Z-IETD-FMK

Z-IETD-FMK是caspase 8抑制剂。

生物活性

Z-IETD-FMK (Z-IE(OMe)TD(OMe)-FMK) is a selective and cell permeable caspase-8 inhibitor. Z-IETD-FMK is also a granzyme B inhibitor.[1-5]

In Vitro

Z-IETD-FMK 仅完全抑制 TNFα 的促凋亡作用，IC50 为 0.46 μM[1]。Z-IETD-FMK 和 Z-VAD-FMK 具有免疫抑制作用，可抑制有丝分裂原和 IL-2 诱导的人 T 细胞增殖。它们可阻断活化的原代 T 细胞中的 NF-κB，但对 T 细胞活化过程中 IL-2 和 IFN-γ 的分泌几乎没有抑制作用[2]。Z-IETD-FMK 抑制 caspase-8 的切割，仅部分抑制 caspase-3 和 PARP 的切割。Z-IETD-FMK 可阻止暴露于不同凋亡刺激物的视网膜细胞发生凋亡[3]。

In Vivo

z-IETD-FMK 对 caspase-8 的药理学抑制可显著减少肿瘤生长，这与促炎细胞因子 IL-6、TNF-α、IL-18、IL-1α、IL 的释放减少密切相关-33，但不是 IL-1β。此外，抑制 caspase-8 会减少先天抑制细胞 (例如髓源性抑制细胞) 的募集，但不会减少调节性 T 细胞向荷瘤小鼠肺部的募集[4]。

细胞实验

T cell proliferation following mitogen stimulation is determined using [3H]-thymidine incorporation. In brief， PBMCs or purified T cells are seeded at 1×106 cells/mL in 96 well plates and stimulated with either PHA (5 μg/mL or co-stimulated with anti-CD3 mAb (5 μg/mL) and anti-CD28 mAb (2.5 μg/mL) in the presence or absence of caspase inhibitor Z-IETD-FMK. The cells are cultured for 72 h with the last 16 h pulsed with [[3H]-labelled methyl-thymidine (0.037 MBq) prior to harvest onto glass fibre filter mats using a Tomtec automated multi-well harvester[2].

动物实验

Mice: Mice are divided into three groups: (1) naive， non-treated， mice; (2) CTR (control)， i.t. instilled with NMU; and (3) lung cancer-bearing mice treated with Z-IETD-FMK (0.5?μg per mouse). The involvement of caspase-8 in lung cancer development is the determined at different time points (3， 7 and 28 days)[4].

数据来源文献

[1]. Cowburn AS， et al. z-VAD-fmk augmentation of TNF alpha-stimulated neutrophil apoptosis is compound specific and does not involve the generation of reactive oxygen species.
[2]. Lawrence CP， et al. Suppression of human T cell proliferation by the caspase inhibitors， z-VAD-FMK and z-IETD-FMK is independent of their caspase inhibition properties. Toxicol Appl Pharmacol. 2012 Nov 15;265(1):103-12.
[3]. Tezel G， et al. Inhibition of caspase activity in retinal cell apoptosis induced by various stimuli in vitro. Invest Ophthalmol Vis Sci. 1999 Oct;40(11):2660-7.
[4]. Terlizzi M， et al. Pharmacological inhibition of caspase-8 limits lung tumour outgrowth. Br J Pharmacol. 2015 Aug;172(15):3917-28.
[5]. Yang J， et al. Granzyme B?Is an?Essential?Mediator?in CD8+?T Cell?Killing?of?Theileria?parva-Infected?Cells.Infect Immun.?2018 Dec 19;87(1). pii: e00386-18.