Exposure to polystyrene nanoplastics induces hepatotoxicity involving NRF2-NLRP3 signaling pathway in mice.

Nanoplastic contamination has been of intense concern by virtue of the potential threat to human and ecosystem health. Animal experiments have indicated that exposure to nanoplastics (NPs) can deposit in the liver and contribute to hepatic injury. To explore the mechanisms of hepatotoxicity induced by polystyrene-NPs (PS-NPs), mice and AML-12 hepatocytes were exposed to different dosages of 20 nm PS-NPs in this study. The results illustrated that in vitro and in vivo exposure to PS-NPs triggered excessive production of reactive oxygen species and repressed nuclear factor erythroid-derived 2-like 2 (NRF2) antioxidant pathway and its downstream antioxidase expression, thus leading to hepatic oxidative stress. Moreover, PS-NPs elevated the levels of NLRP3, IL-1ß and caspase-1 expression, along with an activation of NF-κB, suggesting that PS-NPs induced hepatocellular inflammatory injury. Nevertheless, the activaton of NRF2 signaling by tert-butylhydroquinone mitigated PS-NPs-caused oxidative stress and inflammation, and inbihited NLRP3 and caspase-1 expression. Conversely, the rescuing effect of NRF2 signal activation was dramatically supressed by treatment with NRF2 inhibitor brusatol. In summary, our results demonstrated that NRF2-NLRP3 pathway is involved in PS-NPs-aroused hepatotoxicity, and the activation of NRF2 signaling can protect against PS-NPs-evoked liver injury. These results provide novel insights into the hepatotoxicity elicited by NPs exposure.

Transcriptomic responses of cumulus granulosa cells to SARS-CoV-2 infection during controlled ovarian stimulation.

Cumulus granulosa cells (CGCs) play a crucial role in follicular development, but so far, no research has explored the impact of SARS-CoV-2 infection on ovarian function from the perspective of CGCs. In the present study, we compared the cycle outcomes between infected and uninfected female patients undergoing controlled ovarian stimulation, performed bulk RNA-sequencing of collected CGCs, and used bioinformatic methods to explore transcriptomic changes. The results showed that women with SARS-CoV-2 infection during stimulation had significantly lower number of oocytes retrieved and follicle-oocyte index, while subsequent fertilization and embryo development were similar. CGCs were not directly infected by SARS-CoV-2, but exhibited dramatic differences in gene expression (156 up-regulated and 65 down-regulated). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses demonstrated a high enrichment in antiviral, immune and inflammatory responses with necroptosis. In addition, the pathways related to telomere organization and double strand break repair were significantly affected by infection in gene set enrichment analysis. Further weighted gene co-expression network analysis identified a key module associated with ovarian response traits, which was mainly enriched as a decrease of leukocyte chemotaxis and migration in CGCs. For the first time, our study describes how SARS-CoV-2 infection indirectly affects CGCs at the transcriptional level, which may impair oocyte-CGC crosstalk and consequently lead to poor ovarian response during fertility treatment.

Gestational exposure to bisphenol AF causes endocrine disorder of corpus luteum by altering ovarian SIRT-1/Nrf2/NF-kB expressions and macrophage proangiogenic function in mice.

Bisphenol AF (BPAF) is extensively used in industrial production as an emerging substitute for the earlier-used bisphenol A (BPA). Studies have found that BPAF had stronger estrogenic activities than BPA. However, the effects of BPAF on the luteal function of pregnancy and its possible mechanisms are largely unknown. In this study, pregnant mice were orally administered 3.0 and 30 mg/kg/day of BPAF from gestational day (GD) 1 to 8, and samples were collected on GD 8 and GD 19. Results showed that maternal exposure to BPAF impaired embryo implantation and reduced ovarian weight, and interfered with steroid hormone secretion, and decreased the numbers and areas of corpus luteum. BPAF treatment significantly down-regulated expression levels of ovarian Star, Cyp11a, Hsd3b1, and Cyp19a1 mRNA and CYP19a1 and ERα proteins. BPAF also disrupted markers of redox/inflammation key, including silent information regulator of transcript-1 (SIRT-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor kappa-B (NF-ĸB) expressions along with reduced ovarian antioxidant (CAT and SOD) capacity, enhanced oxidant (H2O2 and MDA) and inflammatory factor (Il6 and Tnfa) activities. Furthermore, BPAF exposure inhibited macrophages with a pro-angiogenic phenotype that specifically expressed TIE-2, accompanied by inhibition of angiogenic factors (HIF1a, VEGFA, and Angpt1) and promotion of anti-angiogenic factor Ang-2 to suppress luteal angiogenesis. In addition, BPAF administration also induced luteolysis and apoptosis by up-regulation of COX-2, BAX/BCL-2, and Cleaved-Caspase-3 protein. Collectively, our current data demonstrated that gestational exposure to BPAF caused luteal endocrine disorder by altering ovarian SIRT-1/Nrf2/NF-kB expressions and macrophage proangiogenic function in mice.

Regulatory mechanism and research progress of ferroptosis in obstetrical and gynecological diseases.

Ferroptosis is a novel type of regulated cell death driven by iron-dependent lipid peroxidation, which is distinguished from traditional types of programmed cell death, such as apoptosis, proptosis and necrosis et al. Impaired iron homeostasis, lipid peroxidation and antioxidants depletion are three hallmarks of ferroptosis. Over the past years, emerging studies support the notion that ferroptosis might be involved in the pathology of obstetrical and gynecological diseases, including preeclampsia (PE), endometriosis (EMs) and polycystic ovarian syndrome (PCOS). In the PE condition, the high sensitivity of trophoblasts towards ferroptosis has been found to potentially link to inflammation, suboptimal vascular remodeling and aberrant hemodynamics, which are three prominent pathophysiological features of PE. As for EMs, compromised ferroptosis of endometrial cells was associated with the formation ectopic lesions, whereas in the nearby lesions, the presence of ferroptosis was suggested to promote the progression of EMs, contributing to the relative clinical manifestations. Ferroptosis has been implicated a crucial role in the initiation of ovarian follicular atresia, which might help to manage ovulation in PCOS patients. Taken together, this review explored the basis of ferroptosis mechanisms and comprehensively summarized the latest discovery of roles of ferroptosis on PE, EMs and PCOS, gaining a deeper insight into the pathogenesis of these obstetrical and gynecological diseases and investigation of novel therapeutic interventions.

Exposure to nanoplastics induces mitochondrial impairment and cytomembrane destruction in Leydig cells.

Plastic particle pollution poses an emerging threat to ecological and human health. Laboratory animal studies have illustrated that nano-sized plastics can accumulate in the testis and cause testosterone deficiency and spermatogenic impairment. In this study, TM3 mouse Leydig cells were in vitro exposed to polystyrene nanoparticles (PS-NPs, size 20 nm) at dosages of 50, 100 and 150 µg/mL to investigate their cytotoxicity. Our results demonstrated that PS-NPs can be internalized into TM3 Leydig cells and led to a concentration-dependent decline in cell viability. Furthermore, PS-NPs stimulation amplified ROS generation and initiated cellular oxidative stress and apoptosis. Moreover, PS-NPs treatment affected the mitochondrial DNA copy number and collapsed the mitochondrial membrane potential, accompanied by a disrupted energy metabolism. The cells exposed to PS-NPs also displayed a down-regulated expression of steroidogenesis-related genes StAR, P450scc and 17ß-HSD, along with a decrease in testosterone secretion. In addition, treatment with PS-NPs destructed plasma membrane integrity, as presented by increase in lactate dehydrogenase release and depolarization of cell membrane potential. In summary, these data indicated that exposure to PS-NPs in vitro produced cytotoxic effect on Leydig cells by inducing oxidative injury, mitochondrial impairment, apoptosis, and cytomembrane destruction. Our results provide new insights into male reproductive toxicity caused by NPs.

Maternal exposure to a glyphosate-based herbicide impairs placental development through endoplasmic reticulum stress in mice.

Glyphosate-based herbicides (GBHs) are the most widely used agrochemicals worldwide, increasing the risk of their occurrence in the environment. This study aimed to explore effects and mechanisms of GBH exposure on placental development in vivo during pregnancy in mice. Pregnant mice received GBH by gavage at 0, 5, and 50 mg⋅kg-1⋅day-1 doses from gestational day (GD) 1 to GD 13 and were sacrificed on GD 13 or GD19. Our data indicated that GBH administration significantly increased the number of resorbed fetuses, reduced the weight of fetuses and placentas, and inhibited placental growth, as evident from decreased placental total area and spongiotrophoblast area on GD 19. GBH treatment also inhibited proliferation and induced apoptosis of placenta via upregulation of Bax, cleaved caspase-3 and -12 expression, and downregulation of B cell lymphoma (Bcl)-2 expression. Further study showed that GBH exposure significantly increased expression levels of glucose-regulated protein 78 (GRP78), protein kinase RNA-like endoplasmic reticulum kinase (PERK), and C/EBP homologous protein (CHOP) mRNAs and proteins and triggered oxidative stress in placenta on GD 13 and GD 19. In conclusion, our findings suggest that maternal exposure to GBH can impair placental development through the endoplasmic reticulum stress-mediated activation of GRP78/PERK/CHOP signaling pathway in mice.

Bisphenol S exposure induces cytotoxicity in mouse Leydig cells.

Bisphenol S (BPS), an increasingly used alternative to bisphenol A, has been linked to testosterone deficiency and male reproductive dysfunction in laboratory animals. This study aimed to examine the cytotoxicity of BPS exposure to Leydig cells and to investigate its possible mechanisms. After treatment with BPS (100, 200 and 400 µM) for 48 h in vitro, TM3 mouse Leydig cells exhibited a dose-dependent decrease in the viability. Furthermore, BPS challenge triggered oxidative stress manifested by compromised activities of superoxide dismutase and catalase with exaggerated formation of reactive oxygen species. Especially, BPS exposure resulted in augmented mitochondrial permeability transition pore opening, dissipated mitochondrial membrane potential and reduced ATP generation, along with an altered energy metabolism. Moreover, BPS stimulation enhanced BAX expression and caspase-3 activity and inhibited BCL-2 expression. In addition, BPS-treated TM3 cells showed an accumulation of autophagic vacuoles, together with increased Beclin1 and P62 expression and elevated LC3B-II/LC3B-I ratio. These results demonstrated that in vitro exposure to BPS exerted cytotoxicity to TM3 Leydig cells through inducing oxidative stress, mitochondrial impairment, autophagic disturbance and apoptosis.

Maternal exposure to polystyrene nanoplastics during gestation and lactation induces hepatic and testicular toxicity in male mouse offspring.

Nanoplastics have raised considerable concerns since their ubiquity in the environment and potential hazard to health. It has been proven that polystyrene nanoparticles (PS-NPs) can be maternally transferred to the offspring. In this study, mice were exposed gestationally and lactationally to PS-NPs (size 100 nm) at different doses (0.1, 1 and 10 mg/L) to investigate the trans-generational poisonousness. Our data illustrated that maternal PS-NPs exposure in pregnancy and lactation resulted in a decline in birth and postnatal body weight in offspring mice. Furthermore, high-dose PS-NPs reduced liver weight, triggered oxidative stress, caused inflammatory cell infiltration, up-regulated proinflammatory cytokine expression, and disturbed glycometabolism in the liver of male offspring mice. In addition, pre- and postnatal PS-NPs exposure diminished testis weight, disrupted seminiferous epithelium and decreased sperm count in mouse offspring. Moreover, PS-NPs induced testicular oxidative injury, as presented by increased malondialdehyde generation and altered superoxide dismutase and catalase activities in the testis of offspring mice. These findings declared that maternal exposure to PS-NPs in pregnancy and lactation can cause hepatic and testicular toxicity in male mouse pups, which put forward new understanding into the detrimental effects of nanoplastics on mammalian offspring.

Gestational exposure to acrylamide suppresses luteal endocrine function through dysregulation of ovarian angiogenesis, oxidative stress and apoptosis in mice.

The discovery of acrylamide in various carbohydrate-rich foods cooked at high temperatures has attracted public health concerns. This study aimed to elucidate the effects and mechanisms additional with acrylamide exposure on the luteal function in vivo during early- and mid-pregnancy. Mice were fed with different dosages of acrylamide (0, 10 and 50 mg/kg/day) by gavage from gestational days (GD) 3 to GD 8 or GD 13. The results indicated that acrylamide exposure significantly decreased levels of serum progesterone and estradiol, and the numbers and relative areas of ovarian corpora lutea. The expression levels of Hsd3b1, Cyp11a1 and Star mRNA markedly reduced in acrylamide-treated ovaries. Furthermore, acrylamide exposure obviously suppressed the activities of catalase and superoxide dismutase, but increased the levels of H2O2 and malondialdehyde. Additionally, acrylamide treatment significantly inhibited luteal angiogenesis and induced the apoptosis of ovarian cells by up-regulation of P53 and Bax protein and down-regulation of Bcl-2 protein. Thus, our results showed that gestational exposure to acrylamide significantly inhibited luteal endocrine function via dysregulation of ovarian angiogenesis, oxidative stress and apoptosis in vivo.

Maternal exposure to tributyltin during early gestation increases adverse pregnancy outcomes by impairing placental development.

Tributyltin (TBT) is a persistent organotin pollutant widely used as agricultural and wood biocides, exhibiting well-documented toxicity to reproductive functions in aquatic organisms. However, the effect of TBT on early pregnancy and placental development has been rarely studied in mice. Pregnant mice were fed with 0, 0.2, and 2 mg/kg/day TBT from gravid day 1 to day 8 or 13. TBT exposure led to an increase in the number of resorbed embryo and a reduction in the weight of fetus at gestational days 13. Further study showed that TBT significantly decreased placental weight and area, lowered laminin immunoreactivity and the expressions of placental development-related molecules including Fra1, Eomes, Hand1, and Ascl2. Moreover, TBT treatment markedly inhibited the placental proliferation and induced up-regulation of p53 and cleaved caspase-3 proteins, and down-regulation of Bcl-2 protein. In addition, TBT administration increased levels of malondialdehyde and H2 O2 and decreased activities of catalase and superoxide dismutase. Collectively, these results suggested TBT-induced adverse pregnancy outcomes during early pregnancy might be involved in developmental disorders of the placenta via dysregulation of key molecules, proliferation, apoptosis, and oxidative stress.

Caloric restriction in female reproduction: is it beneficial or detrimental?

Caloric restriction (CR), an energy-restricted intervention with undernutrition instead of malnutrition, is widely known to prolong lifespan and protect against the age-related deteriorations. Recently it is found that CR significantly affects female reproduction via hypothalamic (corticotropin releasing hormone, neuropeptide Y, agouti-related peptide) and peripheral (leptin, ghrelin, insulin, insulin-like growth factor) mediators, which can regulate the energy homeostasis. Although CR reduces the fertility in female mammals, it exerts positive effects like preserving reproductive capacity. In this review, we aim to discuss the comprehensive effects of CR on the central hypothalamus-pituitary-gonad axis and peripheral ovary and uterus. In addition, we emphasize the influence of CR during pregnancy and highlight the relationship between CR and reproductive-associated diseases. Fully understanding and analyzing the effects of CR on the female reproduction could provide better strategies for the management and prevention of female reproductive dysfunctions.

Reduced neuropathy target esterase in pre-eclampsia suppresses tube formation of HUVECs via dysregulation of phospholipid metabolism.

Recently, studies have shown that neuropathy target esterase (NTE) is essential to placental and normal blood vessel development. However, whether it is involved in abnormal placenta angiogenesis of pre-eclampsia remains unknown. Thus, our aim was to observe the expression of NTE in pre-eclamptic placentas and its effects and mechanism of NTE on the migration and the tube formation of human umbilical vein endothelial cells (HUVECs). Immunohistochemical staining showed that the NTE protein was intensely located in blood vessels of the normal pregnant placenta. However, western blot revealed that the expression level of NTE protein was significantly reduced in pre-eclamptic placenta. The results indicated that overexpression of NTE significantly promoted the migration and the tube formation of HUVECs compared with those of the control and scramble short hairpin RNA (shRNA) group. Conversely, NTE shRNA obviously inhibited the migration and the tube formation of HUVECs. Additionally, chromatography assay evidenced that NTE overexpression significantly reduced the level of phosphatidylcholine (PC) of HUVECs, but NTE shRNA obviously increased the level of PC of HUVECs. Furthermore, exogenous PC and lysophosphatidylcholine (LPC) significantly inhibited the tube formation of HUVECs in a dose-dependent manner. Collectively, our results suggest that reduced NTE in placenta may contribute to abnormal placenta angiogenesis of pre-eclampsia via the dysregulation of PC and LPC metabolism.

Emerging roles of APLN and APELA in the physiology and pathology of the female reproductive system.

APLN, APELA and their common receptor APLNR (composing the apelinergic axis) have been described in various species with extensive body distribution and multiple physiological functions. Recent studies have witnessed emerging intracellular cascades triggered by APLN and APELA which play crucial roles in female reproductive organs, including hypothalamus-pituitary-gonadal axis, ovary, oviduct, uterus and placenta. However, a comprehensive summary of APLN and APELA roles in physiology and pathology of female reproductive system has not been reported to date. In this review, we aim to concentrate on the general characteristics of APLN and APELA, as well as their specific physiological roles in female reproductive system. Meanwhile, the pathological contexts of apelinergic axis dysregulation in the obstetrics and gynecology are also summarized here, suggesting its potential prospect as a diagnostic biomarker and/or therapeutic intervention in the polycystic ovary syndrome, ovarian cancer, preeclampsia and gestational diabetes mellitus.

Perfluorooctanoic acid induces cytotoxicity in spermatogonial GC-1 cells.

Perfluorooctane acid (PFOA), a typical perfluorinated chemical, has been suggested to interfere with male reproductive function. In this study, mouse spermatogonial GC-1 cells were in vitro treated with PFOA (250, 500 or 750 µM) for 24 h to investigate the cytotoxicity of PFOA and its underlying mechanisms. Our results indicated that exposure to intermediate and high doses of PFOA suppressed the viability of GC-1 cells in a concentration-dependent manner. Furthermore, PFOA treatment markedly enhanced the generation of reactive oxygen species and malondialdehyde, with diminished activity of superoxide dismutase. Particularly, PFOA exposure evoked a decline in mitochondrial membrane potential and ATP production. Furthermore, the apoptotic index and caspase-3 activity were significantly elevated after treatment with PFOA. In addition, PFOA incubation caused an increase in LC3B-II/LC3B-I ratio. Meanwhile, PFOA resulted in an excessive accumulation of autophagosomes in the cytoplasm. Taken together, exposure to PFOA can elicit cytotoxicity to spermatogonial GC-1 cells in vitro, which may be link to the mitochondrial oxidative damage and induction of apoptosis and autophagy.

Gestational Perfluorooctanoic Acid Exposure Inhibits Placental Development by Dysregulation of Labyrinth Vessels and uNK Cells and Apoptosis in Mice.

Perfluorooctanoic acid (PFOA) is a widely used perfluorinated compound and known to cause developmental toxicity which includes the increase of resorbed embryo, decrease of fetal survival, and fetal growth retardation. Nevertheless, whether it is associated with alteration of placental development remains unknown. Pregnant mice were gavaged with 0, 2.5, 5, 10 mg PFOA /kg/day from pregnancy day (PD) 1 to PD 13. Results showed that PFOA exposure markedly decreased the placental weight and caused interstitial edema of placenta. Laminin staining indicated that blood sinusoids area was shrunken in placenta of PFOA-exposed mice. Furthermore, PFOA treatment significantly reduced numbers of uNK cells. Western blot analysis revealed that levels of Bax and cleaved-caspase 3 proteins were markedly up-regulated in PFOA-treated groups. In addition, TEM examination showed that PFOA treatment caused rupture of nuclear membrane and nuclear pyknosis and fragmentation. Thus, our results suggested that gestational PFOA exposure significantly inhibited development of early placenta through shrinkage of labyrinth vessels and downregulation of uNK cells and apoptosis induction, which may result in adverse gestational outcomes.

PFOA evokes extracellular Ca2+ influx and compromises progesterone-induced response in human sperm.

Perfluorooctane acid (PFOA), a persistent organic pollutant, is ubiquitously present in the environment and may detrimentally affect male reproductive health. In this study, mature human sperm were in vitro exposed to different concentrations of PFOA (0.25, 2.5 or 25 µg/ml) alone or in combination with progesterone (P4) to evaluate the toxicity and the potential mechanism of action. Exposure to high-dose PFOA (25 µg/ml) alone for 4 h caused a decline in capacity of human spermatozoa to penetrate synthetic mucus, with an increased production of reactive oxygen species (ROS). Furthermore, PFOA treatment (2.5 and 25 µg/ml) evoked a transient rise in intracellular calcium concentration [Ca2+]i by activating the sperm-specific CatSper channel. However, preincubation with PFOA (2.5-25 µg/ml) for 4 h significantly suppressed P4-stimulated extracellular Ca2+ influx in human spermatozoa. Moreover, PFOA pretreatment at all concentrations evaluated markedly compromised P4-induced acrosome reaction and sperm penetration into viscous medium. Taken together, these results suggest that PFOA exposure may impair human sperm function through inducing oxidative stress and disturbing P4-induced Ca2+ signaling.

Tri-ortho-cresyl phosphate (TOCP)-induced reproductive toxicity involved in placental apoptosis, autophagy and oxidative stress in pregnant mice.

Tri-ortho-cresyl phosphate (TOCP) has been widely used as plasticizers, and reported causing reproductive toxicity in mammals. However, little is known about the toxic effect on the placenta. In this study, dams were orally administered different doses of TOCP to explore the effect of TOCP on placental development. Results showed that TOCP exposure significantly reduced numbers of implanted embryo, caused atrophy and collapse of ectoplacental cone, and decreased total areas of placenta and numbers of PCNA-positive cells. Expression levels of placental development genes were prominently downregulated in the TOCP-treated groups. Moreover, TOCP administration induced placental apoptosis and autophagy by upregulating P53, Bax, Beclin-1, ratio of LC3 II/LC3 I and Atg5 and downregulating Bcl-2 protein. In addition, TOCP exposure markedly inhibited activities of catalase and superoxide dismutase and increased the production of H2 O2 and malondialdehyde. Collectively, these findings suggest that apoptosis, autophagy and oxidative stress may be involved in the TOCP-induced reproductive toxicity.

Exposure to acrylamide inhibits uterine decidualization via suppression of cyclin D3/p21 and apoptosis in mice.

Acrylamide (ACR), a neurotoxicity and carcinogenic chemical, has attracted considerable attention since it is present at high concentrations in thermally cooked carbohydrate-rich foods. ACR exposure significantly increased rate of fetal resorption, and decreased fetal body weights in mice. However, no detailed information is available about the effect of ACR on uterine decidualization, which is a vital process in the establishment of successful pregnancy. Thus, our aim of this study was to explore the effect and mechanism of ACR on uterine decidualization in vivo during mice pregnancy. Mice were gavaged with 0, 10, and 50 mg ACR /kg/day from gestational days (GD) 1 until GD 8, whereas pseudopregnant mice from pseudopregnant day (PPD) 4 until PPD 8. Results indicated ACR treatment dramatically reduced numbers of implanted embryos, and decreased the weights of implantation site and oil-induced uterus. Nevertheless, no significant difference was observed in the weights of no oil-induced uterus between control and ACR-treated group. Furthermore, ACR significantly reduced numbers of polyploidy and PCNA-positive decidual cells and expression of cyclin D3 and p21 proteins, and induced apoptosis of decidua, as presented by up-regulation of Bax and cleaved-caspase-3, and decreased Bcl-2 protein during normal pregnant and pseudopregnant process. In summary, ACR exposure significantly inhibited uterine endometrial decidualization via the apoptosis and suppression of cyclin D3/p21 in mice.

Reproductive functions of Kisspeptin/KISS1R Systems in the Periphery.

Kisspeptin and its G protein-coupled receptor KISS1R play key roles in mammalian reproduction due to their involvement in the onset of puberty and control of the hypothalamic-pituitary-gonadal axis. However, recent studies have indicated a potential role of extra-hypothalamic kisspeptin in reproductive function. Here, we summarize recent advances in our understanding of the physiological significance of kisspeptin/KISS1R in the peripheral reproductive system (including the ovary, testis, uterus, and placenta) and the potential role of kisspeptin/KISS1R in reproductive diseases. A comprehensive understanding of the expression, function, and potential molecular mechanisms of kisspeptin/KISS1R in the peripheral reproductive system will contribute to the diagnosis, treatment and prevention of reproductive diseases.

Flutamide ameliorates uterine decidualization and angiogenesis in the mouse hyperandrogenemia model during mid-pregnancy.

BACKGROUND/AIM: Patients with polycystic ovary syndrome (PCOS), characterized by anovulation, hyperandrogenemia and polycystic ovaries, are still vulnerable to undergo recurrent pregnancy loss and premature labor even though the ovulatory process is pharmacologically recovered. However, its potential mechanism remains unknown. Thus, our aim was to investigate the effect and mechanism of hyperandrogenemia and flutamide (a non-steroidal anti-androgen) on the embryo implantation and pregnancy during mid-pregnancy. METHODS: We used a mouse model in which PCOS-like hyperandrogenemia was induced by subcutaneous injection of testosterone propionate. In this model, we observed the effect of hyperandrogenemia and flutamide on the decidualization, angiogenesis and uNK cells by methods of immunohistochemistry, quantitative PCR, western blotting and Dolichos biflorus agglutinin (DBA) lectin staining. RESULTS: Testosterone and flutamide treatment did not significantly influence the numbers of implanted embryo compared with the control group. However, different doses of testosterone significantly increased the ratio of resorbed /implanted embryo, decreased the level of prl8a2 mRNA and cyclin D3 protein, inhibited the uterine angiogenesis and reduced the numbers of uNK cells, but combined treatment with flutamide markedly decreased the resorbed embryos, increased expressions of prl8a2 mRNA and cyclin D3 protein and angiogenesis and numbers of uNK cells. CONCLUSION: Flutamide treatment can efficiently ameliorate the hyperandrogenemia-induced the disorders in aspects of decidualization, angiogenesis and uNK cells, which further improve the poor endometrial receptivity in PCOS patients.