scholarly journals The Adequate Corpus Luteum: miR-96 Promotes Luteal Cell Survival and Progesterone Production

2017 ◽  
Vol 102 (7) ◽  
pp. 2188-2198 ◽  
Author(s):  
Bushra T. Mohammed ◽  
Sadanand D. Sontakke ◽  
Jason Ioannidis ◽  
W. Colin Duncan ◽  
F. Xavier Donadeu

Abstract Context: Inadequate progesterone production from the corpus luteum is associated with pregnancy loss. Data available in model species suggest important roles of microRNAs (miRNAs) in luteal development and maintenance. Objective: To comprehensively investigate the involvement of miRNAs during the ovarian follicle-luteal transition. Design: The effects of specific miRNAs on survival and steroid production by human luteinized granulosa cells (hLGCs) were tested using specific miRNA inhibitors. Candidate miRNAs were identified through microarray analyses of follicular and luteal tissues in a bovine model. Setting: An academic institution in the United Kingdom associated with a teaching hospital. hLGCs were obtained by standard transvaginal follicular-fluid aspiration from 35 women undergoing assisted conception. Intervention(s): Inhibition of candidate miRNAs in vitro. Main outcome measure(s): Levels of miRNAs, mRNAs, FOXO1 protein, apoptosis, and steroids were measured in tissues and/or cultured cells. Results: Two specific miRNA clusters, miR-183-96-182 and miR-212-132, were dramatically increased in luteal relative to follicular tissues. miR-96 and miR-132 were the most upregulated miRNAs within each cluster. Database analyses identified FOXO1 as a putative target of both these miRNAs. In cultured hLGCs, inhibition of miR-96 increased apoptosis and FOXO1 protein levels, and decreased progesterone production. These effects were prevented by small interfering RNA-mediated downregulation of FOXO1. In bovine luteal cells, miR-96 inhibition also led to increases in apoptosis and FOXO1 protein levels. Conclusions: miR-96 targets FOXO1 to regulate luteal development through effects on cell survival and steroid production. The miR-183-96-182 cluster could provide a novel target for the manipulation of luteal function.

Reproduction ◽  
2015 ◽  
Vol 149 (1) ◽  
pp. 1-10 ◽  
Author(s):  
P Accialini ◽  
S F Hernández ◽  
D Bas ◽  
M C Pazos ◽  
G Irusta ◽  
...  

In this study, we investigated the interaction between the Notch pathway and progesterone to maintain the functionality of the corpus luteum (CL). When Notch signaling is activated, the γ-secretase complex releases the active intracellular domains (NICD) of their receptors, which exert survival effects. We designed studies to analyze whether thein vitroinhibition of Notch affects progesterone production, steroidogenic regulators, apoptotic parameters, and signaling transduction pathways in the cultures of CL isolated from pregnant and superovulated rats. We detected a decrease in progesterone production when corpora lutea (CL) were incubated withN-(N-(3,5-difluorophenacetyl-l-alanyl))-S-phenylglycine t-butyl ester (DAPT), a γ-secretase inhibitor. This effect could be in part due to the decrease detected in the CL protein levels of P450scc because STAR and 3β-hydroxysteroid dehydrogenase were not affected by Notch inhibition. Besides, the addition of aminoglutethimide to the CL culture medium decreased NICD of NOTCH1. We observed an increase in the expression of active CASPASE3 (CASP3) after inhibition by Notch, which was reversed by the presence of progesterone. The BAX:BCLXLratio was increased in CL treated with DAPT and the presence of progesterone reversed this effect. In addition, phosphorylation of AKT was inhibited in CL treated with DAPT, but had no effect on ERK activation. To demonstrate that the action of DAPT is specifically related with the inhibition of Notch, CLs were incubated with DLL4 antibody and a decrease in progesterone production was detected. These results suggest the existence of a novel link between progesterone and the Notch signaling pathway to maintain the functionality of the CL.


1977 ◽  
Vol 73 (1) ◽  
pp. 71-78 ◽  
Author(s):  
K. M. HENDERSON ◽  
K. P. McNATTY

SUMMARY The newly formed corpus luteum of many species is refractory to the lytic action of prostaglandin F2α (PGF2α). This phenomenon was studied utilizing porcine, bovine and human granulosa-luteal cells in tissue culture. The steroidogenic potential of the granulosa-luteal cells was critical in determining whether PGF2α could inhibit progesterone production. Since the steroidogenic potential of the granulosa-luteal cell is related to the amount of LH bound to the cell, the bound LH may protect the granulosa-luteal cells from the lytic action of PGF2α. Finally, a 'see-saw' type of interaction between LH and PGF2α is postulated to account for the resistance of the newly formed corpus luteum to PGF2α


2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Patricia Sanmartín-Salinas ◽  
Luis G. Guijarro

We reported that insulin receptor substrate 4 (IRS-4) levels increased in tissue from colorectal cancer (CRC) patients and promoted retinoblastoma-cyclin-dependent kinase activation. The aim of the present study was to evaluate the effect of IRS-4 on IGF-1 receptor pathway and its impact on procaspase 3 and PARP expression in RKO and HepG2 cancer cell lines. The results obtained in vitro were compared with those obtained from biopsies of patients with CRC (n = 18), tubulovillous adenomas (TA) (n = 2) and in matched adjacent normal colorectal (MANC) tissue (n = 20). IRS-4 overexpression in cultured cells induced the overactivation of IGF-1/BRK/AKT/GSK-3/β-catenin/cyclin D1 pathways, which led to increased expression of procaspase 3 and PARP protein levels. Studies carried out on CRC and TA tissues revealed the overactivation of the IGF-1 receptor signalling pathway, as well as the overexpression of procaspase 3 and PARP in tumoural tissue with respect to MANC tissue. The upregulation of IRS-4 in tumoural samples correlated significantly with the increase in pIGF-1 receptor (Tyr 1165/1166) (r = 0.84; p < 0.0001), procaspase 3 (r = 0. 77; p < 0. 0005) and PARP (r = 0. 89; p < 0. 0005). Similarly, we observed an increase in the proteolysis of procaspase 3 in tumoural tissue with respect to MANC tissue, which correlated significantly with the degradation of PARP (r = 0.86; p < 0.0001), p53 (r = 0.84; p < 0.0001), and GSK-3 (r = 0.78; p < 0.0001). The stratification of patient samples using the TNM system revealed that procaspase 3 and caspase 3 increased gradually with T values, which suggests their involvement in the size and local invasion of primary tumours. Taken together, our findings suggest that IRS-4 overexpression promotes the activation of the IGF-1 receptor pathway, which leads to the increase in procaspase 3 levels in CRC.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zonghao Tang ◽  
Jiajie Chen ◽  
Zhenghong Zhang ◽  
Jingjing Bi ◽  
Renfeng Xu ◽  
...  

The increase of oxidative stress is one of the important characteristics of mammalian luteal regression. Previous investigations have revealed the essential role of reactive oxygen species (ROS) in luteal cell death during luteolysis, while it is unknown how ROS is regulated in this process. Considering the decrease of blood flow and increase of PGF2α during luteolysis, we hypothesized that the HIF-1α pathway may be involved in the regulation of ROS in the luteal cell of the late corpus luteum (CL). Here, by using a pseudopregnant rat model, we showed that the level of both HIF-1α and its downstream BNIP3 was increased during luteal regression. Consistently, we observed the increase of autophagy level during luteolysis, which is regulated in a Beclin1-independent manner. Comparing with early (Day 7 of pseudopregnancy) and middle CL (Day 14), the level of ROS was significantly increased in late CL, indicating the contribution of oxidative stress in luteolysis. Inhibition of HIF-1α by echinomycin (Ech), a potent HIF-1α inhibitor, ameliorated the upregulation of BNIP3 and NIX, as well as the induction of autophagy and the accumulation of ROS in luteal cells on Day 21 of pseudopregnancy. Morphologically, Ech treatment delayed the atrophy of the luteal structure at the late-luteal stage. An in vitro study indicated that inhibition of HIF-1α can also attenuate PGF2α-induced ROS and luteal cell apoptosis. Furthermore, the decrease of cell apoptosis can also be observed by ROS inhibition under PGF2α treatment. Taken together, our results indicated that HIF-1α signaling is involved in the regression of CL by modulating ROS production via orchestrating autophagy. Inhibition of HIF-1α could obviously hamper the apoptosis of luteal cells and the process of luteal regression.


1987 ◽  
Vol 40 (3) ◽  
pp. 331 ◽  
Author(s):  
William Hansel ◽  
Hector W Alila ◽  
Joseph P Dowd ◽  
Xiangzhong Yang

Evidence was cited to show that: (1) prostacyclin (PGI2) plays a luteotrophic role in the bovine corpus luteum and that products of the lipoxygenase pathway of arachidonic acid metabolism, especially 5-hydroxyeicosatetraenoic acid play luteolytic roles; (2) oxytocin of luteal cell origin plays a role in development, and possibly in regression, of the bovine corpus luteum; and (3) luteal cells arise from two sources; the characteristic small luteal cells at all stages of the o~strous cycle and pregnancy are of theca cell origin; the large cells are of granulosa cell origin early in the cycle, but a population of theca-derived large cells appears later in the cycle. Results of in vitro studies with total dispersed cells and essentially pure preparations of large and small luteal cells indicate that : (1) the recently described Ca2+ -polyphosphoinositol-protein kinase C second messenger system is involved in progesterone synthesis in the bovine corpus luteum; (2) activation of protein kinase C is stimulatory to progesterone synthesis in the small luteal cells; (3) activation of protein kinase C has no effect on progesterone synthesis in the large luteal cells; and (4) protein kinase C exerts its luteotrophic effect in total cell preparations, in part at least, by stimulating the production of prostacyclin. The protein kinase C system may cause down regulation of LH receptors in the large cells.


2019 ◽  
Vol 34 (10) ◽  
pp. 2018-2026 ◽  
Author(s):  
Lanlan Fang ◽  
Yiping Yu ◽  
Yiran Li ◽  
Sijia Wang ◽  
Ruizhe Zhang ◽  
...  

Abstract STUDY QUESTION Does amphiregulin (AREG), the most abundant and important epidermal growth factor receptor (EGFR) ligand in the follicular fluid, regulate aromatase expression in human granulosa-lutein (hGL) cells? SUMMARY ANSWER AREG mediates the hCG-induced up-regulation of aromatase expression and estradiol (E2) production in hGL cells. WHAT IS KNOWN ALREADY AREG expression and secretion are rapidly induced by hCG in hGL cells and mediate physiological functions of LH/hCG in the ovary. EGFR protein is expressed in follicles not only in the pre-ovulatory phase but also throughout the luteal phase of the menstrual cycle. After the LH surge, the human corpus luteum secretes high levels of E2, which regulates various luteal cell functions. Aromatase is an enzyme responsible for a key step in the biosynthesis of E2. However, whether AREG regulates aromatase expression and E2 production in hGL cells remains unexplored. STUDY DESIGN, SIZE, DURATION This study is an experimental study performed over a 1-year period. In vitro investigations examined the role of AREG in the regulation of aromatase expression and E2 production in primary hGL cells. PARTICIPANTS/MATERIALS, SETTING, METHODS Primary hGL cells were obtained from women undergoing IVF treatment in an academic research center. Aromatase mRNA and protein levels were examined after exposure of hGL cells to recombinant human AREG, hCG or LH. The EGFR tyrosine kinase inhibitor AG1478, PI3K inhibitor LY294002 and siRNAs targeting EGFR, LH receptor, StAR and AREG were used to verify the specificity of the effects and to investigate the underlying molecular mechanisms. Reverse transcription quantitative real-time PCR (RT-qPCR) and western blot were used to measure the specific mRNA and protein levels, respectively. Follicular fluid and serum were collected from 65 infertile women during IVF treatment. Pearson’s correlation analysis was performed to examine the correlation coefficient between two values. MAIN RESULTS AND THE ROLE OF CHANCE Treatment of hGL cells with AREG-stimulated aromatase expression and E2 production. Using pharmacological inhibitors and specific siRNAs, we revealed that AREG-stimulated aromatase expression and E2 production via EGFR-mediated activation of the protein kinase B (AKT) signaling pathway. In addition, inhibition of EGFR activity and AREG knockdown attenuated hCG-induced up-regulation of aromatase expression and E2 production. Importantly, the protein levels of AREG in the follicular fluid were positively correlated with the E2 levels in serum after 2 days of oocyte pick-up and in the follicular fluid of IVF patients. LARGE-SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION The in vitro setting of this study is a limitation that may not reflect the real intra-ovarian microenvironment. Clinical data were obtained from a small sample size. WIDER IMPLICATIONS OF THE FINDINGS Our results provide the first evidence that hCG-induced AREG contributes to aromatase expression and E2 production in the luteal phase of the menstrual cycle. A better understanding of the hormonal regulation of female reproductive function may help to develop new strategies for the treatment of clinical infertility. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the National Natural Science Foundation of China for Young Scientists (81601253), the specific fund of clinical medical research of Chinese Medical Association (16020160632) and the Foundation from the First Affiliated Hospital of Zhengzhou University for Young Scientists to Lanlan Fang. This work was also supported by an operating grant from the National Natural Science Foundation of China (81820108016) to Ying-Pu Sun. All authors declare no conflict of interest.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
António Galvão ◽  
Angela Tramontano ◽  
Maria Rosa Rebordão ◽  
Ana Amaral ◽  
Pedro Pinto Bravo ◽  
...  

Metabolic hormones have been associated with reproductive function modulation. Thus, the aim of this study was: (i) to characterize the immunolocalization, mRNA and protein levels of leptin (LEP), Ghrelin (GHR) and respective receptors LEPR and Ghr-R1A, throughout luteal phase; and (ii) to evaluate the role of LEP and GHR on progesterone (P4), prostaglandin (PG) E2and PGF2α, nitric oxide (nitrite), tumor necrosis factor-α(TNF); macrophage migration inhibitory factor (MIF) secretion, and on angiogenic activity (BAEC proliferation), in equine corpus luteum (CL) from early and mid-luteal stages. LEPR expression was decreased in late CL, while GHR/Ghr-R1A system was increased in the same stage. Regarding secretory activity, GHR decreased P4in early CL, but increased PGF2α, nitrite and TNF in mid CL. Conversely, LEP increased P4, PGE2, angiogenic activity, MIF, TNF and nitrite during early CL, in a dose-dependent manner. Thein vitroeffect of LEP on secretory activity was reverted by GHR, when both factors acted together. The present results evidence the presence of LEP and GHR systems in the equine CL. Moreover, we suggest that LEP and GHR play opposing roles in equine CL regulation, with LEP supporting luteal establishment and GHR promoting luteal regression. Finally, a dose-dependent luteotrophic effect of LEP was demonstrated.


Reproduction ◽  
2013 ◽  
Vol 146 (3) ◽  
pp. 273-282 ◽  
Author(s):  
S N Schauer ◽  
S D Sontakke ◽  
E D Watson ◽  
C L Esteves ◽  
F X Donadeu

Previous evidence fromin vitrostudies suggests specific roles for a subset of miRNAs, including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, and miR-212, in regulating ovarian follicle development. The objective of this study was to determine changes in the levels of these miRNAs in relation to follicle selection, maturation, and ovulation in the monovular equine ovary. In Experiment 1, follicular fluid was aspirated during ovulatory cycles from the dominant (DO) and largest subordinate (S) follicles of an ovulatory wave and the dominant (DA) follicle of a mid-cycle anovulatory wave (n=6 mares). Follicular fluid levels of progesterone and estradiol were lower (P<0.01) in S follicles than in DO follicles, whereas mean levels of IGF1 were lower (P<0.01) in S and DA follicles than in DO follicles. Relative to DO and DA follicles, S follicles had higher (P≤0.01) follicular fluid levels of miR-145 and miR-378. In Experiment 2, follicular fluid and granulosa cells were aspirated from dominant follicles before (DO) and 24 h after (L) administration of an ovulatory dose of hCG (n=5 mares/group). Relative to DO follicles, L follicles had higher follicular fluid levels of progesterone (P=0.05) and lower granulosa cell levels ofCYP19A1andLHCGR(P<0.005). Levels of miR-21, miR-132, miR-212, and miR-224 were increased (P<0.05) in L follicles; this was associated with reduced expression of the putative miRNA targets,PTEN,RASA1, andSMAD4. These novel results may indicate a physiological involvement of miR-21, miR-145, miR-224, miR-378, miR-132, and miR-212 in the regulation of cell survival, steroidogenesis, and differentiation during follicle selection and ovulation in the monovular ovary.


Steroids ◽  
1976 ◽  
Vol 27 (4) ◽  
pp. 543-551 ◽  
Author(s):  
Richard L. Stouffer ◽  
Wilbert E. Nixon ◽  
Bela J. Gulyas ◽  
David.K. Johnson ◽  
Gary D. Hodgen

1994 ◽  
Vol 142 (1) ◽  
pp. 101-110 ◽  
Author(s):  
G S Menzies ◽  
T A Bramley

Abstract Subcellular fractionation of porcine corpus luteum (CL) homogenates on continuous sucrose gradients has previously demonstrated that most of the endogenous progesterone of the CL was associated with a unique particulate fraction. Exogenous radiolabelled steroids were also sequestered with some specificity by this fraction. We now report that this particulate fraction is capable of binding high levels of exogenous 3H-labelled progesterone (and pregnenolone) in vitro, but only in the presence of the saponin, digitonin. Binding was dependent on the pH, temperature and duration of incubation, and showed specificity and high affinity for progesterone (Kd, 79 nm). Androgens, oestrogens and pregnenolone competed for porcine luteal [3H] progesterone binding sites, but only at much higher concentrations, whereas cholesterol, a number of progesterone receptor agonist and antagonist analogues and inhibitors of 3β-hydroxysteroid dehydrogenase and C17-hydroxylase/C17,20-lyase did not compete. Analysis of profiles for a number of luteal cell-surface membrane and intracellular organelle markers confirmed previous studies showing the association of an NADH-cytochrome C reductase with this fraction. Moreover, the content of endogenous progesterone associated with particulate subcellular fractions isolated from porcine granulosa cell (GC) and CL homogenates at different stages of the luteal phase and early pregnancy waxed and waned with the stage of the luteal phase (and the secretory activity of the CL). Binding of [3H]progesterone in vitro equilibrated at the same buoyant density as endogenous progesterone: levels of both were highest during the mid-luteal phase and during early pregnancy, lower in early and late luteal CL, and undetectable in corpora albicantia. In contrast, relaxin secretory granules were readily resolved from progesterone binding sites. We propose that these particulate progesterone binding sites may be involved in the sequestration and/or packaging of newly-synthesized steroid for secretion by the luteal cell, or may mediate actions of progesterone within the luteal cell. Journal of Endocrinology (1994) 142, 101–110


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