Mixed origin of neovascularization of human endometrial grafts in immunodeficient mouse models.
BACKGROUND
In vivo mouse models have been developed to study the physiology of normal and pathologic endometrium. Although angiogenesis is known to play an important role in endometrial physiology and pathology, the origin of neovasculature in xenografts remains controversial. The aim of this study was to assess the origin of the neovasculature of endometrial grafts in different mouse models.


METHODS
Human proliferative endometrium (n = 19 women) was grafted s.c. in two immunodeficient mouse strains: nude (n = 8) and severely compromised immunodeficient (SCID; n = 20). Mice were also treated with estradiol, progesterone or levonorgestrel. Fluorescence in-situ hybridization using a centromeric human chromosome X probe, immunohistochemistry (von Willebrand factor and collagen IV) and lectin perfusion were performed to identify the origin of the vessels.


RESULTS
More than 90% of vessels within xenografts were of human origin 4 weeks after implantation. Some vessels (9.67 +/- 2.01%) were successively stained by human or mouse specific markers, suggesting the presence of chimeric vessels exhibiting a succession of human and murine portions. No difference in staining was observed between the two strains of mouse or different hormone treatments. Furthermore, erythrocytes were found inside human vessels, confirming their functionality.


CONCLUSIONS
This article shows that human endometrial grafts retain their own vessels, which connect to the murine vasculature coming from the host tissue and become functional.
Alvarez Gonzalez
M-L
ML
Laboratory of Tumor and Development Biology, GIGA-Research, University de Liège, Tour de Pathologie (B23), Sart-Tilman, B-4000 Liège, Belgium.
Frankenne
F
F
Galant
C
C
Marbaix
E
E
Foidart
J-M
JM
Nisolle
M
M
Béliard
A
A
D000818:Animals; D002678:Chimera; D004717:Endometrium / Q000098:blood supply* / Q000637:transplantation*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008819:Mice, Nude; D016513:Mice, SCID; D009389:Neovascularization, Pathologic / Q000473:pathology*; D018919:Neovascularization, Physiologic / Q000502:physiology*; D014183:Transplantation, Heterologous