低氧时NF-κB和P53在大鼠肺动脉平滑肌细胞增殖和凋亡中的变化

Changes of NF-κB and P53 during Hypoxic Pulmonary Arterial Smooth Muscle Cell Proliferation and Apoptosis

对培养的肺动脉平滑肌细胞 (PASMC)用免疫细胞化学、Western blot和原位末端脱氧核苷酸转移酶标记法(TUNEL)进行检测。免疫细胞化学染色发现无血清培养基 (SFM)组中 PASMC核因子 - κB(NF- κB)阳性指数明显低于低氧 48h (H48h)组 (P<0 .0 5 ) ,H48h组 P5 3阳性指数与 SFM组相比有增高趋势。增殖细胞核抗原阳性指数(PI)在 SFM组明显低于 H48h组 (P<0 .0 5 ) ,SFM组抑制性 - κBα(I- κBα)的含量是 H48h组的 2 .5倍 ,SFM组的凋亡指数 (AI)明显高于 H48h组 (P<0 .0 5 ) ;NF- κB阳性指数与 AI呈负相关 (r=- 0 .737,P<0 .0 5 )而与 PI呈正相关 (r=0 .80 2 ,P<0 .0 5 )。提示 :低氧时 PASMC中 NF- κB活性明显增加 ,表明 NF- κB可能抑制 PASMC的凋亡并促进其增殖 ;低氧时 P5 3有增高的趋势 ,其对 PASMC增殖和凋亡的影响可能被激活的 NF- κB抑制。

To explore the changes of NF-κB and P53 during hypoxic pulmonary arterial smooth muscle cell (PASMC) proliferation and apoptosis, immunohistochemistry (IHC), Western blot and TUNEL were used to detect the cultured PASMCs. IHC staining showed that the positive index of NF-κB in serum-free medium (SFM) group was less than that in hypoxic 48 h (H48h) group (P<0.05). The positive index of P53 in SFM group was less than that in H48h group but without significant difference. Proliferative cell nuclear antigen (PCNA) index (PI) in SFM group was less than that in H48h group (P<0.05). The amount of I-κBa in SFM group was 2.5 times that of H48h group (P<0.05), apoptosis index (AI) in SFM group was higher than in H48h group (P<0.05). A negative correlation was found between the positive index of NF-κB and AI (r=-0.737, P<0.05) and a positive correlation between the positive index of NF-κB and PI (r=0.802, P<0.05). The results suggested that activity of NF-κB was significantly increased in hypoxic PASMC and might inhibit PASMC apoptosis and promote its proliferation. The amount of P53 had an increasing tendency after exposure to hypoxia and effects of P53 on PASMC proliferation and apoptosis were probably inhibited by the activated NF-κB.