Project description:Although mesenchyme is essential for inducing the epithelium of ectodermal organs, its precise role in organ-specific epithelial fate determination remains poorly understood. To elucidate roles of tissue interactions in cellular differentiation, we performed single cell RNA sequencing and imaging analyses of recombined tissues in which embryonic mouse salivary gland mesenchyme and epithelium were switched ex vivo. We found partial induction of molecules that define gland-specific acinar and myoepithelial cells in recombined salivary epithelium. Parotid epithelium (serous gland) recombined with submandibular mesenchyme (mixed serous-mucous, but predominantly mucous gland) began to express mucous acinar genes not intrinsic to the parotid gland. While myoepithelial cells do not normally line parotid acini, newly induced myoepithelial cells densely populated recombined parotid acini. However, mucous acinar and myoepithelial markers continued to be expressed in submandibular epithelial cells recombined with parotid mesenchyme. Consequently, some epithelial cells appeared to be plastic, such that their fate could still be altered in response to mesenchymal signaling, whereas other epithelial cells appeared to be already committed to a specific fate. We also discovered evidence for bidirectional induction: transcriptional changes were observed not only in the epithelium but also in the mesenchyme after heterotypic tissue recombination. For example, parotid epithelium induced the expression of muscle-related genes in submandibular fibroblasts that began to mimic parotid fibroblast gene expression. These studies provide the first comprehensive unbiased molecular characterization of tissue recombination approaches exploring the regulation of cell fate.
Project description:Although mesenchyme is essential for inducing the epithelium of ectodermal organs, its precise role in organ-specific epithelial fate determination remains poorly understood. To elucidate roles of tissue interactions in cellular differentiation, we performed single cell RNA sequencing and imaging analyses of recombined tissues in which embryonic mouse salivary gland mesenchyme and epithelium were switched ex vivo. We found partial induction of molecules that define gland-specific acinar and myoepithelial cells in recombined salivary epithelium. Parotid epithelium (serous gland) recombined with submandibular mesenchyme (mixed serous-mucous, but predominantly mucous gland) began to express mucous acinar genes not intrinsic to the parotid gland. While myoepithelial cells do not normally line parotid acini, newly induced myoepithelial cells densely populated recombined parotid acini. However, mucous acinar and myoepithelial markers continued to be expressed in submandibular epithelial cells recombined with parotid mesenchyme. Consequently, some epithelial cells appeared to be plastic, such that their fate could still be altered in response to mesenchymal signaling, whereas other epithelial cells appeared to be already committed to a specific fate. We also discovered evidence for bidirectional induction: transcriptional changes were observed not only in the epithelium but also in the mesenchyme after heterotypic tissue recombination. For example, parotid epithelium induced the expression of muscle-related genes in submandibular fibroblasts that began to mimic parotid fibroblast gene expression. These studies provide the first comprehensive unbiased molecular characterization of tissue recombination approaches exploring the regulation of cell fate.
Project description:Salivary glands that produce and secret saliva, which is essential for lubrication, digestion, immunity, and oral homeostasis, consist of diverse cells. The long-term maintenance of diverse salivary gland cells in organoids remains problematic. Here, we established long-term murine salivary gland organoids from 3 major salivary glands, including parotid gland (PG), submandibular gland (SMG), and sublingual gland (SLG). Murine salivary gland organoids expressed gland-specific genes and proteins of acinar, myoepithelial, and duct cells. Organoids were maintained in growth media (named GEM) and further underwent differentiation in differentiation media (named DAM). Our study will provide an experimental platform for the exploration of mechanisms involvled in tissue regeneration, development, or several salivary gland diseases.
Project description:Loss of Irf6 leads to disruption of branching morphogenesis and secretory acnii formation in salivary gland. To determine the differentially expressed genes in Irf6 mutant, embryonic salivary gland tissues were extracted at E14.5.
Project description:Ionizing radiation (IR) – induced salivary gland damage is a common adverse effect in radiotherapy for patients with head and neck cancers. Currently, there is no effective treatment for the resulting salivary gland hypofunction and xerostomia (dry mouth). Here we profiled the acute gene expression change in the mouse submandibular salivary gland, and defined its damage response patterns at the transcriptome level.
Project description:Salivary glands that produce and secret saliva, which is essential for lubrication, digestion, immunity, and oral homeostasis, consist of diverse cells. Maintenance of diverse salivary gland cells in organoids remains problematic. Here, we established human salivary gland organoids, which is composed of multiple cellular subsets, from 3 major salivary glands, including parotid gland (PG), submandibular gland (SMG), and sublingual gland (SLG). Human salivary gland organoids expressed gland-specific genes and proteins of acinar, myoepithelial, and duct cells. Organoids were maintained in growth media (named GEM) and further underwent differentiation in differentiation media (named DAM). Our study will provide an experimental platform for the exploration of mechanisms involvled in tissue regeneration, development, or several salivary gland diseases.
Project description:Tumors of the major and minor salivary gland encompass a diverse spectrum of diagnostically challenging neoplasms. Recent studies have identified several gene fusions and somatic mutations that are specific or highly enriched in certain salivary gland tumor entities and can assist histopathological diagnosis. Still, there is an unmet need to identify additional diagnostic biomarkers for entities lacking specific alterations. In this study, we collected a comprehensive cohort of 363 cases encompassing 20 different salivary gland tumor entities and explored the potential of DNA methylation to classify these tumors. We were able to show that most entities show specific epigenetic signatures and present a machine learning algorithm that can be used to classify diagnostically challenging cases.