Are activated B cells involved in the process of myocardial fibrosis after acute myocardial infarction? An in vivo experiment.
BMC Cardiovasc Disord
; 21(1): 5, 2021 01 06.
Article
en En
| MEDLINE
| ID: mdl-33407160
ABSTRACT
BACKGROUND:
Inflammatory cells infiltrate into the ischemic and hypoxic myocardial tissue after myocardial infarction. B cells gather at the site of myocardial injury and secrete cytokines to regulate immune inflammation and fiber repair processes.METHODS:
The animal experiment used ligation of the left anterior descending (LAD) artery of C57BL/6 mice to establish a mouse acute myocardial infarction (AMI) model to observe changes in activated B cells and cytokines at different time points. Twelve-week-old C57BL/6 male mice were randomly divided into the Sham group (24 mice) (thread under the LAD artery without ligation) and the AMI group (64 mice). In addition, C57BL/6 B-cell knockout (BKO) mice and C57BL/6 wild-type (WT) mice were used to establish AMI models to observe the expression levels of cardiomyocyte cytokines, such as TNF-α IL-1ß, IL-6, TGF-ß1, COL1-A1, COL3-AIII, TIMP, and MMP9. Moreover, pathological and collagen changes in the myocardium were analysed. One-way ANOVA and LSD method was used for comparisons of multiple and pairwise groups respectively. P < 0.05 indicated significant differences.RESULTS:
An AMI model of C57BL/6 mice was established successfully. The ratio of activated B cells and the expression of TNF-α, IL-1ß, IL-6, TGF-ß1, and B cell activating factor (BAFF) in the 5-day subgroup were the highest in the myocardium, spleen and peripheral blood with the most obvious myocardial inflammatory cell infiltration. The cytokines mRNA expression levels in the 5-day subgroup of the BKO group were decreased compared with those in the WT group (P < 0.05). Among the 2-week subgroups of the Sham, WT and BKO groups, the the LVEDd and LVESd of the BKO group were lower than those of the WT group (P < 0.05), and the left ventricular ejection fraction was higher than that of the WT group (P < 0.05).CONCLUSION:
Activated B cells participate in the sustained state of myocardial inflammation and immune system activation after AMI, and may affect the metabolism of myocardial collagen after AMI by secreting cytokines. Moreover, B cells promote the expression of myocardial collagen Type I and Type III and damage the left ventricular ejection function.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Linfocitos B
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Activación de Linfocitos
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Citocinas
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Colágeno Tipo I
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Colágeno Tipo III
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Infarto del Miocardio
/
Miocardio
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Año:
2021
Tipo del documento:
Article