Evaluation of inflammatory miRNA155 and 146a expression in heart tissue of ovalbumin-sensitized male rats

Asthma is a chronic pulmonary inflammation occurred in response to different allergens, leading to respiratory system insufficiency. The production of different inflammatory factors and enhanced immune system response may affect the function of other organs. The aim of this study was to investigate the expression of inflammatory microRNAs in cardiac tissue in asthmatic rat model.

In this study, the animals were allocated into Control and Asthmatic rats (n=8). To induce asthma, rats were challenged with ovalbumin. 14 days after induction of asthma, rats were euthanized and Hematoxylin-Eosin staining was performed to assess pathological changes in pulmonary tissue. Serum levels of cardiac enzymes were measured using ELISA kits. Finally, transcription level of inflammatory miRNAs, miRNA-146a and -155, were measured using real-time PCR analysis.

Based on our findings, histological examination indicated the existence of pathological changes in pulmonary tissue after asthma induction. Bright-field analysis revealed an existence of inflammatory response and cytotoxicity in cardiac tissue. Also, the serum levels of CpK-MB, ALT, and AST were significantly higher in the serum of asthmatic group compared to control group (p<0.05). Finally, asthmatic condition induced the expression of (2-fold) miRNA-146a and (1.5-fold)-155 in cardiac tissue, respectively.

As a conclusion, it could be concluded that asthmatic condition induces systemic inflammation in cardiac tissue. On a more general note, we propose that therapeutical approaches directed to inflammatory pathway may be required to preserve cardiac injuries caused of asthma.