N-acetylcysteine and vitamin E rescue animal longevity and cellular oxidative stress in pre-clinical models of mitochondrial complex I disease

Abstract

Oxidative stress is a known contributing factor in mitochondrial respiratory chain (RC) disease pathogenesis. Yet, no efficient means exists to objectively evaluate the comparative therapeutic efficacy or toxicity of different antioxidant compounds empirically used in human RC disease. We postulated that pre-clinical comparative analysis of diverse antioxidant drugs having suggested utility in primary RC disease using animal and cellular models of RC dysfunction may improve understanding of their integrated effects and physiologic mechanisms, and enable prioritization of lead antioxidant molecules to pursue in human clinical trials. Here, lifespan effects of N-acetylcysteine (NAC), vitamin E, vitamin C, coenzyme Q10 (CoQ10), mitochondrial-targeted CoQ10 (MS010), lipoate, and orotate were evaluated as the primary outcome in a well-established, short-lived C. elegans gas-1(fc21) animal model of RC complex I disease. Healthspan effects were interrogated to assess potential reversal of their globally disrupted in vivo mitochondrial physiology, transcriptome profiles, and intermediary metabolic flux. NAC or vitamin E fully rescued, and coenzyme Q, lipoic acid, orotic acid, and vitamin C partially rescued gas-1(fc21) lifespan toward that of wild-type N2 Bristol worms. MS010 and CoQ10 largely reversed biochemical pathway expression changes in gas-1(fc21) worms. While nearly all drugs normalized the upregulated expression of the "cellular antioxidant pathway", they failed to rescue the mutant worms' increased in vivo mitochondrial oxidant burden. NAC and vitamin E therapeutic efficacy were validated in human fibroblast and/or zebrafish complex I disease models. Remarkably, rotenone-induced zebrafish brain death was preventable partially with NAC and fully with vitamin E. Overall, these pre-clinical model animal data demonstrate that several classical antioxidant drugs do yield significant benefit on viability and survival in primary mitochondrial disease, where their major therapeutic benefit appears to result from targeting global cellular, rather than intramitochondria-specific, oxidative stress. Clinical trials are needed to evaluate whether the two antioxidants, NAC and vitamin E, that show greatest efficacy in translational model animals significantly improve the survival, function, and feeling of human subjects with primary mitochondrial RC disease.

Drug repurposing for mitochondrial diseases using a pharmacological model of complex I deficiency in the yeastYarrowia lipolytica

“…As has been done for another nuclear encoded assembly factor gene in Yarrowia lipolytica (Gerber et al, 2017), hypomorphic NDUFA8 missense mutants are being generated now in collaboration with a lab at Clemson University so that the piericidin A suppressors described herein will be tested for their ability to rescue the growth defects of this mutant. Once validated in yeast and patient derived cells (fibroblasts, followed by iPSCs), piericidin A suppressors can be further validated in complex I deficient worms (Polyak et al, 2018), flies (Cabirol-Pol et al, 2018) and zebrafish (Pinho et al, 2013). Cross-species validated piericidin A suppressors that are FDA approved drugs have a clear path to the clinic, starting in so called N-of-1 trials.…”

N-acetylcysteine prevents ketamine-induced adverse effects on development, heart rate and monoaminergic neurons in zebrafish

“…Our studies show that 1 mM NAC could effectively prevent ketamine-induced growth retardation and attenuated heart rate. NAC at 1 mM has been shown to partially prevent rotenone-induced cell death in the larval zebrafish brain [29]. …”

Strategies for fighting mitochondrial diseases

“…N‐acetyl cysteine (NAC) and vitamin E were able to rescue the phenotype of gas‐1(fc21) in mutant nematodes, carrying a mutation in the orthologue of complex I 49 KDa subunit (NDUFS2) [44]. CoQ, lipoate, orotate and vitamin C partially prolonged the lifespan of the same model [44]. These results were possibly due to a reduction of oxidative stress without correction of the underlying mitochondrial defect [44].…”

“…CoQ, lipoate, orotate and vitamin C partially prolonged the lifespan of the same model [44]. These results were possibly due to a reduction of oxidative stress without correction of the underlying mitochondrial defect [44]. In another series of experiment, probucol rescued zebrafish developmental delay induced by rotenone inhibition of complex I and oligomycin‐dependent complex V inhibition, but failed to rescue complex IV inhibition by azide [45].…”