Effects of Mechanical Force on Cytoskeleton Structure and Calpain-Induced Apoptosis in Rat Dorsal Root Ganglion Neurons In Vitro

Background: A sudden mechanical insult to the spinal cord is usually caused by changing pressure on the surface of the spinal cord. Most of these insults are mechanical force injuries, and their mechanism of injury to the spinal cord is largely unknown. Methods: Using a compression-driven instrument to simulate mechanical force, we applied mechanical pressure of 0.5 MPa to rat dorsal root ganglion (DRG) neurons for 10 min to investigate cytoskeletal alterations and calpain-induced apoptosis after the mechanical force injury. Results: The results indicated that mechanical forces affect the structure of the cytoskeleton and cell viability, induce early apoptosis, and affect the cell cycle of DRG neurons. In addition, the calpain inhibitor PD150606 reduced cytoskeletal degradation and the rate of apoptosis after mechanical force injury. Conclusion: Thus, calpain may play an important role in DRG neurons in the regulation of apoptosis and cytoskeletal alterations induced by mechanical force. Moreover, cytoskeletal alterations may be substantially involved in the mechanotransduction process in DRG neurons after mechanical injury and may be induced by activated calpain. To our knowledge, this is the first report to demonstrate a relationship between cytoskeletal degradation and apoptosis in DRG neurons.