Johnny Zhang


Phone: 647-839-0896


2010 – present

M.A.Sc., Institute of Biomaterials and Biomedical Engineering, University of Toronto
Supervisor: L. You

2005 – 2010
B.A.Sc., Engineering Science – Biomedical Engineering Major, University of Toronto


Osteocytes as Mechanosensory Cells: Involvement of S1P Cascade

Osteocytes embedded in the lacunae of bone mineralized matrix are believed to be the mechanosensory cells responsible for converting mechanical stimuli into biochemical signals, which regulate bone remodelling. However, the underlying signalling pathways of this process remain unknown. Sphingosine-1-phosphate (S1P) is a bioactive lipid mediator important for cell growth and survival, angiogenesis, and many other biological processes. S1P is mediated by a family of 5 highly specific G-protein-coupled receptors (GPCRs). S1P can modify intracellular calcium levels by either directly enter the cells or act as a second messenger. We hypothesize that the S1P cascade may be involved in the ostecyte-regulated mechanotransduction. Osteocytes will be cultured in flow chambers that mimic the lacunae-canalicular structure of osteocytes in vivo. The cells will be exposed to oscillatory fluid flow (OFF) for 2 hours, gene expression of bone formation and resorption markers will be quantified.