Exploratory study of sea buckthorn enhancing QiangGuYin efficacy by inhibiting CKIP-1 and Notum activating the Wnt/ß-catenin signaling pathway and analysis of active ingredients by molecular docking.

Background: Sea buckthorn (SBT) is a traditional Chinese medicine (TCM), rich in calcium, phosphorus, and vitamins, which can potentially prevent and treat osteoporosis. However, no research has been conducted to confirm these hypotheses. QiangGuYin (QGY) is a TCM compound used to treat osteoporosis. There is a need to investigate whether SBT enhances QGY efficacy. Objectives: The aim of this study was to explore whether SBT enhances QGY efficacy by inhibiting CKIP-1 and Notum expression through the Wnt/ß-catenin pathway. The study also aimed to explore the active components of SBT. Methods: Experimental animals were divided into control, model, QGY, SBT, SBT + Eucommia ulmoides (EU), and SBT + QGY groups. After treatment, bone morphometric parameters, such as estrogen, PINP, and S-CTX levels, and Notum, CKIP-1, and ß-catenin expression were examined. Screening of SBT active components was conducted by molecular docking to obtain small molecules that bind Notum and CKIP-1. Results: The results showed that all the drug groups could elevate the estrogen, PINP, and S-CTX levels, improve femoral bone morphometric parameters, inhibit Notum and CKIP-1 expression, and promote ß-catenin expression. The effect of SBT + EU and SBT + QGY was superior to the others. Molecular docking identified that SBT contains seven small molecules (folic acid, rhein, quercetin, kaempferol, mandenol, isorhamnetin, and ent-epicatechin) with potential effects on CKIP-1 and Notum. Conclusion: SBT improves bone morphometric performance in PMOP rats by inhibiting CKIP-1 and Notum expression, increasing estrogen levels, and activating the Wnt/ß-catenin signaling pathway. Furthermore, SBT enhances the properties of QGY. Folic acid, rhein, quercetin, kaempferol, mandenol, isorhamnetin, and ent-epicatechin are the most likely active ingredients of SBT. These results provide insight into the pharmacological mechanisms of SBT in treating osteoporosis.

Role of interaction between reactive oxygen species and ferroptosis pathway in methylglyoxal-induced injury in mouse embryonic osteoblasts / 南方医科大学学报

OBJECTIVE@#To explore the interaction between reactive oxygen species (ROS) and ferroptosis in methylglyoxalinduced injury of mouse embryonic osteoblasts (MC3T3-E1 cells).@*METHODS@#MC3T3-E1 cells were treated with methylglyoxal to establish a cell model of diabetic osteoporosis. CCK-8 assay was used to detect the viability of MC3T3-E1 cells. Rhodamine 123 staining followed by photofluorography was used to examine mitochondrial membrane potential (MMP). The intracellular ROS level was detected by 2', 7'-dichlorodihydrofluorescein diacetate staining with photofluorograph. Alkaline phosphatase (ALP) activity in the cells was detected using an ALP kit, the number of mineralized nodules was determined with alizarin red S staining, and the level of iron ions was detected using a detection kit. The expression level of glutathione peroxidase 4 (GPX4, a marker protein that inhibits ferroptosis) in the osteoblasts was determined using Western blotting.@*RESULTS@#Treatment of MC3T3-E1 cells with 0.6 mmol/L methylglyoxal for 24 h significantly inhibited the expression level of GPX4 (P < 0.001), increased intracellular iron ion concentration, decreased the cell viability, increased the loss of MMP and intracellular ROS level, decreased both ALP activity and the number of mineralized nodules in the cells (P < 0.001). Co-treatment of MC3T3-E1 cells with 2 mmol/L N-acetylcysteine (NAC, a ROS scavenger) and methylglyoxal significantly increased the expression level of GPX4 (P < 0.01); co-treatment with 4 mmo/L FER-1 (a ferroptosis inhibitor) and methylglyoxal obviously decreased the intracellular ROS level (P < 0.001). Co-treatment of the cells either with NAC and methylglyoxal or with FER-1 and methylglyoxal attenuated methylglyoxal-induced injuries in the osteoblasts (P < 0.001).@*CONCLUSION@#The interaction between ROS and ferroptosis pathway plays an important role in methylglyoxal-induced injury of mouse embryonic osteoblasts.

Nomogram to predict pregnancy outcomes of emergency oocyte freeze-thaw cycles.

BACKGROUND: Existing clinical prediction models for in vitro fertilization are based on the fresh oocyte cycle, and there is no prediction model to evaluate the probability of successful thawing of cryopreserved mature oocytes. This research aims to identify and study the characteristics of pre-oocyte-retrieval patients that can affect the pregnancy outcomes of emergency oocyte freeze-thaw cycles. METHODS: Data were collected from the Reproductive Center, Peking University Third Hospital of China. Multivariable logistic regression model was used to derive the nomogram. Nomogram model performance was assessed by examining the discrimination and calibration in the development and validation cohorts. Discriminatory ability was assessed using the area under the receiver operating characteristic curve (AUC), and calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test and calibration plots. RESULTS: The predictors in the model of "no transferable embryo cycles" are female age (odds ratio [OR] = 1.099, 95% confidence interval [CI] = 1.003-1.205, P = 0.0440), duration of infertility (OR = 1.140, 95% CI = 1.018-1.276, P = 0.0240), basal follicle-stimulating hormone (FSH) level (OR = 1.205, 95% CI = 1.051-1.382, P = 0.0084), basal estradiol (E2) level (OR = 1.006, 95% CI = 1.001-1.010, P = 0.0120), and sperm from microdissection testicular sperm extraction (MESA) (OR = 7.741, 95% CI = 2.905-20.632, P < 0.0010). Upon assessing predictive ability, the AUC for the "no transferable embryo cycles" model was 0.799 (95% CI: 0.722-0.875, P < 0.0010). The Hosmer-Lemeshow test (P = 0.7210) and calibration curve showed good calibration for the prediction of no transferable embryo cycles. The predictors in the cumulative live birth were the number of follicles on the day of human chorionic gonadotropin (hCG) administration (OR = 1.088, 95% CI = 1.030-1.149, P = 0.0020) and endometriosis (OR = 0.172, 95% CI = 0.035-0.853, P = 0.0310). The AUC for the "cumulative live birth" model was 0.724 (95% CI: 0.647-0.801, P < 0.0010). The Hosmer-Lemeshow test (P = 0.5620) and calibration curve showed good calibration for the prediction of cumulative live birth. CONCLUSIONS: The predictors in the final multivariate logistic regression models found to be significantly associated with poor pregnancy outcomes were increasing female age, duration of infertility, high basal FSH and E2 level, endometriosis, sperm from MESA, and low number of follicles with a diameter >10 mm on the day of hCG administration.

RBM14 Modulates Tubulin Acetylation and Regulates Spindle Morphology During Meiotic Maturation in Mouse Oocytes.

RBM14 is an RNA-binding protein that regulates spindle integrity in mitosis; however, its functions during meiosis are still unclear. In this study, we discovered that RBM14 expression was down-regulated in oocytes from old mice. The RBM14 distribution at different stages of meiosis was explored, while it presents overlapped localization patterns with α-tubulin in MI- and MII-stage oocytes. Treatment of MI-stage oocytes with spindle-perturbing agents revealed that RBM14 was co-localized with microtubules. RBM14 knockdown with RBM14-specific morpholino showed that RBM14-depleted oocytes underwent symmetric division compared to the controls. RBM14 knockdown also resulted in spindle defects and chromosome abnormalities during oocyte maturation, presumably due to α-tubulin hyperacetylation. Co-immunoprecipitation analysis demonstrated that RBM14 is interacted with endogenous α-tubulin in mammalian cells. These findings indicate that RBM14 is an essential modulator of oocyte meiotic maturation by regulating α-tubulin acetylation to affect spindle morphology and chromosome alignment. Consequently, RBM14 represents a potential biomarker of oocyte quality and a novel therapeutic target in women with oocyte maturation failure.

Perioperative Complications and Safety Evaluation of Robot-Assisted Radical Hysterectomy of Cervical Cancer After Neoadjuvant Chemotherapy.

PURPOSE: To evaluate the perioperative complications of patients with cervical cancer who are treated with robot-assisted radical hysterectomy (RRH) and to further evaluate the safety of patients undergoing NACT. METHODS: A total of 805 consecutive cervical cancer patients undergoing RRH were involved in this report. Their clinical characteristics were retrieved from hospital medical records. Perioperative complications were subdivided into intraoperative and postoperative complications, which were graded according to the Clavien-Dindo classification (CDC), and the complications of grade III and above were defined as severe complications. Furthermore, the two-level logistic regression model was used to estimate the risk factors of perioperative and severe complications and to further confirm the relationship between NACT and perioperative and severe complications. RESULTS: The perioperative complication rate and severe complications were 45.09% and 7.83%, respectively. Poorly differentiated tumor and NACT were identified as independent risk factors for perioperative complications by multifactor analysis. Furthermore, we concentrated on the relations between NACT and complications. The risk of perioperative complications of the group with NACT (OR = 11.08, 95% CI: 5.70-21.54) was significantly higher than the group without NACT, especially in postoperative complications (OR=17.65, 95% CI: 8.63-36.08), even after adjusting confounding factors. However, there was no statistically significant difference in terms of severe complications (OR=1.68, 95% CI: 0.64-4.41) and intraoperative complications (OR=0.51, 95% CI: 0.18-1.41). Moreover, as the times of NACT increase, the impact on perioperative complications is more pronounced. A similar trend was observed in postoperative complications, while this statistical difference was still not observed in intraoperative and severe complications. CONCLUSION: This result demonstrates the feasibility and safety of RRH of cervical carcinoma after NACT in generally, since it only causes mild complications, not severe complications.

Cyclopamine functions as a suppressor of benign prostatic hyperplasia by inhibiting epithelial and stromal cell proliferation via suppression of the Hedgehog signaling pathway.

Stromal­epithelial interaction serves a pivotal role in normal prostate growth, as well as the onset of benign prostatic hyperplasia (BPH). The present study aimed to explore the role of cyclopamine in the proliferation and apoptosis of epithelial and stromal cells in rats with BPH by blocking the Hedgehog signaling pathway. Cyclopamine (an inhibitor of the Hedgehog signaling pathway) was administered in a rat model of BPH, and the expression of Ki67 (proliferation factor) was determined by immunohistochemistry. In addition, epithelial and stromal cells were separated and cultured in order to investigate the role of cyclopamine in the progression of BPH. The expression of Hedgehog signaling pathway­ and apoptosis­related genes, including basic fibroblastic growth factor (b­FGF) and transforming growth factor ß (TGF­ß), was evaluated using reverse transcription­quantitative polymerase chain reaction and western blot analysis. Cell proliferation, cell cycle and apoptosis were analyzed using an MTT assay and flow cytometry. We identified upregulated Ki67 expression and activated Hedgehog signaling pathway in rats with BPH. Cyclopamine inhibited the activation of the Hedgehog signaling pathway. In response to cyclopamine treatment, epithelial and stromal cell proliferation was inhibited; this was concomitant with decreased Ki67, TGF­ß, and b­FGF expression. On the other hand, epithelial cell apoptosis was enhanced, which was associated with increased Bax and reduced Bcl­2 expression. Based on these findings, we proposed that cyclopamine may serve as a potential therapeutic agent in the treatment of BPH. Cyclopamine could inhibit epithelial and stromal cell proliferation, and induce epithelial cell apoptosis by suppressing the Hedgehog signaling pathway.

Enhancing the scope of in vitro maturation for fertility preservation: transvaginal retrieval of immature oocytes during endoscopic gynaecological procedures.

STUDY QUESTION: Could in vitro maturation (IVM) following transvaginal oocyte retrieval during gynaecological surgery (IVM-surgery) be an effective and safe strategy for fertility preservation? SUMMARY ANSWER: IVM-surgery on unstimulated ovaries is a novel option that can be considered for fertility preservation for women requiring gynaecological surgery, but more research is needed to identify appropriate patients who may benefit and to determine the cost-effectiveness of such an approach. WHAT IS KNOWN ALREADY: IVM followed by oocyte/embryo cryopreservation has been useful as a safe reproductive strategy for some infertile women. STUDY DESIGN, SIZE, DURATION: This prospective cohort study comprised 158 consecutive women with polycystic ovary syndrome (PCOS) who underwent laparoscopy or hysteroscopy for other reasons and had concomitant transvaginal oocyte retrieval followed by IVM between 2014 and 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 158 women with anovulatory PCOS who underwent IVM-surgery in our infertility centre were recruited for this study. Matured IVM oocytes obtained from these women were either freshly fertilized and subsequently frozen at the blastocyst stage (fresh oocyte group, n = 46) or the oocytes were frozen (frozen oocyte group, n = 112) for fertility preservation followed by later thawing for insemination and cleavage embryo transfer (ET) (n = 33). The following outcomes were then evaluated: embryological data, clinical pregnancy rate, live birth rate (LBR), neonatal outcomes, post-operative complications and post-operative ovarian function. MAIN RESULTS AND THE ROLE OF CHANCE: Among all the women who underwent IVM-surgery, the clinical pregnancy rate and LBR per initiated IVM cycle were 9.5% (15/158) and 6.9% (11/158), respectively. Women (40.6%, 20/33) who underwent the procedure with frozen-thawed oocytes (oocyte survival rate, 83.0%) obtained a high quality of cleaved embryos. In the fresh oocyte group, the clinical pregnancy rate and LBR per ET cycle were 69.2 and 53.8%, respectively. In the frozen oocyte group, the clinical pregnancy rate and LBR per ET cycle were 28.6 and 19.1%, respectively. No adverse neonatal outcomes were recorded. IVM-surgery was not associated with post-operative complications, a longer hospital stay, or impaired ovarian function. LIMITATIONS, REASONS FOR CAUTION: Because of the small sample size and the low utilization rate and cost-effectiveness per retrieval, the present findings should be interpreted with caution, and further studies are needed for the long-term follow-up of live births. WIDER IMPLICATIONS OF THE FINDINGS: This strategy can also help patients with normal ovulation to obtain available oocytes and embryos for cryopreservation and subsequent use. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by the Joint Research Fund for Overseas Natural Science of China (No. 31429004), the National Key Research and Development Program of China (No. 2017YFC1002000, 2017YFC1001504, 2016YFC1000302), the Ministry of Science and Technology of China Grants (No. 2014CB943203), the Chinese Society of Reproductive Medicine Fund (No. 16020400656) and the National Natural Science Foundation of China (No. 81300456). All the authors have nothing to disclose in terms of conflicts of interest. TRIAL REGISTRATION NUMBER: chictr-ONC-17011861.

Ubiquitylomes Analysis of the Whole blood in Postmenopausal Osteoporosis Patients and healthy Postmenopausal Women.

OBJECTIVES: To determine the mechanisms of ubiquitination in postmenopausal osteoporosis and investigate the ubiquitinated spectrum of novel targets between healthy postmenopausal women and postmenopausal osteoporosis patients, we performed ubiquitylome analysis of the whole blood of postmenopausal women and postmenopausal osteoporosis patients. METHODS: To obtain a more comprehensive understanding of the postmenopausal osteoporosis mechanism, we performed a quantitative assessment of the ubiquitylome in whole blood from seven healthy postmenopausal women and seven postmenopausal osteoporosis patients using high-performance liquid chromatography fractionation, affinity enrichment, and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). To examine the ubiquitylome data, we performed enrichment analysis using an ubiquitylated amino acid motif, Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. RESULTS: Altogether, 133 ubiquitinated sites and 102 proteins were quantified. A difference of more than 1.2 times is considered significant upregulation and less than 0.83 significant downregulation; 32 ubiquitinated sites on 25 proteins were upregulated and 101 ubiquitinated sites on 77 proteins were downregulated. These quantified proteins, both with differently ubiquitinated sites, participated in various cellular processes, such as cellular processes, biological regulation processes, response to stimulus processes, single-organism and metabolic processes. Ubiquitin conjugating enzyme activity and ubiquitin-like protein conjugating enzyme activity were the most highly enriched in molecular function of upregulated sites with corresponding proteins, but they were not enriched in downregulated in sites with corresponding proteins. The KEGG pathways analysis of quantified proteins with differentiated ubiquitinated sites found 13 kinds of molecular interactions and functional pathways, such as glyoxylate and decarboxylate metabolism, dopaminergic synapse, ubiquitin-mediated proteolysis, salivary secretion, coagulation and complement cascades, Parkinson's disease, and hippo signaling pathway. In addition, hsa04120 ubiquitin-mediated proteolysis was the most highly enriched in proteins with upregulated sites, hsa04610 complement and coagulation cascades was the most highly enriched in proteins with downregulated ubiquitinated sites, and hsa04114 Oocyte meiosis was the most highly enriched among all differential proteins. CONCLUSION: Our study expands the understanding of the spectrum of novel targets that are differentially ubiquitinated in whole blood from healthy postmenopausal women and postmenopausal osteoporosis patients. The findings will contribute toward our understanding of the underlying proteostasis pathways in postmenopausal osteoporosis and the potential identification of diagnostic biomarkers in whole blood.

Vitamin D Ameliorates Impaired Wound Healing in Streptozotocin-Induced Diabetic Mice by Suppressing Endoplasmic Reticulum Stress.

BACKGROUND: This study is designed to investigate whether vitamin D promotes diabetic wound healing and explore the potential mechanism which may be involved in the healing process. MATERIAL AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with 200 µg/ml of advanced glycation end product-modified human serum albumin (AGE-HSA) and 250 mg/dl of glucose with vitamin D. Cell viability was analyzed using the CCK-8 assay, and the apoptosis rate was measured using flow cytometry. Endogenous markers of ER stress were quantified using Western blot and a real-time polymerase chain reaction. Diabetic mice were treated with vitamin D (100 ng/kg per day) for 14 days. The ulcer area and ulcerative histology were detected dynamically. RESULTS: Vitamin D administration not only decreased the apoptosis rate but also increased cell viability. Furthermore, the expression of endogenous markers of ER stress was downregulated as a result of vitamin D treatment. Vitamin D supplementation significantly accelerated wound healing of diabetic mice and improved the healing quality. Further studies showed that reduced ER stress was associated with the positive outcome. CONCLUSION: These results suggest that vitamin D may ameliorate impaired wound healing in diabetic mice by suppressing ER stress.

Specific PKC ßII inhibitor: one stone two birds in the treatment of diabetic foot ulcers.

To explore whether or not inhibition of protein kinase C ßII (PKC ßII) stimulates angiogenesis as well as prevents excessive NETosis in diabetics thus accelerating wound healing. Streptozotocin (STZ, 60 mg/kg/day for 5 days, i.p.) was injected to induce type I diabetes in male ICR mice. Mice were treated with ruboxistaurin (30 mg/kg/day, orally) for 14 consecutive days. Wound closure was evaluated by wound area and number of CD31-stained capillaries. Peripheral blood flow cytometry was done to evaluate number of circulating endothelial progenitor cells (EPCs). NETosis assay and wound tissue immunofluorescence imaging were done to evaluate the percentage of neutrophils undergoing NETosis. Furthermore, the expression of PKC ßII, protein kinase B (Akt), endothelial nitric oxide synthase (eNOS), vascular endothelial growth factor (VEGF), and histone citrullation (H3Cit) were determined in the wound by Western blot analysis. Ruboxistaurin accelerated wound closure and stimulated angiogenesis in diabetic mice. The number of circulating EPCs was increased significantly in ruboxistaurin-treated diabetic mice. Moreover, ruboxistaurin treatment significantly decreases the percentages of H3Cit+ cells in both peripheral blood and wound areas. This prevented excess activated neutrophils forming an extracellular trap (NETs) formation. The expressions of phospho-Akt (p-Akt), phospho-eNOS (p-eNOS), and VEGF increased significantly in diabetic mice on ruboxistaurin treatment. The expressions of PKC ßII and H3Cit+, on the other hand, decreased with ruboxistaurin treatment. The results of the present study suggest that ruboxistaurin by inhibiting PKC ßII activation, reverses EPCs dysfunction as well as prevents exaggerated NETs formation in a diabetic mouse model; thereby accelerating the wound healing process.

Predictors of delayed wound healing after successful isolated below-the-knee endovascular intervention in patients with ischemic foot ulcers.

OBJECTIVE: The purpose of this study was to explore the predictors of delayed wound healing and their use in risk stratification for endovascular treatment (EVT) of patients with critical limb ischemia (CLI) due to isolated below-the-knee lesions. METHODS: Wound healing rates were analyzed retrospectively in patients who underwent successful below-the-knee percutaneous transluminal balloon angioplasty for CLI with tissue loss between May 2008 and June 2013. We also analyzed the independent predictors of delayed wound healing and their use in risk stratification. RESULTS: The cumulative wound healing rates were 13.9%, 43.8%, 57.7%, and 65.7% at 3, 6, 9, and 12 months, respectively. Multivariate Cox proportional hazards analysis revealed the following as independent predictors of wound nonhealing after initial successful EVT: patients with end-stage renal disease receiving dialysis (hazard ratio [HR], 2.6; 95% confidence interval [CI], 1.0-6.3; P  = .04); albumin level <3.0 g/dL (HR, 2.0; 95% CI, 1.1-3.8; P  = .02); C-reactive protein level >5.0 mg/dL (HR, 3.9; 95% CI, 1.6-9.6; P = .003); major tissue loss (HR, 2.1; 95% CI, 1.3-3.4; P = .003); wound infection (HR, 1.9; 95% CI, 1.2-2.9; P = .005); gangrene (HR, 1.8; 95% CI, 1.2-2.8; P = .008); wound depth (University of Texas grade 3; HR, 3.4; 95% CI, 1.4-8.6; P = .009); duration of ulcer (≥2 months; HR, 2.9; 95% CI, 1.0-8.4; P = .048); insulin use (HR, 1.7; 95% CI, 1.0-2.8; P = .04); and lack of below-the-ankle runoff (HR, 1.9; 95% CI, 1.0-3.4; P = .04). CONCLUSIONS: The general status of the patient and the target limb's condition are important predictors of wound nonhealing. Regarding the limb's condition, information on wound depth and duration in addition to wound extent and infection would further enable the selection of suitable CLI patients for EVT. Such information would also enable optimal wound management, leading to successful wound healing and improved limb salvage and survival rates.

An Overview on Current Issues and Challenges of Endothelial Progenitor Cell-Based Neovascularization in Patients with Diabetic Foot Ulcer.

Diabetic foot ulcer's impaired wound healing, which leads to the development of chronic non-healing wounds and ultimately amputation, is a major problem worldwide. Although recently endothelial progenitor cell-derived cell therapy has been used as a therapeutic intervention to treat diabetic wounds, thereby promoting neovascularization, the results, however, are not satisfactory. In this article, we have discussed the several steps that are involved in the neovascularization process, which might be impaired during diabetes. In addition, we have also discussed the reported possible interventions to correct these impairments. Thus, we have summarized neovascularization as a process with a coordinated sequence of multiple steps and thus, there is the need of a combined therapeutic approach to achieve better treatment outcomes.

The cohesion stabilizer sororin favors DNA repair and chromosome segregation during mouse oocyte meiosis.

Maintenance and timely termination of cohesion on chromosomes ensures accurate chromosome segregation to guard against aneuploidy in mammalian oocytes and subsequent chromosomally abnormal pregnancies. Sororin, a cohesion stabilizer whose relevance in antagonizing the anti-cohesive property of Wings-apart like protein (Wapl), has been characterized in mitosis; however, the role of Sororin remains unclear during mammalian oocyte meiosis. Here, we show that Sororin is required for DNA damage repair and cohesion maintenance on chromosomes, and consequently, for mouse oocyte meiotic program. Sororin is constantly expressed throughout meiosis and accumulates on chromatins at germinal vesicle (GV) stage/G2 phase. It localizes onto centromeres from germinal vesicle breakdown (GVBD) to metaphase II stage. Inactivation of Sororin compromises the GVBD and first polar body extrusion (PBE). Furthermore, Sororin inactivation induces DNA damage indicated by positive γH2AX foci in GV oocytes and precocious chromatin segregation in MII oocytes. Finally, our data indicate that PlK1 and MPF dissociate Sororin from chromosome arms without affecting its centromeric localization. Our results define Sororin as a determinant during mouse oocyte meiotic maturation by favoring DNA damage repair and chromosome separation, and thereby, maintaining the genome stability and generating haploid gametes.

TRAIP is involved in chromosome alignment and SAC regulation in mouse oocyte meiosis.

Recent whole-exome sequencing (WES) studies demonstrated that TRAIP is associated with primordial dwarfism. Although TRAIP was partially studied in mitosis, its function in oocyte meiosis remained unknown. In this study, we investigated the roles of TRAIP during mouse oocyte meiosis. TRAIP was stably expressed during oocytes meiosis and co-localized with CREST at the centromere region. Knockdown of TRAIP led to DNA damage, as revealed by the appearance of γH2AX. Although oocytes meiotic maturation was not affected, the proportions of misaligned chromosomes and aneuploidy were elevated after TRAIP knockdown, suggesting TRAIP is required for stable kinetochore-microtubule (K-MT) attachment. TRAIP knockdown decreased the accumulation of Mad2 on centromeres, potentially explaining why oocyte maturation was not affected following formation of DNA lesions. Securin, a protein which was prevent from precocious degradation by Mad2, was down-regulated after TRAIP knockdown. Inhibition of TRAIP by microinjection of antibody into pro-metaphase I (pro-MI) stage oocytes resulted in precocious first polar body (PB1) extrusion, and live-cell imaging clearly revealed misaligned chromosomes after TRAIP knockdown. Taken together, these data indicate that TRAIP plays important roles in oocyte meiosis regulation.

Oocyte-expressed yes-associated protein is a key activator of the early zygotic genome in mouse.

In early mammalian embryos, the genome is transcriptionally quiescent until the zygotic genome activation (ZGA) which occurs 2-3 days after fertilization. Despite a long-standing effort, maternal transcription factors regulating this crucial developmental event remain largely elusive. Here, using maternal and paternal mouse models of Yap1 deletion, we show that maternally accumulated yes-associated protein (YAP) in oocyte is essential for ZGA. Maternal Yap1-knockout embryos exhibit a prolonged two-cell stage and develop into the four-cell stage at a much slower pace than the wild-type controls. Transcriptome analyses identify YAP target genes in early blastomeres; two of which, Rpl13 and Rrm2, are required to mediate maternal YAP's effect in conferring developmental competence on preimplantation embryos. Furthermore, the physiological YAP activator, lysophosphatidic acid, can substantially improve early development of wild-type, but not maternal Yap1-knockout embryos in both oviduct and culture. These observations provide insights into the mechanisms of ZGA, and suggest potentials of YAP activators in improving the developmental competence of cultured embryos in assisted human reproduction and animal biotechnology.

SUMO-1 plays crucial roles for spindle organization, chromosome congression, and chromosome segregation during mouse oocyte meiotic maturation.

Small ubiquitin-related modifier-1 (SUMO-1)-dependent modifications of many target proteins are involved in a range of intracellular processes. Previous studies reported the localization of SUMO-1 during oocyte meiosis, and that overexpression of Sentrin/SUMO-specific protease 2 (SENP2), a de-SUMOylation protease, altered SUMO-modified proteins, and caused defects in metaphase-II spindle organization. In this study, we detailed the consequences of SUMO-1-mediated SUMOylation by either inhibition of SUMO-1 or UBC9 with a specific antibody or their depletion by specific siRNA microinjection. Inhibition or depletion of SUMO-1 or UBC9 in germinal vesicle (GV)-stage oocytes decreased the rates of germinal vesicle breakdown and first polar body (PB1) extrusion; caused defective spindle organization and misaligned chromosomes; and led to aneuploidy in matured oocytes. Stage-specific antibody injections suggested that SUMO-1 functions before anaphase I during PB1 extrusion. Further experiments indicated that the localization of γ-tubulin was disordered after SUMO-1 inhibition, and that SUMO-1 depletion disrupted kinetochore-microtubule attachment at metaphase I. Moreover, SUMO-1 inhibition resulted in less-condensed chromosomes, altered localization of REC8 and securin, and reduced BUBR1 accumulation at the centromere. On the other hand, overexpression of SUMO-1 in GV-stage oocytes had no significant effect on oocyte maturation. In conclusion, our results implied that SUMO-1 plays crucial roles during oocyte meiotic maturation, specifically involving spindle assembly and chromosome behavior, by regulating kinetochore-microtubule attachment and the localization of γ-tubulin, BUBR1, REC8, and securin.

Knockdown of CEBPß by RNAi in porcine granulosa cells resulted in S phase cell cycle arrest and decreased progesterone and estradiol synthesis.

Cultured ovarian granulosa cells (GCs) are essential models to study molecular mechanisms of gene regulation during folliculogenesis. CCAAT enhancer binding proteins ß (CEBPß) has been identified in the ovary and is critical for follicular growth, ovulation and luteinization in mice. In the present study, hormonal treatment indicated that luteinizing hormone (LH) and exogenous human chorionic gonadotropins (hCG) significantly increased the expression of CEBPß in porcine GCs. By RNAi-Ready pSIREN-RetroQ-ZsGreen Vector mediated recombinant pshRNA vectors, CEBPß gene was successfully knocked down in porcine GCs, confirmed by mRNA and protein level analyzed by real time PCR and western blot, respectively. We further found that knockdown of CEBPß significantly increased the expression of p-ERK1/2. Furthermore, CEBPß knockdown arrested the GCs at S phase of cell cycle, but had no effects on cell apoptosis. More importantly, it markedly down regulated the concentration of estradiol (E2) and progesterone (P4) in the culture medium. To uncover the regulatory mechanism of CEBPß knockdown on cell cycle and steroids synthesis, we found that the mRNA expression of bcl-2 (anti-apoptosis), StAR and Runx2 (steroid hormone synthesis) was up-regulated, while genes related to apoptosis (Caspase-3 and p53), hormonal synthesis (CYP11A1) and cell cycle (cyclinA1, cyclinB1, cyclinD1) were down-regulated, suggesting that knockdown of CEBPß may inhibit apoptosis, regulate cell cycle and hormone secretions at the transcriptional level in porcine GCs. Furthermore, knockdown of CEBPß significantly increased the expression of PTGS2 and decreased the expression of IGFBP4, Has2 and PTGFR which are important for folliculogenesis in porcine GCs. In conclusion, this study reveals that CEBPß is a key regulator of porcine GCs through modulation of cell cycle, apoptosis, steroid synthesis, and other regulators of folliculogenesis.

SUMOylation of mouse p53b by SUMO-1 promotes its pro-apoptotic function in ovarian granulosa cells.

Follicular atresia is a process of spontaneous degradation of follicles, hindering growth and development in the mammalian ovary. Previous studies showed that follicular atresia was caused by apoptosis of granulosa cells, for which a number of apoptosis-related genes have already been identified. The roles of p53 in apoptosis of mouse granulosa cells and its post-translational modification are still unclear. The main objective of this study was to explore the roles of p53 in mouse granulosa cells. We found that mouse p53b, but not p53a, could be SUMOylated by SUMO-1 at lysine 375, which was essential for the protein stability of p53b in a dose-dependent manner. Immunofluorescent staining showed that wild p53b was located in the nucleus of granulosa cells, while its mutation of SUMOylated site (K375R) was localized in both nucleus and cytoplasm, implying that SUMOylation was necessary for the nuclear localization of p53b in granulosa cells. Overexpression of wild-type p53b, but not the mutation of SUMOylation site (K375R), significantly induced the expression of apoptosis-related gene, Bax, and increased the level of apoptosis in granulosa cells. This suggested that SUMO-1 modification of p53b was essential for inducing apoptosis in granulosa cells. Our results provide strong evidences that modification of p53b by SUMO-1 at lysine 375 was necessary for its activity to induce apoptosis in mouse granulosa cells, and it was involved in the regulation of p53b protein stability and nuclear localization. This implies that modification of p53b by SUMO-1 might regulate follicular atresia by inducing the apoptosis of ovarian granulosa cells in mice.

Bora regulates meiotic spindle assembly and cell cycle during mouse oocyte meiosis.

Bora is the binding partner of Aurora A, which is required for its activation and phosphorylation of Polo like kinase 1 (Plk1), and is involved in the spindle assembly and progress of the cell cycle during mitosis. In this study, we examined the expression, localization, and function of Bora during mouse oocyte meiosis. The expression level of Bora was increased during oocyte meiotic maturation, with an elevated level at metaphase. Immunofluorescence analysis showed that Bora was concentrated as a dot shortly after germinal vesicle breakdown (GVBD), associating first with the surrounding chromosomes and then with the spindle throughout oocyte meiotic maturation. Further experiments confirmed that Bora co-localized with α-tubulin at prometaphase/metaphase, but dissociated from α-tubulin at anaphase/telophase. In metaphase-II-arrested oocytes, Bora was evenly distributed in the cytoplasm after treatment with a microtubule-depolymerizing agent, or recruited to the spindle after treatment with a microtubule-polymerizing agent, indicating that Bora was physically connected to the meiotic spindle and α-tubulin at metaphase. Furthermore, inhibition or depletion of Bora by either anti-Bora antibody or Bora siRNA microinjection significantly reduced the rates of GVBD and inhibited first polar body extrusion; caused morphologically defective spindles and misaligned chromosomes; arrested maturing oocytes at prometaphase/metaphase-I stage, or left oocytes and their first polar bodies with severely misaligned chromosomes and defective spindles; and/or caused the disappearance of Aurora A and Plk1 at the spindle. These results indicated that Bora acts as a critical regulator of Aurora A and Plk1, and is involved in microtubule organization during oocyte meiosis.