Mitochondria Have Made a Long Evolutionary Path from Ancient Bacteria Immigrants within Eukaryotic Cells to Essential Cellular Hosts and Key Players in Human Health and Disease

Abstract

Mitochondria have made a long evolutionary path from ancient bacteria immigrants within the eukaryotic cell to become key players for the cell, assuming crucial multitasking skills critical for human health and disease. Traditionally identified as the powerhouses of eukaryotic cells due to their central role in energy metabolism, these chemiosmotic machines that synthesize ATP are known as the only maternally inherited organelles with their own genome, where mutations can cause diseases, opening up the field of mitochondrial medicine. More recently, the omics era has highlighted mitochondria as biosynthetic and signaling organelles influencing the behaviors of cells and organisms, making mitochondria the most studied organelles in the biomedical sciences. In this review, we will especially focus on certain ‘novelties’ in mitochondrial biology “left in the shadows” because, although they have been discovered for some time, they are still not taken with due consideration. We will focus on certain particularities of these organelles, for example, those relating to their metabolism and energy efficiency. In particular, some of their functions that reflect the type of cell in which they reside will be critically discussed, for example, the role of some carriers that are strictly functional to the typical metabolism of the cell or to the tissue specialization. Furthermore, some diseases in whose pathogenesis, surprisingly, mitochondria are involved will be mentioned.

Differentiating Compromised Mitochondria of Lung Cancer Cells from Mitochondria in Healthy Cells

“…In 1978, Mitchell received a Nobel Prize for his chemiosmotic theory about the anisotropic arrangement of components which play a role in ATP synthesis within the proton's impermeable inner mitochondrial membrane so electrons transferring and protons expelling across the membrane can be done by complexes. It helped set a base for a meticulous understanding of the processes of OXPHOS [3]. In 1981, the MRC Laboratory of Molecular Biology in Cambridge found the sequence of the human mitochondrial genome [32].…”

“…As per Nick Lane, an English biochemist and writer, "Gram per gram, even when sitting comfortably, you are converting 10,000 times more energy than the sun every second" [2]. Specialty and uniqueness lie in the fact that mitochondria contain their DNA, which is very similar to bacterial DNA [3]. This makes them entirely diff erent from other cellular organelles [3].…”

“…Specialty and uniqueness lie in the fact that mitochondria contain their DNA, which is very similar to bacterial DNA [3]. This makes them entirely diff erent from other cellular organelles [3]. These organelles are responsible for a remarkable set of cellular functions, for example; generating ATP via oxidative phosphorylation, maintaining cellular redox homeostasis, regulating apoptosis, and intracellular calcium signaling [4][5][6].…”

Mitochondria in Alzheimer’s Disease Pathogenesis

“…They are involved in cellular bioenergetic and signaling pathways and metabolic adaptations to keep the cell and organism alive [13]. They are vital for ATP production through oxidative phosphorylation and for maintaining calcium homeostasis [14,15]. Mitochondria are rod-shaped double-membrane structures ranging in length from 0.5 µm to 1 µm [16].…”