Origin of the multi-phasic quenching dynamics in the BLUF domains across the species.

Blue light using flavin (BLUF) photoreceptors respond to light via one of nature's smallest photo-switching domains. Upon photo-activation, the flavin cofactor in the BLUF domain exhibits multi-phasic dynamics, quenched by a proton-coupled electron transfer reaction involving the conserved Tyr and Gln. The dynamic behavior varies drastically across different species, the origin of which remains controversial. Here, we incorporate site-specific fluorinated Trp into three BLUF proteins, i.e., AppA, OaPAC and SyPixD, and characterize the percentages for the Wout, WinNHin and WinNHout conformations using 19F nuclear magnetic resonance spectroscopy. Using femtosecond spectroscopy, we identify that one key WinNHin conformation can introduce a branching one-step proton transfer in AppA and a two-step proton transfer in OaPAC and SyPixD. Correlating the flavin quenching dynamics with the active-site structural heterogeneity, we conclude that the quenching rate is determined by the percentage of WinNHin, which encodes a Tyr-Gln configuration that is not conducive to proton transfer.

Dissecting the Ultrafast Stepwise Bidirectional Proton Relay in a Blue-Light Photoreceptor.

Proton relays through H-bond networks are essential in realizing the functionality of protein machines such as in photosynthesis and photoreceptors. It has been challenging to dissect the rates and energetics of individual proton-transfer steps during the proton relay. Here, we have designed a proton rocking blue light using a flavin (BLUF) domain with the flavin mononucleotide (FMN)-glutamic acid (E)-tryptophan (W) triad and have resolved the four individual proton-transfer steps kinetically using ultrafast spectroscopy. We have found that after the photo-induced charge separation forming FMN·-/E-COOH/WH·+, the proton first rapidly jumps from the bridging E-COOH to FMN- (τfPT2 = 3.8 ps; KIE = 1.0), followed by a second proton transfer from WH·+ to E-COO- (τfPT1 = 336 ps; KIE = 2.6) which immediately rocks back to W· (τrPT1 = 85 ps; KIE = 6.7), followed by a proton return from FMNH· to E-COO- (τrPT2 = 34 ps; KIE = 3.3) with the final charge recombination between FMN·- and WH·+ to close the reaction cycle. Our results revisited the Grotthuss mechanism on the ultrafast timescale using the BLUF domain as a paradigm protein.

The nature of proton-coupled electron transfer in a blue light using flavin domain.

Proton-coupled electron transfer (PCET) is key to the activation of the blue light using flavin (BLUF) domain photoreceptors. Here, to elucidate the photocycle of the central FMN-Gln-Tyr motif in the BLUF domain of OaPAC, we eliminated the intrinsic interfering W90 in the mutant design. We integrated the stretched exponential function into the target analysis to account for the dynamic heterogeneity arising from the active-site solvation relaxation and the flexible H-bonding network as shown in the molecular dynamics simulation results, facilitating a simplified expression of the kinetics model. We find that, in both the functional wild-type (WT) and the nonfunctional Q48E and Q48A, forward PCET happens in the range of 105 ps to 344 ps, with a kinetic isotope effect (KIE) measured to be ∼1.8 to 2.4, suggesting that the nature of the forward PCET is concerted. Remarkably, only WT proceeds with an ultrafast reverse PCET process (31 ps, KIE = 4.0), characterized by an inverted kinetics of the intermediate FMNH˙. Our results reveal that the reverse PCET is driven by proton transfer via an intervening imidic Gln.

Highly efficient blue quantum-dot light-emitting diodes based on a mixed composite of a carbazole donor and a triazine acceptor as the hole transport layer.

Solution-processed thermally activated delayed fluorescence (TADF) exciplexes were employed as the hole transport layer (HTL) of blue quantum dot (QD) light-emitting diodes (QLEDs) by blending polymer donors of poly(N-vinylcarbazole) (PVK) with small molecular acceptors of 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine (T2T). As a result, the PVK:T2T HTL can harvest holes and electrons leaking from the QD active layer to form exciplex excitons and then this harvested exciton energy can be effectively transferred to the adjacent QD emitters through the Förster resonance energy-transfer process. Furthermore, the TADF exciplexes can enhance the hole mobility of the HTL due to the charge transfer process from the PVK donor to the T2T acceptor under an external electric field. The maximum current efficiency (CE) and external quantum efficiency (EQE) of the fabricated blue ZnCdS/ZnS core/shell QLEDs increase from 4.14 cd A-1 and 7.33% for the PVK HTL to 7.73 cd A-1 and 13.66% for the PVK:(5 wt%)T2T HTL, respectively. Our results demonstrate that the TADF exciplex HTL would be a facile strategy to design high-performance blue QLEDs.

Efficacy of Bariatric Surgery in the Treatment of Women With Obesity and Polycystic Ovary Syndrome.

CONTEXT: The comparative effectiveness of drugs and surgical therapy for women with obesity and polycystic ovary syndrome (PCOS) has not been systematically compared. OBJECTIVE: We aimed to determine the difference in efficacy between drug and bariatric surgery therapy for women with obesity and PCOS. METHODS: This prospective nonrandomized trial enrolled 90 women aged 18 to 40 years with body mass index (BMI) ≥ 27.5 kg/m2 and waist circumference ≥ 85 cm and fulfilling the 2011 Chinese diagnostic criteria for PCOS; 81 subjects completed the study. In the drug group, patients were administered metformin and an oral contraceptive containing ethinyl-estradiol and cyproterone acetate for the first 6 months, and metformin alone for the second 6 months. In the surgical group, patients underwent laparoscopic sleeve gastrectomies. The follow-up period was 12 months. The main outcome was the complete remission of PCOS, requiring 6 consecutive regular menstruation cycles or spontaneous pregnancy. RESULTS: Median BMI at endpoint was 30.1 kg/m2 in the drug group and 23.7 kg/m2 in the surgical group; complete remission rate was 15% and 78%, respectively. Except endpoint BMI, no difference was observed in free androgen index, ovarian morphology, homeostasis model assessment for insulin resistance, and total weight loss between remission and nonremission patients. Logistic regression analyses also revealed that the final BMI was the major factor influencing the remission of PCOS. The cutoff points for the final BMI were 27.5 kg/m2 for the drug group and 26 kg/m2 for the surgical group. Overall, nearly 95% of patients with an endpoint BMI below the cutoff values achieved complete remission. CONCLUSION: Complete remission of PCOS in patients with obesity depends on the final BMI after weight loss. Thus, bariatric surgery should be prioritized for these patients.

The in vitro effects of gibberellin on human sperm motility.

Gibberellin, a plant growth regulator, is widely used to increase the shelf life and quality of fruits and vegetables. In this study, human semen samples were exposed to different concentrations of gibberellin, which reduced spermatozoa motility in vitro. Gibberellin exposure also increased levels of reactive oxygen species and the protein levels of apoptosis markers in human sperm. Gibberellin inhibited the activity of Na+/K+-adenosine triphosphatase (ATPase) and Ca2+-ATPase, which maintain the stability of ions inside and outside the membranes of spermatozoa. Moreover, gibberellin exposure suppressed adenosine triphosphate production and reduced the protein levels of adenosine triphosphate synthases, which may have induced the protein expression of adenosine 5'-monophosphate-activated protein kinase (AMPK) and its phosphorylated form. These results suggest that gibberellin reduces human sperm motility in vitro by increasing reactive oxygen species levels and reducing ATPase activity, which may upregulate AMPK and consequently reduce the fertilization potential of spermatozoa.

[Toxicological characteristics of plant growth regulators and their impact on male reproductive health].

Plant growth regulators (PGRs) have similar physiological and biological effects to those of plant hormones, and therefore are used widely in agroforestry. The residues of PGRs in agricultural products are seriously detrimental to human health because they have been found with hepatotoxicity, nephrotoxicity, genotoxicity, neurotoxicity, even carcinogenicity and teratogenicity. Furthermore, PGRs are suspected to disrupt the function of human and animal reproductive systems. This paper presents an overview on various toxicities of PGRs on human and animal reproductive health and their underlying mechanisms, aiming to arouse people's attention to PGR residues in food and environment and reduce PGR-induced damage to the male reproductive system and to human health as well.

Nicotine exposure impairs germ cell development in human fetal ovaries cultured in vitro.

In the present paper, we found that human fetal ovaries (at ~16 weeks) express the transcripts for several subunits of the nicotinic acetylcholine receptor (nAChR). Exposure to the drug in vitro resulted in the marked increase of apoptosis in the ovaries in a time and dose-dependent manner. Evidence that adverse nicotine effects are potentially due to an increased level of reactive oxygen species (ROS) and consequent DNA damage, both in the ovarian somatic cells and germ cells, are reported. After 4 days of culture, exposure to 1 mM and 10 mM nicotine caused a 50% and 75% decrease, respectively, in the number of oogonia/oocytes present in the fetal ovaries. These results represent the first indication that nicotine may directly cause apoptosis in cells of the fetal human ovary and may lead to a reduction of the ovarian reserve oocytes and consequent precocious menopause in mothers smoking during pregnancy.

Outcomes of neonates born following transfers of frozen-thawed cleavage-stage embryos with blastomere loss: a prospective, multicenter, cohort study.

BACKGROUND: Despite limited information on neonatal safety, the transfer of frozen-thawed cleavage-stage embryos with blastomere loss is common in women undergoing in vitro fertilization. We aimed to evaluate the pregnancy outcomes and safety of frozen-thawed cleavage-stage embryos with blastomere loss. METHODS: This prospective, multicenter, cohort study included all frozen-thawed cleavage-stage embryo transfer (FET) cycles between 2002 and 2012. Pregnancy outcomes and subsequent neonatal outcomes were compared between FET cycles with intact embryos and those with blastomere loss. RESULTS: A total of 12,105 FET cycles were included in the analysis (2259 cycles in the blastomere loss group and 9846 cycles in the intact embryo group). The blastomere loss group showed significantly poorer outcomes with respect to implantation, pregnancy, and live birth rates than the intact embryo group. However, following embryo implantation, the two groups were similar with respect to live birth rates per clinical pregnancy. Among multiple pregnancies (4229 neonates), neonates from the blastomere loss group were at an increased risk of being small for gestational age (aOR = 1.50, 95% CI 1.00-2.25) compared to those from the intact group. A similar trend was observed among singletons (aOR = 1.84, 95% CI 0.99-3.37). No associations were found between blastomere loss and the subsequent occurrence of congenital anomalies or neonatal mortality. However, neonates from the blastomere loss group were at an increased risk of transient tachypnea of the newborn (aOR = 5.21, 95% CI 2.42-11.22). CONCLUSIONS: The transfer of embryos with blastomere loss is associated with reduced conception rates. Once the damaged embryos have implanted, pregnancies appear to have the same probability of progressing to live birth but with an increased risk of small for gestational age neonates and transient tachypnea of the newborn. STUDY REGISTRATION: This study was retrospectively registered at Chinese Clinical Trial Registry. Registration number: ChiCTR-OOC-16007753 . Registration date: 13 January 2016.

Facile synthesis of yolk shell Mn2O3@Mn5O8 as an effective catalyst for peroxymonosulfate activation.

Yolk shell Mn2O3@Mn5O8 was prepared through a facile synthetic procedure and was demonstrated to be a highly efficient and stable catalyst in peroxymonosulfate (PMS) activation for the catalytic degradation of organic contaminants. Mn2O3@Mn5O8 exhibits much improved activity compared with other classic manganese catalysts such as ε-MnO2, Mn2O3 and Mn3O4, and this performance was due to its yolk shell structure, mesoporous shell, well-defined interior voids, particular particle size and mixed valence states. The long-term stability and efficiency of Mn2O3@Mn5O8 was observed in activating PMS to generate sulfate radicals for the removal of various organic pollutants such as phenol, 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DP) and 2,4,6-trichlorophenol (2,4,6-TCP) in aqueous medium. The effects of the initial solution pH, influence of anions, catalyst stability and the temperature effect on 4-CP degradation were also investigated. Furthermore, electron paramagnetic resonance (EPR) spectroscopy and radical quenching tests were employed to investigate sulfate, hydroxyl, superoxide radicals and even 1O2 for organic degradation processes. Finally, a possible activation pathway of Mn2O3@Mn5O8/PMS was proposed that involved the inner-sphere interactions between the HSO5- and the catalyst surface, electron transfer from Mn species to PMS, and the generation of sulfate radicals. These findings provide new insights into PMS activation by using nano-particle catalysts of non-toxic metal oxides.

Starvation during pregnancy impairs fetal oogenesis and folliculogenesis in offspring in the mouse.

Although it is becoming increasingly evident that maternal starvation during pregnancy can have permanent effects on a range of physiological processes in the offspring, scant information is available about the consequence of such condition for oogenesis and hence for lifetime reproductive success of progeny in mammals. In the present study, we address this topic by starving pregnant mice at the time of ovarian differentiation (12.5 days post coitum (dpc)) for three consecutive days and analyzed the consequence first on the survival of the fetal oocytes and their capability to progress throughout the stages of meiotic prophase I (MPI) and then on the postnatal folliculogenesis of the offspring. The results showed that maternal starvation increased apoptosis in the fetal ovaries, resulting in reduction of the oocyte number. Moreover, MPI progression was slowed down in the surviving oocytes and the expression of DNA repair players in the starved ovaries increased. Transcriptome analysis identified 61 differentially expressed genes between control and starved ovaries, the most part of these being involved in metabolic processes. A significant decrease in the percentage of oocytes enclosed in primordial follicles and the expression of oocyte genes critically involved in folliculogenesis such as Nobox, Lhx8 and Sohlh2 in the 3 days post partum (dpp) starved ovaries were found. Finally, at the time of juvenile period (21 dpp), the number of oocytes and antral follicles resulted significantly lower in the ovaries of the offspring from starved mothers in comparison to controls. Our findings support the notion that maternal starvation can affect ovary development in the offspring that could adversely affect their reproductive success in the adult life.

Ochratoxin A exposure decreased sperm motility via the AMPK and PTEN signaling pathways.

Ochratoxin A (OTA), a common mycotoxin found in nature, has been implicated as effecting the function of male reproductive systems. OTA exposure has been shown to decrease sperm production and quality, however, the underlying mechanisms remain unknown. In the current investigation boar sperm exposed to 10 and 100µM OTA in vitro for 24h resulted in significantly decreased motility, in the 100µM OTA treatment group when compared with the control group. The level of reactive oxygen species (ROS) was significantly increased in both of the OTA treatment groups. The increase in ROS activated phosphatase and the tensin homolog deleted on chromosome ten (PTEN) and inhibited the activation of protein kinase B (PKB, AKT), activated adenosine 5'-monophosphate (AMP), and activated protein kinase (AMPK) in the exposed sperm. Furthermore, activation of AMPK was enhanced by a decrease in ATPase. These changes culminated in a decline in boar sperm motility. PTEN/AMPK inhibitors significantly inhibited the expression of the two proteins in the OTA treatment group. In addition, there was increased expression of apoptosis markers in the OTA exposed sperm. In conclusion, these data suggest that OTA exposure affects the sperm motility via the AMPK and PTEN signaling pathways.

Expression pattern of G protein­coupled estrogen receptor 1 (GPER) in human cumulus granulosa cells (CGCs) of patients with PCOS.

Estradiol mediates its actions by binding to classical nuclear receptors, estrogen receptor α (ER-α) and estrogen receptor ß (ER-ß), and the non-classical G protein-coupled estrogen receptor 1(GPER). Several gene knockdown models have shown the importance of the receptors for growth of the oocyte and for ovulation. The aim of our study was to identify the pattern of GPER expression in human cumulus granulosa cells (CGCs) from ovarian follicles at different stages of oocyte maturation, and the differences of GPER expression between polycystic ovary syndrome (PCOS) patients and non-PCOS women. Thirty-eight cases of PCOS patients and a control group of thirty-two infertile women without PCOS were used in this study. GPER's location in CGCs was investigated by immunohistochemistry. Quantitative RT-PCR and western blot were used to identify the quantify GPER expression. Here we demonstrated that GPER was expressed in CGCs of both PCOS patients and non-PCOS women, and the expression of GPER was decreased significantly during oocyte maturation. But the expression levels of GPER in CGCs of PCOS patients and non-PCOS women were not significantly different. The data indicate that GPER may play a role during human oocyte maturation through its action in cumulus granulosa cells. ABBREVIATIONS: AMHRIIs: anti-Mullerian hormone type II receptors; BMI: body mass index; CGCs: cumulus granulosa cells; COH: controlled ovarian hyperstimulation; E2: estradiol; EGFR: epidermal growth factor receptor; ER-α: estrogen receptor; ER-ß: estrogen receptor ß; FF: follicular fluid; FSH: follicle-stimulating hormone; GCs: granulosa cells; GPER: G protein-coupled estrogen receptor 1; GV: germinal vesicle; GVBD: germinal vesicle breakdown; HCG: human chorionic gonadotropin; IRS: immunoreactive score; IVF-ET: in vitro fertilization and embryo transfer; MI: metaphase I; MII: metaphase II; MAPK: mitogen-activated protein kinase; OCCCs: oocyte corona cumulus complexes; PCOS: polycystic ovarian syndrome; q RT-PCR: quantitative real-time PCR: qRT-PCR.

WNT9B in 542 Chinese women with Müllerian duct abnormalities: mutation analysis.

The WNT9B gene is a common organizing signal regulating different segments of the mammalian urogenital system and plays a primary role in the development of the female reproductive tract. The aim of the present work was to examine the presence of WNT mutations in a population of women with Müllerian duct abnormalities (MDA) in order to elucidate whether mutations in WNT9B are causative for MDA in Chinese women. Initially, 191 Chinese MDA patients and 192 healthy individuals (controls) were recruited. All coding regions were amplified by PCR and sequenced to search for variants. To verify the initial results, the numbers of patients and ethnic-matched controls were expanded to 542 and 563, respectively. One known single-nucleotide polymorphism and four novel variants were identified in the first stage: two were synonymous; the other two were rare nonsynonymous novel variants (c.566G>A (p.Arg189Gln) and c.773G>A (p.Arg258His)). None of the four novel variants was found in controls. In the second stage, both novel nonsynonymous variants were detected in MDA cases and controls. The results indicate that mutations in the coding sequence of WNT9B are not responsible for MDA in the Chinese population.

Correlation between steroid hormonal levels and cardiac function in women during controlled ovarian hyperstimulation.

During in vitro fertilization-embryo transfer (IVF-ET) treatment, most women require controlled ovarian hyperstimulation (COH). COH with gonadotropins results in an increase in steroid hormonal levels; however, it is unclear what impact these high concentrations of steroid hormones have on cardiac heart function. The purpose of this study was to examine the effect of high levels of estradiol (E2) and progesterone (P) during COH treatment on cardiac function in women undergoing IVF-ET. A total of 34 women with infertility due to tubal or male factors treated with COH and 28 women with normal menstrual cycles who underwent ovulation monitoring only were enrolled in this study. The serum levels of steroid hormones and the parameters of echocardiography at different time points during the natural menstrual cycles of the control group and the corresponding time points during COH treatment of the study group were compared. The independent sample with the t test, the paired sample with t test, χ(2) test, and Pearson correlation analysis were applied. The steroid hormonal levels were significantly different between natural menstrual cycles and COH treatment cycles. Left ventricular end-diastolic volume (LVEDV) reached the highest level on day 7 after oocyte pickup; in contrast, ejection fraction (LVEF) was the lowest level on the same day. On day 16 after ET, E2 and P levels were maintained in the pregnant women in the study group; however, the levels of those hormones returned to those of a natural menstrual cycle in non-pregnant women. The parameters of LVEF and LVEDV significantly correlated with E2 concentrations. High levels of E2 during COH treatment may temporarily affect cardiac function, suggesting that COH intervention is relatively safe; however, a certain level of risk might exist.

Genome-wide association study identifies eight new risk loci for polycystic ovary syndrome.

Following a previous genome-wide association study (GWAS 1) including 744 cases and 895 controls, we analyzed genome-wide association data from a new cohort of Han Chinese (GWAS 2) with 1,510 polycystic ovary syndrome (PCOS) cases and 2,016 controls. We followed up significantly associated signals identified in the combined results of GWAS 1 and 2 in a total of 8,226 cases and 7,578 controls. In addition to confirming the three loci we previously reported, we identify eight new PCOS association signals at P < 5 × 10(-8): 9q22.32, 11q22.1, 12q13.2, 12q14.3, 16q12.1, 19p13.3, 20q13.2 and a second independent signal at 2p16.3 (the FSHR gene). These PCOS association signals show evidence of enrichment for candidate genes related to insulin signaling, sexual hormone function and type 2 diabetes (T2D). Other candidate genes were related to calcium signaling and endocytosis. Our findings provide new insight and direction for discovering the biological mechanisms of PCOS.

A genome-wide association study reveals that variants within the HLA region are associated with risk for nonobstructive azoospermia.

A genome-wide association study of Han Chinese subjects was conducted to identify genetic susceptibility loci for nonobstructive azoospermia (NOA). In the discovery stage, 802 azoospermia cases and 1,863 controls were screened for genetic variants in the genome. Promising SNPs were subsequently confirmed in two independent sets of subjects: 818 azoospermia cases and 1,755 controls from northern China, and 606 azoospermia cases and 958 controls from central and southern China. We detected variants at human leukocyte antigen (HLA) regions that were independently associated with NOA (HLA-DRA, rs3129878, p(combine) = 3.70 × 10(-16), odds ratio [OR] = 1.37; C6orf10 and BTNL2, rs498422, p(combine) = 2.43 × 10(-12), OR = 1.42). These findings provide additional insight into the pathogenesis of NOA.

[Hysteroscopy for early abortion after IVF-ET: clinical analysis of 84 cases].

OBJECTIVE: To evaluate the results of hysteroscopy in early abortion patients after in vitro fertilization-embryo transfer (IVF-ET). METHODS: We analyzed the hysteroscopy results of 84 early abortion patients after IVF-ET, treated their intrauterine diseases under the hysteroscopy, and observed the pregnancy outcomes of retransfer. RESULTS: Intrauterine diseases were found in 58 (69.05%) of the patients, including intrauterine adhesion in 32 (32/84, 38.10%), endometrial polyps in 12 (12/84, 14.29%), endometritis in 10 (10/84, 11.90%), submucous leiomyoma in 3 (3/84, 3.57%) and septa in 1 (1/84, 1.19%). These 58 patients underwent IVF/ICSI or frozen embryo retransfer within one year after the hysteroscopic treatment, of whom 22 (37.93%) achieved pregnancy and 1 (4.55%) suffered early abortion. CONCLUSION: Hysteroscopy should be taken as the first-choice intervention measure in early abortion after IVF-ET, and appropriate hysteroscopic treatment may improve the outcome of IVF-ET.