Studies on relation between thymocytes differentiation and gene expression related to Notch signal transduction pathway in senescence-accelerated mice / 中国免疫学杂志

ABSTRACT

Objective:To research the age-related changes of thymocyte subsets and Notch 1,Presenilin 1,Presenilin 2,HES1 mRNA expression in senescence-accelerated mice during aging,and analyze the relation of the two changes.Methods:Thymocyte subsets were assayed by flow cytometry,the expression of Notch 1,Presenilin 1,Presenilin 2,HES1 mRNA was detected by quantitative real-time PCR fluorescence assay.Results:The rate of CD4+CD8+ double-positive(DP) cell of thymocytes was fairly high in first-and second-week-old SAM,and began to decrease at four-week-old,but no significant difference was observed between SAMP8 and SAMR1 of the same age.The rate of CD4+CD8-single-positive(SP) cell of thymocytes in SAM was age-related increased,yet no significant difference was overserved between SAMP8 and SAMR1,except that it was much lower at the eighth week in SAMP8 than in SAMR1.The rate of CD4-CD8+ SP cell of thymocytes in SAM was also age-related increased,but it was obviously higher in SAMP8 than in SAMR1 after the fourth week.The expression of Notch 1,Presenilin 2 and HES1 gene is age-related increased.The Notch 1 gene was higher at each week in SAMP8 than in SAMR1,but presenilin 2 and HES1 were observed higher in SAMP8 than in SAMR1 only after the fourth week.On the contrary,Presenilin 1 gene was age-related decreased,and it was lower in SAMP8 than in SAMR1 after the fourth week.Conclusion:It suggestes that the expression level of Notch 1,Presenilin 2 and HES1 gene positively correlated with the differentiation of CD4-CD8+ SP thymocyte,while presenilin 1 gene evidenced a significant negative correlated with it.