Intermedin / AM2 in Human Pregnancy

说明(申请人提供)：降钙素(CT)、降钙素基因相关肽CGRP、胰淀素和肾上腺髓质素(AM)属于一组独特的多肽、激素，对体内平衡非常重要。中介素(IMD)或肾上腺髓质素(An/k)是2004年由两组独立同时发现的CT/CGRP多肽家族的新成员。IMD通过CGRP和AM受体复合体发挥作用，具有类似AM的内含子-外显子结构IMD存在于大鼠和小鼠的血液循环中，水平高于AMIMD通过共同的受体复合体发挥作用，可能具有与CGRP和AM相似或重叠的生物学功能事实上，与AM和CGRP一样，IMD被报道能降低正常和高血压大鼠的血压，具有心脏保护作用，抑制胃排空和食物摄取，并受雌激素调节。最近的研究表明，IMD基因在包括子宫和卵巢在内的多种组织中都有表达，提示其可能在女性生殖功能中发挥作用。我们利用大鼠模型进行的初步研究表明，大鼠血浆中IMD的循环水平受妊娠调节，IMD mRNA在着床部位和胎盘中表达，并在胎盘中受妊娠调节。此外，孕15天至18天输注VEVD拮抗剂(IMDi7.47)后，胎盘和胎儿体重明显下降，胎盘生长因子(P1GF)和血管内皮生长因子蛋白(VEGF)表达明显下降，胎盘形态受损。我们实验室进一步的前期研究表明，IMD mRNA在妊娠早期的HTR-8/SV NEO滋养层细胞、绒毛膜癌JAR细胞和妊娠晚期的人胎盘绒毛组织中均有表达。这些观察结果使我们假设IMD在人类妊娠中起作用，特别是血浆IMD、胎盘VED及其受体的水平随着妊娠的推进而增加，这些增加在先兆子痫和/或IUGR的妇女中受到影响。这项研究的具体目的是：具体目标1：确定妇女循环中免疫反应性IMD水平是否随着妊娠的增加而增加，产后减少。特定目的2：检测IMD及其受体的mRNA和蛋白水平，鉴定IMD受体的结合部位，并证实它们在不同孕期胎盘中的细胞定位。目的3：探讨子痫前期、IUGR及子痫前期合并IUGR患者的血浆IMD水平及胎盘组织中IMD及其受体成分的表达水平是否低于年龄匹配的正常孕妇，并检测正常、IUGR、子痫前期及子痫前期合并IUGR孕妇脐血中VIED的浓度及其与新生儿体重的关系。

DESCRIPTION (provided by applicant): Calcitonin (CT), calcitonin gene related peptide CGRP, amylin and adrenomedullin (AM) belong to a unique group of peptide, hormones, important for homeostasis. A new member of CT/CGRP peptide family, intermedin (IMD) or adrenomedullini (AN/k), was discovered in 2004 independently and simultaneously by two groups. IMD functions through both, CGRP and AM receptor complexes and possesses intron-exon structures similar to AM. IMD is present in rat and mice blood circulation at a level higher than AM. Functioning through common receptor complexes, IMD may have biological functions similar to, or overlapping with CGRP and AM. Indeed, like to AM and CGRP, IMD in reported to lower blood pressure in normal and hypertensive rats, exhibits cardioprotective effects and suppress gastric emptying and food intake and is regulated by estrogen. Recent reports show that IMD mRNA is expressed by various tissues including uterus and ovary indicating a possible role of this peptide in female reproductive functions. Our preliminary studies using rat models indicate that circulatory levels of IMD in rat plasma are gestationally regulated, and IMD mRNA is expressed in implantation sites and placenta and is gestationally regulated in placenta. In addition, infusion of EVID antagonist (IMDi7.47) from Day 15 to 18 in pregnant rats caused a significant decline in placental and fetal weights; placental growth factors (P1GF) and vascular endothelial growth factor protein (VEGF) and caused impaired placental morphology. Further pilot studies in our laboratory show that IMD mRNA is expressed in 1st trimester HTR-8/SV neo trophoblast cells, choriocarcinoma JAr cells and 3rd trimester human placental villous tissue. These observations lead us to hypothesize that IMD has a role in human pregnancy, in particular The levels of plasma IMD, placental EVID and its receptors are increased with advancement of gestation and these increases are compromised in women with preeclamptic and/or IUGR. Specific aims of this study are: Specific Aim 1: To determine if circulatory levels of immunoreactive IMD levels in women are increased with pregnancy and decreased post-partum. Specific Aim 2: To assess IMD mRNA and IMD receptor mRNA and protein levels, characterize IMD receptor binding sites, and demonstrate their cellular localization in human placenta on different stages of gestation. Specific Aim 3: To determine if plasma IMD levels and the expression of IMD and its receptor components in placenta are decreased in women with preeclampsia, IUGR, and preeclampsia with IUGR compared to that of age-matched normal women; and to assess plasma concentration of EVID in umbilical cord blood from normal, IUGR, preeclampsia and preeclampsia with IUGR pregnancies and correlate with the infant weights.