Expression Of CD200and CD200R In The Rat Lung Of Acute Lung Injury Induced By Sepsis

Objective:To study the expression of CD200and CD200R in the lung of acute lung injuryinduced by sepsis.Methods:Acute lung injury (ALI) rat model was established by cecum ligation and puncture.Thirty-six adult Wistar rats were randomly divided into sepsis induced ALI group (n=18)and control group (n=18). Rats of each group were sacrificed at8h，16h，24hours,respectively, after injury. Blood was collected from the abdominal artery blood gasanalysis was conducted. The pathological changes and wet to dry weight ration of the lungtissue were observed. Additionally, the concentration of plasma IL-4was detected byELISA and the expression of CD200and CD200R at the mRNA level and protein level inlung tissue was measured by RT-PCR and Western blotting, respectively.Results:Compared with controls, expression of CD200and CD200R of ALI rats wassignificantly reduced at8h and16h after injury both at the mRNA level and protein level(P<0.05). while increased to the control expression level at24h. The blood oxygen pressurebegan to decrease at16h after injury (P<0.05) and reached the lowest level at24h (P<0.05).The IL-4concentration and wet to dry weight ration were both evaluated at16h after injury(P<0.05) and last to24h after injury (P<0.05). With the ALI progressing, the pathologicalstructure of the lung tissue were changed more obviously.Conclusion:The mRNA and protein expression of CD200and CD200R level have a significantlydicline at8h and16h; this dicline was gradually stopped and expression restored at24hafter injury; IL-4has a postive role in regular CD200R expression. CD200/CD200R might be involved in the development of ALI through attenuating of inflammatory response andrecovering the balance between pro-inflammatory and anti-inflammatory.