Differentially expressed genes in intestinal epithelial cells derived from mice with mild intestinal type of radiation sickness

Objective: To study the differentially expressed gene profiles by intestinal epithelial cells (IECs) derived from mice with mild intestinal type of radiation sickness. Methods: Total RNA of IECs obtained from normal animals and mice at 3 h, 96 h after 12 Gy γ-ray irradiation was isolated by Chomzynski's method and mRNA was purified using magnetic bead method. High specific activity 32P-cDNA probes (0.5 x 106 cpm/μg) were made by a single round reverse transcription with 200 U of Moloney murine leukemia virus reverse transcriptase in the presence of CDS primer (Clontech Co). The 32P-cDNA probes were hybridized to the microarry membrane which contains 588 genes. After scanning the hybridization signal by gel analysis system, the differentially expressed gene profiles of the IECs derived from mice at 3 h, 96 h after 12 Gy γ-ray irradiation were made. Results: The differentially expressed gene profiles showed that the γ-ray induced gene expression pattern at the early stage (3 h) by IECs represented mainly inhibition of gene expression. The results of the differential gene expression mainly represented the IECs damage and resistance to radiation damage. At the IECs regeneration stage (96 h after irradiation), the differentially expressed genes mainly exhibited increase of gene expression and appearance of new gene expression. Besides, cdk inhibitor I protein gene remained at a stably high level of expression during radiation injury. Conclusion: The differential gene expression at the regeneration stage after 12 Gy γ-ray irradiation of IECs results in epithelium recovery. Perhaps the cdk inhibitor I protein could be used to indicate the injury induced by radiation