate FF glutamine inhibits mouse GC apoptosis and induces hormonal, metabolic, and morphologic PCOS traits. Mechanistically, follicle-development-driving FSH promotes GC glutamine synthesis to elevate FF glutamine, which maintain follicle wall integrity by inhibiting GC apoptosis through inactivating ASK1-JNK apoptotic pathway. FSH and glutamine inhibit the rapture of cultured murine follicles. Glutamine removal or ASK1-JNK pathway activation with metformin or AT-101 reversed PCOS traits in PCOS models that are induced with either glutamine or EsR1-KO. These suggest that glutamine, FSH, and ASK1-JNK pathway are targetable to alleviate PCOS.

Juan-tong-yin potentially impacts endometriosis pathophysiology by enhancing autophagy of endometrial stromal cells via unfolded protein reaction-triggered endoplasmic reticulum stress

ETHNOPHARMACOLOGICAL RELEVANCE

Endometriosis (EMs) is characterized by inflammatory lesions, dysmenorrhea, infertility, and chronic pelvic pain. Single-target medications often fail to provide systemic therapeutic results owing to the complex mechanism underlying endometriosis. Although traditional Chinese medicines-such as Juan-Tong-Yin (JTY)-have shown promising results, their mechanisms of action remain largely unknown.

AIM OF THE STUDY

To elucidate the therapeutic mechanism of JTY in EMs, focusing on endoplasmic reticulum (ER) stress-induced autophagy.

MATERIALS AND METHODS

The major components of JTY were detected using high-performance liquid chromatography-mass spectrometry (HPLC-MS). The potential mechanism of JTY in EMs treatment was predicted using network pharmacological analysis. Finally, the pathogenesis of EMs was validated in a clinical case-control study and the molecular mechanism of JTY was validated in vitro using endometrial stromal cells (ESCs).

RESULTS

In total, 241 compounds were analyzed and identified from JTY using UPLC-MS. Network pharmacology revealed 288 targets between the JTY components and EMs. Results of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses indicated that regulating autophagy, migration, apoptosis, and inflammation were the key mechanisms of JTY in treating EMs. Meanwhile, we found that protein kinase R-like endoplasmic reticulum kinase (PERK), Beclin-1, and microtubule-associated protein light chain 3 B (LC3B) expressions were lower in endometria of patients with EMs than in those with normal eutopic endometria (p < 0.05). Additionally, during in vitro experiments, treatment with 20% JTY-containing serum significantly suppressed ESC proliferation, achieving optimal effects after 48 h. Electron microscopy revealed significantly increased autophagy flux in the JTY group compared with the control group. Moreover, JTY treatment significantly reduced the migratory and invasive abilities of ESCs and upregulated protein expression of PERK, eukaryotic initiation factor 2α (eIF2α)/phospho-eukaryotic initiation factor 2α (p-eIF2α), activating Transcription Factor-4 (ATF4), Beclin-1, and LC3BII/I, while subsequently downregulating NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and interleukin 18 (IL-18) expression. However, administration of GSK2656157-a highly selective PERK inhibitor-reversed these changes.

CONCLUSION

JTY ameliorates EMs by activating PERK associated with unfolded protein reaction, enhancing cell ER stress and autophagy, improving the inflammatory microenvironment, and decreasing the migration and invasion of ESCs.

The effective compounds and mechanisms of Cang-Fu-Dao-Tan Formula in treating polycystic ovary syndrome based on UPLC/Q-TOF-MS/MS, network pharmacology and molecular experiments

BACKGROUND

Polycystic ovary syndrome (PCOS), as a common endocrine disease in reproductive-age women, which is characterized by both reproductive and metabolic disorders. Cang-Fu-Dao-Tan Formula (CFDTF) is an effective and relatively safe treatment for PCOS. However, the underlying mechanism is poorly understood.

PURPOSE

To explore the effective compounds and mechanisms of CFDTF in treating PCOS based on UPLC/Q-TOF-MS/MS, network pharmacology and molecular experiments.

METHODS

The UPLC/Q-TOF-MS/MS and TCMSP, SwissTargetPrediction databases were used to identify the active ingredients of CFDTF. Then GeneCards, Disgenet, Drugbank databases were used to obtain the PCOS related targets. Based above, the Drug-component-target (D-C-T) network and protein-protein-interaction (PPI) network were built to analysis the key targets. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis were performed to find the potential mechanisms. Finally, molecular docking analysis, molecular dynamics (MD) simulations and molecular experiments were used to confirm the interactions among the active compounds, targets and explore the potential mechanisms.

RESULTS

A total of 20 compounds were identified by UPLC/Q-TOF-MS/MS, and 136 active compounds by TCMSP from CFDTF. After removing the duplicate results, there were 370 targets related to both CFDTF and PCOS, among which, MAPK3, AKT1, RELA, EGF, TP53 and MYC were proved to have high interactions with the components. The mechanisms of CFDTF against PCOS were related to PI3K-Akt, mTOR, MAPK signaling pathways, and the in vitro experiments proved that the CFDTF positively regulated the cell proliferation and inhibited the apoptosis levels in PCOS cell model.

CONCLUSIONS

The combination of UPLC/Q-TOF-MS/MS, systematic network pharmacology and molecular experiments identified that the quercetin, hesperidin, and glycyrrhizin disaccharide are the TOP 3 effective compounds of CFDTF in treating PCOS and the potential mechanisms may involve in regulating proliferation and apoptosis of granulosa cells.

Synergistic Action of Virgin Coconut Oil and Clomiphene in Reversing Endocrine Dysregulation in Letrozole-Model of Polycystic Ovarian Syndrome in Rats: Role of Nrf2/HMOX-1 Pathway

Polycystic ovarian syndrome (PCOS) is an endocrine disorder in women's reproductive age. Currently, the pathophysiology of PCOS is unclear, and the limited treatment options are unsatisfactory. Virgin coconut oil (VCO) is functional food oil associated with pharmacological effects in reproductive disorders. Therefore, we aimed to evaluate whether VCO could enhance clomiphene (CLO) therapy against PCOS in female rats. Rats were randomly divided: (1) Control, (2) PCOS model, (3) PCOS + CLO, (4) PCOS + VCO, and (5) PCOS + CLO + VCO. The PCOS was induced via daily letrozole (1 mg/kg, orally) administration for 21 days. After the PCOS induction, CLO, VCO, and CLO + VCO were administered from days 22 to 36. Serum levels of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, estrogen, progesterone, and prolactin were estimated. Polymerase chain reaction gene expression for nuclear factor-erythroid-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), catalase (CAT), glutathione reductase (GSR), LH receptor (LHr), androgen receptor (AR), tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and caspase-3 were analyzed. The letrozole-induced PCOS caused considerable increases in GnRH, LH, prolactin, estrogen, and testosterone, whereas FSH decreased significantly compared to the control. The gene expression of Nrf2, HO-1, CAT, and GSR were markedly diminished, while IL-1β, TNF-α, caspase-3, AR, and LHr prominently increased compared to control. Interestingly, the CLO and VCO separately exerted anti-inflammatory and endocrine balance effects. However, VCO-enhanced CLO effect in LH, prolactin and testosterone, Nrf2, HO-1, CAT, GSR, and AR. VCO may synergize with CLO to depress hyperandrogenism and oxidative inflammation in PCOS.

Clinical and metabolic characteristics of endometrial lesions in polycystic ovary syndrome at reproductive age

BACKGROUND

We aimed to explore the clinical and metabolic characteristics in polycystic ovary syndrome (PCOS) patients with different endometrial lesions.

METHODS

234 PCOS patients who underwent hysteroscopy and endometrial biopsy were categorized into four groups: (1) normal endometrium (control group, n = 98), (2) endometrial polyp (EP group, n = 92), (3) endometrial hyperplasia (EH group, n = 33), (4) endometrial cancer (EC group, n = 11). Serum sex hormone levels, 75 g oral glucose tolerance test, insulin release test, fasting plasma lipid, complete blood count and coagulation parameters were measured and analyzed.

RESULTS

Body mass index and triglyceride level of the EH group were higher while average menstrual cycle length was longer in comparison with the control and EP group. Sex hormone-binding globulin (SHBG) and high density lipoprotein were lower in the EH group than that in the control group. 36% of the patients in the EH group suggested obesity, higher than the other three groups. Using multivariant regression analysis, patients with free androgen index > 5 had higher risk of EH (OR 5.70; 95% CI 1.05-31.01), while metformin appeared to be a protective factor for EH (OR 0.12; 95% CI 0.02-0.80). Metformin and hormones (oral contraceptives or progestogen) were shown to be protective factors for EP (OR 0.09; 95% CI 0.02-0.42; OR 0.10; 95% CI 0.02-0.56). Hormones therapy appeared to be a protective factor for EC (OR 0.05; 95% CI 0.01-0.39).

CONCLUSION

Obesity, prolonged menstrual cycle, decreased SHBG, and dyslipidemia are risk factors for EH in patients with PCOS. Oral contraceptives, progestogen and metformin are recommended for prevention and treatment of endometrial lesions in PCOS patients.

Fibroblast growth factor 1 ameliorates thin endometrium in rats through activation of the autophagic pathway

Background: Thin endometrium is a reproductive disorder that affects embryo implantation. There are several therapies available for this disease, however they are not so effective. Fibroblast growth factor 1 (FGF1) is a member of fibroblast growth factor superfamily (FGFs), and it has been demonstrated that FGF1 expression was altered in samples collected from patients with thin endometrium. However, it is unclear if FGF1 could improve thin endometrium. The aim of this study was to investigate whether FGF1 have a therapeutic effect on thin endometrium. Methods: A model of thin endometrium induced by ethanol was constructed to investigate the effect and mechanism of action of FGF1 in thin endometrium. In the characterization experiments, 6-8 weeks female rats (n = 40) were divided into four groups: i) Control group; ii) Sham group; iii) Injured group; (iv) FGF1 therapy group. Endometrial tissues would be removed after three sexuel cycles after molding. Morphology and histology of the endometrium were evaluated by visual and hematoxylin and eosin staining. Masson staining and expression of α-SMA in endometrium showed the degree of endometrial fibrosis. Western blotting (PCNA、vWF and Vim) and immunohistochemistry (CK19 and MUC-1) demonstrated the effect of FGF1 on cell proliferation and angiogenesis. Moreover, immunohistochemistry (ER and PR) was used to explore the function of endometrium. The remaining rats (n = 36) were divided into three groups: i) Injured group; ii) FGF1 therapy group; and iii) 3-methyladenine. Western blotting (p38、p-p38、PI3K 、SQSTM1/p62、beclin-1 and LC3) was used to explore the mechanisms of FGF1. Results: In FGF1 therapy group, the morphology and histology of endometrium improved compared with the model group. Masson staining and the expression level of α-SMA showed that FGF1 could decrease the fibrotic area of endometrium. Besides, changes in ER and PR expression in the endometrium suggested that FGF1 could restore endometrium-related functions. Western blotting and immunohistochemistry revealed that PCNA, vWF, Vim, CK19 and MUC-1 were significantly increased after FGF1 treatment compared with the thin endometrium. In addition, Western blotting showed that p38, p-p38, PI3K, SQSTM1/p62, beclin-1 and LC3 levels were higher in FGF1 group than in the injured group. Conclusion: FGF1 application cured the thin endometrium caused by ethanol through autophagy mechanism.

Therapeutic Effects of Silibinin Against Polycystic Ovary Syndrome Induced by Letrozole in Rats via Its Potential Anti-Inflammatory and Anti-Oxidant Activities

Background

Current therapies for polycystic ovary syndrome (PCOS) are accompanied by unwanted effects. Silibinin; a flavonolignan has pleiotropic activities and favorable safety profile.

Purpose

To investigate the efficacy of silibinin on estrous cyclicity, inflammation, oxidative stress and ovarian morphology in letrozole-induced PCOS in rats.

Methods

Forty-eight female Wistar albino rats were divided into 2 sets. Rats of the first set (n = 12), assigned as a negative control (NC) received only the vehicle, rats of the second set (n = 36), assigned as PCOS rats, were given letrozole 1mg/Kg orally for 21 days. On day 21, six rats from the first set and six rats from the second set were euthanized for confirmation of PCOS-induction. The remaining animals from the first set assigned as group 1, those in the second set (n = 30) were equally divided into 5 groups and treated daily for 19 days as follows: group 2 (positive control) received only the vehicle, group 3 treated with metformin 300mg/Kg orally, groups 4 and 5 treated respectively with 100 and 200 mg/Kg silibinin intraperitoneally (IP), and group 6 treated with a combination of metformin 300mg/Kg orally and silibinin 100mg/Kg IP. On day 40, blood samples were examined for luteinizing hormone (LH), testosterone (TS) and estradiol (EST) levels, the anti-inflammatory and antioxidant parameters, ovarian and uterine morphology.

Results

Silibinin alone or in combination with metformin was found to be effective in restoring the regularity of estrous cycle by ameliorating the abnormal alterations of LH, TS, EST, tumor necrosis factor (TNF)-α, and oxidative status and by resuming the appearance of corpora lutea and decreasing or even total absence of cystic follicles in the ovaries.

Conclusion

Silibinin was effective in restoring estrous regularities and alleviating hormonal and histomorphological abnormalities of the ovarian and uterine tissues, this could be due to its anti-androgenic, anti-inflammatory and antioxidant properties.

The Two-Faced Role of Autophagy in Endometrial Cancer

Autophagy, meaning “self-eating,” is a cellular catabolic process that involves lysosomal degradation of cytoplasmic materials. Autophagy contributes to both quality control and energy supply of cells, which are associated with tumorigenesis and tumor development, respectively. Endometrial cancer (EC) is the most common gynecologic cancer, and its incidence is increasing. Although autophagy plays crucial roles in several types of cancer, such as pancreatic ductal adenocarcinoma, its role in EC has not been clearly demonstrated. Activation of the PI3K/AKT/mTOR pathway, which functions to suppress autophagy, is an initial step in type 1 endometrial carcinogenesis, whereas a loss-of-function mutation of TP53, which augments autophagy via p16 induction, is the main cause of type 2 endometrial carcinogenesis. Mutations in autophagy-related genes, including ATG4C, RB1CC1/FIP200, and ULK4, have been reported in EC; thus, an aberrant autophagy mechanism may be involved in endometrial carcinogenesis. Furthermore, the biguanide diabetes drug metformin, treatment with which enhances autophagy via AMPK-mediated mTOR inactivation, has been reported to reduce the risk of EC. These findings suggest that autophagy negatively regulates endometrial carcinogenesis, and autophagy inducers may be useful for chemoprevention of EC. In contrast, autophagy appears to promote EC once it is established. Consistent with this, treatment with chloroquine, an autophagy inhibitor, is reported to attenuate EC cell proliferation. Moreover, chemotherapy-induced autophagy triggers chemoresistance in EC cells. As autophagy has a tumor-promoting function, the combination of chemotherapy and autophagy inhibitors such as chloroquine could be a potent therapeutic option for patients with EC. In conclusion, autophagy plays a dual role in the prevention and treatment of EC. Therefore, targeting autophagy to prevent and treat EC requires diametrically opposed strategies.

The Role of mTOR and eIF Signaling in Benign Endometrial Diseases

Adenomyosis, endometriosis, endometritis, and typical endometrial hyperplasia are common non-cancerous diseases of the endometrium that afflict many women with life-impacting consequences. The mammalian target of the rapamycin (mTOR) pathway interacts with estrogen signaling and is known to be dysregulated in endometrial cancer. Based on this knowledge, we attempt to investigate the role of mTOR signaling in benign endometrial diseases while focusing on how the interplay between mTOR and eukaryotic translation initiation factors (eIFs) affects their development. In fact, mTOR overactivity is apparent in adenomyosis, endometriosis, and typical endometrial hyperplasia, where it promotes endometrial cell proliferation and invasiveness. Recent data show aberrant expression of various components of the mTOR pathway in both eutopic and ectopic endometrium of patients with adenomyosis or endometriosis and in hyperplastic endometrium as well. Moreover, studies on endometritis show that derangement of mTOR signaling is linked to the establishment of endometrial dysfunction caused by chronic inflammation. This review shows that inhibition of the mTOR pathway has a promising therapeutic effect in benign endometrial conditions, concluding that mTOR signaling dysregulation plays a critical part in their pathogenesis.

Autophagy in ovary and polycystic ovary syndrome: role, dispute and future perspective

Polycystic ovary syndrome (PCOS) is a unification of endocrine and metabolic disorders and has become immensely prevalent among women of fertile age. The prime organ affected in PCOS is the ovary and its distressed functioning elicits disturbed reproductive outcomes. In the ovary, macroautophagy/autophagy performs a pivotal role in directing the chain of events starting from oocytes origin until its fertilization. Recent discoveries demonstrate a significant role of autophagy in the pathogenesis of PCOS. Defective autophagy in the follicular cells during different stages of follicles is observed in the PCOS ovary. Exploring different autophagy pathways provides a platform for predicting the possible cause of altered ovarian physiology in PCOS. In this review, we have emphasized autophagy's role in governing follicular development under normal circumstances and in PCOS, including significant abnormalities associated with PCOS such as anovulation, hyperandrogenemia, metabolic disturbances, and related abnormality. So far, few studies have linked autophagy and PCOS and propose its essential role in PCOS progression. However, detailed knowledge in this area is lacking. Here we have summarized the latest knowledge related to autophagy associated with PCOS. This review's main objective is to provide a background of autophagy in the ovary, its possible connection with PCOS and suggested a novel proposal for future studies to aid a better understanding of PCOS pathogenesis.Abbreviations: AE: androgen excess; AF: antral follicle; AKT/PKB: AKT serine/threonine kinase; AMH: anti-Mullerian hormone; AMPK: AMP-activated protein kinase; ATG: autophagy-related; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; BMP: bone morphogenetic protein; CASP3: caspase 3; CL: corpus luteum; CYP17A1/P450C17: cytochrome P450 family 17 subfamily A member 1; CYP19A1: cytochrome P450 family 19 subfamily A member 1; DHEA: dehydroepiandrosterone; EH: endometrial hyperplasia; FF: follicular fluid; FOXO: forkhead box O; FSH: follicle stimulating hormone; GC: granulosa cell; GDF: growth differentiation factor; HA: hyperandrogenemia; HMGB1: high mobility group box 1; IGF1: insulin like growth factor 1; INS: insulin; IR: insulin resistance; LHCGR/LHR: luteinizing hormone/choriogonadotropin receptor; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAPK/ERK: mitogen-activated protein kinase; MAPK8/JNK: mitogen-activated protein kinase 8; MTOR: mechanistic target of rapamycin kinase; MTORC: mechanistic target of rapamycin complex; NAFLD: nonalcoholic fatty liver disease; NFKB: nuclear factor kappa B; OLR1/LOX-1: oxidized low density lipoprotein receptor 1; oxLDL: oxidized low-density lipoproteins; PA: palmitic acid; PCOS: polycystic ovary syndrome; PF: primary follicle; PGC: primordial germ cell; PI3K: phosphoinositide 3-kinase; PMF: primordial follicle; ROS: reactive oxygen species; RP: resting pool; SIRT1: sirtuin 1; SQSTM1/p62: sequestosome 1; T2DM: type 2 diabetes mellitus; TC: theca cell; TUG1: taurine up-regulated 1.

Inflammatory cytokines as key players of apoptosis induced by environmental estrogens in the ovary

Natural and synthetic environmental estrogens (EEs), interfering with the physiological functions of the body's estrogens, are widespread and are rising much concern for their possible deleterious effects on human and animal health, in particular on reproduction. In fact, increasing evidence indicate that EEs can be responsible for a variety of disfunctions of the reproductive system especially in females such as premature ovarian insufficiency (POI). Because of their great structural diversity, the modes of action of EEs are controversial. One important way through which EEs exert their effects on reproduction is the induction of apoptosis in the ovary. In general, EEs can exert pro-and anti-apoptotic effects by agonizing or antagonizing numerous estrogen-dependent signaling pathways. In the present work, results concerning apoptotic pathways and diseases induced by representative EEs (such as zearalenone, bisphenol A and di-2-ethylhexyl phthalate), in ovaries throughout development are presented into an integrated network. By reviewing and elaborating these studies, we propose inflammatory factors, centered on the production of tumor necrosis factor (TNF), as a major cause of the induction of apoptosis by EEs in the mammalian ovary. As a consequence, potential strategies to prevent such EE effect are suggested.

The Multifaceted Role of Autophagy in Endometrium Homeostasis and Disease

Autophagy is a conserved fundamental cellular process with a primary function of catabolizing harmful or surplus cellular contents such as protein aggregates, dysfunctional/long-lived organelles, intracellular pathogens, and storage nutrients. An increasing body of evidence reveals that basal autophagy is essential for maintaining endometrial homeostasis and mediating endometrial-specific functions, including menstrual cycle, embryo implantation, and decidualization. However, perturbed levels of autophagy can lead to severe endometrial pathologies, including endometriosis, endometrial hyperplasia, endometrial cancer, adenomyosis, and leiomyoma. This review highlights the most recent findings on the activity, regulation, and function of autophagy in endometrium physiology and pathology. Understanding the mechanistic roles of autophagy in endometrium homeostasis and disease is key to developing novel therapeutic strategies for endometrium-related infertility and malignancies.

TLR4-Associated IRF-7 and NFκB Signaling Act as a Molecular Link Between Androgen and Metformin Activities and Cytokine Synthesis in the PCOS Endometrium

CONTEXT

Low-grade chronic inflammation is commonly seen in polycystic ovary syndrome (PCOS) patients with elevated levels of inflammatory cytokines in the endometrium.

OBJECTIVE

This work aimed to increase the limited understanding of the mechanisms underlying cytokine synthesis and increased endometrial inflammation in PCOS patients.

METHODS

Endometrial biopsy samples were collected from non-PCOS (n = 17) and PCOS (n = 22) patients either during the proliferative phase of the menstrual cycle or with hyperplasia. Endometrial explants were prepared from PCOS patients and underwent pharmacological manipulation in vitro. The expression and localization of toll-like receptor 2 (TLR2)/4, key elements of innate immune signal transduction and nuclear factor κB (NFκB) signaling pathways, and multiple cytokines were comprehensively evaluated by Western blotting, immunohistochemistry, and immunofluorescence in endometrial tissues.

RESULTS

We demonstrated the distribution of protein expression and localization associated with the significantly increased androgen receptor, TLR2, and TLR4-mediated activation of interferon regulatory factor-7 (IRF-7) and NFκB signaling, cytokine production, and endometrial inflammation in PCOS patients compared to non-PCOS patients with and without endometrial hyperplasia. In vitro experiments showed that 5-dihydrotestosterone (DHT) enhanced androgen receptor, TLR4, IRF-7, and p-NFκB p65 protein expression along with increased interferon α (IFNα) and IFNɣ abundance. The effects of DHT on IRF-7, p-NFκB p65, and IFN abundance were abolished by flutamide, an antiandrogen. Although 17β-estradiol (E2) decreased p-IRF-7 expression with little effect on TLR-mediated IRF7 and NFκB signaling or on cytokine protein levels, exposure to metformin alone or in combination with E2 suppressed interleukin-1 receptor-associated kinase 4 (IRAK4), p-IRF-7, IRF-7, IκB kinase α (IKKα), p-NFκB p65, IFNɣ, and tumor necrosis factor α protein expression.

CONCLUSION

Cytokine synthesis and increased endometrial inflammation in PCOS patients are coupled to androgen-induced TLR4/IRF-7/NFκB signaling, which is inhibited by metformin treatment.

Ameliorative Effects of Quercetin and Metformin and Their Combination Against Experimental Endometriosis in Rats

Endometriosis, as the leading cause of infertility, is attributed to oxidative stress, inflammation, and autophagy dysregulation. This study was conducted to evaluate the effect of quercetin and metformin, alone or in combination, on the ectopic and eutopic endometrial tissues in a rat model of endometriosis. We divided 60 female rats into 6 groups, including SH, Endo, Endo + Oil, Endo + Q, Endo + M, and Endo + Q + M. The last five groups underwent a surgery, so that we could induce endometriosis, and after 4 weeks, daily treatment began, lasting for a month. Subsequently, the size and histoarchitecture of the endometrial implants, serum levels of 17β-estradiol, progesterone and tumor necrosis factor (TNF)-α, and markers of oxidative stress and autophagy were assessed utilizing ELISA and gene expression analysis. Our results shed light to the fact that serum TNF-α and 17β-estradiol levels significantly increased in endometriosis rats. Moreover, NADPH: quinone oxidoreductase (NQO1) enzyme activity and gene expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and autophagy markers significantly decreased; meanwhile, mammalian target of rapamycin (mTOR) gene expression increased in the ectopic endometrial tissues, as compared with eutopic ones. Surprisingly, our results demonstrated that the treatment in which we applied the combination of quercetin and metformin significantly reversed these changes and had a pronounced effect on the endometrial implant size and gene expression levels of mTOR and autophagy markers in ectopic endometrium. The findings of the present study suggest that quercetin, metformin, and their combination were of potential therapeutic effects on the rat model of endometriosis.

The effects of metformin on autophagy

Metformin is the first-line option for treating newly diagnosed diabetic patients and also involved in other pharmacological actions, including antitumor effect, anti-aging effect, polycystic ovarian syndrome prevention, cardiovascular action, and neuroprotective effect, etc. However, the mechanisms of metformin actions were not fully illuminated. Recently, increasing researches showed that autophagy is a vital medium of metformin playing pharmacological actions. Nevertheless, results on the effects of metformin on autophagy were inconsistent. Apart from few clinical evidences, more data focused on kinds of no-clinical models. First, many studies showed that metformin could induce autophagy via a number of signaling pathways, including AMPK-related signaling pathways (e.g. AMPK/mTOR, AMPK/CEBPD, MiTF/TFE, AMPK/ULK1, and AMPK/miR-221), Redd1/mTOR, STAT, SIRT, Na⁺/H⁺ exchangers, MAPK/ERK, PK2/PKR/AKT/ GSK3β, and TRIB3. Secondly, some signaling pathways were involved in the process of metformin inhibiting autophagy, such as AMPK-related signaling pathways (AMPK/NF-κB and other undetermined AMPK-related signaling pathways), Hedgehog, miR-570-3p, miR-142-3p, and MiR-3127-5p. Thirdly, two types of signaling pathways including PI3K/AKT/mTOR and endoplasmic reticulum (ER) stress could bidirectionally impact the effectiveness of metformin on autophagy. Finally, multiple signal pathways were reviewed collectively in terms of affecting the effectiveness of metformin on autophagy. The pharmacological effects of metformin combining its actions on autophagy were also discussed. It would help better apply metformin to treat diseases in term of mediating autophagy.

Ovarian hormones-autophagy-immunity axis in menstruation and endometriosis

Menstruation occurs in few species and involves a cyclic process of proliferation, breakdown and regeneration under the control of ovarian hormones. Knowledge of normal endometrial physiology, as it pertains to the regulation of menstruation, is essential to understand disorders of menstruation. Accumulating evidence indicates that autophagy in the endometrium, under the regulation of ovarian hormones, can result in the infiltration of immune cells, which plays an indispensable role in the endometrium shedding, tissue repair and prevention of infections during menstruation. In addition, abnormal autophagy levels, together with resulting dysregulated immune system function, are associated with the pathogenesis and progression of endometriosis. Considering its potential value of autophagy as a target for the treatment of menstrual-related and endometrium-related disorders, we review the activity and function of autophagy during menstrual cycles. The role of the estrogen/progesterone-autophagy-immunity axis in endometriosis are also discussed.

Melatonin ameliorates excessive PINK1/Parkin-mediated mitophagy by enhancing SIRT1 expression in granulosa cells of PCOS

Mitochondrial injury in granulosa cells is associated with the pathogenesis of polycystic ovary syndrome (PCOS). However, the protective effects of melatonin against mitochondrial injury in the granulosa cells of PCOS remain unclear. In this study, decreased mitochondrial membrane potential and mtDNA content, increased number of autophagosomes were found in the granulosa cells of PCOS patients and the dihydrotestosterone (DHT)-treated KGN cells, with decreased protein level of the autophagy substrate p62 and increased levels of the cellular autophagy markers Beclin 1 and LC3B-II, while the protein levels of PTEN-induced kinase-1 (PINK1) and Parkin were increased and the level of sirtuin 1 (SIRT1) was decreased. DHT-induced PCOS-like mice also showed enhanced mitophagy and decreased SIRT1 mRNA expression. Melatonin treatment significantly increased the protein level of SIRT1 and decreased the levels of PINK1/Parkin, whereas it ameliorated the mitochondrial dysfunction and PCOS phenotype in vitro and in vivo. However, when the KGN cells were treated with SIRT1 siRNA to knock down SIRT1 expression, melatonin treatment failed to repress the excessive mitophagy. In conclusion, melatonin protects against mitochondrial injury in granulosa cells of PCOS by enhancing SIRT1 expression to inhibit excessive PINK1/Parkin-mediated mitophagy.

Pharmacokinetic Interaction between Sorafenib and Atorvastatin, and Sorafenib and Metformin in Rats

The tyrosine kinase inhibitor sorafenib is the first-line treatment for patients with hepatocellular carcinoma (HCC), in which hyperlipidemia and type 2 diabetes mellitus (T2DM) may often coexist. Protein transporters like organic cation (OCT) and multidrug and toxin extrusion (MATE) are involved in the response to sorafenib, as well as in that to the anti-diabetic drug metformin or atorvastatin, used in hyperlipidemia. Changes in the activity of these transporters may lead to pharmacokinetic interactions, which are of clinical significance. The study aimed to assess the sorafenib−metformin and sorafenib−atorvastatin interactions in rats. The rats were divided into five groups (eight animals in each) that received sorafenib and atorvastatin (I_SOR+AT), sorafenib and metformin (II_SOR+MET), sorafenib (III_SOR), atorvastatin (IV_AT), and metformin (V_MET). Atorvastatin significantly increased the maximum plasma concentration (C_max) and the area under the plasma concentration–time curve (AUC) of sorafenib by 134.4% (p < 0.0001) and 66.6% (p < 0.0001), respectively. Sorafenib, in turn, caused a significant increase in the AUC of atorvastatin by 94.0% (p = 0.0038) and its metabolites 2−hydroxy atorvastatin (p = 0.0239) and 4−hydroxy atorvastatin (p = 0.0002) by 55.3% and 209.4%, respectively. Metformin significantly decreased the AUC of sorafenib (p = 0.0065). The AUC ratio (II_SOR+MET group/III_SOR group) for sorafenib was equal to 0.6. Sorafenib did not statistically significantly influence the exposure to metformin. The pharmacokinetic interactions observed in this study may be of clinical relevance in HCC patients with coexistent hyperlipidemia or T2DM.

Combination of aloin and metformin enhances the antitumor effect by inhibiting the growth and invasion and inducing apoptosis and autophagy in hepatocellular carcinoma through PI3K/AKT/mTOR pathway

Hepatocellular carcinoma (HCC) is a devastating and highly metastatic cancer worldwide. Metformin (MET) is the priority drug for treatment of type 2 diabetes; however, it possesses multiple biological effects like anticancer and hepatoprotective activity. Herein, we examined the effects of aloin (barbaloin) and MET as well as combination treatment in HCC cell line in vitro and in vivo. As a result, aloin and MET alone exhibited inhibitory effects on proliferation and invasion of HepG2 and Bel-7402 cells. Specially, combination treatment of aloin and MET showed enhanced inhibitory effects in vitro. Aloin and MET alone induced apoptosis and autophagy in vitro. Similarly, aloin and MET cooperated to promote apoptosis and autophagy in HepG2 and Bel-7402 cells. In the HepG2 xenograft models, aloin in combination with MET confine tumor growth and facilitate apoptosis and autophagy. Both the in vitro and in vivo results showed that aloin and MET alone as well as combination treatment activated the PI3K/AKT/mTOR pathway. Overall, our research demonstrated that the concomitant treatment with aloin and MET enhances the antitumor effect by inhibiting the growth and invasion as well as inducing apoptosis and autophagy in HCC through PI3K/AKT/mTOR pathway.