PCSK9 involves in the high-fat diet-induced abnormal testicular function of male mice.

In brief: Impaired spermatogenesis resulting from disturbed cholesterol metabolism due to intake of high-fat diet (HFD) has been widely recognized, however, the role of preprotein invertase subtilin 9 (PCSK9), which is a negative regulator of cholesterol metabolism, has never been reported. This study aims to reveal the role of PCSK9 on spermatogenesis induced by HFD in mice. Abstract: Long-term consumption of a high-fat diet (HFD) is an important factor that leads to impaired spermatogenesis exhibiting poor sperm quantity and quality. However, the mechanism of this is yet to be elucidated. Disrupted cholesterol homeostasis is one of many crucial pathological factors which could contribute to impaired spermatogenesis. As a negative regulator of cholesterol metabolism, preprotein invertase subtilin 9 (PCSK9) mediates low density lipoprotein receptor (LDLR) degradation to the lysosome, thereby reducing the expression of LDLR on the cell membrane and increasing serum low-density lipoprotein cholesterol level, resulting in lipid metabolism disorders. Here, we aim to study whether PCSK9 is a pathological factor for impaired spermatogenesis induced by HFD and the underlying mechanism. To meet the purpose of our study, we utilized wild-type C57BL/6 male mice and PCSK9 knockout mice with same background as experimental subjects and alirocumab, a PCSK9 inhibitor, was used for treatment. Results indicated that HFD induced higher PCSK9 expression in serum, liver, and testes, and serum PCSK9 is negatively correlated with spermatogenesis, while both PCSK9 inhibitor treatment and PCSK9 knockout methodologies ameliorated impaired lipid metabolism and spermatogenesis in mice fed a HFD. This could be due to the overexpression of PCSK9 induced by HFD leading to dyslipidemia, resulting in testicular lipotoxicity, thus activating the Bcl-2-Bax-Caspase3 apoptosis signaling pathway in testes, particularly in Leydig cells. Our study demonstrates that PCSK9 is an important pathological factor in the dysfunction of spermatogenesis in mice induced by HFD. This finding could provide innovative ideas for the diagnosis and treatment of male infertility.

Consistency and synchronization of AMPK-glycogen in endometrial epithelial cells are critical to the embryo implantation.

Uterine receptivity to the embryo is crucial for successful implantation. The establishment of uterine receptivity requires a large amount of energy, and abnormal energy regulation causes implantation failure. Glucose metabolism in the endometrium is tissue specific. Glucose is largely stored in the form of glycogen, which is the main energy source for the endometrium. AMP-activated protein kinase (AMPK), an important energy-sensing molecule, is a key player in the regulation of glucose metabolism and its regulation is also tissue specific. However, the mechanism of energy regulation in the endometrium for the establishment of uterine receptivity remains to be elucidated. In this study, we aimed to investigate the energy regulation mechanism of mouse uterine receptivity and its significance in embryo implantation. The results showed that the AMPK, p-AMPK, glycogen synthase 1, and glycogen phosphorylase M levels and the glycogen content in mouse endometrial epithelium varied in a periodic manner under regulation by the ovarian hormone. Specifically, progesterone significantly activated AMPK, promoted glycogenolysis, and upregulated glycogen phosphorylase M expression. AMPK regulated glycogen phosphorylase M expression and promoted glycogenolysis. AMPK was also found to be activated by changes in the energy or glycogen of the endometrial epithelial cells. The inhibition of AMPK activity or glycogenolysis altered the uterine receptivity markers during the window of implantation and ultimately interfered with implantation. In summary, consistency and synchronization of AMPK and glycogen metabolism constitute the core regulatory mechanism in mouse endometrial epithelial cells involved in the establishment of uterine receptivity.

[Progress in the role of endometrial glucose metabolism in embryo implantation].

The synthesis and decomposition of glycogen adjust the blood glucose dynamically to maintain the energy supply required by the cells. As the only hormone that lowers blood sugar in the body, insulin can promote glycogen synthesis by activating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway and increasing glucose transporter translocation, and inhibit gluconeogenesis to lower blood glucose. In the endometrium, glycogen metabolism is active, but gluconeogenesis does not occur. The glycogen metabolism in the endometrium is controlled not only by the classical glucose regulating hormones, but also by the ovarian hormones. The functional activities related to implantation of the endometrium during the implantation window require glucose as energy source. A large amount of glucose is used to synthesize glycogen in the endometrium before implantation, which could meet the increased energy demand for embryo implantation. In diabetes, glycogen metabolism in the endometrium is impaired, which frequently leads to implantation failure and early abortion. This article reviews the glycogen metabolism in the endometrium and discusses its role in embryo implantation, which provide new ideas for embryo implantation research and infertility treatment.

Contribution of high-fat diet-induced PCSK9 upregulation to a mouse model of PCOS is mediated partly by SREBP2.

The incidence of polycystic ovary syndrome (PCOS) due to high-fat diet (HFD) consumption has been increasing significantly. However, the mechanism by which a HFD contributes to the pathogenesis of PCOS has not been elucidated. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key protein that regulates cholesterol metabolism. Our previous study revealed abnormally high PCSK9 levels in serum from patients with PCOS and in serum and hepatic and ovarian tissues from PCOS model mice, suggesting that PCSK9 is involved in the pathogenesis of PCOS. However, the factor that induces high PCSK9 expression in PCOS remains unclear. In this study, Pcsk9 knockout mice were used to further explore the role of PCSK9 in PCOS. We also studied the effects of a HFD on the expression of PCSK9 and sterol regulatory element-binding protein 2 (SREBP2), a regulator of cholesterol homeostasis and a key transcription factor that regulates the expression of PCSK9, and the roles of these proteins in PCOS pathology. Our results indicated HFD may play an important role by inducing abnormally high PCSK9 expression via SREBP2 upregulation. We further investigated the effects of an effective SREBP inhibitor, fatostain, and found that it could reduce HFD-induced PCSK9 expression, ameliorate hyperlipidemia and improve follicular development in PCOS model mice. Our study thus further elucidates the important role of an HFD in the pathogenesis of PCOS and provides a new clue in the prevention and treatment of this disorder.

Progesterone-induced miR-152 interferes with embryonic implantation by downregulating GLUT3 in endometrial epithelium.

To investigate the role of progesterone-induced micro-RNA (miR)-152 in early embryonic development and implantation by regulating GLUT3 in endometrial epithelium, qRT-PCR was used to detect the expression of miR-152, GLUT1, and GLUT3 in the endometrial epithelial cells of female mice. GLUT1 and GLUT3 proteins were detected by immunohistochemical staining in the mouse endometrial epithelium. Bioinformatics prediction associated with a luciferase assay was performed to determine whether GLUT1 and GLUT3 are target genes of miR-152. Specific miR-152 mimics or inhibitors were transfected into the endometrial epithelial cells to, respectively, overexpress or downregulate miR-152. Next, the glucose concentration of uterine fluid was measured by conducting high-performance liquid chromatography in vivo, and the glucose uptake of the endometrial epithelial cells was observed using a fluorometric assay in vitro. Early embryonic development and implantation were also observed after the miR-152 mimics or inhibitors had been transfected. Embryo transfer was observed after the miR-152 mimic transfection. miR-152 was found to directly target and thereby downregulate GLUT3 expression. The expressions of both miR-152 and GLUT3 in the mouse endometrial epithelium had spatiotemporal characteristics on days 1-4 of pregnancy. miR-152 affected the glucose concentration of uterine fluid and the glucose uptake of endometrial epithelial cells. The transfection of specific miR-152 mimics led to impaired embryonic development and implantation. To conclude, in endometrial epithelial cells, progesterone-induced miR-152 downregulates GLUT3 at the posttranscriptional level to maintain a proper glucose concentration in the uterine fluid, which is necessary for early embryonic development and implantation.

[Progress of non-genomic action of estrogen and its impact on female reproduction].

Estrogen is one of the steroid hormones. Besides the genomic action mediated by its intracellular receptor on target cells, there is now increasing body of evidence indicating that estrogen also has non-genomic action. For the non-genomic action, estrogen binds to its receptor on cell membrane, subsequently rapidly activates various intracellular signaling pathways, such as PLC/Ca(2+), ERK/MAPK, cAMP-PKA, PI3K-AKT-NOS, and finally induces biological effects. The non-genomic effects of estrogen on physiologic and pathologic processes have been found in many tissues within the reproductive, nervous and cardiovascular systems and bone etc. In reproductive system, it has been demonstrated that estrogen plays important roles in follicle development, fertilization and embryo implantation, and it is involved in the genesis and development of genital tract tumors and breast cancer. In this review, we focus on the general characteristics of non-genomic action of estrogen, its main nonnuclear signaling pathways and physiological and pathological significance, especially its influences in female reproductive functions.

[Progesterone-induced microRNA-1a inhibits the proliferation of endometrial epithelial cells].

The aim of the present study was to investigate the effects of progesterone (P4)-induced microRNA-1a (miR-1a) on the proliferation of endometrial epithelial cells (EECs) and the underlying mechanism. In vivo, following subcutaneous injection of estradiol (E2) alone (E2 group) or combined injections of E2 and P4 (E2P4 group) in ovariectomized mice, quantitative real-time PCR (qPCR) was used to check the expression of miR-1a-3p in the directly isolated mouse EECs. The agomir or antagomir specific for miR-1a-3p was injected into one side of the uterine horns of ovariectomized mice pretreated with E2 alone or in combination with P4, and the non-specific control agomir or antagomir was injected into their contralateral horns. Flow cytometry was used to analyze the cell cycle of EECs. Immunohistochemistry (IHC) was used to examine the location and expression of cyclin D2, cyclin E1, and cyclin E2 in the uterine tissue sections. In vitro, primary cultured mouse EECs were pretreated with E2 alone (E2 group) or in combination with P4 (E2P4 group). qPCR was used to detect the expression of miR-1a-3p. Exogenous mimic of miR-1a-3p was transfected into E2-pretreated EECs, and EdU incorporation analysis was used to test the proliferation activity of the EECs. The result of in vivo experiment showed that the expression of miR-1a-3p in E2P4 group was significantly higher than that in E2 group (P < 0.05). The miR-1a-3p agomir arrested cell cycle at G1 to S transition in the mice injected subcutaneously with E2 alone (P < 0.05). Conversely, silencing of miR-1a-3p with transfection of miR-1a-3p antagomir promoted the entry of cells into S phase in the mice injected subcutaneously with both E2 and P4 (P < 0.05). The expressions of cyclin E1 and cyclin E2, except for cyclin D2, in uterine sections were also dramatically reduced by miR-1a-3p overexpression in the uterine epithelium (P < 0.05). In vitro, miR-1a-3p was not expressed in the cells of both E2 and E2P4 groups. The mimic of miR-1a-3p decreased EECs proliferation activity (P < 0.05). These results indicate that P4-induced miR-1a can inhibit the expression of cyclin E1 and cyclin E2, consequently suppressing the proliferation of mouse EECs by arresting cells at G1/S phase.

[Effect of Progesterone-induced MicroRNA-152 on the Proliferation of Endometrial Epithelial Cells].

OBJECTIVE: To determine the expression of microRNA-152 induced by progesterone and its effect on the proliferation of endometrial epithelial cells (EECs). METHODS: Cultured EECs, Ishikawa were divided into four groups: control group (C group), 10(-8) mol/L estrogen treated group (E group), 10(-6) mol/L progesterone group (P group) and estrogen plus progesterone treated group (E&P group). The expression of mature microRNA-152 (microRNA-152-3p) of was detected by qRT-PCR. The estrogen treated cells were transfected with mimic-microRNA-152-3p. The estrogen and progesterone treated cells were transfected with inhibitor-microRNA-152-3p. Cell proliferations were detected by CCK-8 assay. The target gene of microRNA-152-3p proteins was predicted using microRNA target databases and validated by Western blot. RESULTS: qRT-PCR showed no difference between C and E groups (P > 0.05) in the expression of microRNA-152-3p. P group had higher expressions of microRNA-152-3p than C group (P < 0.05). E&P group had higher expressions of microRNA-152-3p than C group and P group. MicroRNA target protein prediction suggested that CDC14A is one of direct target proteins of microRNA-152-3p. The results of CCK-8 assay showed that mimic-microRNA-152-3p transfection blocked proliferations of estrogen treated cells and lowered expressions of CDC14A in these cells; while inhibitor-microRNA-152-3p promotes proliferations of estrogen and progesterone treated cells and increased expressions of CDC14A in these cells. CONCLUSION: Progesterone may suppress proliferations of EECs through inducing expressions of microRNA-152-3p. CDC14A is probably one target protein of microRNA-152-3p for its action on EECs.

Relocalisation and activation of integrins induced rapidly by oestrogen via G-protein-coupled receptor 30 in mouse blastocysts.

Integrins are the dominant and final adhesion molecules in the attachment process between the blastocysts and endometrium. It is necessary for oestrogen to rapidly activate mouse blastocysts so that they attach to the endometrial epithelium. Our previous study suggested that oestrogen can rapidly induce an increase in intracellular calcium in mouse blastocysts via G-protein-coupled receptor 30 (GPR30). Thus, we deduced that integrins may be involved in GPR30 mediation of the fast effect of oestrogen on mouse blastocysts in implantation. To prove our hypothesis, we used immunofluorescence staining and in vitro coculture of mouse blastocysts and endometrial epithelial cell line (EECs), Ishikawa cells, in the present study. We found that αv and ß1 integrin clustered in mouse blastocysts, and that ß3 integrin was relocalised to the apical membrane of blastocyst cells when embryos were treated with 1 µM 17ß-estradiol (E2), 1 µM E2 conjugated to bovine serum albumin (E2-BSA) and 1 µM G-1, a specific GPR30 agonist, for 30 min respectively, whereas pretreatment with 1 µM G15, a specific GPR30 antagonist, and 5 µM 1,2-Bis(2-aminophenoxy)ethane-N,N,N'',N''-tetraacetic acid tetrakis (acetoxymethyl ester)(BAPTA/AM), a cellular Ca2+ chelator, blocked the localisation of integrins induced by oestrogen via GPR30 in mouse blastocyst cells. E2, E2-BSA and G-1 increased the fibronectin (FN)-binding activity of integrins in blastocysts, whereas G15 and BAPTA/AM blocked the activation of integrins induced by oestrogen via GPR30 in mouse blastocysts. Inhibition of integrins by Arg-Gly-Asp peptide in blastocysts resulted in their failure to adhere to EECs in vitro, even if oestrogen or G-1 was provided. Together, the results indicate the fast effect of oestrogen via the GPR30 membrane receptor further induces relocalisation and activation of integrins in mouse blastocysts, which play important roles in the adhesion of blastocysts to EECs.

[Estrogen induced rapid increase of intracellular calcium plays important role in the implantation of mouse blastocysts].

OBJECTIVE: To study the roles of the increased intracellular calcium induced rapidly by estrogen in the implantation of mouse blastocysts. METHODS: The mouse blastocysts were collected from the female mice on the pregnant day 4, divided into 3 groups: control, E2-BSA and BAPTA +E2-BSA. Immunofluorescence staining, confocal microscopy, embryo and endometrial epithenial cells co-culture and embryo transfer were used to investigate the effect of increased intracellular calcium induced by E2-BSA on the expression and localization of integrins in blastocysts and their adhesion to endometrial epithenial calls (EECs) and implantation into the endometrium. RESULTS: The increase of intracellular calcium induced rapidly by estrogen could cause the cluster and relocation of integrin av and beta3, and BAPTA might block this effect, the adhesion rate of blastocysts in contol group was 35.5%, BAPTA +E2-BSA group was 26.7% and significantly lower than 65.6% of E2-BSA group (P<0.05), and the implantation rate in BAPTA+E2-BSA group was 11.8%, which was significantly lower than 52.9% of E2-BSA group (P<0.05). CONCLUSION: The rapid increase of intracellular calcium induced by estrogen may cause the relocalization of integrin in blastocysts and their adhesion to ECCs, which is important in the process of implantation.

Expression of aldose reductase in mouse endometrial epithelial cells and its role in sperm capacitation.

The survival, motility and capacitation of sperm in the female reproductive tract are important prerequisites for fertilization. The uterus is the main location for sperm capacitation. One of the most important physiological functions of the endometrial epithelium is to create a suitable uterine environment under the regulation of ovarian hormones, to ensure sperm capacitation. The composition of uterine fluid directly affects sperm capacitation. Fructose is an important component of semen that supports sperm viability and motility. Aldose reductase, a rate-limiting enzyme in the polyol pathway, metabolizes sorbitol and fructose, thereby supplying cells with necessary energy for functional activities. Existing studies have reported the presence aldose reductase in the endometrium, leading us to hypothesize that its expression in endometrial epithelium might promote sperm capacitation by maintaining the uterine environment. Yet, the mechanism of regulation has not been clarified. In this study, we investigated the expression of aldose reductase in mouse endometrial epithelium and its potential role in sperm capacitation. We initially investigated the periodic characteristics of glucose, fructose and sorbitol in uterine fluid. We then studied the temporal and spatial characteristics of aldose reductase in the endometrial epithelium. Next, we examined the effect of aldose reductase on glucose, fructose and sorbitol in uterine fluid. Finally, we explored the effect of aldose reductase on sperm capacitation and fertilization. The results showed that glucose and fructose content in uterine fluid and the expression of aldose reductase fluctuated periodically during physiological periods. Inhibition of aldose reductase in the endometrial epithelium interfered with sperm capacitation and fertilization by reducing the fructose levels in the uterine fluid. To conclude, the aldose reductase-mediated polyol pathway in endometrial epithelial cells is essential to maintain an appropriate fructose environment in the uterine fluid for sperm capacitation and fertilization.

Hyperandrogen-induced polyol pathway flux increase affects ovarian function in polycystic ovary syndrome via excessive oxidative stress.

AIMS: Polycystic ovary syndrome (PCOS) is a common endocrine disorder in the women of childbearing age. It is characterized by hyperandrogenism and abnormal follicular growth and ovulation. The polyol pathway is a glucose metabolism bypass pathway initiated by aldose reductase (ADR). Androgen induces the expression of ADR in the male reproductive tract, which has a general physiological significance for male reproductive function. Here we investigate whether hyperandrogenemia in PCOS leads to increased flux of the polyol pathway in ovarian tissue, which in turn affects follicular maturation and ovulation through oxidative stress. MAIN METHODS: We used clinical epidemiological methods to collect serum and granulosa cells from clinical subjects for a clinical case-control study. At the same time, cell biology and molecular biology techniques were used to conduct animal and cell experiments to further explore the mechanism of hyperandrogen-induced ovarian polyol pathway hyperactivity and damage to ovarian function. KEY FINDINGS: Here, we find that hyperandrogenism of PCOS can induce the expression of ovarian aldose reductase, which leads to the increase of the polyol pathway flux, and affects ovarian function through excessive oxidative stress. SIGNIFICANCE: Our research has enriched the pathological mechanism of PCOS and may provide a new clue for the clinical treatment of PCOS.

[PP2A is involved in the inhibitory effect of progesterone on proliferation of mouse endometrial epithelial cells].

OBJECTIVE: To study the effect of protein phosphatase 2A (PP2A) in the negative regulation of progesterone on the proliferation of mouse endometrial epithelial cells (EECs). METHODS: Mouse EECs were isolated and cultured in vitro, which were divided into four groups when they grown to confluence: control group (P4) was treated with 1 micromol/L progesterone only, group A, B and C were treated respectively with 1 micromol/L progesterone and different concentrations of okadaic acid (5 nmol/L, 10 nmol/L and 20 nmol/L). After 24 h, the numbers of cells in different phases of the cell cycle were counted with flow cytometry. RESULTS: The effect of OA on mouse EECs was concentration-dependent. Compared with control group of P4, the change of cell cycle procession in group A was not obvious. Lower proportion of cells in G1 and G2/M phase and higher proportion of cells in S phase in group B, higher proportion of cells in G1 and S phase and lower proportion of cells in G2/M phase in group C were observed. CONCLUSION: Adequate dose OA inhibiting PP2A could release the inhibitory effect of progesterone on proliferation of mouse EECs obviously, this suggested that PP2A was involved in the inhibitory effect of progesterone on proliferation of EECs by influencing the process of cell cycle.

Expression of SGLT1 in the Mouse Endometrial Epithelium and its Role in Early Embryonic Development and Implantation.

Many functional activities of endometrium epithelium are energy consuming which are very important for maintaining intrauterine environment needed by early embryonic development and establishment of implantation window. Glucose is a main energy supplier and one of the main components of intrauterine fluid. Obviously, glucose transports in endometrium epithelium involve in for these activities but their functions have not been elucidated. In this research, we observed a spatiotemporal pattern of sodium glucose transporter 1 (SGLT1) expression in the mouse endometrium. We also determined that progesterone can promote the expression of SGLT1 in the mouse endometrial epithelium in response to the action of oestrogen. Treatment with the SGLT1 inhibitor phlorizin or small interfering RNA specific for SGLT1 (SGLT1-siRNA) altered glucose uptake in primary cultured endometrial epithelial cells, which exhibited reduced ATP levels and AMPK activation. The injection of phlorizin or SGLT1-siRNA into one uterine horn of each mouse on day 2 of pregnancy led to an increased glucose concentration in the uterine fluid and decreased number of harvested normal blastocysts and decreased expression of integrin αVß3 in endometrial epithelium and increased expression of mucin 1 and lactoferrin in endometrial epithelium and the uterine homogenates exhibited activated AMPK, a decreased ATP level on day 4, and a decreased number of implantation sites on day 5. In embryo transfer experiments, pre-treatment of the uterine horn with phlorizin or SGLT1-siRNA during the implantation window led to a decreased embryo implantation rate on day 5 of pregnancy, even when embryos from normal donor mice were used. In conclusion, SGLT1, which participates in glucose transport in the mouse endometrial epithelium, inhibition and/or reduced expression of SGLT1 affects early embryo development by altering the glucose concentration in the uterine fluid. Inhibition and/or reduced expression of SGLT1 also affects embryo implantation by influencing energy metabolism in epithelial cells, which consequently influences implantation-related functional activities.

The Effects of Altered Endometrial Glucose Homeostasis on Embryo Implantation in Type 2 Diabetic Mice.

Type 2 diabetes mellitus (T2DM) is a disease characterized by hyperglycemia resulting from insulin resistance. In recent years, the incidence of T2DM has been increasing. Women with T2DM often suffer from infertility and early miscarriage; however, the underlying mechanisms remain unclear. Insulin is the most important regulatory hormone of glycogen metabolism. In addition, 5' adenosine monophosphate-activated protein kinase (AMPK) is an important regulator of glycogen metabolism. Patients with T2DM have inhibited AMPK expression in the liver, which leads to impaired glucose metabolism. However, the role of AMPK in endometrial glycogen metabolism has not been reported. In this study, a mouse model of T2DM was established to investigate whether altered endometrial glucose metabolism affects early embryo implantation. Metformin and insulin were used for therapy; the resulting changes to glycogen metabolism and embryo implantation were examined. The results indicate that the concentrations of glycogen decreased significantly in T2DM mice, resulting in insufficient energy supplies for proper endometrial function, and thereby impeding embryonic implantation. Interestingly, endometrial AMPK was not found to be overactivated. Insulin treatment was found to partially resolve the embryo implantation defects in T2DM mice. Metformin improved blood glucose but did not have a significant effect on local endometrial glucose metabolism. This study explored the changes in endometrial glucose metabolism in T2DM mouse, and the effects of these changes on embryo implantation. We found that insulin, but not metformin, significantly resolved embryo implantation problems. These findings will help to increase our understanding of the pathomechanisms of infertility and early miscarriage in women with T2DM.

GLUT4 in Mouse Endometrial Epithelium: Roles in Embryonic Development and Implantation.

GLUT4 is involved in rapid glucose uptake among various kinds of cells to contribute to glucose homeostasis. Prior data have reported that aberrant glucose metabolism by GLUT4 dysfunction in the uterus could be responsible for infertility and increased miscarriage. However, the expression and precise functions of GLUT4 in the endometrium under physiological conditions remain unknown or controversial. In this study, we observed that GLUT4 exhibits a spatiotemporal expression in mouse uterus on pregnant days 1-4; its expression especially increased on pregnant day 4 during the window of implantation. We also determined that estrogen, in conjunction with progesterone, promotes the expression of GLUT4 in the endometrial epithelium in vivo or in vitro. GLUT4 is an important transporter that mediates glucose transport in endometrial epithelial cells (EECs) in vitro or in vivo. In vitro, glucose uptake decreased in mouse EECs when the cells were treated with GLUT4 small interfering RNA (siRNA). In vivo, the injection of GLUT4-siRNA into one side of the mouse uterine horns resulted in an increased glucose concentration in the uterine fluid on pregnant day 4, although it was still lower than in blood, and impaired endometrial receptivity by inhibiting pinopode formation and the expressions of leukemia inhibitory factor (LIF) and integrin ανß3, finally affecting embryonic development and implantation. Overall, the obtained results indicate that GLUT4 in the endometrial epithelium affects embryo development by altering glucose concentration in the uterine fluid. It can also affect implantation by impairing endometrial receptivity due to dysfunction of GLUT4.

[Protective effect of breviscapine on cardiac function in children after cardiopulmonary bypass undergoing open heart surgery].

OBJECTIVE: To assess the condition of myocardial injury after cardiopulmonary bypass (CPB) and the effects of breviscapine (BVC) on cardiac function in children undergoing open heart surgery. METHODS: Thirty-six children (ASA II or III, aged 2-65 months) scheduled to receive ventricular septal defect repairing were randomly assigned to three groups, the control group treated with saline, and the BVC treated groups treated respectively with low dose (0.5 mg/kg) and high dose (1.0 mg/kg) BVC, 12 patients in each group. Saline or BVC (in volume of 15 mL) was administered intravenously after induction of anesthesia with micro-pump within 30 min. Blood levels of troponin I (cTn-I ) and malondialdehyde (MDA) were measured at different time points: pre-operation (T0), during aortic unclamping (T1), and 30 min, 1 h, 6 h, 24 h after aortic unclamping (T2, T3, T4, T5). And the time of operation, CPB, aortic unclamping, and the condition of drainage in 24 h after operation as well as the dosages of narcotics (midazolam, propofol and fentanyl) used were recorded. RESULTS: No significant difference among groups was found in terms of sex ratio, age, body weight, time of aortic unclamping, CPB and operation, as well as the dosages of narcotics used and the volume of post-operation drainage. Compared with baseline (T0), levels of cTn-I at T1, T4 and T5 increased significantly in all three groups (P<0.01), with the peak revealed at T4; cTn-I in the control group were higher than those in the low dose BVC treated group at T1 and T4 (P<0.01), and those in the high dose BVC group at T1, T4, and T5, while it was insignificantly different between the two BVC treated groups. Level of plasmal MDA began to rise in all groups at T1 with the peak revealed at T2, it lowered after then, and reached the baseline at T5; comparison between groups showed that it was lower in the BVC treated groups than in the control group at T1-T4. CONCLUSIONS: Different degree of cardiac injury always happens after open heart surgery and CPB, showing high level of cTn- I within 24 h with the peak revealed at 6 h after aortic unclamping. Intravenous perfusion BVC before CPB at the dose of 0.5 or 1 mg/kg could protect the cardiac function to some extent.

[Application of MHC-Ig/peptide polymer in detecting antigen-specific cytotoxic T lymphocytes in mice with experimental autoimmune uveitis].

OBJECTIVE: To explore the application of MHC-Ig/peptide polymer technique for detecting antigen-specific cytotoxic T lymphocytes (CTLs) in mice with experimental autoimmune uveitis (EAU). METHODS: B10RIII mice were immunized with an interphotoreceptor retinal-binding protein (IRBP) synthetic peptide (IRBP161-180). The in vivo primed T cells were separated and stained with MHC-Ig polymer combined with a panel of truncated peptides derived from IRBP161-180. The level of IRBP-specific CTLs cells was determined by FACS analysis. The CD8+ T cells were isolated from the primed T cells and stimulated with complex polymers containing MHC-Ig and various IRBP-derived peptides. The proliferation of CD8+ T cells was measured by H thymidine incorporation. The production of interferon- (IFN-) in the cell suspensions was measured by ELISA. RESULTS: The IRBP-specific CTLs were detected by MHC-Ig/peptide polymers. The MHC-Ig/IRBP168-177 peptide polymer dtected 12.3% specific CTLs, showing greater ability in stimulating proliferation of CTLs and production of IFN--than the other MHC-Ig/ peptide polymers (P < 0.01). The truncated 10-mer peptide, IRBP168-177, was the major antigenic epitope for the IRBP-specific CTLs. The MHC-Ig/IRBP168-177 peptide polymer detected the highest level(4.9% +/- 1.1%) of specific CTLs from peripheral blood mononuclear cells (PBMCs) at the acute stage of EAU. CONCLUSION: The MHC-Ig polymer technique is an effective instrument for detecting antigen-specific CTLs, with good sensitivity and specificity in EAU studies.

Impact of Disturbed Glucose Homeostasis Regulated by AMPK in Endometrium on Embryo Implantation in Diabetes Mice.

The incidence of diabetes in women of childbearing age has been increasing recently and implantation failure and early abortion are important reasons for infertility in diabetic women. Glycogen synthesis and decomposition are the cores of glucose homeostasis in endometrium and AMPK is activated when cellular energy consumption increases. Embryo implantation is a complex process required huge energy. Yet the changes of glucose metabolism in endometrium and its impact on embryo implantation in diabetic women are still unclear. In this research, we established diabetic pregnancy mice model by intraperitoneal injecting streptozotocin on pregnant day 1. We first tested the changes of endometrial glucose homeostasis and embryo implantation. Next, we demonstrated abnormal activation of AMPK in the endometrium of diabetic mice and its affecting endometrial glucose homeostasis. Finally, we compared the endometrial glucose homeostasis and embryo implantation outcome in diabetic pregnant mice treated with insulin or insulin combined with metformin. The results indicated that there was disturbed glucose homeostasis associated with excessive activation of AMPK in endometrium of diabetic pregnant mice. AMPK inhibitor improved the over-activation of AMPK pathway in the endometrium, meanwhile, partially corrected the abnormal glycogen metabolism and improved the implantation. Insulin improved the disorder of endometrial glucose homeostasis and implantation of diabetic mice. Our research explores the causes of high abortion and infertility rate in diabetic women which is to provide a therapeutic reference for patients with diabetes complicated with infertility and early abortion.

[Mechanisms of nongenomic effect of 17beta-estradiol on human spermatozoa].

OBJECTIVE: To study the mechanisms of nongenomic effect of 17beta-estradiol on human spermatozoa. METHODS: The intracellular calcium ([Ca2+]i) in the spermatozoa was measured by flow cytometry after the spermatozoa was treated with the inhibitors of trans-membrane signaling transduction pathways and impermeable 17beta-estradiol (E2-BSA). Western blot was used to detect the activation of the signal proteins after the spermatozoa was treated with 1 x 10(-6) mol/L E2-BSA and tamoxifen, an estrogen receptor inhibitor. RESULTS: Adenylyl cyclase (AC) inhibitor SQ22536, phospholipase C (PLC) inhibitor U73122 and protein tyrosine kinase (TPK) inhibitor Genistein all deterred the increase of [Ca2+]i caused by E2-BSA. E2-BSA also increased the PLC protein and PKC protein significantly. Tamoxifen, an antagonist of estrogen receptor, did not inhibit the activation of PLC caused by E2-BSA. CONCLUSION: The E2-BSA has an effect on human spermatozoa in a nongenomic pathway, possibly through the transmembrane signal transduction in relation to AC, PLC and TPK.