Figure 6.
After LG Injury, MECs Repair the Acinar Epithelial Component
(A) Experimental design diagram. In the injury experiments we used females because dry eye disease is prevalent in females and LGs in females are smaller, ensuring a significant LG damage (also see Figure S7). The SMACreERT2:Rosa26-tdTomato female mice were injected with TM for three consecutive days (at P28–P30 or P58–P60) to label MECs, and 10 days later the LGs on one side of the animal were injured by IL-1α, whereas LGs on the other side of the animal were injected with saline (vehicle control). At least two to four independent experiments were performed at each stage. Mice were sacrificed 2 weeks later, and LGs were processed for frozen section preparation, immunostaining, and analysis: P28–P55: two independent experiments, 6 mice; 6 control and 6 IL-1α-injected LGs were studied; P58–P85: four independent experiments, 12 mice, 12 control and 12 IL-1α-injected LGs were analyzed.
(B–E) (B and C) In control (saline-injected) LG MECs retain an MEC phenotype and do not give rise to any other cell types, whereas after LG acute injury with IL-1α (D and E) a subset of MECs could acquire different fate and contribute to the acinar compartment of the LG.
(F) Cell quantification for each condition in each experiment (control or injured) was performed in sections (5 random sections per gland with 5–7 fields per section were analyzed).Total number of labeled cells in each gland were considered 100%; acinar cells were immunostained with the Panx1 antibody (acinar and ductal marker in adult mice) and percentage of labeled acinar cells has been determined. ∗P28–P55: two-tailed t test n = 6, p < 0.001 two-tailed t test; ∗∗P58–P85: n = 12, p < 0.0001, two-tailed t test. All results show mean ± SD. See also Figure S7.