A pathogenic mutation in the ALS/FTD gene VCP induces mitochondrial hypermetabolism by modulating the permeability transition pore.

Abstract

Valosin-containing protein (VCP) is a ubiquitously expressed type II AAA⁺ ATPase protein, implicated in both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). This study aimed to explore the impact of the disease-causing VCP^R191Q/wt mutation on mitochondrial function using a CRISPR/Cas9-engineered neuroblastoma cell line. Mitochondria in these cells are enlarged, with a depolarized mitochondrial membrane potential associated with increased respiration and electron transport chain activity. Our results indicate that mitochondrial hypermetabolism could be caused, at least partially, by increased calcium-induced opening of the permeability transition pore (mPTP), leading to mild mitochondrial uncoupling. In conclusion, our findings reveal a central role of the ALS/FTD gene VCP in maintaining mitochondrial homeostasis and suggest a model of pathogenesis based on progressive alterations in mPTP physiology and mitochondrial energetics.