TCTP Expression After Rat Spinal Cord Injury: Implications for Astrocyte Proliferation and Migration

Translationally controlled tumor protein (TCTP) is a ubiquitous and highly conserved protein which plays a role in cell proliferation and growth, apoptosis, and cell cycle regulation. However, its expression and function in spinal cord injury (SCI) are still unknown. Here, we demonstrated that expression of TCTP was dynamic changed after acute spinal cord injury. Our results showed that TCTP gradually increased, reached a peak at 3 day, and then declined to basal levels at 14 days after spinal cord injury. Upregulation of TCTP was accompanied with an increase in the levels of proliferation proteins such as PCNA. Immunofluorescent labeling also showed that TCTP located in astrocytes and traumatic SCI induced TCTP colocalizated with PCNA. These results indicated that TCTP might play an important role in astrocyte proliferation. To further probe the role of TCTP, TCTP-specific siRNA-transfected astrocytes showed significant decrease of primary astrocyte proliferation. Surprisingly, TCTP knockdown also reduced primary astrocyte migration, as the reorganization of microtubules and F-actin was disturbed after siRNA transfection. All above indicated that TCTP might play a crucial role in astrocyte proliferation and migration. Collectively, our data suggested that TCTP might play important roles in CNS pathophysiology after SCI.