Protective effect of tetramethylpyrazine on lipopolysaccharide-induced high permeability of human umbilical vein endothelial cells

ObjectiveTo investigate the effect of tetramethylpyrazine (TMP) on the permeability of human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS) and the expression of cytoskeleton-related proteins.

MethodsHUVECs cultured in vitro were randomly divide into normal control group, LPS group (1 μg/mL LPS), TMP low, medium and high dose group (60 μg/mL TMP+1 μg/mL LPS, 120 μg/mL TMP+1 μg/mL LPS, 240 μg/mL TMP+1 μg/mL LPS), pure TMP group (240 μg/mL TMP).Endothelial cell permeability model was established in Transwell chamber; cell voltage resistance meter was used to measure the trans-endothelial electrical resistance in each group; FITC-dextran method was used to detect the permeability change in each group, and Pull-Down experiment was used to collect Rac1-GTPase active protein, Western blotting was used to detect the protein expression of Rac1-GTPase, Rac1, LIMK1 and p-LIMK1 in each group.

ResultsTEER and permeability coefficient showed that three different concentrations of TMP inhibited the decrease of TEER induced by LPS in endothelial cells and decreased LPS-induced endothelial cell permeability(P < 0.05 to P < 0.01);Western blotting analysis showed that TMP could effectively inhibit the LPS-induced up-regulation of Rac1-GTPase, p-LIMK1, Rac1 and LIMK1 in HUVECs(P < 0.05 to P < 0.01).

ConclusionsTMP can effectively inhibit the increase of permeability of HUVECs induced by LPS, which may be related to the down-regulation of Rac1-GTPase active protein and LIMK1 phosphorylation protein expression in Rac1/LIMK1 signaling pathway.