Abstract 13957: TNF-α/MiR-133a Involved in Myocardial Leukocytes Infiltration and Cardiac Dysfunction on the Early Phase of Coronary Microembolization
Objectives: MicroRNAs are small non-coding RNAs that regulate gene expression at the post-transcriptional level by either degradation or translational repression of a target mRNA. It has been demonstrated that miR-133a plays a critical role on inflammatory response after acute myocardial infarction. However, it is unknown about myocardial expression of miR-133a after coronary microembolization (CME) in mini-pigs.
Methods: Ten mini-pigs were enroll in this study, including sham-operation group (n=5), CME group (n=7) and adalimumab pre-treatment group (n=6) (TNF-α antibody, 2mg/kg intracoronary injection before CME). Magnetic resonance imaging (3.0-T) was performed at baseline, 6th hour and one week after procedure. Serum TNF-α and troponin T were also detected. Myocardial expressions of miR-133a were detected by realtime-PCR method. Myocardium specimens were embedded in paraffin for hematoxylin and eosin (HE) staining, while number of leukocytes infiltration were analyzed by Leica DFC 320 digital soft.
Results: Compared with sham-operation group, serum level of troponin T and TNF-α were increased significantly in CME group, while leukocyte infiltration on microembolization associated myocardium was also increased. Interestingly, myocardial expression of miR-133a was increased significantly after CME (2.33±0.62 vs. 1.28±0.68, P<0.05). Cardiac function detected by MRI was decreased in CME group (LVEF at 6th hour: 55.2% vs. 61.4%, P<0.05; LVEF at one week: 56.4% vs. 62.8%, P<0.05). We found that pre-treatment with adalimumab not only significantly improved LVEF after CME (6th hour: 59.3% vs. 55.2%, P<0.05; one week: 60.2% vs. 56.4%, P<0.05), but also decreased myocardial expression of miR-133a (1.36±0.58 vs. 2.33±0.62, P<0.05), which had a positive relation with the average number of leukocytes infiltration on microembolization area (r=0.364, P<0.05) .
Conclusions: TNF-α/miR-133a expression might be involved in cardiac dysfunction after CME, which was associated with the process of leukocytes infiltration.
Author Disclosures: Z. Chen: None. Y. Cao: None. J. Qian: None. J. Ma: None. Y. Zou: None. J. Ge: None.
- © 2015 by American Heart Association, Inc.