Multi-scale numerical simulation on mechano-transduction of osteocytes in different gravity fields

Area of Science:

• Biomedical Engineering
• Mechanobiology
• Cell Biology

Background:

• Osteocytes, crucial cells within bone tissue, are responsible for sensing mechanical stimuli.
• Understanding mechano-transduction in osteocytes is vital for bone health and disease research.
• The role of the lacunar-osteocyte complex and its components in mechanical signal amplification requires further investigation.

Purpose of the Study:

• To establish a 3D model of the bone lacunar-osteocyte system to investigate mechano-transduction.
• To analyze the amplification mechanisms of the osteocyte process and primary cilium under varying gravity conditions.
• To determine the optimal mechanical receptor within the osteocyte system.

Main Methods:

• Development of a 3D computational model of the single bone lacunae-osteocyte system.
• Simulation of fluid shear stress (FSS) and mechanical stress distribution within the model.
• Analysis of stress concentration and amplification effects at micro- and nano-scales.

Main Results:

• Significant stress concentration was identified at the physical connection between the transverse element structure (TES) and the osteocyte process.
• Fluid shear stress (FSS) was approximately two orders of magnitude higher in these areas compared to others.
• The osteocyte process demonstrated a significant amplification effect, identified as the 'optimal mechanical receptor'.
• A notable decrease in the mechanical signal conduction ability of the osteocyte system was observed in simulated microgravity.

Conclusions:

• The transverse element structure (TES) plays a critical role in amplifying mechanical stimuli to the osteocyte process.
• Osteocyte processes are more effective mechanical receptors than primary cilia.
• Reduced mechanical signal conduction in microgravity has significant implications for osteocyte function and bone adaptation.