Mitochondria are membrane bound organelles that are found ubiquitously in eukaryotic cells. The role of mitochondria is thought to be predominantly for ATP generation, providing energy for the cells. However current research has suggested that they may also act as signalling organelles that control cytosolic Ca2+ signalling or even modify reactive oxygen species.
The number and function can vary wildly between organism, tissue and cell type; we are interested in the role these mitochondria play in endothelial and vascular smooth muscle cell signalling.
It is often reported that endothelial cells are highly glycolytic and do not rely on mitochondria for ATP production, but the majority of studies suggesting this were performed in cell culture systems where ATP production may be significantly altered from the native cell type.
By using TMRE dye to fluorescently label mitochondria (image on the left) and Cal-520 to label free cytosolic Ca2+ in live, en face tissue mesenteric artery preparations, we are studying this important relationship in more detail.
Work performed in the lab has also indicated that mitochondrial membrane potential is important for cytosolic Ca2+ signalling, leading to down stream vaso-contraction and -dilation. Data suggests that this is modulated by the reactive oxygen species, hydrogen peroxide, which is generated as a product of respiration within mitochondria.
Video 1: TIRF Depolarization
Lab members working on mitochondria: