The Role Of TXNIP In Endoplasmic Reticulum Stress-related Pathways That Lead To Inflammation In Children With Myocardial Damage

Objective This study aimed to assess the expression of thioredoxin-interacting protein(TXNIP)in children with myocardial damage and to analyze the diagnostic value of this protein.It also aimed to assess that the role of TXNIP involved in endoplasmic reticulum stress-inflammation-related pathways in children with myocardial damage.Methods(1)To collect and analyze peripheral blood samples and clinical data from children with myocardial damage and healthy children.The relative mRNA expression of TXNIP in peripheral blood was detected by quantitative real-time polymerase chain reaction(qRT-PCR).To analyze the correlation between TXNIP and clinical parameters such as WBC,Plt,K~+,AST,LDH,and Carbon dioxide combining power,and to evaluate the value of its clinical application in children with myocardial damage.(2)Enzyme-linked immunosorbent assay(ELISA)was used to measure the protein level of GRP78,an endoplasmic reticulum stress marker,in the peripheral blood of children in both groups.(3)A model of inflammatory injury was constructed by using lipopolysaccharide(LPS)to stimulate H9C2 cardiomyocytes.The endoplasmic reticulum stress agonist tunicamycin(TM),the endoplasmic reticulum stress inhibitor 4-phenylbutyric acid(4-PBA),and the TXNIP siRNA were used to effect model cells.Cell viability between different groups was detected by CCK-8.The expression levels of GRP78,TXNIP and NLRP3 in each group were detected by immunofluorescence,western blot and qRT-PCR.Results(1)Comparing baseline data between children with myocardial damage and healthy children,the difference was not statistically significant(P>0.05).Statistical analysis of the clinical data showed that clinical indexes such as LDH,AST,and Carbon dioxide combining power were significantly different in children with myocardial damage compared to healthy control children(P<0.05).The expression levels of GRP78and TXNIP in the serum of children with myocardial damage were detected to be higher than those of normal children(P<0.05 or P<0.001).The expression of TXNIP did not significantly correlate with AST,LDH,and Carbon dioxide combining power(P>0.05),but was negatively correlated with the number of lymphocytes(P<0.01).When TXNIP was used as a diagnostic indicator between the two groups,the AUC was 0.7483(P<0.001),with a 95%CI of 0.6020 to 0.8945.When 1.134 was taken as its diagnostic cut-off value,its sensitivity was 95.8%and specificity was 62.5%.When TXNIP was used as a combined diagnostic index with cardiac troponin I,the results showed that the AUC was 0.9618,with a sensitivity of 79.2%and a specificity of 100%.(2)Myocardial injury model was constructed using LPS stimulation of H9C2 cells.Compared with the control group,H9C2 cell viability was significantly decreased in the LPS group,TM group,and 4-PBA+LPS group(P<0.05).Cell viability was increased in the 4-PBA+LPS group compared with the LPS group.The results showed that the expression of GRP78,TXNIP,and NLRP3 were higher after the effect of LPS or TM on H9C2 cardiomyocytes than normal controls(P<0.001).After transfection with TXNIP siRNA-3,the protein level of NLRP3 in LPS and TM-treated groups were lower than those in untransfected groups(P<0.01).Conclusion 1.The relative mRNA expression of TXNIP was increased in the serum of children with myocardial damage and may be used as a joint diagnostic index with cTnI.2.The protein level of GRP78 was increased in the serum of children with myocardial damage.3.The mechanism of myocardial damage in children caused by TXNIP may be related to the endoplasmic reticulum stress-inflammatory pathway.