Project description:Saliva aids in the predigestion of food and perception of taste. It helps to maintain the integrity of the mineralized tooth and epithelial surfaces in the mouth, and shields the oro-digestive tract from environmental hazards and invading pathogens. Although salivary glands and saliva fluid are biologically and functionally inseparable, they have thus far been investigated as separate entities. To bridge this gap, we performed an integrative analysis of the transcriptome of 27 samples collected from the major human adult and fetal major salivary glands - submandibular, sublingual, and parotid - along with mass-spectrometry-based saliva proteome data and immunohistochemical localization in glandular tissue. Our results suggest that functional maturation at the transcriptome level occurs late in gland development, and is driven mainly by the transcription of genes that code for secreted saliva proteins. We further provide evidence that protein dosage of the most abundant salivary proteins secreted by the salivary glands is predominantly regulated at the transcriptome level. Finally, we demonstrate distinct transcriptomic profiles of each major salivary gland type that reveal functional specialization and will aid in future clinical analyses. Our study provides the hitherto most comprehensive RNAseq dataset of healthy salivary glands in humans, thus establishing a robust framework for deeper studies of saliva and salivary gland biology, development, and evolution, ultimately paving the way for better understanding the importance of these craniofacial secretory organs in health and their malfunctions in disease.
Project description:Transcription factors drive organogenesis, from the initiation of cell fate decisions to the maintenance and implementation of these decisions. The Drosophila embryonic salivary gland provides an excellent platform for unraveling the underlying transcriptional networks of organ development because Drosophila is relatively unencumbered by significant genetic redundancy. The highly conserved FoxA family transcription factors are essential for various aspects of organogenesis in all animals that have been studied. Here, we explore the role of the single Drosophila FoxA protein Fork head (Fkh) in salivary gland organogenesis using two genome-wide strategies. A large-scale in situ hybridization analysis reveals a major role for Fkh in maintaining the salivary gland fate decision and controlling salivary gland physiological activity, in addition to its previously known roles in morphogenesis and survival. The majority of salivary gland genes (59%) are affected by fkh loss, mainly at later stages of salivary gland development. We show that global expression of Fkh cannot drive ectopic salivary gland formation. Thus, unlike the worm FoxA protein PHA-4, Fkh does not function to specify cell fate. In addition, Fkh only indirectly regulates many salivary gland genes, which is also distinct from the role of PHA-4 in organogenesis. Our microarray analyses reveal unexpected roles for Fkh in blocking terminal differentiation and in endoreduplication in the salivary gland and in other Fkh-expressing embryonic tissues. Overall, this study demonstrates an important role for Fkh in determining how an organ preserves its identity throughout development and provides an alternative paradigm for how FoxA proteins function in organogenesis. Three wild type (reference) samples were obtained from the Oregon R strain, age matched and treated the same as the three experimental samples isolated from Stage 11 fkh[6] mutant embryos.
Project description:To reveal novel molecular factors behind the development of salivary gland cancer, we performed gene expression analyses from Smgb-Tag mouse salivary gland samples. The overall purpose was to apply these results for clinical use to find new approaches for both possible therapeutic targets and more accurate diagnostic tools in identification of salivary gland cancers. Smgb-Tag mouse strain, in which salivary neoplasms arise through a dysplastic phase in submandibular glands, was investigated using genome-wide microarray expression analysis, Ingenuity pathway analysis, RT-PCR, and immunohistochemistry. 3 normal, 3 dysplastic, and 3 adenocarcinomatous submandibular gland tumours of Smgb-Tag mice.
Project description:Transcription factors drive organogenesis, from the initiation of cell fate decisions to the maintenance and implementation of these decisions. The Drosophila embryonic salivary gland provides an excellent platform for unraveling the underlying transcriptional networks of organ development because Drosophila is relatively unencumbered by significant genetic redundancy. The highly conserved FoxA family transcription factors are essential for various aspects of organogenesis in all animals that have been studied. Here, we explore the role of the single Drosophila FoxA protein Fork head (Fkh) in salivary gland organogenesis using two genome-wide strategies. A large-scale in situ hybridization analysis reveals a major role for Fkh in maintaining the salivary gland fate decision and controlling salivary gland physiological activity, in addition to its previously known roles in morphogenesis and survival. The majority of salivary gland genes (59%) are affected by fkh loss, mainly at later stages of salivary gland development. We show that global expression of Fkh cannot drive ectopic salivary gland formation. Thus, unlike the worm FoxA protein PHA-4, Fkh does not function to specify cell fate. In addition, Fkh only indirectly regulates many salivary gland genes, which is also distinct from the role of PHA-4 in organogenesis. Our microarray analyses reveal unexpected roles for Fkh in blocking terminal differentiation and in endoreduplication in the salivary gland and in other Fkh-expressing embryonic tissues. Overall, this study demonstrates an important role for Fkh in determining how an organ preserves its identity throughout development and provides an alternative paradigm for how FoxA proteins function in organogenesis.
Project description:To reveal novel molecular factors behind the development of salivary gland cancer, we performed gene expression analyses from Smgb-Tag mouse salivary gland samples. The overall purpose was to apply these results for clinical use to find new approaches for both possible therapeutic targets and more accurate diagnostic tools in identification of salivary gland cancers. Smgb-Tag mouse strain, in which salivary neoplasms arise through a dysplastic phase in submandibular glands, was investigated using genome-wide microarray expression analysis, Ingenuity pathway analysis, RT-PCR, and immunohistochemistry.
Project description:Rabies is a fatal zoonotic disease posing a threat to the public health globally. Rabies virus (RABV) is excreted in the saliva of infected animals, and is primarily transmitted through bite contact. Salivary glands play an important role for virus propagation. However, the significance of salivary glands is less studied in RABV pathogenic mechanisms. To identify functionally important genes in the salivary glands, we employed RNA sequencing (RNA-seq) to establish and analyze mRNA expression profiles in parotid tissue infected with two RABV strains, CVS-11 and PB4. We map the transcriptome changes in response to RABV infection in parotid tissue for the first time. This work provides new clues to the study of RABV-affected salivary gland function and RABV transmission mechanisms in parotid tissue. And the salivary gland-enriched transcripts could be potential targets of interest for rabies disease control.
Project description:By combining bulk RNA-seq and scRNA-seq approaches we have generated a comprehensive transcriptomic map of the murine parotid gland at different stages of maturation.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular functions. The goal of this study is to compare NGS-derived salivary gland transcriptome profilings (RNA-seq) to better understand the molecular nature of the physiological differences in adult murine salivary glands. Methods: Major murine salivary gland mRNA profiles were generated by deep sequencing, in triplicate, using Illumina HiSeq 2000. The sequence reads that passed quality filters were analyzed at the gene level with STAR followed by Cufflinks. In vivo NaCl reabsorption measurements were performed for validation. Results: Using an optimized data analysis workflow, we mapped about 15 million sequence reads per sample to the mouse genome (build mm10) and identified 1991 genes that were differentially expressed across three major salivary glands. RNA-seq data provided valuable insights into the nature of the functional differences among the major salivary glands Conclusions: Our study represents the first detailed analysis of murine salivary gland transcriptomes, with biologic replicates, generated by RNA-seq technology. Our results confirm functions of many genes, identified using genetically modified mice. We conclude that RNA-seq-based transcriptome characterization would offer a comprehensive and sensitive evaluation of the gene expression.