title: Human umbilical cord mesenchymal stem cells reduce systemic inflammation and attenuate LPS-induced acute lung injury in rats.
abstract: BACKGROUND
  Mesenchymal stem cells (MSCs) possess potent immunomodulatory properties and simultaneously lack the ability to illicit immune responses. Hence, MSCs have emerged as a promising candidate for cellular therapeutics for inflammatory diseases. Within the context of this study, we investigated whether human umbilical cord-derived mesenchymal stem cells (UC-MSCs) could ameliorate lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in a rat model.
  
  
  METHODS
  ALI was induced via injection of LPS. Rats were divided into three groups: (1) saline group(control), (2) LPS group, and (3) MSC + LPS group. The rats were sacrificed at 6, 24, and 48 hours after injection. Serum, bronchoalveolar lavage fluid (BALF), and lungs were collected for cytokine concentration measurements, assessment of lung injury, and histology.
  
  
  RESULTS
  UC-MSCs increased survival rate and suppressed LPS-induced increase of serum concentrations of pro-inflammatory mediators TNF-α, IL-1β, and IL-6 without decreasing the level of anti-inflammatory cytokine IL-10. The MSC + LPS group exhibited significant improvements in lung inflammation, injury, edema, lung wet/dry ratio, protein concentration, and neutrophil counts in the BALF, as well as improved myeloperoxidase (MPO) activity in the lung tissue. Furthermore, UC-MSCs decreased malondialdehyde (MDA) production and increased Heme Oxygenase-1 (HO-1) protein production and activity in the lung tissue.
  
  
  CONCLUSIONS
  UC-MSCs noticeably increased the survival rate of rats suffering from LPS-induced lung injury and significantly reduced systemic and pulmonary inflammation. Promoting anti-inflammatory homeostasis and reducing oxidative stress might be the therapeutic basis of UC-MSCs.
authors.affiliation: Department of Stomatology, Qilu Hospital, Shandong University, Ji'nan, Shandong, 250012, PR China. wfc.china@hotmail.com.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Liu
authors.forename: Shuhai
authors.initials: S
authors.lastname: Tang
authors.forename: Fengcai
authors.initials: F
authors.lastname: Wei