Cyclic helix B peptide ameliorated the sepsis-induced injury in human HPMEC cells through regulating NF-κB.

ABSTRACT

BACKGROUND: Sepsis is a life-threatening condition. The incidence of severe sepsis is increasing. Sepsis is often complicated with organ dysfunctions. Cyclic helix B peptide (CHBP) is a peptide derivant of erythropoietin with powerful tissue-protective efficacies. However, the role of CHBP in sepsis-induced injury remains unclear. MATERIAL AND METHODS: Lyso-phosphatidylserine (LPS) was used to induce sepsis in human pulmonary microvascular endothelial cells (HPMECs). Cell growth was detected using Cell Counting Kit-8. Cell permeability was measured using fluorescein isothiocyanate (FITC)-dextran. Cecal ligation and puncture (CLP) method was applied to induce sepsis and CHBP was provided to test its efficacy. Western blot assays were used to evaluate gene expression. RESULTS: Administration of CHBP ameliorated LPS-induced injury in HPMECs dose-dependently. Administration of CHBP decreased the permeability of LPS-treated HPMEC cells in a same way as well. Furthermore, we identified that recombinant CHBP protein (Re-CHBP) ameliorated CLP-induced injury in vivo. Finally, we found that administration of NF-κB activator, TNF-α, abolished the function of Re-CHBP in LPS-treated HPMEC cells. CONCLUSION: CHBP ameliorated sepsis-induced injury dose dependently both in vitro and in vivo through decreasing the permeability of HPMEC cells via suppressing NF-κB signaling and inflammation. Present findings highlight the importance of CHBP/NF-κB signaling in septic injury and provide new insights into therapeutic strategies for sepsis-induced injury.