Abnormal HCK/glutamine/autophagy axis promotes endometriosis development by impairing macrophage phagocytosis

The presence of extensive infiltrated macrophages with impaired phagocytosis is widely recognised as a significant regulator for the development of endometriosis (EMs). Nevertheless, the metabolic characteristics and the fundamental mechanism of impaired macrophage phagocytosis are yet to be clarified. Here, we observe that there is the decreased expression of haematopoietic cellular kinase (HCK) in macrophage of peritoneal fluid from EMs patients, which might be attributed to high oestrogen and hypoxia condition. Of note, HCK deficiency resulted in impaired macrophage phagocytosis, and increased number and weight of ectopic lesions in vitro and in vivo. Mechanistically, this process was mediated via regulation of glutamine metabolism, and further upregulation of macrophage autophagy in a c-FOS/c-JUN dependent manner. Additionally, macrophages of EMs patients displayed insufficient HCK, excessive autophagy and phagocytosis dysfunction. In therapeutic studies, supplementation with glutamine-pre-treated macrophage or Bafilomycin A1 (an autophagy inhibitor)-pre-treated macrophage leads to the induction of macrophage phagocytosis and suppression of EMs development. This observation reveals that the aberrant HCK-glutamine-autophagy axis results in phagocytosis obstacle of macrophage and further increase the development risk of Ems. Additionally, it offers potential therapeutic approaches to prevent EMs, especially patients with insufficient HCK and macrophage phagocytosis dysfunction.

The "Road" to Malignant Transformation from Endometriosis to Endometriosis-Associated Ovarian Cancers (EAOCs): An mTOR-Centred Review

Ovarian cancer is an umbrella term covering a number of distinct subtypes. Endometrioid and clear-cell ovarian carcinoma are endometriosis-associated ovarian cancers (EAOCs) frequently arising from ectopic endometrium in the ovary. The mechanistic target of rapamycin (mTOR) is a crucial regulator of cellular homeostasis and is dysregulated in both endometriosis and endometriosis-associated ovarian cancer, potentially favouring carcinogenesis across a spectrum from benign disease with cancer-like characteristics, through an atypical phase, to frank malignancy. In this review, we focus on mTOR dysregulation in endometriosis and EAOCs, investigating cancer driver gene mutations and their potential interaction with the mTOR pathway. Additionally, we explore the complex pathogenesis of transformation, considering environmental, hormonal, and epigenetic factors. We then discuss postmenopausal endometriosis pathogenesis and propensity for malignant transformation. Finally, we summarize the current advancements in mTOR-targeted therapeutics for endometriosis and EAOCs.

Transcription factor EB-mediated autophagy affects cell migration and inhibits apoptosis to promote endometriosis

Autophagy has emerged as an important process of cell metabolism. With continuous in-depth research on autophagy, TFEB has been a key transcription factor regulating autophagy levels in recent years. Studies have established that TFEB regulates autophagy and apoptosis in various diseases. However, the relationship between TFEB and the pathogenesis of endometriosis remains unclear. This study aimed to investigate the effect of TFEB on the mechanism of endometriosis progression. The results showed that TFEB and autophagy-related protein LC3 are highly expressed in ectopic endometrium of patients with endometriosis, overexpression of TFEB in cultured human endometrial stromal cells (HESCs) by lentivirus not only promoted autophagy but also inhibited apoptosis. In addition, the migration and invasion ability of HESCs were enhanced by TFEB overexpression. Furthermore, inhibiting autophagy with specific inhibitors can attenuate migration and invasion of HESCs induced by TFEB. The rat models of endometriosis show that TFEB knockdown can suppress lesion growth in vivo. Our results suggest that autophagy may be involved in the progression mechanism of endometriosis, and the mechanism of autophagy disorder in endometriosis is probably related to TFEB. TFEB may be a key molecule in promoting endometriosis.

The mysterious association between adiponectin and endometriosis

Adiponectin is a pleiotropic cytokine predominantly derived from adipose tissue. In addition to its role in regulating energy metabolism, adiponectin may also be related to estrogen-dependent diseases, and many studies have confirmed its involvement in mediating diverse biological processes, including apoptosis, autophagy, inflammation, angiogenesis, and fibrosis, all of which are related to the pathogenesis of endometriosis. Although many researchers have reported low levels of adiponectin in patients with endometriosis and suggested that it may serve as a protective factor against the development of the disease. Therefore, the purpose of this review was to provide an up-to-date summary of the roles of adiponectin and its downstream cytokines and signaling pathways in the aforementioned biological processes. Further systematic studies on the molecular and cellular mechanisms of action of adiponectin may provide novel insights into the pathophysiology of endometriosis as well as potential therapeutic targets.

The autophagy protein, ATG14 safeguards against unscheduled pyroptosis activation to enable embryo transport during early pregnancy

Recurrent pregnancy loss (RPL), characterized by two or more failed clinical pregnancies, poses a significant challenge to reproductive health. In addition to embryo quality and endometrial function, proper oviduct function is also essential for successful pregnancy establishment. Therefore, structural abnormalities or inflammation resulting from infection in the oviduct may impede the transport of embryos to the endometrium, thereby increasing the risk of miscarriage. However, the precise cellular mechanisms that maintain the structural and functional integrity of the oviduct are not studied yet. Here, we report that autophagy is critical for maintaining the oviduct homeostasis and keeping the inflammation under check to enable embryo transport. Specifically, the loss of the autophagy-related gene, Atg14 in the oviduct causes severe structural abnormalities compromising its cellular plasticity and integrity leading to the retention of embryos. Interestingly, the selective loss of Atg14 in oviduct ciliary epithelial cells did not impact female fertility, highlighting the specificity of ATG14 function in distinct cell types within the oviduct. Mechanistically, loss of Atg14 triggered unscheduled pyroptosis leading to inappropriate embryo retention and impeded embryo transport in the oviduct. Finally, pharmacological activation of pyroptosis in pregnant mice led to an impairment in embryo transport. Together, we found that ATG14 safeguards against unscheduled pyroptosis activation to enable embryo transport from the oviduct to uterus for the successful implantation. Of clinical significance, these findings provide possible insights on the underlying mechanism(s) of early pregnancy loss and might aid in developing novel prevention strategies using autophagy modulators.

CircFOXO3 mediates hypoxia-induced autophagy of endometrial stromal cells in endometriosis

Endometriosis is a benign gynecological disease that shares some common features of malignancy. Autophagy plays vital roles in endometriosis and influences endometrial cell metastasis, and hypoxia was identified as the initiator of this pathological process through hypoxia inducible factor 1 alpha (HIF-1α). A newly discovered circular RNA FOXO3 (circFOXO3) is critical in cell autophagy, migration, and invasion of various diseases and is reported to be related to hypoxia, although its role in endometriosis remains to be elucidated up to now. In this study, a lower circFOXO3 expression in ectopic endometrium was investigated. Furthermore, we verified that circFOXO3 could regulate autophagy by downregulating the level of p53 protein to mediate the migration and invasion of human endometrial stromal cells (T HESCs). Additionally, the effects of HIF-1α on circFOXO3 and autophagy were examined in T HESCs. Notably, overexpression of HIF-1α could induce autophagy and inhibit circFOXO3 expression, whereas overexpressing of circFOXO3 under hypoxia significantly inhibited hypoxia-induced autophagy. Mechanistically, the direct combination between HIF-1α and HIF-1α-binding site on adenosine deaminase 1 acting on RNA (ADAR1) promoter increased the level of ADAR1 protein, which bind directly with circFOXO3 pre-mRNA to block the cyclization of circFOXO3. All these results support that hypoxia-mediated ADAR1 elevation inhibited the expression of circFOXO3, and then autophagy was induced upon loss of circFOXO3 via inhibition of p53 degradation, participating in the development of endometriosis.

Dienogest attenuates STAT3 activation in ovarian endometriotic cysts

OBJECTIVE

Recent studies have suggested that endometriosis could be the result of excessive activation of signal transducer and activator of transcription 3 (STAT3), which is associated with the regulation of essential cellular mechanisms such as proliferation, invasion, and apoptosis. That finding implies that regulating STAT3 activation could play a key role in treating endometriosis. In the present study, we aimed to evaluate whether the anti-endometriotic effects of dienogest is mediated by the regulation of STAT3 activation.

STUDY DESIGN

STAT3 activation was evaluated in normal endometrial and ovarian endometriotic tissues obtained from patients with/without preoperative dienogest treatment. A subsequent in vitro analysis with endometriotic cyst stromal cells (ECSCs) was used to confirm the direct influence of dienogest in STAT3 activation.

RESULT

STAT3 activation is significantly higher in endometriotic tissues from non-treated patients than in normal endometrial tissues, and that difference is reversed by preoperative administration of dienogest. Similarly, the inhibitory effects of dienogest on STAT3 activation are demonstrated by in vitro results showing that dienogest treatment significantly inhibits IL-6-stimulated STAT3 activation in cultured ECSCs. That inhibition was accompanied by decreased expression of proliferative (PCNA), invasive (MMP-2), and anti-apoptotic (BCL-2) proteins. Furthermore, downregulating STAT3 activity with siRNA decreased PCNA, MMP-2, and BCL-2 expression in IL-6-treated ECSCs.

CONCLUSION

Dienogest inhibits STAT3 activation in ECSCs, which affects their proliferation, invasiveness, and apoptosis.

Endometriosis and adenomyosis: Similarities and differences

Deep endometriosis and uterine adenomyosis are two frequently encountered conditions affecting approximately 200 million women worldwide. They are closely related, showing similar histological patterns and multiple common pathogenic features, and share the same symptoms. It is therefore not surprising that they are often thought to have a common developmental origin. Indeed, both deep endometriosis and adenomyosis appear to derive from estrogen-dependent overproliferation of endometrial tissue and its subsequent implantation in ectopic sites. Although the scientific community has shown increasing interest in these diseases over recent years, neither pathogenesis has yet been elucidated, so there are currently no efficient treatment options. Understanding the mechanisms underlying disease development, as well as discerning their relationship, are key to improving clinical management for millions of patients. The aims of this review are to summarize current knowledge on deep endometriosis and adenomyosis pathogeneses and discuss the possibility that these two entities are actually differential phenotypes of the same disease.

Molecular mechanism of autophagy and apoptosis in endometriosis: Current understanding and future research directions

Background

Endometriosis is a common gynecological condition, with symptoms including pain and infertility. Regurgitated endometrial cells into the peritoneal cavity encounter hypoxia and nutrient starvation. Endometriotic cells have evolved various adaptive mechanisms to survive in this inevitable condition. These adaptations include escape from apoptosis. Autophagy, a self-degradation system, controls apoptosis during stress conditions. However, to date, the mechanisms regulating the interplay between autophagy and apoptosis are still poorly understood. In this review, we summarize the current understanding of the molecular characteristics of autophagy in endometriosis and discuss future therapeutic challenges.

Methods

A search of PubMed and Google Scholar databases were used to identify relevant studies for this narrative literature review.

Results

Autophagy may be dynamically regulated through various intrinsic (e.g., PI3K/AKT/mTOR signal transduction network) and extrinsic (e.g., hypoxia and iron-mediated oxidative stress) pathways, contributing to the development and progression of endometriosis. Upregulation of mTOR expression suppresses apoptosis via inhibiting the autophagy pathway, whereas hypoxia or excess iron often inhibits apoptosis via promoting autophagy.

Conclusion

Endometriotic cells may have acquired antiapoptotic mechanisms through unique intrinsic and extrinsic autophagy pathways to survive in changing environments.

Autophagy-dependent ferroptosis is involved in the development of endometriosis

OBJECTIVE

Endometriosis (EMS) is an estrogen-dependent condition with unclear pathogenesis. Recent findings suggest implicate autophagy and ferroptosis in EMS development.

METHODS

We assessed autophagy and ferroptosis proteins in EMS patients using immunohistochemistry and western blot and established an EMS rat model through allograft endometrial transplantation, confirmed via hematoxylin and eosin staining and epithelial-mesenchymal transition -related proteins. Primary EMS cells were isolated from the model rats and cultured under five conditions: control, EMS, EMS with Rapamycin (autophagy inducer), EMS with si-Atg5 (autophagy inhibitor), and EMS with si-Atg5 plus Erastin (ferroptosis inducer). We evaluated cell viability, iron content, oxidative stress, and mitochondrial morphologyin EMS cells, and detected autophagy and ferroptosis proteins through immunofluorescence, western blot, and monodansylcadaverine staining.

RESULTS

Autophagy proteins Beclin1 and LC3 were highly expressed, whereas p62, glutathione peroxidase 4, and p53 were lowly expressed in EMS patients. Rapamycin decreased cell viability but increased iron content, reactive oxygen species, lipid peroxide production, the number of ferroptotic mitochondria, and the expression of autophagy proteins in EMS cells, while si-Atg5 showed opposite effects. Additionally, Erastin reversed the impact of si-Atg5 on EMS cells.

CONCLUSION

Our findings suggest that autophagy-dependent ferroptosis plays a role in EMS progression.

Recent insights explaining susceptibility to endometriosis-From genetics to environment

Endometriosis is a disease with a heterogeneous pathogenesis, explained by multiple theories, and also with a polymorphic presentation. The purpose of this literature review is to systematize the genetic, inflammatory, and environmental factors related to the pathophysiology of endometriosis. Current evidence suggests that endometriosis is a complex inherited genetic condition, in which the genes that determine susceptibility to the disease interact with the environment to develop different phenotypes. Genetic variants associated with risk of endometriosis have been identified in several genome-wide association studies, in addition to a group of genes related to the pathophysiology of endometriosis, namely the estrogen, progesterone and androgen receptors and the cytochrome P450 gene, as well as the p53 gene. The role of inflammation is controversial; however, it is an essential process, both in the initiation and perpetuation of the disease, in and outside the pelvis. Alterations in reactive oxygen species pathways that consequently determine oxidative stress are typical in the inflammatory environment of endometriosis. The role of environmental factors is a relatively new and broad-spectrum topic, with inconsistent evidence. Multiple factors have been studied such as endocrine-disrupting chemicals, metals, intrauterine exposure to diethylstilbesterol and lifestyle risk factors. In conclusion, endometriosis remains a mysterious condition, with multifactorial factors involved in its pathophysiology. The progress that has been made in the genetic predisposition to endometriosis may allow the establishment of new therapeutic targets. On the other hand, understanding the role of the environment in this disease may allow preventive intervention, minimizing its incidence and/or severity. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors Reproductive System Diseases > Genetics/Genomics/Epigenetics.

DIRAS3 regulates autophagy in an endometriosis epithelial cell line

RESEARCH QUESTION

What is the role of DIRAS3 in endometriosis pathogenesis?

DESIGN

Prospective patient cohort study combined with experiments in the 12Z human endometriosis epithelial cell line model to determine the role of DIRAS3 in endometriosis. Endometrium and endometriosis lesion samples were collected from premenopausal women from 24 control and 40 endometriosis patients by laparoscopic surgery. The role of DIRAS3 in endometriosis was assessed by siRNA knockdown in 12Z cells followed by proliferation, apoptosis, invasion and autophagy assays. Autophagy was induced by serum starvation and the levels of autophagy determined by assessing changes in the expression levels and localization of autophagy marker proteins, such as LC3.

RESULTS

DIRAS3 mRNA showed a large increase in expression in ectopic endometriosis lesions compared with endometrium from control patients, with expression largely localized to the epithelium. DIRAS3 knockdown in 12Z endometriosis epithelial cells caused a significant reduction in the number of proliferating cells (1.6-fold, adjusted P = 0.0007) and increased apoptosis (AnnexinV/7AAD double-positive cells +48%, P = 0.01), indicating an effect on cell proliferation. Induction of autophagy by serum starvation caused significant upregulation in DIRAS3 expression after 24 h (mRNA +2.4-fold [adjusted P = 0.017], protein +8.1-fold (adjusted P = 0.029), reduced LC3I/LC3II ratio (-2.2-fold, adjusted P = 0.044) and an increase in the number of double positive LC3/DIRAS3 puncta (+2.3-fold, P = 0.02). Knockdown of DIRAS3 in serum-starved cells led to a reduction in autophagy, indicated by an overall decrease in LC3 expression and significant increase in LC3I/LC3II ratio.

CONCLUSIONS

DIRAS3 is highly upregulated in endometriosis lesions. Studies in an endometriosis epithelial cell line indicate that DIRAS3 facilitates cell survival in this context by inducing autophagy.

Are lower levels of apoptosis and autophagy behind adenomyotic lesion survival?

RESEARCH QUESTION

How are markers of cell death, invasiveness and progesterone signalling expressed in endometrium and ectopic lesions from adenomyosis patients?

DESIGN

Formalin-fixed paraffin-embedded tissue was collected from 15 control and 15 adenomyosis participants . To assess cell survival capacity, caspase 3 and microtubule-associated proteins 1A/1B light chain 3B (LC3B) were immunolabelled as markers of apoptosis and autophagy respectively. Matrix metalloproteinase 9 (MMP9) expression served as a marker of extracellular matrix degradation and invasion activity. Progesterone receptors were immunostained to detect evidence of progesterone resistance.

RESULTS

Caspase 3 expression was significantly lower in the stromal (P = 0.0013) and epithelial (P = 0.0157) compartments of adenomyotic lesions than in healthy endometrial tissue. In the stroma, caspase 3 expression was significantly weaker in lesions than in corresponding eutopic endometrium (P = 0.0006). LC3B immunostaining was significantly decreased in adenomyotic stroma compared with corresponding eutopic endometrium (P = 0.0349). A significantly higher expression of MMP9 was detected in eutopic stroma from adenomyosis patients than in healthy tissue (P = 0.0295). Progesterone receptor immunostaining was found to be significantly weaker in the stroma of endometrium and ectopic lesions from adenomyosis patients than disease-free women (P = 0.0001; P = 0.0021).

CONCLUSIONS

Adenomyotic lesions show lower levels of apoptosis and autophagy, suggesting that aberrant cell survival may be involved in disease pathogenesis. MMP9 appears to contribute to endometrial invasiveness in adenomyosis, as its expression is more pronounced in endometrium from these women than women without the disease. Evidence of progesterone resistance can be found in endometrium and ectopic lesions from adenomyosis patients, and may drive disease development and account for the failure of certain patients to respond to progestogens.

Endometriosis-Associated Ovarian Carcinomas: How PI3K/AKT/mTOR Pathway Affects Their Pathogenesis

Ovarian clear cell (OCCC) and endometrioid (EnOC) carcinomas are often subsumed under the umbrella term "endometriosis-associated ovarian cancer" (EAOC), since they frequently arise from ectopic endometrium settled in the ovaries. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is known to be aberrantly activated both in endometriosis and EAOC; however, its role in the progression of endometriosis to ovarian cancer remains unclear. In fact, cancer-associated alterations in the mTOR pathway may be found in normal uterine epithelium, likely acting as a first step towards ovarian cancer, through the intermediary stage of endometriosis. This review aims to summarize the current knowledge regarding mTOR signaling dysregulation in the uterine endometrium, endometriosis, and EAOC while focusing on the interconnections between the PI3K/AKT/mTOR pathway and other signaling molecules that give rise to synergistic molecular mechanisms triggering ovarian cancer development in the presence of endometriosis.

The role of endoplasmic reticulum stress in endometriosis

Endometriosis is a chronic gynecologic disorder characterized by abnormal growth of endometrium-like tissues in the ectopic regions of the pelvic peritoneum. The pathophysiology of endometriosis is not completely understood; however, excessive endometrial cell proliferation together with resistance to apoptosis facilitates the migration, implantation, and survival of endometrial cells in the distant sites. Endoplasmic reticulum (ER) stress response (also called unfolded protein response) is a cellular defense mechanism triggered by ER stress. When severe enough, the so-called response initiates cell suicide, i.e., apoptosis. Therefore, therapeutic induction of ER stress in endometriotic cells could promote apoptosis and contribute to the management of disease. In this review, we discuss the pathogenic role of ER stress in endometriosis and the most recent findings regarding the induction of ER stress in connection with endometriosis.

Complex Interplay between Autophagy and Oxidative Stress in the Development of Endometriosis

Endometriosis (Endo) is a chronic gynecological disease. This paper aimed to evaluate the modulation of autophagy, oxidative stress and apoptosis with Açai Berries in a rat model of endometriosis. Endometriosis was induced with an intraperitoneal injection of minced uterus tissue from a donor rat into a recipient one. The abdominal high-frequency ultrasound (hfUS) analysis was performed at 7 and 14 days from the endometriosis induction to evaluate the growth of the lesion during the experiment. Seven days from the induction, once the lesions were implanted, an Açai Berry was administered daily by gavage for the next seven days. At the end of the experiment, the hfUS analysis showed a reduced lesion diameter in animals given the Açai Berry. A macroscopical and histological analysis confirmed this result. From the molecular point of view, Western blot analyses were conducted to evaluate the autophagy induction. Samples collected from the Endo group showed impaired autophagy, while the Açai Berry administration inhibited PI3K and AKT and ERK1/2 phosphorylation and promoted autophagy by inactivating mTOR. Additionally, Açai Berry administration dephosphorylated ATG1, promoting the activity of the ATG1/ULK1 complex that recruited Ambra1/Beclin1 and Atg9 to promote autophagosome nucleation and LC3II expression. Açai Berry administration also restored mitophagy, which increased Parkin cytosolic expression. The Açai Berry increased the expression of NRF2 in the nucleus and the expression of its downstream antioxidant proteins as NQO-1 and HO-1, thereby restoring the oxidative imbalance. It also restored the impaired apoptotic pathway by reducing BCL-2 and increasing BAX expression. This result was also confirmed by the TUNEL assay. Overall, our results displayed that Açai Berry administration was able to modulate autophagy, oxidative stress and apoptosis during endometriosis.

Decreased Krüppel-like factor 4 in adenomyosis impairs decidualization by repressing autophagy in human endometrial stromal cells

Background

Poor decidualization and abnormal autophagy conditions in the endometria of adenomyosis patients have been reported previously. However, the specific regulatory mechanism of decidualization in adenomyosis and its relationship with autophagy levels have not been clarified.

Methods

Endometrial tissues from adenomyosis patients and uteri from an adenomyosis mouse model were collected for the detection of different expression patterns of KLF4 and autophagy markers (LC3-B/LC3-A and Beclin-1) compared with control groups. Human endometrial stromal cells (hESCs) isolated from adenomyosis and control endometrial tissues were employed to elucidate the biological functions of KLF4 in autophagy and decidualization. Gene expression regulation was examined by quantitative real-time PCR (qRT-PCR), western blotting and luciferase reporter assays. In addition, DNA promoter-protein interactions were examined by chromatin immunoprecipitation (ChIP)/PCR assay and avidin–biotin conjugate DNA precipitation (ABCD) assay.

Results

KLF4 expression was decreased in endometrial tissues from adenomyosis patients compared with those from fertile controls, especially in stromal compartments. The opposite results were observed for autophagy marker (LC3-B/LC3-A and Beclin-1) expression. At the same time, KLF4 reversed the poor decidualization of hESCs from adenomyosis patients. In addition, KLF4 could induce hESC decidualization by promoting the autophagy level. Mechanistically, KLF4 bound to a conserved site in the autophagy-related 5 (ATG5) promoter region and promoted ATG5 expression. Similar expression patterns of KLF4 and autophagy markers were detected in adenomyotic mice.

Conclusions

KLF4 overexpression increases the autophagy level of hESCs by transcriptionally promoting ATG5 expression, and abnormally decreased KLF4 in adenomyosis impairs hESC decidualization by repressing autophagy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-022-00425-6.

Role of AMPK/mTOR, mitochondria, and ROS in the pathogenesis of endometriosis

Endometriosis is the presence of endometrial tissue outside the uterine cavity usually in the ovaries, fallopian tube, and pelvic cavity. It's a chronic enigmatic gynecological condition associated with dysmenorrhea, dyspareunia, pelvic pain, and infertility. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, and oxidative stress. This environment promotes cell survival through the binding of membrane receptors and subsequent cascading activation of intracellular kinases that stimulate a cellular response. In endometriosis, well-established signaling pathways, mTOR and AMPK, are altered via steroid hormones and other factors to promote cell growth, migration, and proliferation. This is accompanied by dysfunction in the mitochondria that increase energy production to sustain proliferation demands consequently leading to reactive oxygen species overproduction. This review aims to summarize the role of altered mTOR/AMPK signaling pathway, mitochondrial dysfunction, and reactive oxygen species overproduction along with providing therapeutic and diagnostic approaches. Highlighting these factors would provide a better understanding to reach a coherent theory for the pathogenesis of endometriosis.

Inhibition of the NLRP3 inflammasome by progesterone is attenuated by abnormal autophagy induction in endometriotic cyst stromal cells: implications for endometriosis

The NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is a cytosolic multi-protein complex that induces inflammation and is known to be regulated negatively by autophagy. Previous studies reported an abnormal induction of autophagy linked to progesterone resistance in human endometriotic cells. Therefore, an aberrant autophagy induction response to progesterone might contribute to the altered inflammatory response observed in endometriotic tissues. To evaluate this hypothesis, we elucidate whether regulation of the NLRP3 inflammasome by ovarian steroids is mediated by autophagy in human endometrial stromal cells (NESCs) from patients with uterine leiomyoma (presumed normal) and whether abnormal autophagy induction in endometriotic cyst stromal cells (ECSCs) affects NLRP3 inflammasome-induced interleukin-1β (IL-1β) production. Our results show that estrogen enhanced NLRP3 inflammasome activation in NESCs, resulting in increased IL-1β production. Progesterone decreased NLRP3 inflammasome activity with an increase in autophagy induction in estrogen-treated NESCs. Inhibition of NLRP3 inflammasome activity by progesterone was blocked by autophagy inhibition. However, progesterone failed to change NLRP3 inflammasome activity and autophagy induction in estrogen-treated ECSCs. By contrast, dienogest, a specific progesterone receptor agonist, reduced NLRP3 inflammasome-mediated IL-1β production through autophagy induction in ECSCs. Furthermore, autophagy induction was decreased and NLRP3 inflammasome activity was increased in endometriotic tissues, which was reversed by pre-operative administration of dienogest. In conclusion, our results suggest that progesterone inhibits NLRP3 inflammasome activation through autophagy in endometrial stromal cells. However, this inhibitory effect is attenuated in endometriotic stromal cells due to an aberrant autophagic response to progesterone, which could lead to an altered inflammatory response in endometriosis.

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.

SCM-198 Prevents Endometriosis by Reversing Low Autophagy of Endometrial Stromal Cell via Balancing ERα and PR Signals

BACKGROUND

Endometriosis (EMS), an endocrine-related inflammatory disease, is characterized by estrogen and progesterone imbalance in ectopic lesions. However, its pathogenic mechanism has not been fully elucidated. While SCM-198 is the synthetic form of leonurine and has multiple pharmacological activities such as antioxidation and anti-inflammation, it remains unknown whether it could inhibit the progress of EMS by regulating estrogen signaling and inflammation.

METHODS

The therapeutic effects of SCM-198 on EMS and its potential mechanism were analyzed by establishing EMS mouse models and performing an RNA sequencing (RNA-seq) assay. ELISA was performed to detect estrogen and tumor necrosis factor (TNF) -α concentrations in normal endometrial stromal cells (nESCs) and ectopic endometrial stromal cells (eESCs) with or without SCM-198 treatment. Western blotting, RNA silencing, and plasmid overexpression were used to analyze the relationship between inflammation, endocrine factors, and autophagy and the regulatory activity of SCM-198 on the inflammation-endocrine-autophagy axis.

RESULTS

Increased estrogen-estrogen receptor (ER) α signaling and decreased progesterone receptor isoform B (PRB) expression synergistically led to a hypo-autophagy state in eESCs, which further inhibited the apoptosis of eESCs. The high expression of TNF-α in eESCs enhanced the antiapoptotic effect mediated by low autophagy through the activation of the aromatase-estrogen-ERα signaling pathway. SCM-198 inhibited the growth of ectopic lesions in EMS mice and promoted the apoptosis of eESCs both in vivo and in vitro. The apoptotic effect of SCM-198 on eESCs was attained by upregulating the autophagy level via the inhibition of the TNF-α-activated aromatase-estrogen-ERα signal and the increase in PRB expression.

CONCLUSION

Inflammation facilitated the progress of EMS by disrupting the estrogen regulatory axis. SCM-198 inhibited EMS progression by regulating the inflammation-endocrine-autophagy axis.

Polycystic ovary syndrome: Identification of novel and hub biomarkers in the autophagy-associated mRNA-miRNA-lncRNA network

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common metabolic and endocrine disorder prevalent among women of reproductive age. Recent studies show that autophagy participated in the pathogenesis of PCOS, including anovulation, hyperandrogenism, and metabolic disturbances. This study was designed to screen autophagy-related genes (ATGs) that may play a pivotal role in PCOS, providing potential biomarkers and identifying new molecular subgroups for therapeutic intervention.

METHODS

Gene expression profiles of the PCOS and control samples were obtained from the publicly available Gene Expression Omnibus database. The gene lists of ATGs from databases were integrated. Then, the weighted gene co-expression network analysis was conducted to obtain functional modules and construct a multifactorial co-expression network. Gene Ontology and KEGG pathway enrichment analyses were performed for further exploration of ATG's function in the key modules. Differentially expressed ATGs were identified and validated in external datasets with the Limma R package. To provide guidance on PCOS phenotyping, the dysfunction module consists of a co-expression network mapped to PCOS patients. A PCOS-Autophagy-related co-expression network was established using Cytoscape, followed by identifying molecular subgroups using the Limma R package. ps. RNA-sequencing analysis was used to confirm the differential expression of hub ATGs, and the diagnostic value of hub ATGs was assessed by receiver operating characteristic curve analysis.

RESULTS

Three modules (Brown, Turquoise, and Green) in GSE8157, three modules (Blue, Red, and Green) in GSE43264, and four modules (Blue, Green, Black, and Yellow) in GSE106724 were identified to be PCOS-related by WGCNA analysis. 29 ATGs were found to be the hub genes that strongly correlated with PCOS. These hub ATGs were mainly enriched in autophagy-related functions and pathways such as autophagy, endocytosis, apoptosis, and mTOR signaling pathways. The mRNA-miRNA-lncRNA multifactorial network was successfully constructed. And three new molecular subgroups were identified via the K-means algorithm.

DISCUSSION

We provide a novel insight into the mechanisms behind autophagy in PCOS. BRCA1, LDLR, MAP1B, hsa-miR-92b-3p, hsa-miR-20b-5p, and NEAT1 might play a considerably important role in PCOS dysfunction. As a result, new potential biomarkers can be evaluated for use in PCOS diagnosis and treatment in the future.

Increased Expression of YAP Inhibited the Autophagy Level by Upregulating mTOR Signal in the Eutopic ESCs of Endometriosis

We first reported that the Hippo-YAP signaling pathway plays a critical role in the pathogenesis of endometriosis (EMS). Autophagy is also related to the invasion ability of endometrial cells and is involved in the pathogenesis of EMS through multi-levels. However, the precise regulatory mechanism of YAP on autophagy in the eutopic endometrial stromal cells (ESCs) is still unclear. Primary eutopic ESCs of EMS patients (n = 12) and control patients without EMS (n = 9) were isolated and cultured to investigate the expressions of YAP and mTOR, the role of YAP in autophagy, and the effect of the YAP-autophagy signal on the decidualization of the eutopic ESCs. Endometriosis-related sequencing data (GSE51981) in the GEO database were used to find the genes significantly correlated with YAP. We found 155 genes with significant differences in the interaction with YAP in EMS from the dataset, and the autophagy pathway was significantly enriched. Following on from our previous studies of YAP knockdown, overexpression of YAP resulted in an increased expression of mTOR and decreased ratio of LC3-II/LC3-I and autophagy markers, in the eutopic ESCs; transmission electron microscope observation also showed fewer autophagosomes compared with the control cells. Furthermore, ESCs of the Rapamycin-treated group showed significant decidual-like changes with significantly increased decidual prolactin level at 72 h after in vitro decidualization. These results demonstrate that the increased YAP inhibited the level of autophagy by upregulating the mTOR signal in the eutopic ESCs of endometriosis. The YAP-autophagy signal plays an important role in the pathogenesis of endometriosis-associated infertility.

Autophagy as a Therapeutic Target of Natural Products Enhancing Embryo Implantation

Infertility is an emerging health issue worldwide, and female infertility is intimately associated with embryo implantation failure. Embryo implantation is an essential process during the initiation of prenatal development. Recent studies have strongly suggested that autophagy in the endometrium is the most important factor for successful embryo implantation. In addition, several studies have reported the effects of various natural products on infertility improvement via the regulation of embryo implantation, embryo quality, and endometrial receptivity. However, it is unclear whether natural products can improve embryo implantation ability by regulating endometrial autophagy. Therefore, we performed a literature review of studies on endometrial autophagy, embryo implantation, natural products, and female infertility. Based on the information from these studies, this review suggests a new treatment strategy for female infertility by proposing natural products that have been proven to be safe and effective as endometrial autophagy regulators; additionally, we provide a comprehensive understanding of the relationship between the regulation of endometrial autophagy by natural products and female infertility, with an emphasis on embryo implantation.

Down-Regulation of Casein Kinase 1α Contributes to Endometriosis through Phosphatase and Tensin Homolog/Autophagy-Related 7-Mediated Autophagy

The present study aimed to explore the roles of casein kinase 1α (CK1α) in endometriosis and its underlying mechanisms. Endometrial specimen were collected from the patients and healthy volunteers. The expression patterns of CK1α, phosphatase and tensin homolog (PTEN), and autophagy-related proteins were determined using immunohistochemistry staining, Western blot analysis, and quantitative RT-PCR. Besides, the CK1α-overexpressing cells and PTEN knockdown cells were constructed in the endometrial stromal cells isolated from endometriosis patients. In addition, the cells were transfected with pcDNA3.1-CK1α or pcDNA3.1-CK1α plus siRNA- PTEN. The expressions of CK1α, PTEN, and autophagy-related proteins were determined using Western blot and quantitative RT-PCR. The expressions of CK1α and autophagy-related 7 (Atg7) were significantly decreased in the ectopic endometrium compared with the eutopic endometrium. Spearman rank correlation analysis revealed positive correlations between CK1α and PTEN, CK1α and Atg7, and PTEN and Atg7. In addition, CK1α, PTEN, and autophagy-related proteins were down-regulated in ectopic endometrium. Interestingly, overexpression of CK1α significantly increased the expressions of autophagy-related proteins, whereas the protein expression of autophagy-related proteins was decreased with PTEN knock-down. CK1α regulated PTEN/Atg7-mediated autophagy in endometriosis.

Identification and Analysis of Potential Autophagy-Related Biomarkers in Endometriosis by WGCNA

Background: Endometriosis is a serious gynecological disorder characterized by debilitating pain, infertility and the establishment of innervated endometriosis lesions outside the uterus. Early detection and accurate diagnosis are pivotal in endometriosis. The work screened autophagy-related genes (ATGs) as potential biomarkers to reveal new molecular subgroups for the early diagnosis of endometriosis.

Materials and Methods: The gene lists of ATGs from five databases were integrated. Then, weighted gene co-expression network analysis (WGCNA) was used to map the genes to the gene profile of endometriosis samples in GSE51981 to obtain functional modules. GO and KEGG analyses were performed on the ATGs from the key modules. Differentially expressed ATGs were identified by the limma R package and further validated in the external datasets of GSE7305 and GSE135485. The DESeq2 R package was utilized to establish multifactorial network. Subsequently, one-way analysis of variance (ANOVA) was performed to identify new molecular subgroups. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting were used to confirm the differential expression of hub ATGs, and the receiver operating characteristic (ROC) curve analysis and Spearman correlation analysis were applied to assess the diagnostic value of hub ATGs in 40 clinical samples and human primary endometrial stromal cells (ESCs).

Results: We screened 4 key modules and 12 hub ATGs and found the key genes to be strongly correlated with endometriosis. The pathways of ATGs were mainly enriched in autophagy, apoptosis, ubiquitin-protein ligase binding, and MAPK signaling pathway. The expression levels of EZH2 (Enhancer of Zeste homolog 2) and RND3 (also known as RhoE) had statistically significant changes with higher values in the endometriosis group compared with the controls, both in the tissue samples and primary ESCs. Besides, they also showed higher specificity and sensitivity by the receiver operating characteristic analysis and Spearman correlation analysis for the diagnosis of endometriosis. The TF-mRNA-miRNA-lncRNA multifactorial network was successfully constructed. Four new molecular subgroups were identified, and we preliminarily showed the ability of IQCG to independently differentiate subgroups.

Conclusion: EZH2 and RND3 could be candidate biomarkers for endometriosis, which would contribute to the early diagnosis and intervention in endometriosis.

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.

miR-140-3p regulates the osteogenic differentiation ability of bone marrow mesenchymal stem cells by targeting spred2-mediated autophagy

Understanding the function and regulatory mechanism of miR-140-3p on the osteogenic differentiation of bone mesenchymal stem cells (BMSCs). Alizarin Red staining, Alkaline phosphatase (ALP) staining, and ALP activity were used to detect the ability osteogenic differentiation. miR-140-3p or Spred2 overexpression into BMSCs using lentiviral vectors and the result were analyzed by Reverse transcription quantitative polymerase chain reaction (RT-qPCR). The relation between miR-140-3p and Spred2 was examined by luciferase reporter assay. CCK8 assay was used to detect the proliferation of BMSCs. RT-qPCR and Western blot analysis were both used to detect altered gene and protein in osteogenic differentiation of BMSCs, respectively. The BMSCs which were induced for 21 days were analyzed by Alizarin Red staining, (ALP) staining and ALP activity. RT-qPCR analysis showed that overexpressed miR-140-3p promotes osteogenic differentiation. Western blots results indicated that the overexpression of Spred2 suppressed miR-140-3p. Luciferase reporter assay indicated that Spred2 can integrate with miR-140-3p directly. Meanwhile, the protein level of ALP, OCN, and Runx2, the markers of chondrogenesis, was increased when miR-140-3p increased or Spred2 overexpressed in the osteoinductive medium applied to the BMSCs. Our study demonstrated the association between miR-140-3p and Spred2 in osteogenic differentiation of BMSCs for the first time. Furthermore, our detections also revealed that Spred2-induced autophagic signaling accelerates the progress of osteogenic differentiation ability of BMSCs.

Hypo-Expression of Tuberin Promotes Adenomyosis via the mTOR1-Autophagy Axis

Adenomyosis (AM) is a disease in which endometrial tissue invades the myometrium and has a 10–60% prevalence in reproductive-aged women. TSC2 regulates autophagy via mTOR1 signalling in colorectal cancer and endometrial carcinoma. Dysregulation of autophagy is implicated in adenomyosis pathogenesis. However, whether TSC2 participates in adenomyosis via autophagy remains obscure. Here, we found that the expression of TSC2 in adenomyosis was significantly decreased than that in normal endometrium during the secretory phase. Moreover, TSC2 and autophagy marker expression was significantly lower in ectopic lesions than in eutopic samples. TSC2 downregulation inhibited autophagy through mTOR1 signalling pathway activation in endometrial cells, leading to excessive proliferation, migration, and EMT; TSC2 overexpression induced the opposite effects. Rapamycin treatment suppressed cell proliferation, migration and EMT in the absence of TSC2. In parallel, an autophagy-specific inhibitor (SAR-405) restored migration and EMT under rapamycin treatment in TSC2-knockdown Ishikawa cells. Finally, SAR-405 treatment promoted EMT and migration of overexpressing cells. Collectively, our results suggest that TSC2 controls endometrial epithelial cell migration and EMT by regulating mTOR1-autophagy axis activation and that hypo-expression of TSC2 in the endometrium might promote adenomyosis.

Pharmaceuticals targeting signaling pathways of endometriosis as potential new medical treatment: A review

Endometriosis (EM) is defined as endometrial tissues found outside the uterus. Growth and development of endometriotic cells in ectopic sites can be promoted via multiple pathways, including MAPK/MEK/ERK, PI3K/Akt/mTOR, NF-κB, Rho/ROCK, reactive oxidative stress, tumor necrosis factor, transforming growth factor-β, Wnt/β-catenin, vascular endothelial growth factor, estrogen, and cytokines. The underlying pathophysiological mechanisms include proliferation, apoptosis, autophagy, migration, invasion, fibrosis, angiogenesis, oxidative stress, inflammation, and immune escape. Current medical treatments for EM are mainly hormonal and symptomatic, and thus the development of new, effective, and safe pharmaceuticals targeting specific molecular and signaling pathways is needed. Here, we systematically reviewed the literature focused on pharmaceuticals that specifically target the molecular and signaling pathways involved in the pathophysiology of EM. Potential drug targets, their upstream and downstream molecules with key aberrant signaling, and the regulatory mechanisms promoting the growth and development of endometriotic cells and tissues were discussed. Hormonal pharmaceuticals, including melatonin, exerts proapoptotic via regulating matrix metallopeptidase activity while nonhormonal pharmaceutical sorafenib exerts antiproliferative effect via MAPK/ERK pathway and antiangiogenesis activity via VEGF/VEGFR pathway. N-acetyl cysteine, curcumin, and ginsenoside exert antioxidant and anti-inflammatory effects via radical scavenging activity. Natural products have high efficacy with minimal side effects; for example, resveratrol and epigallocatechin gallate have multiple targets and provide synergistic efficacy to resolve the complexity of the pathophysiology of EM, showing promising efficacy in treating EM. Although new medical treatments are currently being developed, more detailed pharmacological studies and large sample size clinical trials are needed to confirm the efficacy and safety of these treatments in the near future.

The Effect of Combined Oral Contraceptive Pills on Beclin-1 and LC3B Transcript Levels in Ovarian Endometrioma

Background

Autophagy is likely altered in patients with endometriosis. Ovarian steroid hormones seem to affect this changing of the autophagic process.

Objective

To study the effect of combined oral contraceptive (COC) pills on the expression of autophagic-related gene BECN1 and LC3B in the ectopic and eutopic endometria of patients with endometriosis. Material and Methods. The present quasiexperimental study recruited 36 women (18–45 years old) with endometrioma and nonendometrioma who were scheduled for surgery. Patients with endometrioma were randomly assigned to either a no-treatment group (n = 12) or a COC group (n = 12). The COC group was prescribed a daily oral pill composed of 3 mg drospirenone and 0.03 mg ethinyl estradiol for 6 weeks before surgery. The control group (n = 12) was composed of women without endometrioma. Ectopic endometriotic and endometrium tissues were collected from the no-treatment and COC groups, whereas the only endometrium was collected from the control group. These tissues were used for real-time PCR to measure the expression of the BECN1 and LC3B genes.

Results

The baseline demographic data were not different among the three groups. The BECN1 gene expression in endometrium tissue in the COC group was significantly less than that in the no-treatment and control groups (P = 0.011 and 0.029, respectively). No significant difference of endometriotic cyst BECN1 and LC3B gene expression was found between COC and no treatment.

Conclusions

Oral COC pills for 6 weeks continuously before surgery decreased the eutopic endometrial expression (mRNA) of the BECN1 gene compared to those from healthy normal women and nontreated patients with an endometriotic cyst. The change in the expression of autophagy-related genes was more distinct in eutopic than ectopic endometria. This trial is registered with TCTR20170720002. Registered and enrolled the first patient on 20 July 2017.

Autophagy and Mitophagy Promotion in a Rat Model of Endometriosis

Endometriosis is a gynecological condition affecting patients in reproductive age. The aim of this paper was to assess the effects of the autophagy and mitophagy induction in a rat model of endometriosis. Endometriosis was induced by the injection of uterine fragments, and rapamycin (0. 5 mg/kg) was administered once per week. One week from the induction, rats were sacrificed, and laparotomy was performed to collect the endometriotic implants and to further process them for molecular analysis. Western blot analysis was conducted on explanted lesions to evaluate the autophagy pathway during the pathology. Elevated phospho-serine/threonine kinase (p-AKT) and mammalian target of rapamycin (mTOR) expressions were detected in vehicle-treated rats, while Beclin and microtubule-associated protein 1A/1B-light chain 3 II (LC3II) expressions were low. Additionally, samples collected from vehicle groups indicated low Bnip3, Ambra1, and Parkin expressions, demonstrating impaired autophagy and mitophagy. Rapamycin administration reduced p-AKT and mTOR expressions and increased Beclin and LC3II, Bnip3, Ambra1, and Parkin expressions, activating both mechanisms. We also evaluated the impact of the impaired autophagy and mitophagy pathways on apoptosis and angiogenesis. Rapamycin was administered by activating autophagy and mitophagy, which increased apoptosis (assessed by Western blot analysis of Bcl-2, Bax, and Cleaved-caspase 3) and reduced angiogenesis (assessed by immunohistochemical analysis of vascular endothelial grow factor (VEGF) and CD34) in the lesions. All of these mechanisms activated by the induction of the autophagy and mitophagy pathways led to the reduction in the lesions’ volume, area and diameter.

AMPK/mTOR downregulated autophagy enhances aberrant endometrial decidualization in folate-deficient pregnant mice

Existing evidence suggests that adverse pregnancy outcomes are closely related to dietary factors. Folate plays an important role in neural tube formation and fetal growth, folate deficiency is a major risk factor of birth defects. Our early studies showed that folate deficiency could impair enddecidualization, however, the mechanism is still unclear. Dysfunctional autophagy is associated with many diseases. Here, we aimed to evaluate the adverse effect of folate deficiency on endometrial decidualization, with a particular focus on endometrial cell autophagy. Mice were fed with no folate diet in vivo and the mouse endometrial stromal cell was cultured in a folate-free medium in vitro. The decrease of the number of endometrial autophagosomes and the protein expressions of autophagy in the folate-deficient group indicated that autophagosome formation, autophagosome-lysosome fusion, and lysosomal degradation were inhibited. Autophagic flux examination using mCherry-GFP-LC3 transfection showed that the fusion of autophagosomes with lysosomes was inhibited by folate deficiency. Autophagy inducer rapamycin could reverse the impairment of folate deficiency on endometrial decidualization. Moreover, folate deficiency could reduce autophagy by disrupting AMPK/mTOR signaling, resulting in aberrant endometrial decidualization and adverse pregnancy outcomes. Further co-immunoprecipitation examination showed that decidual marker protein Hoxa10 could interact with autophagic marker protein Cathepsin L, and the interaction was notably reduced by folate deficiency. In conclusion, AMPK/mTOR downregulated autophagy was essential for aberrant endometrial decidualization in early pregnant mice, which could result in adverse pregnancy outcomes. This provided some new clues for understanding the causal mechanisms of birth defects induced by folate deficiency.

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.

Dexmedetomidine postconditioning suppresses myocardial ischemia/reperfusion injury by activating the SIRT1/mTOR axis

Myocardial ischemia/reperfusion (MI/R) triggers a complicated chain of inflammatory reactions. Dexmedetomidine (Dex) has been reported to be important in myocardial disorders. We evaluated the role of Dex in MI/R injury via the silent information regulator factor 2-related enzyme 1 (SIRT1)/mammalian target of rapamycin (mTOR) signaling pathway. First, Dex was immediately injected into rat models of MI/R injury during reperfusion. After Evans Blue-triphenyl tetrazolium chloride (TTC) and Hematoxylin-Eosin (H-E) staining, MI/R injury was observed. The extracted serum and myocardial tissues were used to detect oxidative stress and the inflammatory response. Western blot analysis was performed to evaluate MI/R autophagy and the levels of proteins associated with the SIRT1/mTOR axis. The effects of the combination of Dex and SIRT1 inhibitor EX527 on MI/R injury and autophagy were evaluated. Finally, the mechanism of Dex was tested, and autophagy levels and the levels of proteins associated with the SIRT1/mTOR signaling pathway were assessed in MI/R rats. The results of the present study suggested that Dex relieved MI/R injury, reduced cardiomyocyte apoptosis, oxidative stress and inflammatory reactions, up-regulated the SIRT1/mTOR axis and decreased overautophagy in MI/R rats. SIRT1 inhibitor EX527 attenuated the protective effects of Dex. Our study demonstrated that Dex alleviated MI/R injury by activating the SIRT1/mTOR axis. This investigation may offer new insight into the treatment of MI/R injury.

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.

Nuclear factor-kappa B signaling in endometriotic stromal cells is not inhibited by progesterone owing to an aberrant endoplasmic reticulum stress response: a possible role for an altered inflammatory process in endometriosis

Endoplasmic reticulum (ER) stress serves as a key modulator of the inflammatory response by controlling nuclear factor-kappaB (NF-κB) signaling. Previous studies from our laboratory have reported an abnormal induction of ER stress linked to progesterone resistance in human endometriotic cells. Therefore, an aberrant ER stress response to progesterone might contribute to the altered inflammatory response observed in endometriotic tissues. To evaluate this hypothesis, we investigated whether ER stress is involved in regulation of NF-κB in endometrial stromal cells and whether induction of aberrant ER stress in endometriotic stromal cells affects pro-inflammatory cytokine production. We found that tunicamycin-induced ER stress inhibited NF-κB activation and pro-inflammatory cytokine (IL-6 and COX2) production in TNF-α- or IL-1β-treated normal endometrial stromal cells (NECSs). Tunicamycin increased the expression of A20 and C/EBPβ, which are negative regulators of NF-κB, and this increase inhibited NF-κB activity in NESCs incubated with TNF-α or IL-1β. Similarly, progesterone increased A20 and C/EBPβ expression through upregulation of ER stress in NESCs, resulting in inhibition of NF-κB activity and IL-6 and COX2 production. However, progesterone had no significant effects on induction of ER stress, A20 or C/EBPβ expression, NF-κB activity or IL-6 or COX2 production in ovarian endometriotic cyst stromal cells (ECSCs). In contrast, upregulation of ER stress by tunicamycin significantly reduced IL-6 and COX2 production by inhibiting NF-κB activity in ECSCs. In conclusion, our results suggest that NF-κB activity in endometriotic stromal cells was not inhibited because of an aberrant ER stress response to progesterone, resulting in an increase in pro-inflammatory cytokine production.

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.

Induction of autophagy by Beclin-1 in granulosa cells contributes to follicular progesterone elevation in ovarian endometriosis

Endometriosis is a common gynecological disease in which ovarian dysfunction can be an important cause of infertility. Elevated progesterone (P4) levels during the follicular phase is possibly associated with impaired oocyte quality and pregnancy outcome in endometriosis. Beclin-1 (BECN1), an essential mediator of autophagy, has been shown to be related to the development and progression of endometriosis. This study aimed to investigate the autophagic activity in ovarian granulosa cells (GCs) of patients with endometriosis and to clarify the role of BECN1 in preovulatory P4 elevation. Our results demonstrated that serum P4/estradiol (E2) ratio and P4-to-follicle index (the average P4 secretion per follicle) on the day of human chorionic gonadotropin administration were elevated in women with ovarian endometriosis. Increased expression of BECN1 and enhanced autophagy were observed in GCs of patients with ovarian endometriomas. In cultured GCs, BECN1 knockdown reduced P4 secretion and the expression of key steroidogenic enzymes; whereas overexpression of BECN1 resulted in induced P4 production with activated biosynthesis pathway. Moreover, inhibition of autophagy by BECN1 knockdown significantly attenuated low-density lipoprotein (LDL)-induced P4 synthesis. These findings provide new insights into the role of BECN1 in late follicular P4 elevation in patients with endometriosis by promoting the degradation pathway of LDL for P4 biosynthesis via lysosome activation in GCs, and have potential therapeutic implications for the improvement of oocyte quality in women affected by endometriosis.

NLRC5 Inhibits Inflammation of Secretory Phase Ectopic Endometrial Stromal Cells by Up-Regulating Autophagy in Ovarian Endometriosis

Nod-like receptor (NLR) family caspase activation and recruitment domain containing 5 (NLRC5) is a newly identified sub-class of the NLR family. It regulates inflammation and has a key function in innate and adaptive immunologic reactions. Autophagy has been reported to be crucially linked to the pathogenesis of endometriosis. Our recent study identify there is a negative correlation between NLRC5 and autophagy in endometriosis, indicating that NLRC5 and autophagy together act as promising predictors in endometriosis patients. However, the mechanism associating NLRC5 and autophagy in endometriosis is still not completely understood. We hypothesize that autophagy could be involved in NLRC5-mediated inflammation in endometriosis. In order to validate the assumption, we evaluate the effects of NLRC5 and autophagy in the inflammation of ectopic endometrial stromal cells (EESCs) of ovarian endometriosis patients, to specifically determine whether autophagy is involved in NLRC5-mediated inflammation in EESCs. Our results show that over-expression of NLRC5 results in the up-regulation of autophagy in EESCs and inhibition of NLRC5 restricts the level of autophagy in EESCs. Furthermore, over-expression of NLRC5 and promotion of autophagy inhibit interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expressions, whereas inhibition of NLRC5 and autophagy up-regulate IL-6 and TNF-α expressions in EESCs. Additionally, promotion of autophagy contributes to the NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs; inhibition of autophagy restricts NLRC5-mediated inhibition of IL-6 and TNF-α expressions in EESCs. Our results suggest that over-expression of NLRC5 promotes autophagy, thereby inhibiting inflammation in ovarian endometriosis.

Involvement of endoplasmic reticulum stress in regulation of endometrial stromal cell invasiveness: possible role in pathogenesis of endometriosis

Endoplasmic reticulum (ER) stress is known to reduce invasiveness in some cancer cells by inhibiting the AKT/mTOR pathway. A previous study from our laboratory suggested that ER stress is promoted by progesterone in human endometrial cells, which suggests that progesterone may inhibit endometrial cell invasiveness by up-regulating ER stress. Therefore, aberrant ER stress in response to progesterone may contribute to the altered invasiveness found in endometriotic tissues. To test this hypothesis, we elucidate whether ER stress is involved in regulation of human endometrial cell invasiveness through the AKT/mTOR pathway and if this involvement is associated with altered invasiveness in endometriotic cells. Specifically, we sought to determine the effects of ER stress on AKT/mTOR pathway by evaluating ER stress-mediated CHOP/TRIB3 signaling, a negative regulator of AKT. We found that ER stress marker GRP78 expression increased with CHOP and TRIB3 expression in normal endometrial stromal cells (NESCs) treated with tunicamycin, and this increase was accompanied by decreased AKT and mTOR activity and cellular invasiveness. Similarly, progesterone increased GRP78, CHOP and TRIB3 expression in NESCs. Subsequently, inhibition of AKT and mTOR activity decreased cellular invasiveness. This progesterone-induced decrease in cellular invasiveness was reversed by inhibition of ER stress. In contrast, progesterone did not change CHOP, TRIB3, AKT, mTOR or invasiveness in endometriotic cyst stromal cells. In contrast to normal endometrium, endometriotic tissues showed no changes in CHOP, TRIB3 and invasion-related proteins (MMP2 and MMP9) expression throughout the menstrual cycle. Taken together, our findings indicate that abnormal ER stress response to progesterone increased endometriotic stromal cell invasiveness via the AKT/mTOR pathway.

Enriched Environment Decelerates the Development of Endometriosis in Mouse

We tested the hypothesis that enriched environment (EE), consisting of enlarged space, and increased physical activity and social interactions, hinders the development of endometriosis through attenuated adrenergic signaling, enhanced autophagy, and reduced leptin levels. Two mouse experiments were performed. In Experiment 1, 40 female Balb/C mice were randomly divided into four equal-sized groups, the SE (standard environment), EE, p-EE (EE instituted after endometriosis induction), and the d-EE (SE housing but received uterine fragments from EE donors) groups. Housing intervention was initiated 3 weeks before the induction of endometriosis and continued for 3 weeks after induction. In Experiment 2, 20 female mice were randomly divided into SE and EE groups, and the plasma leptin levels were measured. We measured lesion weight and hotplate latency and performed Masson trichrome staining as well as immunohistochemistry analysis of β2 adrenergic receptor (ADRB2), dopamine receptor D2 (DRD2), vascular endothelial growth factor (VEGF), and microtubule-associated protein light chain 3 (LC3). We found that EE reduced the lesion weight by 40.8% as compared with SE mice, but the reduction in p-EE and d-EE mice did not reach statistical significance. EE significantly reduced staining levels of ADRB2 and VEGF as well as the extent of lesional fibrosis but increased staining levels of LC3 and DRD2 in lesions as compared with the SE group. EE mice had reduced plasma leptin levels as compared with SE mice. Thus, EE decelerates the development of endometriosis and fibrogenesis and improved generalized hyperalgesia, possibly through increased DRD2 expression but decreased expression of ADRB2 and VEGF as well as enhanced autophagy and reduced leptin level.

Compound Porcine Cerebroside and Ganglioside Injection (CPCGI) Attenuates Sevoflurane-Induced Nerve Cell Injury by Regulating the Phosphorylation of p38 MAP Kinase (p38MAPK)/Nuclear Factor kappa B (NF-κB) Pathway

Background

Compound porcine cerebroside and ganglioside injection (CPCGI) has been widely applied in clinical practice in China to treat functional confusion caused by brain diseases. Sevoflurane, a frequently-used inhalational anesthetic, was discovered to have neurotoxicity that can cause neurological damage in patients. The present study was performed to investigate the protective effect of CPCGI on sevoflurane-induced nerve damage and to reveal the neuroprotective mechanisms of CPCGI.

Material/Methods

Firstly, the hippocampal neurons were separated from Sprague-Dawley embryonic rats, and were stimulated by 3% sevoflurane for different times (0, 2, 4, and 6 h). Then, cell viability and cell apoptosis were assessed by thiazolyl blue tetrazolium bromide (MTT) and flow cytometry (FCM), respectively. Western blot analysis was used to determine the apoptosis-related protein expression levels.

Results

The results demonstrated that 3% sevoflurane significantly inhibited cell viability but induced cell apoptosis in neurons in a time-dependent manner. Treatment with 3% sevoflurane also promoted the Bax [B cell leukemia/lymphoma 2 (Bcl2)-associated X protein] and cleaved caspase3 protein expressions, and suppressed Bcl-2 and pro-caspase3 expressions in hippocampal neurons. In addition, phosphorylated (p)-p38 and p-p65 expression and the ratio of p-p38/p38 and p-p65/p65 were upregulated in a time-dependent manner after 3% sevoflurane treatment. Further analysis indicated that all the effects of 3% sevoflurane on hippocampal neurons were reversed by CPCGI pre-treatment.

Conclusions

We demonstrated the neuroprotective role of CPCGI in sevoflurane-stimulated neuronal cell damage via regulation of the MAPK/NF-κB signaling pathway.

Increased expression of YAP is associated with decreased cell autophagy in the eutopic endometrial stromal cells of endometriosis

Basic research has shown that signal pathways play significant roles in the development and progression of endometriosis (EMS). We first reported that the Hippo-YAP (Yes-associated protein) pathway promotes cell proliferation and anti-apoptosis in endometrial stromal cells (ESCs) of EMS. Cell autophagy has been found to be involved in the endometrial regulation and the pathophysiology of EMS. We speculated that there may be an elaborate dialogue between Hippo-YAP and autophagy pathway in EMS. To explore this, we performed molecular biology experiments to investigate the expressions of YAP pathway and cell autophagy markers (mTOR, LC-3) in ESCs of women with or without EMS and detected the protein levels of autophagy markers after verteporfin and rapamycin treatments and the transfection with YAP-knockdown vector in the eutopic ESCs, respectively. We found that the mRNAs of YAP and mTOR were increased in the eutopic ESCs compared with controls, but no statistically difference, while the protein levels were significantly increased in the eutopic ESCs. Conversely, the ratio of the autophagy marker protein LC3-II/LC3-I was significantly decreased in the eutopic ESCs compared with controls. Moreover, verteporfin treatment interfered with the YAP function, but it had no effect on mTOR expression and cell autophagy level. Rapamycin treatment and YAP knockdown in the eutopic ESCs both inhibited the expression of YAP and increased the ratio of LC3-II/LC3-I significantly. These results demonstrate that the decreased cell autophagy level is associated with the increased expression of YAP and YAP may participate in the mTOR-autophagy pathway in the eutopic ESCs of endometriosis.

Role of Endometrial Autophagy in Physiological and Pathophysiological Processes

Endometrium is the mucosal lining of the uterus which expressed a cyclic process of proliferation, secretion and scaling under the control of hormones secreted by the ovary, and it also plays an indispensable role in the embryo implantation, the constitution of fetal-maternal interface, and the maintaining of pregnancy. In pathophysiological conditions, the abnormality or disorder of endometrium may lead to endometrium-related diseases, such as endometriosis, endometrium hyperplasia and even endometrial carcinoma. In recent years, more and more evidence revealed that autophagy exists in both the endometrium stroma cells and epithelial cells, and the activity of autophagy is changed in the different phases of menstruation, as well as in the endometrium-related diseases. Here, we aim to review the activity level, the regulatory factors and the function of autophagy in physiological and pathophysiological endometria, and to discuss the potential value of autophagy as a target for therapies of endometrium-related diseases.

Role of mTOR Signaling in Female Reproduction

Mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase of the phosphatidylinositol kinase-related kinase family that regulates cell growth, metabolism, and autophagy. Extensive research has linked mTOR to several human diseases including cancer, neurodegenerative disorders, and aging. In this review, recent publications regarding the mechanisms underlying the role of mTOR in female reproduction under physiological and pathological conditions are summarized. Moreover, we assess whether strategies to improve or suppress mTOR expression could have therapeutic potential for reproductive diseases like premature ovarian failure, polycystic ovarian syndrome, and endometriosis.

Autophagy induces G0/G1 arrest and apoptosis in menstrual blood-derived endometrial stem cells via GSK3-β/β-catenin pathway

BACKGROUND/AIMS

Menstrual blood-derived endometrial stem cells (MenSCs) emerge as an ideal source for cell-based treatment in regenerative medicine and immunotherapy. However, the major obstacle is the low survival rate in tissues and the limited expansion number. Autophagy is an intracellular metabolic self-degradative process which plays important roles in normal cellular division and survival, and the present study aimed to explore the related mechanisms between autophagy and survival of MenSCs in vitro and in vivo.

METHODS

The MenSCs were obtained from menstrual blood procured from healthy female donors. In vitro, MenSCs were exposed to rapamycin and Earle's balanced salts solution (EBSS). We evaluated the MenSCs immunophenotypic cell cycle distribution by propidium iodide (PI) staining and cell apoptosis by Annexin V/PI staining as well as their proliferative potential by the MTT assay. We also assessed the expression of genes associated with the cell cycle and Gsk3β signaling pathway by western blot analysis. We depressed Atg5 and Gsk3β expression by short hairpin RNA (shRNA) and undertook the experiments. Moreover, the labeled MenSCs were observed and counted with DiI after transplantation into the mice via the tail vein by microscopy in vivo.

RESULTS

In vitro, rapamycin and starvation induced autophagy of MenSCs. Hyperactive autophagy significantly induced G0/G1 arrest and slightly promoted apoptosis of MenSCs. Meanwhile, autophagy could stimulate p-GSK3β expression in MenSCs. Further, knockdown GSK3β can accelerate the proliferation of MenSCs by shRNA and CHIR99021. Moreover, the shGSK3β MenSCs showed strong proliferative activity in vitro and in vivo.

CONCLUSIONS

Our results indicate that autophagy induced G0/G1 arrest and apoptosis of MenSCs via GSK3β/β-catenin pathway. Inhibiting autophagy or reduced GSK3β levels may improve survival rate in vivo, thus playing roles in MenSCs therapy.

Long non-coding RNA MALAT1 mediates hypoxia-induced pro-survival autophagy of endometrial stromal cells in endometriosis

Endometriosis is a common gynecological disease characterized by diminished apoptosis, sustained ectopic survival of dysfunctional endometrial cells. Hypoxia has been implicated as a crucial microenvironmental factor that contributes to endometriosis. It has been reported that long non‐coding RNA MALAT1 (lncRNA‐MALAT1) highly expressed in endometriosis and up‐regulated by hypoxia. Hypoxia may also induce autophagy, which might act as cell protective mechanism. However, the relationship between lncRNA‐MALAT1 and autophagy under hypoxia conditions in endometriosis remains unknown. In the present study, we found that both lncRNA‐MALAT1 and autophagy level were up‐regulated in ectopic endometrium from patients with endometriosis, and its expression level correlates positively with that of hypoxia‐inducible factor‐1α (HIF‐1α). In cultured human endometrial stromal cells, both lncRNA‐MALAT1 and autophagy were induced by hypoxia in a time‐dependent manner and lncRNA‐MALAT1 up‐regulation was dependent on HIF‐1α signalling. Our analyses also show that knockdown of lncRNA‐MALAT1 suppressed hypoxia induced autophagy. Furthermore, inhibiting autophagy with specific inhibitor 3‐Methyladenine (3‐MA) and Beclin1 siRNA enhanced apoptosis of human endometrial stromal cells under hypoxia condition. Collectively, our findings identify that lncRNA‐MALAT1 mediates hypoxia‐induced pro‐survival autophagy of endometrial stromal cells in endometriosis.

Autophagy Suppresses Invasiveness of Endometrial Cells through Reduction of Fascin-1

Objective

Autophagy has been reported to be involved in the development of various disorders such as neurodegenerative and metabolic diseases and tumors. Autophagy activators and inhibitors are also potential therapeutics for these diseases. However, the mechanism of autophagic involvement in different diseases is not the same, and the role of autophagy in endometriosis (EM) has not yet been elucidated. This research investigated the mechanism by which autophagy acts in EM, with the aim of establishing a theoretical basis for its prevention and treatment through the targeted interference with autophagy.

Methods

We used an RNA interference fragment targeting ATG5, the autophagy activator rapamycin, and the autophagy inhibitor 3-MA or overexpression of filopodia-related protein fascin-1, in conjunction with clonogenic assays, growth curves, and scratch assay to investigate the influence of autophagy on cellular growth, proliferation, and invasiveness. We collected specimens from 20 clinical cases of EM and investigated the protein expression of the autophagic marker LC3-II, the autophagic substrate p62, and fascin-1.

Results

Rapamycin was able to inhibit the proliferation and colony formation of the endometriotic cell line CRL-7566, whereas the autophagy inhibitor 3-MA as well as the interference with the autophagy-related gene ATG5 had the opposite effect. More importantly, the autophagy activator rapamycin was able to inhibit the growth of filopodia in the endometriotic cells, and the overexpression of the fascin-1 restored the rapamycin-induced decrease of invasiveness. We found that the expression of the autophagy marker LC3-II was significantly reduced among the clinical EM specimens compared to the control group, while the expressions of fascin-1 and autophagic substrate p62 were increased.

Conclusion

Our results indicate that the inhibition of autophagy and exogenous expression of fascin-1 may promote the invasiveness of endometrial cells. As a corollary, autophagy represents a potential target for the treatment of EM.

The ginsenoside PPD exerts anti-endometriosis effects by suppressing estrogen receptor-mediated inhibition of endometrial stromal cell autophagy and NK cell cytotoxicity

Endometriosis (EMS) is an estrogen-dependent gynecological disease with a low autophagy level of ectopic endometrial stromal cells (eESCs). Impaired NK cell cytotoxic activity is involved in the clearance obstruction of the ectopic endometrial tissue in the abdominopelvic cavity. Protopanaxadiol (PPD) and protopanaxatriol (PPT) are two metabolites of ginsenosides, which have profound biological functions, such as anti-cancer activities. However, the role and mechanism of ginsenosides and metabolites in endometriosis are completely unknown. Here, we found that the compounds PPD, PPT, ginsenoside-Rg3 (G-Rg3), ginsenoside-Rh2 (G-Rh2), and esculentoside A (EsA) led to significant decreases in the viability of eESCs, particularly PPD (IC50 = 30.64 µM). In vitro and in vivo experiments showed that PPD promoted the expression of progesterone receptor (PR) and downregulated the expression of estrogen receptor α (ERα) in eESCs. Treatment with PPD obviously induced the autophagy of eESCs and reversed the inhibitory effect of estrogen on eESC autophagy. In addition, eESCs pretreated with PPD enhanced the cytotoxic activity of NK cells in response to eESCs. PPD decreased the numbers and suppressed the growth of ectopic lesions in a mouse EMS model. These results suggest that PPD plays a role in anti-EMS activation, possibly by restricting estrogen-mediated autophagy regulation and enhancing the cytotoxicity of NK cells. This result provides a scientific basis for potential therapeutic strategies to treat EMS by PPD or further structural modification.