Gn-RH as an Autocrine Regulator in the Human Ovary

Leung, Peter C.K.; Cheng, Chi Keung

doi:10.1016/b978-012444562-8/50018-5

Cited by 5 publications

(3 citation statements)

References 108 publications

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“…Changes in the immunolocalization of these peptides during diestrus 2 coincide with the beginning of luteolytic activity in the corpus luteum and a decline in progesterone concentration. It has earlier been suggested that GnRH may function as a permissive factor for the process of luteolysis (Leung and Cheng 2004). GnRH I-receptor mRNA is also demonstrated in human luteinized granulosa cells (Peng et al 1994) and in human ovarian homogenate across different functional stages of the menstrual cycle (Minaretzis et al 1995).…”

Section: Discussionmentioning

confidence: 99%

Immunohistochemical localization of GnRH and RFamide-related peptide-3 in the ovaries of mice during the estrous cycle

et al. 2011

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Gonadotropin releasing hormone (GnRH) has now been suggested as an important intraovarian regulatory factor. Gonadotropin inhibitory hormone (GnIH) a hypothalamic dodecapeptide, acts opposite to GnRH. GnRH, GnIH and their receptors have been demonstrated in the gonads. In order to find out the physiological significance of these neuropeptides in the ovary, we aim to investigate changes in the abundance of GnRH I and GnIH in the ovary of mice during estrous cycle. The present study investigated the changes in GnRH I, GnRH I-receptor and RFRP-3 protein expression in the ovary of mice during estrous cycle by immunohistochemistry and immunoblot analysis. The immunoreactivity of GnRH I and its receptor and RFRP-3 were mainly localized in the granulosa cells of the healthy and antral follicles during proestrus and estrus and in the luteal cells during diestrus 1 and 2 phases. The relative abundance of immunoreactivity of GnRH I, GnRH I-receptor and RFRP-3 undergo significant variation during proestrus and thus may be responsible for selection of follicle for growth and atresia. A significant increase in the concentration of RFRP-3 during late diestrus 2 coincided with the decline in corpus luteum activity and initiation of follicular growth and selection. In general, immunolocalization of GnRH I, GnRH I-receptor and RFRP-3 were found in close vicinity suggesting functional interaction between these peptides. It is thus, hypothesized that interaction between GnRH I-RFRP-3 neuropeptides may be involved in the regulation of follicular development and atresia.

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Section: Discussionmentioning

confidence: 99%

Immunohistochemical localization of GnRH and RFamide-related peptide-3 in the ovaries of mice during the estrous cycle

et al. 2011

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“…GnRH is now regarded as an important paracrine and autocrine factor in the ovary [ 16 ]. However, the mechanism through which GnRH analogs affect gonadal functions in intact cyclic animal is still obscure.…”

Section: Introductionmentioning

confidence: 99%

Effects of GnRH agonist treatment on steroidogenesis and folliculogenesis in the ovary of cyclic mice

Singh

Krishna

2010

Journal of Ovarian Research

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BackgroundGnRH analogs (both agonist and antagonist) have been extensively used for clinical applications, following the discovery of its direct effects on ovary. With regard to the direct actions of GnRH agonist on ovary, conflicting data are reported. The mechanism through which GnRH agonist affect gonadal functions is still obscure. The aim of present study was thus to investigate the effects of treatment with different doses of GnRH agonist, in vivo and in vitro, on morphological, physiological and functional changes in the ovary of cyclic mice.MethodsTo find out the effect of GnRH agonist on ovarian activity, cyclic mice were treated with different doses for 8 days and its effect on folliculogenesis (morphological changes in follicle, Estrogen receptor, progesterone receptor), steroidogenesis (circulating progesterone level, StAR, LH-receptor, 3β-HSD), luteinization (Morphology of corpus luteum) and apoptosis (caspase-3, PARP) were observed. To find the in vitro effects of GnRH agonist with or without LH on ovary of mice, changes in the expression of LH-receptor, estrogen receptor, progesterone receptor, 3β-HSD in the ovary and progesterone level in the culture media were investigated.ResultsGnRH agonist treatment produced significant changes in ovarian mass, circulating steroids level and ovarian follicular development, steroidogenesis and apoptosis in the mice. GnRH agonist also caused dose dependent histological changes in follicular development and luteinization. The mice treated with different doses of GnRH agonist showed biphasic effects on steroid synthesis due to its effects on ovarian expression of LH-receptor, StAR, and 3β -hydroxysteroid dehydrogenase proteins. The high dose showed stimulatory effect, whereas pharmacological dose showed inhibitory effect on ovarian follicular development and steroidogenesis. The in vitro study generally showed inhibitory effects of GnRH agonist on ovarian activities, which may be reversed by the presence of LH.ConclusionBoth inhibitory and stimulatory effects found in the present study suggest that GnRH agonist is a versatile tool in the therapy of a variety of gynecological and non-gynecological conditions. This study suggests that the outcome of direct effect of GnRH-ag on ovary depends on LH-responsiveness.

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“…The studies described so far suggest that both GnRH and GnIH act as important autocrine/paracrine factors that modulate follicle development, apoptosis, luteinization and steroidogenesis in the ovaries of mammals. GnRH and GnIH have also been proposed as a possible treatment for variety of reproductive dysfunctions [10,27]. Our recent study suggests that GnRH may restore ovulation in polycystic ovarian (PCO-mice) and thus may be utilized as a therapeutic agent to treat polycystic ovarian syndrome [10].…”

Section: Validation Of Proteomic Studymentioning

confidence: 99%

Comparative proteomic analysis of the mouse ovary in response to GnIH and GnRH: An in vitro approach

Dave¹,

Powell²,

Sridaran³

et al. 2019

Integr Mol Med

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The present study conducted proteomic analysis to identify ovarian proteins induced by GnRH/GnIH in comparison with untreated control mice. We used methods of 2-dimentional gel electrophoresis and LC-MS/MS for protein identification. Out of the 25 differentially expressed spots from each of the GnRH/GnIH treated ovaries we were randomly selected 18 protein spots identified by LC-MS/MS. The proteins 14-3-3, prohibitin and superoxide dismutase (SOD1) identified by LC-MS/MS were further verified by Western blotting, which confirmed that GnRH/GnIH-induced changes in expression of 14-3-3, prohibitin and SOD1 were similar to the observations of proteomics. These selected proteins, 14-3-3, prohibitin and SOD1, were further have been the correlation with various ovarian activities, such as cell proliferation, survival or markers of apoptotic. Out of 18 identified GnRH-induced proteins, 9 showed up-regulations whereas other 9 showed down-regulations. This finding suggests that GnRH acts both by stimulating and inhibiting expression of protein. Interestingly, in the GnIH-induced ovary, 15 out of 18 proteins were significantly down-regulated suggesting that, GnIH acts mainly by inhibiting the expression of proteins involved in ongoing ovarian activities. Thus, the present study indicates many of the identified GnRH/GnIH-induced proteins are potentially linked to ovarian follicular development, atresia, steroidogenesis and cancer.

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Gn-RH as an Autocrine Regulator in the Human Ovary

Cited by 5 publications

References 108 publications

Immunohistochemical localization of GnRH and RFamide-related peptide-3 in the ovaries of mice during the estrous cycle

Immunohistochemical localization of GnRH and RFamide-related peptide-3 in the ovaries of mice during the estrous cycle

Effects of GnRH agonist treatment on steroidogenesis and folliculogenesis in the ovary of cyclic mice

Comparative proteomic analysis of the mouse ovary in response to GnIH and GnRH: An in vitro approach

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