A neuroglobin-based high-affinity ligand trap reverses carbon monoxide–induced mitochondrial poisoning
Jason J. Rose, Kaitlin Bocian, Qinzi Xu, Ling Wang, Anthony W. DeMartino, Xiukai Chen, Catherine Corey, Danielle A. Guimarães, Ivan Azarov, Xueyin N. Huang, Qin Tong, Lanping Guo, Mehdi Nouraie, Charles F. McTiernan, Christopher P. O’Donnell, Jesús Tejero, Sruti Shiva, Mark T. Gladwin
Abstract
Herein, we tested whether Ngb-H64Q-CCC can also scavenge CO from CcO and attenuate CO-induced inhibition of mitochondrial respiration. Heart tissue from mice exposed to 3% CO exhibited a 42 ± 19% reduction in tissue respiration rate and a 33 ± 38% reduction in CcO activity compared with unexposed mice. Intravenous infusion of Ngb-H64Q-CCC restored respiration rates to that of control mice correlating with higher electron transport chain CcO activity in Ngb-H64Q-CCC-treated compared with PBS-treated, CO-poisoned mice. Further, using a Clark-type oxygen electrode, we measured isolated rat liver mitochondrial respiration in the presence and absence of saturating solutions of CO (160 μm) and nitric oxide (100 μm). Both CO and NO inhibited respiration, and treatment with Ngb-H64Q-CCC (100 and 50 μm, respectively) significantly reversed this inhibition. These results suggest that Ngb-H64Q-CCC mitigates CO toxicity by scavenging CO from carboxyhemoglobin, improving systemic oxygen delivery and reversing the inhibitory effects of CO on mitochondria. We conclude that Ngb-H64Q-CCC or other CO scavengers demonstrate potential as antidotes that reverse the clinical and molecular effects of CO poisoning.