Testosterone-Induced H3K27 Deacetylation Participates in Granulosa Cell Proliferation Suppression and Pathogenesis of Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is the leading cause of infertility in reproductive-age women. Hyperandrogenism, polycystic ovaries, and chronic anovulation are its typical clinical features. However, the correlation between hyperandrogenism and ovarian follicle growth aberrations remains undisclosed. To advance our understanding of the molecular alterations in ovarian granulosa cells (GCs) with excessive androgen, epigenetic changes and affected gene expression in human granulosa-lutein cells and immortalized human GCs were evaluated. A PCOS mouse model induced by dihydrotestosterone was also established. This study found excessive testosterone significantly decreased the acetylation of lysine 27 on histone H3 (H3K27ac). H3K27ac chromatin immunoprecipitation- sequencing data showed down-regulated expression of cell cycle-related genes (CCND1/CCND3/PCNA), which was confirmed by real-time quantitative PCR and Western blot analysis. Testosterone application impeding cell proliferation was also proved by Ki-67 immunofluorescence and flow-cytometric analysis. Moreover, testosterone influenced CK2α nuclear translocation, which increased the phosphorylation level of histone deacetylase 2 (HDAC2). Inhibition of CK2α nuclear translocation or silenced HDAC2 expression efficiently retarded H3K27 acetylation. Meanwhile, PCOS mouse model experiments also demonstrated decreased H3K27ac and enhanced HDAC2 phosphorylation in GCs. Cell proliferation-related genes were also down-regulated in PCOS mouse GCs. In conclusion, hyperandrogenism in human and mouse GCs caused H3K27Ac aberrations, which are associated with CK2α nuclear translocation and HDAC2 phosphorylation, participating in abnormal follicle development in patients with PCOS.

CRL4DCAF13 E3 ubiquitin ligase targets MeCP2 for degradation to prevent DNA hypermethylation and ensure normal transcription in growing oocytes.

The DNA methylation is gradually acquired during oogenesis, a process sustained by successful follicle development. However, the functional roles of methyl-CpG-binding protein 2 (MeCP2), an epigenetic regulator displaying specifical binding with methylated DNA, remains unknown in oogenesis. In this study, we found MeCP2 protein was highly expressed in primordial and primary follicle, but was almost undetectable in secondary follicles. However, in aged ovary, MeCP2 protein is significantly increased in both oocyte and granulosa cells. Overexpression of MeCP2 in growing oocyte caused transcription dysregulation, DNA hypermethylation, and genome instability, ultimately leading to follicle growth arrest and apoptosis. MeCP2 is targeted by DCAF13, a substrate recognition adaptor of the Cullin 4-RING (CRL4) E3 ligase, and polyubiquitinated for degradation in both cells and oocytes. Dcaf13-null oocyte exhibited an accumulation of MeCP2 protein, and the partial rescue of follicle growth arrest induced by Dcaf13 deletion was observed following MeCP2 knockdown. The RNA-seq results revealed that large amounts of genes were regulated by the DCAF13-MeCP2 axis in growing oocytes. Our study demonstrated that CRL4DCAF13 E3 ubiquitin ligase targets MeCP2 for degradation to ensure normal DNA methylome and transcription in growing oocytes. Moreover, in aged ovarian follicles, deceased DCAF13 and DDB1 protein were observed, indicating a potential novel mechanism that regulates ovary aging.

Mutations in OOEP and NLRP5 identified in infertile patients with early embryonic arrest.

The subcortical maternal complex (SCMC), composed of several maternal-effect genes, is vital for the development of oocytes and early embryos. Variants of SCMC-encoding genes (NLRP2, NLRP5, TLE6, PADI6, and KHDC3L, but not OOEP and ZBED3) are associated with human oocyte maturation dysfunction, fertilization failure, and early embryonic arrest. In this study, we enrolled 118 Chinese patients who experienced recurrent preimplantation embryonic arrest during assisted reproductive technology treatments and performed whole-exome sequencing. We discovered compound heterozygous missense variants (c.110G>C and c.109C>G) in the OOEP gene in one patient who experienced recurrent preimplantation embryonic arrest. Arrested embryos from this affected patient were analyzed by single-cell RNA sequencing, which showed a downregulated transcriptome. In addition, six novel NLRP5 variants (c.971T>A, c.3341T>C, c.1575_1576delAG, c.1830_1831delGT, c.1202C>T, and c.2378T>G) were identified in four patients with arrested and severely fragmented embryos. These suspicious mutations were examined by in vitro studies in HEK293T cells. Western blot analysis and immunofluorescence experiments showed that OOEP and partial NLRP5 mutations caused decreased protein levels. Our findings first demonstrated that biallelic variants in OOEP gene could also cause human early embryonic arrest, similar to other SCMC components. We expanded the genetic mutation spectrum of SCMC genes related to early embryogenesis in humans, especially early embryonic arrest.

DCAF13 promotes breast cancer cell proliferation by ubiquitin inhibiting PERP expression.

Evolutionarily conserved DDB1-and CUL4-associated factor 13 (DCAF13) is a recently discovered substrate receptor for the cullin RING-finger ubiquitin ligase 4 (CRL4) E3 ubiquitin ligase that regulates cell cycle progression. DCAF13 is overexpressed in many cancers, although its role in breast cancer is currently elusive. In this study we demonstrate that DCAF13 is overexpressed in human breast cancer and that its overexpression closely correlates with poor prognosis, suggesting that DCAF13 may serve as a diagnostic marker and therapeutic target. We knocked down DCAF13 in breast cancer cell lines using CRISPR/Cas9 and found that DCAF13 deletion markedly reduced breast cancer cell proliferation, clone formation, and migration both in vitro and in vivo. In addition, DCAF13 deletion promoted breast cancer cell apoptosis and senescence, and induced cell cycle arrest in the G1/S phase. Genome-wide RNAseq analysis and western blotting revealed that loss of DCAF13 resulted in both mRNA and protein accumulation of p53 apoptosis effector related to PMP22 (PERP). Knockdown of PERP partially reversed the hampered cell proliferation induced by DCAF13 knockdown. Co-immunoprecipitation assays revealed that DCAF13 and DNA damage-binding protein 1 (DDB1) directly interact with PERP. Overexpression of DDB1 significantly increased PERP polyubiquitination, suggesting that CRL4DCAF13 E3 ligase targets PERP for ubiquitination and proteasomal degradation. In conclusion, DCAF13 and the downstream effector PERP occupy key roles in breast cancer proliferation and potentially serve as prognostics and therapeutic targets.

DCAF13 promotes pluripotency by negatively regulating SUV39H1 stability during early embryonic development.

Mammalian oocytes and zygotes have the unique ability to reprogram a somatic cell nucleus into a totipotent state. SUV39H1/2-mediated histone H3 lysine-9 trimethylation (H3K9me3) is a major barrier to efficient reprogramming. How SUV39H1/2 activities are regulated in early embryos and during generation of induced pluripotent stem cells (iPSCs) remains unclear. Since expression of the CRL4 E3 ubiquitin ligase in oocytes is crucial for female fertility, we analyzed putative CRL4 adaptors (DCAFs) and identified DCAF13 as a novel CRL4 adaptor that is essential for preimplantation embryonic development. Dcaf13 is expressed from eight-cell to morula stages in both murine and human embryos, and Dcaf13 knockout in mice causes preimplantation-stage mortality. Dcaf13 knockout embryos are arrested at the eight- to sixteen-cell stage before compaction, and this arrest is accompanied by high levels of H3K9me3. Mechanistically, CRL4-DCAF13 targets SUV39H1 for polyubiquitination and proteasomal degradation and therefore facilitates H3K9me3 removal and zygotic gene expression. Taken together, CRL4-DCAF13-mediated SUV39H1 degradation is an essential step for progressive genome reprogramming during preimplantation embryonic development.

CNOT6L couples the selective degradation of maternal transcripts to meiotic cell cycle progression in mouse oocyte.

Meiotic resumption-coupled degradation of maternal transcripts occurs during oocyte maturation in the absence of mRNA transcription. The CCR4-NOT complex has been identified as the main eukaryotic mRNA deadenylase. In vivo functional and mechanistic information regarding its multiple subunits remains insufficient. Cnot6l, one of four genes encoding CCR4-NOT catalytic subunits, is preferentially expressed in mouse oocytes. Genetic deletion of Cnot6l impaired deadenylation and degradation of a subset of maternal mRNAs during oocyte maturation. Overtranslation of these undegraded mRNAs caused microtubule-chromosome organization defects, which led to activation of spindle assembly checkpoint and meiotic cell cycle arrest at prometaphase. Consequently, Cnot6l-/- female mice were severely subfertile. The function of CNOT6L in maturing oocytes is mediated by RNA-binding protein ZFP36L2, not maternal-to-zygotic transition licensing factor BTG4, which interacts with catalytic subunits CNOT7 and CNOT8 of CCR4-NOT Thus, recruitment of different adaptors by different catalytic subunits ensures stage-specific degradation of maternal mRNAs by CCR4-NOT This study provides the first direct genetic evidence that CCR4-NOT-dependent and particularly CNOT6L-dependent decay of selective maternal mRNAs is a prerequisite for meiotic maturation of oocytes.

Decreased histidine-rich glycoprotein and increased complement C4-B protein levels in follicular fluid predict the IVF outcomes of recurrent spontaneous abortion.

BACKGROUND: Recurrent spontaneous abortion (RSA) is a common and complicated pregnancy-related disease that lacks a suitable biomarker to predict its recrudescence. METHODS: Tandem mass tag (TMT) analysis was conducted to obtain quantitative proteomic profiles in follicular fluid from patients with a history of RSA and from control group. ELISA validation of candidate differentially expressed proteins was conducted in a larger group of patients. RESULTS: A total of 836 proteins were identified by TMT analysis; 51 were upregulated and 47 were downregulated in follicular fluid from cases of RSA versus control group. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed several important pathways were enriched, involving a dysregulated immunoglobulin Fc receptor signaling pathway and overactivated complement cascade pathways. ELISA validated the differential expression of two proteins, histidine-rich globulin (HRG) and complement C4-B (C4B), which were downregulated and upregulated, respectively, in follicular fluid of patients with RSA. We performed receiver operating characteristic curve analysis of the ELISA results with the outcomes of current IVF cycles as classification variables. The area under the curve results for HRG alone, C4B alone and HRG-C4B combined were 0.785, 0.710 and 0.895, respectively. CONCLUSIONS: TMT analysis identified 98 differentially expressed proteins in follicular fluid from patients with RSA, indicating follicle factors that act as early warning factors for the occurrence of RSA. Among them, HRG and C4B provide candidate markers to predict the clinical outcomes of IVF/ICSI cycles, and the potential for modeling an early detection system for RSA.

Biallelic variants in MOS cause large polar body in oocyte and human female infertility.

STUDY QUESTION: What is the genetic basis of female infertility involving abnormal oocyte morphology with the production of a large first polar body (PB1)? SUMMARY ANSWER: The homozygous missense variant (c.791C>G) and compound missense variants (c.596A>T and c.875C>T) in MOS proto-oncogene, serine/threonine kinase (MOS) (Online Mendelian Inheritance in Man (OMIM) reference: 190060; NM_005372.1) are responsible for abnormal oocyte morphology with the production of a large PB1 to cause infertility in women. WHAT IS KNOWN ALREADY: MOS, an oocyte-specific gene, encodes a serine/threonine-protein kinase that directly phosphorylates mitogen-activated protein kinase (MAPK) kinase (MEK) to activate MAPK (also called extracellular-signal-regulated kinase (ERK)) signal cascade in the oocyte. Female mice lacking Mos remained viable, but infertile because of oocyte symmetric division, spontaneous parthenogenetic activation and early embryonic arrest. Recently, two independent studies demonstrated that female infertility with early embryonic arrest and fragmentation can be caused by biallelic mutations in MOS. However, so far, MOS variants have not been associated with the phenotype of large PB1 extrusion in human oocytes to contribute to female infertility. STUDY DESIGN, SIZE, DURATION: Two independent infertile families characterized by the presence of large PB1 in oocytes were recruited between December 2020 and February 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: Genomic DNA was extracted from the peripheral blood samples of the subjects for whole-exome sequencing. Pedigree analysis was validated by Sanger sequencing. Then, the pathogenic effects of the MOS variants on MOS protein properties and ERK1/2 activation were determined in HEK293 cells and mouse oocytes. MAIN RESULTS AND THE ROLE OF CHANCE: We identified three rare missense variants in MOS, including a homozygous missense variant (c.791C>G) from Patient 1 in Family 1 and two compound missense variants (c.596A>T and c.875C>T) from twin sisters in Family 2. The MOS variants followed a recessive inheritance pattern in infertile patients. All three patients displayed a high percentage of large PB1 extrusion in the oocytes. The three MOS variants could not activate MEK1/2 and ERK1/2 in oocytes and HEK293 cells. In addition, when compared with wild-type MOS, the MOS variants decreased the MOS protein level and attenuated the binding capacity with MEK1. Microinjection of wild-type human MOS complementary RNAs (cRNAs) reversed the symmetric division of oocytes after siMos treatment. In contrast, the three MOS variants demonstrated no rescuing ability. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Owing to the scarcity of human oocyte samples and the associated ethical restrictions, we could not perform the rescue attempt for the study patients. WIDER IMPLICATIONS OF THE FINDINGS: Our findings expand the genetic and phenotypic spectrum of MOS variants in causing female infertility. Our study findings facilitate the early genetic diagnosis of abnormal oocyte morphology characterized as large PB1 that eventually causes infertility in women. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the National Natural Science Foundation of China (82071640 and 82001633), Natural Science Foundation of Zhejiang Province (LD22C060001), the Key Projects Jointly Constructed by the Ministry and the Province of Zhejiang Medical and Health Science and Technology Project (WKJ-ZJ-2005), China Postdoctoral Science Foundation (2020M682575 and 2021T140198), the Changsha Municipal Natural Science Foundation (kq2007022) and Hunan Provincial Grant for Innovative Province Construction (2019SK4012). None of the authors declare any competing interests. TRIAL REGISTRATION NUMBER: N/A.

Clinical characteristics of anti-isoleucyl-tRNA synthetase antibody associated syndrome and comparison with different patient cohorts.

OBJECTIVES: This study aimed to analyse the clinical features of anti-isoleucyl-tRNA synthetase (OJ) antibodies in Chinese patients and to compare with previously published cohorts. We reviewed the clinical data of anti-OJ antibody positive patients, including their long-term follow-up. RESULTS: Anti-OJ antibodies were present in 10 of 1269 (0.8%) patients with idiopathic inflammatory myopathies (IIMs), and 10/320 (3.1%) patients with anti-synthetase syndrome (ASS). Of the anti-OJ antibody-positive patients, 90% had interstitial lung disease (ILD), of whom three (30%) developed rapidly progressive ILD (RP-ILD). Half (50%) of the patients were febrile and developed myocardial involvement; 40% of patients experienced myositis, mechanic's hands and arthritis. Compared to the anti-Jo-1 group, the levels of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in the anti-OJ antibody-positive group were higher (p<0.05). From a review of the literature regarding the clinical features of anti-OJ, fever was more common in the eastern cohort (41.7% vs. 8.3%, p=0.002), whereas patients in western countries were more likely to develop arthritis (20.9% vs. 58.1%, p=0.001). With complete follow-up of the present cohort, 80% improved with treatment, including one patient who underwent lung transplant. CONCLUSIONS: The anti-OJ antibody occurred infrequently in Chinese patients, ILD was the major clinical feature, but myocardial injury was also a prominent associated complication. Anti-OJ positive patients were responsive to treatment.

The CRL4-DCAF13 ubiquitin E3 ligase supports oocyte meiotic resumption by targeting PTEN degradation.

Cullin ring-finger ubiquitin ligase 4 (CRL4) has multiple functions in the maintenance of oocyte survival and meiotic cell cycle progression. DCAF13, a novel CRL4 adaptor, is essential for oocyte development. But the mechanisms by which CRL4-DCAF13 supports meiotic maturation remained unclear. In this study, we demonstrated that DCAF13 stimulates the meiotic resumption-coupled activation of protein synthesis in oocytes, partially by maintaining the activity of PI3K signaling pathway. CRL4-DCAF13 targets the polyubiquitination and degradation of PTEN, a lipid phosphatase that inhibits PI3K pathway as well as oocyte growth and maturation. Dcaf13 knockout in oocytes caused decreased CDK1 activity and impaired meiotic cell cycle progression and chromosome condensation defects. As a result, chromosomes fail to be aligned at the spindle equatorial plate, the spindle assembly checkpoint is activated, and most Dcaf13 null oocytes are arrested at the prometaphase I. The DCAF13-dependent PTEN degradation mechanism fits in as a missing link between CRL4 ubiquitin E3 ligase and PI3K pathway, both of which are crucial for translational activation during oocyte GV-MII transition.

Novel WEE2 compound heterozygous mutations identified in patients with fertilization failure or poor fertilization.

PURPOSE: To study associations between novel WEE2 mutations and patients with fertilization failure or poor fertilization. METHODS: Thirty-one Chinese patients who underwent treatment with assisted reproductive technology and suffered from repeated (at least two times) total fertilization failure (TFF) or a low fertilization rate were enrolled. Genomic DNA was extracted from patients for whole-exome sequencing. Suspicious mutations were validated by Sanger sequencing. WEE2 protein levels in oocytes from affected patients were examined by immunofluorescence. Disruptive effects of mutations on WEE2 protein stability, subcellular localization, and kinase function were analyzed through western blotting, immunofluorescence, and flow cytometry in HeLa cells. RESULTS: Three of thirty-one (9.6%) enrolled patients had six compound heterozygous mutations of the WEE2 gene, and three of them were reported here for the first time (c.115_116insT, c.756_758delTGA, and c.C1459T). Oocytes from affected patients showed decreased WEE2 immunofluorescence signals. In vitro experiments showed that the mutant WEE2 gene caused reduced WEE2 protein levels or cellular compartment translocation in HeLa cells, leading to decreased levels of the phosphorylated Cdc2 protein. Compared with the wild-type WEE2 protein, the mutant WEE2 proteins were also found to have different effects on the cell cycle. CONCLUSION: Three novel compound heterozygous WEE2 variants were found in patients with pronucleus formation failure. This study provides new evidence that WEE2 mutations result in loss of function, which could result in fertilization failure.

A MAPK cascade couples maternal mRNA translation and degradation to meiotic cell cycle progression in mouse oocytes.

Mammalian oocyte maturation depends on the translational activation of stored maternal mRNAs upon meiotic resumption. Cytoplasmic polyadenylation element binding protein 1 (CPEB1) is a key oocyte factor that regulates maternal mRNA translation. However, the signal that triggers CPEB1 activation at the onset of mammalian oocyte maturation is not known. We provide evidence that a mitogen-activated protein kinase (MAPK) cascade couples maternal mRNA translation to meiotic cell cycle progression in mouse oocytes by triggering CPEB1 phosphorylation and degradation. Mutations of the phosphorylation sites or ubiquitin E3 ligase binding sites in CPEB1 have a dominant-negative effect in oocytes, and mimic the phenotype of ERK1/2 knockout, by impairing spindle assembly and mRNA translation. Overexpression of the CPEB1 downstream translation activator DAZL in ERK1/2-deficient oocytes partially rescued the meiotic defects, indicating that ERK1/2 is essential for spindle assembly, metaphase II arrest and maternal-zygotic transition (MZT) primarily by triggering the translation of key maternal mRNAs. Taken together, ERK1/2-mediated CPEB1 phosphorylation/degradation is a major mechanism of maternal mRNA translational activation, and is crucial for mouse oocyte maturation and MZT.

Copper-Catalyzed Radical Cascade Cyclization To Access 3-Sulfonated Indenones with the AIE Phenomenon.

An efficient copper-catalyzed radical cascade cyclization strategy was developed, by which a wide variety of 3-sulfonyl substituted indenones were prepared in one pot via reaction of 2-alkynylbenzonitriles with sulfonyl hydrazides in the presence of TBHP and CuI under mild reaction conditions. Much more importantly, the 3-sulfonyl indenones, synthesized through our newly developed copper-catalyzed radical cascade cyclization strategy, were found to own typical aggregation-induced emission (AIE) properties, showing orange to red emission with large Stokes shift (more than 135 nm). In addition, such newly found AIEgens could be successfully used in live cell imaging, exhibiting excellent biocompatibility and application potential.

The polycystic ovary syndrome-associated gene Yap1 is regulated by gonadotropins and sex steroid hormones in hyperandrogenism-induced oligo-ovulation in mouse.

STUDY QUESTION: What is the physiological function of Yes-associated protein-1 (Yap1), a susceptibility gene for polycystic ovary syndrome (PCOS), in ovarian granulosa cells (GCs)? SUMMARY ANSWER: Physiologically, steroid sex hormones stimulate follicle growth by activating YAP1; however, the preovulatory inhibition of YAP1 activity in GCs is a prerequisite of LH actions. WHAT IS KNOWN ALREADY: PCOS is a common gynecologic and endocrine disease with multiple short and long-term consequences. Many PCOS patients suffer anovulation caused by hyperandrogenism, but its etiology remains unclear. STUDY DESIGN, SIZE, DURATION: To study the effect of acute hyperandrogenism on ovulation, we injected pregnant mare serum gonadotrophin (PMSG)-primed (44 h) pubertal mice with dihydrotestosterone (DHT), the major biologically active form of androgen, in a superovulation assay. We investigated if YAP1 is regulated by testosterone and if it is potentially involved in follicle development and ovulation. Cultured primary GCs were subjected to Yap1 depletion by RNA interference and Yap1 overexpression by adenoviral infections. PARTICIPANTS/MATERIALS, SETTING, METHODS: Female mice at postnatal day (PD)-21~23 were analyzed to avoid the complexity of ovarian functions associated with estrous cycles and endogenous surges of gonadotropins. Immature mice were injected intraperitoneally with five IU PMSG to stimulate preovulatory follicle development followed 44 h later with five IU hCG to stimulate ovulation. For DHT treatments, female mice at PD23 were injected intraperitoneally with five IU PMSG followed 44 h later with five IU hCG alone (as control) or five IU hCG plus 100 µg DHT, which was dissolved in 0.1 ml DMSO. Methods of gene expression detection used include immunohistochemistry, immunofluorescence, Western blotting and quantitative PCR. More than three biological and technical replicates were included in each experiments. MAIN RESULTS AND THE ROLE OF CHANCE: we provide novel evidence in a mouse model that YAP1 is required for proliferation of ovarian GCs, but is down-regulated by LH through the extracellular-regulated kinase-1/2 (ERK1/2) cascade. Acute hyperandrogenism blocks LH actions and causes oligo-ovulation by activating YAP1. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Results shown were obtained only in mouse, and need to be further confirmed in human samples. WIDER IMPLICATIONS OF THE FINDINGS: These findings not only elucidated the role of YAP1 in maintaining normal ovarian functions, but also link the YAP1 deregulation to the pathogenesis of PCOS. STUDY FUNDING AND COMPETING INTEREST(S): This study is funded by the National Key Research and Development Program of China (2016YFC1000600 and 2017YFSF1001500) and National Natural Science Foundation of China (31528016, 31371449 and 31671558). The authors have no competing interests.

Development and characterization of a novel long-acting recombinant follicle stimulating hormone agonist by fusing Fc to an FSH-ß subunit.

STUDY QUESTION: Does a novel long-acting recombinant human FSH, KN015, a heterodimer composed of FSHα and FSHß-Fc/Fc, offer a potential FSH alternative? SUMMARY ANSWER: KN015 had in vitro activity and superior in vivo bioactivity than recombinant human FSH (rhFSH), suggesting KN015 could serve as a potential FSH agonist for clinical therapy. WHAT IS KNOWN ALREADY: rhFSH has very short half-life so that repeat injections are needed, resulting in discomfort and inconvenience for patients. The longest-acting rhFSH available in clinics is corifollitropin alpha (FSH-CTP), but its half-life is not long enough to sustain the whole therapy period, and additional injections of rhFSH are needed. STUDY DESIGN, SIZE, DURATION: Plasmids containing FSHα, FSHß-Fc and Fc cDNA were transfected into Chinese hamster ovary (CHO) cells for KN015 production. The pharmacokinetics of KN015 was investigated in 6-week-old SD rats (n = 6/group) and healthy Cynomolgus monkeys in two different dose groups (n = 2/group). A series of experiments were designed for in vitro and in vivo characterization of the bioactivity of KN015 relative to rhFSH. PARTICIPANTS/MATERIALS, SETTING, METHODS: The purity and molecular weight of KN015 were determined by reducing and non-reducing SDS-PAGE. To measure KN015 half-life, sera were collected at increasing time points and the remaining FSH concentration was measured by enzyme-linked immunosorbent assay. To assess the bioactivity of KN015 versus rhFSH in vitro, firstly cAMP production was assessed in CHO cells expressing FSH receptor (FSHR) with the treatment of Fc/Fc, rhFSH or KN015 at eight different doses (0.03, 0.09, 0.28, 0.83, 2.5, 7.5, 22.5, 67.5 nM), and secondly cumulus oocyte complexes (COCs; n = 20/group) of ICR mice (primed-PMSG 44 h before sacrificed) were collected and cultured in medium containing 1.25 pM Fc/Fc, rhFSH or KN015 at 37°C and then germinal vesicle breakdown (GVBD) and COC expansion were observed at 4 and 16 h, respectively. The in vivo activity of KN015 was compared with rhFSH by ovary weight gain and ovulation assays. In the former, ovary weight gains in 21-day-old female SD rats, after a single subcutaneous injection of KN015, were compared with those after several injections of rhFSH over a range of doses (n = 8/group). Sera were harvested for estradiol (E2) analysis, and the ovaries were processed for hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labeling (TUNEL), RT-PCR and western blot. In the latter, 26-day-old female SD rats (n = 8/group) were injected with different doses of KN015 or rhFSH, and were sacrificed at 24 h after an injection of hCG (20 IU/rat). Moreover, the molecular responses stimulated by KN015 or rhFSH in the ovary were also analyzed through detecting expression of the FSH target genes (Cyp19a1, Fshr and Lhcgr) and phosphatidylinositide 3-kinase (PI3K) pathway activation. MAIN RESULTS AND THE ROLE OF CHANCE: KN015 has a molecular weight of 82 kD and its half-life is 84 h in SD rats (10-fold longer than that of rhFSH) and 215 h in Cynomolgus monkeys. The EC50 value of the cAMP induction in CHO cells (KN015 versus rhFSH, 1.84 versus 0.87 nM), COC expansion and oocyte maturation assays showed KN015 had approximately half of rhFSH's activity in vitro. A single dose of KN015 (1.5 pmol/rat, 166.1 ± 19.7 mg, P < 0.01) stimulated significantly larger ovary weight gain than several injections of rhFSH (1.5 pmol/rat, 59.3 ± 28.1 mg, P < 0.01). The serum E2 level in the KN015 group was significantly higher than that in rhFSH group. The number of oocytes obtained by ovulation induction was comparable with or higher in the KN015 group than in the rhFSH group. KN015 was more effective than rhFSH in inducing FSH target genes (Cyp19a1, Fshr, Lhcgr) or activating the PI3K pathway in vivo. Moreover, a single injection of KN015 promoted granulosa cell proliferation and prevented follicle atresia to the same extent as several injections of rhFSH. LIMITATIONS, REASONS FOR CAUTION: All assays in this study were operated only in animals and clinical trials are needed to confirm they can be extrapolated to humans. WIDER IMPLICATIONS OF THE FINDINGS: KN015 is a valuable alternative to FSH and may have great potential for therapeutic applications. STUDY FUNDING/COMPETING INTERESTS: This study was supported by National Basic Research Program of China (2011|CB944504, 2012CB944403) and National Natural Science Foundation of China (81172473, 31371449). The authors have no conflicts of interest to declare.

CBP-CITED4 is required for luteinizing hormone-triggered target gene expression during ovulation.

Pituitary-secreted luteinizing hormone (LH) induces ovulation by activating an extracellular regulated kinase 1/2 (ERK1/2) cascade. However, little is known regarding the ERK1/2 downstream effectors that are involved in regulating rapid, transient expression of LH-target gene in ovulatory follicles. By comparing the gene expression profiles of LH-stimulated wild type with ERK1/2-deleted ovarian granulosa cells (GCs), we identified Cited4 as a previously unknown LH target gene during ovulation. LH induced Cited4 expression in pre-ovulatory follicles in an ERK1/2-dependent manner. CITED4 formed an endogenous protein complex and docked on the promoters of LH and ERK1/2 target genes. Both CITED4 expression and CBP acetyltransferase activity leading to histone acetylation were indispensable for LH-induced ovulation-related events. LH induced dynamic histone acetylation changes in pre-ovulatory GCs, including the acetylation of histone H2B (Lys5) and H3 (Lys9). This was essential for the rapid responses and dramatic increases of LH target gene expressions by the ordered activation of ERK1/2 and CITED4-CBP. In addition, histone deacetylases (HDACs) antagonized CITED4-CBP to turn off expression of these genes after exposure to LH. Thus, we determined that CITED4 was a novel LH and ERK1/2 target for triggering ovulation. These results support the proposition that LH induces rapid, significant gene expression in pre-ovulatory follicles by modulating histone acetylation status.

DNA topoisomerase II is dispensable for oocyte meiotic resumption but is essential for meiotic chromosome condensation and separation in mice.

During mitosis, DNA topoisomerase II (TOP2) is required for sister chromatid separation. When TOP2 activity is inhibited, a decatenation checkpoint is activated by entangled chromatin. However, the functions of TOP2 in oocyte meiosis, particularly for homologous chromosome segregation during meiosis I, have not been investigated. In addition, it remains unknown if TOP2 inhibition activates a decatenation checkpoint at the G2/M transition in oocytes. In this study, we used mouse oocytes and specific inhibitors of TOP2 (ICRF-193 and etoposide) to investigate the role of TOP2 in meiosis. Our results indicated that an effective decatenation checkpoint did not exist in fully grown oocytes, as oocytes underwent the G2/M transition and reinitiated meiosis even when TOP2 activity was inhibited. However, oocytes treated with ICRF-193 had severe defects in chromosome condensation and homologous chromosome separation. Furthermore, condensed chromosomes failed to maintain their normal configurations in matured oocytes that were treated with ICRF-193. However, sister chromatid separation and subsequent chromosome decondensation during the exit from meiosis were not blocked by TOP2 inhibitors. These results indicated that TOP2 had a specific, crucial function in meiosis I. Thus, we identified important functions of TOP2 during oocyte maturation and provided novel insights into the decatenation checkpoint during meiosis.

Ovulatory signal-triggered chromatin remodeling in ovarian granulosa cells by HDAC2 phosphorylation activation-mediated histone deacetylation.

BACKGROUND: Epigenetic reprogramming is involved in luteinizing hormone (LH)-induced ovulation; however, the underlying mechanisms are largely unknown. RESULTS: We here observed a rapid histone deacetylation process between two waves of active transcription mediated by the follicle-stimulating hormone (FSH) and the LH congener human chorionic gonadotropin (hCG), respectively. Analysis of the genome-wide H3K27Ac distribution in hCG-treated granulosa cells revealed that a rapid wave of genome-wide histone deacetylation remodels the chromatin, followed by the establishment of specific histone acetylation for ovulation. HDAC2 phosphorylation activation coincides with histone deacetylation in mouse preovulatory follicles. When HDAC2 was silenced or inhibited, histone acetylation was retained, leading to reduced gene transcription, retarded cumulus expansion, and ovulation defect. HDAC2 phosphorylation was associated with CK2α nuclear translocation, and inhibition of CK2α attenuated HDAC2 phosphorylation, retarded H3K27 deacetylation, and inactivated the ERK1/2 signaling cascade. CONCLUSIONS: This study demonstrates that the ovulatory signal erases histone acetylation through activation of CK2α-mediated HDAC2 phosphorylation in granulosa cells, which is an essential prerequisite for subsequent successful ovulation.

HucMSC-EVs Facilitate In Vitro Development of Maternally Aged Preantral Follicles and Oocytes.

Follicle developmental capacity and oocyte quality decline with advanced maternal age. Extracellular vesicles from human umbilical cord mesenchymal stem cells (HucMSC-EVs) act as a potential therapeutic product in the treatment of age-related ovarian dysfunction. In vitro culture (IVC) of preantral follicles is a useful method for understanding the mechanism of follicle development and is a promising means for improving female fertility. However, whether HucMSC-EVs have beneficial effects on aged follicle development during IVC has not yet been reported. Our research demonstrated that follicular development with single-addition withdrawal of HucMSC-EVs was better than that with continuous treatment with HucMSC-EVs. HucMSC-EVs facilitated the survival and growth of follicles, promoted the proliferation of granulosa cells (GCs), and improved the steroid hormone secretion of GCs during IVC of aged follicles. Both GCs and oocytes could uptake HucMSC-EVs. Moreover, we observed elevated cellular transcription in GCs and oocytes after treatment with HucMSC-EVs. The RNA sequencing (RNA-seq) results further validated that the differentially expressed genes are related to the promotion of GC proliferation, cell communication, and oocyte spindle organization. Additionally, the aged oocytes displayed a higher maturation rate, presented less aberrant spindle morphology, and expressed a higher level of the antioxidant protein Sirtuin 1 (SIRT1) after treatment with HucMSC-EVs. Our findings suggested that HucMSC-EVs can improve the growth and quality of aged follicles and oocytes in vitro through the regulation of gene transcription, which provides evidence for HucMSC-EVs as potential therapeutic reagents to restore female fertility with advanced age.

[Expression and promotor methylation of p73 gene in ovarian epithelial tumors].

OBJECTIVE: To investigate the expression and promoter methylation status of p73 gene in ovarian epithelial tumors and their clinicopathological correlations. METHODS: Tissue microarrays (TMA) consisting of 68 ovarian cancers, 37 ovarian borderline tumors and 21 ovarian benign tumors were constructed. p73 expression was detected by immunohistochemistry (EnVision method). Fresh-frozen tissue samples from 13 cases of ovarian carcinomas and 5 cases of borderline tumors were evaluated for the presence of p73 promoter methylation using bisulfite sequencing. RESULTS: Overall, 92.6% (63/68) ovarian carcinomas expressed p73, with a mean value of 32% (percentage of p73 positive cells in the tumor). The mean value of p73 expression rate (40%) in serous carcinoma (26/26) was higher than those of other cancer types (P = 0.006). The mean value of p73 expression rate (40%) in type II ovarian carcinoma was significantly higher than that in type I ovarian carcinoma (24%, P = 0.010). The expression of p73 was not associated with FIGO stage and histological grade (both P > 0.05). The mean values of p73 expression in ovarian borderline tumor (30/37) and benign tumor (12/21) were 16% and 15%, respectively. Of the two groups, the mean value of p73 expression rate in serous type was higher than that in mucous type (P = 0.003, P = 0.026). Ovarian carcinomas had a higher level of p73 expression than borderline tumors and benign tumors (both P < 0.05), while that between ovarian borderline tumors and benign tumors had no statistical difference (P > 0.05). Among serous tumors (49/53), the mean value of p73 expression in the carcinoma group (26/26) was significantly higher than those in the borderline tumor group (12/14) and benign tumor group (11/13; P = 0.024 and P = 0.002, respectively), while that between borderline tumor group and benign tumor group had no statistical difference (P = 0.428). Among mucous tumors (15/27), the mean value of p73 expression in carcinoma group (6/7) was higher than that in benign tumor group (1/8; P = 0.032). No statistical difference of p73 expression was seen between the carcinoma group and ovarian borderline tumor group (8/12) and between the borderline tumor group and benign tumor group (P = 0.234, P = 0.201, respectively). p73 promotor methylation was found in 8 of 13 cases of carcinomas but at different methylation levels with a mean value of 8.0%. Two of 5 ovarian borderline tumors showed detectable p73 promotor methylation with a mean value of 9.0%. Compared with the borderline tumors, ovarian carcinomas showed a similar p73 methylation level (P > 0.05). The p73 methylation level in ovarian carcinomas was not associated with histological type, pathogenetic type, histological grade and FIGO stage (all P > 0.05). CONCLUSIONS: Most of ovarian epithelial tumors express p73 protein with mean values higher in ovarian carcinomas than those in the borderline and benign tumors. Ovarian serous carcinomas have the highest expression level of p73. A simple linear correlation does not exist between the promoter methylation and protein expression of p73.