W G Cao1, M Morin, V Sengers, C Metz, T Roger, R Maheux, A Akoum. 1. Unité d'endocrinologie de la reproduction, Centre de Recherche, Hôpital Saint-François d'Assise, Centre Hospitalier Universitaire de Québec, Faculté de Médecine, Université Laval, Québec, Canada.
Abstract
BACKGROUND: A series of controlled changes including proliferation, secretion and menstrual shedding occur in the human endometrium during every normal menstrual cycle. Macrophage migration inhibitory factor (MIF), a multifunctional cytokine with numerous proinflammatory, immunomodulatory and angiogenic properties, appears to be expressed in the human endometrium and to follow a regulated cycle phase-dependent expression, but the mechanisms underlying endometrial MIF expression remain to be fully elucidated. METHODS AND RESULTS: Results from enzyme-linked immunosorbent assay (ELISA) demonstrated a significant dose- and time-dependent increase in MIF secretion by human endometrial cells in response to tumour necrosis factor-alpha (TNF-alpha) (0.1-100 ng/ml). This increase was also observed at the mRNA level as shown by reverse transcription (RT)-PCR. Curcumin (10(-8) mol/l), a known nuclear factor (NF)-kappaB inhibitor, inhibited the TNF-alpha-induced pIkappaB phosphorylation as shown by western blotting, NF-kappaB translocation into the nucleus as shown by electrophoretic mobility shift assay, and MIF synthesis and secretion as measured by ELISA and RT-PCR. The expression of a dominant-negative NF-kappaB inhibitor (IkappaB) significantly decreased the TNF-alpha-induced MIF promoter activity as analysed by transient cell transfection. CONCLUSIONS: These results indicate clearly that TNF-alpha up-regulates the expression of MIF in endometrial stromal cells. This took place possibly through NF-kappaB activation, and may play an important role in the physiology of the human endometrium.
BACKGROUND: A series of controlled changes including proliferation, secretion and menstrual shedding occur in the human endometrium during every normal menstrual cycle. Macrophage migration inhibitory factor (MIF), a multifunctional cytokine with numerous proinflammatory, immunomodulatory and angiogenic properties, appears to be expressed in the human endometrium and to follow a regulated cycle phase-dependent expression, but the mechanisms underlying endometrial MIF expression remain to be fully elucidated. METHODS AND RESULTS: Results from enzyme-linked immunosorbent assay (ELISA) demonstrated a significant dose- and time-dependent increase in MIF secretion by human endometrial cells in response to tumour necrosis factor-alpha (TNF-alpha) (0.1-100 ng/ml). This increase was also observed at the mRNA level as shown by reverse transcription (RT)-PCR. Curcumin (10(-8) mol/l), a known nuclear factor (NF)-kappaB inhibitor, inhibited the TNF-alpha-induced pIkappaB phosphorylation as shown by western blotting, NF-kappaB translocation into the nucleus as shown by electrophoretic mobility shift assay, and MIF synthesis and secretion as measured by ELISA and RT-PCR. The expression of a dominant-negative NF-kappaB inhibitor (IkappaB) significantly decreased the TNF-alpha-induced MIF promoter activity as analysed by transient cell transfection. CONCLUSIONS: These results indicate clearly that TNF-alpha up-regulates the expression of MIF in endometrial stromal cells. This took place possibly through NF-kappaB activation, and may play an important role in the physiology of the human endometrium.