Expression levels and significance of PAI-1 and TLR4 in hypertrophic scar tissue after burn
Objective To investigate the expression levels and clinical significance of plasminogen activator inhibitor-1(PAI-1)and Toll-like receptor 4(TLR4)in hypertrophic scar(HS)tissue after burn.Methods Ninety-four patients with HS who were admitted to the First Affiliated Hospital of He'nan University of Science and Technology from July 2020 to July 2022 were selected as the study sub-jects.The HS tissues of patients were selected as the HS group during the operation,and the normal skin tissues of HS patients were se-lected as the control group.The expression levels of PAI-1 and TLR4 mRNA in tissues were measured by fluorescence quantitative PCR(qRT-PCR);the positive expression of PAI-1 and TLR4 in tissues was determined by immunohistochemistry;Western blotting was ap-plied to determine the protein expression levels of PAI-1 and TLR4;the severity of scar tissue was evaluated using the Vancouver Scar Scale(VSS),and the epidermal barrier function of HS patients was evaluated using transcutaneous water loss(TEWL);Pearson correla-tion was applied to analyze the relationship between the expression levels of PAI-1 and TLR4 in HS tissue and the VSS and net loss of TEWL.Results PAI-1(1.54±0.32)and TLR4(1.61±0.38)mRNA expression levels in HS group were higher than those in control group(1.11±0.24)and(1.06±0.21),and the positive expression rates and protein expression level of PAI-1 and TLR4 in HS group were also obviously higher than those in control group(P<0.05);the VSS score of HS tissue was(12.01±3.48),and the TEWL value of HS tis-sue was obviously higher than that of the control group(P<0.05),the net loss of TEWL was(7.87±2.37)g·m-2·h-1;Pearson correlation analysis showed that the expression levels of PAI-1 and TLR4 in HS tissue were obviously positively correlated with the VSS and net loss of TEWL,respectively(P<0.05).Conclusion The mRNA expression levels,positive expression rates and protein expression of PAI-1 and TLR4 in HS tissue of burn patients are obviously increased,PAI-1 and TLR4 are related to the severity of HS and the dysfunction of epidermal barrier,therefore,PAI-1 and TLR4 are expected to become new targets for clinical treatment of HS.