DNAJB6 is expressed in neurons and oligodendrocytes of the human brain

DNAJB6 is a suppressor of α-synuclein aggregation in vivo and in vitro. DNAJB6 is strongly expressed in the brain, and its overall protein expression is altered in neurodegenerative conditions such as Parkinson's Disease (PD) and Multiple System Atrophy (MSA). These two diseases are characterized by accumulation of aggregated α-synuclein in neurons and oligodendrocytes, respectively. To further explore this, we employed post-mortem normal human brain material to investigate the regional and cell type specific protein expression of DNAJB6. We found that the DNAJB6 protein is ubiquitously expressed across various regions of the brain. Notably, we demonstrate for the first time that DNAJB6 is present in nearly half (41%–53%) of the oligodendrocyte population and in the majority (68%–80%) of neurons. However, DNAJB6 was only sparsely present in other cell types such as astrocytes and microglia. Given that α-synuclein aggregation in oligodendrocytes is a hallmark of MSA, we investigated DNAJB6 presence in MSA brains compared to control brains. We found no significant difference in the percentage of oligodendrocytes where DNAJB6 was present in MSA brains relative to control brains. In conclusion, our results reveal an expression of the DNAJB6 protein across various regions of the human brain, and that DNAJB6 is almost exclusively present in neurons and oligodendrocytes. Since prior studies have shown that PD and MSA brains have altered levels of DNAJB6 relative to control brains, DNAJB6 may be an interesting target for drug development.