WR-1065, the active form of amifostine, protects HL-60 cells but not peripheral blood mononuclear cells from radiation and etoposide-induced apoptosis

Amifostine Pretreatment Attenuates Myocardial Ischemia/Reperfusion Injury by Inhibiting Apoptosis and Oxidative Stress

The present study was aimed at investigating the effect of amifostine on myocardial ischemia/reperfusion (I/R) injury of mice and H9c2 cells cultured with TBHP (tert-butyl hydroperoxide). The results showed that pretreatment with amifostine significantly attenuated cell apoptosis and death, accompanied by decreased reactive oxygen species (ROS) production and lower mitochondrial potential (ΔΨm). In vivo, amifostine pretreatment alleviated I/R injury and decreased myocardial apoptosis and infarct area, which was paralleled by increased superoxide dismutase (SOD) and reduced malondialdehyde (MDA) in myocardial tissues, increased Bcl2 expression, decreased Bax expression, lower cleaved caspase-3 level, fewer TUNEL positive cells, and fewer DHE-positive cells in heart. Our results indicate that amifostine pretreatment has a protective effect against myocardial I/R injury via scavenging ROS.

Radioprotection in mice following oral administration of WR-1065/PLGA nanoparticles

PURPOSE

N-(2-mercaptoethyl)1,3-diaminopropane (WR-1065), is the active metabolite of amifostine, a broad spectrum cytoprotective agent used in conjunction with both chemo- and radiotherapy of certain cancers. This report describes for the first time an oral formulation of WR-1065 and follows on from our earlier report of a similar oral formulation of amifostine.

MATERIALS AND METHODS

The nanoparticles of WR-1065 were prepared by spray drying technique using poly lactide-co-glycolide (PLGA) as the polymer matrix. Radioprotection was determined by measuring reductions in radiation-induced: (i) 30-day survival; (ii) bone marrow suppression; and (iii) intestinal injury following 9 Gray (Gy) whole body gamma irradiation in mice. All treatments were given 1 hour pre-irradiation and WR-1065 was tested at the dose of 500 mg/kg.

RESULTS

The WR-1065/PLGA nanoparticles were smooth and spherical with the average diameter of 206 nm and contained 21.7% (w/w) WR-1065. While irradiation markedly reduced 30-day survival in non-treated control mice, and caused significant bone marrow suppression and intestinal injury in surviving mice, oral administration of WR-1065/PLGA nanoparticles resulted in significant radioprotection as evidenced by a marked reduction in all three of the above mentioned parameters of radiation injury.

CONCLUSIONS

These findings clearly demonstrate the feasibility of developing an effective oral formulation of WR-1065 as a radioprotective agent.

Metabolomics using 1H-NMR of apoptosis and Necrosis in HL60 leukemia cells: differences between the two types of cell death and independence from the stimulus of apoptosis used

High-resolution proton nuclear magnetic resonance ((1)H-NMR) spectroscopy was used to examine and compare the metabolic variations that occur in cells of the HL60 promyelocytic leukemia cell line after induction of apoptosis by ionizing radiation and the antineoplastic drug doxorubicin as well as after induction of necrosis by heating. Apoptosis and necrosis were confirmed by fluorescence microscopy using the chromatin stain Hoechst 33258, agarose gel electrophoresis of DNA, and determination of caspase 3 enzymatic activity. The 1H-NMR experiments revealed that the spectra of both samples containing apoptotic cells were characterized by the same trend of several important metabolites. Specifically, an increase in CH2 and CH3 mobile lipids, principally of CH2, decreases in glutamine and glutamate, choline-containing metabolites, taurine and reduced glutathione were observed. By contrast, the sample containing necrotic cells presented a completely different profile of 1H-NMR metabolites since it was characterized by a significant increase in all the metabolites examined, with the exception of CH2 mobile lipids, which remain unchanged, and reduced glutathione, which decreased. The results suggest that variations in 1H-NMR metabolites are specific to apoptosis independent of the physical or chemical nature of the stimulus used to induce this mode of cell death, while cells dying from necrosis are characterized by a completely different behavior of the same metabolites.