scholarly journals Role of gap junctions in regulation of progesterone secretion by ovine luteal cells in vitro

Reproduction ◽  
2007 ◽  
Vol 133 (3) ◽  
pp. 641-651 ◽  
Author(s):  
Ewa Borowczyk ◽  
Mary Lynn Johnson ◽  
Jerzy J Bilski ◽  
Magda A Bilska ◽  
Dale A Redmer ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Mrna Expression ◽  
Estrous Cycle ◽  
Luteal Cell ◽  
Gap Junctional Intercellular Communication ◽  
Luteal Cells ◽  
Progesterone Secretion ◽  
Cx43 Mrna

To evaluate the role of gap junctions in the regulation of progesterone secretion, two experiments were conducted. In Experiment 1, luteal cells obtained on days 5, 10, and 15 were cultured overnight at densities of 50×103, 100×103, 300×103, and 600×103cells/dish in medium containing: (1) no treatment (control), (2) LH, or (3) dbcAMP. In Experiment 2, luteal cells from days 5 and 10 of the estrous cycle were transfected with siRNA, which targeted the connexin (Cx) 43 gene. In Experiment 1, progesterone secretion, Cx43 mRNA expression, and the rates of gap junctional intercellular communication (GJIC), were affected by the day of the estrous cycle, cell density, and treatments (LH or dbcAMP). The changes in progesterone secretion were positively correlated with the changes in Cx43 mRNA expression and the rates of GJIC. Cx43 was detected on the luteal cell borders in every culture, and luteal cells expressed 3β-hydroxysteroid dehydrogenase. In Experiment 2, twoCx43gene-targeted sequences decreased Cx43 mRNA expression and progesterone production by luteal cells. The changes in Cx43 mRNA expression were positively correlated with changes in progesterone concentration in media. Thus, our data demonstrate a relationship between gap junctions and progesterone secretion that was supported by (1) the positive correlations between progesterone secretion and Cx43 mRNA expression and GJIC of luteal cells and (2) the inhibition of Cx43 mRNA expression by siRNA that resulted in decreased production of progesterone by luteal cells. This suggests that gap junctions may be involved in the regulation of steroidogenesis in the ovine corpus luteum.

scholarly journals HIF-1α Activation Promotes Luteolysis by Enhancing ROS Levels in the Corpus Luteum of Pseudopregnant Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zonghao Tang ◽  
Jiajie Chen ◽  
Zhenghong Zhang ◽  
Jingjing Bi ◽  
Renfeng Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Corpus Luteum ◽  
Cell Apoptosis ◽  
In Vitro Study ◽  
Luteal Cell ◽  
Independent Manner ◽  
Luteal Regression ◽  
Luteal Cells

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.

Does prostacyclin (PGI2) support porcine corpus luteum function? – data from in vitro study

2016 ◽  
Vol 62 (5) ◽  
pp. 49
Author(s):  
Magdalena Julia Szymańska ◽  
Agnieszka Blitek
Keyword(s):  
Endothelial Cells ◽  
Mrna Expression ◽  
Corpus Luteum ◽  
Estrous Cycle ◽  
In Vitro Study ◽  
Luteal Cells ◽  
Enzymatic Isolation ◽  
Effective Doses ◽  
And Function

Background. Prostacyclin (PGI2) of luteal origin is involved in the control of corpus luteum (CL) development and function in cattle. PGI2 may regulate the process of angiogenesis and may stimulate progesterone (P4) secretion by luteal cells via its specific receptors, PTGIR. In contrast to cattle, the role of PGI2 in the pig CL has not yet been described.Aim. The present study aimed to investigate the effect of PGI2 on 1) P4 secretion by luteal cells, and 2) the expression of angiogenesis-related genes in endothelial cells of the porcine CL.Methods. CL collected from gilts on day 5-7 of the estrous cycle were used for enzymatic isolation of luteal (Experiment 1) and endothelial (Experiment 2) cells. In Exp. 1, cultured luteal cells were incubated with increasing (0, 0.01, 0.1, 1, 5 µM) doses of PGI2 analogues: iloprost (ILO) and carbaprostacyclin (cPGI2) for 8 h. To determine the effective doses of PGI2 analogues, P4 concentration in culture medium was examined by RIA. Thereafter, luteal cells were treated with ILO and cPGI2 at the concentration of 1 and 5 µM in the presence or absence of PTGIR antagonist (CAY10441). After 8 h of incubation the medium was collected for P4 determination. In Exp. 2, isolated endothelial cells were treated for 24 h with ILO and cPGI2 at doses of 1 and 5 µM. Then, cells were collected for analysis of Ang-1 and -2 mRNA expression using qPCR.Results. Both, ILO and cPGI2 affected P4 secretion by luteal cells. Elevated levels of P4 were observed in medium after treatment of luteal cells with 1 µM of ILO and 0.1, 1 and 5 µM of cPGI2 compared with control values (p<0.05). The addition of CAY10441 inhibited the stimulatory effect of ILO on P4 secretion, while did not change P4 production by luteal cells incubated with cPGI2. Moreover, PGI2 analogues differentially affected (p<0.05) the expression of proangiogenic factors. ILO stimulated Ang-2, whereas cPGI2 positively affected Ang-1 mRNA expression in endothelial cells at concentrations of 1 µM and 5 µM, respectively.Conclusion. PGI2 affects P4 secretion during luteal phase of the estrous cycle and may regulate the process of angiogenesis in the porcine CL.

scholarly journals Leukotrienes modulate secretion of progesterone and prostaglandins during the estrous cycle and early pregnancy in cattle: an in vivo study

Reproduction ◽  
2010 ◽  
Vol 140 (5) ◽  
pp. 767-776 ◽  
Author(s):  
Anna J Korzekwa ◽  
Mamadou M Bah ◽  
Andrzej Kurzynowski ◽  
Karolina Lukasik ◽  
Agnieszka Groblewska ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Estrous Cycle ◽  
Early Pregnancy ◽  
Luteal Phase ◽  
Reproductive Tract ◽  
Cell Function ◽  
Ovarian Cell

Recently, we showed that leukotrienes (LTs) regulate ovarian cell functionin vitro. The aim of this study was to examine the role of LTs in corpus luteum (CL) function during both the estrous cycle and early pregnancyin vivo. mRNA expression of LT receptors (BLTfor LTB4andCYSLTfor LTC4), and 5-lipoxygenase (5-LO) in CL tissue and their localization in the ovary were studied during the estrous cycle and early pregnancy. Moreover, concentrations of LTs (LTB4and C4) in the CL tissue and blood were measured.5-LOandBLTmRNA expression increased on days 16–18 of the cycle, whereasCYSLTmRNA expression increased on days 16–18 of the pregnancy. The level of LTB4was evaluated during pregnancy compared with the level of LTC4, which increased during CL regression. LT antagonists influenced the duration of the estrous cycle: the LTC4antagonist (azelastine) prolonged the luteal phase, whereas the LTB4antagonist (dapsone) caused earlier luteolysisin vivo. Dapsone decreased progesterone (P4) secretion and azelastine increased P4secretion during the estrous cycle. In summary, LT action in the bovine reproductive tract is dependent on LT type: LTB4is luteotropic during the estrous cycle and supports early pregnancy, whereas LTC4is luteolytic, regarded as undesirable in early pregnancy. LTs are produced/secreted in the CL tissue, influence prostaglandin function, and serve as important factors during the estrous cycle and early pregnancy in cattle.

Role of phosphoprotein phosphatases in the corpus luteum: I Identification and characterisation of serine/threonine phosphoprotein phosphatases in isolated rat luteal cells

1996 ◽  
Vol 150 (2) ◽  
pp. 205-211 ◽  
Author(s):  
S L Ford ◽  
D R E Abayasekara ◽  
S J Persaud ◽  
P M Jones
Keyword(s):  
Polyclonal Antibodies ◽  
Luteal Cell ◽  
Luteal Cells ◽  
Cell Functions ◽  
Phosphoprotein Phosphatases ◽  
Sds Page ◽  
Molecular Masses ◽  
Dose Dependent Decrease

Abstract Although the role of protein kinases and phosphorylation in steroidogenesis has received much attention, very little is known about the activities of phosphoprotein phosphatases (PP) and dephosphorylation in steroidogenic tissues. The aims of the present study were therefore to identify which of those serine/threonine PPs more commonly involved in intracellular signalling are expressed in rat luteal cells; to quantify, in vitro, the effects of inhibitors on PP activity extracted from purified rat luteal cells; and to measure the effects of PP inhibitors on the phosphorylation of endogenous luteal cell proteins. Polyclonal antibodies raised against the catalytic subunits of PP types 1 and 2A, and a monoclonal antibody raised against the Ca2+-binding subunit of PP2B, were used to identify immunoreactive proteins that migrated on SDS-PAGE with approximate molecular masses of 37, 34 and 16 kDa, corresponding well with the reported molecular mass of PP1, PP2A and PP2B respectively. Five selective inhibitors of PP1/PP2A: okadaic acid, calyculin A, cantharidin, tautomycin and microcystin-RR, each caused a dose-dependent decrease in the activity of PPs in luteal cell homogenates, and also enhanced 32P incorporation into numerous luteal cell proteins; most notably, proteins with approximate molecular masses of 20 and 22 kDa. The results of this study suggest that PPs may play an important role in the regulation of rat luteal cell functions. Journal of Endocrinology (1996) 150, 205–211

scholarly journals Deciphering the functional role of EGR1 in Prostaglandin F2 alpha induced luteal regression applying CRISPR in corpus luteum of buffalo

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Meeti Punetha ◽  
Sai Kumar ◽  
Avishek Paul ◽  
Bosco Jose ◽  
Jaya Bharati ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Corpus Luteum ◽  
Caspase 3 ◽  
Cellular Proliferation ◽  
Luteal Cell ◽  
Wild Type ◽  
Luteal Regression ◽  
Luteal Cells ◽  
Prostaglandin F2 Alpha

Abstract Background PGF2α is essential for the induction of the corpus luteum regression which in turn reduces progesterone production. Early growth response (EGR) proteins are Cys2-His2-type zinc-finger transcription factor that are strongly linked to cellular proliferation, survival and apoptosis. Rapid elevation of EGR1 was observed after luteolytic dose of PGF2α. EGR1 is involved in the transactivation of many genes, including TGFβ1, which plays an important role during luteal regression. Methods The current study was conducted in buffalo luteal cells with the aim to better understand the role of EGR1 in transactivation of TGFβ1 during PGF2α induced luteal regression. Luteal cells from mid stage corpus luteum of buffalo were cultured and treated with different doses of PGF2α for different time durations. Relative expression of mRNAs encoding for enzymes within the progesterone biosynthetic pathway (3βHSD, CYP11A1 and StAR); Caspase 3; AKT were analyzed to confirm the occurrence of luteolytic event. To determine if EGR1 is involved in the PGF2α induced luteal regression via induction of TGFβ1 expression, we knocked out the EGR1 gene by using CRISPR/Cas9. Result The present experiment determined whether EGR1 protein expression in luteal cells was responsive to PGF2α treatment. Quantification of EGR1 and TGFβ1 mRNA showed significant up regulation in luteal cells of buffalo at 12 h post PGF2α induction. In order to validate the role of PGF2α on stimulating the expression of TGFβ1 by an EGR1 dependent mechanism we knocked out EGR1. The EGR1 ablated luteal cells were stimulated with PGF2α and it was observed that EGR1 KO did not modulate the PGF2α induced expression of TGFβ1. In PGF2α treated EGR1 KO luteal cell, the mRNA expression of Caspase 3 was significantly increased compared to PGF2α treated wild type luteal cells maintained for 12 h. We also studied the influence of EGR1 on steroidogenesis. The EGR1 KO luteal cells with PGF2α treatment showed no substantial difference either in the progesterone concentration or in StAR mRNA expression with PGF2α-treated wild type luteal cells. Conclusion These results suggest that EGR1 signaling is not the only factor which plays a role in the regulation of PGF2α induced TGFβ1 signaling for luteolysis.

Functional luteolysis in response to hydrogen peroxide in human luteal cells

1995 ◽  
Vol 147 (1) ◽  
pp. 177-182 ◽  
Author(s):  
M Vega ◽  
I Carrasco ◽  
T Castillo ◽  
J L Troncoso ◽  
L A Videla ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Cultures ◽  
Specific Binding ◽  
Luteal Cell ◽  
Luteal Cells ◽  
Dose Dependent Decrease ◽  
Dose Dependent ◽  
Human Corpus Luteum

Abstract To evaluate the effect of reactive oxygen species in human corpus luteum function, we investigated whether hydrogen peroxide (H2O2) affects the in vitro luteal cell production of steroids. H2O2 treatment (1·0–100 μm) of mid and late luteal cell cultures elicited a dose-dependent decrease in basal progesterone production. However, treatment of mid luteal cells with a low concentration of H2O2 0·01 μm) significantly stimulated progesterone secretion (P<0·05). In addition, H2O2 (100 μm) markedly inhibited human chorionic gonadotropin (hCG)-stimulated progesterone and estradiol secretion. cAMP production was enhanced (2·4-fold, P<0·05) by hCG treatment of luteal cells. The addition of H2O2 (0·1–100 μm) to hCG-stimulated luteal cell cultures elicited a decrease in cAMP concentration (P<0·05) and in the specific binding of radiolabeled hCG by luteal cells. Progesterone and estradiol production stimulated by dibutyryl cAMP were significantly inhibited by H2O2 (P<0·05). These findings suggest that H2O2 interferes with basal steroid production and, in hCG-stimulated conditions, it may inactivate the gonadotropin–receptor complex. The anti-steroidogenic action of H2O2 therefore raises the possibility of a modulatory role of H2O2 in human luteal steroidogenesis. Journal of Endocrinology (1995) 147, 177–182

Role of phosphoprotein phosphatases in the corpus luteum: II Control of progesterone secretion by isolated rat luteal cells

1996 ◽  
Vol 150 (2) ◽  
pp. 213-221 ◽  
Author(s):  
D R E Abayasekara ◽  
S L Ford ◽  
S J Persaud ◽  
P M Jones
Keyword(s):  
Cyclic Amp ◽  
Okadaic Acid ◽  
Luteal Cell ◽  
Steroidogenic Enzymes ◽  
Luteal Cells ◽  
Phosphoprotein Phosphatases ◽  
Progesterone Secretion ◽  
Dependent Inhibition ◽  
And Function

Abstract The key role of protein kinases and protein phosphorylation in the regulation of luteal steroidogenesis is well documented. However the role of phosphoprotein phosphatases (PP) and dephosphorylation in the regulation of luteal cell progesterone secretion is as yet unknown. We have recently demonstrated the presence and activity of PP1 and PP2A in rat luteal cells and the present study was undertaken to determine the consequences of inhibiting PP activity in terms of progesterone secretion. Three structurally dissimilar inhibitors of PP1/2A, okadaic acid, calyculin A and cantharidin each caused a dose-dependent inhibition of LH-induced progesterone secretion without affecting cyclic AMP accumulation. The less potent derivative of okadaic acid, norokadaone, had no effect on either parameter, suggesting that the inhibitory actions on progesterone secretion are due to their specific actions on PP activity and that this inhibition occurs principally at a locus which is distal to the generation of cyclic AMP. In contrast to the inhibitory effects of PP1/2A inhibitors on progesterone biosynthesis, a PP2B inhibitor, cypermethrin, had no effect on LH-stimulated steroidogenesis. The three PP1/2A inhibitors also caused a concentration-dependent inhibition of dibutyryl cyclic AMP-stimulated progesterone secretion. However, none of the inhibitors affected 22R-hydroxycholesterol-supported steroidogenesis, clearly demonstrating that the inhibitors did not interfere with the activity of steroidogenic enzymes. These results suggest that cycles of phosphorylation/dephosphorylation of specific proteins are required for the sustained production of progesterone. Whilst the precise location and function of putative PP substrates is uncertain, the present results indicate that they are involved in regulating the availability of free cholesterol to steroidogenic enzymes within mitochondria. Journal of Endocrinology (1996) 150, 213–221

Contrasting effects of prolactin on luteal and follicular steroidogenesis

1985 ◽  
Vol 104 (2) ◽  
pp. 241-250 ◽  
Author(s):  
B. Kalison ◽  
M. L. Warshaw ◽  
G. Gibori
Keyword(s):  
Luteal Cell ◽  
Corpora Lutea ◽  
Aromatase Activity ◽  
Luteal Cells ◽  
Progesterone Production ◽  
Progesterone Secretion ◽  
Hypophysectomized Rats ◽  
Stimulation Of

ABSTRACT To determine whether prolactin affects both luteal and follicular production of testosterone and oestradiol, pseudopregnant rats, either intact or hypophysectomized on day 8, were injected daily between days 8 and 9 with 1·5 i.u. human chorionic gonadotrophin (hCG), 250 μg prolactin or a combination of both. Control rats were given vehicle. On day 9, blood was obtained from the ovarian vein and corpora lutea and follicles were isolated and incubated in vitro for 2 h. Administration of hCG to intact rats increased ovarian secretion of testosterone and oestradiol dramatically, but did not affect progesterone secretion. Hypophysectomy on day 8 of pseudopregnancy was followed by a drop in ovarian steroid secretion. Prolactin treatment of hypophysectomized rats markedly enhanced progesterone production but had no stimulatory effect on either testosterone or oestradiol. In contrast, hCG dramatically enhanced ovarian secretion of both testosterone and oestradiol without affecting progesterone secretion. Prolactin administered together with hCG antagonized the stimulation of both testosterone and oestradiol secretion by hCG, yet increased progesterone production. When the specific effects of hCG and prolactin administration on follicles and corpora lutea were studied separately, it was found that hCG treatment in vivo greatly stimulated testosterone and oestradiol production by both tissues in vitro. Since hCG only marginally affected aromatase activity in the follicle, had no effect on aromatase activity in luteal cells and did not increase progesterone synthesis, it appears that hCG acts to increase the formation of androgen substrate for oestradiol biosynthesis. Prolactin, administered with or without hCG, inhibited both basal and hCG-stimulated testosterone and oestradiol synthesis by the follicle. In sharp contrast to its inhibitory effect on follicular production of steroids, prolactin appears to be essential for LH stimulation of testosterone and oestradiol by the corpus luteum. In the absence of prolactin, luteal cells gradually ceased to respond to LH and decreased their output of testosterone and oestradiol. Prolactin administration to hypophysectomized rats did not affect luteal cell production of either steroid. However, corpora lutea of rats treated with prolactin responded to the hCG challenge with an increase in testosterone and oestradiol synthesis. In summary, results of this investigation demonstrate that prolactin affects follicular and luteal production of testosterone and oestradiol in opposite ways. It acts on the follicle to inhibit both basal and LH-stimulated production of testosterone and oestradiol, yet it markedly enhances LH stimulation of testosterone and oestradiol synthesis by luteal cells. J. Endocr. (1985) 104, 241–250

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