[Endothelial cells and fibroblasts mediate the microenvironmental regulatory network of carotid body paraganglioma].

<b>Objective:</b>To explore the gene expression characteristics of endothelial cells and fibroblasts in the microenvironment of <i>SDHD</i>-mutated carotid body tumors（<i>SDHD</i>-CBT）, to fine the functional enrichment of each subcluster, and to further explore the network of cell-cell interactions in the microenvironment of <i>SDHD</i>-CBT. <b>Methods:</b>The bioinformatics analysis was used to download and reanalyze the single-nuclear RNA sequencing data of <i>SDHD</i>-CBT, <i>SDHB</i> mutated thoracic and abdominal paraganglioma（<i>SDHB</i>-ATPGL）, <i>SDHB</i>-CBT, and normal adrenal medulla（NAM）, to clarify the information of cell populations of the samples. We focused on exploring the gene expression profiles of endothelial cells and fibroblasts subclusters, and performed functional enrichment analysis based on Gene Ontology（GO） resources. CellChat was used to compare the cell-cell interactions networks of different clinical samples and predict significant signaling pathways in <i>SDHD</i>-CBT. <b>Results:</b>A total of 7 cell populations were profiled. The main subtypes of endothelial cells in <i>SDHD</i>-CBT are arterial and venous endothelial cells, and the main subtypes of fibroblasts are myofibroblasts and pericytes. Compared to NAM, <i>SDHB</i>-CBT and <i>SDHB</i>-ATPGL, cell communication involving endothelial cells and fibroblasts in <i>SDHD</i>-CBT is more abundant, with significant enrichment in pathways such as FGF, PTN, WNT, PROS, PERIOSTIN, and TGFb. <b>Conclusion:</b>Endothelial cells and fibroblasts in <i>SDHD</i>-CBT are heterogeneous and involved in important cellular interactionprocesses, in which the discovery of FGF，PTN，WNT，PROS，PERIOSTIN and TGFb signals may play an important role in the regulation of microenvironment of <i>SDHD</i>-CBT.