scholarly journals Luteal ANGPT-TIE system during selected stages of pregnancy, and normal and antigestagen-induced luteolysis in the dog.

Reproduction ◽  
2018 ◽  
Author(s):  
Aykut Gram ◽  
Miguel Tavares Pereira ◽  
Alois Boos ◽  
Anna T Grazul-Bilska ◽  
Mariusz P. Kowalewski
Keyword(s):  
Corpus Luteum ◽  
Blood Vessels ◽  
Luteal Phase ◽  
Vascular Network ◽  
Network Development ◽  
Luteal Cells ◽  
Time Points ◽  
Tunica Media ◽  
Post Implantation ◽  
Tunica Intima

Rapid establishment of a vascular network is essential for normal functionality of the corpus luteum (CL). The early luteal phase is associated with increased expression of the VEGF-system in canine CL. Acting in synchrony with angiopoietins (ANGPTs), VEGF-system plays major roles in stabilization of blood vessels. However, the expression of the ANPGT-system has not yet been investigated in the dog. Therefore, here, we investigated the luteal expression of ANGPT1, -2, and of their receptors TIE1 and -2, in pregnant dogs at selected time points during pregnancy and at normal and antigestagen-induced luteolysis. Additionally, luteal cells from early CL were incubated with PGE2 and its effects on the ANGPT-system were assessed. Whereas the luteal ANGPT1 was stable until mid-gestation, TIE1 was elevated post-implantation, their expression decreased towards prepartum luteolysis. The ANGPT2- and TIE2-mRNA did not vary during pregnancy. The ANGPT2/ANGPT1 ratio was elevated during prepartum luteolysis. PGE2 increased ANGPT2, but suppressed ANGPT1 levels. None of the ANGPT-system members was affected by antigestagen treatment in mid-pregnancy. Localization of ANGPT1 was predominantly found in the tunica intima and media of vessels and ANGPT2 stained strongly in luteal cells. Both ANGPTs were localized in macrophages. TIE1 stained in the vascular tunica media, in luteal cells and macrophages, whereas TIE2 was colocalized with ANGPT1 in vascular components. In conclusion, high expression of ANGPT1 during the increased presence of VEGFA in early canine CL implies its contribution to vascular network development. The upregulation of the ANGPT2/ANGPT1 ratio during prepartum luteolysis indicates involvement of the ANGPT-system in PGF2a-mediated vascular destabilization.

scholarly journals Immunohistological Localization and Expression of α-Actin in the Baboon (Papio anubis) Corpus Luteum

1997 ◽  
Vol 45 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Firyal S. Khan-Dawood ◽  
Jun Yang ◽  
M. Yusoff Dawood
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Adherens Junctions ◽  
Tunica Albuginea ◽  
Corpora Lutea ◽  
Papio Anubis ◽  
Lh Surge ◽  
Luteal Cells ◽  
Steroidogenic Cells ◽  
E Cadherin

We have recently shown the presence of E-cadherin and of α- and γ-catenins in human and baboon corpora lutea. These are components of adherens junctions between cells. The cytoplasmic catenins link the cell membrane-associated cadherins to the actin-based cytoskeleton. This interaction is necessary for the functional activity of the E-cad-herins. Our aim therefore was to determine the presence of α-actin in the baboon corpus luteum, to further establish whether the necessary components for E-cadherin activity are present in this tissue. An antibody specific for the smooth muscle isoform of actin, α-actin, was used for these studies. The results using immunohistochemistry show that (a) α-actin is present in steroidogenic cells of the active corpus luteum, theca externa of the corpus luteum, cells of the vasculature, and the tunica albuginea surrounding the ovary. The intensity of immunoreactivity for α-actin varied, with the cells of the vasculature reacting more intensely than the luteal cells. A difference in intensity of immunoreactivity was also observed among the luteal cells, with the inner granulosa cells showing stronger immunoreactivity than the peripheral theca lutein cells. There was no detectable immunoreactivity in the steroidogenic cells of the atretic corpus luteum. However, in both the active and atretic corpora lutea, α-actin-positive vascular cells were dispersed within the tissue. (b) Total α-actin (luteal and non-luteal), as determined by Western blot analyses, does not change during the luteal phase and subsequent corpus luteum demise (atretic corpora lutea). (c) hCG stimulated the expression of α-actin and progesterone secretion by the early luteal phase (LH surge + 1–5 days) and midluteal phase (LH surge + 6–10 days) cells in culture, but only progesterone in the late luteal phase (LH surge + 11–15 days). The data show that α-actin is present in luteal cells and that its expression is regulated by hCG, thus suggesting that E-cadherin may form functional adherens junctions in the corpus luteum.

scholarly journals Immunolocalization of steroidogenic enzymes in the corpus luteum and placenta of the Japanese black bear, Ursus thibetanus japonicus, during pregnancy

Reproduction ◽  
2001 ◽  
pp. 587-594 ◽  
Author(s):  
T Tsubota ◽  
S Taki ◽  
K Nakayama ◽  
JI Mason ◽  
S Kominami ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Corpus Luteum ◽  
Fetal Development ◽  
Black Bear ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Ursus Thibetanus ◽  
Delayed Implantation ◽  
Post Implantation ◽  
Implantation Period

The Japanese black bear, Ursus thibetanus japonicus, is a seasonal breeder and shows delayed implantation for several months during pregnancy. The objective of this study was to clarify the steroidogenic capability of the corpus luteum and placenta during pregnancy, including both delayed implantation and fetal development, by immunolocalization of steroidogenic enzymes in these organs of the Japanese black bear. Ovaries and placentae from 15 wild Japanese black bears, which had been killed legally by hunters and were thought to be pregnant, were used in an immunocytochemical study to localize the cholesterol side chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase (3betaHSD), 17alpha-hydroxylase cytochrome P450 (P450c17) and aromatase cytochrome P450 (P450arom) by the avidin-biotin-peroxidase complex method using polyclonal antisera raised in mammals against P450scc, 3betaHSD, P450c17 and P450arom. P450scc and 3betaHSD were localized in all luteal cells throughout pregnancy. P450c17 was present in a few luteal cells, especially in the outer area of the corpus luteum throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. Cells positively immunostained for P450c17 were significantly smaller than negatively immunostained cells (P < 0.01). P450arom was present sporadically in a few luteal cells throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. The size of cells positively immunostained for P450arom was not significantly different from that of negatively immunostained cells. The whole placenta was negatively immunostained for P450scc, 3betaHSD and P450c17, but P450arom was present in the syncytiotrophoblasts and endothelial cells of maternal blood vessels. These results indicate that, in the Japanese black bear, corpora lutea are a source of progesterone which may play an important role in the maintenance of delayed implantation and fetal development during pregnancy. Corpora lutea have a minimum capability to synthesize androgen in small luteal cells and oestrogen in normal-sized luteal cells during pregnancy, and placentae have the ability to synthesize oestrogen during late pregnancy.

Lack of direct inhibitory action of oxytocin on progesterone production by dispersed cells from human corpus luteum

1985 ◽  
Vol 104 (1) ◽  
pp. 149-151 ◽  
Author(s):  
M. C. Richardson ◽  
G. M. Masson
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Inhibitory Action ◽  
Corpora Lutea ◽  
Luteal Cells ◽  
Menstrual Cycles ◽  
Progesterone Production ◽  
Human Corpus Luteum ◽  
Dispersed Cells

ABSTRACT Suspensions of luteal cells were prepared from samples of human corpora lutea obtained during the luteal phase of menstrual cycles. Addition of oxytocin (1 μmol/l) to the various cell preparations had no effect on either basal production of progesterone or on steroidogenic responses to a range of concentrations of gonadotrophin. J. Endocr. (1985) 104, 149–151

Expression and role of resistin on steroid secretion in the porcine corpus luteum

Reproduction ◽  
2021 ◽  
Author(s):  
Patrycja Kurowska ◽  
Monika Sroka ◽  
Monika Dawid ◽  
Ewa Mlyczyńska ◽  
Natalia Respekta ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Corpus Luteum ◽  
Luteal Phase ◽  
Cell Function ◽  
Orphan Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Luteal Cell ◽  
Steroid Synthesis ◽  
Steroid Secretion ◽  
Luteal Cells

Resistin plays an important role in adipogenesis, obesity, insulin resistance and reproduction. Previous studies showed resistin action on ovarian follicular cells; however, whether resistin regulates steroid secretion in luteal cells is still unknown. Our aim was first to determine the expression of resistin and its potential receptors (tyrosine kinase-like orphan receptor 1 [ROR1] and Toll-like receptor 4 [TLR4]) in the porcine corpus luteum (CL), regulation of its expression, effect on kinases phosphorylation and luteal steroidogenesis. Our results showed that the expression of resistin and its receptors was dependent on the luteal phase and this was at the mRNA level higher in the late compared with the early and middle luteal phase. At the opposite, resistin protein expression was higher in the middle and late compared with the early luteal phase, while ROR1 and TLR4 expression was highest in the early luteal phase. Additionally, we observed cytoplasmic localisation of resistin, ROR1 and TLR4 in small and large luteal cells. We found that luteinising hormone, progesterone (P4), insulin and insulin-like growth factor 1 regulated the protein level of resistin, ROR1 and TLR4. Resistin decreased P4 and increased oestradiol (E2) secretion via changing in steroidogenic enzymes expression and via the activation of protein kinase A (PKA) and mitogen-activated protein kinase (MAP3/1), increased the expression of receptors LHCGR and ESR2 and decreased the expression of PGR. Moreover, resistin decreased PKA phosphorylation and enhanced MAP3/1 phosphorylation. Taken together, resistin could act directly on steroid synthesis and serve as an important factor in in vivo luteal cell function.

Induced luteal regression in the primate: evidence for apoptosis and changes in c-myc protein

1995 ◽  
Vol 147 (1) ◽  
pp. 131-137 ◽  
Author(s):  
H M Fraser ◽  
S F Lunn ◽  
G M Cowen ◽  
P J Illingworth
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Primate Species ◽  
Morphological Evidence ◽  
Molecular Evidence ◽  
Corpora Lutea ◽  
Intense Staining ◽  
Cytoplasmic Staining ◽  
Luteal Regression ◽  
Luteal Cells

Abstract There is increasing molecular evidence that apoptosis is involved in the process of structural luteal regression in non-primate species. Apoptosis is dependent upon the activation of certain proto-oncogenes and c-myc protein has an important regulatory role in this process in some cell types. The aim of the present study was to determine the occurrence and localisation of c-myc protein within the primate corpus luteum, determine changes during induction of luteal regression and examine the corpora lutea for morphological evidence of apoptosis. Ovaries were studied from marmoset monkeys in the late follicular, and in the early, mid and late luteal phases. Luteal regression was induced either by treatment with prostaglandin F2α analogue or GnRH antagonist administered during the mid luteal phase and ovaries obtained 24 and 48 h later. Immunocytochemistry was performed using a monoclonal antibody to the c-myc protein. In pre-ovulatory follicles positive staining was found in the nucleus of a few granulosal cells and in the cytoplasm of thecal cells. c-myc was present in all corpora lutea where it was localised predominantly in the cytoplasm. In early corpora lutea, scattered cells with intense staining were observed in the presence of a majority of moderately or weakly stained cells. In the mid and late luteal phases, corpora lutea were uniformly moderately stained for c-myc. Following induction of luteal regression, nuclear degeneration with condensation and fragmentation indicative of apoptosis was observed. In other luteal cells, increased cytoplasmic volume and dissolution of cellular and nuclear membranes suggested necrosis. After luteal regression the overall intensity of staining for c-myc declined, but was present at high signal concentration in the cytoplasm of those cells whose morphological integrity was best maintained following treatment. In a minority of steroidogenic luteal cells, both nuclear and cytoplasmic staining was observed. These results suggest that after ovulation there appears to be a marked increase in c-myc production in the cytoplasm of the luteal cells of the developing corpus luteum and that c-myc is present throughout the luteal phase. During induced luteal regression c-myc may undergo a transitory rise and transfer to the nucleus and both apoptosis and necrosis occur during the process of luteolysis. Journal of Endocrinology (1995) 147, 131–137

scholarly journals Prostaglandin E2 functions as a luteotrophic factor in the dog

Reproduction ◽  
2013 ◽  
Vol 145 (3) ◽  
pp. 213-226 ◽  
Author(s):  
Mariusz P Kowalewski ◽  
Barbara Fox ◽  
Aykut Gram ◽  
Alois Boos ◽  
Iris Reichler
Keyword(s):  
Luteal Phase ◽  
Regulatory Protein ◽  
Regulatory Mechanisms ◽  
Prostaglandin E ◽  
Luteal Regression ◽  
Luteal Cells ◽  
Progesterone Secretion ◽  
Steroidogenic Acute Regulatory ◽  
Post Implantation

The luteal phase in dogs is governed by many poorly understood regulatory mechanisms. Functioning of the corpus luteum (CL) is unaffected by hysterectomy. Recently, the role of prostaglandins in regulating canine CL function was addressed suggesting a luteotrophic effect of prostaglandin E2 (PGE2) during the early luteal phase. However, compelling functional evidence was lacking. The potential of PGE2 to stimulate steroidogenesis was tested in canine primary luteal cells isolated from developing CL of non-pregnant dogs. In addition, the luteal expression of prostaglandin transporter (PGT) and steroidogenic acute regulatory protein (STAR) was demonstrated and characterized in CL from non-pregnant bitches during the course of dioestrus as well as from pregnant animals during the pre-implantation, post-implantation and mid-gestation periods of pregnancy and during luteolysis; the luteal expression of PGE2 receptors (EP2 and EP4) has been investigated at the protein level throughout pregnancy. Our findings show that PGE2 is an activator of STAR expression in canine luteal cells from early luteal phase, significantly up-regulating STAR promoter activity and protein expression resulting in increased steroidogenesis. The 3βHSD (HSD3B2) and P450scc (CYP11A1) expression remained unaffected by PGE2 treatment. The expression of PGT was confirmed in CL during both pregnancy and dioestrus and generally localized to the luteal cells. After initial up-regulation during the earlier stages of the CL phase, its expression declined towards the luteal regression. Together with the demonstration of EP2 and EP4 throughout pregnancy, and the decline in EP2 at prepartum, our findings further support our hypothesis that intra-luteal PGE2 may play an important role in regulating progesterone secretion in the canine CL.

scholarly journals The role of vaspin in porcine corpus luteum

2020 ◽  
Vol 247 (3) ◽  
pp. 283-294 ◽  
Author(s):  
Patrycja Kurowska ◽  
Ewa Mlyczyńska ◽  
Monika Dawid ◽  
Małgorzata Grzesiak ◽  
Joelle Dupont ◽  
...  
Keyword(s):  
Corpus Luteum ◽  
Hormonal Regulation ◽  
Luteal Phase ◽  
Dependent Manner ◽  
Luteal Cells ◽  
Visceral Adipose ◽  
Dose Dependent ◽  
Late Stages

Vaspin, visceral adipose tissue-derived serine protease inhibitor, plays important roles in inflammation, obesity, and glucose metabolism. Our recent research has shown the expression and role of vaspin in the function of ovarian follicles. However, whether vaspin regulates steroidogenesis and luteolysis in the corpus luteum (CL) is still unknown. The aim of this study was first to determine the expression of vaspin and its receptor GRP78 in porcine CL at the early, middle, and late stages of the luteal phase. Next, we investigated the hormonal regulation of vaspin levels in luteal cells in response to luteinizing hormone (LH), progesterone (P4), and prostaglandin PGE2 and PGF2α. Finally, we determined vaspin’s direct impact on luteal cells steroidogenesis, luteolysis and kinases phosphorylation. Our results are the first to show higher vaspin/GRP78 expression in middle and late vs early stages; immunohistochemistry showed cytoplasmic vaspin/GRP78 localization in small and large luteal cells. In vitro, we found that LH, P4, PGE2, and PGF2α significantly decreased vaspin levels. Furthermore, vaspin stimulated steroidogenesis by the activation of the GRP78 receptor and protein kinase A (PKA). Also, vaspin increased the ratio of luteotropic PGE2 to luteolytic PGF2α secretion via GRP78 and mitogen-activated kinase (MAP3/1). Moreover, vaspin, in a dose-dependent manner, decreased GRP78 expression, while it, in a time-dependent manner, increased kinases PKA and MAPK3/1 phosphorylation. Taken together, we found that vaspin/GRP78 expression depends on the luteal phase stage and vaspin affects luteal cells endocrinology, indicating that vaspin is a new regulator of luteal cells steroidogenesis and CL formation.

Progesterone receptors and proliferating cell nuclear antigen expression in equine luteal tissue

2005 ◽  
Vol 17 (6) ◽  
pp. 659 ◽  
Author(s):  
R. P. Roberto da Costa ◽  
V. Branco ◽  
P. Pessa ◽  
J. Robalo Silva ◽  
G. Ferreira-Dias
Keyword(s):  
Corpus Luteum ◽  
Proliferating Cell Nuclear Antigen ◽  
Luteal Phase ◽  
Progesterone Receptors ◽  
Staining Intensity ◽  
Nuclear Antigen ◽  
Luteal Cell ◽  
Positive Staining ◽  
Luteal Cells ◽  
Proliferating Cell

Steroid hormones act via specific receptors, and these play an important physiological role in the ovary. The objective of this study was to evaluate the cellular distribution of progesterone receptors and their staining intensity in different equine luteal structures during the breeding season, as well as their relationship to luteal cell composition, cell proliferation pattern and plasma progesterone (P4) concentration. There was an increase in proliferating cell nuclear antigen (PCNA) expression in large luteal cells from the corpus hemorrhagicum (CH) to mid-luteal phase, followed by a decrease toward the late luteal stage. In the CH, the number of large luteal cells was lower than in other structures. Only large luteal cells showed positive staining for P4 receptors. An increase in staining intensity for P4 receptors was observed between CH and mid-phase corpus luteum, and CH and late-phase corpus luteum. Synthesis of P4 started at a very early stage of the luteal structure and was accompanied by an increase in P4 receptors and PCNA expression, and proliferation of large luteal cells, until mid-luteal phase. These data suggest that large luteal cells might play an important role in the regulation or synthesis of P4 in equine luteal structures.

Studies on Marsupial Reproduction. 2. The oestrous cycle of Setonix Brachyurus.

1955 ◽  
Vol 3 (1) ◽  
pp. 44 ◽  
Author(s):  
GB Sharman
Keyword(s):  
Corpus Luteum ◽  
Blood Vessels ◽  
Mitotic Activity ◽  
Rapid Growth ◽  
Luteal Phase ◽  
Oestrous Cycle ◽  
Degenerative Changes ◽  
Vaginal Smear ◽  
In The Wild ◽  
Uterine Glands

Setonix brachyurus Quoy and Gaimard is polyoestrous, the length of the cycle being about 28 days. In the wild and in the newly domesticated female, oestrous cycles are resumed in late January after an anoestrous period of 3-5 months. During this period oestrus does not occur and ovary and uterus are shrunken and quiescent. Domestication for periods exceeding 1 yr results in a greatly shortened anoestrous period, culminating in a condition in which oestrus is repeated at regular monthly intervals throughout the year. Pro-oestrus is accompanied by rapid growth of one Graafian follicle, mitotic activity in the uterus, and usually by the onset of cornification in the vaginae and appearance of partly cornified cells in the smear. At oestrus the largest follicle reaches a diameter of almost 3.0 mm. Behavioural oestrus lasts about 12 hr. Ovulation follows 12-24 hr after oestrus and is independent of the act of copulation. Invasion of the collapsed follicle by blood vessels and the growth of a corpus luteum takes place after ovulation. Under the influence of the corpus luteum a luteal phase occurs in the uterus and lasts until about 18 days after oestrus. During the period of activity of the corpus luteum the vaginal smear is almost entirely composed of non-cornified cells and leucocytes. Following the cessation of the luteal phase degenerative changes occur in the uterus and the uterine glands are invaded by leucocytes. The changes during the oestrous cycle in Setonix are compared with those occurring in Didelphis and in other marsupials.

Mitogen-activated protein kinase kinase kinase 8 (MAP3K8) mediates the LH-induced stimulation of progesterone synthesis in the porcine corpus luteum

2019 ◽  
Vol 31 (9) ◽  
pp. 1444
Author(s):  
Di Zhang ◽  
Ying Liu ◽  
Yan Cui ◽  
Sheng Cui
Keyword(s):  
Protein Kinase ◽  
Corpus Luteum ◽  
Luteal Phase ◽  
Kinase Inhibitor ◽  
Mitogen Activated Protein Kinase ◽  
Luteal Cells ◽  
Mitogen Activated Protein ◽  
Porcine Luteal Cells ◽  
Stimulation Of ◽  
Protein Kinase Kinase

Progesterone (P4) synthesized by the corpus luteum (CL) plays a key role in the establishment and maintenance of pregnancy. The LH signal is important for luteinisation and P4 synthesis in pigs. In a previous study, we demonstrated that mitogen-activated protein kinase kinase kinase 8 (MAP3K8) regulates P4 synthesis in mouse CL, but whether the function and mechanism of MAP3K8 in the pig is similar to that in the mouse is not known. Thus, in the present study we investigated the effects of MAP3K8 on porcine CL. Abundant expression of MAP3K8 was detected in porcine CL, and, in pigs, MAP3K8 expression was higher in mature CLs (or those of the mid-luteal phase) than in regressing CLs (late luteal phase). Further functional studies in cultured porcine luteal cells showed that P4 synthesis and the expression of genes encoding the key enzymes in P4 synthesis are significantly reduced when MAP3K8 is inhibited with the MAP3K8 inhibitor Tpl2 kinase inhibitor (MAP3K8i, 10μM). After 12–24h treatment of luteal cells with 100ngmL−1 LH, MAP3K8 expression and P4 secretion were significantly upregulated. In addition, the 10μM MAP3K8 inhibitor blocked the stimulatory effect of LH on P4 synthesis and extracellular signal-regulated kinase (ERK) 1/2 phosphorylation in porcine luteal cells. The LH-induced increases in MAP3K8 phosphorylation and expression, ERK1/2 phosphorylation and P4 synthesis were all blocked when protein kinase A was inhibited by its inhibitor H89 (20 μM) in porcine luteal cells. In conclusion, MAP3K8 mediates the LH-induced stimulation of P4 synthesis through the PKA/mitogen-activated protein kinase signalling pathway in porcine CL.

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