Characterization of cell growth and apoptosis in cell cycle analysis induced by butyric acid

(1)用丁酸处理Jurkat细胞的流式细胞分析显示，细胞在细胞周期的G1/S界面呈剂量依赖性阻断。特别是，2.5 mM丁酸处理21 h，导致G1相阻滞。这些结果表明，丁酸阻断了细胞从G1期到S期的转变，从而不可逆地阻止了Jurkat细胞向有丝分裂的进程。(2)通过WB分析分析丁酸对Jurkat细胞周期进程的影响。大剂量丁酸抑制细胞周期蛋白D3的表达，作用于G1期初期。然而，Cyclin D1、D2、Cdk4和Cdk6的表达没有变化。而丁酸则抑制G1期到S期的Cyclin A和E的表达。丁酸还能抑制细胞周期蛋白A和e依赖性激酶cdk2的表达。高剂量丁酸使p21 ~ <CIP1/WAF1>的表达增加，而p21 ~ <CIP1/WAF1>是Cyclin-Cdk复合物的抑制剂。丁酸还能抑制G2期向M期过渡时激活的Cyclin A和E的表达，但不影响Cyclin A和E依赖性激酶Cdc 2的表达。(3)为了研究丁酸敏化下游激活的转录途径，利用cDNA芯片监测丁酸处理Jurkat细胞后的转录变化。丁酸处理主要导致Bax、Bad、Bak、Caspase-3、-6、-7、-8、-9等促凋亡基因的表达增加，而Bcl-2、谷氨酸等抗凋亡介质的表达降低。ERK的抑制和JNK的诱导也被观察到。因此，利用cDNA阵列技术证实了丁酸处理Jurkat细胞的表达谱。这些结果表明，丁酸诱导的T细胞凋亡通过增加p21 ~ <CIP1/WAF1>的表达，随后降低Cdk2-Cyclin E和Cdk2-Cyclin a参与细胞周期阻滞

(1) Flow cytometric analysis of Jurkat cells treated with butyric acid revealed that the cells were blocked at the G1/S interface of the cell cycle in dose-dependent fashion. Especially, 21 h treatment with 2.5 mM butyric acid caused the G1 phase arrest. These results suggest that butyric acid blocks transition of the cells from G1 to the S phase of cell cycle and the thereby irreversibly halts the progression of Jurkat cells to mitosis.(2) We analyzed the effect of butyric acid on cell cycle progression in Jurkat cells by WB analysis. High dose of butyric acid depressed the expression of Cyclin D3 which works in the beginning of G1 phase. However, there was no change in Cyclin D1, D2, Cdk4, and Cdk6 expression. Whereas, butyric acid depressed the expressions of Cyclin A and E which activate in transition from G1 to S phase. Butyric acid also depressed Cdk 2 expression which is Cyclin A- and E-dependent kinase. High dose of butyric acid increased the expression of p21〜<CIP1/WAF1> which … More is inhibitor of Cyclin-Cdk complex. Butyric acid also depressed the expressions of Cyclin A and E which activate in transition from G2 to M phase, however, did not effect Cdc 2 expression which is Cyclin A- and E-dependent kinase.(3) To examine the transcriptional pathways activated downstream of butyric acid-sensitization, cDNA microarrays were used to monitor transcriptional changes in Jurkat cells upon treatment with butyric acid. Butyric acid treatment primarily resulted in increased expression of proapoptotic genes such as Bax, Bad, Bak, Caspase-3, -6, -7, -8, -9, while the expression of anti-apoptotic mediators such as Bcl-2 and glutatione was decreased. A repression of ERK and an induction of JNK were also observed. Thus, the expression profile of butyric acid-treated Jurkat cells was confirmed by means of cDNA array.These results suggest that butyric acid-incudec T cell apoptosis s involved in cell cycle arrest through the increase of p21〜<CIP1/WAF1> expression followed by the decrease of Cdk2-Cyclin E and Cdk2-Cyclin A. Less