(A) Endotoxin level of rat blood was assessed using an endotoxin detection kit 12 h after the CLP model was established (n=4, from four individuals). (B) The wet and dry weight (24 h) of the left lower lung was recorded and calculated for the wet/dry ratio (n=4, from four individuals). (C) Representative H&E staining of lung tissue under microscopy observation. The images are representative of four individuals. (D) Observation of CLP rat lung by electron microscopy. The images are representative of four individuals. (E–G) Western blotting analysis of active-casp3, Bcl-2, and Bax expression in the lung tissue of the CLP model, and β-actin served as an internal reference. The blots are representative of at least three independent experiments with similar results. (H) Exosomes were extracted from the plasma of sham and CLP rats by precipitation and then subjected to miRNA sequencing. KEGG analysis of the top 20 most significantly different miRNAs’ pathways. (I) MiR-1-3p was significantly expressed in the sequencing of CLP plasma-derived exosomes (CLP-Exo) (n=3, from three independent experiments). (J,K) RT-PCR to confirm the expression of miR-1-3p in CLP rats and sepsis patients’ (n=3, from three independent experiments) plasma-derived exosomes. (L) RT-PCR test of miR-1-3p expression in lung tissue of CLP rat (n=4, from four independent experiments). (M) RT-PCR test of miR-1-3p expression in the lung tissue of LPS administrated rat (n=4, from four independent experiments). (N) RT-PCR test of miR-1-3p expression in the intestine of CLP rat (n=4, from four independent experiments). (O) MiR-1-3p expression in Sham-Exo and CLP-Exo (precipitated from 50 μl of plasma) treated HUVECs for 24 h by RT-PCR (n=4, from four independent experiments). Data are presented as mean ± SE, *P<0.05. Abbreviation: RT-PCR, real-time polymerase chain reaction.