Ghrelin, a novel placental-derived hormone
Ghrelin, a novel placental-derived hormone
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DOI：
10.1210/en.142.2.788
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发表时间：
2001-02-01
期刊：
影响因子：
4.8
通讯作者：
Casanueva, FF
中科院分区：
文献类型：
--
作者：
Gualillo, O;Caminos, JE;Casanueva, FF
Ghrelin是最近从大鼠胃中发现的一种能释放GH的酰化肽。纯化的肽由28个氨基酸组成，其中丝氨酸3残基是正辛酰化的。在这里，我们表明，ghrelin信使RNA和ghrelin肽存在于人类以及大鼠胎盘。在人胎盘组织中，ghrelin在妊娠早期和分娩后均被PCR检测到。虽然生长素释放肽在足月人胎盘中未被免疫组化检测到，但在早期妊娠中很容易被免疫组化识别，主要表达于细胞滋养层细胞，而在合体滋养层细胞中几乎不表达。Ghrelin也在人绒毛膜癌细胞系BeWo细胞中被鉴定。通过免疫组化发现，在大鼠胎盘迷路滋养层细胞的细胞质中存在Ghrelin，而其他胎盘细胞类型似乎对Ghrelin免疫染色呈阴性。此外，胎盘生长激素释放肽信使RNA，在怀孕大鼠，表现出的特征性的表达几乎无法检测到在怀孕早期，在第16天的表达和下降的最后阶段的怀孕。总之，在人类和大鼠胎盘中检测到生长素释放肽，显示出妊娠相关的表达时间过程。胎盘来源的ghrelin是否参与GH释放的调节，或胎盘细胞的生长和分化仍有待确定。
Ghrelin, a GH-releasing acylated peptide, has been recently identified from the rat stomach. The purified peptide consists of 28 amino acids in which the serine 3 residue is n-octanoylated. Here we show that ghrelin messenger RNA and ghrelin peptide are present in the human as well as in rat placentae. In human placenta, ghrelin was detected by PCR at both first trimester and after delivery. While ghrelin was not detected by immunohistochemistry in human placenta at term, it was easily identified by immunohistochemistry at first trimester being mainly expressed in cytotrophoblast cells and scarcely in syncytiotrophoblast ones. Ghrelin was also identified in a human choriocarcinoma cell Line, the BeWo cells. Ghrelin was found, by immunohistochemistry, in the cytoplasm of labyrinth trophoblast of rat placenta, whereas other placental cell types seems to be negative for ghrelin immunostaining. Moreover, placental ghrelin messenger RNA, in pregnant rats, showed a characteristic profile of expression being practically undetectable during early pregnancy, with a sharp peak of expression at day 16 and decreasing in the latest stages of gestation. In conclusion, ghrelin has been detected in human and rat placenta showing a pregnancy-related time course of expression. Whether placenta-derived ghrelin is involved in the modulation of GH release, or placental cell growth and differentiation remains to be established.