Parathyroid hormone-like hormone (PTHLH) represses decidualization of human uterine fibroblast cells by an autocrine/paracrine mechanism.
BACKGROUND
Parathyroid hormone-like hormone (PTHLH) is abundantly expressed by human endometrial stromal cells during decidualization. However, the role for PTHLH in the decidualization process is unknown.


OBJECTIVE
To examine the effects of PTHLH on the induction and maintenance of decidualization of human uterine fibroblast (HUF) cells in vitro.


METHODS
HUF cells were treated with a PTHLH siRNA or a PTHLH receptor antagonist (bPTH(7-34)) before or after decidualization with medroxyprogesterone acetate (MPA), estradiol (E(2)), and prostaglandin E(2) (PGE(2)). Decidualization was monitored by immunocytochemistry and the induction of decidualization-specific marker genes, including IGFBP-1, prolactin, lefty, and transcription factor FOXO1.


RESULTS
HUF cells decidualized after pretreatment with a PTHLH siRNA showed greater morphologic changes of decidualization, greater IGFBP-1 protein, and two- to threefold more IGFBP-1, prolactin, lefty, and FOXO1 mRNAs than cells pretreated with a nonsilencing RNA. The PTHLH siRNA pretreated cells also had 31% less DNA fragmentation (TUNEL assay) and 30-35% less caspase 3 levels during decidualization than cells pretreated treated with nonsilencing RNA. Treatment of HUF cells with PTHLH siRNA or bPTH(7-34) at 9 d after the induction of decidualization also resulted in 2.1- to 3.2-fold greater IGFBP-1, prolactin, lefty, and FOXO1 mRNA levels than that noted in control cells treated with nonsilencing RNA.


CONCLUSIONS
These finding strongly suggest that PTHLH represses the induction of human decidualization, stimulates stromal cell apoptosis, and limits the extent of uterine stromal cell differentiation. Because PTHLH and its receptor are expressed by HUF cells and placental cells, the inhibitory effect of PTHLH on decidualization appears to be due, at least in part, to an autocrine/paracrine mechanism.
Department of Pediatrics, University of Cincinnati and Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA.
Rosa
R
Sherafat-Kazemzadeh
Jennifer K
JK
Schroeder
Cherie A
CA
Kessler
Stuart
S
Handwerger
D019898:Autocrine Communication / Q000187:drug effects; D053148:Caspase 3 / Q000032:analysis / Q000096:biosynthesis; D002478:Cells, Cultured; D003656:Decidua / Q000187:drug effects*; D005260:Female; D005347:Fibroblasts / Q000187:drug effects*; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D005819:Genetic Markers; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000378:metabolism; D055458:Left-Right Determination Factors / Q000096:biosynthesis; D019899:Paracrine Communication / Q000187:drug effects; D044162:Parathyroid Hormone-Related Protein / Q000494:pharmacology*; D011388:Prolactin / Q000096:biosynthesis; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014599:Uterus / Q000166:cytology / Q000187:drug effects*
C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D005819:Genetic Markers; D018970:Insulin-Like Growth Factor Binding Protein 1; D055458:Left-Right Determination Factors; C470121:PTHLH protein, human; D044162:Parathyroid Hormone-Related Protein; D034741:RNA, Small Interfering; D012313:RNA; D011388:Prolactin; D053148:Caspase 3