Expression Change Of Sam68 And Its Functional Study In Neuronal Apoptosis And Asteocyte Proliferation After Spinal Cord Injury In Rats

Objective The study was designed to investigate the expression changes of Src-associated in mitosis(Sam68)after traumatic spinal cord injury and clarify its function in neuronal apoptosis and asteocyte proliferation of central nervous system(CNS)injury.Methods Sprague-Dawley(SD)rats were subjected to spinal cord injury,expression patterns and distribution of Sam68 were observed by Western Blot,immunohistochemistry and immunofluorescence.In addition,double immunofluorescence labeling was performed to study the relationship of Sam68/Neu N with Caspase-3 and Sam68/GFAP with PCNA to explore their pathological and physiological significance during neuronal apoptosis and asteocyte proliferation after spinal cord injury in rats.Rat primary neurons apoptosis and astrocytes proliferation models were conducted to certify the functions of Sam68 again in the processes of CNS injury.Results1.In the rat traumatic spinal cord injury model,we found a significant increase of Sam68 protein levels in this model,which reached a peak at day 3 and then gradually returned to normal levels at day 14 after SCI;immunohistochemistry analysis revealing a widespread distribution of Sam68 increase in injured group;double immunofluorescence staining showed that Sam68 immunoreactivity was mainly located in neurons and astrocytes.Moreover,colocalization of Sam68/Caspase-3 has been respectively detected in NeuN,and colocalization of Sam68/PCNA has been detected in GFAP.2.In rat primary neurons apoptosis and astrocytes proliferation models,we found the expression changes of Sam68?Caspase-3 and PCNA.During this process,the expression of cell cycle related protein Cyclin D1 also gradually increased with the time points.3.Silencing Sam68 by siRNA could inhibit neuronal apoptosis and asteocyte proliferation through cell cycle.Conclusions The expression of Sam68 has a significant increase after traumatic spinal cord injury.This phenomenon mainly displays in neurons and astrocytes.In this process of neurons apoptosis and astrocytes proliferation,Sam68 may be involved in the activation of the cell cycle.