BACKGROUND:A series of studies have found that mesenchymal stem cells play an important role in the prevention and cure of acute lung injury in adult animals.
OBJECTIVE:To further validate the effects of human umbilical cord mesenchymal stem cells on endotoxin-induced acute lung injury in newborn rats.
METHODS:Total y 120 newborn rats aged 7 days were randomly assigned to three groups. Intraperitoneal injection of 3 mg/kg endotoxin was done to establish neonatal rat model of acute lung injury in the model and stem cellgroup. Rats in the normal saline group were intraperitoneal y injected with 0.1 mL normal saline. After 30 minutes of modeling, the rats in the stem cellgroup were subjected to intraperitoneal injection of 0.1 mL human umbilical cord mesenchymal stem cells (1×106). The same volume of normal saline was administered in the normal saline and model groups. Lung tissue and blood specimens from newborn rats were taken at 6 hours, 1 day, 2 days, 4 days, and 7 days after treatment to observe lung pathological changes and detect levels of serum tumor necrosis factor-alpha and interleukin-10 as wel as myeloperoxidase activity in the lung tissue.
RESULTS AND CONCLUSION:The lung hematoxylin-eosin staining and myeloperoxidase activity indicated acute lung injury in the model group. At 4 and 7 days after modeling, the severity of lung injury in the stem cellgroup was lighter than that in the model group. Compared with the model group, the interleukin-10 level was significantly increased in the stem cellgroup, while the level of tumor necrosis factor-alpha was significantly reduced (P<0.05). These findings suggest that human umbilical cord mesenchymal stem cells transplanted into newborn rats with acute lung injury can reduce lung inflammation, and the main mechanism may be that human umbilical cord mesenchymal stem cells can balance anti-inflammatory and pro-inflammatory factors and reduce lung injury through immune regulation.