Unfractionated Heparin Reduces The Expression Of Adhesion Molecules Through HOXA9/NF-κB In Rats With Sepsis-induced Acute Lung Injury

Objective:Nuclear factor kappa B(NF-κB)is an important transcription factor in the development of sepsis-induced Acute lung injury(ALI),and its activation can lead to the occurrence of inflammatory cascade.Unfractionated heparin(UFH)plays an important role in anticoagulation and anti-inflammation in the treatment of sepsis,but its exact mechanism is still unknown.This study aims to investigate the changes in the expression of HOXA9/NF-κB(Homeobox A9)and E-selectin,ICAM-1(Intercellular cell adhesion molecule-1)in the lung tissue of cecal ligation and puncture(CLP)septic ALI rat model,and the therapeutic effect of UFH.Methods:This study used male SD rats as the research subjects and divided them into three groups: sham operation group,CLP group,and CLP+heparin group.The CLP group received only physiological saline at a dose of 30ml/kg for fluid resuscitation after CLP surgery.The CLP+heparin group received treatment with 200u/kg of UFH on the basis of CLP surgery and fluid resuscitation.The sham operation group received the same dose of physiological saline after surgery.After 12 hours of modeling,the rats were anesthetized and the lung tissue was taken for Hematoxylin and Eosin(HE)staining,and Real-Time Quantitative Polymerase Chain Reaction(q RT-PCR)was used to detect HOXA9,NF-κB,E-selectin,and ICAM-1 m RNA in lung tissue.Western blot was used to detect HOXA9,NF-κB,E-selectin,and ICAM-1 protein in lung tissue.In addition,the potential HOXA9 binding site in the NF-κB promoter was analyzed using Human TFDB.Results:1.HE staining results showed that the lung tissue of rats in the CLP group had obvious structural disorder,alveolar damage,edema,thickening of the interstitium,and extensive infiltration of inflammatory cells(P<0.0001),while the lung tissue damage in the CLP+heparin group was reduced(P<0.0001).2.q RT-PCR results showed that CLP caused a decrease in HOXA9 m RNA expression in rat lung tissue(P<0.001),and the expression of NF-κB(P<0.0001),E-selectin(P<0.001),and ICAM-1(P<0.0001)m RNA in the CLP group was significantly increased.UFH treatment reversed the effect of CLP on the target protein m RNA.3.Western blot results showed that CLP led to a decrease in HOXA9 protein content in mouse lung tissue(P<0.0001),and an increase in the expression of NF-κB(P<0.05),E-selectin(P<0.01),and ICAM-1(P<0.05)proteins.UFH reversed the changes in protein expression caused by CLP.4.Promoter analysis suggests the possible presence of HOXA9 binding sites upstream of the P65 and P105 subunit promoters of NF-κB in the human body.Conclusion: Our experiments verified that CLP caused lung tissue damage in rats,which could lead to a significant increase in the expression of adhesion molecules.UFH may reduce the expression of adhesion molecules in rat lung tissue caused by CLP through HOXA9/NF-κB pathway.