Effect of Fluid Shear Stress on the expression of bone markers in MLO-Y4 Osteocyte-Like Cells

Abstract

Objective Objective To study the expression of several bone markers in osteocytes (MLO-Y4) and osteoblast (MOB) also the effect from fluid shear stress in osteocytes. Methods Reverse transcription-polymerase chain reaction analysis indicate the expression differences between MLO-Y4 cells and MOB cells also before and after fluid shear stress in MLO-Y4 cells. Results MLO-Y4 cells appear to express relatively greater amounts of mRNA for osteocalsin (OCN), osteopontin (OPN) and alkaline phosphatase (ALP) but less amounts for osteoprotegerin (OPG) than MOB cells. Although the receptor activator of nuclear factor kappa B ligand (RANKL) mRNA expression is more in MOB, the ratio of RANKL to OPG mRNA is greater in the MLO-Y4 cells. Fluid shear stress up regulates the expression of RANKL and OPN mRNA but down regulates ALP and OCN mRNA expression significantly in MLO-Y4 cells and also make some changes in OPG. Conclusions The properties of MLO-Y4 cell's are more like osteocytes than osteobiast. The expression of ALP,OCN,OPN and the ratio of RANKL/OPG in MLO-Y4 ceils changed when exposed to fluid shear stress, which suggest osteocytes play a very important role in bone remodlling.