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Elucidating Decorin's role in the preovulatory follicle. Kedem A et al. (2020) DCN (decorin) is a proteoglycan known to be involved in regulating cell proliferation, collagen fibril organization and migration. In our global transcriptome RNA-sequencing approach to systematically identify new ovulation-associated genes, DCN was identified as one of the highly regulated genes. We therefore hypothesize that DCN may have a role in ovulatory processes such as cell migration and proliferation. To characterize the expression, regulation and function of the proteoglycan DCN in the human ovarian follicles during the preovulatory period. The in-vivo expression of DCN mRNA in mural (MGCs) and cumulus (CGCs) granulosa cells was characterized using quantitative RT-PCR and western blot. A signaling study was performed by treating human MGCs cultures with gonadotropins and different stimulators and inhibitors to determine their effect on DCN expression by qRT- PCR and elucidate the pathways regulating these proteins. In a functional study, KGN granulosa cell line was used to study cell migration with a scratch assay. DCN mRNA expression was significantly higher in MGCs compared to CGCs. DCN mRNA was significantly higher in CGCs surrounding mature metaphase II (MII) oocytes compared to CGCs of germinal vesicle (GV) and metaphase I (MI) oocytes. hCG significantly increased DCN mRNA and protein expression levels in cultured MGCs. Using signal transduction activators and inhibitors, we demonstrated that DCN induction by LH/hCG is carried out via PKA, PKC, ERK/MEK, and PI3K pathways. We showed that DCN expression is also induced in high-density cell cultures, in a dose-dependent pattern. In addition, progesterone induced a significant increase in DCN secretion to the media. MGCs from follicles of endometriosis patients exhibited reduced (about 20% of) mRNA transcriptions levels compared to MGCs follicles of control patients. More significantly, we found that DCN has an inhibiting effect on KGN cell migration. Our study indicates that DCN is a unique ovulatory gene. Our findings support the hypothesis that DCN plays an important new role during the preovulatory period and ovulation, and stress its involvement in endometriosis infertility. A better understanding of DCN role in ovulation and endometriosis may provide treatment for some types of infertility.////////////////// Clinical utility of decorin in follicular fluid as a biomarker of oocyte potential. Sawada Y et al. (2017) This study investigated the concentration of decorin (DCN) in mature follicular fluid and the existence in the granulosa cells. It also investigated whether DCN is useful as a biomarker for outcomes of assisted reproductive technology (ART). A retrospective cohort study was performed involving 130 oocytes of 88 patients treated with ART because of unexplained infertility. The concentration of DCN in the follicular fluid (F-DCN) was 39.26ng/ml (median value); it was higher than that in serum. F-DCN of the oocytes fertilized by intracytoplasmic sperm injection (ICSI) was significantly lower than that of oocytes that were not fertilized (33.24ng/ml vs 40.18ng/ml; P=0.043). When a cut-off level of 34.5ng/ml was set according to the receiver-operating characteristic curve, the fertilization rate of the oocytes from the follicles in which F-DCN was lower than the cut-off level tended to be good compared to that of the oocytes with F-DCN higher than the cut-off level (P=0.052). DCN is less likely to be produced by the granulosa cells (GCs), because it was not detected in GCs by immunostaining and Western blot analysis. F-DCN has a possibility to be a biomarker indicating the quality of oocytes collected from the corresponding follicle.//////////////////
Decorin is a part of the ovarian extracellular matrix in primates and may act as a signaling molecule. Adam M et al. STUDY QUESTIONIs decorin (DCN), a putative modulator of growth factor (GF) signaling, expressed in the primate ovary and does it play a role in ovarian biology?SUMMARY ANSWERDCN expression in the theca, the corpus luteum (CL), its presence in the follicular fluid (FF) and its actions revealed in human IVF-derived granulosa cells (GCs), suggest that it plays multiple roles in the ovary including folliculogenesis, ovulation and survival of the CL.WHAT IS KNOWN ALREADYDCN is a secreted proteoglycan, which has a structural role in the extracellular matrix (ECM) and also interferes with the signaling of multiple GF/GF receptors (GFRs). However, DCN expression and action in the primate ovary has yet to be determined.STUDY DESIGN, SIZE, DURATIONArchival human and monkey ovarian samples were analyzed. Studies were conducted using FF and GC samples collected from IVF patients.PARTICIPANTS/MATERIALS, SETTING, METHODSImmunohistochemistry, western blotting, RT-PCR, quantitative RT-PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA) studies were complemented by cellular studies, including the measurements of intracellular Ca(2+), reactive oxygen species (ROS), epidermal GF receptor (EGFR) phosphorylation by DCN and caspase activity.MAIN RESULTS AND THE ROLE OF CHANCEImmunohistochemistry revealed strong DCN staining in the connective tissue and follicular thecal compartments, but not in GCs of pre-antral and antral follicles. Pre-ovulatory follicles could not be studied, but DCN was associated with connective tissue of CL samples and the cytoplasm of luteal cells. DCN expression in monkey CL doubled (P < 0.05) towards the end of the luteal lifespan. DCN was found in human FF obtained from IVF patients (mean: 12.9 ng/ml; n = 20) as determined by ELISA. DCN mRNA and/or protein were detected in freshly isolated and cultured, luteinized human GCs. In the latter, exogenous human recombinant DCN increased intracellular Ca(2+) levels and induced the production of ROS in a concentration-dependent manner. DCN, like epidermal GF, phosphorylated EGFR significantly (P < 0.05) and reduced the activity of caspase 3/7 in cultured GCs. The data indicate the expression of DCN in the theca of growing follicles, in FF of ovulatory follicles and in the CL. Therefore, DCN may exert paracrine actions via GF/GFR systems in multiple ovarian compartments.LIMITATIONS, REASONS FOR CAUTIONFunctional studies were performed in cultures of human luteinized GCs, which are an apt model but may not fully mirror the pre-ovulatory GC compartment or the CL. Other human ovarian cells, including the thecal cells, were not available.WIDER IMPLICATIONS OF THE FINDINGSIn accordance with its evolving roles in other organs, ovarian DCN is an ECM-associated component, which acts as a multifunctional regulator of GF signaling in the primate ovary. DCN may thus be involved in folliculogenesis, ovulation and the regulation of the CL survival in primates.STUDY FUNDING/COMPETING INTEREST(S)This study was supported by Deutsche Forschungsgemeinschaft (DFG) MA1080/17-3 and in part DFG MA1080/21-1 (to AM), NIH grants HD24870 (S.R.O. and R.L.S.), the Eunice Kennedy Shriver NICHD/NIH through cooperative agreement HD18185 as part of the Specialized Cooperative Centers Program in Reproduction and Infertility Research (S.R.O.) and 8P51OD011092-53 for the operation of the Oregon National Primate Research Center (G.A.D., J.D.H., S.R.O. and R.L.S).
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Molecular cloning, expression analysis, and function of decorin in goat ovarian granulosa cells. Peng JY et al. (2016) Decorin (DCN), a component of the extracellular matrix (ECM), participates in ECM assembly and influences cell proliferation and apoptosis in many mammalian tissues and cells. However, expression and function of DCN in the ovary remain unclear. This study cloned the full-length cDNA of goat DCN obtained from the ovary of an adult goat. Sequence analysis revealed that the putative DCN protein shared a highly conserved amino acid sequence with known mammalian homologs. The tissue distribution of DCN mRNA expression was evaluated by real-time PCR, and the results showed that DCN was widely expressed in the tissues of adult goat. Immunohistochemistry results suggested that DCN protein existed in the granulosa cells and oocytes from all types of follicles and theca cells of antral follicles. Moreover, hCG-induced DCN mRNA expression was significantly reduced by the inhibitors of protein kinase A, PI3K, or p38 kinase (P < 0.05), which are key mediators involved in hCG-induced DCN expression. Overexpression of DCN significantly increased apoptosis and blocked cell cycle progression in cultured granulosa cells (P < 0.05). Western blot analysis also showed that overexpression of DCN upregulated the expression levels of p21 protein (P < 0.05), whereas no effects were observed on the expression of Bax and Bcl-2 and on Bcl-2/Bax ratio (P > 0.05). These findings suggested that DCN regulates the apoptosis and cell cycle of granulosa cells.//////////////////
Large chondroitin sulfate proteoglycans were first identified in hyaline cartilage, where they specifically interact with hyaluronan and
form large supramolecular complexes. Together with other matrix glycoproteins, they provide mechanical support and a fixed
negative charge. The core protein of fibroblast chondroitin
sulfate proteoglycan was designated versican in recognition of its versatile modular structure. Decorin (125255) and biglycan
(301870) are 2 other soft tissue proteoglycans.
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