Z-VAD-FMK

Z-VAD-FMK (Benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethylketone), an ICE-like protease inhibitor, inhibits apoptosis by preventing the processing of CPP32 to its active form. [3]

Z-VAD-FMK is immunosuppressive in vitro and inhibit T cell proliferation without blocking the processing of caspase-8 and caspase-3. Z-VAD-FMK is capable of inhibiting T cell proliferation induced by anti-CD3 plus anti-CD28 or PHA. Besides, z-VAD-FMK inhibits caspase processing during apoptosis but not during T cell activation. Z-VAD-FMK Inhibits caspase processing and apoptosis induction in tumor cells in vitro (IC₅₀ = 0.0015 - 5.8 mM). [1]

Z-VAD-FMK, can be used to induce necroptosis under certain stimuli. Treatment of mice with Z-VAD-FMK could significantly reduce mortality and alleviate disease after lipopolysaccharide (LPS) challenge. Notably, in LPS-challenged mice, treatment with Z-VAD-FMK could also reduce the percentage of peritoneal macrophages by promoting necroptosis and inhibiting pro-inflammatory responses in macrophages. What’s more, pretreatment with Z-VAD-FMK promoted LPS-induced nitric oxide-mediated necroptosis of bone marrow-derived macrophages (BMDMs), leading to reduced pro-inflammatory cytokine secretion. Interestingly, Z-VAD-FMK treatment promoted the accumulation of myeloid-derived suppressor cells (MDSCs) in a mouse model of endotoxin shock, and this process inhibited LPS-induced pro-inflammatory responses in macrophages. Treatment with Z-VAD-FMK alleviates LPS-induced endotoxic shock by inducing macrophage necroptosis and promoting MDSC-mediated inhibition of macrophage activation. For in vivo experienment, the mice were pretreated or post-treated with Z-VAD-FMK (5, 10, and 20 μg/g of body weight) or vehicle (saline) for 2 h and endotoxic shock was induced by an intraperitoneal injection of LPS (10 μg/g of body weight) and saline was used as control. [2]

References:
[1]. Lawrence CP, Chow SC. 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.
[2]. Li X, Yao X, Zhu Y, et al. The Caspase Inhibitor Z-VAD-FMK Alleviates Endotoxic Shock via Inducing Macrophages Necroptosis and Promoting MDSCs-Mediated Inhibition of Macrophages Activation. Front Immunol. 2019 Aug 2;10:1824.
[3]. Slee EA, Zhu H, et al. Benzyloxycarbonyl-Val-Ala-Asp (OMe) fluoromethylketone (Z-VAD.FMK) inhibits apoptosis by blocking the processing of CPP32. Biochem J. 1996 Apr 1;315 (Pt 1) (Pt 1):21-4.

Z-VAD-FMK（苄氧羰基-Val-Ala-Asp（OMe）氟甲基酮），是一种类似ICE的蛋白酶抑制剂，通过阻止CPP32转化为其活性形式来抑制细胞凋亡。[3]

Z-VAD-FMK是一种体外免疫抑制剂，可以抑制T细胞增殖，但不会阻止caspase-8和caspase-3的处理。 Z-VAD-FMK能够抑制由anti-CD3加anti-CD28或PHA诱导的T细胞增殖。此外，z-VAD-FMK在凋亡期间可以抑制caspase的处理，但在T细胞激活期间则不能。 Z-VAD-FMK还能够体外抑制肿瘤细胞中caspase的处理和凋亡诱导（IC50 = 0.0015 - 5.8 mM）。[1]

Z-VAD-FMK可以在某些刺激下诱导坏死程序性细胞死亡。用Z-VAD-FMK治疗小鼠可显著降低脂多糖（LPS）挑战后的死亡率和缓解疾病。值得注意的是，在LPS挑战的小鼠中，使用Z-VAD-FMK治疗还可以通过促进坏死程序性细胞死亡并抑制巨噬细胞中的促炎反应来减少腹腔巨噬细胞的百分比。此外，预处理Z-VAD-FMK可促进LPS诱导一氧化氮介导的骨髓源性巨噬细胞（BMDMs）坏死程序性细胞死亡，从而减少促炎因子分泌。有趣的是，在内毒素休克小鼠模型中，Z-VAD-FMK处理促进了造血来源抑制性细胞（MDSCs）积累，并且这个过程抑制了LPS诱导巨噬细胞产生促炎反应。使用Z-VAD-FMK治疗通过诱导巨噬细胞坏死程序性细胞死亡和促进MDSC介导的巨噬细胞活化抑制来缓解LPS诱导的内毒素休克。在体内实验中，小鼠预处理或后处理Z-VAD-FMK（5、10和20μg/g体重）或载体（生理盐水）2小时，并通过腹腔注射LPS（10μg/g体重）诱导内毒素休克，使用生理盐水作为对照组。[2]