Abstract
Presentation Description :
The organ germ method, which is a 3D tissue engineering technique to reconstitute a bioengineered organ germ, has been developed as a new strategy to progress the functional organ replacement regenerative therapy for severe organ dysfunction. The bioengineered lacrimal gland organ germ, which was generated using ED 16.5 mouse epithelial and mesenchymal cells obtained from the lacrimal gland germ, was able to reproduce the developmental process of the branching morphogenesis in organ culture. Our thread-guided 3D culture and transplantation technique enables the bioengineered lacrimal glands to induce the excretory duct structure from the epithelial cell aggregate and connect the induced duct with a recipient lacrimal gland excretory duct in a mouse. The engrafted bioengineered lacrimal gland could achieve the appropriate secretory gland architecture including a tubule-alveolar structure with tearing function, suggesting a future possibility of functional restoration of the lacrimal glands. The embryonic lacrimal gland epithelial cells shows the ability to develop into lacrimal gland epithelial lineages like acini and duct, however, their biological characters have been unknown. In our analysis, the expression of cytokeratin 15 was higher in the embryonic lacrimal gland epithelium than in the mature one. We further performed gene expression profiling by using microarrays with mouse tissues including embryonic and adult lacrimal glands and their developmental related organs to observe the specific regulatory gene expression during the lacrimal gland development. We identified 134 genes, which were specifically highly expressed in the embryonic lacrimal gland epithelium. Using previously published transcriptome data of various organs, we found a list of transcription factors, which are highly expressed in the embryonic lacrimal gland epithelium. Temporary overexpression of the combinations of the transcription factor with PAX6 using synthetic modified mRNAs in human ESC contributed the representative marker expressions of the the lacrimal gland epithelial development, suggesting the involvement of the gene expression network in the lacrimal gland developmental process. Further efforts that integrate developmental biology with gene expression analyses such as next-generation sequencing technologies would advance our understanding on regulatory gene expression networks for future lacrimal gland regeneration.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.