Mitochondrial Stress by Toxic Elements - An Overview

Abstract

Mitochondria (mT) are now considered as suitable targets of toxicity induced by various environmental xenobiotics. Mitochondrial dysfunction is the final outcome of their effects in cellular system. Human diseases viz. Alzheimer, parkinsonism, pancreatic β cell failure, insulin resistance and ageing have also been partially attributed to mitochondrial injury. Present review focuses mainly on mitochondrial stress induced by a few toxic elements i.e. cadmium, mercury, lead, copper, chromium, nickel and arsenic. General mechanisms that cause mT dysfunction including generation of reactive oxygen species, oxidative stress, apoptosis alterations in mT membrane permeability and energy disturbances have been discussed. Further, specific effects of toxic elements i.e. inhibition of ATPase, activation of caspases, enhanced release of cytochrome c and mT DNA damage have also been described. In few cases, cytokines were also involved in mT dysfunction. Their effects on mT biogenesis is also reported. Investigations on certain less understood paradigms viz. mitochondrial hormesis, mitophagy and mitokines are urgently needed.