FIGURE 1.

Mitochondrial functions. Left panel: under physiological conditions, mitochondria functions are the core of bioenergetics activities, providing ATP throughout the OXPHOS, which is also an important source of ROS. Basal ROS levels are maintained by the radical scavenging network. Additionally, mitochondria are calcium-buffering organelles. Ca²⁺ homeostasis is finely controlled by its uptake through voltage-dependent anion-selective channel proteins (VDACs) and the mitochondrial Ca²⁺ uniporter (MCU) complex, Ca²⁺ efflux is controlled by NCLX. Right top panel: pathological conditions, ROS burst and mitochondrial Ca²⁺ overload activate regulated cell death (RCD) inducing either apoptosis or necrosis pathway through the PTPC opening. Right-bottom panel: Ca²⁺ uptake activates mitochondrial metabolism. Fatty acids are metabolized via FAO toward the TCA cycle providing energy as FADH₂ and NADPH are building blocks for biosynthesis. Voltage-dependent anion-selective channel proteins (VDAC), Mitochondrial Calcium Uniporter Complex (MCUC), Mitochondrial Na⁺/Ca²⁺ exchanger (NCLX), oxidative phosphorylation (OXPHOS), Permeability transition pore complex (PTPC), ADP/ATP translocase (ANT) and peptidyl-prolyl cis-trans isomerase Cyclophilin D (CypD), cytochrome C (cyt C), adenosine triphosphate (ATP), reactive oxygen species (ROS), tricarboxylic acid cycle (TCA), fatty acid oxidation (FAO), α -ketoglutarate dehydrogenase (α-KG), oxaloacetate (OAA), Acetyl coenzyme A (Acetyl CoA) mitochondrial membrane potential (Δψ_m) (Created with BioRender.com).