The Role of Phospholipids in Mitochondrial Dynamics and Associated Diseases.

Abstract

The bioenergetic machinery of the cell is protected and structured within two layers of mitochondrial membranes. The mitochondrial inner membrane is extremely rich in proteins, including respiratory chain complexes, substrate transport proteins, ion exchangers, and structural fusion proteins. These proteins participate directly or indirectly in shaping the membrane's curvature and facilitating its folding, as well as promoting the formation of nanotubes, and proton-rich pockets known as cristae. Recent fluorescent super-resolution images have demonstrated the strong dynamics of these events, with constant remodeling processes. The mitochondrial outer membrane itself is also highly dynamic, interacting with the endoplasmic reticulum and its environment to ensure a rapid diffusion of surface components throughout the mitochondrial networks. All these movements occur besides migration, fusion, and fission of the mitochondria themselves. These dynamic events at the level of mitochondrial membranes are primarily dependent on their unique lipid composition. In this review, we discuss the latest advances in phospholipid research, focusing on their metabolism and role in mitochondrial dynamics. This process emphasizes the importance of interactions with the endoplasmic reticulum and mitochondrial matrix enzymes, extending its relevance to lipid sources, in particular, cardiolipins and phosphatidylethanolamines at the cellular, tissue and even whole-organism level. Given the expanding array of characterized mitochondrial functions, ranging from calcium homeostasis to inflammation and cellular senescence, research in the field of mitochondrial lipids is particularly significant. As mitochondria play a central role in various pathological processes, including cancer and neurodegenerative disorders, lipid metabolism may offer promising therapeutic approaches.