Expression of PINK1 mRNA in human and rodent brain and in Parkinson's disease

Mutations in PINK1 (PTEN-induced putative kinase 1) are causal for early onset recessive parkinsonism in humans, characterized by damage to the nigrostriatal system. In situ hybridization studies in rodent brains have suggested a predominantly neuronal expression of PINK1 mRNA but immunocytochemistry of human brain tissue has shown PINK1-like immunoreactivity in both neurons and glia. In this study, we assessed the comparative distribution of PINK1 mRNA in human, rat and mouse brain. We observe that in humans PINK1 message is expressed in neurons with very little to no signal in glia and confirms similar findings in rodent tissue. Highest levels of expression were observed in hippocampus, substantia nigra and cerebellar Purkinje cells. We also show that PINK1 mRNA expression is similar in nigral neurons from neurologically normal controls and sporadic Parkinson's disease cases.