Tsalenchuk, M. | bioRxiv Science

bioRxiv2025

17q21.31 locus regulates Parkinson's disease relevant pathways through KANSL1 activity

An inversion polymorphism at the 17q21.31 locus defines the H1 and H2 haplotypes, with the former linked to multiple neurodegenerative disorders, including an increased risk of Parkinsons disease (PD). Although the high linkage disequilibrium at this locus has made it difficult to decipher which gene(s) drive the PD association, there is increasing evidence to support the role of KANSL1 as a risk gene. KANSL1 has been shown to regulate the expression of some PD-associated genes and pathways, likely as part of the histone acetylating non-specific lethal (NSL) complex. Here for the first time, we studied the global effects of 17q21.31 haplotype variation using bulk and single-nuclear RNA-sequencing data from control and PD patient brain. We first analysed differential gene expression across haplotype groups, and then assessed the contribution of KANSL1 by comparing with the results of an siRNA knockdown in neuronal and glial human cell lines. We demonstrated that the PD risk-associated H1 haplotype downregulates autophagy, lysosomal and mitochondrial processes, all of which have already been implicated in PD aetiology. Furthermore, these effects were apparent in both neuronal and glial cell types, and in the case of the latter, appear to be associated with the modulation of innate and adaptive immune responses. Thus, we identify important links between NSL complex activity and PD pathophysiology that can be leveraged for novel therapeutic interventions.

neuroscience↗

bioRxiv2024

Unique nigral and cortical pathways implicated by epigenomic and transcriptional analyses in a rotenone rat model of Parkinson's disease

Pesticide exposure is increasingly recognised as a potential environmental factor contributing to the onset of idiopathic Parkinsons disease, yet the molecular mechanisms underlying this connection remain unclear. This study aims to explore how pesticide exposure disrupts key brain regions involved in Parkinsons disease pathology by reshaping gene regulatory landscapes. Using the well-established rotenone rat model of the disease, we performed H3K27ac ChIP-sequencing to profile active regulatory elements in the substantia nigra and cortex. In this model, rotenone distributes uniformly throughout the brain, and the degree of complex I inhibition is equivalent in cortical and substantia nigra neurons. Despite the uniformity of complex I inhibition, we identified widespread epigenomic differences, with brain region specific acetylation patterns associated with rotenone exposure. We showed consistent changes in transcriptomic activity by RNA-sequencing. Our results indicate there is a strong immune response to rotenone localised to the substantia nigra and highlight an enrichment of immune-related motifs in this brain region, suggesting that the immune response is at least partially driven by gene regulatory mechanisms. We also noted an increase in C1q complement pathway activity in the substantia nigra. In contrast, we identified widespread dysregulation of synaptic function at the gene regulatory level in the cortex of these same rats. Our results highlight a role for gene regulatory mechanisms potentially mediating the effects of pesticide exposure, driving region-specific functional responses in the brain that may contribute to the pathology and selective vulnerability that characterise Parkinsons disease.

genomics↗