Mitochondria Na+-Ca2+ exchange in cardiomyocytes and lymphocytes

Abstract

Mitochondria Na+-Ca2+ exchange (NCXmit) was first discovered by Carafoli et al. in 1974. Thereafter, the mechanisms and roles of NCXmit have been extensively studied. We review NCX mit in cardiomyocytes and lymphocytes by presenting our recent studies on it. Studies of NCXmit in rat ventricular cells demonstrated that NCXmit is voltage dependent and electrogenic. A targeted knockdown and knockout of NCLX in HL-1 cardiomyocytes and B lymphocytes, respectively, significantly reduced the NCXmit activity, indicating that NCLX is a major component of NCXmit in these cells. The store-operated Ca2+ entry was greatly attenuated in NCLX knockout lymphocytes, suggesting that substantial amount of Ca2+ enters into mitochondria and is released to cytosol via NCXmit. NCXmit or NCLX has pivotal roles in Ca2+ handling in mitochondria and cytoplasm. © Springer Science+Business Media New York 2013.