Fluid shear stress enhances the cell volume decrease of osteoblast cells by increasing the expression of the ClC-3...

Area of Science:

• Cell Biology
• Biophysics
• Mechanobiology

Background:

• ClC-3 is a critical volume-sensitive chloride channel involved in regulatory cell volume decrease (RVD).
• Osteoblasts are bone-forming cells influenced by mechanical stimuli like fluid shear stress (FSS).
• Understanding ClC-3 channel function in osteoblasts under FSS is crucial for bone mechanotransduction.

Purpose of the Study:

• To investigate the effect of FSS on ClC-3 chloride channel expression and activity in MC3T3-E1 osteoblast cells.
• To determine how FSS influences the RVD process in osteoblasts.
• To elucidate the role of ClC-3 in mediating osteoblast volume changes under mechanical stimulation.

Main Methods:

• MC3T3-E1 cells were subjected to FSS.
• ClC-3 mRNA expression was quantified using fluorescence quantitative polymerase chain reaction.
• Chloride channel activity was assessed using the MQAE fluorescent probe and whole-cell patch clamping.

Main Results:

• FSS significantly increased ClC-3 mRNA expression in osteoblasts compared to controls.
• Mechanical stimulation elevated chloride channel activity, evidenced by reduced MQAE fluorescence and increased chloride ion efflux.
• FSS enhanced osteoblast RVD and increased volume-sensitive chloride currents, correlating with elevated ClC-3 expression.

Conclusions:

• FSS stimulation positively modulates ClC-3 expression and activity in osteoblasts.
• Enhanced ClC-3 function contributes to the increased RVD observed under mechanical stress.
• These findings highlight ClC-3 as a key mediator of osteoblast mechanosensing and volume regulation.