Effect of miR-۴۱۲-۵p–loaded exosomes in H۹c۲ cardiomyocytes via the MAPK pathway

Objective(s): MicroRNAs (miRNAs) are small non-coding RNAs that function in all biological processes. Recent findings suggest that exosomes, which are small vesicles abundantly secreted by various cell types, can transport miRNAs to target cells. Here, we elucidated the effect of miRNA-loaded exosomes on lipopolysaccharide (LPS)-induced inflammation in H۹c۲ cardiomyocytes.Materials and Methods: Exosomes were isolated from mesenchymal stem cells (MSC) and loaded with miR-۴۱۲-۵p. Additionally, the effect of the miR-۴۱۲-۵p-loaded exosomes on LPS-induced inflammation in H۹c۲ cardiomyocytes was evaluated by assessing the levels of nitric oxide (NO), reactive oxygen species (ROS), and prostaglandin E۲ (PGE۲). The expression of cyclooxygenase-۲ (COX-۲), inducible nitric oxide synthase (iNOS), inflammatory cytokines, and mitogen-activated protein kinase (MAPK) signaling factors was evaluated using reverse transcription-quantitative PCR and western blotting.Results: miR-۴۱۲-۵p-loaded exosomes inhibited LPS-induced secretion of inflammatory mediators (NO, PGE۲, and ROS), pro-inflammatory cytokines (IL-۱β and IL-۶), and COX-۲ and iNOS expression. Additionally, miR-۴۱۲-۵p-loaded exosomes significantly decreased the expression of MAPK signaling molecules, including p-extracellular signal-regulated kinase (ERK), p-p۳۸, and p-Jun kinase (JNK), in H۹c۲ cardiomyocytes.Conclusion: These findings showed that miR-۴۱۲-۵p-loaded exosomes ameliorated LPS-induced inflammation in H۹c۲ cardiomyocytes by inhibiting COX-۲ and iNOS expression, inflammatory mediators, and pro-inflammatory cytokines via the MAPK pathway. The findings indicate that miR-۴۱۲-۵p-loaded exosomes may be effective for the prevention of myocardial injury.

Keywords:

Cardiomyocytes , Exosome , Inflammation , MAPK pathway , MiRNA-۴۱۲-۵p