FIGURE 1.

Identification of cell clusters and cell types in TG. (A) UMAP projection of cell clusters and cell types. Unsupervised cell clustering and cell type annotation identify 17 distinct cell clusters (C1–C17) and 5 cell types, including neurons, glial cells, immune cells, fibroblasts and endothelial cells. Each dot represents one cell; Each color represents one cluster or one cell type. (B) Bar plot showing proportions of each cell type in each TG sample. (C) Stacked violin plot showing the distribution of known marker genes (e.g., neuronal marker genes: Tubb3 and Rbfox3) in each cluster. The width of the violin plots represents density distributions, the height represents gene expression levels [normalized (counts)], and each color represents one cluster. C1–C6 were identified as neurons by high expression of Tubb3 and Rbfox3, C7–C11 were identified as glial cells by Plp1, C12-C15 were identified as immune cells by Ptprc, C16 was identified as fibroblasts by Dcn and Col1a1, C17 was identified as endothelial cells by Flt1 and Pecam1. (D) Schematic illustration of purinergic signaling in TG. Extracellular ATP is released from TG cells via vesicular exocytosis and Cxs/Panx channels; ATP-activated P2XRs mediate non-selective cation influx; ATP-metabolism associated ecto-enzymes, such as NTPDase and NT5E, hydrolyze ATP to ADP, AMP and Ado; Both ADP and AMP activate P2YRs, and Ado activates P1Rs; In addition, NTs mediate the bidirectional diffusion of Ado between the cytoplasm and extracellular environment. UMAP, Uniform Manifold Approximation and Projection; Neu, neurons; Glia, glial cells; ICs, immune cells; FBs, fibroblasts; ECs, endothelial cells; ATP, adenosine triphosphate; P2XRs, P2X receptors; NTPDase, ectonucleoside triphosphate diphosphohydrolase; NT5E, Ecto-5’-nucleotidase; ADP, adenosine diphosphate; AMP, adenosine monophosphate; Ado, adenosine; P2YRs, P2Y receptors; P1Rs, P1 receptors; NTs, nucleoside transporters. SGC, Satellite glial cells.