Department of Pharmacology, College of Pharmacy & Pharmaceutical Sciences, The University of Toledo, Health Science Campus, Toledo, OH 43614, USA.
Toxicol Appl Pharmacol. 2013 Jul 15;270(2):87-96. doi: 10.1016/j.taap.2013.04.014. Epub 2013 Apr 28.
In the present study, we evaluated the effect of largazole (LAR), a marine-derived class I HDAC inhibitor, on tumor necrosis factor-α (TNF-α)-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and matrix metalloproteinase-2 (MMP-2) activity. LAR (1-5 μM) had no adverse effect on the viability of RA synovial fibroblasts. Among the different class I HDACs screened, LAR (0.5-5 μM) inhibited the constitutive expression of HDAC1 (0-30%). Surprisingly, LAR increased class II HDAC [HDAC6] by ~220% with a concomitant decrease in HDAC5 [30-58%] expression in RA synovial fibroblasts. SAHA (5 μM), a pan-HDAC inhibitor, also induced HDAC6 expression in RA synovial fibroblasts. Pretreatment of RA synovial fibroblasts with LAR further enhanced TNF-α-induced ICAM-1 and VCAM-1 expression. However, LAR inhibited TNF-α-induced MMP-2 activity in RA synovial fibroblasts by 35% when compared to the TNF-α-treated group. Further, the addition of HDAC6 specific inhibitor Tubastatin A with LAR suppressed TNF-α+LAR-induced ICAM-1 and VCAM-1 expression and completely blocked MMP-2 activity, suggesting a role of HDAC6 in LAR-induced ICAM-1 and VCAM-1 expression. LAR also enhanced TNF-α-induced phospho-p38 and phospho-AKT expression, but inhibited the expression of phospho-JNK and nuclear translocation of NF-κBp65 in RA synovial fibroblasts. These results suggest that LAR activates p38 and Akt pathways and influences class II HDACs, in particular HDAC6, to enhance some of the detrimental effects of TNF-α in RA synovial fibroblasts. Understanding the exact role of different HDAC isoenzymes in RA pathogenesis is extremely important in order to develop highly effective HDAC inhibitors for the treatment of RA.
在本研究中，我们评估了海洋来源的 I 类组蛋白去乙酰化酶抑制剂 largazole（LAR）对肿瘤坏死因子-α（TNF-α）诱导的细胞间黏附分子-1（ICAM-1）和血管细胞黏附分子-1（VCAM-1）表达以及基质金属蛋白酶-2（MMP-2）活性的影响。LAR（1-5 μM）对 RA 滑膜成纤维细胞的活力没有不良影响。在筛选的不同 I 类组蛋白去乙酰化酶中，LAR（0.5-5 μM）抑制了组蛋白去乙酰化酶 1（HDAC1）的组成型表达（0-30%）。令人惊讶的是，LAR 使 RA 滑膜成纤维细胞中的 II 类组蛋白去乙酰化酶[HDAC6]增加了约 220%，同时使 HDAC5[30-58%]的表达降低。pan-HDAC 抑制剂 SAHA（5 μM）也诱导 RA 滑膜成纤维细胞中 HDAC6 的表达。LAR 预处理进一步增强了 TNF-α诱导的 ICAM-1 和 VCAM-1 的表达。然而，与 TNF-α处理组相比，LAR 抑制了 RA 滑膜成纤维细胞中 TNF-α诱导的 MMP-2 活性达 35%。此外，用 HDAC6 特异性抑制剂 Tubastatin A 与 LAR 共同处理可抑制 TNF-α+LAR 诱导的 ICAM-1 和 VCAM-1 的表达，并完全阻断 MMP-2 的活性，表明 HDAC6 在 LAR 诱导的 ICAM-1 和 VCAM-1 表达中发挥作用。LAR 还增强了 TNF-α诱导的磷酸化 p38 和磷酸化 AKT 的表达，但抑制了磷酸化 JNK 的表达和 NF-κBp65 的核转位。这些结果表明，LAR 激活了 p38 和 Akt 途径，并影响 II 类组蛋白去乙酰化酶，特别是 HDAC6，以增强 TNF-α在 RA 滑膜成纤维细胞中的一些有害作用。了解不同组蛋白去乙酰化酶同工酶在 RA 发病机制中的确切作用对于开发高效的 RA 治疗用组蛋白去乙酰化酶抑制剂非常重要。
