Fig. 4: Multi-omics analysis identifies TCA cycle bottleneck in PD.

A UMAP plot showing the main seven identified cell types. B Bar plot showing the ratio of each cluster in each group. C UMAP plot showing the four major neuronal subtypes. D UMAP distribution characteristics of each neuronal subtype in the normal group (left) and PD group (right). GO (E) and KEGG (F) analysis of DEGs in DaN. G Venn plots showing the overlapping genes between DaN DEGs and candidate mitochondrial gene sets in transcriptome data. H Representative images (left) and expression level analysis (right) of MDH2, IDH3G, and OGDHL protein expression in PD cell models. Data are mean ± SEM; n = 4–7 biological replicates.