Whole mitochondrial sequencing in patients with Parkinson's disease from Brazilian Amazon

Parkinson's disease (PD) is the most prevalent neurodegenerative movement disorder, characterized by the progressive death of dopaminergic neurons and depletion of dopamine in the striatum. This is responsible for the motor symptoms, such as bradykinesia, rigidity, postural instability and rest tremor. Although the biological features underlying the degeneration of dopaminergic neurons have not yet been fully described, in recent decades the scientific community became aware of mitochondrial dysfunction as key aspects of PD pathogenesis. Mitochondria are organelle widely known for their physiological role in producing ATP as an energy source and regulating cell death. Moreover, they markedly differentiate from other organelles for having their own genome (mtDNA), which encodes 13 proteins for oxidative phosphorylation (OXPHOS) complexes, 22 tRNAs and two encodes for rRNAs. The mtDNA also contains non-coding regions, such as the displacement loop (D-loop), where are located the sequences for the initiation of replication and transcription. Hence, mtDNA variants can trigger mitochondrial dysfunction, which adversely affects the bioenergetic functions of cells, being even able to lead to neuronal death. In this context, the present project aims sequence the whole mitochondrial genome of PD patients and age-matched healthy individuals from the Brazilian Amazon and analyze the effect of mtDNA variants in the susceptibility to PD. To do so, were collected the total blood of 45 patients with PD and 42 individuals for the control group. The extraction of the total DNA was performed using theMagMAX™ DNA Multi-Sample Kit, and the mtDNA was amplified byPCRwith 33 specific pairs of primers, for subsequent sequencing in the MiSeq system. After sequencing, we performed the analysis of variants and levels of heteroplasmy in order to compare the case and control groups and investigate the influence of mitochondrial genetics on the development of PD