fig4

Figure 4. Multilevel therapeutic effects of MSC-EVs in dry eye disease: molecular, cellular, histological, and functional perspectives. DCs: Dendritic cells; ECM: extracellular matrix; EVs: extracellular vesicles; LFU: lacrimal functional unit; MMP-9: matrix metalloproteinase-9; MSC: mesenchymal stem cell; OSDI: ocular surface disease index; TIMP-1: tissue inhibitor of metalloproteinases-1; TIMP-2: tissue inhibitor of metalloproteinases-2; VEGF: vascular endothelial growth factor.