1141478634 Amniochorion secretes chemotactic signals for leukocytes during human labor (original) (raw)
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Choriodecidua and amnion exhibit selective leukocyte chemotaxis during term human labor
American Journal of Obstetrics and Gynecology, 2011
The purpose of this study was to compare the chemotactic activity of the choriodecidua and amnion, and to identify the phenotype of the leukocytes chemoattracted by each tissue. STUDY DESIGN: Amnion, choriodecidua and whole fetal membranes extracts were obtained from women at term (Ͼ37 weeks of gestation) with or without labor (n ϭ 5 each). Extracts were assayed for leukocyte chemotactic activity, and the number and phenotype of the chemoattracted leukocytes were characterized by flow cytometry. RESULTS: Although all of the extracts exhibited chemotactic activity, more leukocytes were chemoattracted by the choriodecidua and the whole fetal membranes during labor compared with no labor (P ϭ .010, .008). During labor the choriodecidua is responsible for granulocyte, Tlymphocyte, monocyte, and natural killer-cell chemoattraction, and the amnion is responsible for B-lymphocyte chemoattraction. CONCLUSION: Choriodecidua and amnion exhibit chemotactic activity for selective leukocytes and thus, each fetal membrane differentially regulates leukocyte chemotactic activity during labor.
Fetal membranes exhibit selective leukocyte chemotaxic activity during human labor
Journal of Reproductive Immunology, 2009
One of the characteristics of the labor process in women is leukocyte recruitment into reproductive tissues. These migrating cells may play a role in the induction of functional and biochemical changes associated with the rupture of fetal membranes during labor. This study was undertaken to assess whether human fetal membranes induce leukocyte chemotaxis during labor as well as to identify and characterize leukocyte chemoattractants secreted by these tissues. Leukocyte chemotactic activity of fetal membrane extracts obtained from women with full-term pregnancies and spontaneous active labor was compared with extracts from women without labor. The number and phenotype of attracted leukocytes were analyzed by flow cytometry. Chemokines were quantified using a Multiplex system and were identified by immunofluorescence histochemistry. Although all tested extracts induced chemotaxis of leukocytes, those prepared from women undergoing labor induced higher responses. Polymorphonuclear leukocyte chemotaxis increased approximately three-fold in response to extract from fetal membranes with labor. The same extracts elicited a significant increase in attracted monocytes (36-fold) as well as T and B lymphocytes, and NK cells (all five-fold) when compared to extracts from women without labor. This enhanced chemotactic activity was associated with the presence of IL-8, MCP-1, IP-10 and MIP-1␣. We conclude that fetal membrane extracts obtained from women during labor exhibit selective chemotaxis for specific leukocyte subpopulations in vitro. This process may contribute to a microenvironment composed of specific leukocytes that promotes and amplifies biochemical changes in the fetal membranes during labor.
The Role of Chemokines in Term and Premature Rupture of the Fetal Membranes: A Review1
Biology of Reproduction, 2010
Several studies indicate that at the choriodecidual interface, where maternal and fetal tissues make contact, a network of signals is established during labor that includes infiltration of leukocytes and secretion of pro-inflammatory cytokines. In this review, we provide an overview of the inflammatory milieu present in the choriodecidua during membrane rupture, describe the recruitment and homing of leukocytes to the reproductive tissues, and detail specific actions of the key chemokines released by the choriodecidual cells. These data lend further support to the hypothesis that labor is an inflammatory response, wherein the infiltrated leukocytes in the choriodecidua interface could be contributing to the creation of a microenvironment leading to collagenolysis, which would promote the rupture of these tissues during labor. In addition to the available information describing biological actions of chemokines during various pathological conditions such as infection, preterm labor and preterm rupture of membranes suggest that these compounds play important roles in other gestational events such as cervical dilation and myometrial contractions. Even though we do not know the totality of biochemical signals that integrate the molecular dialogue between leukocytes and the various gestational tissues, it is becoming increasingly evident that this microenvironment is characterized, at least in part, by the differential expression and secretion of chemokines that induce selective trafficking of leukocyte subsets to the fetal membranes. Therefore, chemokines should be considered as important regulatory molecules with the ability to initiate the events that characterize normal and pathological labor.
Matrix Biology, 2005
Extracellular matrix degradation in fetal membranes leading to its rupture is coupled to myometrial activity and cervical ripening during human normal labor. Mechanisms which modulate collagen degradation in amniochorion during labor have not been elucidated. Initial characterization of the effect of different blood compartments on connective tissue degradation in amniochorion during human labor was explored. Amniochorion explants were stimulated with plasma of maternal venous blood, umbilical cord blood or placental blood, obtained from women with pregnancies at term, with or without labor. MMP-2 and MMP-9 activities were quantified in conditioned media by gelatinzymography as an index of connective tissue degradation. Collagen content was measured in tissue explants and collagen fibrils distribution was examined by electron microscopy. Placental plasma from term pregnancies, with or without labor, is enriched with soluble signals that enhance the in vitro MMP-9 production by amniochorion. Accompanying ultrastructural distortion of collagen fibers and demonstration of collagen degradation fragments confirmed induction of extracellular matrix degradation. Control experiments in which MMP-9 activity was blocked with TIMP-1 resulted in inhibition of all the above mentioned changes. These results suggest that placental intervillous space is a functional compartment in which mediators capable to induce collagen degradation in amniochorion are selectively expressed during human labor. D
Journal of Maternal-fetal & Neonatal Medicine, 2003
Objective: Parturition is characterized by an influx of inflammatory cells into gestational tissues, a phenomenon conducive to increased myometrial contractility, cervical ripening and decidual/ membrane activation. Monocyte chemotactic protein-1 (MCP-1), a potent chemoattractant and activator of monocytes/macrophages, is expressed in gestational tissues and, thus, may participate in the final common pathway of labor. This study was undertaken to determine whether the amniotic fluid concentrations of immunoreactive MCP-1 are altered with gestational age or spontaneous labor at term with and without prelabor rupture of the gestational membranes. We also sought to identify intrapartum differences in the concentrations of immunoreactive MCP-1 between the upper and lower amniotic fluid compartments. Methods: A cross-sectional study was conducted to assess the concentrations of immunoreactive MCP-1 in amniotic fluid. Amniotic fluid samples were obtained from 225 women as follows:
Biology of Reproduction, 2002
Each of the proinflammatory cytokines interleukin (IL)-1, IL-6, IL-8, and tumor necrosis factor (TNF) ␣ has been identified in reproductive tissues during labor. The cellular origin of these cytokines is unclear. The aim of this study was to localize these proinflammatory cytokines in myometrium (upper and lower segment), cervix, and fetal membranes at term. Biopsies were taken from women undergoing cesarean section either before or after the onset of labor. Immunohistochemistry was used to localize each of the cytokines IL-1, IL-6, IL-8, and TNF␣. Leukocytes were localized using an antibody to CD45. In myometrium and cervix, immunostaining for IL-1 was predominantly in leukocytes. In fetal membranes, IL-1 localized to leukocytes and to the stromal cells of the decidua. In myometrium, IL-6, IL-8, and TNF␣ were restricted to leukocytes, which were present in greater numbers in tissue obtained during labor. In cervix, IL-6, IL-8, and TNF␣ localized to leukocytes and glandular and surface epithelium. IL-8 also localized to cervical stromal cells. In fetal membranes, IL-6 and TNF␣ were expressed by decidual stromal cells, infiltrating leukocytes, and extravillous trophoblasts. In membranes, IL-8 localized to leukocytes in the chorion but was not detected in the amnion. In fetal membranes collected at labor, IL-8 was expressed in decidual stromal cells. Infiltrating leukocytes are a major source of cytokines in uterine tissues during labor.