Endonuclease G mediates endothelial cell death induced by carbamylated LDL
Endonuclease G mediates endothelial cell death induced by carbamylated LDL
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DOI：
10.1152/ajpheart.01311.2010
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发表时间：
2011-06-01
影响因子：
4.8
通讯作者：
Shah, Sudhir V.
中科院分区：
文献类型：
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作者：
Apostolov, Eugene O.;Ray, Debarti;Shah, Sudhir V.
Apostolov EO，Ray D，Alobuia WM，Mikhailova MV，Wang X，Basnakian AG，Shah SV.核酸内切酶G介导氨甲酰化LDL诱导的内皮细胞死亡。Am J Physiol Heart Circ Physiol 300：H1997-H2004，2011.首次发表于2011年4月1日; doi：10.1152/ajpheart.01311.2010.-终末期肾病是慢性肾病的终末期，与心血管疾病的高发病率相关。心血管疾病通常由氨甲酰化LDL（cLDL）引起的内皮损伤引起，cLDL是脲衍生氰酸酯修饰LDL的产物。我们以前的数据表明，cLDL诱导丝裂原活化蛋白激酶依赖的有丝分裂DNA片段和细胞死亡。然而，该途径的机制尚不清楚。目前的研究表明，cLDL诱导的内皮有丝分裂细胞死亡是独立的caspase-3。核酸内切酶G（EndoG）的表达，参与半胱天冬酶非依赖性DNA片段化的核酸酶，显着增加cLDL暴露于细胞。通过RNA干扰抑制EndoG可以保护cLDL诱导的DNA片段化，而EndoG的过表达则会诱导内皮细胞中更多的DNA片段化。用从野生型（WT）和EndoG敲除（KO）小鼠分离的原代内皮细胞进行的离体实验证明，与WT细胞相比，EndoG KO细胞被部分保护免受cLDL毒性。为了确定cLDL的体内毒性，我们将cLDL或天然LDL（nLDL）静脉内给予WT和EndoG KO小鼠，然后使用流式细胞术测量血液中的漂浮内皮细胞。结果显示，WT小鼠中cLDL与nLDL注射后漂浮内皮细胞数量增加，但EndoG KO小鼠中未出现。最后，MEK-ERK 1/2和JNK-c-jun通路的抑制剂降低cLDL诱导的EndoG过表达和DNA片段化。总之，我们的数据表明，cLDL诱导的内皮细胞毒性是半胱天冬酶独立的，由EndoG依赖性DNA片段化引起。
Apostolov EO, Ray D, Alobuia WM, Mikhailova MV, Wang X, Basnakian AG, Shah SV. Endonuclease G mediates endothelial cell death induced by carbamylated LDL. Am J Physiol Heart Circ Physiol 300: H1997-H2004, 2011. First published April 1, 2011; doi: 10.1152/ajpheart.01311.2010.-End-stage kidney disease is a terminal stage of chronic kidney disease, which is associated with a high incidence of cardiovascular disease. Cardiovascular disease frequently results from endothelial injury caused by carbamylated LDL (cLDL), the product of LDL modification by urea-derived cyanate. Our previous data suggested that cLDL induces mitogen-activated protein kinase-dependent mitotic DNA fragmentation and cell death. However, the mechanism of this pathway is unknown. The current study demonstrated that cLDL-induced endothelial mitotic cell death is independent of caspase-3. The expression of endonuclease G (EndoG), the nuclease implicated in caspase-independent DNA fragmentation, was significantly increased in response to cLDL exposure to the cells. The inhibition of EndoG by RNAi protected cLDL-induced DNA fragmentation, whereas the overexpression of EndoG induced more DNA fragmentation in endothelial cells. Ex vivo experiments with primary endothelial cells isolated from wild-type (WT) and EndoG knockout (KO) mice demonstrated that EndoG KO cells are partially protected against cLDL toxicity compared with WT cells. To determine cLDL toxicity in vivo, we administered cLDL or native LDL (nLDL) intravenously to the WT and EndoG KO mice and then measured floating endothelial cells in blood using flow cytometry. The results showed an increased number of floating endothelial cells after cLDL versus nLDL injection in WT mice but not in EndoG KO mice. Finally, the inhibitors of MEK-ERK1/2 and JNK-c-jun pathways decreased cLDL-induced EndoG overexpression and DNA fragmentation. In summary, our data suggest that cLDL-induced endothelial toxicity is caspase independent and results from EndoG-dependent DNA fragmentation.