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231: Expression of relaxin (RLN) and its receptor (RXFP1) in placenta accrete
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Clinical Obstetrics, Medical-Surgical-Disease, Neonatology, Physiology-Endocrinology
Poster Session I
total calcium, phosphorus and parathyroid hormone during and after pregnancy. RESULTS: BMD decreased at the calcaneous bone in the second trimester which recovered in the third trimester. After delivery BMD continued to decrease. Both markers of bone resorption and formation showed increase during pregnancy especially in the third trimester and immediate postpartum. Total calcium level decreased during pregnancy until immediate postpartum and started to recover at postpartum one 1 month. Parathyroid hormone increased during pregnancy and started to decrease after delivery. Phosphorus increased until third trimester, which temporarily decreased at immediate postpartum. CONCLUSION: In twin pregnancy, biochemical markers of bone turnover and bone formation are significantly increased during pregnancy and postpartum and changes in bone metabolism are prominent to meet high fetal demand for calcium.
231 Expression of relaxin (RLN) and its receptor (RXFP1) in placenta accrete
230 Ripening of fetal membranes at term is associated with decreased dystroglycan expression Teresa Walsh1, Shaleen Theiler2, Russell Snyder1, Regan Theiler3 1 The University of Texas Medical Branch, Obstetrics & Gynecology, Galveston, TX, 2The University of Vermont, Department of Medicine, Division of Hematology/Oncology, Burlington, VT, 3Planned Parenthood Northern New England, Medical Director, Williston, VT
OBJECTIVE: Dystroglycan (DG) is an integral component of the transmembrane dystrophin glycoprotein complex, and contributes to the structural stability of plasma membranes. We have demonstrated the presence of DG in human gestational tissues at different gestational ages, but its role has not yet been fully characterized. DG is susceptible to degradation by matrix metalloproteinases 2 and 9, which are increased during labor. The aim of this study is to test the hypothesis that decreased DG expression is seen at term and with onset of labor, due to increased DG cleavage. STUDY DESIGN: Fetal membranes (FM) were collected from four groups of patients at the time of delivery: term (⬎37 weeks gestation) labored, term unlabored, preterm (⬍ 36 weeks gestation) labored, and preterm unlabored. Amnion and chorion were sampled proximal and distal to the site of membrane rupture. Immunohistochemistry was performed using antibodies specific for ␣- and -DG subunits. Intensity was graded by a blinded pathologist, and univariate and multivariate analysis was performed using SAS version 9.2. RESULTS: Both ␣- and -DG were demonstrated in FM throughout the second and third trimesters. Expression of ␣- and -DG was significantly decreased in patients who delivered at term and after spontaneous rupture of membranes (SROM) (P⬍⬍0.05). A trend toward decreased DG expression was detected in patients with preterm premature rupture of membranes (PPROM), but was not statistically significant. The distance from the site of rupture did not affect DG expression. CONCLUSION: Decreased DG expression was seen in FM in those patients who were term and underwent SROM. We theorize that the reduced DG in the chorion leads to a ripening of FM by altering tensile strength and eventually leading to ROM. Further studies are necessary to identify the particular enzymes involved, but it is likely that MMPs play a critical role.
William Goh1, Sandy Yamamoto2, Karen Thompson3, Gillian Bryant-Greenwood2 1 University of Hawaii John A Burns School of Medicine, Obstetrics, Gynecology & Women’s Health, Honolulu, HI, 2 University of Hawaii John A. Burns School of Medicine, Ob/Gyn & Women’s Health, Honolulu, HI, 3University of Hawaii John A. Burns School of Medicine, Pathology, Honolulu, HI
OBJECTIVE: RLN and RXFP1 are expressed in the basal plate (BP) and the syncytiotrophoblast of the placenta. RLN is known to cause collagen dissolution and may be involved in trophoblastic invasion. In placenta accreta, the BP is missing which allows the trophoblast (TR) to invade into myometrium. We sought to define the expression of RLN and RXFP1 in normal placental TR and BP throughout gestation and to compare their expression in TR and BP in placenta accretas, with tissues of the same gestational ages. STUDY DESIGN: Samples of TR and BP were collected into RNAlater after 1st (n⫽5) and 2nd trimester abortions (n⫽5), preterm deliveries (30-34wks gestation, n⫽ 6) and term deliveries (elective CD, n⫽5 and NSVD, n⫽5). Samples were also obtained from placenta accretas (n⫽3) after hysterectomy (20-34 wks). TR was obtained from the invasive areas and TR and BP from the non-invasive areas of accretas. Total RNA was isolated and its quality assessed prior to use in quantitative RT-PCR. cDNA was synthesized and specific primers used for RLN, RXFP1, and 18S. Samples were assayed in triplicate and results normalized to the expression of 18S in each sample. The data was expressed as the n-fold difference relative to 18S and results analyzed by Mann-Whitney and Kruskal-Wallis tests. RESULTS: Expression of RLN and RXFP1 were low in both TR and BP throughout gestation, but RLN was significantly increased (P⬍0.05) in both TR and BP in pregnancies complicated by PPROM, as previously shown in the fetal membranes by this lab. In accretas, both RLN and RXFP1 were significantly elevated in the BP (P⬍0.05), but not in the TR, compared to tissues of the same gestational ages and after elimination of the elevated PPROM samples. CONCLUSION: RLN but not RXFP1 expression was upregulated in both TR and BP in PPROM, as would be expected from previous studies. However, RLN and RXFP1 were both significantly increased in the BP, but not in the TR of accretas, suggesting that RLN may have a role in the pathologic dissolution of the BP in placenta accretas. Supported by grant NIH/NCRR 5P20RR024206.
Supplement to JANUARY 2012 American Journal of Obstetrics & Gynecology
S113
Clinical Obstetrics, Medical-Surgical-Disease, Neonatology, Physiology-Endocrinology
Poster Session I
total calcium, phosphorus and parathyroid hormone during and after pregnancy. RESULTS: BMD decreased at the calcaneous bone in the second trimester which recovered in the third trimester. After delivery BMD continued to decrease. Both markers of bone resorption and formation showed increase during pregnancy especially in the third trimester and immediate postpartum. Total calcium level decreased during pregnancy until immediate postpartum and started to recover at postpartum one 1 month. Parathyroid hormone increased during pregnancy and started to decrease after delivery. Phosphorus increased until third trimester, which temporarily decreased at immediate postpartum. CONCLUSION: In twin pregnancy, biochemical markers of bone turnover and bone formation are significantly increased during pregnancy and postpartum and changes in bone metabolism are prominent to meet high fetal demand for calcium.
231 Expression of relaxin (RLN) and its receptor (RXFP1) in placenta accrete
230 Ripening of fetal membranes at term is associated with decreased dystroglycan expression Teresa Walsh1, Shaleen Theiler2, Russell Snyder1, Regan Theiler3 1 The University of Texas Medical Branch, Obstetrics & Gynecology, Galveston, TX, 2The University of Vermont, Department of Medicine, Division of Hematology/Oncology, Burlington, VT, 3Planned Parenthood Northern New England, Medical Director, Williston, VT
OBJECTIVE: Dystroglycan (DG) is an integral component of the transmembrane dystrophin glycoprotein complex, and contributes to the structural stability of plasma membranes. We have demonstrated the presence of DG in human gestational tissues at different gestational ages, but its role has not yet been fully characterized. DG is susceptible to degradation by matrix metalloproteinases 2 and 9, which are increased during labor. The aim of this study is to test the hypothesis that decreased DG expression is seen at term and with onset of labor, due to increased DG cleavage. STUDY DESIGN: Fetal membranes (FM) were collected from four groups of patients at the time of delivery: term (⬎37 weeks gestation) labored, term unlabored, preterm (⬍ 36 weeks gestation) labored, and preterm unlabored. Amnion and chorion were sampled proximal and distal to the site of membrane rupture. Immunohistochemistry was performed using antibodies specific for ␣- and -DG subunits. Intensity was graded by a blinded pathologist, and univariate and multivariate analysis was performed using SAS version 9.2. RESULTS: Both ␣- and -DG were demonstrated in FM throughout the second and third trimesters. Expression of ␣- and -DG was significantly decreased in patients who delivered at term and after spontaneous rupture of membranes (SROM) (P⬍⬍0.05). A trend toward decreased DG expression was detected in patients with preterm premature rupture of membranes (PPROM), but was not statistically significant. The distance from the site of rupture did not affect DG expression. CONCLUSION: Decreased DG expression was seen in FM in those patients who were term and underwent SROM. We theorize that the reduced DG in the chorion leads to a ripening of FM by altering tensile strength and eventually leading to ROM. Further studies are necessary to identify the particular enzymes involved, but it is likely that MMPs play a critical role.
William Goh1, Sandy Yamamoto2, Karen Thompson3, Gillian Bryant-Greenwood2 1 University of Hawaii John A Burns School of Medicine, Obstetrics, Gynecology & Women’s Health, Honolulu, HI, 2 University of Hawaii John A. Burns School of Medicine, Ob/Gyn & Women’s Health, Honolulu, HI, 3University of Hawaii John A. Burns School of Medicine, Pathology, Honolulu, HI
OBJECTIVE: RLN and RXFP1 are expressed in the basal plate (BP) and the syncytiotrophoblast of the placenta. RLN is known to cause collagen dissolution and may be involved in trophoblastic invasion. In placenta accreta, the BP is missing which allows the trophoblast (TR) to invade into myometrium. We sought to define the expression of RLN and RXFP1 in normal placental TR and BP throughout gestation and to compare their expression in TR and BP in placenta accretas, with tissues of the same gestational ages. STUDY DESIGN: Samples of TR and BP were collected into RNAlater after 1st (n⫽5) and 2nd trimester abortions (n⫽5), preterm deliveries (30-34wks gestation, n⫽ 6) and term deliveries (elective CD, n⫽5 and NSVD, n⫽5). Samples were also obtained from placenta accretas (n⫽3) after hysterectomy (20-34 wks). TR was obtained from the invasive areas and TR and BP from the non-invasive areas of accretas. Total RNA was isolated and its quality assessed prior to use in quantitative RT-PCR. cDNA was synthesized and specific primers used for RLN, RXFP1, and 18S. Samples were assayed in triplicate and results normalized to the expression of 18S in each sample. The data was expressed as the n-fold difference relative to 18S and results analyzed by Mann-Whitney and Kruskal-Wallis tests. RESULTS: Expression of RLN and RXFP1 were low in both TR and BP throughout gestation, but RLN was significantly increased (P⬍0.05) in both TR and BP in pregnancies complicated by PPROM, as previously shown in the fetal membranes by this lab. In accretas, both RLN and RXFP1 were significantly elevated in the BP (P⬍0.05), but not in the TR, compared to tissues of the same gestational ages and after elimination of the elevated PPROM samples. CONCLUSION: RLN but not RXFP1 expression was upregulated in both TR and BP in PPROM, as would be expected from previous studies. However, RLN and RXFP1 were both significantly increased in the BP, but not in the TR of accretas, suggesting that RLN may have a role in the pathologic dissolution of the BP in placenta accretas. Supported by grant NIH/NCRR 5P20RR024206.
Supplement to JANUARY 2012 American Journal of Obstetrics & Gynecology
S113