Project description:Human salivary gland organoids have opened tremendous possibilities for regenerative medicine in patients undergoing radiotherapy for the treatment of head and neck cancer. However, their clinical translation is greatly limited by the current use of Matrigel for organoid derivation and expansion. Here, we envisage that the use of a fully, synthetic hydrogel based on the oligo(-ethylene glycol) functionalized polymer polyisocyanopeptides (PICs) can provide an environment suitable for the generation and expansion of salivary gland organoids (SGOs) after optimization of PIC polymer properties. We demonstrate that PIC hydrogels decorated with the cell-binding peptide RGD allow SGO formation from salivary gland (SG)-derived stem cells. This self-renewal potential is preserved for only 4 passages. It was found that SGOs differentiated prematurely in PIC hydrogels affecting their self-renewal capacity. Similarly, SGOs show decreased expression of immediate early genes (IEGs) after culture in PIC hydrogels. Activation of multiple signalling pathways involved in IEG expression by β-adrenergic agonist isoproterenol, led to increased stem cell self-renewal capacity as measured by organoid forming efficiency (OFE). These results indicate that PIC hydrogels are promising 3D matrices for SGOs, with the option to be used clinically, after further optimization of the hydrogel and culture conditions.
Project description:Salivary glands produce saliva and play essential roles in digestion and oral health. Pluripotent stem cell-derived (PSC) organoids provide a powerful platform for studying salivary gland development and developing new regenerative therapy. The previous protocol of PSC-derived salivary gland organoids required complicated manufacturing processes, which hampered the organoids for basic research and clinical application.Here, by mimicking the regulatory mechanism of developing salivary glands, we reported the differentiation of induced embryonic salivary glands (iE-SGs) from mouse embryonic stem cells by step-wise treatment of retinoic acid and FGF10. We showed that the iE-SGs recapitulated early morphogenetic events, including the thickening and invagination of the salivary gland placode, and then formed initial buds. The iE-SGs also differentiated into developing ducts structures and could develop to striated and excretory ducts when transplanted in vivo. RNA- seq revealed that iE-SGs had gene expression profiles similar to mouse embryonic SMGs. Thus, our study provided an easy and safe method to generate iE-SGs and offered possibilities for studying events during salivary gland morphogenesis in vitro
Project description:Analysis of genes that are enriched in long-term self-renewing salivary gland stem cells. And analysis of genes that are enriched in the organoids containing differentiated salivary gland cells.
Project description:To identify transcription factors important for salivary gland organoids and associated to salivary gland stem/progenitor cells, we performed ATAC-seq of organoids derived from non-irradiated mice of different ages.
Project description:The immortalized normal human salivary gland ductal cells (NS-SV-DC) and acinar cells (NS-SV-AC) had characteristic morphologic differences, and useful for organizing knowledge of bio-functional mechanisms of human salivary gland.
Project description:The immortalized normal human salivary gland ductal cells (NS-SV-DC) and acinar cells (NS-SV-AC) have characteristic morphologic differences and useful for organizing knowledge of bio-functional mechanisms of human salivary gland.
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.