The effects of morphine on Parkinson’s-related genes PINK1 and PARK2

BACKGROUND Parkinson's disease (PD) continues to be an important neurological disorder. It is caused by the loss of dopaminergic neurons in the substantia nigra. Dopamine, the neurotransmitter produced from dopaminergic neurons, is a major precursor of endogenous morphine. There are approximately 18 genes associated with PD; their roles have not yet been completely established. PARK2 is a gene that encodes for the protein parkin, and PINK1 is a gene that encodes for PTEN-induced putative kinase 1. MATERIAL AND METHODS Our objective was to determine if morphine treatment of HTB-11 cells affects the expression of PINK1 and PARK2. HTB-11 cells were treated with 10-7 M morphine for 2 h and a microarray analysis was conducted. To verify the microarray analysis, 3 Q-PCR trials were run using 10-6 M naloxone, morphine (10-7 M), or a naloxone/morphine mix. RESULTS In both the microarray analysis and the Q-PCR analysis, PARK2 was up-regulated and PINK1 was down-regulated. CONCLUSIONS Morphine can affect the expression of PD-associated genes.