Hippo signaling in the ovary and polycystic ovarian syndrome

Luteolin and its analog luteolin-7-methylether from Leonurus japonicus Houtt suppress aromatase-mediated estrogen biosynthesis to alleviate polycystic ovary syndrome by the inhibition of tumor progression locus 2

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus japonicus Houtt (L. japonicus, Chinese motherwort), known as Yi Mu Cao which means "good for women", has long been widely used in China and other Asian countries to alleviate gynecological disorders, often characterized by estrogen dysregulation. It has been used for the treatment of polycystic ovary syndrome (PCOS), a common endocrine disorder in women but the underlying mechanism remains unknown.

AIM OF THE STUDY

The present study was designed to investigate the effect and mechanism of flavonoid luteolin and its analog luteolin-7-methylether contained in L. japonicus on aromatase, a rate-limiting enzyme that catalyzes the conversion of androgens to estrogens and a drug target to induce ovulation in PCOS patients.

MATERIALS AND METHODS

Estrogen biosynthesis in human ovarian granulosa cells was examined using ELISA. Western blots were used to explore the signaling pathways in the regulation of aromatase expression. Transcriptomic analysis was conducted to elucidate the potential mechanisms of action of compounds. Finally, animal models were used to assess the therapeutic potential of these compounds in PCOS.

RESULTS

Luteolin potently inhibited estrogen biosynthesis in human ovarian granulosa cells stimulated by follicle-stimulating hormone. This effect was achieved by decreasing cAMP response element-binding protein (CREB)-mediated expression of aromatase. Mechanistically, luteolin and luteolin-7-methylether targeted tumor progression locus 2 (TPL2) to suppress mitogen-activated protein kinase 3/6 (MKK3/6)-p38 MAPK-CREB pathway signaling. Transcriptional analysis showed that these compounds regulated the expression of different genes, with the MAPK signaling pathway being the most significantly affected. Furthermore, luteolin and luteolin-7-methylether effectively alleviated the symptoms of PCOS in mice.

CONCLUSIONS

This study demonstrates a previously unrecognized role of TPL2 in estrogen biosynthesis and suggests that luteolin and luteolin-7-methylether have potential as novel therapeutic agents for the treatment of PCOS. The results provide a foundation for further development of these compounds as effective and safe therapies for women with PCOS.

Susceptibility loci identified in Han Chinese influence genetic predisposition of PCOS in Indian women

BACKGROUND

Polycystic ovary syndrome (PCOS) is a multifactorial disorder characterized by a broad spectrum of reproductive and metabolic perturbations, necessitating early timely diagnosis and management. PCOS is a multigenic disorder and ample evidence from family based, candidate gene and genome-wide association studies (GWAS) has implicated genetic factors in development and progression of PCOS. The first GWASs in Han Chinese population revealed prominent gene loci to be strong contenders in the etiopathogenesis of PCOS. However, different ethnic and geographical settings impact the genetic association pattern of PCOS.

METHODS AND RESULTS

In the current case-control replication study, we have genotyped previously identified polymorphisms viz. rs2479106 and rs10818854 of DENND1A and rs13405728 of LHCGR, rs4385527 and rs3802457 of c9orf3, rs705702 of RAB5B and rs1894116 of YAP1 in control (N = 247) and PCOS (N = 504) women by Sanger sequencing, and their association with PCOS susceptibility and its related traits was investigated. We found significant association of rs4385527 of c9orf3 and rs1894116 of YAP1 with decreased and increased PCOS susceptibility respectively in non-hyperandrogenic women. Trend towards association was also noted for rs2479106 of DENND1A and rs705702 of RAB5B. Additionally, polymorphisms also showed association with metabolic and androgen related traits in both controls and hyper- and non-hyperandrogenic women with PCOS.

CONCLUSIONS

Thus, this study shows that some, but not all polymorphisms previously identified in Han Chinese women, could contribute to the genetic pathophysiology of PCOS in Indian women, accentuating essentiality of conducting replication studies to elucidate the genetic predisposition profile of PCOS.

Signaling pathways and targeted therapeutic strategies for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. Although promising strides have been made in the field of PCOS over the past decades, the distinct etiologies of this syndrome are not fully elucidated. Prenatal factors, genetic variation, epigenetic mechanisms, unhealthy lifestyles, and environmental toxins all contribute to the development of this intricate and highly heterogeneous metabolic, endocrine, reproductive, and psychological disorder. Moreover, interactions between androgen excess, insulin resistance, disruption to the hypothalamic-pituitary-ovary (HPO) axis, and obesity only make for a more complex picture. In this review, we investigate and summarize the related molecular mechanisms underlying PCOS pathogenesis from the perspective of the level of signaling pathways, including PI3K/Akt, TGF-β/Smads, Wnt/β-catenin, and Hippo/YAP. Additionally, this review provides an overview of prospective therapies, such as exosome therapy, gene therapy, and drugs based on traditional Chinese medicine (TCM) and natural compounds. By targeting these aberrant pathways, these interventions primarily alleviate inflammation, insulin resistance, androgen excess, and ovarian fibrosis, which are typical symptoms of PCOS. Overall, we hope that this paper will pave the way for better understanding and management of PCOS in the future.

Making a good egg: human oocyte health, aging, and in vitro development

Mammalian eggs (oocytes) are formed during fetal life and establish associations with somatic cells to form primordial follicles that create a store of germ cells (the primordial pool). The size of this pool is influenced by key events during the formation of germ cells and by factors that influence the subsequent activation of follicle growth. These regulatory pathways must ensure that the reserve of oocytes within primordial follicles in humans lasts for up to 50 years, yet only approximately 0.1% will ever be ovulated with the rest undergoing degeneration. This review outlines the mechanisms and regulatory pathways that govern the processes of oocyte and follicle formation and later growth, within the ovarian stroma, through to ovulation with particular reference to human oocytes/follicles. In addition, the effects of aging on female reproductive capacity through changes in oocyte number and quality are emphasized, with both the cellular mechanisms and clinical implications discussed. Finally, the details of current developments in culture systems that support all stages of follicle growth to generate mature oocytes in vitro and emerging prospects for making new oocytes from stem cells are outlined.

The mechanisms crosstalk and therapeutic opportunities between ferroptosis and ovary diseases

Ferroptosis, a form of regulated cell death, was first defined in 2012. Ferroptosis mainly involves iron-driven lipid peroxidation damage of cells. This process is regulated by iron homeostasis, redox balance, lipid metabolism, glutathione metabolism, and various disease signaling pathways. Iron is one of the key mineral elements that regulate the physiological function of women and the development of ovarian tumors. Occurrence of Ferroptosis has some hidden dangers and advantages in ovary diseases. Some scholars have shown that ferroptosis of ovarian granulosa cells (GC) promotes the development of ovarian dysfunction and polycystic ovary syndrome (PCOS). Interestingly, drug-resistant ovarian cancer cells are very sensitive to ferroptosis, suggesting that pharmacological positive and negative regulation of ferroptosis has great potential in the treatment of benign ovarian diseases and ovarian cancer. This article aimed to assess how ferroptosis occurs and the factors controlling ferroptosis. Moreover, we summarize how ferroptosis can be used to predict, diagnose and target treatment ovary disease. Meanwhile, we also evaluated the different phenomena of Ferroptosis in ovarian diseases. It aims to provide new directions for the research and prevention of female reproductive diseases.

Altered m6A modification is involved YAP-mediated apoptosis response in 4-vinylcyclohexene diepoxide induced ovotoxicity

4-Vinylcyclohexene diepoxide (VCD), an industrial occupational health hazard chemical associated with premature ovarian insufficiency (POI) and reproductive failure. Recently, investigators have paid an increasing attention on VCD model of menopause recapitulates the natural, physiological transition through perimenopause to menopause. The current study sought to examining the mechanisms of follicular loss and exploring the effect of the model on systems outside of the ovaries. In this study, 28 days female SD rats were injected with VCD (160 mg/kg) vehicle for 15 consecutive days, euthanized in the diestrus phase approximately 100 days after the onset of treatment. Reproductive system injury, Neuroendocrine, sex hormone levels and receptor were observed, the levels of N6-methyladenosine (m6A) RNA modification and the expression of modulator genes were first measured. The VCD treated rats showing irregular estrous cycles, significantly reduced in the number of primordial follicles, the preantral and antral follicles also decreased significantly, accompanied by the plasma level of FSH increased and anti-Mullerian hormone (AMH) were decreased. The total m6A level was significantly decreased after exposure to VCD. Moreover, ALKBH5-mediated YAP m6A modification changed in VCD - induced premature ovarian insufficiency. These present work provides a new perspective on m6A modification in the VCD-induced POI rat model, which could provide valuable insights into the mechanisms underlying follicle development and finding new therapeutic targets for follicle prematurely exhausted. Also provide novel methodological guidance and endocrine basis to guide research and extend the applications in premature ovarian insufficiency model.

Multi-omics insights and therapeutic implications in polycystic ovary syndrome: a review

Polycystic ovary syndrome (PCOS) is a common gynecological disease that causes adverse effects in women in their reproductive phase. Nonetheless, the molecular mechanisms remain unclear. Over the last decade, sequencing and omics approaches have advanced at an increased pace. Omics initiatives have come to the forefront of biomedical research by presenting the significance of biological functions and processes. Thus, multi-omics profiling has yielded important insights into understanding the biology of PCOS by identifying potential biomarkers and therapeutic targets. Multi-omics platforms provide high-throughput data to leverage the molecular mechanisms and pathways involving genetic alteration, epigenetic regulation, transcriptional regulation, protein interaction, and metabolic alterations in PCOS. The purpose of this review is to outline the prospects of multi-omics technologies in PCOS research by revealing novel biomarkers and therapeutic targets. Finally, we address the knowledge gaps and emerging treatment strategies for the management of PCOS. Future PCOS research in multi-omics at the single-cell level may enhance diagnostic and treatment options.

n-3 PUFA Promotes Ferroptosis in PCOS GCs by Inhibiting YAP1 through Activation of the Hippo Pathway

Polycystic ovary syndrome (PCOS) is an endocrine disorder characterized by hyperandrogenemia with multiple suspended sinus follicles, thickened cortical tissue, and excessive proliferation of ovarian granulosa cells that severely affects the fertility and quality of life of women. The addition of n-3 PUFA to the diet may slightly reduce body weight and greatly alleviate disturbed blood hormone levels in PCOS mice. We treated KGN as a cell model for n-3 PUFA addition and showed that n-3 PUFA inhibited the proliferation of GCs and promoted ferroptosis in ovarian granulosa cells. We used CCK-8, fluorescence quantitative transmission electron microscopy experiments and ferroptosis marker gene detection and other methods. Furthermore, n-3 PUFA was found to promote YAP1 exocytosis by activating Hippo and weakening the cross-talk between YAP1 and Nrf2 by activating the Hippo signaling pathway. In this study, we found that n-3 PUFA inhibited the over proliferation of granulosa cells in ovarian follicles by activating Hippo, promoting YAP1 exocytosis, weakening the cross-talk between YAP1 and Nrf2, and ultimately activating the ferroptosis sensitivity of ovarian granulosa cells. We demonstrate that n-3 PUFA can alleviate the hormonal and estrous cycle disorder with PCOS by inhibiting the YAP1-Nrf2 crosstalk that suppresses over proliferating ovarian granulosa cells and promotes iron death in GCs. These findings reveal the molecular mechanisms by which n-3 PUFA attenuates PCOS and identify YAP1-Nrf2 as a potential therapeutic target for regulation granulosa cells in PCOS.

Therapeutic Effect of Melatonin in Premature Ovarian Insufficiency: Hippo Pathway Is Involved

Objective

Premature ovarian insufficiency (POI) is a female reproductive disorder of unknown etiology with no definite pathogenesis. Melatonin (MT) is an endogenous hormone synthesized mainly by pineal cells and has strong endogenous effects in regulating ovarian function. To systematically explore the pharmacological mechanism of MT on POI therapy, a literature review approach was conducted at the signaling pathways level.

Methods

Relevant literatures were searched and downloaded from databases, including PubMed and China National Knowledge Infrastructure, using the keywords “premature ovarian insufficiency,” “Hippo signaling pathways,” and “melatonin.” The search criteria were from 2010 to 2022. Text mining was also performed.

Results

MT is involved in the regulation of Hippo signaling pathway in a variety of modes and has been correlated with ovarian function.

Conclusions

The purpose of this review is to summarize the research progress of Hippo signaling pathways and significance of MT in POI, the potential crosstalk between MT and Hippo signaling pathways, and the prospective therapy.

Biomechanical characteristics of the ovarian cortex in POI patients and functional outcomes after drug-free IVA

PURPOSE

There is increasing evidence that the ovarian extracellular matrix (ECM) plays a critical role in follicle development. The rigidity of the cortical ECM limits expansion of the follicle and consequently oocyte maturation, maintaining the follicle in its quiescent state. Quiescent primordial, primary, and secondary follicles still exist in primary ovarian insufficiency (POI) patients, and techniques as in vitro activation (IVA) and drug-free IVA have recently been developed aiming to activate these follicles based on the Hippo signaling disruption that is essential in mechanotransduction. In this context, we analyze the effect of drug-free IVA in POI patients, comparing the relationship between possible resumption ovarian function and biomechanical properties of ovarian tissue.

METHODS

Nineteen POI patients according to ESHRE criteria who underwent drug-free IVA by laparoscopy between January 2018 and December 2019 and were followed up for a year after the intervention. A sample of ovarian cortex taken during the intervention was analyzed by atomic force microscopy (AFM) in order to quantitatively measure tissue stiffness (Young's elastic modulus, E) at the micrometer scale. Functional outcomes after drug-free were analyzed.

RESULTS

Resumption of ovarian function was observed in 10 patients (52.6%) and two of them became pregnant with live births. There were no differences in clinical characteristics (age and duration of amenorrhea) and basal hormone parameters (FSH and AMH) depending on whether or not there was activation after surgery. However, ovarian cortex stiffness was significantly greater in patients with ovarian activity after drug-free IVA: median E = 5519 Pa (2260-11,296) vs 1501 (999-3474); p-value < 0.001.

CONCLUSIONS

Biomechanical properties of ovarian cortex in POI patients have a great variability, and higher ovarian tissue stiffness entails a more favorable status when drug-free IVA is applied in their treatment. This status is probably related to an ovary with more residual follicles, which would explain a greater possibility of ovarian follicular reactivations after treatment.

Perfluorooctanoic acid promotes proliferation of the human granulosa cell line HGrC1 and alters expression of cell cycle genes and Hippo pathway effector YAP1

Perfluorooctanoic acid (PFOA) is a common environmental contaminant that belongs to a group of manmade fluorinated chemicals called per- and polyfluoroalkyl substances (PFAS). Due to the pervasive nature of PFOA, the environmental health risks of PFOA contamination and exposure on reproductive health have increasing concern. In the present study, we exposed HGrC1 cells, an immortalized human granulosa cell line, to environmentally relevant (1-10 μM) concentrations of PFOA. Results indicated that HGrC1 cells treated with PFOA had increased proliferation and migration relative to vehicle treated controls. No differences in cell apoptosis were observed with 1-10 μM PFOA. Gene expression analysis revealed increases in mRNA transcripts for cell cycle regulators CCND1, CCNA2, and CCNB1. Upregulation of YAP1 protein and downstream target CTGF protein was also observed, suggesting that the Hippo pathway is involved in the proliferation and migratory effects of PFOA on HGrC1 cells. Further, the YAP1 inhibitor Verteporfin prevented the stimulatory effects of PFOA on HGrC1 cells. Together, these findings support a role for the Hippo pathway effector YAP1 in response to PFOA exposure in human granulosa cells.

Genetic Basis of Follicle Development in Dazu Black Goat by Whole-Transcriptome Sequencing

Simple Summary

The follicle development (FD) of a goat is precisely regulated by various noncoding RNAs (ncRNAs), especially by the regulatory mechanism of competing endogenous RNAs (ceRNAs). This study aimed to determine the expression patterns of messenger RNA (mRNA), long noncoding RNA, microRNA, and circular RNA during the FD of Dazhu black goats by whole-transcriptomic sequencing and analyze the regulatory mechanism of the ncRNA and ceRNA regulatory network. The results may lay a foundation for further research on FD and improving the reproductive performance of goats.

Abstract

The follicle development (FD) is an important factor determining litter size in animals. Recent studies have found that noncoding RNAs (ncRNAs) play an important role in FD. In particular, the role of the regulatory mechanism of competing endogenous RNAs (ceRNAs) that drive FD has attracted increasing attention. Therefore, this study explored the genetic basis of goat FD by obtaining the complete follicular transcriptome of Dazu black goats at different developmental stages. Results revealed that 128 messenger RNAs (mRNAs), 4 long noncoding RNAs (lncRNAs), 49 microRNAs (miRNAs), and 290 circular RNAs (circRNAs) were significantly differentially expressed (DE) between large and small follicles. Moreover, DEmRNAs were enriched in many signaling pathways related to FD, as well as GO terms related to molecular binding and enzyme activity. Based on the analysis of the ceRNA network (CRN), 34 nodes (1 DElncRNAs, 10 DEcircRNAs, 14 DEmiRNAs, and 9 DEmRNAs) and 35 interactions (17 DEcircRNAs–DEmRNAs, 2 DElncRNAs–DEmiRNAs, and 16 DEmRNA–DEmiRNAs) implied that the CRN could be involved in the FD of goats. In conclusion, we described gene regulation by DERNAs and lncRNA/circRNA–miRNA–mRNA CRNs in the FD of goats. This study provided insights into the genetic basis of FD in precise transcriptional regulation.

Pathogenetic analysis of polycystic ovary syndrome from the perspective of omics

Polycystic ovary syndrome (PCOS) is the most common gynecological endocrine disease, involving multiple genes, multiple pathways, and complex hormone secretion processes. Hence, the pathogenesis of PCOS cannot be explained by a single factor. Omics analysis includes genomics, transcriptomics, and proteomics, which are fast and effective methods for studying the pathogenesis of diseases. PCOS is primarily characterized by androgen excess, and reproductive and metabolic dysfunctions. The application of omics analysis in the body fluids, blood, cells or tissues of women with PCOS offers the potential for unexpected molecular advantages in explaining new mechanisms of PCOS etiology and pathophysiology, and provides new perspectives for identifying potential biomarkers and developing new therapeutic targets. At present, several omics analyses have been applied to produce complex datasets. In this manuscript, the recent advances in omics research on PCOS are summarized, aiming at an important and parallel review of the newly published research.

Endocrinological and ovarian histological investigations in assigned female at birth transgender people undergoing testosterone therapy

RESEARCH QUESTION

What are the hormonal and ovarian histological effects of a gender affirming hormonal therapy in assigned female at birth (AFAB) transgender people?

DESIGN

Prospective observational study of 70 AFAB transgender people taking testosterone therapy before gender-affirming surgery (hystero-oophorectomy). A gynaecological ultrasonographic scan was undertaken and serum hormone concentrations measured, including anti-Müllerian hormone (AMH) and androgenic profile. Histological ovarian evaluation was assessed in both ovaries, including the developmental stages of the follicles.

RESULTS

The mean age of the population was 27.7+/-5.14 years. The main biochemical parameters were total testosterone levels 781.5 ± 325.9 ng/dl; AMH levels 3.2 ± 1.4 ng/ml; FSH and LH levels 4.9 ± 2.5 IU/l and 3.9 ± 2.9 IU/l, respectively; and oestradiol values 47.6 ± 13.7 pg/ml. Fifty-five AFAB underwent gynaecological ultrasound before surgery and antral follicles were found in 43 out of 47 ultrasounds (91.5%) (without the presence of a dominant follicle or corpus luteum). Histological follicles were mostly in the primordial stage (88.0) and 3.3% were atretic. The thickness of the tunica albuginea was widely heterogeneous (range 0.15-1.45 mm) and luteinization of the stromal cells was observed in 68.6% of the samples. A negative correlation between testosterone levels and total antral follicles was found (R_s= -0.306, P = 0.029).

CONCLUSIONS

AFAB transgender people taking testosterone therapy show cortical follicle distribution in the range previously reported in fertile cisgender women of reproductive age. The follicular population may not be altered as a result of the gender-affirming hormonal therapy, although some cortical and stromal changes have been observed.

Human Mesenchymal Stem Cell Therapy and Other Novel Treatment Approaches for Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition characterized by amenorrhea, hypergonadotropic hypogonadism, estrogen deficiency, and reduced follicle counts leading to infertility under the age of 40. POI occurs in approximately 1-3% of women in the general population. Evaluation is warranted when the diagnosis of POI is made to rule out underlying etiologies, which could be multifactorial. This review serves to cover the novel treatment approaches reported in the literature.

In Vitro Activation Early Follicles: From the Basic Science to the Clinical Perspectives

Development of early follicles, especially the activation of primordial follicles, is strictly modulated by a network of signaling pathways. Recent advance in ovarian physiology has been allowed the development of several therapies to improve reproductive outcomes by manipulating early folliculogenesis. Among these, in vitro activation (IVA) has been recently developed to extend the possibility of achieving genetically related offspring for patients with premature ovarian insufficiency and ovarian dysfunction. This method was established based on basic science studies of the intraovarian signaling pathways: the phosphoinositide 3-kinase (PI3K)/Akt and the Hippo signaling pathways. These two pathways were found to play crucial roles in folliculogenesis from the primordial follicle to the early antral follicle. Following the results of rodent experiments, IVA was implemented in clinical practice. There have been multiple recorded live births and ongoing pregnancies. Further investigations are essential to confirm the efficacy and safety of IVA before used widely in clinics. This review aimed to summarize the published literature on IVA and provide future perspectives for its improvement.

High throughput microRNAs sequencing profile of serum exosomes in women with and without polycystic ovarian syndrome

Background

Polycystic ovary syndrome (PCOS) is the most common type of endocrine disorder, affecting 5–11% of women of reproductive age worldwide. microRNAs (miRNAs) stably exist in circulating blood encapsulated in extracellular vesicles such as exosomes; therefore, serum miRNAs have the potential to serve as novel PCOS biomarkers.

Methods

To identify miRNA biomarkers that are associated with PCOS, we performed a comprehensive sequence-based characterization of the PCOS serum miRNA landscape. The serum exosomes were successfully isolated and characterized in a variety of ways. Next, sequence-based analysis was performed on serum exosomes to screen the differentially expressed miRNAs in women with and without PCOS.

Results

The sequence data revealed that the levels of 54 miRNAs significantly differed between PCOS patients and normal controls. The levels of these miRNAs were detected by RT-qPCR. The results show that hsa-miR-1299, hsa-miR-6818-5p hsa-miR-192-5p, and hsa-miR-145-5p are significantly differentially expressed in PCOS patients serum exosomes and identify these microRNAs as potential biomarkers for PCOS. Furthermore, Gene Ontology (GO) analyses and KEGG pathway analyses of the miRNA targets further allowed to explore the potential implication of the miRNAs in PCOS.

Conclusion

Our findings suggest that serum exosomal miRNAs serve important roles in PCOS and may be used as novel molecular biomarkers for clinical diagnosis.

Ovarian Fragmentation and AKT Stimulation for Expansion of Fertile Lifespan

Since the first baby was born after in vitro fertilization, the female infertility treatment has been well-developed, yielding successful outcomes. However, successful pregnancies for patients with premature ovarian insufficiency and diminished ovarian reserve are still difficult and diverse therapies have been suggested to improve the chances to have their genetically linked offspring. Recent studies demonstrated that the activation Akt pathway by using a phosphatase and tensin homolog enzyme inhibitor and a phosphatidylinositol-3 kinase stimulator can activate dormant primordial follicles in both mice and human ovaries. Subsequent researches suggested that the disruption of Hippo signaling pathway by ovarian fragmentation increased the expression of downstream growth factors and secondary follicle growth. Based on the combination of ovarian fragmentation and Akt stimulation, the in vitro activation (IVA) approach has resulted in successful follicle growth and live births in premature ovarian insufficiency patients. The approach with disruption of Hippo signaling only was also shown to be effective for treating poor ovarian responders with diminishing ovarian reserve, including advanced age women and cancer patients undergoing sterilizing treatments. This review aims to summarize the effectiveness of ovarian fragmentation and Akt stimulation on follicle growth and the potential of IVA in extending female fertile lifespan.

KLF4 initiates sustained YAP activation to promote renal fibrosis in mice after ischemia-reperfusion kidney injury

Acute renal injury (AKI) causes a long-term risk for progressing into chronic kidney disease (CKD) and interstitial fibrosis. Yes-associated protein (YAP), a key transcriptional cofactor in Hippo signaling pathway, shuttles between the cytoplasm and nucleus, which is required for the renal tubular epithelial cells repair in the acute phase of AKI. In this study we investigated the role of YAP during ischemia-reperfusion (IR)-induced AKI to CKD. Mice were subjected to left kidney IR followed by removal of the right kidney on the day before tissue harvests. Mouse shRNA expression adenovirus (Ad-shYAP or Ad-shKLF4) and mouse KLF4 expression adenovirus (Ad-KLF4) were delivered to mice by intrarenal injection on D7 after IR. We showed that the expression and nucleus distribution of YAP were persistently increased until the end of experiment (D21 after IR). The sustained activation of YAP in post-acute phase of AKI was accompanied by renal dysfunction and interstitial fibrosis. Knockdown of YAP significantly attenuated IR-induced renal dysfunction and decreased the expression of fibrogenic factors TGF-β and CTGF in the kidney. We showed that the expression of the transcription factor KLF4, lined on the upstream of YAP, was also persistently increased. Knockdown on KLF4 attenuated YAP increase and nuclear translocation as well as renal functional deterioration and interstitial fibrosis in IR mice, whereas KLF4 overexpression caused opposite effects. KLF4 increased the expression of ITCH, and ITCH facilitated YAP nuclear translocation via degrading LATS1. Furthermore, we demonstrated in primary cultured renal tubular cells that KLF4 bound to the promoter region of YAP and positively regulates YAP expression. In biopsy sample from CKD patients, we also observed increased expression and nuclear distribution of YAP. In conclusion, the activation of YAP in the post-acute phase of AKI is implicated in renal functional deterioration and fibrosis although it exhibits beneficial effect in acute phase. Reprogramming factor KLF4 is responsible for the persistent activation of YAP. Blocking the activation of KLF4-YAP pathway might be a way to prevent the transition of AKI into CKD.

Interplay Between mTOR and Hippo Signaling in the Ovary: Clinical Choice Guidance Between Different Gonadotropin Preparations for Better IVF

One of the most widely used types of assisted reproduction technology is the in vitro fertilization (IVF), in which women undergo controlled ovarian stimulation through the administration of the appropriate hormones to produce as many mature follicles, as possible. The most common hormone combination is the co-administration of gonadotropin-releasing hormone (GnRH) analogues with recombinant or urinary-derived follicle-stimulating hormone (FSH). In the last few years, scientists have begun to explore the effect that different gonadotropin preparations have on granulosa cells' maturation and apoptosis, aiming to identify new predictive markers of oocyte quality and successful fertilization. Two major pathways that control the ovarian development, as well as the oocyte-granulosa cell communication and the follicular growth, are the PI3K/Akt/mTOR and the Hippo signaling. The purpose of this article is to briefly review the current knowledge about the effects that the different gonadotropins, used for ovulation induction, may exert in the biology of granulosa cells, focusing on the importance of these two pathways, which are crucial for follicular maturation. We believe that a better understanding of the influence that the various ovarian stimulation protocols have on these critical molecular cascades will be invaluable in choosing the best approach for a given patient, thereby avoiding cancelled cycles, reducing frustration and potential treatment-related complications, and increasing the pregnancy rate. Moreover, individualizing the treatment plan will help clinicians to better coordinate assisted reproductive technology (ART) programs, discuss the specific options with the couples undergoing IVF, and alleviate stress, thus making the IVF experience easier.

Implications of Nonphysiological Ovarian Primordial Follicle Activation for Fertility Preservation

In recent years, ovarian tissue cryopreservation has rapidly developed as a successful method for preserving the fertility of girls and young women with cancer or benign conditions requiring gonadotoxic therapy, and is now becoming widely recognized as an effective alternative to oocyte and embryo freezing when not feasible. Primordial follicles are the most abundant population of follicles in the ovary, and their relatively quiescent metabolism makes them more resistant to cryoinjury. This dormant pool represents a key target for fertility preservation strategies as a resource for generating high-quality oocytes. However, development of mature, competent oocytes derived from primordial follicles is challenging, particularly in larger mammals. One of the main barriers is the substantial knowledge gap regarding the regulation of the balance between dormancy and activation of primordial follicles to initiate their growing phase. In addition, experimental and clinical factors also affect dormant follicle demise, while the mechanisms involved remain largely to be elucidated. Moreover, most of our basic knowledge of these processes comes from rodent studies and should be extrapolated to humans with caution, considering the differences between species in the reproductive field. Overcoming these obstacles is essential to improving both the quantity and the quality of mature oocytes available for further fertilization, and may have valuable biological and clinical applications, especially in fertility preservation procedures. This review provides an update on current knowledge of mammalian primordial follicle activation under both physiological and nonphysiological conditions, and discusses implications for fertility preservation and priorities for future research.

A genome-wide association study of polycystic ovary syndrome identified from electronic health records

BACKGROUND

Polycystic ovary syndrome is the most common endocrine disorder affecting women of reproductive age. A number of criteria have been developed for clinical diagnosis of polycystic ovary syndrome, with the Rotterdam criteria being the most inclusive. Evidence suggests that polycystic ovary syndrome is significantly heritable, and previous studies have identified genetic variants associated with polycystic ovary syndrome diagnosed using different criteria. The widely adopted electronic health record system provides an opportunity to identify patients with polycystic ovary syndrome using the Rotterdam criteria for genetic studies.

OBJECTIVE

To identify novel associated genetic variants under the same phenotype definition, we extracted polycystic ovary syndrome cases and unaffected controls based on the Rotterdam criteria from the electronic health records and performed a discovery-validation genome-wide association study.

STUDY DESIGN

We developed a polycystic ovary syndrome phenotyping algorithm on the basis of the Rotterdam criteria and applied it to 3 electronic health record-linked biobanks to identify cases and controls for genetic study. In the discovery phase, we performed an individual genome-wide association study using the Geisinger MyCode and the Electronic Medical Records and Genomics cohorts, which were then meta-analyzed. We attempted validation of the significant association loci (P<1×10^-6) in the BioVU cohort. All association analyses used logistic regression, assuming an additive genetic model, and adjusted for principal components to control for population stratification. An inverse-variance fixed-effect model was adopted for meta-analysis. In addition, we examined the top variants to evaluate their associations with each criterion in the phenotyping algorithm. We used the STRING database to characterize protein-protein interaction network.

RESULTS

Using the same algorithm based on the Rotterdam criteria, we identified 2995 patients with polycystic ovary syndrome and 53,599 population controls in total (2742 cases and 51,438 controls from the discovery phase; 253 cases and 2161 controls in the validation phase). We identified 1 novel genome-wide significant variant rs17186366 (odds ratio [OR]=1.37 [1.23, 1.54], P=2.8×10^-8) located near SOD2. In addition, 2 loci with suggestive association were also identified: rs113168128 (OR=1.72 [1.42, 2.10], P=5.2×10^-8), an intronic variant of ERBB4 that is independent from the previously published variants, and rs144248326 (OR=2.13 [1.52, 2.86], P=8.45×10^-7), a novel intronic variant in WWTR1. In the further association tests of the top 3 single-nucleotide polymorphisms with each criterion in the polycystic ovary syndrome algorithm, we found that rs17186366 (SOD2) was associated with polycystic ovaries and hyperandrogenism, whereas rs11316812 (ERBB4) and rs144248326 (WWTR1) were mainly associated with oligomenorrhea or infertility. We also validated the previously reported association with DENND1A1. Using the STRING database to characterize protein-protein interactions, we found both ERBB4 and WWTR1 can interact with YAP1, which has been previously associated with polycystic ovary syndrome.

CONCLUSION

Through a discovery-validation genome-wide association study on polycystic ovary syndrome identified from electronic health records using an algorithm based on Rotterdam criteria, we identified and validated a novel genome-wide significant association with a variant near SOD2. We also identified a novel independent variant within ERBB4 and a suggestive association with WWTR1. With previously identified polycystic ovary syndrome gene YAP1, the ERBB4-YAP1-WWTR1 network suggests involvement of the epidermal growth factor receptor and the Hippo pathway in the multifactorial etiology of polycystic ovary syndrome.

In Vitro Follicular Activation and Stem Cell Therapy as a Novel Treatment Strategies in Diminished Ovarian Reserve and Primary Ovarian Insufficiency

Usually poor ovarian response (POR) to gonadotropins reflects a diminished ovarian reserve (DOR) that gives place to few recruitable follicles despite aggressive stimulation. The reduction in the quantity and quality of the oocytes with advanced age is physiological. However, some women experience DOR much earlier and become prematurely infertile, producing an accelerated follicular depletion towards primary ovarian insufficiency (POI). Up to now, egg donation has been commonly used to treat their infertility. In the last thirty years, specialists in assisted reproduction have focused their attention on the final stages of folliculogenesis, those that depend on the action of gonadotrophins. Nevertheless, recently novel aspects have been known to act in the initial phases, with activating and inhibiting elements. In vitro activation (IVA) combining the in vitro stimulation of the ovarian Akt signaling pathway in ovarian cortex fragments with a method named Hippo-signaling disruption. Later, a simplification of the technique designated Drug-Free IVA have shown encouraging results in patients with POI. Another innovative therapeutic option in these patients is the infusion of bone marrow-derived stem cells (BMDSC) in order to supply an adequate ovarian niche to maintain and/or promote follicular rescue in patients with impaired or aged ovarian reserves. In this review, for the first time, both therapeutic options are addressed together in a common clinical setting. The aim of this review is to analyze the physiological aspects on which these innovative techniques are based; the preliminary results obtained up to now; and the possible therapeutic role that they may have in the future with DOR and POI patients.

Drug-free in-vitro activation of follicles and fresh tissue autotransplantation as a therapeutic option in patients with primary ovarian insufficiency

RESEARCH QUESTION

Could in-vitro action of follicles and fresh tissue autotransplantation without tissue culture (drug-free IVA) be useful in patients with primary ovarian insufficiency (POI)?

DESIGN

Prospective observational cohort study in a tertiary university hospital. Drug-Free IVA was carried out in 14 women with POI with a median age of 33 years (29-36 years), median length of amenorrhoea of 1.5 years (1-11 years), median FSH levels 69.2 mIU/ml (36.9-82.8 mIU/ml) and anti-Müllerian hormone of 0.02 ng/ml (0.01-0.1 ng/ml). The surgical procedure included laparoscopic removal of ovarian cortex, fragmentation of tissue and autografting. Human menopausal gonadotrophin (HMG) was started immediately after surgery.

RESULTS

Follicle development was detected in seven out of the 14 patients, and five women achieved successful oocyte retrieval. In six women, HCG was administered in 10 cycles. Six embryo transfers were carried out in five women resulting in four pregnancies; a clinical pregnancy rate of four in seven oocyte retrievals and four in six embryo transfers.

CONCLUSIONS

Drug-free IVA could be a useful therapeutic option for patients with POI, leading to successful IVF outcomes.

Identification of clinical trait-related lncRNA and mRNA biomarkers with weighted gene co-expression network analysis as useful tool for personalized medicine in ovarian cancer

RELEVANCE

The pathogenesis and biomarkers of ovarian cancer (OC) remain not well-known in diagnosis, effective therapy, and prognostic assessment in OC personalized medicine. The novel identified lncRNA and mRNA biomarkers from gene co-expression modules associated with clinical traits provide new insight for effective treatment of ovarian cancer.

PURPOSE

Long non-coding RNAs (lncRNAs) are relevant to tumorigenesis via multiple mechanisms. This study aimed to investigate cancer-specific lncRNAs and mRNAs, and their related networks in OCs.

METHODS

This study comprehensively analyzed lncRNAs and mRNAs with associated competing endogenous RNA (ceRNA) network and lncRNA-RNA binding protein-mRNA network in the OC tissues in the Cancer Genome Atlas, including 2562 cancer-specific lncRNAs (n = 352 OC tissues) and 5000 mRNAs (n = 359 OC tissues). The weighted gene co-expression network analysis (WGCNA) was used to construct the co-expression gene modules and their relationship with clinical traits. The statistically significant difference of identified lncRNAs and mRNAs was confirmed with qRT-PCR in OC cells.

RESULTS

An lncRNA-based co-expression module was significantly correlated with patient age at initial pathologic diagnosis, lymphatic invasion, tissues source site, and vascular invasion, and identified 16 lncRNAs (ACTA2-AS1, CARD8-AS1, HCP5, HHIP-AS1, HOTAIRM1, ITGB2-AS1, LINC00324, LINC00605, LINC01503, LINC01547, MIR31HG, MIR155HG, OTUD6B-AS1, PSMG3-AS1, SH3PXD2A-AS1, and ZBED5-AS1) that were significantly related to overall survival in OC patients. An mRNA-based co-expression module was significantly correlated with patient age at initial pathologic diagnosis, lymphatic invasion, tumor residual disease, and vascular invasion; and identified 21 hub-mRNA molecules and 11 mRNAs (FBN3, TCF7L1, SBK1, TRO, TUBB2B, PLCG1, KIAA1549, PHC1, DNMT3A, LAMA1, and C10orf82) that were closely linked with OC patients' overall survival. Moreover, the prognostic model of five-gene signature (OTUD6B-AS1, PSMG3-AS1, ZBED5-AS1, SBK1, and PLCG1) was constructed to predict risk score in OC patients. Furthermore, starBase bioinformatics constructed the lncRNA-miRNA-mRNA and lncRNA-RNA binding protein-mRNA networks in OCs.

CONCLUSION

These new findings showed that lncRNA-related networks in OCs are a useful resource for identification of biomarkers in OCs.