Giorgia Mellia,
,
, Michela Taianaa, Francesca Camozzia, Daniela Trioloc, Paola Podinic, Angelo Quattrinic, Franco Taronib and Giuseppe Lauriaa
Abstract
The study investigates if alpha-lipoic acid is neuroprotective against chemotherapy induced neurotoxicity, if mitochondrial damage plays a critical role in toxic neurodegenerative cascade, and if neuroprotective effects of alpha-lipoic acid depend on mitochondria protection.
We used an in vitro model of chemotherapy induced peripheral neuropathy that closely mimic the in vivo condition by exposing primary cultures of dorsal root ganglion (DRG) sensory neurons to paclitaxel and cisplatin, two widely used and highly effective chemotherapeutic drugs. This approach allowed investigating the efficacy of alpha-lipoic acid in preventing axonal damage and apoptosis and the function and ultrastructural morphology of mitochondria after exposure to toxic agents and alpha-lipoic acid. Our results demonstrate that both cisplatin and paclitaxel cause early mitochondrial impairment with loss of membrane potential and induction of autophagic vacuoles in neurons. Alpha-lipoic acid exerts neuroprotective effects against chemotherapy induced neurotoxicity in sensory neurons: it rescues the mitochondrial toxicity and induces the expression of frataxin, an essential mitochondrial protein with anti-oxidant and chaperone properties. In conclusion mitochondrial toxicity is an early common event both in paclitaxel and cisplatin induced neurotoxicity. Alpha-lipoic acid protects sensory neurons through its anti-oxidant and mitochondrial regulatory functions, possibly inducing the expression of frataxin. These findings suggest that alpha-lipoic acid might reduce the risk of developing peripheral nerve toxicity in patients undergoing chemotherapy and encourage further confirmatory clinical trials.
Keywords: Neurotoxicity; Mitochondria; Chemotherapy; Alpha-lipoic acid; Frataxin
Article Outline
- Materials and methods
- Neuronal cells and Schwann cells cultures
- Neuroprotection assay: axonal outgrowth measurement
- Neuroprotection assay: neuronal apoptosis
- Mitochondrial function assay
- Mitochondrial membrane potential changes assay
- Electron microscope analysis
- Real-time PCR assay
- Small interfering RNA experiments
- Results
- Alpha-lipoic acid protect sensory neurons against paclitaxel and cisplatin induced axonal damage and apoptosis
- Paclitaxel and cisplatin neurotoxicity is associated with a reduction of functioning mitochondria in DRG cultures
- Alpha-lipoic acid prevents the early loss of membrane potential differential in mitochondria exposed to paclitaxel and cisplatin
- Alpha-lipoic acid rescues mitochondrial morphological abnormalities induced by paclitaxel and cisplatin
- Alpha-lipoic acid induces frataxin expression in sensory neurons