Z-IETD-FMK

Z-IETD-FMK (Z-IE(OMe)TD(OMe)-FMK) is a cell-permeable, irreversible inhibitor specific for caspase-8. Z-IETD-FMK also an inhibitor of granzyme B. Z-IETD-FMK exhibits cell permeability. Z-IETD-FMK can be used in studies of the extrinsic apoptosis pathway, pyroptosis, and programmed necrosis.

Methods: Human PBMCs, purified CD4⁺ and CD8⁺ T cells were treated with mitogens (PHA 5 μg/mL) and Z-IETD-FMK (25, 50, 100 μM) for 72 hours. DNA synthesis was detected using the [³H]-thymidine incorporation assay. Cell division was assessed by CFSE dilution flow cytometry.
Results: Z-IETD-FMK significantly inhibited T cell proliferation at 100 μM. [1]
Methods: Mouse bone marrow-derived neutrophils were treated with 50 μM Z-IETD-FMK for 24 hours (ELISA); 6–8 hours (qPCR). ELISA measured CXCL1 and IL-1β levels in culture supernatants; qRT-PCR detected IL-1β and TNF-α mRNA.
Results: Z-IETD-FMK significantly induced neutrophil production of CXCL1 and IL-1β and upregulated their mRNA. [2]

Methods: C57BL/6 mice were nasally infected with Streptococcus pneumoniae D39 or carbapenem-resistant Klebsiella pneumoniae. Intravenous administration of Z-IETD-fmk (6 mg/kg) was initiated 24 hours post-infection, administered once daily for 5 consecutive days.
Results: Z-IETD-fmk treatment significantly improved survival rates (Streptococcus pneumoniae: control group 38% vs. treatment group 88%) and markedly reduced intrapulmonary bacterial load. [2]
Methods: Adult male SD rats underwent SAH modeling via intravascular perforation. Z-IETD-FMK (1 mg/kg) was administered via tail vein injection starting 21 days post-SAH and continued until day 27.
Results: The Z-IETD-FMK treatment group showed significant improvement in impaired spatial learning and memory abilities, as well as reduced motor coordination, indicating its protective effect on long-term neurological function. [3]

Proteasome assay: Exponentially growing cells on a 96-well clustered plate are treated with different concentrations of drugs or left untreated (control) for 6 hours. Proteasomes extracted with 0.5% NP40 buffer are mixed with equal amounts of samples in 100 μL total volume, and then incubated with 25 μmol/L of fluorogenic substrates (LRR- specific for trypsin-like activity, LLE-specific for caspase-like activity, and SUVY-specific for chymotrypsin-like activity) in black-bottom 96-well plates at 37°C. Fluorescence is monitored every 5 minutes at the wavelength of 360 nm (excitation) and 480 nm (emission).

Ethanol: < 1 mg/mL (insoluble or slightly soluble)

H2O: < 1 mg/mL (insoluble or slightly soluble)

DMSO: 240 mg/mL (366.59 mM), Sonication is recommended.

10% DMSO+40% PEG300+5% Tween 80+45% Saline: 5 mg/mL (7.64 mM), Sonication is recommended.