Pressure regulates osteoclast formation and MCSF expression in marrow culture

J Cell Physiol. 1997 Jan;170(1):81-7. doi: 10.1002/(SICI)1097-4652(199701)170:1<81::AID-JCP9>3.0.CO;2-H.

Abstract

One of the forces generated during skeletal loading is hydrostatic pressure. In the work presented here, the ability of increased pressure to influence recruitment of osteoclasts was evaluated. Murine marrow cultures, with pO2 and pCO2 kept constant, were subjected to either control (1.0 atm) or elevated (1.37 or 2.0 atm) hydrostatic pressure. As compared to control, cultures pressurized for 6 days at 1.37 atm formed less osteoclast-like cells (OCLC) (71 +/- 6% of control, P < 0.0001). A similar degree of inhibition occurred in cultures exposed to pressure during days 2-4 only (62 +/- 6%), while treatment during days 5-7 failed to inhibit the OCLC number relative to control (99 +/- 5%). Delivery of 2.0 atm pressure on days 2-4 generated 52 +/- 4% OCLC compared to control. Since macrophage colony stimulating factor (MCSF)-dependent proliferation of osteoclast precursors occurs during the pressure-sensitive period, semiquantitative RT-PCR for MCSF mRNA was performed after 3 days in 1.37 atm (days 2-4). As compared to controls, pressure caused a decrease in mRNA coding for the membrane bound form of MCSF (71.2 +/- 4% (n = 25, P < or = 0.05), while the MCSF RT-PCR product representing the secreted form showed no consistent change. This lack of response of the soluble MCSF RT-PCR product was expected, as levels of bioassayable MCSF were not altered by pressure. Extrapolating these data to in vivo conditions suggests that load-bearing will inhibit the formation of osteoclasts.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Atmospheric Pressure
  • Bone Marrow Cells*
  • Cell Differentiation / physiology
  • Cell Division / physiology
  • Cells, Cultured / cytology
  • Cells, Cultured / physiology
  • Gene Expression Regulation / physiology
  • Hydrostatic Pressure
  • Macrophage Colony-Stimulating Factor / genetics*
  • Macrophage Colony-Stimulating Factor / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Osteoclasts / cytology*
  • Osteoclasts / physiology
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism
  • Stress, Mechanical
  • Time Factors

Substances

  • RNA, Messenger
  • Macrophage Colony-Stimulating Factor