hucMSCs alleviate LPS-induced endothelial glycocalyx damage by secreting Cxcl12 to activate CXCR4

Acute respiratory distress syndrome (ARDS) has a high clinical mortality rate and continues to draw research attention regarding its mechanisms and potential treatments. Disruption of the endothelial barrier is a primary pathological feature, and glycocalyx degradation is a key factor contributing to this disruption. Human umbilical cord mesenchymal stem cells (hucMSCs) exhibit strong anti-inflammatory and immunomodulatory effects, making their application in ARDS treatment an area of increasing interest. Proteomic screening identified Cxcl12 as a protein secreted by hucMSCs. In male C57 mice and cell models, lipopolysaccharide (LPS) was used to induce injury, followed by interventions with hucMSCs or hucMSCs with silenced Cxcl12 to assess glycocalyx-related proteins SDC-1, HS, and the repair marker EXT-1. To evaluate downstream signaling, the CXCR4 receptor was inhibited and related indicators were examined. Silencing Cxcl12 reduced the therapeutic effect of hucMSCs on LPS-induced glycocalyx damage. Inhibition of CXCR4 also weakened the effect of Cxcl12. These findings indicate that hucMSCs alleviate LPS-induced glycocalyx damage in pulmonary vascular endothelial cells by secreting Cxcl12, which activates the downstream receptor CXCR4, providing a therapeutic effect for ARDS.