Gal-9 attenuates pulmonary emphysema induced by PPE.

<p>Mice were given 2 units of PPE in saline or saline alone intratracheally on day 0. PPE- or saline-treated mice were further subdivided and treated subcutaneously with Gal-9 in PBS or PBS alone once a day from one day before PPE instillation to day 5. Lungs were resected on day 21 and stained with hematoxylin and eosin (H&E) for morphometric analysis. Emphysema was severe in PPE (+) Gal-9 (-) (C) compared to that in PPE (-) Gal-9 (-) (A) and PPE (-) Gal-9 (+) (B), and emphysema was attenuated in PPE (+) Gal-9 (+) (D). Scale bars = 200 μm. Lm was significantly increased in PPE (+) Gal-9 (-) (n = 6) compared to that in PPE (-) Gal-9 (-) (n = 5) and PPE (-) Gal-9 (+) (n = 5) and was significantly decreased in PPE (+) Gal-9 (+) (n = 10) compared to that in PPE (+) Gal-9 (-) (E, upper panel). The number of alveoli was significantly lower in PPE (+) Gal-9 (-) (n = 6) than in PPE (-) Gal-9 (-) (n = 5), and PPE (-) Gal-9 (+) (n = 5) and was significantly higher in PPE (+) Gal-9 (+) (n = 10) (E, lower panel). Data are presented as the mean ± SEM. *p < 0.05. Abbreviations: PPE, porcine pancreatic elastase; Gal-9, galectin-9; PBS, phosphate buffered saline; Lm, mean linear intercept; SEM, standard error of the mean.