Reconsideration of the proposed luteotropic and luteoprotective actions of ovine placental lactogen in sheep: in vivo and in vitro studies

Al-Gubory, Kaïs Hussain; Camous, Sylvaine; Germain, Guy; Bolifraud, Philippe; Nicole, Annie; Ceballos-Picot, Irène

doi:10.1677/joe.1.06550

Cited by 17 publications

(9 citation statements)

References 56 publications

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“…Placentome ethanol extracts were analyzed for progesterone content in duplicate by a RIA as previously described (Schanbacher 1979) and validated for sheep jugular venous plasma with slight modifications (Al-Gubory et al 2006). Briefly, dextran-coated charcoal solution was used instead of polyethylene glycol for the separation of bound and free radioactivity.…”

Section: Progesterone Riamentioning

confidence: 99%

Developmental changes in antioxidant enzymatic defences against oxidative stress in sheep placentomes

Garrel¹,

Fowler²,

Al-Gubory³

2010

Journal of Endocrinology

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Early pregnancy is susceptible to oxidative stress, and thus characterisation of antioxidant systems and pro-and antiapoptotic pathways would improve understanding of placental development and function. We aimed, therefore, to determine the activities of the antioxidant enzymes, copper/zinc-superoxide dismutase (SOD1), manganese-SOD (SOD2), catalase (CAT), glutathione (GSH) peroxidase (GPX) and GSH reductase (GSR); and to quantify the expression of BAX and MCL1 proteins in relation to the developmental changes in antioxidant defences in sheep placentomes sampled on days 35, 55 and 80 of pregnancy. Placentome progesterone content was analyzed to determine steroidogenic capacity. Malondialdehyde (MDA) and protein carbonyl were quantified in placentomes as biomarkers of lipid peroxidation and protein damage respectively. Placentome tissues demonstrated significantly increased content of progesterone and MDA at day 80 of pregnancy and protein carbonyl as early as day 50 of pregnancy. Progesterone and MDA contents were not different between days 35 and 55 of pregnancy. While SOD1 and CAT activities did not alter significantly, SOD2 activity decreased from days 35 to 55. GPX activity increased from days 35 to 55 and increased further to day 80 of pregnancy. GSR activity increased from days 35 to 55 of pregnancy. BAX protein expression decreased, while MCL1 increased from days 35 to 55 and 80 of pregnancy. The increased GPX activity was associated with a decrease in the BAX/MCL1 protein expression ratio. Changes in the antioxidant enzymatic defences could be a part of placentome adaptation to reactive oxygen speciesinduced oxidative stress at specific early developmental stages of pregnancy.

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Section: Progesterone Riamentioning

confidence: 99%

Developmental changes in antioxidant enzymatic defences against oxidative stress in sheep placentomes

Garrel¹,

Fowler²,

Al-Gubory³

2010

Journal of Endocrinology

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“…1) with an instrument equipped with a 7-14 MHz linear transducer. The milk vein was recognized in all ewes in B-mode and confirmed as a vessel when the cross-section of the vessel averaged 24.22 ± 5.21 mm 2 . Blood flow waveforms were obtained at an interrogation angle of 60° to 80° between the Doppler ultrasound beam and the flow direction.…”

Section: Fig 1 Usg Of Ewe Right Mammary Vein (Rmv) Before Parturitimentioning

confidence: 80%

“…However, there are conflicting results in respect to the luteoprotective role of oPL. According to Gregoraszczuk et al (11), oPL has luteoprotective effects, but according to Al-Gubory et al (2), it is impossible to demonstrate such effects.…”

mentioning

confidence: 99%

Relationship between mammary blood flow, infrared thermography and ovine placental lactogen during the periparturient period in ewes

Bobowiec

Wójcik

Milczak

et al. 2019

Medycyna Weterynaryjna

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The aim of the study to verify the hypothesis whether a drop in the oPL levels in the blood in the periparturient period is associated with changes in the right mammary vein blood flow (RMVBF) and udder skin temperature (UST). We were also interested in comparing variations in the above-mentioned parameters in single- and twin-pregnant ewes. Beginning six days before parturition (-6th day) until four days postpartum (4th day), every second day each of 15 experimental pregnant ewes was subjected to color Doppler ultrasound performed with continuous wave-equipment (My Lab One/Touch) and infrared thermography (IRT), which allowed for noninvasive collection of data. Plasma oPL levels were determined using quantitative sandwich ELISA Kit specified for sheep placental lactogen 1 (oPL). The measured values of UST were affected by the periparturient period but not by the number of lambs delivered. The highest udder temperatures were recorded at four days before parturition, which was followed by their gradual decrease. As a result, UST achieved the lowest values in single- and also in twin-pregnant ewes on the day of parturition (35.70 ± 0.65°C and 35.42 ± 0.45°C, respectively). Among all the time points of measuring IRT and oPL, a significant positive correlation (P≤0.01) was estimated at -4 and 0 days before parturition for single- (r= 0.99) and twin- (r= 0.59) pregnant ewes. In comparison to control ewes, right mammary vein blood flow (RMVBF) significantly (P≤0.05) increased in all pregnant ewes under study. Especially in twin-pregnant ewes, a positive correlation between the plasma concentration of oPL and blood flow occurred between the -4th and 0 day (r = 0.76). Maximal velocity of blood flow in the mammary vein in single- (25.90 ± 5.95 cm/s) and twin-pregnant ewes (24.62 ± 4.86 cm/s) was recorded at the 2nd and 4th day postpartum, respectively. The highest values of plasma oPL (0.56 ± 0.05 µg/ml) recorded at the beginning of the experimental period (-6 days before parturition) dropped significantly (P≤0.05) during the subsequent days, until parturition. The curve of the temporal changes in the concentrations of plasma oPL remains unchanged regardless of the number of fetuses. Three-phasic thermal changes in the periparturient period and an increase in blood flow parameters are related to the disappearance of oPL from the circulation, which should be taken into account when assessing a pathological state of this gland.

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“…In order to mimic the ovarian oestrous cycle, ovariectomized ewes were supplemented for 12 days with control solution (control group) or ovarian steroid solutions (P4, E2 or a combination of both) [57]. A group of cyclic ewes at 12 days post-oestrus was included in the experimental design in order to determine the effect of ovariectomy on endometrial gene expression.…”

Section: Endometrial Foxl2 Gene Expression Varies With Blood P4 Concementioning

confidence: 99%

FOXL2 is a Progesterone Target Gene in the Endometrium of Ruminants

Eozénou

Lesage-Padilla

Mauffré

et al. 2020

IJMS

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Forkhead Box L2 (FOXL2) is a member of the FOXL class of transcription factors, which are essential for ovarian differentiation and function. In the endometrium, FOXL2 is also thought to be important in cattle; however, it is not clear how its expression is regulated. The maternal recognition of pregnancy signal in cattle, interferon-Tau, does not regulate FOXL2 expression. Therefore, in the present study, we examined whether the ovarian steroid hormones that orchestrate implantation regulate FOXL2 gene expression in ruminants. In sheep, we confirmed that FOXL2 mRNA and protein was expressed in the endometrium across the oestrous cycle (day 4 to day 15 post-oestrus). Similar to the bovine endometrium, ovine FOXL2 endometrial expression was low during the luteal phase of the oestrous cycle (4 to 12 days post-oestrus) and at implantation (15 days post-oestrus) while mRNA and protein expression significantly increased during the luteolytic phase (day 15 post-oestrus in cycle). In pregnant ewes, inhibition of progesterone production by trilostane during the day 5 to 16 period prevented the rise in progesterone concentrations and led to a significant increase of FOXL2 expression in caruncles compared with the control group (1.4-fold, p < 0.05). Ovariectomized ewes or cows that were supplemented with exogenous progesterone for 12 days or 6 days, respectively, had lower endometrial FOXL2 expression compared with control ovariectomized females (sheep, mRNA, 1.8-fold; protein, 2.4-fold; cattle; mRNA, 2.2-fold; p < 0.05). Exogenous oestradiol treatments for 12 days in sheep or 2 days in cattle did not affect FOXL2 endometrial expression compared with control ovariectomized females, except at the protein level in both endometrial areas in the sheep. Moreover, treating bovine endometrial explants with exogenous progesterone for 48h reduced FOXL2 expression. Using in vitro assays with COS7 cells we also demonstrated that progesterone regulates the FOXL2 promoter activity through the progesterone receptor. Collectively, our findings imply that endometrial FOXL2 is, as a direct target of progesterone, involved in early pregnancy and implantation.

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Reconsideration of the proposed luteotropic and luteoprotective actions of ovine placental lactogen in sheep: in vivo and in vitro studies

Cited by 17 publications

References 56 publications

Developmental changes in antioxidant enzymatic defences against oxidative stress in sheep placentomes

Developmental changes in antioxidant enzymatic defences against oxidative stress in sheep placentomes

Relationship between mammary blood flow, infrared thermography and ovine placental lactogen during the periparturient period in ewes

FOXL2 is a Progesterone Target Gene in the Endometrium of Ruminants

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