Role and mechanism of nucleobindin 1 in inflammatory response in rats after myocardial infarction

LIU Liyuan; LI Bin; WU Xingliang; HUANG Yanxin; YI Xin

doi:10.3969/j.issn.1674-4055.2025.11.004

Abstract：Objective To investigate the role and mechanism of nucleobindin 1(NUCB1)in inflammatory response in rats after myocardial infarction(MI).Methods The blood samples were collected from 20 patients underwent coronary angiography(CAG)from Renmin Hospital of Wuhan University from Nov.2020 to July 2021.According to CAG results,the patients were divided into control group(n=10)and group of chronic total occlusion(CTO)of coronary artery(CTO group,n=10).The difference in NUCB1 level was analyzed by using proteomics,and correlation between NUCB1 and inflammatory pathway proteins was analyzed through protein-protein interaction(PPI).A MI model was established by using ligation of left anterior descending(LAD)in SD rats,and the rats were randomly divided into sham-operation group(Sham group,n=8)and MI group(MI group,n=8).After 28 d,the samples were stained with HE staining and Masson staining for reviewing morphopathology and pathological changes of MI tissue.The subcellular localization and expression of NUCB1 were observed by using immunofluorescence staining.Immunofluorescence PCR(qPCR)and Western blotting assay were used to determine the expression levels of inflammatory factors such as NUCB1,NOD-like receptor protein 3(NLRP3)and inducible cyclooxygenase(COX2)in myocardial tissue of border zone of infarction(BIZ).In addition,a hypoxia model of H9c2 cardiomyocytes was established to investigate the expression patterns of NUCB1 and inflammatory factors in the hypoxic model of cardiomyocytes.Results The serum level of NUCB1 was significantly elevated in CTO group.PPI analysis revealed that NUCB1 was correlated with inflammatory pathway proteins,including transforming growth factor-beta-induced protein(TGFBI),cathepsin B(CTSB),and complement C4A(C4A).HE staining and Masson staining showed that there was obvious inflammatory cell infiltration in the heart,loose arrangement of cardiomyocytes,and a significant increase in the area of myocardial fibrosis in MI group.The results of qPCR,immunofluorescence staining,and Western blotting assay showed that the expression level of NUCB1 was significantly increased in the myocardial tissue of BIZ,and the expression of corresponding proinflammatory proteins was also increased in MI group compared with control group(P<0.05).In the hypoxia model of H9c2 cardiomyocytes,qPCR and Western blotting assay showed that expression levels of NUCB1 and proinflammatory proteins were also increased(P<0.05).Conclusion The expression level of NUCB1 is increased in rat model of MI and hypoxic cardiomyocytes,and it may be involved in the occurrence and development of MI through inflammatory responses mediated by NLRP3 and COX2.