Sex-specific response of rat costochondral cartilage growth plate chondrocytes to 17β-estradiol involves differential regulation of plasma membrane associated estrogen receptors

Khairat B.Y. Elbaradie, Yun Wang, Barbara D. Boyan, Zvi Schwartz

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Both male and female rat growth plate chondrocytes express estrogen receptors (ERs); however 17β-estradiol (E2) induces membrane responses leading to activation of phospholipase A2 (PLA2), phospholipase C (PLC), prostaglandin E2 (PGE2) production, protein kinase C (PKC), and ultimately mitogen protein kinase (MAPK) only in female cells. This study investigated if these sex-specific responses are due to differences in the actual ERs or in downstream signaling. Western blots and flow cytometry of costochondral cartilage resting zone chondrocytes (RCs) showed 2-3 times more ERα in plasma membranes (PMs) from female cells than male cells. Tunicamycin blocked E2-dependent ER-translocation to the PM, indicating palmitoylation was required. Co-immunoprecipitation showed E2 induced complex formation between ER isoforms only in female RCs. To examine if the lack of response in PKC and PGE2 in males is due to differences in signaling, we examined involvement of ERs and the role of PLC and PLA2. Selective ERα (propylpyrazole triol, PPT) and ERβ (diarylproprionitrile, DPN) agonists activated PKC in female RCs only. The PLC inhibitor, U73122 blocked E2's effect on PKC and the cytosolic PLA2 inhibitor, AACOCF3 inhibited the effect on PGE2 in female RCs, confirming involvement of PLC and PLA2 in the mechanism. The PLC activator, m-3M3FβS activated PKC and PLAA peptide increased PGE2 levels in male and female RCs, showing that the signaling pathways are present. These data indicate that differences in membrane ER amount, localization, translocation and interaction are responsible for the sexual dimorphic response to E2.

Original languageEnglish (US)
Pages (from-to)1165-1172
Number of pages8
JournalBiochimica et Biophysica Acta - Molecular Cell Research
Volume1833
Issue number5
DOIs
Publication statusPublished - May 1 2013

    Fingerprint

Keywords

  • Distribution of ERα and ERβ in male and female growth plate chondrocytes
  • Estrogen receptor
  • Sex-specific response to 17β-estradiol

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Cite this