scholarly journals Netrin-1 plays a role in the effect of 10 weeks moderate exercise on myocardial fibrosis in rats

2018 ◽  
Author(s):  
Zhou Daliang ◽  
Fu Hong ◽  
Yu Lifang ◽  
Zhang Lingling ◽  
Wei Lin ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Aerobic Exercise ◽  
Sham Group ◽  
Volume Fraction ◽  
Necrosis Factor Alpha ◽  
Deleted In Colorectal Cancer ◽  
Collagen Volume Fraction ◽  
Tnf Α ◽  
Factor Alpha

AbstractThis study aimed to determine the effect of Netrin-1 and its receptor on acute myocardial infarction in rats after aerobic exercise.METHODS:Twenty-four rats were randomly divided into three groups: the sham group (n = 8); acute myocardial infarction model group (AMI)(n = 8); and aerobic exercise treatment after acute myocardial infarction group(ET) (n = 8). After 10 weeks, the levels of netrin-1, tumor necrosis factor alpha α(TNF-α), and interleukin 6(IL-6) in the serum were measured. The expression of matrix metalloproteinases 2 and 9(MMP2,9), and their inhibitor, tissue inhibitor of metalloproteinases 2(TIMP2), myocardial netrin-1, Deleted in colorectal cancer(DCC) receptor were evaluated. Histopathological were evaluated. The collagen volume fraction of myocardial tissues was also calculated.RESULTS:Compared to the sham group, the AMI group and ET groups showed increased levels of serum TNF-α, IL-6 and significantly reduced levels of netrin-1. Levels of TNF-α and IL-6 were significantly reduced in the ET group compared to the AMI group, whereas the level of netrin-1 was increased. The expression of myocardial MMP2,9 was significantly increased in the AMI group compared to the sham group, whereas that of myocardial netrin-1, inhibitor of TIMP2 and DCC receptor, was significantly reduced. Compared to AMI group, the ET group showed reduced expression of myocardial MMP2,9 proteins, whereas expression of myocardial netrin-1, inhibitor of TIMP2 and DCC receptor, was significantly increased. The collagen volume fraction of myocardial tissues was significantly increased in the AMI group and ET group compared to the sham group, with the greater increase being noted in the AMI group.CONCLUSIONS: Aerobic exercise could increase levels of serum netrin-1 myocardial netrin-1, and DCC receptor and reduced expression of myocardial MMP2,9 proteins, to improve the degree of fibrosis following myocardial infarction in rats.

scholarly journals Are activated B cells involved in the process of myocardial fibrosis after acute myocardial infarction? -An in vivo experiment

2020 ◽  
Author(s):  
Fanrui Mo ◽  
Ying Luo ◽  
Yuluan Yan ◽  
Juan Li ◽  
Shayi Lai ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
B Cells ◽  
Sham Group ◽  
Inflammatory Cells ◽  
Expression Levels ◽  
Tnf Α ◽  
Myocardial Collagen ◽  
Tgf Β1 ◽  
Activated B Cells

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 intended to use ligation of the left anterior descending branch of C57BL/6 mice to establish a mice AMI model to observe the changes of activated B cells and cytokines at different time points. 88 12-week-old C57BL/6 male mice were divided into the Sham group (24 mice) and acute myocardial infarction (AMI ) group (64 mice) randomly. Besides, C57BL/6 Bmi-1 knock out (BKO) mice and C57BL/6 wild-type (WT) mice were used to establish AMI models to observe the expression levels of cardiomyocyte factors including TNF-α and IL-1β, IL-6, TGF-β1, COL1-A1, COL3-A1, TIMP-1, and MMP9. Moreover, pathological and collagen changes in the myocardium were analyzed. One-way ANOVA analysis of variance was used for comparison between multiple groups, and the LSD method was used for pairwise comparison between groups. P < 0.05 indicated statistical differences.Results: AMI model of C57BL/6 mice was established successfully. The ratio of activated B cells and expression of TNF-α, IL-1β, IL-6, TGF-β1, and BAFF in 5 days subgroup was highest in the myocardium, spleen, and peripheral blood with the most obvious myocardial inflammatory cells infiltration. mRNA expression levels of TNF-α, IL-1β, IL-6, TGF-β1 in 5 days subgroup of the BKO group were decreased compared with the WT group (P < 0.05). Among 2 weeks subgroups of Sham, WT, and BKO groups, the LVEDd and LVESd in the BKO and WT groups were less than those in the Sham group (P < 0.05). The LVEDd and LVESd of the BKO group were less than the WT group,EF was higher than the WT group (P < 0.05).Conclusion: Activated B cells participated in the sustained state of myocardial inflammation and immune system activation after AMI via promoting the secretion of cytokines, and may affect the metabolism of myocardial collagen. Moreover, B cells could damage the heart structure and left ventricular ejection function by promoting the expression of myocardial collagen Type I and type III.

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