OPA1 and amyotrophic lateral sclerosis: The accumulation of the ALS-related SOD1G93A mutant protein in mitochondria will cause the downregulation of OPA1, resulting in multiple mitochondrial defects, including ultrastructural disorder, fusion inhibition, maturation obstruction, and cristae swelling, ultimately leading to the loss of mitochondrial membrane potential, reduced respiratory capacity, and increased production of ROS [52].