Optimized administration of human embryonic stem cell-derived immunity-and-matrix regulatory cells for mouse lung injury and fibrosis.

BACKGROUND: Lung injury and pulmonary fibrosis (PF), frequently arising as sequelae of severe and acute lung disease, currently face a dearth of effective therapeutic potions. Mesenchymal stem cells (MSCs) with immunomodulatory and tissue repair functions have immense potential to treat lung injury and PF. However, the optimal route of administration, timing, and frequency of dosing remain elusive. Human embryonic stem cell-derived immunity-and-matrix-regulatory cells (IMRCs) have shown therapeutic potential for lung injury and PF. METHODS: To ascertain the optimal therapeutic regimen for IMRCs in PF, we conducted an experimental study. Utilizing a mouse model of PF induced by bleomycin (BLM), IMRCs were administered via either a single or double intravenous (IV) or intratracheal (IT) injection on the first and seventh days post-BLM induction. RESULTS: Our findings revealed that IV infusion of IMRCs surpassed IT infusion in enhancing survival rates, facilitating body weight recovery, and optimizing Ashcroft and Szapiel scores among the model mice. Notably, IV administration exhibited a more profound ability to mitigate lung inflammation and fibrosis. Moreover, earlier and more frequent administrations of IMRCs were found to be advantageous in enhancing their therapeutic effects. Specifically, early administration with two IV infusions significantly improved body weight, lung organ coefficient, pulmonary ventilation and diffusion functions, and PF. This was accompanied by an increase in alveolar type I and II epithelial cells and a suppression of macrophage infiltration via CD24. CONCLUSION: Collectively, these results suggested that IMRCs infusion ameliorated lung injury by promoting lung regeneration and inhibiting macrophage infiltration in a route, time, and frequency-dependent manner.