Study On The Effect Of Sodium Butyrate On The Permeability Of Vascular Endothelial Cells And Its Preliminary Mechanism After Severe Burn

Objective The purpose of this study was to investigate the effects of sodium butyrate on vascular permeability and endothelial glycocalyx of umbilical vein endothelial cells stimulated by serum from severely burned patients and its preliminary molecular mechanism.Methods1.According to the inclusion and exclusion criteria,the blood of 5 large area adult burn patients were recruited from the Burn Department of the High-tech Hospital of the first affiliated Hospital of Anhui Medical University,and 5 healthy adult blood were recruited to the society.the blood samples were collected immediately after centrifugation and numbering,and the serum was preserved.2.Umbilical vein endothelial cells(HUVECs)were divided into three stages:(1)HUVECs cultured with collected burn patient serum and healthy adult serum were divided into normal serum group,burn serum 12 h group and burn serum 24 h group.The expression of banded closure protein 1(ZO-1)m RNA was measured by q-PCR method,and the monolayer endothelial cell permeability coefficient(Pa)was measured by Transwell method.The changes of vascular permeability of endothelial cells were observed and the best stimulation phase was selected.(2)After HUVECs resuscitation,they were divided into four groups: normal serum group,burn serum group,low concentration sodium butyrate(SB)group and high concentration SB group.The expression of ZO-1 protein was measured by WB method,the shedding amount of vascular endothelial cadherin(VE-cadherin)and polyligand proteoglycan-1(SDC-1)in the cell supernatant was measured by ELISA method,the Pa value was measured by Transwell method,and the changes of endothelial glycocalyx.were observed under transmission electron microscope to explore the best dose of SB and its effect on endothelial cell vascular permeability and glycocalyx.(3)After HUVECs resuscitation,they were divided into four groups: normal serum group,burn serum group,burn serum+SB group and burn serum +SB+VEGF inhibitor group.The protein expressions of hypoxia inducible factor-1 α(HIF-1 α),vascular endothelial growth factor(VEGF)and matrix metalloproteinase-9(MMP-9)in HUVECs were detected by WB.Results1.The expression of ZO-1m RNA in burn serum group was significantly lower than that in normal serum group(P < 0.0001),and the expression of ZO-1m RNA in 12 h group was lower than that in 24 h group(P< 0.0001),the Pa value in burn serum stimulated HUVECs group was significantly higher than that in normal serum group(P<0.0001),but there was no significant difference between burn serum 12 h group and burn serum 24 h group(P > 0.05).2.The expression of ZO-1 protein in high concentration SB group was significantly higher than that in burn serum group,but there was no significant difference between low concentration SB group and burn serum group and high concentration SB group(P > 0.05).The level of VE-cadherin in the supernatant of burn serum group was significantly higher than that in normal serum group.The level of VE-cadherin in high concentration SB group was significantly lower than that in burn serum group and low concentration SB group.However,there was no significant difference in VE-cadherin level between low concentration SB group and burn serum group.The Pa value of high concentration SB group and low concentration SB group was lower than that of burn serum group,and the Pa value of high concentration SB group was lower than that of low concentration SB group(P < 0.05).The amount of SDC-1 shedding in burn serum group was significantly higher than that in normal serum group,the amount of SDC-1 shedding in low concentration SB group and high concentration SB group was significantly lower than that in burn serum group,and the amount of SDC-1 shedding in high concentration SB group was lower than that in low concentration SB group.Compared with burn serum group,the saccharocalyx layer of burn serum + SB group was thicker and the degree of structural damage was slighter,especially in 3mmol/L group.3.The protein expression of HIF-1 α,VEGF and MMP-9in the burn serum group was significantly higher than that in the normal serum group,while the protein expression of HIF-1α,VEGF and MMP-9 in the burn serum + SB group was significantly lower than that in the burn serum group,but still higher than that in the normal serum group.The protein expression of VEGF and MMP-9 in burn serum + SB + VEGF inhibitor group was significantly lower than that in burn serum group and burn serum + SB group.ConclusionSodium butyrate attenuates the injury of vascular endothelial glycocalyx after severe burn by inhibiting the activation of HIF-1α/VEGF/MMP-9 signal pathway,thus improving the increase of vascular endothelial cell permeability caused by severe burn.