Fig. 2: Distribution of PLIN2 in the spatial transcriptome and its regulation of M2 polarization in THP-1-derived macrophages.

A Spatial distribution of PLIN2 expression across the tissue section. Color intensity indicates the relative expression level of PLIN2. B Unsupervised clustering of spatial transcriptomic spots. Each color denotes a distinct cluster identified based on global gene expression patterns. C Bar plot showing the expression of PLIN2 across the identified transcriptomic clusters. The y-axis indicates the normalized expression level, and the x-axis lists each cluster. D UMAP projection illustrating PLIN2 expression at the single-cell level. E UMAP projection annotated by cell type inferred from canonical marker genes. F Bar plot depicting PLIN2 expression levels across the major annotated cell types. The y-axis indicates normalized expression, and the x-axis lists each cell type. G Schematic diagram of the experimental procedure for induction of macrophage polarisation from THP-1 cells. H–I qRT-PCR analysis revealed that PLIN2 overexpression significantly downregulated M1 macrophage markers while upregulating M2-associated genes in THP-1 cells. J–L PLIN2 promotes the transformation of THP-1-derived macrophages to the M2 subtype as detected by flow cytometry. Data are shown as mean ± SD. *p < 0.05, **p < 0.01, ***p < 0.001.