Umbilical cord-derived mesenchymal stem cells preferentially modulate macrophages to alleviate pulmonary fibrosis.

Background: Idiopathic Pulmonary Fibrosis (IPF) is a type of interstitial lung disease characterized by chronic inflammation due to persistent lung damage. Mesenchymal stem cells (MSCs), including those derived from the umbilical cord (UCMSCs) and placenta (PLMSCs), have been utilized in clinical trials for IPF treatment. However, the varying therapeutic effectiveness between these two MSC types remains unclear.

Methods: In this study, we examined the therapeutic differences between UCMSCs and PLMSCs in treating lung damage using a bleomycin (BLM)-induced pulmonary injury mouse model.

Results: We showed that UCMSCs had a superior therapeutic impact on lung damage compared to PLMSCs. Upon cytokine stimulation, UCMSCs expressed higher levels of inflammation-related genes and more effectively directed macrophage polarization towards the M2 phenotype than PLMSCs, both in vitro and in vivo. Furthermore, UCMSCs showed a preference for expressing CC motif ligation 2 (CCL2) and C-X-C motif chemokine ligand 1 (CXCL1) compared to PLMSCs. The expression of secreted phosphoprotein 1 (SPP1), triggering receptor expressed on myeloid cells 2 (Trem2), and CCAAT enhancer binding protein beta (Cebpb) in macrophages from mice with the disease treated with UCMSCs was significantly reduced compared to those treated with PLMSCs.

Conclusions: Therefore, UCMSCs demonstrated superior anti-fibrotic abilities in treating lung damage, potentially through inducing a more robust M2 polarization of macrophages than PLMSCs.