Highlights d RNA-seq of oocytes and granulosa cells mapped transcriptome and signature genes d KEGG/GSEA analysis uncovered pathways involved in primordial follicle activation d Oocyte-granulosa cell interactions exhibit stage-and species-specific patterns d RNA-seq analysis identified candidate secretory biomarkers of ovarian reserve

BACKGROUNDInitially identified for their capability to induce heterotopic bone formation, bone morphogenetic proteins (BMPs) are multifunctional growth factors that belong to the transforming growth factor β superfamily. Using cellular and molecular genetic approaches, recent studies have implicated intra-ovarian BMPs as potent regulators of ovarian follicular function. The bi-directional communication of oocytes and the surrounding somatic cells is mandatory for normal follicle development and oocyte maturation. This review summarizes the current knowledge on the physiological role and molecular determinants of these ovarian regulatory factors within the human germline-somatic regulatory loop.OBJECTIVE AND RATIONALEThe regulation of ovarian function remains poorly characterized in humans because, while the fundamental process of follicular development and oocyte maturation is highly similar across species, most information on the regulation of ovarian function is obtained from studies using rodent models. Thus, this review focuses on the studies that used human biological materials to gain knowledge about human ovarian biology and disorders and to develop strategies for preventing, diagnosing and treating these abnormalities.SEARCH METHODSRelevant English-language publications describing the roles of BMPs or growth differentiation factors (GDFs) in human ovarian biology and phenotypes were comprehensively searched using PubMed and the Google Scholar database. The publications included those published since the initial identification of BMPs in the mammalian ovary in 1999 through July 2016.OUTCOMESStudies using human biological materials have revealed the expression of BMPs, GDFs and their putative receptors as well as their molecular signaling in the fundamental cells (oocyte, cumulus/granulosa cells (GCs) and theca/stroma cells) of the ovarian follicles throughout follicle development. With the availability of recombinant human BMPs/GDFs and the development of immortalized human cell lines, functional studies have demonstrated the physiological role of intra-ovarian BMPs/GDFs in all aspects of ovarian functions, from follicle development to steroidogenesis, cell–cell communication, oocyte maturation, ovulation and luteal function. Furthermore, there is crosstalk between these potent ovarian regulators and the endocrine signaling system. Dysregulation or naturally occurring mutations within the BMP system may lead to several female reproductive diseases. The latest development of recombinant BMPs, synthetic BMP inhibitors, gene therapy and tools for BMP-ligand sequestration has made the BMP pathway a potential therapeutic target in certain human fertility disorders; however, further clinical trials are needed. Recent studies have indicated that GDF8 is an intra-ovarian factor that may play a novel role in regulating ovarian functions in the human ovary.WIDER IMPLICATIONSIntra-ovarian BMPs/GDFs are critical regulators of folliculogenesis and human ovarian functions. Any dysregulation or variations in these ligand...

BACKGROUND Despite great advances in assisted reproductive technology, poor ovarian response (POR) is still considered as one of the most challenging tasks in reproductive medicine. OBJECTIVE AND RATIONALE The aim of this systemic review is to evaluate the role of different adjuvant treatment strategies on the probability of pregnancy achievement in poor responders undergoing IVF. Randomized controlled trials (RCTs) comparing 10 adjuvant treatments [testosterone, dehydroepiandrosterone (DHEA), letrozole, recombinant LH, recombinant hCG, oestradiol, clomiphene citrate, progesterone, growth hormone (GH) and coenzyme Q10 (CoQ10)] were included. SEARCH METHODS Relevant studies published in the English language were comprehensively selected using PubMed, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) until 11 July 2018. We included studies that investigated various adjuvant agents, including androgen and androgen-modulating agents, oestrogen, progesterone, clomiphene citrate, GH and CoQ10, during IVF treatment and reported subsequent pregnancy outcomes. The administration of GnRH analogs and gonadotrophins without adjuvant treatment was set as the control. We measured study quality based on the methodology and categories listed in the Cochrane Collaboration Handbook. This review protocol was registered with PROSPERO (CRD42018086217). OUTCOMES Of the 1124 studies initially identified, 46 trials reporting on 6312 women were included in this systematic review, while 19 trials defining POR using the Bologna criteria reporting 2677 women were included in the network meta-analysis. Compared with controls, DHEA and CoQ10 treatments resulted in a significantly higher chance of clinical pregnancy [odds ratio (OR) 2.46, 95% CI 1.16 to 5.23; 2.22, 1.08–4.58, respectively]. With regard to the number of retrieved oocytes, HCG, oestradiol and GH treatments had the highest number of oocytes retrieved [weighted mean difference (WMD) 2.08, 0.72 to 3.44; 2.02, 0.23 to 3.81; 1.72, 0.98 to 2.46, compared with controls, respectively]. With regard to the number of embryos transferred, testosterone and GH treatment led to the highest number of embryos transferred (WMD 0.72, 0.11 to 1.33; 0.67, 0.43 to 0.92; compared with controls, respectively). Moreover, GH resulted in the highest oestradiol level on the HCG day (WMD 797.63, 466.45 to 1128.81, compared with controls). Clomiphene citrate, letrozole and GH groups used the lowest dosages of gonadotrophins for ovarian stimulation (WMD 1760.00, −2890.55 to −629.45; −1110.17, −1753.37 to −466.96; −875.91, −1433.29 to −282.52; compared with controls, respectively). CoQ10 led to the lowest global cancelation rate (OR 0.33, 0.15 to 0.74, compared with controls). WIDER IMPLICATIONS For patients with POR, controlled ovarian stimulation protocols using adjuvant treatment with DHEA, CoQ10 and GH showed better clinical outcomes in terms of achieving pregnancy, and a lower dosage of gonadotrophin required for ovulation induction. Furthermore, high-level RCT studies using uniform standards for POR need to be incorporated into future meta-analyses.