Mitochondria and calcium in health and disease

Abstract

Over recent years, we have witnessed a huge shift in understanding of the roles of mitochondria both in the regulation of normal cell physiology and also in dictating the progression of disease. This introductory essay gives a broad overview of the reviews included within the special issue and attempts to place them together in the broad context of our understanding of the roles of mitochondria in cell signalling and in pathophysiology of a range of major diseases. We, as the editors, hope that this special issue will provide a valuable contribution to the literature in this exciting and fast developing field. Look up ‘mitochondria’ in a cell biology or biochemistry text book and you will be presented with maps of biochemical pathways and details of a double membrane structure with a hugely folded inner membrane forming ‘cristae’. You will find detailed descriptions of the TCA cycle and schemes that explain the bioenergetic principles that govern the generation of ATP, and you will no doubt find descriptions of the pathways that govern cell death. The word ‘calcium’ may not be mentioned at all. However, it has been well established for very many years that mitochondria have a huge capacity to accumulate calcium. While the physiological significance of this pathway was hotly debated until relatively recently, it is now clear that mitochondrial roles in calcium handling are ubiquitous and have been described in every cell system in which the issue has been addressed. Further-