Hongbin Liu

STMN1 Promotes Progesterone Production Via StAR Up-regulation in Mouse Granulosa Cells

Stathmin 1 (STMN1) is a biomarker in several types of neoplasms. It plays an important role in cell cycle progression, mitosis, signal transduction and cell migration. In ovaries, STMN1 is predominantly expressed in granulosa cells (GCs). However, little is known about the role of STMN1 in ovary. In this study, we demonstrated that STMN1 is overexpressed in GCs in patients with polycystic ovary syndrome (PCOS). In mouse primary GCs, the overexpression of STMN1 stimulated progesterone production, whereas knockdown of STMN1 decreased progesterone production. We also found that STMN1 positively regulates the expression of Star (steroidogenic acute regulatory protein) and Cyp11a1 (cytochrome P450 family 11 subfamily A member 1). Promoter and ChIP assays indicated that STMN1 increased the transcriptional activity of Star and Cyp11a1 by binding to their promoter regions. The data suggest that STMN1 mediates the progesterone production by modulating the promoter activity of Star and Cyp11a1. Together, our findings provide novel insights into the molecular mechanisms of STMN1 in ovary GC steroidogenesis. A better understanding of this potential interaction between STMN1 and Star in progesterone biosynthesis in GCs will facilitate the discovery of new therapeutic targets in PCOS.

Association of AQP8 in women with PCOS

Aquaporin 8 (AQP8) has been identified as a novel gene participating in female reproductive physiology. The present study was designed to determine whether an association exists between AQP8 and polycystic ovary syndrome (PCOS). This study recruited 192 women with PCOS and 191 controls. High-resolution melting and sequencing were employed to investigate the genotypes of six single-nucleotide polymorphisms within AQP8 (rs7198838, rs1076973, rs1076974, rs2287797, rs2287798 and rs2287796). A significant difference was found in rs2287798 between PCOS cases and controls (P=0.0007). Possible associations between AQP8 genotypes and three different phenotypes of this syndrome were investigated. The results support the earlier evidence for a possible role of AQP8 in the pathogenesis of PCOS. Further studies are still needed to elucidate its functional role. Aquaporin 8 (AQP8) has been identified as a novel gene participating in female reproductive physiology. The present study was designed to determine whether there is an association between AQP8 and polycystic ovary syndrome (PCOS). This study recruited 192 women with PCOS and 191 controls. High-resolution melting and sequencing were employed to investigate the genotypes of six single-nucleotide polymorphisms within AQP8 (rs7198838, rs1076973, rs1076974, rs2287797, rs2287798 and rs2287796). We observed a significant difference in allele frequency of rs2287798 between PCOS cases and controls (P=0.0007). The possible association between AQP8 genotypes and three different phenotypes of this syndrome in this locus were investigated. Our results support the earlier evidence for a possible role of AQP8 in the pathogenesis of PCOS. Further studies are still needed to elucidate its functional role.

Family-based analysis of eight susceptibility loci in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that is proposed to have a genetic basis. A recent genome-wide association study (GWAS) identified eight new risk loci that are independently associated with PCOS. To further validate the findings, a total of 321 case-parent trios (963 participants) who had a proband affected with PCOS were recruited for the family-based study. The transmission disequilibrium test (TDT) was used to analyze associations between PCOS and ten single nucleotide polymorphisms (SNPs) mapped to eight new susceptibility loci. Significant differences in transmission were observed for the SNPs rs2349415 (located in the FSHR gene, Pu2009=u20090.0001) and rs3802457 (located in the C9orf3 gene, Pu2009=u20090.0001), even after correction for multiple testing bias. The present data provides further evidence for an association between two susceptibility loci, 2p16.3 and 9q22.32, and PCOS. Follow-up functional studies on the FSHR and C9orf3 genes are required to understand their roles in PCOS development.

The HMGA2-IMP2 Pathway Promotes Granulosa Cell Proliferation in Polycystic Ovary Syndrome.

CONTEXTnThe high mobility group AT hook 2 (HMGA2) gene was previously identified in a genome-wide association study as a candidate risk gene that might be related to polycystic ovary syndrome (PCOS). Whether HMGA2 contributes to promoting granulosa cell (GC) proliferation in PCOS remains unknown.nnnOBJECTIVEnWe sought to determine whether HMGA2 is involved in the ovarian dysfunction of PCOS and in the mechanism of increased GC proliferation.nnnPATIENTS AND CELLSnmRNA expression was analyzed in ovarian GCs from 96 women with PCOS and 58 healthy controls. Immortalized human GCs (KGN and SVOG cells) were used for the mechanism study.nnnMAIN OUTCOME MEASURESnmRNA expression in ovarian GCs was measured using quantitative RT-PCR, and KGN cells were cultured for proliferation assays after overexpression or knockdown of target genes. Protein expression analysis, luciferase assays, and RNA binding protein immunoprecipitation assays were used to confirm the mechanism study.nnnRESULTSnHMGA2 and IGF2 mRNA binding protein 2 (IMP2) were highly expressed in the GCs of women with PCOS, and the HMGA2/IMP2 pathway promoted GC proliferation. Cyclin D2 and SERPINE1 mRNA binding protein 1 were regulated by IMP2 and were highly expressed in women with PCOS.nnnCONCLUSIONSnThe HMGA2/IMP2 pathway was activated in women with PCOS and promoted the proliferation of GCs. This might provide new insights into the dysfunction of GCs in PCOS.

Mutational analysis of IZUMO1R in women with fertilization failure and polyspermy after in vitro fertilization

PurposeThe etiology of fertilization failure and polyspermy during assisted reproductive technology (ART) remains elusive. The aim of this study was to determine whether mutations in the IZUMO1 receptor (IZUMO1R) gene, which is essential for mammalian fertilization, contribute to the pathogenesis of fertilization failure or polyspermy in humans.MethodsWe recruited 215 female subjects with fertilization failure/poor fertilization, 330 females with polyspermy, and 300 matched controls. All subjects underwent IVF treatment. Peripheral blood DNA of cases was extracted and screened for mutations in IZUMO1R gene.ResultsFour rare single nucleotide polymorphisms (SNPs) of the IZUMO1R were identified among specimens from patients with fertilization failure and polyspermy but were absent in the 300 control subjects. These included a missense SNP (rs76779571 in exon 4), which was found in two fertilization failure patients, and a nonsynonymous SNP (rs61742524 in exon 1) and two synonymous SNPs (rs76781645 in exon 1 and rs377369966 in intron 2), which were found among three polyspermy cases.ConclusionsThe variations in IZUMO1R might play a role in the pathogenesis of fertilization failure and polyspermy, and the putative functions and effects of these rare variants require further studies.

Wilms’ Tumor 1 Overexpression in Granulosa Cells Is Associated with Polycystic Ovaries in Polycystic Ovary Syndrome Patients

Background: Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by chronic ovulatory dysfunction, hyperandrogenism, and polycystic ovaries. Wilms’ tumor 1 (WT1) encoding a transcription factor involved in the differentiation of granulosa cells (GCs) regulates androgen receptor in the development of male genitalia. However, the expression pattern and possible role of WT1 in ovaries of PCOS patients are still unknown. Methods: GCs from 95 PCOS patients (PCOS group) and 62 healthy controls (control group) were isolated. The expression of WT1 in GCs was quantified using the reverse transcription-polymerase chain reaction. The correlation between WT1 expression and clinical characteristics was evaluated in PCOS patients. Results: WT1 expression was increased in PCOS patients compared with the normal controls. The expression of WT1 was moderately correlated with testosterone (r = 0.334, p = 0.001) and luteinizing hormone (r = 0.357, p = 0.001) levels and the antral follicle counts (r = 0.337, p = 0.001). Conclusions: Our study provided novel insights into the relationship between hyperandrogenism and polycystic ovaries of PCOS and WT1.

Corrigendum to “Long non-coding RNA LINC-01572:28 inhibits granulosa cell growth via a decrease in p27 (Kip1) degradation in patients with polycystic ovary syndrome” [EBioMedicine 36 (2018) 526–538]

a Center for Reproductive Medicine, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135, China b Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Shanghai 200135, China c Center for Reproductive Medicine, Shandong Provincial Hospital, Shandong University, National Research Center for Assisted Reproductive Technology and Reproductive Genetics, The Key Laboratory for Reproductive Endocrinology (Shandong University), Ministry of Education, Shandong Provincial Clinical Medicine Research Center for reproductive health, Shandong Provincial Key Laboratory of Reproductive Medicine, No.157 Jingliu Road, Jinan 250001, China d Icahn School of Medicine at Mount Sinai, Atran Bldg, 1428 Madison Ave., 4th floor, Rm 4-36, One Gustave L. Levy Place, Box 1055, New York, NY 10029, USA

Long non-coding RNA LINC-01572:28 inhibits granulosa cell growth via a decrease in p27 (Kip1) degradation in patients with polycystic ovary syndrome

Background Disordered folliculogenesis is a key feature of polycystic ovary syndrome (PCOS), but the underlying molecular mechanism remains unclear. Methods Long non-coding RNA (lncRNA) expression in luteinized granulosa cells (hLGCs) derived from women with and without PCOS were analyzed using microarray and qRT-PCR. Immortalized human granulosa cell lines were cultured for proliferation assays after transfection with the LINC-01572:28 over-expression vector in the presence or absence of p27 siRNA. Protein expression analysis, rescue assays, and RNA immunoprecipitation (RIP) were used to confirm the LINC-01572:28 substrate. Findings LINC-01572:28 and p27 protein were elevated whereas proliferating cell nuclear antigen protein was decreased in the hLGCs of women with PCOS. LINC-01572:28 expression was positively correlated with basal testosterone levels. Over-expression of LINC-01572:28 inhibited cell proliferation and impeded G1/S transition, which were partially reversed by siRNA-mediated p27 knockdown. Interpretation Our findings, therefore, suggest that LINC-01572:28 suppresses cell proliferation and cell cycle progression by reducing the degradation of p27 protein via SKP2 binding.

Integrated microRNA and mRNA signatures in peripheral blood lymphocytes of familial epithelial ovarian cancer

PURPOSEnCharacterization of the genetic landscapes of familial ovarian cancer through integrated analysis of microRNA and mRNA by partial least squares (PLS) and Monte Carlo technique based on genome-wide association studies (GWAS).nnnMETHODSnThe miRNA and mRNA transcriptional data in familial ovarian cancer were characterized from the Gene Expression Omnibus (GEO) database. The miRNA and mRNA expression profiles in peripheral blood lymphocytes (PBLs) of 74 familial ovarian cancer patients and 47 control subjects were analyzed with the integration of partial least squares (PLS) and Monte Carlo techniques. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were also performed.nnnRESULTSnTotal of 16 miRNA-mRNA pairs were identified with the target gene prediction results of miRNAs and mRNAs. An innovated miRNA-mRNA integrated network was constructed in which 6 downregulated miRNAs and 1 upregulated miRNAs were included. KEGG and GO pathway enrichment analysis revealed over-representation of dysregulated miRNAs in various biological processes especially in cancer pathology. Hsa-miR-34b played a pivotal role in this network and interacted with other miRNAs. Hsa-miR-136 and hsa-miR-335 were associated with p53 and Erk1/2 pathways and tumor suppressors, such as PTEN.nnnCONCLUSIONSnThe results from this research provide insights on miRNA-mRNA networks and offer new tools for studying transcriptional variants in familial ovarian cancer.

Identification of reference genes for qRT-PCR in granulosa cells of healthy women and polycystic ovarian syndrome patients

Comparative gene expression analysis by qRT-PCR is commonly used to detect differentially expressed genes in studies of PCOS pathology. Impaired GC function is strongly associated with PCOS pathogenesis, and a growing body of studies has been dedicated to identifying differentially expressed genes in GCs in PCOS patients and healthy women by qRT-PCR. It is necessary to validate the expression stability of the selected reference genes across the tested samples for target gene expression normalization. We examined the variability and stability of expression of the 15 commonly used reference genes in GCs from 44 PCOS patients and 45 healthy women using the GeNorm, BestKeeper, and NormFinder statistical algorithms. We combined the rankings of the three programs to produce a final ranking based on the geometric means of their stability scores. We found that HPRT1, RPLP0, and HMBS out of 15 examined commonly used reference genes are stably expressed in GCs in both controls and PCOS patients and can be used for normalization in gene expression profiling by qRT-PCR. Future gene-expression studies should consider using these reference genes in GCs in PCOS patients for more accurate quantitation of target gene expression and data interpretation.