This process could be caspase-dependent

or- independent and is mediated by MOMP associated with the generalized and irreversible dissipation of the mitochondrial transmembrane potential, release of mitochondrial intermembrane space proteins into the cytosol (and their possible relocalization to other subcellular compartments), and the respiratory chain inhibition Inhibitors,research,lifescience,medical [38]. Apoptosis plays a fundamental role in development and for maintenance of tissue homeostasis in the adult organism. In addition, Survivin inhibitor mw impairment of apoptosis may contribute to tumour progression. Nanomaterials are described as triggers of extrinsic and intrinsic apoptotic pathways; however, the Inhibitors,research,lifescience,medical oxidative stress paradigm of nanomaterials-induced cell death linked

to intrinsic apoptotic network is by far the most accepted, in fact many in vitro studies have identified increased ROS generation as an initiating factor of toxicity in nanomaterials exposed cells [3, 6, 7, 10, 39]. Although it is well established that the mode of cell death depends Inhibitors,research,lifescience,medical on the severity of the cellular insult (which may, in turn, be linked to mitochondrial function and intracellular energy), it has been difficult to set up a comprehensive mechanism of nanomaterials cell death based on conflicting observations present in the literature. Furthermore, in most of the studies, the molecular mechanisms underlying cell death are not investigated. Finally, another problem is the nonhomogeneity of the studies, in terms of materials and experimental methods used, which makes it difficult to compare. Sarkar and colleagues showed Inhibitors,research,lifescience,medical that the nano-copper induces intrinsic apoptotic cell death in mice kidney tissue (via the increase of ROS and reactive nitrogen species production, regulation of Bcl-2 family protein expression, release of cytochrome c from mitochondria to cytosol, and activation of caspase-3), Inhibitors,research,lifescience,medical but, in addition, they observed the activation of FAS, caspase-8, and tBID, suggesting also the involvement of extrinsic pathways

[40]. The exposure to nano-copper dose-dependently caused oxidative stress and led to hepatic dysfunction in vivo. Nano-copper caused the reciprocal regulation of Bcl-2 family proteins, disruption of mitochondrial membrane potential, release of cytochrome c, formation of apoptosome, and activation of caspase-3. These the results indicate that nano-copper induces hepatic dysfunction and cell death via the oxidative stress-dependent signalling cascades and mitochondrial event [41]. Metallic nickel nanoparticles induced apoptotic cell death through an FAS/caspase-8/BID mediated, cytochrome c-independent pathway in mouse epidermal cells [42]. Nickel oxide nanoparticles excited in dose-dependent manner the increase of ROS production, lipid peroxidation, and caspase-3 activation in human airway epithelial and breast cancer cells [43].