Transcriptomic Mapping of Human Parotid Gland at Single-Cell Resolution

Abstract

As the largest salivary gland in oral cavity, the parotid gland plays an important role in initial digesting and lubricating food. The abnormal secretory function of the parotid gland can lead to dental caries and oral mucosal inflammation. In recent years, single-cell RNA sequencing (scRNA-seq) has been used to explore the heterogeneity and diversity of cells in various organs and tissues. However, the transcription profile of the human parotid gland at single-cell resolution has not been reported yet. In this study, we constructed the cell atlas of human parotid gland using the 10× Genomics platform. Characteristic gene analysis identified the biological functions of serous acinar cell populations in secreting digestive enzymes and antibacterial proteins. We revealed the specificity and similarity of the parotid gland compared to other digestive glands through comparative analyses of other published scRNA-seq data sets. We also identified the cell-specific expression of hub genes for Sjögren syndrome in the human parotid gland by integrating the results of genome-wide association studies and bulk RNA-seq, which highlighted the importance of immune cell dysfunction in parotid Sjögren syndrome pathogenesis.

Single‐cell RNA sequencing in oral science: Current awareness and perspectives

“…The scRNA-seq data of human parotid gland was compared with that of human minor salivary gland, other human digestive glands, and adult mice parotid gland. 58 As a result of scRNA-seq analysis, a comprehensive atlas of the heterogeneity of cell populations and expression profiles in salivary glands has been compiled. basal, mesenchymal, classical, and atypical.…”

“…126 In addition, combined genome-wide association studies (GWASs) and RNA-seq data for Sjogren's syndrome with human parotid gland scRNA-seq results, susceptibility genes in human parotid glands were identified. 58 Systemic lupus erythematosus (SLE), a type of chronic and even life-threatening autoimmune disease, is characterized by obscure pathogenesis and diverse manifestations. Oral discoid lesion is one of the most common SLE manifestations.…”

“…Combined scRNA‐seq with lineage tracing was used to identify transcription factors likely involved in acinar and ductal differentiation and characterize subsets of discrete cell types in anatomically defined glandular compartments 57 . In addition to constructing transcriptome maps of mouse salivary glands, scRNA‐seq also created transcriptome maps of human parotid gland 58 and minor salivary gland 59 from single‐cell perspective. The scRNA‐seq data of human parotid gland was compared with that of human minor salivary gland, other human digestive glands, and adult mice parotid gland 58 .…”

“…In addition to constructing transcriptome maps of mouse salivary glands, scRNA‐seq also created transcriptome maps of human parotid gland 58 and minor salivary gland 59 from single‐cell perspective. The scRNA‐seq data of human parotid gland was compared with that of human minor salivary gland, other human digestive glands, and adult mice parotid gland 58 . As a result of scRNA‐seq analysis, a comprehensive atlas of the heterogeneity of cell populations and expression profiles in salivary glands has been compiled.…”

“…The subsequent DEG and KEGG analysis demonstrated that affected acinar and ductal epithelial cell subpopulations may transition to a mixed epithelial/immune cell‐like state by aberrantly expressing molecules associated with immune cells 126 . In addition, combined genome‐wide association studies (GWASs) and RNA‐seq data for Sjogren's syndrome with human parotid gland scRNA‐seq results, susceptibility genes in human parotid glands were identified 58 …”