Cellular and signaling dynamics in lacrimal gland development

Abstract

The lacrimal gland (LG) is responsible for most tear production. Defective tear synthesis and secretion in the LG cause dry eye disease. This is a prevalent disease worldwide that causes eye irritation, and in severe cases, it can lead to eye damage. Understanding LG development is important for creating curative treatments for dry eye disease. Yet, cellular and signaling events during development remain partially uncharacterized. This review compiles an updated model of cell signaling, morphology, and cell lineage specification at each stage of LG development. These aspects of development are described together during presumptive bud formation, bud elongation, and branching. This review takes an innovative approach by further describing fetal and postnatal maturation in this model. Major signaling pathways in LG development are described and their recent characterization too. This review also highlights gaps in knowledge regarding cell heterogeneity, progenitor cells, and interspecies compatibility. In conclusion, this review describes cellular and signaling dynamics that coincide at each stage of LG development. Lastly, development and in vitro modeling are discussed to be of importance for guiding research to better understand LG physiology.