<i>Atg5^f/f;Aqp5-Cre</i> autophagy-deficient mice display increased hyperplasia and elevated compensatory proliferation of the parotid acinar cell population following targeted head and neck irradiation.

<p><i>Atg5^+/+;Aqp5-Cre</i> and <i>Atg5^f/f;Aqp5-Cre</i> (autophagy-deficient) mice were treated with a single 5-Gy dose of targeted head and neck radiation on day 0. At 24, 48, 72 hours and day 30 following treatment, salivary tissue was collected and serial sections were stained. Letters above treatment groups are used to signify statistical significance; treatment groups with the same letters are not significantly different from each other. Significant differences (<i>p</i><0.05) were determined using an ANOVA followed by a post-hoc Bonferroni multiple-comparison test. Data are presented as the mean ±SEM. <b>A.</b>) Representative image of H&E staining of unirradiated <i>Atg5^+/+;Aqp5-Cre</i> control-mice. <b>B.</b>) Representative image of H&E staining of <i>Atg5^f/f</i>;<i>Aqp5-Cre</i> unirradiated mice. <b>C.</b>) Representative image of H&E staining of irradiated <i>Atg5^+/+;Aqp5-Cre</i> mice 30 days after radiotherapy. <b>D.</b>) Representative image of H&E staining of irradiated <i>Atg5^f/f</i>;<i>Aqp5-Cre</i> mice 30 days after radiotherapy. <b>E.</b>) Total acinar cell counts taken from 3–5 images per mouse 30 days after radiotherapy. <i>p</i><0.05; n≥4 per genotype. UT: unirradiated. <b>F.</b>) Serial sections were stained for PCNA, a marker of proliferation, and the graph represents the number of acinar cells with positive PCNA staining in the parotid glands as a percentage of the total number of acinar cells. <i>p</i><0.05, n = 4 per genotype/per treatment. <b>G.</b>) Representative images of positive PCNA staining in the parotid glands.