Brain transcriptomic profiling in idiopathic and LRRK2-associated Parkinson's disease

LRRK2 mutations are the most common genetic cause of Parkinson’s disease (PD). We performed a whole-genome RNA profiling of locus coeruleus post-mortem tissue from idiopathic PD (IPD) and LRRK2-associated PD patients. The differentially expressed genes found in IPD and LRRK2-associated PD were involved in the gene ontology terms of synaptic transmission and neuron projection. In addition, in the IPD group we found associated genes belonging to the immune system. Pathway analysis of the differentially expressed genes in IPD was related with neuroactive-ligand receptor interaction and with immune system pathways. Specifically, the analysis highlighted differential expression of genes located in the chromosome 6p21.3 belonging to the class II HLA. Our findings support the hypothesis of a potential role of neuroinflammation and the involvement of the HLA genetic area in IPD pathogenesis. Future studies are necessary to shed light on the relation of immune system related pathways in the etiopathogenesis of PD. Number of samples analyzed: 10 brain tissue (locus coeruleus). Control (C) samples, no pathological changes: C1, C2, C4, C5. Samples from idiopathic Parkinson's disease (IPD) patients: IPD1, IPD3, IPD4, IPD5. Samples from Parkinson's disease patients who are carriers of the G2019S LRRK2 mutation (MPD): MPD1, MPD2. No replicates.