In Vivo Imaging Reveals Exosome-Mediated Intercellular Communication in Lens Development
The transparency of lens relies on proper intercellular communication. Exosomes are crucial mediators of intercellular communication and play a key role in organ homeostasis and development. However, their presence and dynamics in the lens remain unclear. This study aimed to investigate the existence of endogenous exosomes in the lens and explore their potential functions. Using the cryaa promoter to drive Cd63-AcGFP expression, we achieved lens-specific exosome labeling in zebrafish.  Live imaging revealed the presence of exosomes in lens cells during development and their movement trajectory under physiological conditions. Additionally, lens-derived exosomes (lens-Exos) facilitate communication not only between lens cells but also with surrounding tissues. We also identified that the biogenesis of Cd63+ exosomes in the lens is regulated by the Syntenin-a pathway. As knockdown of Syntenin-a in zebrafish resulted in delayed lens development, indicating a potential role for exosomes in normal lens development. Furthermore, in vitro hESC-lentoid induction showed that extracellular vesicles from ROR1+ lens progenitor cells (ROR1+ LPCs-EVs) promote lentoid differentiation. Proteomic analysis provided insights into the functions of ROR1+ LPCs-EVs. Overall, our study is the first to observe endogenous exosomes in the lens, providing new insights into lens pathophysiology and a potential strategy for modulating the lens microenvironment. Overall design: ROR1+ cells were magnetically isolated at D30 from hESC-derived lentoid bodies induction system, and RNA-seq was performed on three biological replicates (Passage 0) for transcriptome profiling.