Fig. 3

Long-term chronic exposure to PM2.5 damages LSPCs proliferation and differentiation abilities. (A) Anatomical structures of the limbus. (B) H&E staining showed thinner limbal epithelium suffered by long-term PM2.5 exposure on rat eyes (scale bar, 100 μm). N = 5 in each group. **p < 0.01. (C) Immunofluorescence staining showed the expression of proliferation marker Ki67 significantly decreased on rat limbus in the PM2.5 group (scale bar, 100 μm). N = 3 in each group. *p < 0.05. (D) K12 was markedly diminished in the PM2.5 group, which meant LSPCs differentiation was inhibited by PM2.5 (scale bar, 100 μm). N = 5 in each group. ****p < 0.0001. (E) PM2.5 group showed more K10 expression on the limbus, which implied limbus may have undergone abnormal differentiation under long-term PM2.5 stimulation (scale bar, 100 μm). N = 4 in each group. (F) The downregulated expression of Ki67, and K12 and abnormal expression of K10 indicated a loss of normal proliferation and differentiation function in LSPCs, which could lead to disruption of corneal epithelium homeostasis. PBS: the PBS eyedrop administration group; PM: the PM2.5 eyedrop administration group; LSPCs: Limbal stem/progenitor cells; K12: Keratin12; K10: Keratin10