Full length PGC-1α salvages the phenotype of a mouse model of human neuropathy through mitochondrial proliferation

Authors
K. Rona-Voros, J. Eschbach, A. Vernay, D. Wiesner, B. Schwalenstocker et al.

Lab
Faculté de Médecine, Strasbourg, France

Journal
Human Molecular Genetics

Abstract
Increased mitochondrial numbers, commonly termed mitochondrial proliferation, is frequently observed in many human diseases directly or indirectly involving mitochondrial dysfunction. Mitochondrial proliferation is thought to counterbalance a compromised energy metabolism, yet it might also be detrimental through alterations of mitochondrial regulatory functions such as apoptosis, calcium metabolism or oxidative stress. Here we show that prominent mitochondrial proliferation occurs in Cramping mice, a model of hereditary neuropathy caused by a mutation in the dynein heavy chain gene Dync1h1. The mitochondrial proliferation correlates with post-prandial induction of full length (FL) and N-terminal truncated (NT) isoforms of the transcriptional co-activator PGC-1α. The selective knock-out of FL-PGC-1α isoform, preserving expression and function of NT-PGC-1α, led to a complete reversal of mitochondrial proliferation. Moreover, FL-PGC-1α ablation potently exacerbated the mitochondrial dysfunction and led to severe weight loss. Last, FL-PGC-1α ablation triggered pronounced locomotor dysfunction, tremors and inability to rear in Cramping mice. In summary, endogenous FL-PGC-1α activates mitochondrial proliferation and salvages neurological and metabolic health upon disease. NT-PGC-1α cannot fulfill this protective action. Activation of this endogenous salvage pathway might thus be a valuable therapeutic target for diseases involving mitochondrial dysfunction.

BIOSEB Instruments Used:
Grip strength test (BIO-GS3)