Effect of transplantation of endothelial progenitor cells on inflammatory responses during oleic acid-induced acute lung injury in rabbits

Abstract

Objective To evaluate the effects of transplantation of endothelial progenitor cells (EPCs) on inflanmatory responses during acute lung injury (ALI) induced by oleic acid in rabbits.Methods Ninety-six New Zealand male rabbits,aged 7-10 months,weighing 2.5-3.0 kg,were randomly divided into 4 groups using a random number table:control group (group C,n =16),transplantation of EPC group (group EPC,n =32),ALI group and ALI + transplantation of EPC group (group ALI + EPC,n =32).ALI was induced by iv 20％ emulsified oleic acid 75 mg/kg.EPCs (106 cells,in 1 ml of PBS) or the equal volume of PBS was administered intravenously at 0.5 h after iv oleic acid injection.Eight animals were randomly chosen at 6,12,24 and 48 h after oleic acid injection (T1-4) in LI and ALI+ EPC groups,or at T3,4 in C and EPC groups,and then sacrificed.The lungs were removed for determination of the expression of NF-κB mRNA (by RT-PCR),TNF-α,IL-1β and activity of NF-κB (by Western blot),and for microscopic examination of pathological changes of lung tissues (using HE staining).Diffuse alveolar damage (DAD) score was carried out.Results Compared with group C,the expression of NF-κB mRNA,IL-1β and TNF-α was significantly up-regulated,and NF-κB activity and DAD score were increased at T3,4 in ALI and ALI + EPC groups,and no significant change was found in the parameters mentioned above in EPC group.Compared with ALI group,the expression of NF-κB mRNA,TNF-α and IL-1β was significantly down-regulated,and NF-κB activity and DAD score were decreased at T1-4 in ALI + EPC group.Conclusion The mechanism by which EPCs mitigate ALI induced by oleic acid is related to inhibition of inflammatory responses in rabbits. Key words: Endothelial cells; Stem cell transplantation ; Respiratory distress syndrome, adult; Oleic acid; Inflammation