Estradiol influences the mechanical properties of human fetal osteoblasts through cytoskeletal changes

Journal Article · Fri Jul 06 04:00:00 EDT 2012 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2012.05.149· OSTI ID:22207928

Muthukumaran, Padmalosini ^[1]; Lim, Chwee Teck ^[1]; Lee, Taeyong ^[1]

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1. Department of Bioengineering, National University of Singapore (Singapore)

Highlights: Black-Right-Pointing-Pointer Estradiol induced stiffness changes of osteoblasts were quantified using AFM. Black-Right-Pointing-Pointer Estradiol causes significant decrease in the stiffness of osteoblasts. Black-Right-Pointing-Pointer Decreased stiffness was caused by decreased density of f-actin network. Black-Right-Pointing-Pointer Stiffness changes were not associated with mineralized matrix of osteoblasts. Black-Right-Pointing-Pointer Estradiol increases inherent alkaline phosphatase activity of osteoblasts. -- Abstract: Estrogen is known to have a direct effect on bone forming osteoblasts and bone resorbing osteoclasts. The cellular and molecular effects of estrogen on osteoblasts and osteoblasts-like cells have been extensively studied. However, the effect of estrogen on the mechanical property of osteoblasts has not been studied yet. It is important since mechanical property of the mechanosensory osteoblasts could be pivotal to its functionality in bone remodeling. This is the first study aimed to assess the direct effect of estradiol on the apparent elastic modulus (E{sup Asterisk-Operator }) and corresponding cytoskeletal changes of human fetal osteoblasts (hFOB 1.19). The cells were cultured in either medium alone or medium supplemented with {beta}-estradiol and then subjected to Atomic Force Microscopy indentation (AFM) to determine E{sup Asterisk-Operator }. The underlying changes in cytoskeleton were studied by staining the cells with TRITC-Phalloidin. Following estradiol treatment, the cells were also tested for proliferation, alkaline phosphatase activity and mineralization. With estradiol treatment, E{sup Asterisk-Operator} of osteoblasts significantly decreased by 43-46%. The confocal images showed that the changes in f-actin network observed in estradiol treated cells can give rise to the changes in the stiffness of the cells. Estradiol also increases the inherent alkaline phosphatase activity of the cells. Estradiol induced stiffness changes of osteoblasts were not associated with changes in the synthesized mineralized matrix of the cells. Thus, a decrease in osteoblast stiffness with estrogen treatment was demonstrated in this study, with positive links to cytoskeletal changes. The estradiol associated changes in osteoblast mechanical properties could bear implications for bone remodeling and its mechanical integrity.

• OSTI ID: 22207928
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 3 Vol. 423; ISSN BBRCA9; ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ACTIN
ALKALINE PHOSPHATASE
ATOMIC FORCE MICROSCOPY
CELL PROLIFERATION
CONNECTIVE TISSUE CELLS
ESTRADIOL
FLEXIBILITY
IMAGES
MICROTUBULES
MINERALIZATION
SKELETON