Macrophage migration inhibitory factor elicits an angiogenic phenotype in human ectopic endometrial cells and triggers the production of major angiogenic factors via CD44, CD74, and MAPK signaling pathways.
BACKGROUND
An active angiogenesis is required for ectopic endometrial tissue growth. Our previous studies led to the identification of macrophage migration inhibitory factor (MIF), which is markedly elevated in active, vascularized, and early-stage endometriotic lesions, as a potent mitogenic factor for endothelial cells.


OBJECTIVE
Our objective was to study the mechanisms by which MIF may stimulate angiogenesis in ectopic endometrial implantation sites.


METHODS
Primary cultures of ectopic endometrial cells were exposed to MIF, and the release of major angiogenic factors with targeted disruption of MIF signaling pathways was assessed.


METHODS
Patients were women found to have endometriosis during laparoscopy.


METHODS
The study was conducted at a hospital and reproduction research laboratory.


METHODS
Biopsies were removed from endometriotic lesions.


METHODS
Vascular endothelial cell growth factor (VEGF), IL-8, and monocyte chemotactic protein-1 (MCP-1) mRNA and protein levels and expression and small interfering RNA silencing of MIF CD74/CD44 receptor complex and phosphorylation of ERK and p38 MAPKs were evaluated.


RESULTS
MIF markedly up-regulated VEGF, IL-8, and MCP-1 expression in endometriotic cells. Such an effect was abolished by (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1), a specific inhibitor of MIF, and significantly down-regulated after specific small interfering RNA silencing of CD44 or CD74. MIF treatment strongly activated ERK and p38 MAPKs, and specific inhibitors of both pathways completely blocked basal and MIF-induced VEGF, IL-8, and MCP-1 synthesis.


CONCLUSIONS
These results show for the first time that MIF exerts a potent indirect angiogenic effect by interacting with ectopic endometrial cells and inducing the secretion of major angiogenic factors via CD44, CD74, and MAPK signaling pathways and provide evidence for a possible new mechanism underlying endometriosis development and pathophysiology.
Veillat
Véronique
V
Centre de recherche, Hôpital Saint-François d'Assise, and Faculty de Médecine, Université Laval, 10, rue de l'Espinay, Local D0-711, Québec (Québec), Canada G1L 3L5.
Carli
Cédric
C
Metz
Christine N
CN
Al-Abed
Yousef
Y
Naccache
Paul H
PH
Akoum
Ali
A
D043925:Angiogenesis Inducing Agents / Q000378:metabolism*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics*; D001706:Biopsy; D018932:Chemokine CCL2 / Q000235:genetics; D017931:DNA Primers; D004715:Endometriosis / Q000473:pathology; D004717:Endometrium / Q000166:cytology* / Q000187:drug effects; D005260:Female; D020868:Gene Silencing / Q000187:drug effects; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics*; D016209:Interleukin-8 / Q000235:genetics; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics* / Q000494:pharmacology* / Q000502:physiology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010641:Phenotype; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D043925:Angiogenesis Inducing Agents; D000944:Antigens, Differentiation, B-Lymphocyte; D018932:Chemokine CCL2; D017931:DNA Primers; D000949:Histocompatibility Antigens Class II; D018960:Hyaluronan Receptors; D016209:Interleukin-8; D008263:Macrophage Migration-Inhibitory Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; C045084:invariant chain; D048051:p38 Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases