Sonoki K, Iwase M, Sasaki N, Ohdo S, Higuchi S, Takata Y, Iida M
Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Br J Pharmacol. 2008 Apr;153(7):1399-408. doi: 10.1038/bjp.2008.12. Epub 2008 Feb 11.
Secretory phospholipase A2 (sPLA2) is implicated in atherosclerosis, although the effects of specific sPLA2 inhibitors have not been studied. We investigated the effects of the indole analogue indoxam on low-density lipoprotein (LDL) modification by sPLA2 enzymes of different types and on the associated inflammatory responses in human umbilical vein endothelial cells (HUVEC).
LDL modification was assessed by measuring the contents of two major molecular species of lysophosphatidylcholine (LPC) using electrospray ionization-liquid chromatography/mass spectrometry. The proinflammatory activity of the modified LDL was evaluated by determining monocyte chemoattractant protein-1 (MCP-1) mRNA expression and transcriptional factor nuclear factor-kappaB (NF-kappaB) activity in HUVEC.
Indoxam dose-dependently inhibited palmitoyl- and stearoyl-LPC production in LDL incubated with snake venom sPLA2 (IC50 1.2 microM for palmitoyl-LPC, 0.8 microM for stearoyl-LPC). MCP-1 mRNA expression and NF-kappaB activity were enhanced by venom sPLA2-treated LDL, which was completely suppressed by indoxam but not by thioetheramide-PC, a competitive sPLA2 inhibitor. Indoxam also suppressed LPC production in LDL treated with human synovial type IIA sPLA2. Tumour necrosis factor alpha (TNFalpha) increased type V sPLA2 expression in HUVEC. Indoxam dose-dependently suppressed LPC production in native and glycoxidized LDL treated with TNFalpha-stimulated HUVEC. Indoxam suppressed MCP-1 mRNA expression and NF-kappaB activity in TNFalpha-stimulated HUVEC incubated with native or glycoxidized LDL.
Indoxam prevented sPLA2-induced LPC production in native and glycoxidized LDL as well as LDL-induced inflammatory activity in HUVEC. Our results suggest that indoxam may be a potentially useful anti-atherogenic agent.
分泌型磷脂酶A2（sPLA2）与动脉粥样硬化有关，尽管尚未对特定sPLA2抑制剂的作用进行研究。我们研究了吲哚类似物吲哚昔康对不同类型sPLA2酶介导的低密度脂蛋白（LDL）修饰以及对人脐静脉内皮细胞（HUVEC）中相关炎症反应的影响。
通过电喷雾电离-液相色谱/质谱法测量溶血磷脂酰胆碱（LPC）的两种主要分子种类的含量来评估LDL修饰。通过测定HUVEC中单核细胞趋化蛋白-1（MCP-1）mRNA表达和转录因子核因子-κB（NF-κB）活性来评估修饰后LDL的促炎活性。
吲哚昔康剂量依赖性地抑制了与蛇毒sPLA2共同孵育的LDL中棕榈酰-LPC和硬脂酰-LPC的产生（棕榈酰-LPC的IC50为1.2μM，硬脂酰-LPC的IC50为0.8μM）。毒液sPLA2处理的LDL可增强MCP-1 mRNA表达和NF-κB活性，吲哚昔康可完全抑制该作用，但竞争性sPLA2抑制剂硫醚酰胺-PC则无此作用。吲哚昔康还可抑制人滑膜IIA型sPLA2处理的LDL中的LPC产生。肿瘤坏死因子α（TNFα）可增加HUVEC中V型sPLA2的表达。吲哚昔康剂量依赖性地抑制了经TNFα刺激的HUVEC处理的天然和糖氧化LDL中的LPC产生。吲哚昔康可抑制与天然或糖氧化LDL共同孵育的TNFα刺激的HUVEC中的MCP-1 mRNA表达和NF-κB活性。
吲哚昔康可防止sPLA2诱导的天然和糖氧化LDL中的LPC产生以及LDL诱导的HUVEC中的炎症活性。我们的结果表明吲哚昔康可能是一种潜在有用的抗动脉粥样硬化药物。
