Prefrontal Cortex Transcriptomic Deconvolution Implicates Monocyte Infiltration in Parkinson’s Disease

Abstract

<b><i>Introduction:</i></b> Although not considered a primary cause, neuroinflammation is associated with many neurodegenerative disorders, including Parkinson’s disease (PD). <b><i>Methods:</i></b> To elucidate potential immune involvement in PD, the present study imputed immune cell abundances from bulk RNA-sequencing transcriptomic data of PD postmortem prefrontal cortices. CIBERSORTx, an RNA deconvolution algorithm that implements support vector regression, was used to measure the relative abundances of immune cells from a previously published gene expression dataset. Through this machine-learning approach, relative proportions of 22 immune cell subtypes present in the original brain tissue were estimated. <b><i>Results:</i></b> Prefrontal cortices from PD patients exhibited significantly higher relative abundances of monocytes compared to neuropathologically normal controls (<i>p</i> value = 0.0005). The relative proportions of the other 21 immune subtypes showed no significant differences between control and PD samples. <b><i>Conclusion and Discussion:</i></b> The findings corroborate previous reports and suggest monocytes may be involved in PD pathogenesis.