| 摘要: |
| 目的：研究低氧对近端肾小管细胞株(LLC-PK1)细胞增殖和去分化的作用。方法：LLC-PK1细胞分别置于低氧（3％ O2）和正常氧（18％ O2）孵箱中培养，用3H-胸腺嘧啶掺入法和细胞计数，观察细胞增殖情况；以钠依赖葡萄糖和氨基异丁酸(AIB)转运为指标，观察细胞分化程度；用放射核素法测定蛋白激酶C(PKC)活性。结果：与正常氧培养比较，低氧培养16 h，3H-胸腺嘧啶掺入显著增加；培养24 h，细胞数显著增加；培养72 h，细胞摄取α-甲基糖甙和AIB显著降低。细胞低氧培养4 h，细胞膜与细胞质PKC活性比率增高，随后降至原先水平；但继续培养至24 h，PKC活性再次增高，直至72 h，表明PKC呈急性和持续双相激活。PKC抑制剂可显著抑制低氧诱导的3H-胸腺嘧啶掺入，并显著增加α-甲基糖甙和AIB转运。结论：慢性低氧可诱导LLC-PK1细胞的增殖和去分化，这些作用部分由PKC持续激活介导。 |
| 关键词: 低氧 LLC-PK1细胞 增殖 分化 |
| DOI： |
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| Effect of chronic hypoxia on proliferation and dedifferentiation of LLC-PK1 cells |
| 宋吉,陈蕾,梅长林 |
| () |
| Abstract: |
| Objective: To explore the effect of chronic hypoxia on the proliferation and dedifferentiation of LLC-PK1 cells. Methods: The cells were either exposed to hypoxia(3%O2) or maintained in normoxia(18%O2) followed by the assessment of ［3H］-thymidine incorporation and cell number as indices of cellular proliferation and sodium-dependent transport of glucose and a minoisobutyric acid(AIB) as indices of differentiation. The activity of protein kinase C(PKC) was determined with radionuclear technique. Results: Exposure of quiescent cultures to hypoxia for 16 h resulted in a significant increase in ［3H］-thymidine followed by a significant increase in cell number at 24 h in comparison with respective normoxic controls. Confluent cultures exposed to 72 h of hypoxia exhibited significant inhibition of α-methyl glucose and AIB uptakes when compared with their respective normoxic counterparts. Hypoxia also activated PKC at 4 h followed by a subsequent return to baseline with reactivation at 24 h which remained sustained up to 72 h, suggesting a biphasic acute and sustained activation of PKC. Furthermore, the hypoxia-induced alterations in ［3H］-thymidine incorporation as well as α-methyl glucose and AIB transport activities were mitigated by inhibitors of PKC. Conclusion: Chronic hypoxia induces both proliferation and dedifferentiation of LLC-PK1 cells mediated, in part, by the sustained activation of PKC. |
| Key words: anoxia LLC-PK1 cells proliferation differentiation |
