Effects of local growth factors on the secretory function of bovine corpus luteum during the oestrous cycle and pregnancy in vitro

Liebermann, Jürgen; Schams, D.; Miyamoto, Akio

doi:10.1071/rd9961003

Cited by 43 publications

(34 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These findings indicate that the response of the cells to hypoxia changes from the early to mid luteal stage, and suggest that early luteal cells are more resistant to the hypoxia-induced P4 decrease than mid luteal cells. It has also been suggested that early luteal cells maintain the ability for P4 production by luteotropic factors highly produced by them, such as prostaglandins (PGs) [32][33][34][35][36] and IGF-1 [37]. In general, injection of cows with PGF2α at the early luteal stage (within 5 days after ovulation) does not induce luteolysis, whereas injection 6 days after ovulation induces luteolysis [38,39].…”

Section: Discussionmentioning

confidence: 99%

Hypoxia is Important for Establishing Vascularization During Corpus Luteum Formation in Cattle

2010

View full text Add to dashboard Cite

Abstract. Hypoxia-inducible factor 1 (HIF1) has been demonstrated to have critical roles in angiogenesis via transcriptional regulation of angiogenic factors, such as vascular endothelial growth factor (VEGF). In the ovary, angiogenesis is known to occur after ovulation in the developing corpus luteum (CL) in mammals. To determine whether HIF1 participates in angiogenesis in bovine CL, the present study investigated the mRNA and protein expressions of the HIF1 alpha subunit (HIF1A) and VEGF in bovine CL during the estrous cycle. The effects of hypoxia on the expressions of HIF1A protein, VEGF mRNA and VEGF protein in bovine luteal cells were also examined by using a cell culture system. HIF1A mRNA expression was less at the regressed stage than at the other stages, whereas protein expression of HIF1A was highest at the early luteal stage and decreased thereafter. VEGF mRNA expression was highest at the developing luteal stage and decreased thereafter. VEGF protein expression was highest at the early luteal stage and decreased significantly at the regressed luteal stage. Hypoxia increased the amounts of HIF1A protein, VEGF mRNA and VEGF protein in cultured bovine luteal cells. Furthermore, we found that hypoxia inhibited progesterone production in the mid luteal cells, but not in the early luteal cells. The overall findings indicate that HIF1 is one of the factors promoting VEGF-induced angiogenesis during luteal development, and suggest that the hypoxic conditions formed after follicle rupture contribute to establishing luteal vascularization in cattle. Key words: Cattle, Corpus luteum, Hypoxia, Hypoxia-inducible factor 1, Vascular endothelial growth factor (J. Reprod. Dev. 56: [110][111][112][113][114][115][116] 2010) he corpus luteum (CL) is an organ that is temporarily formed and regressed during the female reproductive cycle. It is formed from a ruptured follicle after ovulation with rapid angiogenesis [1][2][3]. Angiogenesis is known to be stimulated by a variety of growth factors [1,2,4], one of the strongest which is vascular endothelial growth factor (VEGF) [5]. VEGF also has a role in the angiogenesis of newly formed CL in cattle [6,7]. Another factor, hypoxia-inducible factor 1 (HIF1), is a strong inducer of the transcription of erythropoietin [8] and VEGF [9]. A ruptured follicle just after ovulation is thought to be under hypoxic conditions because of bleeding and because it has an immature vasculature [10]. Therefore, we hypothesized that hypoxic conditions are important for establishing the vascular system during luteal development.HIF1 is an obligatory heterodimeric protein composed of two members of the basic-helix-loop-helix (bHLH)-containing PER-ARNT-SIM (PAS) domain family, HIF1A and the aryl hydrocarbon receptor nuclear translocator (ARNT) [11]. ARNT expression is not affected by oxygen concentration, whereas HIF1A is rapidly ubiquitinated under hypoxia, which targets the protein for degradation by the proteasome [12][13][14]. In bovine CL, HIF1 expression has been reported only in culture...

show abstract

Section: Discussionmentioning

confidence: 99%

Hypoxia is Important for Establishing Vascularization During Corpus Luteum Formation in Cattle

2010

View full text Add to dashboard Cite

show abstract

“…In vitro data by a novel microdialysis system (intact luteal tissue) demonstrate distinct and stage-specific effects of IGF-1 and IGF-2 on progesterone and oxytocin secretion with long lasting effects even after stop of the perfusion, especially during the late luteal phase and early pregnancy [30,64]. Since the proteins for IGF-1 [33] and IGFR-1 are mainly localized in large luteal cells, the regulation seems at least in part autocrine.…”

Section: Igf In Bovine Corpus Luteummentioning

confidence: 99%

Angiogenic Factors (VEGF, FGF and IGF) in the Bovine Corpus Luteum.

Schams

Berisha

2002

Journal of Reproduction and Development

View full text Add to dashboard Cite

Abstract. Angiogenesis, the development of the new capillaries by endothelial cell proliferation and outgrowth from pre-existing vessels, is one of the prominent features of early corpus luteum (CL). The process of angiogenesis is an important component of normal development and function of CL. Of the numerous promoters of angiogenesis and maintenance of new established capillaries that have been identified, the most important factors appear to be vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF). The biological effects of VEGF and FGF factor families are mediated by signaling through specific tyrosine kinase receptors. The VEGF, FGF and IGF family members in bovine CL are discussed with the literature available for large domestic animals. The highest expression for VEGF, VEGFR-2, FGF-2, FGFR, IGF-1, IGF-2 and IGFR1 were found during the early luteal phase (Ld 1-4) followed by a significant decrease afterwards. The VEGF and IGF-1 protein was localized predominantly in luteal cells. FGF-1 mRNA expression peaked (P<0.05) during mid-luteal stage and FGF-1 protein was localized in cytoplasm of luteal cells, but endothelial cells are always negative. FGF-2 protein during angiogenesis (d 1-5) was found in cytoplasm of endothelial cells and changed thereafter exclusively to the cytoplasm of luteal cells. In contrast, the IGF-2 protein is exclusively localized in pericytes and few endothelial cells. The results obtained (mainly in ruminant) suggest an important role of these growth factors for angiogenesis and furthermore for maintenance and function of the bovine corpus luteum.

show abstract

“…FGF2 is mitogenic for CL-derived endothelial cells (Gospodarowicz et al 1986) and luteal cells in culture (Grazul-Bilska et al 1995), and stimulated progesterone secretion when infused into bovine corpora lutea (Liebermann et al 1996). In the cow, FGF2 protein was specifically localised to endothelial cells and pericytes of the theca layer prior to the LH surge, but afterwards and in the collapsed follicle, FGF2 protein was found predominantly in the luteinising granulosa cell layer (Berisha et al 2006).…”

Section: Introductionmentioning

confidence: 99%

FGF2 is crucial for the development of bovine luteal endothelial networks in vitro

Woad¹,

Hammond²,

Mann³

et al. 2009

Reproduction

View full text Add to dashboard Cite

The development of the corpus luteum requires angiogenesis, and involves the complex interplay between factors such as vascular endothelial growth factor A (VEGFA), fibroblast growth factor 2 (FGF2) and platelet-derived growth factor (PDGF). However, the relative role of these factors remains to be elucidated. This study used a new physiologically relevant mixed luteal cell culture system to test the hypotheses that: a) FGF2 and VEGFA are critical for bovine luteal angiogenesis; and b) local luteal PDGF signalling stimulates the formation of endothelial networks. Cells were treated with receptor tyrosine kinase inhibitors against VEGFA (SU1498), FGF2 (SU5402) or PDGF (AG1295) activity. After 9 days in culture, endothelial cells were immunostained for von Willebrand factor (VWF) and quantified by image analysis. Highly organised intricate endothelial networks were formed in the presence of exogenous VEGFA and FGF2. The inhibition of FGF2 activity reduced the total area of VWF staining versus controls (O95%; P!0.001). Inhibition of VEGF and PDGF activity reduced the endothelial network formation by more than 60 and 75% respectively (P!0.05). Progesterone production increased in all treatments from day 1 to 7 (P!0.001), and was unaffected by FGF2 or PDGF receptor kinase inhibition (PO0.05), but was reduced by the VEGF receptor inhibitor on days 5 and 7 (P!0.001). In conclusion, this study confirmed that VEGF signalling regulates both bovine luteal angiogenesis and progesterone production. However, FGF2 was crucial for luteal endothelial network formation. Also, for the first time, this study showed that local luteal PDGF activity regulates bovine luteal endothelial network formation in vitro.

show abstract

Effects of local growth factors on the secretory function of bovine corpus luteum during the oestrous cycle and pregnancy in vitro

Cited by 43 publications

References 0 publications

Hypoxia is Important for Establishing Vascularization During Corpus Luteum Formation in Cattle

Hypoxia is Important for Establishing Vascularization During Corpus Luteum Formation in Cattle

Angiogenic Factors (VEGF, FGF and IGF) in the Bovine Corpus Luteum.

FGF2 is crucial for the development of bovine luteal endothelial networks in vitro

Contact Info

Product

Resources

About