Effect of a continuously applied compressive pressure on mouse osteoblast-like cells (MC3T3-E1) in vitro

✍ Scribed by Hiroyuki Ozawa; Kazunobu Imamura; Etsuko Abe; Naoyuki Takahashi; Takatoshi Hiraide; Yoshinobu Shibasaki; Tatsuo Fukuhara; Tatsuo Suda

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 817 KB
• Volume: 142
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041420122

✦ Synopsis

Bone metabolism is often affected by a variety of mechanical forces, but the cytological basis of their action is not knomn. In this study, we examined the effect of a continuously applied compressive pressure (CCP) on the growth and differentiation of clonal mouse osteoblast-like cells (MC3T3-El) cultured in a specifically devised culture chamber The gas phase of the chamber was maintained at a pressure of 2 atmosphere5 (atm) above ambient ( 3 atiii total, 3 1 kg/cm2, 3 0 x lo5 Pa) by continuously intusing a compressed mixed gas (0,:

The PO,, pCO,, and pH in the culture medium at 37°C under 3 atm were mdintained at the same levels as those under 1 atm MC3T3-El cells were cultured in a-minimdl essentidl medium containing 10% fetal bovine serum under either 3 atm in the CCP culture chdmber or 1 atm in dn ordinary LO, incubator. Alkaline phosphata5e activity, a marker of osteoblasts, was greatly suppressed by the CCP treatment The inhibition of alkaline phosphatase activitv was rapidly rebtored when the cell5 were transferred to an ordinary CO, incubator under I atm, indicdling that the inhibition of alkaline phosphatasc activity by CCP is reversible Cell growth was not altered under CCP The CCP treatment greatly increased the production and secretion of prostagldndin E, (PGE,). Adding either conditioned medium from the CCP culture or exogenous PCE, to the control culture under 1 atm suppresed alkaline phosphdtase activity dose-dependently The CCP treatment also suppressed collagen synthesis and calcification. These results suggest that CCP causes the cell5 to produce and secrete PGE,, which, in turn, rnhibits ditferentidtion of osteobldsts and the concomitant calcification Bone remodeling is controlled by a wide variety of systemic and local humoral factors such as la,25-dihydroxyvitamin D,, parathyroid hormone, calcitonin, sex hormones, prostaglandins, transforming growth factor-