Figure 2.

STIMATE^sftpc-deficient mice exhibit aseptic spontaneous pulmonary injury and fibrosis. (A) The concentration of STIMATE⁺ exosomes in the BALF of WT or STIMATE^sftpc mice of different ages was detected by Exo-based ELISA (n = 6). (B) H&E staining of paraffin-embedded lung sections from newborn and 24-week-old WT or STIMATE^sftpc mice, 400× magnification (n = 6), left lung. (C) Plot data based on D-lactic acid and L-lactic acid accumulation in the BALF of WT or STIMATE^sftpc mice, n = 6. (D) Plot data based on the respiratory system compliance of WT or STIMATE^sftpc mice (n = 6). (E) Plot data based on hydroxyproline accumulation in the BALF of WT or STIMATE^sftpc mice (n = 6). (F) Plot data based on the ratio of M1-like to M2-like TRAMs in the BALF of WT or STIMATE^sftpc mice (n = 6). (G) In vitro monitoring of mitochondrial respiration in TRAMs in the BALF of WT or STIMATE^sftpc mice, (n = 6). (H) In vitro test of glycolysis capacity in TRAMs in the BALF of WT or STIMATE^sftpc mice (n = 6). GR: glycolytic reserve. (I)① Schematic diagram of the generation of BM chimeric mice. Lethally irradiated STIMAT-deficient CD45.2⁺ mice received BM transplantation from WT CD45.1⁺ mice, and their TRAMs were mainly derived from Flt3⁺CD45.1⁺ myeloid cells. ② Similarly, TRAMs of recipient CD45.1⁺ WT BM chimeric mice were mainly derived from peripheral Flt3⁺ monocytes of STIMAT^sftpc CD45.2 donor mice. (J) The sorting strategy of CD45.1⁺FLT3⁺M1-like TRAMs in type ① BM chimeric mice. The right panel shows data based on CD45.1⁺FLT3⁺M1-like TRAMs in the lungs of BM chimeric mice (n = 5), and CD45.1 +WT donor mice served as controls (n = 5). (K) The sorting strategy of CD45.2⁺FLT3⁺M2-like TRAMs in type ② BM chimeric mice (n = 5),, and CD45.2⁺ STIMAT^sftpc donor mice served as controls (n = 5). (L and M) Seahorse monitoring of mitochondrial respiration CD45.1⁺FLT3⁺ M1-like and CD45.2⁺FLT3⁺ M2-like TRAMs in type ① and type ② BM chimeric mice, respectively (n = 5). Data are shown as the mean ± SD, *p < 0.05 and **p < 0.01 by Student's t test, analysis of variance (ANOVA) followed by a post hoc test. All cell experiment data were derived from 3 independent experiments.