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

1996 ◽  
Vol 8 (6) ◽  
pp. 1003 ◽  
Author(s):  
J Liebermann ◽  
D Schams ◽  
A Miyamoto

The impact of insulin-like growth factor-I (IGF-I) basic fibroblast growth factor (bFGF), endothelin-1 (ET-1), tumour necrosis factor-alpha (TNF-alpha), transforming growth factor-alpha (TGF-alpha) and platelet-derived growth factor (PDGF) on the release of progesterone (P4) and oxytocin (OT) from individual bovine corpora lutea at different stages of the oestrous cycle and pregnancy was evaluated with a microdialysis system (MDS) in vitro. IGF-I (1 microgram mL-1) induced significantly the acute effects on P4 release at the late luteal stage (Days 15-18) and early pregnancy (Days 60-120), whereas bFGF (100 ng mL-1) was extremely effective in stimulating P4 release particularly during the mid-luteal stage (Days 8-12). Both peptides stimulated (P < 0.05) the release of OT throughout the three luteal stages and during early and late pregnancy (Days 30-60 and Days 150-210). ET-1 (100 ng mL-1) clearly inhibited P4 release during the early (Days 5-7) and mid-luteal phase and stimulated OT release only during the mid-luteal stage (P < 0.001). TNF-alpha (100 ng mL-1) stimulated the release of P4 exclusively at the early luteal phase (P < 0.05), whereas OT secretion was increased by TNF-alpha during all stages of the oestrous cycle (P < 0.001). TGF-alpha and PDGF (100 ng mL-1) were effective in stimulating P4 release particularly during late pregnancy (P < 0.05). In contrast, stimulation of OT secretion by TGF-alpha was maximal during the late-luteal stage (P < 0.001), whereas PDGF significantly increased OT secretion during the oestrous cycle (except the early luteal stage) and pregnancy (P < 0.001). The data demonstrate distinct and stage-specific effects of growth factors on P4 and OT secretion in vitro. IGF-I, bFGF and TGF-alpha may play an important role in corpus luteum (CL) function during the oestrous cycle and pregnancy since they are locally expressed and synthesized, there are receptors for these growth factors, and they have been demonstrated to exert biological effects on the CL.

Reproduction ◽  
2000 ◽  
pp. 293-302 ◽  
Author(s):  
KJ Woad ◽  
G Baxter ◽  
CO Hogg ◽  
TA Bramley ◽  
R Webb ◽  
...  

Previous studies have implicated insulin-like growth factors I and II (IGF-I and -II), in the regulation of ovarian function. The present study investigated the localization of mRNA encoding IGF-I and -II and the type 1 IGF receptor using in situ hybridization to determine further the roles of the IGFs within the bovine corpus luteum at precise stages of the oestrous cycle. Luteal expression of mRNA encoding IGF-I and -II and the type 1 IGF receptor was detected throughout the oestrous cycle. The expression of IGF-I mRNAvaried significantly during the oestrous cycle. IGF-I mRNA concentrations were significantly higher on day 15 than on day 10, and IGF-I mRNA in the regressing corpus luteum at 48 h after administration of exogenous prostaglandin was significantly greater than in the early or mid-luteal phase (days 5 and 10). In contrast, there was no significant effect of day of the oestrous cycle on expression of mRNA for IGF-II and the type 1 IGF receptor in the corpus luteum. Expression of IGF-II mRNA was localized to a subset of steroidogenic luteal cells and was also associated with cells of the luteal vasculature. mRNA encoding the type 1 IGF receptor was widely expressed in a pattern indicative of expression in large and small luteal cells. These data demonstrate that the bovine corpus luteum is a site of IGF production and reception throughout the luteal phase. Furthermore, this study highlights the potential of IGF-II in addition to IGF-I in the autocrine and paracrine regulation of luteal function.


1994 ◽  
Vol 267 (6) ◽  
pp. E990-E1001 ◽  
Author(s):  
M. Slater ◽  
J. Patava ◽  
K. Kingham ◽  
R. S. Mason

Human fetal osteoblast-like cells formed a regular multilayered structure in vitro with an extensive collagen-based extracellular matrix. With colloidal gold immunocytochemistry, labels for alkaline phosphatase and osteocalcin were distributed in a relatively diffuse pattern, in contrast to the bone growth factors, insulin-like growth factors I and II (IGF-I and IGF-II), transforming growth factor-beta 1 (TGF-beta 1), and basic fibroblast growth factor, which were colocalized in the collagenous matrix of the multilayer. The inclusion of 17 beta-estradiol (10(-11) to 10(-9) M) in the culture medium increased multilayer depths, increased labeling for IGF-I, IGF-II, and TGF-beta 1, and resulted in earlier detection of TGF-beta 1 label. In contrast, the increase in multilayer depth resulting from treatment with human platelets, an exogenous source of growth factors, was not accompanied by an increase in matrix IGF-I, IGF-II, or TGF-beta 1 label, suggesting a particular effect of estradiol to facilitate this process. Because growth factors in bone matrix may act as coupling agents when released during resorption, reduced growth factor incorporation in the presence of reduced sex steroid concentrations may lead to uncoupling of resorption and subsequent formation.


Reproduction ◽  
2002 ◽  
pp. 135-142 ◽  
Author(s):  
M Sakaguchi ◽  
T Dominko ◽  
N Yamauchi ◽  
ML Leibfried-Rutledge ◽  
T Nagai ◽  
...  

The mechanism for the accelerating effects of epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) on the meiotic cell cycle of bovine oocytes cultured in vitro was investigated. Cumulus-oocyte complexes (COCs) were obtained from small (< or = 3 mm in diameter), medium (4-6 mm in diameter) or large (7-10 mm in diameter) ovarian follicles and cultured with or without a combination of EGF and IGF-I (growth factors). Growth factors significantly increased the frequency of first polar body extrusion of oocytes derived from small follicles at 16 h of culture (PB16 oocytes; with growth factors: 75%; without growth factors: 55%), but did not increase the frequency in oocytes from medium or large follicles. COCs from small follicles were cultured with individual growth factors and sampled for kinase activity. The frequencies of polar body extrusion in EGF only (67%) and EGF + IGF-I (75%) treatment groups were significantly higher than those in the control (no growth factor) group (49%), but not significantly higher than in the IGF-I only group (63%). The H1 kinase activity at 6-8 h of culture in each group increased significantly from the baseline value at 0 h of culture, and the H1 kinase activities in the EGF only, IGF-I only and EGF + IGF-I treatment groups were significantly higher than those in the control group at 8 h of culture. MAP kinase activity was significantly higher than the baseline value and significantly higher than that in the control group at 6 h of culture in the EGF treatment group only. In conclusion, EGF and IGF-I act on COCs from small follicles to accelerate the meiotic cell cycle of the oocytes. This accelerating effect may be related to increased H1 and MAP kinase activities during the early stages of maturation.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Jason Zell ◽  
Jeremy Montague ◽  
Tomas Lopez ◽  
Mudd Laura

Ethanol ingestion by pregnant women is the primary cause of fetal alcohol syndrome, which is characterized by brain abnormalities and decreased mental capacity. In the present study,cultured neurons from embryonic rat cortices were used to study the effects of ethanol on cell survival and the potential for neuroprotection by certain growth factors and estrogen. Neurons were grown in the presence of a glial plane and in the absence of serum. Survival was assessed following chronic treatment with ethanol (45 mM) in the presence and absence of either nerve growth factor (NGF, 100ng/ml), basic fibroblast growth factor (bFGF, 5ng/ml), insulin-like growth factor I or II (IGF-I, IGF-II, both 10ng/ml), or estrogen (Es, 10nM) added on days one and four in vitro. On day in vitro 4 (DIV4) ethanol effects on neuronal viability were significantly prevented by NGF, bFGF, IGF-I, and Es. DIV6 survival of ethanol-treated neurons was increased significantly by treatment with NGF, bFGF, IGF-I, IGF-II, and Es. Nerve growth factor, bFGF, and IGF-I effects were shown to be dose-dependent. Administration of 1-100 ng/ml NGF, 0.05-5 ng/ml bFGF and 0.1-10ng/ml IGF-I led to statistically significant effects at 10, 5, and 1 ng/ml, respectively. Thus, ethanol’s effect on neuronal survival may be inhibited by simultaneous treatment with physiological doses of these factors.


Reproduction ◽  
2001 ◽  
pp. 865-873 ◽  
Author(s):  
G Iniguez ◽  
A Villavicencio ◽  
F Gabler ◽  
A Palomino ◽  
M Vega

The presence of insulin-like growth factors (IGF), IGF binding proteins (IGFBP) and IGF receptor type 1 (IGF-IR) in the human corpus luteum was investigated by examining the expression and production of related proteins throughout the lifespan of the corpus luteum and the action of nitric oxide upon their production. The expression of proteins in corpora lutea from the early, mid-and late luteal phases was assessed by immunohisto-chemistry, evaluated by a semi-quantitative analysis and the functional study was performed in corpus luteum explants incubated with nitric oxide donors. IGF-I and -II and IGFBP-1 and -3 were measured in the culture media by specific immunoassays. The results showed that IGF-I and -II, IGFBP-1 to -6 and IGF-IR were detected in the human corpus luteum throughout the luteal phase. Moreover, the expression and production of IGF-I and IGFBP-1 increased progressively from corpora lutea from the early to late luteal phases (P < 0.05), whereas the expression and production of IGFBP-2, -4 and -5 were significantly higher in corpora lutea from the mid-luteal phase (P < 0.05). No differences were observed in the expression of IGF-II, IGFBP-3 and -6 and IGF-IR throughout the lifespan of the corpus luteum. However, functional studies showed that nitric oxide donors elicited a stimulatory action on production of IGF-I in corpora lutea from the early luteal phase (80%) and on production of IGFBP-1 in corpora lutea from the late luteal phase (50%) (P < 0.05), whereas production of IGF-II and IGFBP-3 was not affected by nitric oxide. In conclusion, the components of the IGF-IGFBP system are expressed in the human corpus luteum throughout its lifespan. Nitric oxide regulates IGF-I and IGFBP-1 production, indicating that the growth factors may serve, at least in part, as mediators of the action of nitric oxide in the human corpus luteum.


1997 ◽  
Vol 3 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Henry de F Webster

Insulin-like growth factor-I (IGF-I), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF) and ciliary neurotrophic factor (CNTF) are multifunctional growth factors which are found in the CNS. Oligodendroglia are the cells that form and maintain myelin sheaths and many in vitro experiments have shown that these growth factors promote the proliferation, differentiation and survival of cells in the oligodendroglial lineage. Since myelin breakdown is often severe in multiple sclerosis (MS), the possibility of growth factor use in the treatment of MS has been considered and recently, IGF-I treatment has been shown to reduce lesion severity and promote myelin regeneration in experimental autoimmune encephalomyelitis (EAE), an animal model of MS. This review briefly summarizes the structural characteristics of these growth factors and the actions which might help reduce oligodendrocyte-myelin sheath injury in MS and promote myelin regeneration.


Reproduction ◽  
2000 ◽  
pp. 109-114 ◽  
Author(s):  
Z Ge ◽  
WE Nicholson ◽  
DM Plotner ◽  
CE Farin ◽  
JE Gadsby

Insulin-like growth factor I (IGF-I) is believed to play a luteotrophic role in the pig corpus luteum during the oestrous cycle. Since the actions of IGF-I in target tissues are mediated by the type I IGF receptor, the concentrations of IGF-I receptor mRNA and protein were examined in pig corpora lutea at different stages of the oestrous cycle. Corpora lutea were collected from normally cyclic gilts on days 4, 7, 10, 13, 15 and 16 of the oestrous cycle (n = 4 animals per day). Corpora lutea on days 7, 10 and 13 were dissociated with collagenase, and large and small luteal cell sub-populations were separated by elutriation. Northern and slot blots were used to examine mRNA, and western blots were used to measure the concentrations of IGF-I receptor protein in the pig corpus luteum. On northern blots, luteal IGF-I receptor mRNA was present as a single 11 kb transcript. The slot blots showed that the steady state expression of IGF-I receptor mRNA increased significantly (P < 0.05) from its lowest value on day 4, to reach a maximum on days 13-16. IGF-I receptor mRNA was also expressed to a greater extent in large compared with small luteal cells (P < 0.05). On western blots, IGF-I receptor appeared as a 95 kDa protein band (beta-subunit) and IGF-I receptor protein concentrations were significantly higher (P < 0.05) on days 4-10 than on days 13-16. Finally, large luteal cells appeared to contain more IGF-I receptor protein than the small luteal cells. In conclusion, since IGF-I receptor was detected in the pig corpus luteum, it is a likely target tissue for IGF-I, especially during the early luteal phase. Furthermore, IGF-I receptor was localized primarily on large luteal cells, thus it is hypothesized that IGF-I may play a paracrine role in the pig corpus luteum.


1991 ◽  
Vol 3 (2) ◽  
pp. 201 ◽  
Author(s):  
U Michel ◽  
S Ludemann ◽  
H Jarry ◽  
W Wuttke

The effect of several growth factors, protein and steroid hormones on follicle stimulating hormone (FSH)-stimulated and basal inhibin secretion by mature porcine granulosa cells (g-cells) in culture was examined in order to elucidate the putative role of growth factors and hormones in the regulation of inhibin secretion by porcine g-cells in vitro. Cells were incubated with the respective hormones over a timespan of 0-144 h and immunoreactive inhibin was measured with a radioimmunoassay against porcine inhibin. Epidermal growth factor (EGF) and human transforming growth factor type beta (TGF-beta) decreased basal and gonadotrophin-stimulated inhibin and progesterone in a dose-dependent manner. In the absence of insulin, insulin-like growth factor type I (IGF-I) caused a 4-fold enhancement of basal inhibin secretion, but inhibin secretion was elevated only to 20% above control in the presence of 500 nM insulin. Porcine platelet-derived growth factor (PDGF) had no significant effect on basal or FSH-induced inhibin secretion by g-cells. In addition, neither gonadotrophin-releasing hormone (GnRH) nor prolactin (PRL), arginine vasopressin (AVP) and oxytocin affected basal or FSH-stimulated inhibin release by porcine g-cells. Oestradiol caused a slight but significant (P less than 0.01) rise of basal inhibin production (158% of control) in the last 2 days of culture (96-144 h) and the effect of androstenedione on basal (158% of control) and FSH-stimulated (140% of control) inhibin release (P less than 0.01) was also only visible on Days 4-6 of culture. In contrast to androstenedione and oestradiol, progesterone did not show any effect during 6 days of culture in a dose range of 10(-5) to 10(-9) M. Like steroids, prostaglandin E2 (PGE2) had a stimulatory effect on basal inhibin production (250% of control) by porcine g-cells, visible on Days 3-6 of culture, but an inhibitory effect on FSH-stimulated release (less than 40% of control). Over all the experiments with different hormones and growth factors, tested in varying doses and over a time span of 0-144 h, there was a strong correlation between progesterone and inhibin secretion by g-cells (0-48 h = 0.78; 48-96 h = 0.92; 96-144 h = 0.92). These results suggest that EGF, TGF-beta, IGF-I, oestradiol and androstendione as well as PGE2 have para- and/or autocrine modulatory effects on basal and FSH-stimulated inhibin secretion by mature porcine g-cells in vitro and further demonstrate that the secretion of the proteohormone inhibin and the steroid progesterone are closely related.


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