Indinavir Ameliorates Glucocorticoid Deficiency And Its Mechanism Of Anti-inflammatory In Experimental ARDS

Background and Purpose:Unusual high mobility group box 1(HMGB1)activation releases and activates many inflammatory factors,leading to an aggregating inflammatory cells around lungs and an injury on airway epithelium.Thus it has a key part in the pathogenesis of acute respiratory distress syndrome(ARDS).Glucocorticoid exerts its anti-inflammatory action in ARDS.However,sensitivity to glucocorticoid can decline with long-term use.In order to solve the occurred glucocorticoid receptor(GR)deficiency in ARDS,indinavir,a cure for AIDS,is selected for mitigate this problem.Methods:This paper consists two parts.In the first part,LPS was used to stimulate HMGB1 into activation;Western Blot was used to test the protein level of HMGB1,TLR-4,NF-κB,RAGE and aquaporins 5;BAY 11-7084 inhibitor for NF-κB and siRNA of HMGB1 were performed to reveal the mechanism of indinavir in pulmonary microvascular endothelial cells(HPMECs);On the other hand,the ARDS model of rat was induced by lipopolysaccharide "two-hit";The distribution of aquaporins 5 and HMGB0/TLR-4/NF-κB in rat lung tissues were tested by Western Blot and immunohistochemical,respectively,which illuminated the therapeutic effect of indinavir on ARDS.In the second part,LPS was incorporated with methylprednisolone to induce the GR deficiency ARDS rat model;The pathological change was detected by hematoxylin eosin stain and histology of the lung tissues was scored;Western Blot was used to test the protein level of GR-α、IκB-α、HMGB1 and p-NF-KB.This part investigated the treatment effect of indinavir on polysaccharide and methylprednisolone-induced the GR deficiency in vivo and in vitro.Key Results:Indinavir treatment gave rise to a reduction in HMGB1,its receptor toll-like receptor 4(TLR-4),and HMGBI’s downstream phosphorylated NF-κB,increase of vascular endothelial cadherin(VE-cadherin).AT I injury was weakened with a rise in the number of receptors for advanced glycation end products(RAGE)and Aquaporin 5.Compared to methylprednisolone,Methylprednisolone plus Indinavir attenuated the decrease of glucocorticoid receptor alpha(GR-a)and IKB-α in cytoplasm of LPS stimulated HPMECs for 96 hours,attenuated the increase of phosphorylated NF-κB in nucleus.Indinavir ameliorated LPS-induced two-hot ARDS in rats with reductions in microvascular permeability,histopathological scores and lower HMGB1,TLR4,and phosphorylated NF-κB expression whereas higher RAGE,Aquaporin 5 and VE-cadherin were noted in LPS-instilled lungs.Compared to methylprednisolone,Methylprednisolone plus Indinavir increased GR-a and IKB-a in cytoplasm,decreased phosphorylated NF-κB in nucleus of lung tissue of two-hot ARDS rats.Conclusions:It demonstrated that indinavir prevents experimental ARDS with GR deficiency by modulating the HMGB1/TLR-4 pathway to resolve pulmonary inflammation response,avoid glucocorticoid resistance in ARDS treatment with glucocorticoids.