FIGURE 5.

Limp-2^−/− mice exhibit reduced lamellar body PRDX6 and increased surfactant phospholipid pool sizes. A, representative immunoblots of LIMP2/SCARB2, PRDX6, SP-B, and GAPDH in total lung (LH), alveolar type 2 (AT2) cells, and lamellar body fractions (LB) from wild type (WT) and Limp-2^−/− mice (10 μg of total protein per lane). A light exposure of the SP-B immunoblot is presented as a loading control for lamellar body lanes; darker exposures demonstrate SP-B in lung homogenate and AT2 cell samples. B and C, total phospholipid, total phosphatidylcholine, and total DSPC were measured in total lung tissue (B) and bronchoalveolar lavage fluid from WT and Limp-2^−/− mice (C) (n = 4 mice of each genotype, mean ± S.E.). D, immunolocalization of PRDX6 in isolated alveolar type 2 cells (mAT2) from Limp-2^−/− mice and wild type littermates (WT) after depletion of cytosolic constituents, using LAMP1 immunostaining to identify lamellar bodies (representative of two experiments; bars represent 5 μm).