Estrogen stimulates differentiation of megakaryocytes and modulates their expression of estrogen receptors α and β

✍ Scribed by Sharyn Bord; Emma Frith; Deborah C. Ireland; Mike A. Scott; Jenny I.O. Craig; Juliet E. Compston

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 203 KB
• Volume: 92
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.20035

✦ Synopsis

Abstract

Estrogen has multifunctional effects influencing growth, differentiation, and function in many tissues. High‐dose estrogen has been shown to produce anabolic skeletal effects in the skeleton of postmenopausal women with increased megakaryocyte (MK) population in the bone marrow, suggesting a possible role for these cells in bone remodelling. To investigate if estrogen stimulates megakaryocytopoiesis and affects on estrogen receptor (ER) expression, CD34(+) cells were cultured for 6, 9, and 14 days plus or minus low‐dose or high‐dose 17β estradiol (E). Cells were immunolocalised for CD61, CD41, ERα and β. ER mRNA expression was assessed by RT‐PCR. Cells formed more CD61 positive MK colonies with low‐ and high‐dose E treatment (P < 0.001) at 6 and 9 days. CD41 expression was increased dose‐dependently in MK (3‐ and 5‐fold P < 0.001) at 9 days. E‐stimulated ERα expression at 6 days (P < 0.001) whilst ERβ was dose‐dependently increased only at 9 days (P < 0.01). ERα mRNA was increased at 6 days but not at 14 days whilst ERβ mRNA expression was only increased at 14 days with E treatment. These results demonstrate that E stimulates the colony forming potential of CD34(+) cells to a more megakaryocytic phenotype in vitro. This finding together with the stimulation of ER protein and mRNA expression adds to the increasing evidence for a role for MKs in estrogen‐induced bone formation. © 2004 Wiley‐Liss, Inc.