Osteocytes Use Estrogen Receptor α to Respond to Strain but Their ERα Content Is Regulated by Estrogen

摘要: The role of mechanical strain and estrogen status in regulating ERα levels bone cells was studied female rats. OVX is associated with decreased protein expression/osteocyte, whereas habitual artificial loading has only a small but positive effect, except on the ulna's medial surface, where stimulates reversal resorption to formation. Introduction: Osteoporosis most widespread failure bones' ability match their architectural strength load bearing. In men women, severity loss bioavailability estrogen. This association could result from receptor (ER) involvement cells' adaptive response loading. Materials Methods: vivo semiquantitative analysis amount per osteocyte performed immuno-cytochemically stained sections control loaded rat ulna, as well tibias ovariectomy (OVX) sham-operated vitro, effect exogenous (10−8 M) (3400 μϵ, 1 Hz, 600 cycles) expression mRNA assessed ROS 17/2.8 monolayers using real-time PCR ER promoter activity. translocation both MLO-Y4 cells. Results: More than 90 percent tibial osteocytes express ERα, level/osteocyte being higher cortical cancellous bone. ulna that caused by had formation. unstimulated osteoblasts situ, osteocyte-like osteoblast-like predominantly cytoplasmic. stimulate transient nucleus changes mRNA. Strain not also induces discrete membrane localization ERα. Conclusions: Bone responses involve regulates its cellular concentration. consistent hypothesis deficiency consequence reduction number/activity lower concentration reducing effectiveness anabolic strain.