Therapeutic effects of neuronal PTEN-knockout reveal a critical role of mitochondrial dysfunction in sustaining locomotor deficits chronically after spinal cord injury

ABSTRACT: Neuron-specific PTEN-knockout has demonstrated an ability to induce axon regeneration after spinal cord injury (SCI) as well as restore motor functions through regeneration-independent mechanisms. To better understand the biological effects of neuron-specific PTEN-KO, PTENflox mice (Male/Female mix) were treated with spinal cord injections of a retrogradely transported adeno-associated virus (AAVrg) to deliver Cre-recombinase under a Synapsin1 (Syn1) promoter. Naïve, SCI-eGFP, and SCI-Cre-eGFP groups were compared for analyses. AAVrg’s were delivered immediately after SCI and spinal cords were harvested 6 weeks post 100 kDyn contusion. Protein homogenates obtained from whole-spinal cord samples above, and including, the lesion were assessed for total- and phospho-proteomics. Amongst the largest observations from total proteomics, we observed a major injury-induced decrease in mitochondrial proteins, with a notable loss of Complex I subunits, chronically after SCI. In contrast, amongst the largest treatment mediated effects in total proteomics was a PTEN-KO induce increase in mitochondrial peptides, also notably reversing the loss of Complex I mediated subunits. Next, we replicated our experimental model and isolated mitochondria from whole spinal-cord extracts and evaluated for respiratory functions through the electron transport chain which revealed a global decrease in mitochondrial respiration chronically after SCI. PTEN-KO reversed mitochondrial dysfunctions observed chronically after injury. Notably, the largest treatment effect was observed in Complex I mediated respiration, validating the predictions made from total proteomics. To determine the extent that specifically targeting mitochondrial functions can mediate improvements chronically after SCI, we injured mice using a 90 kDyn contusion and injected an AAVrg to overexpress PGC1α as a master regulator of mitochondria and metabolism.

INSTRUMENT(S):

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Spinal Cord

DISEASE(S): Spinal Cord,Wounds And Injuries

SUBMITTER: Carlos Gartner  

LAB HEAD: Calvin Vary

PROVIDER: PXD067597 | Pride | 2026-06-10

REPOSITORIES: pride