Suppression of autophagic activation in the mouse uterus by estrogen and progesterone

Enhancing endometrial receptivity: the roles of human chorionic gonadotropin in autophagy and apoptosis regulation in endometrial stromal cells

Inadequate endometrial receptivity often results in embryo implantation failure and miscarriage. Human chorionic gonadotropin (hCG) is a key signaling molecule secreted during early embryonic development, which regulates embryonic maternal interface signaling and promotes embryo implantation. This study aimed to examine the impact of hCG on endometrial receptivity and its underlying mechanisms. An exploratory study was designed, and endometrial samples were obtained from women diagnosed with simple tubal infertility or male factor infertile (n = 12) and recurrent implantation failure (RIF, n = 10). Using reverse transcription-quantitative PCR and western blotting, luteinizing hormone (LH)/hCG receptor (LHCGR) levels and autophagy were detected in the endometrial tissues. Subsequently, primary endometrial stromal cells (ESCs) were isolated from these control groups and treated with hCG to examine the presence of LHCGR and markers of endometrial receptivity (HOXA10, ITGB3, FOXO1, LIF, and L-selectin ligand) and autophagy-related factors (Beclin1, LC3, and P62). The findings revealed that the expressions of receptivity factors, LHCGR, and LC3 were reduced in the endometrial tissues of women with RIF compared with the control group, whereas the expression of P62 was elevated. The administration of hCG to ESCs specifically activated LHCGR, stimulating an increase in the endometrial production of HOXA10, ITGB3, FOXO1, LIF and L-selectin ligands. Furthermore, when ESCs were exposed to 0.1 IU/mL hCG for 72 h, the autophagy factors Beclin1 and LC3 increased within the cells and P62 decreased. Moreover, the apoptotic factor Bax increased and Bcl-2 declined. However, when small interfering RNA was used to knock down LHCGR, hCG was less capable of controlling endometrial receptivity and autophagy molecules in ESCs. In addition, hCG stimulation enhanced the phosphorylation of ERK1/2 and mTOR proteins. These results suggest that women with RIF exhibit lower levels of LHCGR and compromised autophagy function in their endometrial tissues. Thus, hCG/LHCGR could potentially improve endometrial receptivity by modulating autophagy and apoptosis.

Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

The role of autophagy in prostate cancer and prostatic diseases: a new therapeutic strategy

BACKGROUND

Autophagy is a well-conserved catabolic process that plays a key role in cell homeostasis. In the prostate, defective autophagy has been implicated in the genesis and progression of several pathological conditions.

AIM

The present review explored the autophagy pathway in prostate-related dysfunctions, focusing on prostate cancer (PCa), benign prostatic hyperplasia (BPH) and prostatitis.

RESULTS

Impaired autophagy activity has been shown in animal models of BPH and prostatitis. Moreover, autophagy activation by specific and non-specific drugs improved both conditions in pre-clinical studies. Conversely, the efficacy of autophagy inducers in PCa remains controversial, depending on intrinsic PCa characteristics and stage of progression. Intriguingly, autophagy inhibitors have shown beneficial effects in PCa suppression or even to overcome chemotherapy resistance. However, there are still open questions regarding the upstream mechanisms by which autophagy is deregulated in the prostate and the exact role of autophagy in PCa. The lack of specificity and increased toxicity associated with the currently autophagy inhibitors limits its use clinically, reflecting in reduced number of clinical data.

CONCLUSION

New therapeutic strategies to treat prostatic diseases involving new autophagy modulators, combination therapy and new drug formulations should be explored. Understanding the autophagy signaling in each prostatic disease is crucial to determine the best pharmacological approach.

The constructive and destructive impact of autophagy on both genders' reproducibility, a comprehensive review

Reproduction is characterized by a series of massive renovations at molecular, cellular, and tissue levels. Recent studies have strongly tended to reveal the involvement of basic molecular pathways such as autophagy, a highly conserved eukaryotic cellular recycling, during reproductive processes. This review comprehensively describes the current knowledge, updated to September 2022, of autophagy contribution during reproductive processes in males including spermatogenesis, sperm motility and viability, and male sex hormones and females including germ cells and oocytes viability, ovulation, implantation, fertilization, and female sex hormones. Furthermore, the consequences of disruption in autophagic flux on the reproductive disorders including oligospermia, azoospermia, asthenozoospermia, teratozoospermia, globozoospermia, premature ovarian insufficiency, polycystic ovarian syndrome, endometriosis, and other disorders related to infertility are discussed as well.Abbreviations: AKT/protein kinase B: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; ATG: autophagy related; E2: estrogen; EDs: endocrine disruptors; ER: endoplasmic reticulum; FSH: follicle stimulating hormone; FOX: forkhead box; GCs: granulosa cells; HIF: hypoxia inducible factor; IVF: in vitro fertilization; IVM: in vitro maturation; LCs: Leydig cells; LDs: lipid droplets; LH: luteinizing hormone; LRWD1: leucine rich repeats and WD repeat domain containing 1; MAP1LC3: microtubule associated protein 1 light chain 3; MAPK: mitogen-activated protein kinase; MTOR: mechanistic target of rapamycin kinase; NFKB/NF-kB: nuclear factor kappa B; P4: progesterone; PCOS: polycystic ovarian syndrome; PDLIM1: PDZ and LIM domain 1; PI3K: phosphoinositide 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns3K: class III phosphatidylinositol 3-kinase; POI: premature ovarian insufficiency; ROS: reactive oxygen species; SCs: Sertoli cells; SQSTM1/p62: sequestosome 1; TSGA10: testis specific 10; TST: testosterone; VCP: vasolin containing protein.

Investigation of the Histopathological Effects of Hyperthyroidism on Endometrial Tissue in an Experimental Hyperthyroidism Rat Model

Objective: It was aimed to investigate histopathological changes of rat uterus in experimental hyperthyroidism. Methods: 16 new adult Wistar albino female rats weighing 200-220 g were used. Group 1 (Control group) were given 3 ml distilled water for 25 days, Group 2 was given 100 µg/day of L-thyroxine dissolved in 3 mL distilled water by oral gavage for 25 days. In the uterine tissue sections, incubation was performed with the Caspase 3 primary antibody to detect apoptotic cell death and LC3B primary antibody to detect autophagic cell death. Immunositivities were evaluated and histological examination was performed. Results: In terms of apoptotic cell death, no immunopositivity was observed in both group. Differences were found between the groups in terms of autophagic cell death. It was observed that there is hyperplasia in some places in epithelial cells and the cells undergo degenerative changes. In the endometrium, edematous areas and mononuclear inflammatory cell infiltrations were noted. Conclusion: We have observed that hyperthyroidism causes edematous and inflammatory changes in the endometrium of adult rats, increases autophagy. We believe that the increase in autophagy is due to the effect of increased inflammation and impaired homeostasis. Detailed molecular studies are needed to investigate the effects of hyperthyroidism at the tissue level.

Ovariectomy Affects Acute Pancreatitis in Mice

BACKGROUND

Serum estradiol levels in severe acute injury are correlated with in hospital mortality. In acute pancreatitis, serum estradiol levels are strong predictors of disease severity. Studies of whether changes in estradiol levels play a causative role in acute pancreatitis severity are limited. The ovariectomized mouse model has been used to study the effects of estradiol in health and disease.

AIMS

We assessed whether the ovariectomized mouse model could be used to assess the effects of estradiol on pancreatitis severity.

METHODS

C57BL/6 mice with their ovaries removed were used to simulate low circulating estradiol conditions. Ovariectomized mice were treated with six hourly injections of cerulein to induce mild acute pancreatitis and compared to ovariectomized mice pre-treated with subcutaneous estradiol injections.

RESULTS

Findings suggest ovariectomized model is a problematic preparation to study pancreatitis. At baseline, ovariectomy leads to prominent acinar cell ultrastructure changes as well as changes in other select morphologic and biomarkers of pancreatitis. In addition, ovariectomy changed select acute pancreatitis responses that were only partially rescued by estradiol pre-treatment.

CONCLUSIONS

These findings suggest that the ovariectomized mouse as a model of estradiol depletion should be used with caution in pancreatic studies. Future studies should explore whether derangements in other female hormones produced by the ovaries can lead to changes in pancreatic studies.

Peripubertal requirement of Tsg101 in maintaining the integrity of membranous structures in mouse oocytes

Objective

As a component of Endosomal Sorting Complex Required for Transport (ESCRT) complex I, the tumor susceptibility gene 101 (Tsg101) carries out multiple functions. In this work, we report that oocyte‐specific deletion of tumor susceptibility gene 101 (Tsg101) leads to age‐dependent oocyte demise in mice.

Materials and Method

Tsg101 floxed mice (Tsg101^f/f) were bred with Zp3^cre transgenic mice to examine oocyte‐specific roles of Tsg101. Multiple cellular and molecular biological approaches were taken to examine what leads to oocyte demise in the absence of Tsg101.

Results

The death of oocytes from Zp3^cre/Tsg101^f/f (Tsg101^d/d thereafter) mice showed a strong correlation with sexual maturation, as gonadotropin‐releasing hormone antagonist injections improved the survival rate of oocytes from 5‐week‐old Tsg101^d/d mice. Maturation of oocytes from prepubertal Tsg101^d/d mice proceeded normally, but was largely abnormal in oocytes from peripubertal Tsg101^d/d mice, showing shrinkage or rupture. Endolysosomal structures in oocytes from peripubertal Tsg101^d/d mice showed abnormalities, with aberrant patterns of early and late endosomal markers and a high accumulation of lysosomes. Dying oocytes showed plasma membrane blebs and leakage. Blockage of endocytosis in oocytes at 4°C prevented cytoplasmic shrinkage of oocytes from Tsg101^d/d mice until 9 h. The depletion of tsg‐101 in Caenorhabditis elegans increased the permeability of oocytes and embryos, suggesting a conserved role of Tsg101 in maintaining membrane integrity.

Conclusions

Collectively, Tsg101 plays a dual role in maintaining the integrity of membranous structures, which is influenced by age in mouse oocytes.

Estradiol (E2) Improves Glucose-Stimulated Insulin Secretion and Stabilizes GDM Progression in a Prediabetic Mouse Model

Female New Zealand obese (NZO) mice are an established model of preconceptional (pc.) prediabetes that progresses as gestational diabetes mellitus (GDM) during gestation. It is known that NZO mice show improvement in insulin sensitivity and glucose-stimulated insulin secretion (GSIS) during gestation in vivo. The latter is no longer detectable in ex vivo perifusion experiments in isolated islets of Langerhans, suggesting a modulation by extrapancreatic factors. Here, we demonstrated that plasma 17β-estradiol (E2) levels increased markedly in NZO mice during gestation. The aim of this work was to determine whether these increased E2 levels are responsible for the improvement in metabolism during gestation. To achieve this goal, we examined its effects in isolated islets and primary hepatocytes of both NZO and metabolically healthy NMRI mice. E2 increased GSIS in the islets of both strains significantly. Hepatic glucose production (HGP) failed to be decreased by insulin in NZO hepatocytes but was reduced by E2 in both strains. Hepatocytes of pregnant NZO mice showed significantly lower glucose uptake (HGU) compared with NMRI controls, whereby E2 stimulation diminished this difference. Hepatocytes of pregnant NZO showed reduced glycogen content, increased cyclic adenosine monophosphate (cAMP) levels, and reduced AKT activation. These differences were abolished after E2 stimulation. In conclusion, our data indicate that E2 stabilizes and prevents deterioration of the metabolic state of the prediabetic NZO mice. E2 particularly increases GSIS and improves hepatic glucose utilization to a lower extent.

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.

Estrogen inhibits endoplasmic reticulum stress and ameliorates myocardial ischemia/reperfusion injury in rats by upregulating SERCA2a

Background

The incidence of coronary heart disease (CHD) in premenopausal women is significantly lower than that of men of the same age, suggesting protective roles of estrogen for the cardiovascular system against CHD. This study aimed to confirm the protective effect of estrogen on myocardium during myocardial ischemia/reperfusion (MI/R) injury and explore the underlying mechanisms.

Methods

Neonatal rat cardiomyocytes and Sprague–Dawley rats were used in this study. Different groups were treated by bilateral ovariectomy, 17β-estradiol (E2), adenoviral infection, or siRNA transfection. The expression of sarcoplasmic reticulum Ca²⁺ ATPase pump (SERCA2a) and endoplasmic reticulum (ER) stress-related proteins were measured in each group to examine the effect of different E2 levels and determine the relationship between SERCA2a and ER stress. The cell apoptosis, myocardial infarction size, levels of apoptosis and serum cardiac troponin I, ejection fraction, calcium transient, and morphology changes of the myocardium and ER were examined to verify the effects of E2 on the myocardium.

Results

Bilateral ovariectomy resulted in reduced SERCA2a levels and more severe MI/R injury. E2 treatment increased SERCA2a expression. Both E2 treatment and exogenous SERCA2a overexpression decreased levels of ER stress-related proteins and alleviated myocardial damage. In contrast, SERCA2a knockdown exacerbated ER stress and myocardial damage. Addition of E2 after SERCA2a knockdown did not effectively inhibit ER stress or reduce myocardial injury.

Conclusions

Our data demonstrate that estrogen inhibits ER stress and attenuates MI/R injury by upregulating SERCA2a. These results provide a new potential target for therapeutic intervention and drug discovery in CHD.

Kruppel-like factor 5 (Klf5) in fetal-maternal tissue during periimplantation and effects of ovarian steroid hormone antagonist on its expression during uterine receptivity of albino mice

Background

Embryo implantation is a tightly regulated sequence of events regulated by ovarian steroids, estrogen and progesterone, and their downstream targets. Ovarian steroids regulate most of the genes involved in embryo implantation and pregnancy. However, some factors are not regulated by ovarian steroids, estrogen, progesterone, or both. Kruppel-like factor 5 (Klf5) is an example of an ovarian steroid–independent factor having a role in cellular proliferation, differentiation. The detailed expression profile of Klf5 during uterine receptivity and periimplantation has not been studied till now. In the present research work, an attempt was made to investigate the expression pattern of Klf5 in mice fetal-maternal tissue during periimplantation (day 4–day 8). The expressional and functional independence of Klf5 on the ovarian steroids was studied using estrogen and progesterone antagonist. The study was carried out in female Swiss albino mice of LACA strain during the periimplantation period. KLF5 was localized in the fetal-maternal tissues using the immunofluorescence technique in paraffin-embedded tissues. Ovarian steroid antagonists were administered subcutaneously from day 1 to day 3 of gestation, and the uterus was collected on the morning of day 4. Klf5 protein and mRNA levels were studied by western blot and quantitative real-time PCR (qPCR), respectively.

Results

KLF5 was localized in the embryo, uterine luminal epithelium, glandular epithelium, and proliferating stromal cells during periimplantation. In ovarian steroid antagonist–treated groups, KLF5 was localized in the luminal and glandular epithelium and stroma. Western blot and qPCR confirmed translation and transcription of KLF5 during the experimental period. The KLF5 protein level significantly increased on day 6, day 7, and day 8 when compared with day 4 (P < 0.05). The mRNA level of Klf5 increased significantly on day 7 and day 8 when compared with day 4 (P < 0.05). In ovarian steroid antagonist–treated groups, protein and mRNA corresponding to Klf5 were observed. From this finding, it can be assumed that Klf5 may be a steroid-independent factor expressed during uterine receptivity.

Conclusion

Spatiotemporal KLF5 expression in fetal-maternal tissue was observed during the experimental period. The results suggest that Klf5 is an ovarian steroid–independent factor that may play a pivotal role in implantation, decidualization, and embryogenesis.

Effect of 17β-Estradiol, Progesterone, and Tamoxifen on Neurons Infected with Toxoplasma gondii In Vitro

Toxoplasma gondii (T. gondii) is the causal agent of toxoplasmosis, which produces damage in the central nervous system (CNS). Toxoplasma-CNS interaction is critical for the development of disease symptoms. T. gondii can form cysts in the CNS; however, neurons are more resistant to this infection than astrocytes. The probable mechanism for neuron resistance is a permanent state of neurons in the interface, avoiding the replication of intracellular parasites. Steroids regulate the formation of Toxoplasma cysts in mice brains. 17β-estradiol and progesterone also participate in the control of Toxoplasma infection in glial cells in vitro. The aim of this study was to evaluate the effects of 17β-estradiol, progesterone, and their specific agonists-antagonists on Toxoplasma infection in neurons in vitro. Neurons cultured were pretreated for 48 h with 17β-estradiol or progesterone at 10, 20, 40, 80, or 160 nM/mL or tamoxifen 1 μM/mL plus 17β-estradiol at 10, 20, 40, 80, and 160 nM/mL. In other conditions, the neurons were pretreated during 48 h with 4,4',4″-(4-propyl-[1H] pyrozole-1,3,5-triyl) trisphenol or 23-bis(4-hydroxyphenyl) propionitrile at 1 nM/mL, and mifepristone 1 µM/mL plus progesterone at 10, 20, 40, 80, and 160 nM/mL. Neurons were infected with 5000 tachyzoites of the T. gondii strain RH. The effect of 17β estradiol, progesterone, their agonists, or antagonists on Toxoplasma infection in neurons was evaluated at 24 and 48 h by immunocytochemistry. T. gondii replication was measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. 17β-Estradiol alone or plus tamoxifen reduced infected neurons (50%) compared to the control at 48 h. Progesterone plus estradiol decreased the number of intracellular parasites at 48 h of treatment compared to the control (p < 0.001). 4,4',4″-(4-propyl-[1H] pyrozole-1,3,5-triyl) trisphenol and 23-bis(4-hydroxyphenyl) propionitrile reduced infected neurons at 48 h of treatment significantly compared to the control (p < 0.05 and p < 0.001, respectively). The Toxoplasma infection process was decreased by the effect of 17β-estradiol alone or combined with tamoxifen or progesterone in neurons in vitro. These results suggest the essential participation of progesterone and estradiol and their classical receptors in the regulation of T. gondii neuron infection.

The autophagy protein, FIP200 (RB1CC1) mediates progesterone responses governing uterine receptivity and decidualization†

Successful establishment of pregnancy depends on steroid hormone-driven cellular changes in the uterus during the peri-implantation period. To become receptive to embryo implantation, uterine endometrial stromal cells (ESCs) must transdifferentiate into decidual cells that secrete factors necessary for embryo survival and trophoblast invasion. Autophagy is a key homeostatic process vital for cellular homeostasis. Although the uterus undergoes major cellular changes during early pregnancy, the precise role of autophagy in uterine function is unknown. Here, we report that conditional knockout of the autophagy protein FIP200 in the reproductive tract of female mice results in reduced fecundity due to an implantation defect. In the absence of FIP200, aberrant progesterone signaling results in sustained uterine epithelial proliferation and failure of stromal cells to decidualize. Additionally, loss of FIP200 impairs decidualization of human ESCs. We conclude that the autophagy protein FIP200 plays a crucial role in uterine receptivity, decidualization, and fertility. These data establish autophagy as a major cellular pathway required for uterine receptivity and decidualization in both mice and human ESCs.

Tumor susceptibility gene 101 is required for the maintenance of uterine epithelial cells during embryo implantation

BACKGROUND

The tumor susceptibility gene 101 (Tsg101), a component of the endosomal sorting complex required for transport (ESCRT) complex I, is involved in multiple biological processes involving endomembranous structures and the plasma membrane. The role of Tsg101 in the uterine epithelium was investigated in Tsg101 floxed mice crossed with Lactoferrin-iCre mice (Tsg101^d/d).

METHODS

Tsg101^d/d mice were bred with stud male mice and the status of pregnancy was examined on days 4 and 6. Histological analyses were performed to examine the uterine architecture. Immunofluorescence staining of several markers was examined by confocal microscopy. Uterine epithelial cells (UECs) were isolated from Tsg101^f/f and Tsg101^d/d mice, and the expression of necroptosis effectors was examined by RT-PCR, western blotting, and immunofluorescence staining. UECs were also subjected to RNA expression profiling.

RESULTS

Tsg101^d/d female mice were subfertile with implantation failure, showing unattached blastocysts on day 6 of pregnancy. Histological and marker analyses revealed that some Tsg101^d/d day 4 pregnant uteri showed a disintegrated uterine epithelial structure. Tsg101^d/d UECs began to degenerate within 18 h of culture. In UECs, expression of necroptosis effectors, such as RIPK1, RIPK3, and MLKL were first confirmed. UECs responded to a stimulus to activate necroptosis and showed increased cell death.

CONCLUSIONS

Tsg101 deficiency in the uterine epithelium causes implantation failure, which may be caused by epithelial defects. This study provides evidence that UECs harbor a necroptotic machinery that responds to death-inducing signals. Thus, Tsg101 expression in the uterine epithelium is required for normal pregnancy in mice.

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.

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.

HIF-1α/BNIP3-Mediated Autophagy Contributes to the Luteinization of Granulosa Cells During the Formation of Corpus Luteum

During the luteinization after ovulation in mammalian ovary, the containing cells undergo an energy consuming function re-determination process to differentiate into luteal cells under avascular environment. Previous evidences have delineated the contribution of autophagy to the cell differentiation and the catabolic homeostasis in various types of mammalian cells, whereas few interest had been focused on the involvement of autophagy in the luteinization of granulosa cells during the formation of early corpus luteum. Herein, the present study investigated that expression and contribution of autophagy during granulosa cell luteinization and early luteal development through in vivo and in vitro experiments. The results clearly demonstrated that HIF-1α/BNIP3-mediated autophagy plays a vital role in the luteinization of granulosa cells during the early luteal formation in vivo and in vitro. In the neonatal corpus luteum, HIF-1α up-regulated BNIP3 expressions, which contributed to the autophagic initiation by disrupting beclin1 from Bcl-2/beclin1 complex and protected cells from apoptosis by curbing the skew of mitochondria balance under avascular niche. Notably, Inhibition of HIF-1α activity by echinomycin enhanced the levels of cytoplasmic cytochrome c and cell apoptosis in the nascent corpus luteum. These findings revealed that HIF-1α/BNIP3-mediated autophagy enabled the process of granulosa cell luteinization and protected the granulosa-lutein cells from further apoptosis under hypoxia niche. To our knowledge, the present study firstly clarified that HIF-1α/BNIP3-mediated autophagy contributes to the luteinization of granulosa cells during the formation of pregnant corpus luteum, which will help us further understanding the luteal biology and provide us new clues for the treatment of luteal insufficiency.

Autophagy in the uterine vessel microenvironment: Balancing vasoactive factors

Autophagy, which has the literal meaning of self-eating, is a cellular catabolic process executed by arrays of conserved proteins in eukaryotes. Autophagy is dynamically ongoing at a basal level, presumably in all cells, and often carries out distinct functions depending on the cell type. Therefore, although a set of common genes and proteins is involved in this process, the outcome of autophagic activation or deficit requires scrutiny regarding how it affects cells in a specific pathophysiological context. The uterus is a complex organ that carries out multiple tasks under the influence of cyclic changes of ovarian steroid hormones. Several major populations of cells are present in the uterus, and the interactions among them drive complex physiological tasks. Mouse models with autophagic deficits in the uterus are very limited, but provide an initial glimpse at how autophagy plays a distinct role in different uterine tissues. Herein, we review recent research findings on the role of autophagy in the uterine mesenchyme in mouse models.

Selective Inhibition of Coxiella burnetii Replication by the Steroid Hormone Progesterone

Coxiella burnetii is a zoonotic bacterial obligate intracellular parasite and the cause of query (Q) fever. During natural infection of female animals, C. burnetii shows tropism for the placenta and is associated with late-term abortion, at which time the pathogen titer in placental tissue can exceed one billion bacteria per gram. During later stages of pregnancy, placental trophoblasts serve as the major source of progesterone, a steroid hormone known to affect the replication of some pathogens. During infection of placenta-derived JEG-3 cells, C. burnetii showed sensitivity to progesterone but not the immediate precursor pregnenolone or estrogen, another major mammalian steroid hormone. Using host cell-free culture, progesterone was determined to have a direct inhibitory effect on C. burnetii replication. Synergy between the inhibitory effect of progesterone and the efflux pump inhibitors verapamil and 1-(1-naphthylmethyl)-piperazine is consistent with a role for efflux pumps in preventing progesterone-mediated inhibition of C. burnetii activity. The sensitivity of C. burnetii to progesterone, but not structurally related molecules, is consistent with the ability of progesterone to influence pathogen replication in progesterone-producing tissues.

Rapamycin prevents spontaneous abortion by triggering decidual stromal cell autophagy-mediated NK cell residence

Deficiency in decidualization has been widely regarded as an important cause of spontaneous abortion. Generalized decidualization also includes massive infiltration and enrichment of NK cells. However, the underlying mechanism of decidual NK (dNK) cell residence remains largely unknown. Here, we observe that the increased macroautophagy/autophagy of decidual stromal cells (DSCs) during decidualization, facilitates the adhesion and retention of dNK cells during normal pregnancy. Mechanistically, this process is mediated through activation of the MITF-TNFRSF14/HVEM signaling, and further upregulation of multiple adhesion adhesions (e.g. Selectins and ICAMs) in a MMP9-dependent manner. Patients with unexplained spontaneous abortion display insufficient DSC autophagy and dNK cell residence. In addition, poor vascular remodeling of placenta, low implantation number and high ratio of embryo loss are observed in NK cell depletion mice. In therapeutic studies, low doses of rapamycin, a known autophagy inducer that significantly promotes endometrium autophagy and NK cell residence, and improves embryo absorption in spontaneous abortion mice models, which should be dependent on the activation of MITF-TNFRSF14/HVEM-MMP9-adhension molecules axis. This observation reveals novel molecular mechanisms underlying DSCs autophagy-driven dNK cell residence, and provides a potential therapeutic strategy to prevent spontaneous abortion.Abbreviations: ACTA2/αSMA: actin alpha 2, smooth muscle; ATG: autophagy-related; ATG5^over ESC: ATG5-overexpressed ESCs; BTLA: B and T lymphocyte associated; CDH1: cadherin 1; CDH5: cadherin 5; CXCL12: C-X-C motif chemokine ligand 12; dNK: decidual NK; DIC: decidual immune cell; DSC: decidual stromal cell; EOMES: eomesodermin; ESC: endometrial stromal cell; FCGR3A/CD16: Fc fragment of IgG receptor IIIa; HUVEC: human umbilical vein endothelial cell; ICAM: intercellular cell adhesion molecule; ILC: innate lymphoid cell; ITGB1: integrin subunit beta 1; ITGA2: integrin subunit alpha 2; IPA: Ingenuity Pathway Analysis; KIR2DL1: killer cell immunoglobulin like receptor, two Ig domains and long cytoplasmic tail 1; KLRD1/CD94: killer cell lectin like receptor D1; KLRK1/NKG2D: killer cell lectin like receptor K1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; 3-MA: 3-methyladenine; MITF: melanocyte inducing transcription factor; MiT-TFE: microphthalmia family of bHLH-LZ transcription factors; MMP9: matrix metalloproteinase 9; MTOR: mechanistic target of rapamycin kinase; NCAM1/CD56: neural cell adhesion molecule 1; NCR2/NKp44: natural cytotoxicity triggering receptor 2; NK: natural killer; KLRB1/NK1.1: killer cell lectin like receptor B1; NP: normal pregnancy; PBMC: peripheral blood mononuclear cell; PECAM1/CD31: platelet and endothelial cell adhesion molecule 1; pNK: peripheral blood NK; PRF1/Perforin: Perforin 1; PTPRC/CD45: protein tyrosine phosphatase receptor type C; Rapa: rapamycin; rh-TNFSF14/LIGHT: recombinant human TNFSF14/LIGHT; SA: spontaneous abortion; SELE: selectin E; SELP: selectin P; SELL: selectin L; siATG5 DSCs: ATG5-silenced DSCs; siTNFRSF14/HVEM DSCs: TNFRSF14/HVEM-silenced DSCs; TBX21/T-bet: T-box transcription factor 21; SQSTM1/p62: sequestosome 1; TNFRSF14/HVEM: TNF receptor superfamily member 14; TNFSF14/LIGHT: TNF superfamily member 14; uNK: uterine NK; UIC: uterine immune cell; USC: uterine stromal cell; VCAM1: vascular cell adhesion molecule 1; VIM: vimentin.

An autophagic deficit in the uterine vessel microenvironment provokes hyperpermeability through deregulated VEGFA, NOS1, and CTNNB1

The uterus undergoes vascular changes during the reproductive cycle and pregnancy. Steroid hormone deprivation induces macroautophagy/autophagy in major uterine cell types. Herein, we explored the functions of uterine autophagy using the Amhr2-Cre-driven atg7 deletion model. Deletion of Atg7 was confirmed by functional deficit of autophagy in uterine stromal, myometrial, and vascular smooth muscle cells, but not in endothelial cells. atg7^d/d uteri exhibited enhanced stromal edema accompanied by dilation of blood vessels. Ovariectomized atg7^d/d uteri showed decreased expression of endothelial junction-related proteins, such as CTNNB1/beta-catenin, with increased vascular permeability, and increased expression of VEGFA and NOS1. Nitric oxide (NO) was shown to mediate VEGFA-induced vascular permeability by targeting CTNNB1. NO involvement in maintaining endothelial junctional stability in atg7^d/d uteri was confirmed by the reduction in extravasation following treatment with a NOS inhibitor. We also showed that atg7^d/d uterine phenotype improved the fetal weight:placental weight ratio, which is one of the indicators of assessing the status of preeclampsia. We showed that autophagic deficit in the uterine vessel microenvironment provokes hyperpermeability through the deregulation of VEGFA, NOS1, and CTNNB1.Abbreviations: ACTA2: actin, alpha 2, smooth muscle, aortic; Amhr2: anti-Mullerian hormone type 2 receptor; ANGPT1: angiopoietin 1; ATG: autophagy-related; CDH5: cadherin 5; CLDN5: claudin 5; COL1A1: collagen, type I, alpha 1; CSPG4/NG2: chondroitin sulfate proteoglycan 4; CTNNB1: catenin (cadherin associated protein), beta 1; DES: desmin; EDN1: endothelin 1; EDNRB: endothelin receptor type B; F3: coagulation factor III; KDR/FLK1/VEGFR2: kinase insert domain protein receptor; LYVE1: lymphatic vessel endothelial hyaluronan receptor 1; MAP1LC3B: microtubule-associated protein 1 light chain 3 beta; MCAM/CD146: melanoma cell adhesion molecule; MYL2: myosin, light polypeptide 2, regulatory, cardiac, slow; MYLK: myosin, light polypeptide kinase; NOS1/nNOS: nitric oxide synthase 1, neuronal; NOS2/iNOS: nitric oxide synthase 2, inducible; NOS3/eNOS: nitric oxide synthase 3, endothelial cell; OVX: ovariectomy; PECAM1/CD31: platelet/endothelial cell adhesion molecule 1; POSTN: periostin, osteoblast specific factor; SQSTM1: sequestosome 1; TEK/Tie2: TEK receptor tyrosine kinase; TJP1/ZO-1: tight junction protein 1; TUBB1, tubulin, beta 1 class VI; USC: uterine stromal cell; VEGFA: vascular endothelial growth factor A; VSMC: vascular smooth muscle cell.

Autophagy: A Promising Target for Age-related Osteoporosis

Autophagy is a process the primary role of which is to clear up damaged cellular components such as long-lived proteins and organelles, thus participating in the conservation of different cells. Osteoporosis associated with aging is characterized by consistent changes in bone metabolism with suppression of bone formation as well as increased bone resorption. In advanced age, not only bone mass but also bone strength decrease in both sexes, resulting in an increased incidence of fractures. Clinical and animal experiments reveal that age-related bone loss is associated with many factors such as accumulation of autophagy, increased levels of reactive oxygen species, sex hormone deficiency, and high levels of endogenous glucocorticoids. Available basic and clinical studies indicate that age-associated factors can regulate autophagy. Those factors play important roles in bone remodeling and contribute to decreased bone mass and bone strength with aging. In this review, we summarize the mechanisms involved in bone metabolism related to aging and autophagy, supplying a theory for therapeutic targets to rescue bone mass and bone strength in older people.

Endometrial autophagy is essential for embryo implantation during early pregnancy

Embryo implantation is an essential and complex process in mammalian reproduction. However, little evidence has indicated the involvement of autophagy during embryo implantation. To determine the possible role of autophagy in uterine of pregnant mice during the peri-implantation stage, we first examined the expression of autophagy-related markers ATG5 and LC3 on day 4, 5, and 6 of pregnancy (D4, D5, and D6, respectively). Compared with expression on D4, downregulation of the autophagy-related markers was observed on D5 and D6, the days after the embryo attached to the receptivity endometrium. Further examination showed that autophagy-related markers ATG5, ATG12, LC3, cathepsin B, and P62 at the implantation site were significantly decreased when comparing with the inter-implantation site. Fewer number of autophagosomes at the implantation site were also observed by transmission electron microscopy. To confirm the functional role of autophagy during embryo implantation in mice, we administered the autophagy inhibitor 3-methyladenine and chloroquine to mice. After treated with 3-methyladenine, the expression of decidual markers HOXA10 and progesterone receptor were significantly reduced. Furthermore, a reduction in implantation sites and increase in the HOXA10 and PR protein levels were observed in response to chloroquine treatment. In addition, impaired uterine decidualization and dysregulation of the PR and HOXA10 protein levels was observed after autophagy inhibited by 3-methyladenine and chloroquine in in vivo artificial decidualization mouse model. In the last, LC3 and P62 were also observed in normal human proliferative, secretory, and decidua tissues. In conclusion, endometrial autophagy may be essential for embryo implantation, and it may be associated with endometrial decidualization during early pregnancy. KEY MESSAGE: • Autophagy-related markers were significantly decreased at implantation site. • Autophagy inhibition results in abnormal decidualization. • Autophagy is essential for embryo implantation.

The Autophagy Gene Atg16L1 is Necessary for Endometrial Decidualization

Uterine receptivity is critical for establishing and maintaining pregnancy. For the endometrium to become receptive, stromal cells must differentiate into decidual cells capable of secreting factors necessary for embryo survival and placental development. Although there are multiple reports of autophagy induction correlated with endometrial stromal cell (ESC) decidualization, the role of autophagy in decidualization has remained elusive. To determine the role of autophagy in decidualization, we utilized 2 genetic models carrying mutations to the autophagy gene Atg16L1. Although the hypomorphic Atg16L1 mouse was fertile and displayed proper decidualization, conditional knockout in the reproductive tract of female mice reduced fertility by decreasing the implantation rate. In the absence of Atg16L1, ESCs failed to properly decidualize and fewer blastocysts were able to implant. Additionally, small interfering RNA knock down of Atg16L1 was detrimental to the decidualization response of human ESCs. We conclude that Atg16L1 is necessary for decidualization, implantation, and overall fertility in mice. Furthermore, considering its requirement for human endometrial decidualization, these data suggest Atg16L1 may be a potential mediator of implantation success in women.

Autophagy Attenuation Hampers Progesterone Synthesis during the Development of Pregnant Corpus Luteum

Simple Summary

The present study demonstrates that induction of autophagy-related proteins in corpus luteum is regulated by Akt/mTOR signaling and autophagy may exert influences on progesterone production by controlling the pool of lipid droplets in luteal cells during the luteal development of pregnant rats. Furthermore, mitophagy-related proteins were also induced during the initiation of luteal regression in pregnant rats, which may play an essential role in the maintenance of mitochondrial homeostasis. These findings will shed light on the role of autophagy during the luteal development of pregnant ovaries in vivo in mammals.

Abstract

The contribution of autophagy to catabolic balance has been well-established in various types of cells, whereas the involvement of autophagy in progesterone synthesis during rat pregnancy still remains unknown. Therefore, the present study was designed to evaluate the role of autophagy in progesterone production during the luteal development of pregnant rats. The results showed autophagy-related proteins was maintained at a low level on day 10 after pregnancy, significantly induced on day 16 and subsided to a relative low level on day 21, which was consistent with the changes of serum progesterone levels. The findings further indicated the contribution of autophagy to progesterone production was regulated by inactivation of Akt/mTOR signaling during the luteal development of pregnant rats in in vivo and in vitro experiments. Further investigations revealed autophagy may be involved in the surge of progesterone production in pregnant rats, as inhibition of autophagy by 3-MA compromised serum progesterone levels. Furthermore, 3-MA treatment also leveled down the number of lipid droplets in luteal cells, implying that autophagy may affect the production of progesterone by manipulating the formation of lipid droplets in luteal cells. In addition, the results suggested that mitophagy was mobilized during the primary stage of luteolysis and inhibition of autophagy promoted the increase of redundant mitochondrial and cytoplasmic cytochrome C in luteal cells of pregnant rats. Taken together, the present study indicated that autophagy-related proteins were induced by the inactivation of Akt/mTOR signaling and then contributed to the progesterone production possibly by affecting the formation of intracellular lipid droplets during the luteal development of pregnant rats. To our knowledge, this will provide a new insight into the important mechanism of autophagy regulating progesterone production in ovaries of pregnant mammals.

Effect of Ovariectomy and Ovarian Hormone Administration on Hepatic Autophagy in Female Rats

Autophagy is a major intracellular proteolytic process that contributes to the maintenance of protein homeostasis. Recent studies reported the induction of autophagy in the uterus and proximal tibias of ovariectomized (OVX) rodents, which was blocked by the injection of ovarian hormones. However, whether OVX and ovarian hormone treatment can regulate autophagy in the liver has not been clarified. Recently, it was revealed that autophagy is closely involved in hepatic lipid metabolism. The purpose of this study was to investigate the influence of OVX on autophagy in the rat liver as a first step to clarify the relationship between hepatic fat accumulation and the change in autophagy caused by OVX. We found that hepatic autophagy tended to be lower in OVX rats than in sham-operated rats. In addition, hepatic autophagy in OVX rats was induced by short-term exposure to ovarian hormones, especially progesterone. This study suggests that autophagy in the rat liver is suppressed by OVX and activated by progesterone. However, the autophagy-promoting effect of β-estradiol was not clarified.

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.

Rapamycin Alleviates Hormone Imbalance-Induced Chronic Nonbacterial Inflammation in Rat Prostate Through Activating Autophagy via the mTOR/ULK1/ATG13 Signaling Pathway

Chronic prostatitis (CP) is a clinically common disease with high morbidity. It affects the patients' quality of life (QoL) as well as physical and mental health seriously due to the recurring symptoms of lower urinary tract and genitalia. As the opinions about the etiology of CP are still not uniform, it is very difficult to be treated or even cured. Autophagy is a highly conserved physiological function which is widely found in eukaryotic cells. In general, cells maintain a certain level of autophagy under physiological conditions, and the basal level of autophagy can be regulated by a variety of autophagy-related genes under stress such as hunger, infection, trauma, and other circumstances. Therefore, the main purpose of this study is to investigate the role of autophagy in chronic nonbacterial prostatitis (CNP, also called CP). In this paper, we established the CNP model via hypodermic injection of 17β-estradiol and subsequently abdominal rapamycin (a common autophagy inducer) treatment based on castrated rats. Then, the expression of nuclear factor-κB (NF-κB), interleukin-1β (IL-1β), and autophagy-related markers as well as autophagosome formation in prostate tissues, peripheral blood mononuclear cells (PBMCs), and serum of rats were evaluated respectively. In addition to some histological changes in the prostate tissues, we found the levels of NF-κB and IL-1β were significantly increased in the model group, along with significantly suppressed autophagy, whereas rapamycin could reverse these effects which involved in the mTOR/ULK1/ATG13 signaling pathway. In conclusion, our results suggested that rapamycin could ameliorate hormone imbalance-induced CNP by activating autophagy.

Rapamycin‑induced autophagy attenuates hormone‑imbalance‑induced chronic non‑bacterial prostatitis in rats via the inhibition of NLRP3 inflammasome‑mediated inflammation

Chronic non-bacterial prostatitis (CNBP) is a common urinary disease and no standard treatments are available at present. Although autophagy serves an important role in a variety of chronic diseases, its role in CNBP is yet to be fully elucidated. Therefore, the present study aimed to investigate the effects of rapamycin-induced autophagy on CNBP by establishing a rat model. In the present study, a total of 30 male Sprague-Dawley rats were randomly divided into three groups (n=10 per group): i) Control, in which rats underwent a sham operation; ii) the model (CNBP), in which rats were castrated and administered 17β-estradiol (0.25 mg/kg via subcutaneous injection) for 30 consecutive days; and iii) rapamycin treatment, in which rats were employed in accordance with the CNBP model, but also received a daily intraperitoneal injection of rapamycin (1 mg/kg) from the 16th day post-surgery for 15 days. Alterations in histology and the levels of autophagy-associated markers, and components of the NLRP3 inflammasome, were measured in the prostate tissues of the rats. The levels of molecules located further downstream of the NLRP3 inflammasome pathway, including interleukin (IL)-1β and IL-18, were also measured. The results demonstrated that, compared with the control group, increased infiltration levels of inflammatory cells and glandular epithelial degeneration were observed in the prostate tissues of rats with CNBP. Furthermore, a significant increase in the concentration of IL-1β and IL-18 in the serum, as well as the increased expression levels of NLRP3, ASC and caspase-1 in prostate tissues were also observed. In addition, reductions in the number of autophagosomes and the expression levels of autophagy-associated, including microtubule-associated protein 1 light chain 3β (LC3B) and Beclin 1, were also detected in the CNBP group; however, treatment with rapamycin reversed these effects. Collectively, the findings of the present study indicated that the NLRP3 inflammasome-mediated inflammatory response was activated by a hormonal imbalance in the prostate glands of rats; however, these effects may be suppressed via rapamycin-induced autophagy.

Involvement of interferon-tau in the induction of apoptotic, pyroptotic, and autophagic cell death-related signaling pathways in the bovine uterine endometrium during early pregnancy

Interferon-tau (IFNT), a type I interferon (IFN), is known as pregnancy recognition signaling molecule secreted from the ruminant conceptus during the preimplantation period. Type I IFNs, such as IFN-alpha and IFN-beta, are known to activate cell-death pathways as well as induce apoptosis. In cows, induction of apoptosis with DNA fragmentation is induced by IFNT in cultured bovine endometrial epithelial cells. However, the status of cell-death pathways in the bovine endometrium during the preimplantation period still remains unclear. In the present study, we investigated the different cell-death pathways, including apoptosis, pyroptosis, and autophagy, in uterine tissue obtained from pregnant cows and in vitro cultured endometrial epithelial cells with IFNT stimulation. The expression of CASP7, 8, and FADD (apoptosis-related genes) was significantly higher in pregnant day 18 uterine tissue in comparison to non-pregnant day 18 tissue. The expression of CASP4, 11, and NLRP3 (pyroptosis-related genes) was significantly higher in the pregnant uterus in comparison to non-pregnant uterus. In contrast, autophagy-related genes were not affected by pregnancy. We also investigated the effect of IFNT on the expression of cell-death pathway-related genes, as well as DNA fragmentation in cultured endometrial epithelial cells. Similar to its effects in pregnant uterine tissue, IFNT affected the increase of apoptosis-related (CASP8) and pyroptosis-related genes (CASP11), but did not affect autophagy-related gene expression. IFNT also increased γH2AX-positive cells, which is a marker of DNA fragmentation. These results suggest that apoptosis- and pyroptosis-related genes are induced by IFNT in the pregnant bovine endometrial epithelial cells.

Sex Differences in Autophagy Contribute to Female Vulnerability in Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia, with over 5. 4 million cases in the US alone (Alzheimer's Association, 2016). Clinically, AD is defined by the presence of plaques composed of Aβ and neurofibrillary pathology composed of the microtubule associated protein tau. Another key feature is the dysregulation of autophagy at key steps in the pathway. In AD, disrupted autophagy contributes to disease progression through the failure to clear pathological protein aggregates, insulin resistance, and its role in the synthesis of Aβ. Like many psychiatric and neurodegenerative diseases, the risk of developing AD, and disease course are dependent on the sex of the patient. One potential mechanism through which these differences occur, is the effects of sex hormones on autophagy. In women, the loss of hormones with menopause presents both a risk factor for developing AD, and an obvious example of where sex differences in AD can stem from. However, because AD pathology can begin decades before menopause, this does not provide the full answer. We propose that sex-based differences in autophagy regulation during the lifespan contribute to the increased risk of AD, and greater severity of pathology seen in women.

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.

Effects of ovarian hormone loss on neuritic plaques and autophagic flux in the brains of adult female APP/PS1 double-transgenic mice

Epidemiologic studies have demonstrated that women account for two-thirds of Alzheimer’s disease (AD) cases, for which the decline in circulating gonadal hormone is considered to be one of the major risk factors. In addition, ovarian hormone deficiency may affect β-amyloid (Aβ) deposition, which has a close relationship with autophagic flux. In this study, we investigated the impact of short-term or long-term ovarian hormone deprivation on two mouse models, the non-transgenic (wild-type) and the APP/PS1 double-transgenic AD (2×TgAD) model. Autophagy-related proteins (Beclin1, LC3, and p62) and lysosome-related proteins were detected to evaluate Aβ deposition and autophagy. Our results showed that in the group with short-term depletion of ovarian hormones by ovariectomy (ovx), Beclin1, Cathepsin B (Cath-B), and LAMP1 levels were significantly decreased, while the levels of LC3-II and p62 were increased. In the long-term group, however, there was a sharp decline in Beclin1, LC3-II, Cath-B, and LAMP1 expression but not in p62 expression which is increased. It is worthwhile to note that the occurrence of neuritic plaque-induced ovarian hormone loss increased both the Aβ level and neuritic plaque deposition in 2×TgAD mice. Therefore, autophagy may play an important role in the pathogenesis of female AD, which is also expected to help post-menopausal patients with AD.

Sex-specific autophagy modulation in osteoblastic lineage: a critical function to counteract bone loss in female

Age-related bone loss is associated with an increased oxidative stress which is worsened by estrogen fall during menauposis. This observation has drawn attention to autophagy, a major cellular catabolic process, able to alleviate oxidative stress in osteoblasts (OB) and osteocytes (OST), two key bone cell types. Moreover, an autophagy decline can be associated with aging, suggesting that an age-related autophagy deficiency in OB and/or OST could contribute to skeletal aging and osteoporosis onset.

In the present work, autophagy activity was analyzed in OST and OB in male and female mice according to their age and hormonal status. In OST, autophagy decreases with aging in both sexes. In OB, although a 95% decrease in autophagy is observed in OB derived from old females, this activity remains unchanged in males. In addition, while ovariectomy has no effect on OB autophagy levels, orchidectomy appears to stimulate this process. An inverse correlation between autophagy and the oxidative stress level was observed in OB derived from males or females. Finally, using OB-specific autophagy-deficient mice, we showed that autophagy deficiency aggravates the bone loss associated with aging and estrogen deprivation.

Taken together, our data indicate that autophagic modulation in bone cells differs according to sex and cell type. The lowering of autophagy in female OB, which is associated with an increased oxidative stress, could play a role in osteoporosis pathophysiology and suggests that autophagy could be a new therapeutic target for osteoporosis in women.

Mechanisms of autophagy induction by sex steroids in bovine mammary epithelial cells

In dairy cattle, mammary gland involution serves to remodel the secretory tissue and occurs in a period of overlap between mammogenic stimulation caused by the next developing pregnancy and tissue regression induced by milk stasis. At this time, high concentrations of 17β-oestradiol (E2) and progesterone (P4) support the regeneration of the mammary tissue, as well as enhance autophagy, a cellular process induced in response to stressful conditions for energy generation and homeostasis maintenance. This study aimed to elucidate the mechanisms of autophagy induction by E2 and P4 using an in vitro model of involution based on 20-fold reduction of FBS content (from 10% to 0.5%) in the culture medium of BME-UV1 bovine mammary epithelial cells (MECs). Real-time RT-PCR, Western blot and EMSA analyses demonstrated that addition of E2 and P4 caused a genomic effect in BME-UV1 cells, stimulating the expression of autophagy-related genes (ATGs): BECN1, ATG5, LC3B and their corresponding proteins. Furthermore, knockdown of oestrogen receptor (ERα) and experiments with the use of oestrogen and progesterone antagonists (4-hydroxytamoxifen and RU-486, respectively) demonstrated that the observed genomic effect is mediated by steroid receptors. Finally, both steroids were shown to form complexes with beclin1 and regulate Bcl-2 phosphorylation, indicating that an indirect, non-genomic effect of E2 and P4 may also contribute to autophagy induction in bovine MECs.

PI3K/AKT/mTOR pathway promotes progestin resistance in endometrial cancer cells by inhibition of autophagy

Endometrial cancer (EC) is now one of the most common malignant tumors in young women. In all, 90% of young patients with EC have a high expression of progesterone recep tor, can be treated with progestin, and have very good prognosis. However, some of the young EC patients are resistant to progestin, the mechanism of which is unclear. To illuminate the mechanism by which endometrial cells acquire progestin resistance, we treated Ishikawa cells by slowly increasing dosage of progestin and established a progestin-resistant cell subline. We show here that progesterone resistant cells acquire increased proliferation rate and interestingly decreased autophagy. To uncover the mechanism by which cells increase proliferation and bypass autophagy, we found higher activation of phosphatidylinositol 3-kinase/AKT/mTOR signaling pathway was necessary to this malignant acquirement by RNAi technique. Further, we elucidated that activation of mTOR was sufficient and necessary for progestin resistance. RAD001, an inhibitor of mTOR, decreased phosphorylation of mTOR and inhibited proliferation of progestin-resistant cancer cells by promoting autophagy. Thus, our results indicated that mTOR can be a target to treat the progestin-resistant EC.

Autophagy regulation of physiological and pathological processes in the female reproductive tract

Autophagy is a ubiquitous cell recycling pathway that delivers cytoplasmic constituents to the lysosome and is essential for normal cellular function. Autophagic activity is up-regulated under physiological conditions as well as stressful conditions such as nutrient deprivation, oxidative stress, hypoxia, inflammation, and infection. Thus, it is essential to regard the functional importance of the pathway and its components in a given tissue context. Here we review what is known about the involvement of autophagy process during physiological processes in the female reproductive tract and in pregnancy from preimplantation to oocyte function to placental development, parturition, and postpartum remodeling of the uterus; as well as in pathological and adverse events during these processes.

Autophagic regulation in steroid hormone-responsive systems

Two female sex steroid hormones, estrogen and progesterone, are crucial regulators of many physiological functions of reproductive organs. These two hormones are versatile factors linking growth, differentiation, metabolism, and death of cells in the uterus. In recent years, it has become evident that autophagy is involved in the effects of estrogen and progesterone on various cellular events in reproductive organs. Autophagy is the self-eating catabolic process which is linked to cell survival and death in many contexts. In this review, we focus on the new findings concerning the regulation of autophagic response by sex steroid hormones in responsive target organs. We also attempt to further expand our insight into intracellular signaling mediators governing this regulation.

Vitrification, in vitro fertilization, and development of Atg7 deficient mouse oocytes

Objective

Autophagy contributes to the clearance and recycling of macromolecules and organelles in response to stress. We previously reported that vitrified mouse oocytes show acute increases in autophagy during warming. Herein, we investigate the potential role of Atg7 in oocyte vitrification by using an oocyte-specific deletion model of the Atg7 gene, a crucial upstream gene in the autophagic pathway.

Methods

Oocyte-specific Atg7 deficient mice were generated by crossing Atg7 floxed mice and Zp3-Cre transgenic mice. The oocytes were vitrified-warmed and then subjected to in vitro fertilization and development. The rates of survival, fertilization, and development were assessed in the Atg7 deficient oocytes in comparison with the wildtype oocytes. Light chain 3 (LC3) immunofluorescence staining was performed to determine whether this method effectively evaluates the autophagy status of oocytes.

Results

The survival rate of vitrified-warmed Atg7^f/f;Zp3-Cre (Atg7^d/d) metaphase II (MII) oocytes was not significantly different from that of the wildtype (Atg7^f/f) oocytes. Fertilization and development in the Atg7^d/d oocytes were significantly lower than the Atg7^f/f oocytes, comparable to the Atg5^d/d oocytes previously described. Notably, the developmental rate improved slightly in vitrified-warmed Atg7^d/d MII oocytes when compared to fresh Atg7^d/d oocytes. LC3 immunofluorescence staining showed that this method can be reliably used to assess autophagic activation in oocytes.

Conclusion

We confirmed that the LC3-positive signal is nearly absent in Atg7^d/d oocytes. While autophagy is induced during the warming process after vitrification of MII oocytes, the Atg7 gene is not essential for survival of vitrified-warmed oocytes. Thus, induction of autophagy during warming of vitrified MII oocytes seems to be a natural response to manage cold or other cellular stresses.

Rapamycin Influences the Efficiency of In vitro Fertilization and Development in the Mouse: A Role for Autophagic Activation

The mammalian target of rapamycin (mTOR) regulates cellular processes such as cell growth, metabolism, transcription, translation, and autophagy. Rapamycin is a selective inhibitor of mTOR, and induces autophagy in various systems. Autophagy contributes to clearance and recycling of macromolecules and organelles in response to stress. We previously reported that vitrified-warmed mouse oocytes show acute increases in autophagy during warming, and suggested that it is a natural response to cold stress. In this follow-up study, we examined whether the modulation of autophagy influences survival, fertilization, and developmental rates of vitrified-warmed mouse oocytes. We used rapamycin to enhance autophagy in metaphase II (MII) oocytes before and after vitrification. The oocytes were then subjected to in vitro fertilization (IVF). The fertilization and developmental rates of vitrified-warmed oocytes after rapamycin treatment were significantly lower than those for control groups. Modulation of autophagy with rapamycin treatment shows that rapamycin-induced autophagy exerts a negative influence on fertilization and development of vitrified-warmed oocytes.

Increased activity of osteocyte autophagy in ovariectomized rats and its correlation with oxidative stress status and bone loss

OBJECTIVES

The objectives of the present study were to investigate ovariectomy on autophagy level in the bone and to examine whether autophagy level is associated with bone loss and oxidative stress status.

METHODS

36 female Sprague-Dawley rats were randomly divided into sham-operated (Sham), and ovariectomized (OVX) rats treated either with vehicle or 17-β-estradiol. At the end of the six-week treatment, bone mineral density (BMD) and bone micro-architecture in proximal tibias were assessed by micro-CT. Serum 17β-estradiol (E2) level were measured. Total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity in proximal tibia was also determined. The osteocyte autophagy in proximal tibias was detected respectively by Transmission Electron Microscopy (TEM), immunofluorescent histochemistry (IH), realtime-PCR and Western blot. In addition, the spearman correlation between bone mass, oxidative stress status, serum E2 and autophagy were analyzed.

RESULTS

Ovariectomy increased Atg5, LC3, and Beclin1 mRNA and proteins expressions while decreased p62 expression. Ovariectomy also declined the activities of T-AOC, CAT, and SOD. Treatment with E2 prevented the reduction in bone mass as well as restored the autophagy level. Furthermore, LC3-II expression was inversely correlated with T-AOC, CAT, and SOD activities. A significant inverse correlation between LC3-II expression and BV/TV, Tb.N, BMD in proximal tibias was found.

CONCLUSIONS

Ovariectomy induced oxidative stress, autophagy and bone loss. Autophagy of osteocyte was inversely correlated with oxidative stress status and bone loss.