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Conditional ablation of macrophages disrupts ovarian vasculature.

Turner EC, Hughes J, Wilson H, Clay M, Mylonas KJ, Kipari T, Duncan WC, Fraser HM - Reproduction (2011)

Bottom Line: As macrophage ablation progressed, increasing amounts of ovarian haemorrhage were observed affecting both luteal and thecal tissue associated with significant endothelial cell depletion, increased erythrocyte accumulation and increased follicular atresia by 16  h.These events were followed by necrosis and profound structural damage.These results show that macrophages play a critical role in maintaining ovarian vascular integrity.

View Article: PubMed Central - PubMed

Affiliation: MRC Human Reproductive Sciences Unit, Queen's Institute of Medical Research, Centre for Reproductive Biology Obstetrics and Gynaecology, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.

ABSTRACT
Macrophages are the most abundant immune cell within the ovary. Their dynamic distribution throughout the ovarian cycle and heterogenic array of functions suggest the involvement in various ovarian processes, but their functional role has yet to be fully established. The aim was to induce conditional macrophage ablation to elucidate the putative role of macrophages in maintaining the integrity of ovarian vasculature. Using the CD11b-diphtheria toxin receptor (DTR) mouse, in which expression of human DTR is under the control of the macrophage-specific promoter sequence CD11b, ovarian macrophages were specifically ablated in adult females by injections of diphtheria toxin (DT). CD11b-DTR mice were given DT treatment or vehicle and ovaries collected at 2, 8, 16, 24 and 48  h. Histochemical stains were employed to characterise morphological changes, immunohistochemistry for F4/80 to identify macrophages and the endothelial cell marker CD31 used to quantify vascular changes. In normal ovaries, macrophages were detected in corpora lutea and in the theca layer of healthy and atretic follicles. As macrophage ablation progressed, increasing amounts of ovarian haemorrhage were observed affecting both luteal and thecal tissue associated with significant endothelial cell depletion, increased erythrocyte accumulation and increased follicular atresia by 16  h. These events were followed by necrosis and profound structural damage. Changes were limited to the ovary, as DT treatment does not disrupt the vasculature of other tissues likely reflecting the unique cyclical nature of the ovarian vasculature and heterogeneity between macrophages within different tissues. These results show that macrophages play a critical role in maintaining ovarian vascular integrity.

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Related in: MedlinePlus

Ovarian sections stained for macrophages by F4/80 showing (A) corpus luteum from control ovary showing healthy luteal cells and the presence of macrophages (brown-staining, black arrows), often associated with blood vessels and (B) a haemorrhagic area of a corpus luteum after 16 h treatment with the absence of F4/80-positive macrophages. (C) Antral follicle from control ovary showing macrophage staining in thecal layer (T) (brown-staining, black arrows). (D) Follicle from a treated animal at 16 h showing absence of macrophages. G, granulosa cell layer. Bar=20 μm.
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fig3: Ovarian sections stained for macrophages by F4/80 showing (A) corpus luteum from control ovary showing healthy luteal cells and the presence of macrophages (brown-staining, black arrows), often associated with blood vessels and (B) a haemorrhagic area of a corpus luteum after 16 h treatment with the absence of F4/80-positive macrophages. (C) Antral follicle from control ovary showing macrophage staining in thecal layer (T) (brown-staining, black arrows). (D) Follicle from a treated animal at 16 h showing absence of macrophages. G, granulosa cell layer. Bar=20 μm.

Mentions: Macrophages stained for F4/80 were observed at varying numbers within the corpora lutea of control ovaries and were often associated with the microvasculature (Fig. 3A). In treated animals, macrophages were absent within the areas of luteal haemorrhage and pyknosis by 16 h (Fig. 3B), although a few were detected in luteal areas which had retained morphologically normal luteal cells (LCs). This was not unexpected as the ablation of macrophages is not 100% in other solid organs (Duffield et al. 2005). Macrophages were also present in the thecal layer of developing follicles in control ovaries (Fig. 3C) but were absent by 16 h in treated mice where follicular integrity was lost and haemorrhage was evident (Fig. 3D).


Conditional ablation of macrophages disrupts ovarian vasculature.

Turner EC, Hughes J, Wilson H, Clay M, Mylonas KJ, Kipari T, Duncan WC, Fraser HM - Reproduction (2011)

Ovarian sections stained for macrophages by F4/80 showing (A) corpus luteum from control ovary showing healthy luteal cells and the presence of macrophages (brown-staining, black arrows), often associated with blood vessels and (B) a haemorrhagic area of a corpus luteum after 16 h treatment with the absence of F4/80-positive macrophages. (C) Antral follicle from control ovary showing macrophage staining in thecal layer (T) (brown-staining, black arrows). (D) Follicle from a treated animal at 16 h showing absence of macrophages. G, granulosa cell layer. Bar=20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3101494&req=5

fig3: Ovarian sections stained for macrophages by F4/80 showing (A) corpus luteum from control ovary showing healthy luteal cells and the presence of macrophages (brown-staining, black arrows), often associated with blood vessels and (B) a haemorrhagic area of a corpus luteum after 16 h treatment with the absence of F4/80-positive macrophages. (C) Antral follicle from control ovary showing macrophage staining in thecal layer (T) (brown-staining, black arrows). (D) Follicle from a treated animal at 16 h showing absence of macrophages. G, granulosa cell layer. Bar=20 μm.
Mentions: Macrophages stained for F4/80 were observed at varying numbers within the corpora lutea of control ovaries and were often associated with the microvasculature (Fig. 3A). In treated animals, macrophages were absent within the areas of luteal haemorrhage and pyknosis by 16 h (Fig. 3B), although a few were detected in luteal areas which had retained morphologically normal luteal cells (LCs). This was not unexpected as the ablation of macrophages is not 100% in other solid organs (Duffield et al. 2005). Macrophages were also present in the thecal layer of developing follicles in control ovaries (Fig. 3C) but were absent by 16 h in treated mice where follicular integrity was lost and haemorrhage was evident (Fig. 3D).

Bottom Line: As macrophage ablation progressed, increasing amounts of ovarian haemorrhage were observed affecting both luteal and thecal tissue associated with significant endothelial cell depletion, increased erythrocyte accumulation and increased follicular atresia by 16  h.These events were followed by necrosis and profound structural damage.These results show that macrophages play a critical role in maintaining ovarian vascular integrity.

View Article: PubMed Central - PubMed

Affiliation: MRC Human Reproductive Sciences Unit, Queen's Institute of Medical Research, Centre for Reproductive Biology Obstetrics and Gynaecology, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.

ABSTRACT
Macrophages are the most abundant immune cell within the ovary. Their dynamic distribution throughout the ovarian cycle and heterogenic array of functions suggest the involvement in various ovarian processes, but their functional role has yet to be fully established. The aim was to induce conditional macrophage ablation to elucidate the putative role of macrophages in maintaining the integrity of ovarian vasculature. Using the CD11b-diphtheria toxin receptor (DTR) mouse, in which expression of human DTR is under the control of the macrophage-specific promoter sequence CD11b, ovarian macrophages were specifically ablated in adult females by injections of diphtheria toxin (DT). CD11b-DTR mice were given DT treatment or vehicle and ovaries collected at 2, 8, 16, 24 and 48  h. Histochemical stains were employed to characterise morphological changes, immunohistochemistry for F4/80 to identify macrophages and the endothelial cell marker CD31 used to quantify vascular changes. In normal ovaries, macrophages were detected in corpora lutea and in the theca layer of healthy and atretic follicles. As macrophage ablation progressed, increasing amounts of ovarian haemorrhage were observed affecting both luteal and thecal tissue associated with significant endothelial cell depletion, increased erythrocyte accumulation and increased follicular atresia by 16  h. These events were followed by necrosis and profound structural damage. Changes were limited to the ovary, as DT treatment does not disrupt the vasculature of other tissues likely reflecting the unique cyclical nature of the ovarian vasculature and heterogeneity between macrophages within different tissues. These results show that macrophages play a critical role in maintaining ovarian vascular integrity.

Show MeSH
Related in: MedlinePlus