# Imaging spatial transcriptomics reveals molecular patterns underlying accumulation of p-Ser129 α-synuclein in a transgenic mouse model

## TL;DR

This study uses imaging spatial transcriptomics to identify vulnerable neurons and molecular patterns linked to phosphorylated α-synuclein accumulation in a mouse model of Parkinson's disease.

## Contribution

The study reveals specific neuronal subtypes and genes, including Plk2 and hSNCA, associated with p-Ser129 α-synuclein accumulation in transgenic mice.

## Key findings

- Neuronal subtypes in the cortex and hippocampus preferentially develop p-Ser129 α-synuclein accumulation.
- Plk2 and hSNCA are key to p-Ser129 α-synuclein development in vulnerable neurons.
- p-Ser129 α-synuclein alters mitochondrial and endolysosomal gene expression.

## Abstract

In Parkinson’s disease and dementia with Lewy bodies, aggregated and phosphorylated α-synuclein appears in select neurons throughout cortical and subcortical regions, but little is currently known about why certain populations are selectively vulnerable. Here, using imaging spatial transcriptomics (IST) coupled with downstream immunofluorescence for α-synuclein phosphorylated at Ser129 (pSyn) in the same tissue sections, we identified neuronal subtypes in the cortex and hippocampus of transgenic human α-synuclein-overexpressing mice that preferentially developed pSyn accumulation. Additionally, we investigated the transcriptional underpinnings of this vulnerability, pointing to expression of Plk2, which phosphorylates α-synuclein at Ser129, and human SNCA (hSNCA), as key to pSyn development. Finally, we performed differential expression analysis, revealing gene expression changes broadly downstream of hSNCA overexpression, as well as pSyn-dependent alterations in mitochondrial and endolysosomal genes. Overall, this study yields new insights into the formation of phospho-α-synuclein and its downstream effects in a synucleinopathy mouse model.