Orthotopic foetal lung tissue direct injection into lung showed a preventive effect against paraquat-induced acute lung injury in mice

OBJECTIVES Lung transplantation is the only effective therapy for patients with end-stage lung disease but an organ shortage crisis necessitates the development of alternative therapies. Recent studies have highlighted the potential of foetal tissue transplantation to facilitate the regeneration of vital organs such as liver that have been damaged by lethal diseases. Herein, with the aim of restoring pulmonary function, we hypothesized that allogenic foetal lung tissue implantation would attenuate severe respiratory failure. METHODS Lung tissue from the foetuses of pregnant green fluorescent protein-C57BL/6 mice at 13.5 days of gestation was injected into the left lungs of recipient mice. Severe lung injury was induced by paraquat, and we analysed the survival rate and pathohistological findings after 1 month. RESULTS The survival rate of the therapy group was 39%, which was significantly higher than the vehicle group at 5.9% (P = 0.034). Immunochemical staining showed that positive cytoplasmic stained cells with anti-interleukin-10 antibody were identified in the gland-like structure of embryonic day 13.5 foetal lung. At 4 weeks after orthotopic implantation, haematoxylin and eosin staining showed reduced lung inflammatory cells, reduced lung oedema and increased active cell proliferation of foetal lung cells. Lung injury score showed that the airway septal thickening revealed statistically significant differences between vehicle and foetal lung therapy (P < 0.001). CONCLUSIONS Immature foetal lungs improved the survival rate of mice with paraquat-induced severe lung injury, establishing the need for systematic follow-up studies. The anti-inflammatory cytokine in the tissue from embryonic day 13.5 foetal lung might suppress severe lung injury.