Project description:MicroRNAs (miRNAs) are short, noncoding RNAs that posttranscriptionally regulate gene expression. In the past decade, studies on miRNAs in ovaries have revealed the key roles of miRNAs in ovarian development and function. In this review, we first introduce the development of follicular atresia research and then summarize genome-wide studies on the ovarian miRNA profiles of different mammalian species. Differentially expressed miRNA profiles during atresia and other biological processes are herein compared. In addition, current knowledge on confirmed functional miRNAs during the follicular atresia process, which is mostly indicated by granulosa cell (GC) apoptosis, is presented. The main miRNA families and clusters, including the let-7 family, miR-23-27-24 cluster, miR-183-96-182 cluster and miR-17-92 cluster, and related pathways that are involved in follicular atresia are thoroughly summarized. A deep understanding of the roles of miRNA networks will not only help elucidate the mechanisms of GC apoptosis, follicular development, atresia and their disorders but also offer new diagnostic and treatment strategies for infertility and other ovarian dysfunctions.
Project description:BackgroundBoth mild and conventional controlled ovarian stimulation are the frequently used protocols for poor ovarian responders. However, there are some debates about which treatment is better. Moreover, little is known about the follicular physiology after the two ovarian stimulation protocols. This study was intended to investigate the features in granulosa cells and follicular fluid micro-environment after the two different ovarian stimulation protocols in poor responders.MethodsGranulosa cells RNA were sequenced using Illumina Hiseq technology. Specific differently expressed genes and proteins were verified by real-time quantitative PCR and Western blot analysis. Moreover, hormone and cytokine concentrations in the follicular fluid were measured by electrochemiluminescence immunoassay and enzyme-linked immunoabsorbent assay. The correlation between the results of molecular experiments and the laboratory outcomes were analyzed by Spearman correlation analysis.ResultsThe differentially expressed genes between the two groups were involved in 4 signaling pathways related to the follicular development; three proteins pertinent to the TGF-β signaling pathway were expressed differently in granulosa cells between the two, and the constituents in the follicular fluid were also different. Further, a correlation between the TGF-β signaling pathway and the good-quality embryo was observed.ConclusionsThe present study made a comparison for the first time in the transcriptome of human granulosa cells and the follicular fluid micro-environment between poor responders with the conventional controlled ovarian stimulation or the mild ovarian stimulation, showing that the TGF-β signaling pathway may correlate with the good-quality of embryos in the mild group, which may be instrumental to the choice of optimal management for IVF patients.
Project description:BackgroundPremature ovarian insufficiency (POI) refers to the severe decline or failure of ovarian function in women younger than 40 years of age. It is a serious hazard to women's physical and mental health, but current treatment options are limited. Mesenchymal stem cell-derived exosomes (MSC-Exo) exhibit promising potential as a therapeutic approach for POI. However, their clinical application is hindered by their instability and low long-term retention rate in vivo.Methods and resultsIn this study, miR-21 was identified as the predominant miRNA with low-expression in follicular fluid exosomes of POI patients and was shown to possess antiapoptotic activity. Next, we loaded miR-21 agomir to MSC-Exo to form Agomir21-Exo, which significantly reversed the apoptosis of granulosa cells in vitro. Moreover, we successfully developed GelMA hydrogel microspheres for encapsulating Agomir21-Exo through microfluidic technology, named GelMA-Ag21Exo, which had good injectability and significantly enhanced the stability and long-term retention of Agomir21-Exo in mice through sustained release. The release of Agomir21-Exo from GelMA-Ag21Exo notably alleviated the apoptosis of ovarian granulosa cells and improved the ovarian reserve and fertility in POI mice.ConclusionOur findings illustrate that activating miR-21 through Agomir21-Exo could improve the function of ovarian granulosa cells. The GelMA-Ag21Exo enhanced the exosome-based therapeutic efficacy of the Agomir21-Exo in vivo. These findings provide a novel and promising treatment strategy for POI patients.
Project description:Follicle-stimulating hormone receptor (FSHR) and its intracellular signaling control mammalian follicular development and female infertility. Our previous study showed that FSHR is downregulated during follicular atresia of porcine ovaries. However, its role and regulation in follicular atresia remain unclear. Here, we showed that FSHR knockdown induced porcine granulosa cell (pGC) apoptosis and follicular atresia, and attenuated the levels of intracellular signaling molecules such as PKA, AKT and p-AKT. FSHR was identified as a target of miR-143, a microRNA that was upregulated during porcine follicular atresia. miR-143 enhanced pGC apoptosis by targeting FSHR, and reduced the levels of intracellular signaling molecules. SMAD4, the final molecule in transforming growth factor (TGF)-β signaling, bound to the promoter and induced significant downregulation of miR-143 in vitro and in vivo. Activated TGF-β signaling rescued miR-143-reduced FSHR and intracellular signaling molecules, and miR-143-induced pGC apoptosis. Overall, our findings offer evidence to explain how TGF-β signaling influences and FSHR signaling for regulation of pGC apoptosis and follicular atresia by a specific microRNA, miR-143.
Project description:BackgroundBiosynthesis of 17β-estradiol (E2) is a crucial ovarian function in mammals, which is essential for follicular development and pregnancy outcome. Exploring the epigenetic regulation of E2 synthesis is beneficial for maintaining ovary health and the optimal reproductive traits. NORFA is the first validated sow fertility-associated long non-coding RNA (lncRNA). However, its role on steroidogenesis is elusive. The aim of this study is to investigate the regulation and underlying mechanism of NORFA to E2 synthesis in sow granulosa cells (GCs).ResultsThrough Pearson correlation analysis and comparative detection, we found that NORFA expression was positively correlated with the levels of pregnenolone (PREG) and E2 in follicles, which also exhibited similar alteration patterns during follicular atresia. ELISA was conducted and indicated for the first time that NORFA induced the synthesis of PREG and E2 in sow GCs in a dose- and time-dependent manner. RNA-seq, GSEA and quantitative analyses results validated that CYP11A1, the coding gene of P450SCC which is the first step rate-limiting enzyme of E2 synthesis, was a positive functional target of NORFA. Mechanistically, NORFA promotes SF-1 expression by stabilizing NR5A1 mRNA through directly interacting with its 3'-UTR, and also tethers SF-1 to shuttle into nucleus. Additionally, SF-1 in the nucleus activates CYP11A1 transcription by directly binding to its promoter, which ultimately induces E2 synthesis and inhibits GC apoptosis.ConclusionOur findings highlight that NORFA, a multifunctional lncRNA, induces E2 synthesis and inhibits GC apoptosis through the SF-1/CYP11A1 axis in a ceRNA-independent manner, which provide valuable clues and potential targets for follicular atresia inhibition and female fertility improvement.
Project description:The hyaluronan synthase 2 (HAS2)-hyaluronic acid (HA)-CD44-Caspase-3 pathway is involved in ovarian granulosa cell (GC) functions in mammals. HAS2 is a key enzyme required for HA synthesis and is the key factor in this pathway. However, the regulation of HAS2 and the HAS2-mediated pathway by microRNAs in GCs is poorly understood. Here, we report that miR-26b regulates porcine GC (pGC) apoptosis through the HAS2-HA-CD44-Caspase-3 pathway by binding directly to the 3'- untranslated region of HAS2 mRNA. Knockdown of miR-26b reduced pGC apoptosis. Luciferase reporter assays demonstrated that HAS2 is a direct target of miR-26b in pGCs. Knockdown and overexpression of miR-26b increased and decreased, respectively, HA content, and HAS2 and CD44 expression in pGCs. At the same time, inhibition and overexpression of miR-26b decreased and increased the expression of Caspase-3, a downstream factor in the HAS2-HA-CD44 pathway. Moreover, knockdown of HAS2 enhanced pGC apoptosis, reduced the inhibitory effects of a miR-26b inhibitor on pGC apoptosis, repressed HA content and CD44 expression, and promoted Caspase-3 expression. In addition, overexpression of HAS2 has a opposite effect. Collectively, miR-26b positively regulates pGC apoptosis via a novel HAS2-HA-CD44-Caspase-3 pathway by targeting the HAS2 gene.
Project description:Poor ovarian responders (PORs) pose a great challenge for in vitro fertilization (IVF). Previous studies have suggested that dehydroepiandrosterone (DHEA) may improve IVF outcomes in PORs. The current study attempted to investigate the clinical benefits of DHEA in PORs and the possible mechanisms of DHEA on cumulus cells (CCs). This was a prospective study performed at one tertiary center from January 2015 to March 2016. A total of 131 women who underwent IVF treatment participated, including 59 normal ovarian responders (NORs) and 72 PORs. PORs were assigned to receive DHEA supplementation or not before the IVF cycle. For all patients, CCs were obtained after oocyte retrieval. In the CCs, mRNA expression of apoptosis-related genes and mitochondrial transcription factor A (TFAM) gene, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, mitochondrial dehydrogenase activity and mitochondrial mass were measured. The results indicated that PORs with DHEA supplementation produces a great number of top-quality embryos at day 3 and increased the number of transferred embryos and fertilization rate compared with those without DHEA supplementation. Additionally, supplementation with DHEA in PORs decreased DNA damage and apoptosis in CCs while enhancing the mitochondrial mass, mitochondrial dehydrogenase activity and TFAM expression in CCs. In conclusion, our results showed that the benefits of DHEA supplementation on IVF outcomes in PORs were significant, and the effects may be partially mediated by improving mitochondrial function and reducing apoptosis in CCs.
Project description:Controlled ovarian stimulation with subsequent multi-follicular development continues to be a keystone in ART. Evidence supports an individualized approach to ovarian stimulation, usually involving combinations of ovarian reserve tests, body mass index and age to tailor the exogenous gonadotropin dose, and potentially adjuvant treatment aiming for high safety and a shortening of time to live birth. While stimulation and trigger concepts have been developed successfully in normo- and hyperresponder patients, the poor responder patient remains difficult to manage. However, recent advances in definition and classification of the expected poor ovarian responder patient might enable a more accurate and clinically useful interpretation of new treatment concepts in a more homogenous study population. In the present review, we discuss the classification of the expected poor ovarian responder patient as well as clinically useful measurements of efficacy for controlled ovarian stimulation, and finally, we discuss the evidence for clinical management of patients with expected poor ovarian response, including adjuvant treatments such as growth hormone, androgens, and LH activity.In conclusion, the best available evidence supports that the treatment of the expected poor ovarian response patient should be individualized in all steps of ART, including the choice of GnRH analogue, the gonadotropin type and dose, ovulation trigger, and the possible use of adjuvant therapies.