目的探讨气道上皮细胞衍生的胰岛素样生长因子(IGF1)对CD8+T细胞极化的影响。方法人气道上皮细胞株RPMI2650与鼠过敏原Der p1共培养72 h,用定量PCR及Western免疫印迹检测其IGF1表达情况。将前述上皮细胞、重组IGF1和IGF1抗体分别加入抗体激活的CD8+T细胞中培养,用流式细胞仪检测细胞凋亡。检测Der p1活化的上皮细胞及IGF1对CD8+T细胞p53基因甲基化及表达的影响。结果加入Der p1共同孵育后,RPMI2650细胞IGF1mRNA(23.1%±5.2%vs 5.2%±2.3%,P<0.01)和蛋白表达(33.4±6.4 vs 9.2±4.6,P<0.01)均明显增加。将CD3/CD28抗体激活的CD8+T细胞与Der p1活化的上皮细胞共培养,凋亡细胞增加的趋势被抑制(41.7%±8.2%vs5.2%±1.8%,P<0.01)。直接加入重组IGF1有同样效果,而IGF1抗体能阻断该效应。Der p1活化的上皮细胞能抑制活化CD8+T细胞p53基因mRNA(29.1%±5.9%vs 16.2%±4.3%,P<0.01)和蛋白表达(63.3±8.9 vs 26.9±5.6,P<0.01),加入IGF1抗体后这种作用消失。重组IGF1使CD8+T细胞p53基因甲基化增加。结论 Der p1蛋白能够诱发RPMI2650细胞产生IGF1,后者通过诱导p53基因甲基化抑制CD8+T细胞凋亡。
Intracellular calcium overload is a key factor for myocardial ischemia reperfusion injury（IR）. However, there was no report for interstitial calcium concentration dynamics. We investigated the interstitial calcium dynamics in rat myocardial IR model in vivo. A microdialysis system was involved, and the time delay of the system and recovery time was introduced and tested with a fluids switching method. Twelve SD rats were divided into IR or control group. Myocardial IR was induced by ligating（20 min） then releasing（60 min） the suture underlying left anterior descending branch. Mycrodialyisis probe was implanted into the left ventricular myocardium perfusion area for occlusion. Dialysate samples were collected every 10 min. Dialysate calcium concentration was detected with an atomic absorption spectrophotometer. Recovery time for the microdialysis system was 20 min, and recovery rate was 16%. Dialysate calcium concentration showed no changes during ischemia, descended immediately after reperfusion, reached the lowest level（67% of baseline value） 20 min after reperfusion, then escalated slowly. Recovery time was an important parameter for mycrodialysis technique, and it should not be neglected and needed to be tested. Our data suggest that interstitial calcium concentration in rats with myocardial IR in vivo kept steady in ischemia, descended rapidly at the initial reperfusion, then rebounded slowly. In conclusion, we introduced the concept of recovery time for microdialysis and provided a simple testing method.
