The expression of phosphatase and tensin homologue deleted on chromosometen/mammalian target of rapamycin signaling pathway in the spinal cord of rats during the development

Abstract

Objective To observe the expression pattern of phosphatase and tensin homologue deleted on chromosometen(PTEN)/mammalian target of rapamycin(mTOR)pathway in the spinal cord of SD rats. Methods We dissected spinal cords of rats at developmental stages E15, P0, P7 and P56,and applied Western blotting to detect the expression levels of critical target proteins on the pathway. Furthermore, immunofluorescence was used to detect the cellular localization of these targets in the spinal cord. Results The ratio of gray value for PTEN to actin was 0.281±0.086,0.462±0.002,0.591±0.022 and 0.392±0.001 from E15 to P56. There was statistically significant difference between each two groups except for P0 and P7. The ratio of gray value for S6 to actin was 0.646±0.116,0.450±0.129,0.824±0.082 and 0.174±0.038 from E15 to P56. There was statistically significant difference between P56 to E15 and P7.Meanwhile neurons in the spinal cord of rats were found to be abundant of PTEN and S6 expression with immunofluorescence method. Conclusion Our data showed a development-related expression pattern of PTEN/mTOR signaling pathway in the spinal cord of rats. These results may provide a factual basis for the etiology of the decrease of intrinsic regeneration ability of central nervous system(CNS)along with development, and supply some thread for therapy after spinal cord injury. Key words: Phosphatase and tensin homologue deleted on chromosometen; S6; Spinal cord injury; Axonal regeneration