Expression of leptin receptor in human endometrium and fluctuation during the menstrual cycle.
Leptin is secreted by adipocytes and regulates appetite through interaction with hypothalamic leptin receptors (OB-R). Accumulated evidence shows that leptin is involved in the stimulation of reproductive functions and that local expression of leptin and OB-R in the ovary, oocyte, embryo, and placenta plays a role in early development. To investigate the role of leptin in implantation, we examined the expression of OB-R and leptin in the human endometrium. Northern and Western blot analyses and RT-PCR showed that the long form of OB-R (OB-R(L)) messenger ribonucleic acid (mRNA) and protein were expressed. In contrast, leptin mRNA or protein was not detected. All of the splice variants of OB-R (OB-R(T)) and OB-R(L) transcripts were expressed in 90% and 84% of the cases, respectively. OB-R mRNA expression peaked in the early secretory phase. Decidual tissue of early gestation also expressed OB-R(T) and OB-R(L). Their incidence and abundance were comparable among endometria with benign uterine diseases and disease-free endometria and were not related to a body mass index within the normal range. The present results indicate that OB-R, but not leptin, is expressed in the human endometrium.
Kitawaki
J
J
Department of Obstetrics and Gynecology, Kyoto Prefectural University of Medicine, Japan. kitawaki@koto.kpu-m.ac.jp
Koshiba
H
H
Ishihara
H
H
Kusuki
I
I
Tsukamoto
K
K
Honjo
H
H
D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D004715:Endometriosis / Q000235:genetics / Q000378:metabolism; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D007031:Hypothalamus / Q000502:physiology; D007889:Leiomyoma / Q000235:genetics* / Q000378:metabolism; D008597:Menstrual Cycle / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014591:Uterine Diseases / Q000235:genetics* / Q000378:metabolism; D014594:Uterine Neoplasms / Q000235:genetics* / Q000378:metabolism
D002352:Carrier Proteins; C515448:LEPR protein, human; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D054411:Receptors, Leptin