Regulation of Tumor Necrosis Factor-Like Weak Inducer of Apoptosis Receptor Protein (TWEAKR) Expression by Kaposi's Sarcoma-Associated Herpesvirus MicroRNA Prevents TWEAK-Induced Apoptosis and Inflammatory Cytokine Expression
Regulation of Tumor Necrosis Factor-Like Weak Inducer of Apoptosis Receptor Protein (TWEAKR) Expression by Kaposi's Sarcoma-Associated Herpesvirus MicroRNA Prevents TWEAK-Induced Apoptosis and Inflammatory Cytokine Expression
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DOI：
10.1128/jvi.00884-10
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发表时间：
2010-12-01
影响因子：
5.4
通讯作者：
Ziegelbauer, Joseph M.
中科院分区：
文献类型：
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作者：
Abend, Johanna R.;Uldrick, Thomas;Ziegelbauer, Joseph M.
卡波西肉瘤（KS）相关疱疹病毒（KSHV）是KS的病原体，KS是第二种最常见的艾滋病相关恶性肿瘤。KSHV在潜伏期期间表达至少18种不同的成熟microRNA（miRNAs）。为了鉴定KSHV miRNAs的细胞靶点，我们分析了先前报道的一系列微阵列，研究了KSHV miRNAs存在时细胞基因表达的变化。肿瘤坏死因子（TNF）样弱凋亡诱导因子（TWEAK）受体（TWEAKR）是在KSHV miR-K12-10a（miR-K10 a）存在下最一致和稳健下调的基因之一。用含有TWEAKR的3'非翻译区（UTR）的报告质粒进行的荧光素酶测定的结果表明miR-KlOa靶向TWEAKR。TWEAKR的3' UTR内的两个预测的miR-KlOa识别位点的突变完全破坏了miR-KlOa的抑制。在用miR-K10 a转染的细胞中以及在从头KSHV感染期间，TWEAKR的表达下调。在KS肿瘤来源的内皮细胞系中，miR-K10 a下调TWEAKR导致TWEAK诱导的caspase活化水平降低。此外，通过膜联蛋白V染色和末端脱氧核苷酸转移酶介导的dUTP-生物素缺口末端标记（TUNEL）测定，用miR-K10 a转染的细胞显示较少的凋亡诱导。最后，在原代人内皮细胞中，miR-K10 a下调TWEAKR导致响应于TWEAK的促炎细胞因子白细胞介素-8（IL-8）和单核细胞趋化蛋白1（MCP-1）的表达水平降低。这些结果鉴定并验证了KSHV miRNAs的重要细胞靶点。此外，我们证明了病毒miRNA保护细胞免于凋亡并抑制促炎反应，这可能在KS病变的复杂背景下具有重要意义。
Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is the causative agent of KS, the second most common AIDS-associated malignancy. KSHV expresses at least 18 different mature microRNAs (miRNAs) during latency. To identify cellular targets of KSHV miRNAs, we have analyzed a previously reported series of microarrays examining changes in cellular gene expression in the presence of KSHV miRNAs. Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) receptor (TWEAKR) was among the most consistently and robustly downregulated genes in the presence of KSHV miR-K12-10a (miR-K10a). Results from luciferase assays with reporter plasmids containing the 3' untranslated region (UTR) of TWEAKR suggest a targeting of TWEAKR by miR-K10a. The mutation of two predicted miR-K10a recognition sites within the 3' UTR of TWEAKR completely disrupts inhibition by miR-K10a. The expression of TWEAKR was downregulated in cells transfected with miR-K10a as well as during de novo KSHV infection. In a KS tumor-derived endothelial cell line, the downregulation of TWEAKR by miR-K10a resulted in reduced levels of TWEAK-induced caspase activation. In addition, cells transfected with miR-K10a showed less induction of apoptosis by annexin V staining and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays. Finally, the downregulation of TWEAKR by miR-K10a in primary human endothelial cells resulted in a decrease in levels of expression of the proinflammatory cytokines interleukin-8 (IL-8) and monocyte chemoattractant protein 1 (MCP-1) in response to TWEAK. These results identify and validate an important cellular target of KSHV miRNAs. Furthermore, we demonstrate that a viral miRNA protects cells from apoptosis and suppresses a proinflammatory response, which may have significant implications in the complex context of KS lesions.