Fig. 6.

Macrophage SAMSN1 overexpression prevents LPS-induced ALI though activating AMPKα2 in vivo. (A) Human THP1 cells were stimulated with 100 ng/mL PMA for 48 h to differentiate into macrophages, and then cultured in fresh DMEM medium for 24 h, which were then infected with lentiviral vectors carrying shSamsn1 or Samsn1 at a MOI of 50 and 20 for 6 h, cultured for 48 h and stimulated with LPS (100 ng/mL) for an additional 12 h. Phospho-kinase array quantification was detected using a commercial kit. (B–C) Samsn1^MKO, Samsn1^MTG or control mice were intratracheally injected with LPS (5 mg/kg) and sacrificed after 12 h, and then AMPKα (T172) phosphorylation was detected in murine lungs. (D) Mice were injected with mannose-conjugated polymers-loaded siAmpkα2 or siScr at a dose of 2 mg/kg from the tail vain for 4 h, and then Ampkα2 mRNA level was detected in AMs isolated from siScr- or siAmpkα2-injected lungs. (E) Samsn1^WT or Samsn1^MTG mice were injected with mannose-conjugated polymers-loaded siAmpkα2 or siScr at a dose of 2 mg/kg from the tail vain for 4 h, and then were intratracheally injected with LPS (5 mg/kg). After 12 h, the levels of TNF-α and IL-6 in the lungs were detected. (F–G) The levels of ROS, MDA and 4-HNE. (H) LDH activity in the lungs. (I) Lung wet to dry ratio. (J) Tidal volume. (K–L) Blood gas analysis was determined by PaO₂, PaCO₂ and HCO₃⁻. (M) Protein concentrations in BALF. n = 6 per group, differences with P value < 0.05 were considered statistically significant.