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Functional consequences of prolactin signalling in endothelial cells: a potential link with angiogenesis in pathophysiology?

Reuwer AQ, Nowak-Sliwinska P, Mans LA, van der Loos CM, von der Thüsen JH, Twickler MT, Spek CA, Goffin V, Griffioen AW, Borensztajn KS - J. Cell. Mol. Med. (2012)

Bottom Line: These effects are blocked by a specific prolactin receptor antagonist, del1-9-G129R-hPRL.Interestingly, while prolactin has only little effect on endothelial cell proliferation, it markedly stimulates endothelial cell migration.Again, migration was reverted by del1-9-G129R-hPRL, indicating a direct effect of prolactin on its receptor.

View Article: PubMed Central - PubMed

Affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands. a.q.reuwer@amc.uva.nl

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Related in: MedlinePlus

Effect of prolactin on in vivo angiogenesis in the CAM. Images show the CAM (EDD9) with or without treatment with prolactin (PRL) and prolactin with its receptor antagonist (PRL+Anta). The vasculature is visualized by FITC-dextran fluorescence angiography (25 mg/kg, 20 kD, λex= 470 nm). (A) Untreated CAM with small vessels and the capillary network. (B) Angiography of a CAM treated with prolactin (1 μg/embryo/day). (C) Angiography after treatment with prolactin (1 μg/embryo/day) mixed with its receptor antagonist (10 μg/embryo/day). Scale bar in (A) is valid for all three images. Arrows indicate the induced pillar formation and intussusceptive angiogenesis in the larger blood vessels. (D, E) Quantification of digital analysis of the angiography images. (D) Branching points/mm2 for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). (E) Number of segments/mm2 as a marker of vessel density for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). Mean values (± standard error of the mean) are shown for two different experiments, in which each condition was included four times (thus eight individual eggs). **P < 0.01.
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fig02: Effect of prolactin on in vivo angiogenesis in the CAM. Images show the CAM (EDD9) with or without treatment with prolactin (PRL) and prolactin with its receptor antagonist (PRL+Anta). The vasculature is visualized by FITC-dextran fluorescence angiography (25 mg/kg, 20 kD, λex= 470 nm). (A) Untreated CAM with small vessels and the capillary network. (B) Angiography of a CAM treated with prolactin (1 μg/embryo/day). (C) Angiography after treatment with prolactin (1 μg/embryo/day) mixed with its receptor antagonist (10 μg/embryo/day). Scale bar in (A) is valid for all three images. Arrows indicate the induced pillar formation and intussusceptive angiogenesis in the larger blood vessels. (D, E) Quantification of digital analysis of the angiography images. (D) Branching points/mm2 for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). (E) Number of segments/mm2 as a marker of vessel density for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). Mean values (± standard error of the mean) are shown for two different experiments, in which each condition was included four times (thus eight individual eggs). **P < 0.01.

Mentions: The angiogenic activity of prolactin was investigated in vivo using the early chicken embryo CAM assay. In control-treated embryos (0.9% NaCl), the capillary plexus was well developed and a homogeneous vascularization was observed (Fig. 2A). Topical administration of prolactin induced a clear change in the morphology of the vasculature (Fig. 2B). Digital analysis of the images did not reveal a change in the number of branching points: 1987(±58.87)/mm2 in the control condition versus 2124(±190.1)/mm2, P= 0.39, after addition of 1 μg prolactin and 2088(±85.71)/mm2, P= 0.34, after addition of 10 μg prolactin (Fig. 2D). By contrast, 10 μg prolactin induced a clear increase in vessel density compared to control [3683(±142.4)/mm2versus 3337(±36.5)/mm2, respectively, P= 0.0065; Fig. 2E], whilst addition of 1 μg prolactin had no effect on vessel density [3549(±340.2)/mm2, P= 0.42]. Combination of 1 μg prolactin with 10 μg of the prolactin receptor antagonist did not significantly affect the number of branching points [1885±(252.3)/mm2, P= 0.37; Fig. 2D] in comparison to the control condition. Additionally, prolactin plus antagonist did not influence the number of segments [3314±(398.0)/mm2, P= 0.85; Fig. 2E]. Moreover, prolactin enhanced the tortuosity of the vessels (Fig. 2B). The exposure to prolactin induced pillar formation and intussusceptive angiogenesis in the larger blood vessels (arrows in Fig. 2B), phenomena that are known to occur after exposure to the angiogenic growth factor VEGF [46, 47]. These effects of prolactin were markedly diminished by addition of the prolactin receptor antagonist del1-9-G129R-hPRL (Fig. 2C).


Functional consequences of prolactin signalling in endothelial cells: a potential link with angiogenesis in pathophysiology?

Reuwer AQ, Nowak-Sliwinska P, Mans LA, van der Loos CM, von der Thüsen JH, Twickler MT, Spek CA, Goffin V, Griffioen AW, Borensztajn KS - J. Cell. Mol. Med. (2012)

Effect of prolactin on in vivo angiogenesis in the CAM. Images show the CAM (EDD9) with or without treatment with prolactin (PRL) and prolactin with its receptor antagonist (PRL+Anta). The vasculature is visualized by FITC-dextran fluorescence angiography (25 mg/kg, 20 kD, λex= 470 nm). (A) Untreated CAM with small vessels and the capillary network. (B) Angiography of a CAM treated with prolactin (1 μg/embryo/day). (C) Angiography after treatment with prolactin (1 μg/embryo/day) mixed with its receptor antagonist (10 μg/embryo/day). Scale bar in (A) is valid for all three images. Arrows indicate the induced pillar formation and intussusceptive angiogenesis in the larger blood vessels. (D, E) Quantification of digital analysis of the angiography images. (D) Branching points/mm2 for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). (E) Number of segments/mm2 as a marker of vessel density for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). Mean values (± standard error of the mean) are shown for two different experiments, in which each condition was included four times (thus eight individual eggs). **P < 0.01.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3822974&req=5

fig02: Effect of prolactin on in vivo angiogenesis in the CAM. Images show the CAM (EDD9) with or without treatment with prolactin (PRL) and prolactin with its receptor antagonist (PRL+Anta). The vasculature is visualized by FITC-dextran fluorescence angiography (25 mg/kg, 20 kD, λex= 470 nm). (A) Untreated CAM with small vessels and the capillary network. (B) Angiography of a CAM treated with prolactin (1 μg/embryo/day). (C) Angiography after treatment with prolactin (1 μg/embryo/day) mixed with its receptor antagonist (10 μg/embryo/day). Scale bar in (A) is valid for all three images. Arrows indicate the induced pillar formation and intussusceptive angiogenesis in the larger blood vessels. (D, E) Quantification of digital analysis of the angiography images. (D) Branching points/mm2 for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). (E) Number of segments/mm2 as a marker of vessel density for CAM, stimulated with 0.9% NaCl alone (control, white bar) or 0.9% NaCl supplemented with the indicated amounts of prolactin (PRL, black bars) or prolactin with antagonist (PRL + Anta, grey bar). Mean values (± standard error of the mean) are shown for two different experiments, in which each condition was included four times (thus eight individual eggs). **P < 0.01.
Mentions: The angiogenic activity of prolactin was investigated in vivo using the early chicken embryo CAM assay. In control-treated embryos (0.9% NaCl), the capillary plexus was well developed and a homogeneous vascularization was observed (Fig. 2A). Topical administration of prolactin induced a clear change in the morphology of the vasculature (Fig. 2B). Digital analysis of the images did not reveal a change in the number of branching points: 1987(±58.87)/mm2 in the control condition versus 2124(±190.1)/mm2, P= 0.39, after addition of 1 μg prolactin and 2088(±85.71)/mm2, P= 0.34, after addition of 10 μg prolactin (Fig. 2D). By contrast, 10 μg prolactin induced a clear increase in vessel density compared to control [3683(±142.4)/mm2versus 3337(±36.5)/mm2, respectively, P= 0.0065; Fig. 2E], whilst addition of 1 μg prolactin had no effect on vessel density [3549(±340.2)/mm2, P= 0.42]. Combination of 1 μg prolactin with 10 μg of the prolactin receptor antagonist did not significantly affect the number of branching points [1885±(252.3)/mm2, P= 0.37; Fig. 2D] in comparison to the control condition. Additionally, prolactin plus antagonist did not influence the number of segments [3314±(398.0)/mm2, P= 0.85; Fig. 2E]. Moreover, prolactin enhanced the tortuosity of the vessels (Fig. 2B). The exposure to prolactin induced pillar formation and intussusceptive angiogenesis in the larger blood vessels (arrows in Fig. 2B), phenomena that are known to occur after exposure to the angiogenic growth factor VEGF [46, 47]. These effects of prolactin were markedly diminished by addition of the prolactin receptor antagonist del1-9-G129R-hPRL (Fig. 2C).

Bottom Line: These effects are blocked by a specific prolactin receptor antagonist, del1-9-G129R-hPRL.Interestingly, while prolactin has only little effect on endothelial cell proliferation, it markedly stimulates endothelial cell migration.Again, migration was reverted by del1-9-G129R-hPRL, indicating a direct effect of prolactin on its receptor.

View Article: PubMed Central - PubMed

Affiliation: Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands. a.q.reuwer@amc.uva.nl

Show MeSH
Related in: MedlinePlus