溶血卵磷脂对人内皮细胞CD73的调节与PKC的关系

目的：探讨溶血卵磷脂（LPC）对人脐静脉内皮细胞（HUVEC）胞外5’-核苷酸酶（CD73）的调节作用及其与蛋白激酶C（PKC）的关系。方法：将含已融合HUVEC的细胞培养皿分为4组（n=15）：①LPC组：培养皿中加入LPC10μmol/L;②CHE（白屈菜赤碱,PKC抑制剂）组：加入CHE100μmol/L及LPC10μmol/L;③AOPCP（α,β-甲基腺苷-5′-二磷酸,CD73抑制剂）组：加入AOPCP50μmol/L及LPC10μmol/L;④对照组：无干预。每组均于实验开始时加入乙烯-单磷酸腺苷（eAMP,5μmol/L）。在实验第15、30、45min测定各培养皿中乙烯-腺苷（eAD）含量。结果：在上述三个时间点LPC组HUVEC的eAD生成均较对照组显著增高（P〈0.05）,加入CHE使LPC的这种增加作用消失,其eAD生成与对照组无差别（P〉0.05）,而AOPCP组eAD生成较其它三组均显著减少（P〈0.01）。结论：LPC可兴奋内皮细胞胞外CD73,此作用可被PKC抑制剂CHE抑制,LPC上调CD73活性作用可能与PKC有关。

Role of PKC in regulation of CD73 by lysophosphatidylcholine in human endothelial cells

Objective：To discuss the effect of protein kinase C （PKC） on regulation of ecto-5＇-nucleotidase activity by lysophosphatidylcholine（LPC） in human umbilical endothelial cells （HUVEC）.Methods：Experiments were conducted in HUVEC grown on dishes which were divided into 4 groups （n=15）：①Control group in which only eAMP（5 μmol/L） was added;②LPC group in which HUVEC were incubated with LPC（10μmol/L） before eAMP was added;③Chelerythrine group in which cells were pre-incubated with the PKC inhibitor chelerythrine（100μmol/L） before LPC and eAMP were added;④α,β-Methyladenosine-5＇-Diphosphate（AOPCP） group in which cells were incubated with AOPCP （10μmol/L） before eAMP was added.Etheno-adenosine production was detected at 15th,30th,45th min with high performance liquid chromatography（HPLC） respectively.Results：Comparing to the control group LPC significantly increased etheno-adenosine production at three time points respectively（P〈0.05）.Furthermore,PKC inhibitor chelerythrine abolished this effect of LPC and the etheno-adenosine production at three time points were at the same level of control group （P〉0.05）.CD73 inhibitor AOPCP significantly decreased the etheno-adenosine production compared to the other three groups（P〈0.01）.Conclusion：Ecto-5＇-nucleotidase can be modulated within minutes following exposure of HUVEC to LPC and this response may be mediated by PKC in HUVEC.