Gene expression profile of oligodendrocytes in vitro in early stage after ionizing irradiation

Objective: To characterize the gene expression in acute phase of irradiated oligodendrocytes (OL) in vitro. Methods: The total RNA was extracted from irradiated OLs with 10 Gy by 6 MV X-rays at 1 and 4 h. The Affymetrix RAT 230 2.0 microarray were used to evaluate and screen the gene expression profile. The quantitative real-time RT-PCR was performed to validate the microarray results of selected myelin basic protein (MBP) and neural cell adhesion molecule 1 (NCAM-1) genes. Results: Compared with un-irradiated OLs, there were 1079 different expressed genes in irradiated cells. Those genes were classified in 79 categories based on the functional classification. Some familiar genes associated with OL cellular physiological process, apoptosis, cell cycle control, metabolism, cell communication and receptor binding were included. Compared with the microarray results, the coincidence rate of real-time RT-PCR was 91.7%. The down-regulation of MBP and up-regulation of NCAM 1 gene expression were confirmed. Conclusions: Radiation-induced changes in gene expression in OLs took place in acute phase and influenced by time-course. The changes of MBP and NCAM 1 gene expression may play a key role in the pathogenesis of radiation-induced demyelination. (authors)