| Sepsis is a life-threatening multiple organ dysfunction caused by a dysregulated host response to infection.In the early stage of sepsis,the immune system is over-activated,and inflammatory factors are highly activated and released,which promotes the infiltration of leukocyte-based immune cells into tissues.Endothelial cells,as an effective protective barrier between blood and tissues,are highly activated during sepsis and work with other factors in organ impairment.Studies have shown that inhibition of endothelial inflammation can effectively attenuate sepsis-induced organ dysfunction.As sepsis usually needs to be differentiated from other diseases,sepsis diagnosis is often delayed and miss the best time for treatment.Despite significant advances in anti-infective treatment,the mortality rate of sepsis remains high,posing a huge threat to the public.Therefore,the mechanism of endothelium injury in sepsis can be further explored by comparing the correlation between the expression level of plasma inflammatory factors and the severity of sepsis in patients with early sepsis,which can also provide evidence for clinical diagnosis and treatment.Part Ⅰ.Expression of plasma cytokine pentraxin-3(PTX3),monocyte chemoattractant protein 1(MCP1)and angiopoietin 2(Ang2)in the early stage of septic patients.Backgruond:The paper aimed to detect the expression of plasma pentraxin-3(PTX3),monocyte chemoattractant protein 1(MCP1)and angiopoietin 2(Ang2)in the early stage of sepsis,and the correlations with the severity of sepsis and septic shock were observed.Methods:Patients in accord with the definition of sepsis were included and peripheral blood was collected within 24h after diagnosis.Healthy volunteers and post-surgery patients who were matched with sex and age were enrolled as control groups.Blood samples were centrifuged and stored at-80℃ before analysis.Circulating levels of inflammatory and immunity markers were measured in plasma samples by using Luminex techniques in parallel.The differences in these biomarkers between sepsis patients and different controls were compared and the correlation between cytokines and expression was analyzed.Results:The results showed that plasma PTX3,MCP1 and Ang2 were significantly upregulated in sepsis patients,especially in septic shock patients.Sepsis patients had significantly higher Ang2 level compared with controls.Furthermore,PTX3,MCP1 and Ang2 had large AUROC value in patients with sepsis and septic shock during the first day of sepsis onset.Conclusions:The findings suggest that increased PTX3,MCP1 and Ang2 expression might be early parameters for the prediction of the severity of sepsis and septic shock.Part Ⅱ.Metformin ameliorates endotoxemia-induced endothelial pro-inflammatory responses via AMPK-dependent mediation of HDAC5 and KLF2.Backgroud:To investigate the potential mechanisms of metformin on endothelial proinflammatory responses in sepsis.Methods:In vivo,LPS and TNF α were used to stimulate human umbilical vein endothelial cells(HUVEC).Western blot and Real-time PCR were used to detect the expression of mRNA and protein levels of p-AMPK,AMPK,p-HDAC5,HDAC5,KLF2 and VCAM1 under different stimulation or intervention conditions.Immunofluorescence experiments were used to locate nuclear translocation of HDAC5 in endothelial cells.Leukocyte adhesion assays were used to compare the functional status of endothelial cells under different stimulation or intervention conditions.T To investigate whether the anti-inflammatory effects were AMPK-dependent,observation of changes in HDAC5 and KLF2 after knockdown of AMPK using small interfering RNA(siRNA).In vivo,C57BL/6 mice were randomly divided into healthy control group,LPS group,metformin+LPS group,and AICAR+LPS group.The expression of VCAM1 in lung and kidney of different groups of mice was observed by immunohistochemistry.The levels of serum IL6 and TNFα of each group of mice were detected by ELISA.Results:Metformin pre-treatment diminished the increased VCAM1 expression and unregulated p-AMPK,pHDAC5 and KLF2 expression both in vitro and in vivo.The adhesion of HL60 leukocytes to endothelial monolayer was effectively inhibited by metformin.In addition,the in vivo data confirmed that AMPK activation attenuated local and systemic inflammation in endotoxic mice induced by LPS via mediating phosphorylating HDAC5 and restoring KLF2 expression.Conclusions:AMPK activator metformin effectively attenuates the inflammatory response of vascular endothelial cells induced by sepsis via AMPK-HDAC5KLF2 pathway. |
