Heparin alleviates LPS‑induced endothelial injury by regulating the TLR4/MyD88 signaling pathway

Heparin is a commonly used in the clinic, however, Heparin's effect on endothelial injury remains unclear. The aim of the present study was to evaluate the effects and possible mechanisms of action underlying heparin treatment in lipopolysaccharide (LPS)-induced endothelial injury in vitro. TNF-[alpha], IL-1[beta], IL-6 and IFN-[gamma] levels were measured using ELISA. Cell proliferation was measured using a 5-ethynyl-2'-deoxyuridine (EdU) assay. The number of apoptotic cells and apoptotic rate were evaluated using TUNEL assays and flow cytometry, respectively. Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88) and NF-[kappa]B (p65) gene expression was evaluated using reverse transcription-quantitative PCR, whilst TLR4, MyD88 and p-NF-KB (p65) protein expression was evaluated using western blot analysis. The levels of phosphorylated NF-[kappa]B in the nucleus were evaluated using cellular immunofluorescence. Compared with those in the normal control group, TNF-[alpha], IL-1[beta], IL-6 and IFN-[gamma] levels were significantly increased in the LPS group (P