Search

Objectives:Macrophage migration inhibitory factor (MIF), a multifunctional proinflammatory cytokine, has been recently involved in many aspects of reeproduction including pregnancy. However, no evidence is available on the role of MIF in gestational tissues nor on factors regulating MIF production. This study, conducted on explants of human fetal membranes at term gestation, has been undertaken to investigate whether: (1) MIF is produced by fetal membranes; (2) nitric oxide (NO) can regulate local MIF production; and (3) MIF, in turn, can influence NO release in these tissues.Methods:Tissues were obtained from 56 healthy women who underwent elective cesarean delivery. Fetal membranes have been incubated with either sodium nitroprusside (NP), a NO donor, or recombinant MIF (r-MIF), or a specific anti-MIF antibody (MIF-Ab). Reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, enzyme-linked immunosorbent assay (ELISA), and colorimetric assay have been used to detect MIF mRNA and protein, inducible nitric oxide synthase (iNOS), and NO metabolites.Results:Fetal membranes basally express MIF mRNA and protein and release MIF. Exposing tissues to NP results in an increase of MIF mRNA expression and protein release. Conversely, treatment of tissues with MIF is followed by a reduction in iNOS mRNA and protein expression as well as in NO release. These effects are reversed by adding MIF-Ab.Conclusions:MIF is generated and released by human fetal membranes at term. MIF mRNA and protein expression and release are modulated by NO. MIF, in turn, can reduce iNOS expression and NO release by these tissues. NO could be a regulator of MIF production in pregnancy and labor.

Objectives: Macrophage migration inhibitory factor (MIF), a multifunctional proinflammatory cytokine, has been recently involved in many aspects of reproduction including pregnancy. However, no evidence is available on the role of MIF in gestational tissues nor on factors regulating MIF production. This study, conducted on expiants of human fetal membranes at term gestation, has been undertaken to investigate whether: (1) MIF is produced by fetal membranes; (2) nitric oxide (NO) can regulate local MIF production; and (3) MIF, in turn, can influence NO release in these tissues. Methods: Tissues were obtained from 56 healthy women who underwent elective cesarean delivery. Fetal membranes have been incubated with either sodium nitroprusside (NP), a NO donor, or recombinant MIF (r-MIF), or a specific anti-MIF antibody (MIF-Ab). Reverse transcriptase—polymerase chain reaction (RT-PCR), Western blot, enzyme-linked immunosorbent assay (ELISA), and colorimetric assay have been used to detect MIF mRNA and protein, inducible nitric oxide synthase (iNOS), and NO metabolites. Results: Fetal membranes basally express MIF mRNA and protein and release MIF. Exposing tissues to NP results in an increase of MIF mRNA expression and protein release. Conversely, treatment of tissues with MIF is followed by a reduction in iNOS mRNA and protein expression as well as in NO release. These effects are reversed by adding MIF-Ab. Conclusions: MIF is generated and released by human fetal membranes at term. MIF mRNA and protein expression and release are modulated by NO. MIF, in turn, can reduce iNOS expression and NO release by these tissues. NO could be a regulator of MIF production in pregnancy and labor.

Objectives:This study has a twofold aim: 1) to investigate whether protein expression and enzyme activity of phosphodiesterase 4 (PDE5) can be detected in human myometrium and undergo changes in relation to the presence of pregnancy and/or labor; 2) to evaluate whether PDE 5 expression and activity in myometrial cells can be influenced by human chorionic gonadotropin (HCG).Methods:Primary cultures of myometrial cells, obtained from non-pregnant women and from pregnant women at tem, either before or during labor, were carried out in the presence of HCG or dibutyryl-cyclic AMP (ad-cAMP), the non-hydrolizable analogue of cAMP. PDE5 expression in cultures of myometrial cells was detected by immunocytochemistry and western blot. PDE5 activity was detected in cell extracts by enzyme assay.Results:PDE5 is expressed and is functionally active in smooth myscle cells. Treatment of cell cultures with HCG and db-cAMP results in a reduction of PDE5 expression and activity. The effects of HCG and db-cAMP are exerted irrespective of the functional status of the myometrium (n0n-pregnant, pregnant not in labor, pregnant in labor).Conclusions:PDE5 protein is expressed in human non-pregnant and pregnant myometrium. HCG reduces PDE5 expression and enzyme activity in smooth muscle cells, possibly through a pathway involving cAMP

Objective: This study has a twofold aim:1i) to investigate whether protein expression and enzyme activity of phosphodiesterase 5 (PDE5) can be detected in human myometrium and undergo changes in relation to the presence of pregnancy and/or labor; 2) to evaluate whether PDE5 expression and activity in myometrial cells can be influenced by human chorionic gonadotropin (HCG). Methods: Primary cultures of myometrial cells, obtained from non-pregnant women and from pregnant women at term, either before or during labor, were carried out in the presence of HCG or dibutyryl-cyclic AMP (db-cAMP), the non-hydrolizable analogue of cAMP. PDE5 expression in cultures of myometrial cells was detected by immunocytochemistry and western blot. PDE5 activity was detected in cell extracts by enzyme assay. Results: PDE5 is expressed and is functionally active in smooth muscle cells. Treatment of cell cultures with HCG and db-cAMP results in a reduction of PDES expression and activity. The effects of HCG and db-cAMP are exerted irrespective of the functional status of the myometrium (non-pregnant, pregnant not in labor, pregnant in labor). Conclusion: PDE5 protein is expressed in human non-pregnant and pregnant myometrium. HCG reduces PDE5 expression and enzyme activity in smooth muscle cells, possibly through a pathway involving cAMP.