To analyze the influence of Celastrol on lipopolysaccharide (LPS) -induced alveolar epithelial cell injury and the role of stromal cell-derived factor-1 (SDF-1) /chemokine receptor 4 (CXCR4) pathway in it.

Human alveolar type Ⅱ epithelial cell line A549 cells were cultured and treated with 10 μg/mL LPS for 24 h. Before LPS treatment, treat them with final concentrations of 25 mmol/L, 100 mmol/L of celastrol or 100 mmol/L of celastrol and 100 μg/L of AMD3100 (CXCR4 inhibitor) for 2 hours. The viability of A549 cells was determined by the CCK-8 method, apoptosis of A549 cells was measured by the TUNEL method, the LDH of A549 cells was determined by kits, the levels of tumor necrosis factor (TNF) -α, interleukin-6 (IL-6) and IL-10 in A549 cells were detected by ELISA, and the expression of SDF-1 and CXCR4 protein were as detected by Western blot. One-way analysis of variance was used for statistical comparison among multiple groups, and the SNK-q method was used for further pairwise statistical comparison.

Compared with the control group, the positive rate of TUNEL [ (65.78 ± 8.21) % vs (4.23 ± 0.77) %], the apoptosis rate [ (21.38 ± 2.70) %vs (7.64 ± 0.95) %], cleaved caspase-3, Bax protein, LDH, TNF-α, IL-6, SDF-1 (2.02 ± 0.25 vs 0.75 ± 0.10) , and CXCR4 (1.59 ± 0.19 vs 0.71 ± 0.08) protein were increased in A549 cells in LPS group (P < 0.05) , and the survival rate, Bcl-2 protein and IL-10 expression decreased (P < 0.05) ; compared with the LPS group, the positive rate of TUNEL [ (52.51 ± 6.54) %, (41.37 ± 5.17) %vs (65.78 ± 8.21) %], the apoptosis rate was [ (17.62 ± 2.45) %, (12.37 ± 1.54) %vs (21.38 ± 2.70) %], cleaved caspase-3, Bax protein, LDH, TNF-α, IL-6, SDF-1 (1.69 ± 0.20, 1.32 ± 0.18 vs 2.02 ± 0.25) , CXCR4 (1.31 ± 0.16, 1.05 ± 0.13 vs 1.59 ± 0.19) protein in A549 cells in the low-dose Celastrol group and high-dose Celastrol group significantly reduced, and the survival rate, Bcl-2 protein and IL-10 expression significantly increased (P < 0.05) ; compared with the high-dose Celastrol group, the positive rate of TUNEL[ (24.28 ± 4.28) %vs (41.37 ± 5.17) %], the apoptosis rate [ (9.91 ± 1.25) %vs (12.37 ± 1.54) %], and cleaved caspase-3, Bax protein, LDH, TNF-α, IL-6, SDF-1 (0.95 ± 0.13 vs 1.32 ± 0.18) , and CXCR4 (0.78 ± 0.09 vs 1.05 ± 0.13) protein of A549 cells in the high-dose Celastrol + AMD3100 group decreased, and the survival rate, Bcl-2 protein and IL-10 expression significantly increased (P < 0.05) .

Celastrol can reduce LPS-induced apoptosis and inflammation of A549 cells and improve cell survival, which may be related to the inhibition of the SDF-1/CXCR4 pathway.