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ROFA INCREASES CASPASE-3 ACTIVITY IN HUMAN ALVEOLAR MACRAPHAGE
Citation:
Soukup, J M., S. Becker, AND Huang, YuhChin T. ROFA INCREASES CASPASE-3 ACTIVITY IN HUMAN ALVEOLAR MACRAPHAGE. Presented at American Thoracic Society Annual Meeting, San Francisco, CA, May 18-23, 2001.
Description:
Exposure to air pollution particles produces pulmonary inflammation and injury, but the mechanisms of this injury are unclear. Apoptosis, involving activation of caspases, may be one potential mechanism. In this study, we hypothesized that ROFA, a constituent of air pollution particles, may increase caspase-3 activity in human alveolar macrophage (AM) by an NO-dependent mechanism. AM (106 cells) were incubated 4 hr with anti-Fas antibody (5 mg), ROFA (100 mg) and vanadyl sulfate (VOSO4, 50 mM) with or without L-NAME, (a nitric oxide synthase inhibitor, 100 mM). Additional AM were incubated with DetaNONOate (an NO donor, 1 mM), L-arginine (3 mM) and L-ornithine (3 mM) to determine the effects of NO and arginase activation on caspase-3 activation. Caspase-3 activity was measured using a fluorescent substrate assay. The control AM had caspase-3 activity of 41? 4 mM/mg protein. Anti-Fas, ROFA and VOSO4 increased caspase-3 activity, while addition of Z-DEVD-FMK inhibited it. The caspase-3 activity with different interventions expressed as % control are shown below.
Untreated L-NAME L-Ornithine
Control 100 ? 0 79 ? 12 94 ? 8
Anti-Fas 264 ? 37* 186 ? 31 381 ? 15**
ROFA 211 ? 38* 125 ? 21# 268 ? 35
VOSO4 154 ? 18* 88 ? 3# 149 ? 33
(*: p < 0.05 vs. control; # p < 0.05 vs. untreated; **: p < 0.05 vs. Anti-Fas)
Both DetaNONOate and L-arginine increased caspase-3 activity to 200% control. Taken together these results indicate that ROFA and VOSO4 increase caspase-3 activity in AM via mechanisms that differ from those of anti-Fas, and are NO-dependent.
This is a proposed presentation and does not necessarily reflect EPA policy.