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Angiogenic, hyperpermeability and vasodilator network in utero-placental units along pregnancy in the guinea-pig (Cavia porcellus).

Valdés G, Erices R, Chacón C, Corthorn J - Reprod. Biol. Endocrinol. (2008)

Bottom Line: According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy.In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations.Western blots for eNOS and Flt-1 in placental homogenates showed no significant temporal differences along pregnancy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Departamento de Nefrología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, 8330024 Santiago, Chile. gvaldes@med.puc.cl

ABSTRACT

Background: The angiogenic and invasive properties of the cytotrophoblast are crucial to provide an adequate area for feto-maternal exchange. The present study aimed at identifying the localization of interrelated angiogenic, hyperpermeability and vasodilator factors in the feto-maternal interface in pregnant guinea-pigs.

Methods: Utero-placental units were collected from early to term pregnancy. VEGF, Flt-1, KDR, B2R and eNOS were analyzed by immunohistochemistry, and the intensity of the signals in placenta and syncytial streamers was digitally analysed. Flt1 and eNOS content of placental homogenates was determined by western blotting. Statistical analysis used one-way analysis of variance and Tukey's Multiple Comparison post-hoc test.

Results: In the subplacenta, placental interlobium and labyrinth VEGF, Flt-1, KDR, B2R and eNOS were expressed in all stages of pregnancy. Syncytial streamers in all stages of gestation, and cytotrophoblasts surrounding myometrial arteries in early and mid pregnancy - and replacing the smooth muscle at term - displayed immunoreactivity for VEGF, Flt-1, KDR, eNOS and B2R. In partly disrupted mesometrial arteries in late pregnancy cytotrophoblasts and endothelial cells expressed VEGF, Flt-1, KDR, B2R and eNOS. Sections incubated in absence of the first antibody, or in presence of rabbit IgG fraction and mouse IgG serum, yielded no staining. According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy. In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations. Western blots for eNOS and Flt-1 in placental homogenates showed no significant temporal differences along pregnancy.

Conclusion: The demonstration of different angiogenic, hyperpermeability and vasodilator factors in the same cellular protagonists of angiogenesis and invasion in the pregnant guinea-pig, supports the presence of a functional network, and strengthens the argument that this species provides an adequate model to understand human pregnancy.

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Control sections at different days of pregnancy of the subplacenta and syncytial streamers (A, D), interlobium (B, E) and mesometrial arteries (C, F), which yielded no immunoreactivity incubated with non-specific IgG from mouse (1:50) and rabbit (1:100), species in which the antibodies were raised. Mouse IgG serum in (A, B, C) and rabbit IgG fraction in (D, E, F). Bar = 100 μm
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Figure 9: Control sections at different days of pregnancy of the subplacenta and syncytial streamers (A, D), interlobium (B, E) and mesometrial arteries (C, F), which yielded no immunoreactivity incubated with non-specific IgG from mouse (1:50) and rabbit (1:100), species in which the antibodies were raised. Mouse IgG serum in (A, B, C) and rabbit IgG fraction in (D, E, F). Bar = 100 μm

Mentions: Mesometrial arteries in early (20 days) and mid (40 days) pregnancy had a thick multilayer of smooth muscle cells and no trophoblasts were observed in their periphery or within the muscle layer. At term pregnancy (60 days) cytotrophoblasts replaced part of the muscle layer, and presented a positive signal for VEGF, Flt-1, KDR, B2R and eNOS. Swollen endothelial cells, identified by vWF, also expressed VEGF, Flt-1, KDR, B2R and eNOS (Figure 8). Control sections incubated with rabbit and mouse non-specific immunoglobulin (Figure 9), or in absence of the first antibody (not shown), yielded no staining in different structures and stages of pregnancy.


Angiogenic, hyperpermeability and vasodilator network in utero-placental units along pregnancy in the guinea-pig (Cavia porcellus).

Valdés G, Erices R, Chacón C, Corthorn J - Reprod. Biol. Endocrinol. (2008)

Control sections at different days of pregnancy of the subplacenta and syncytial streamers (A, D), interlobium (B, E) and mesometrial arteries (C, F), which yielded no immunoreactivity incubated with non-specific IgG from mouse (1:50) and rabbit (1:100), species in which the antibodies were raised. Mouse IgG serum in (A, B, C) and rabbit IgG fraction in (D, E, F). Bar = 100 μm
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2291058&req=5

Figure 9: Control sections at different days of pregnancy of the subplacenta and syncytial streamers (A, D), interlobium (B, E) and mesometrial arteries (C, F), which yielded no immunoreactivity incubated with non-specific IgG from mouse (1:50) and rabbit (1:100), species in which the antibodies were raised. Mouse IgG serum in (A, B, C) and rabbit IgG fraction in (D, E, F). Bar = 100 μm
Mentions: Mesometrial arteries in early (20 days) and mid (40 days) pregnancy had a thick multilayer of smooth muscle cells and no trophoblasts were observed in their periphery or within the muscle layer. At term pregnancy (60 days) cytotrophoblasts replaced part of the muscle layer, and presented a positive signal for VEGF, Flt-1, KDR, B2R and eNOS. Swollen endothelial cells, identified by vWF, also expressed VEGF, Flt-1, KDR, B2R and eNOS (Figure 8). Control sections incubated with rabbit and mouse non-specific immunoglobulin (Figure 9), or in absence of the first antibody (not shown), yielded no staining in different structures and stages of pregnancy.

Bottom Line: According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy.In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations.Western blots for eNOS and Flt-1 in placental homogenates showed no significant temporal differences along pregnancy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Departamento de Nefrología, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, 8330024 Santiago, Chile. gvaldes@med.puc.cl

ABSTRACT

Background: The angiogenic and invasive properties of the cytotrophoblast are crucial to provide an adequate area for feto-maternal exchange. The present study aimed at identifying the localization of interrelated angiogenic, hyperpermeability and vasodilator factors in the feto-maternal interface in pregnant guinea-pigs.

Methods: Utero-placental units were collected from early to term pregnancy. VEGF, Flt-1, KDR, B2R and eNOS were analyzed by immunohistochemistry, and the intensity of the signals in placenta and syncytial streamers was digitally analysed. Flt1 and eNOS content of placental homogenates was determined by western blotting. Statistical analysis used one-way analysis of variance and Tukey's Multiple Comparison post-hoc test.

Results: In the subplacenta, placental interlobium and labyrinth VEGF, Flt-1, KDR, B2R and eNOS were expressed in all stages of pregnancy. Syncytial streamers in all stages of gestation, and cytotrophoblasts surrounding myometrial arteries in early and mid pregnancy - and replacing the smooth muscle at term - displayed immunoreactivity for VEGF, Flt-1, KDR, eNOS and B2R. In partly disrupted mesometrial arteries in late pregnancy cytotrophoblasts and endothelial cells expressed VEGF, Flt-1, KDR, B2R and eNOS. Sections incubated in absence of the first antibody, or in presence of rabbit IgG fraction and mouse IgG serum, yielded no staining. According to the digital analysis, Flt-1 increased in the placental interlobium in days 40 and 60 as compared to day 20 (P = 0.016), and in the labyrinth in day 60 as compared to days 20 and 40 (P = 0.026), while the signals for VEGF, KDR, B2R, and eNOS showed no variations along pregnancy. In syncytial streamers the intensity of VEGF immunoreactivity was increased in day 40 in comparison to day 20 (P = 0.027), while that of B2R decreased in days 40 and 60 as compared to day 20 (P = 0.011); VEGF, Flt-1, KDR, B2R and eNOS expression showed no variations. Western blots for eNOS and Flt-1 in placental homogenates showed no significant temporal differences along pregnancy.

Conclusion: The demonstration of different angiogenic, hyperpermeability and vasodilator factors in the same cellular protagonists of angiogenesis and invasion in the pregnant guinea-pig, supports the presence of a functional network, and strengthens the argument that this species provides an adequate model to understand human pregnancy.

Show MeSH
Related in: MedlinePlus