Is cholesterol bad for mitochondria?


by Sayuri Miyamoto

Cholesterol is an important component of cell membranes and plays essential structural and signaling roles. It is synthesized in the endoplasmic reticulum and distributed to other cell membranes/compartments through a tightly regulated trafficking system involving vesicular and non-vesicular processes [1]. Cholesterol distribution among intra-cellular membranes is not homogeneous. Mitochondria are cholesterol-poor organelles (less than 5 %). However, mitochondrial cholesterol is increased in cancer cell lines and treatment of these cells with statins (cholesterol lowering drugs) increases their susceptibility to chemotherapy [2].

How mitochondrial cholesterol could influence


The new roles of cardiolipin in ROS-mediated signalling

Cytochrome c

by Alberto Lévano-Martinez

Cardiolipin, the signature phospholipid of mitochondria, has been extensively studied as this organelle’s main structural and regulatory lipid. It exerts influential roles in the catalytic activity of key components of the oxidative phosphorylation under physiological conditions. However, recents advances in mitochondrial physiology have uncovered roles of this phospholipid in pathophysiological situations such as apoptosis, or in Barth syndrome. Cardiolipin anchors cytochrome c to the outer face of the inner mitochondrial membrane, which favors the electron transfer to the terminal component of the respiratory chain (Complex IV). However, during oxidative