BACKGROUND: Studies have shown that exogenous bone marrow mesenchymal stem cells can settle down in lung tissue, participate in long regeneration, but few studies concerned the repair of aging lung injury.
OBJECTIVE: To observe the effect of bone marrow mesenchymal stem cells on lung injury induced by D-galactose.
METHODS: A total of 30 Sprague-Dawley rats were equally divided into three groups at random: control group, aging model group and cell treatment group. To establish the aging rats, 10 rats each in the aging model group and cell treatment group were daily subcutaneously injected with D-galactose for 4 months. 3×106 bone marrow mesenchymal stem cells were transplanted via caudal vein in the cell treatment group, once a week, for 4 weeks. Cell medium of equal dose was added in the control and aging model groups. Bone marrow mesenchymal stem cells were transfected by lentiviral vectors expressing green fluorescent protein to determine the implantation of bone marrow mesenchymal stem cells in rat lung. Superoxide dismutase activity and malondialdehyde content in rat lung were measured in each group. The difference in rat lung structure was observed using hematoxylin-eosin staining in each group.
RESULTS AND CONCLUSION: Bone marrow mesenchymal stem cells marked by green fluorescent protein were implanted in rats, migrated towards lung tissue and survived. Compared with aging model group, superoxide dismutase activity was apparently increased, but malondialdehyde content was obviously diminished in the cell treatment group. In each group, histopathological sections revealed that normal pulmonary alveolus was damaged in the aging model group, showing enlarged air cavity and emphysema. Lung injury was evidently repaired inthe cell treatment group. Results suggested that bone marrow mesenchymal stem cells could repair lung injury in aging rats, and exert anti-aging effects.