Scientific Publications by FDA Staff
Toxicology 2013 Feb 8;304:109-19
6-OHDA-induced apoptosis and mitochondrial dysfunction are mediated by early modulation of intracellular signals and interaction of Nrf2 and NF-kappaB factors.
Tobon-Velasco JC, Limon-Pacheco JH, Orozco-Ibarra M, Macias-Silva M, Vazquez-Victorio G, Cuevas E, Ali SF, Cuadrado A, Pedraza-Chaverri J, Santamaria A
6-Hydroxydopamine (6-OHDA) is a neurotoxin that generates an experimental model of Parkinson's disease in rodents and is commonly employed to induce a lesion in dopaminergic pathways. The characterization of those molecular mechanisms linked to 6-OHDA-induced early toxicity is needed to better understand the cellular events further leading to neurodegeneration. The present work explored how 6-OHDA triggers early downstream signaling pathways that activate neurotoxicity in the rat striatum. Mitochondrial function, caspases-dependent apoptosis, kinases signaling (Akt, ERK 1/2, SAP/JNK and p38) and crosstalk between nuclear factor kappa B (NF-kappaB) and nuclear factor-erythroid-2-related factor 2 (Nrf2) were evaluated at early times post-lesion. We found that 6-OHDA initiates cell damage via mitochondrial complex I inhibition, cytochrome c and apoptosis-inducing factor (AIF) release, as well as activation of caspases 9 and 3 to induce apoptosis, kinase signaling modulation and NF-kappaB-mediated inflammatory responses, accompanied by inhibition of antioxidant systems regulated by the Nrf2 pathway. Our results suggest that kinases SAP/JNK and p38 up-regulation may play a role in the early stages of 6-OHDA toxicity to trigger intrinsic pathways for apoptosis and enhanced NF-kappaB activation. In turn, these cellular events inhibit the activation of cytoprotective mechanisms, thereby leading to a condition of general damage.
|Category: Journal Article|
|PubMed ID: #23274087||DOI: 10.1016/j.tox.2012.12.011|
|Includes FDA Authors from Scientific Area(s): Toxicological Research|
|Entry Created: 2013-04-28|