M1 macrophage-derived exosomes inhibit cardiomyocyte proliferation through delivering miR-155

BMC Cardiovasc Disord. 2024 Jul 16;24(1):365. doi: 10.1186/s12872-024-03893-0.

Abstract

Background: M1 macrophages are closely associated with cardiac injury after myocardial infarction (MI). Increasing evidence shows that exosomes play a key role in pathophysiological regulation after MI, but the role of M1 macrophage-derived exosomes (M1-Exos) in myocardial regeneration remains unclear. In this study, we explored the impact of M1 macrophage-derived exosomes on cardiomyocytes regeneration in vitro and in vivo.

Methods: M0 macrophages were induced to differentiate into M1 macrophages with GM-CSF (50 ng/mL) and IFN-γ (20 ng/mL). Then M1-Exos were isolated and co-incubated with cardiomyocytes. Cardiomyocyte proliferation was detected by pH3 or ki67 staining. Quantitative real-time PCR (qPCR) was used to test the level of miR-155 in macrophages, macrophage-derived exosomes and exosome-treated cardiomyocytes. MI model was constructed and LV-miR-155 was injected around the infarct area, the proliferation of cardiomyocytes was counted by pH3 or ki67 staining. The downstream gene and pathway of miR-155 were predicted and verified by dual-luciferase reporter gene assay, qPCR and immunoblotting analysis. IL-6 (50 ng/mL) was added to cardiomyocytes transfected with miR-155 mimics, and the proliferation of cardiomyocytes was calculated by immunofluorescence. The protein expressions of IL-6R, p-JAK2 and p-STAT3 were detected by Western blot.

Results: The results showed that M1-Exos suppressed cardiomyocytes proliferation. Meanwhile, miR-155 was highly expressed in M1-Exos and transferred to cardiomyocytes. miR-155 inhibited the proliferation of cardiomyocytes and antagonized the pro-proliferation effect of interleukin 6 (IL-6). Furthermore, miR-155 targeted gene IL-6 receptor (IL-6R) and inhibited the Janus kinase 2(JAK)/Signal transducer and activator of transcription (STAT3) signaling pathway.

Conclusion: M1-Exos inhibited cardiomyocyte proliferation by delivering miR-155 and inhibiting the IL-6R/JAK/STAT3 signaling pathway. This study provided new insight and potential treatment strategy for the regulation of myocardial regeneration and cardiac repair by macrophages.

Keywords: Cardiomyocyte proliferation; Exosomes; M1 macrophage; Mir-155; Myocardial infarction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation* / drug effects
  • Cells, Cultured
  • Coculture Techniques
  • Disease Models, Animal*
  • Exosomes* / genetics
  • Exosomes* / metabolism
  • Exosomes* / transplantation
  • Interleukin-6 / metabolism
  • Janus Kinase 2* / metabolism
  • Macrophages* / metabolism
  • Male
  • Mice, Inbred C57BL
  • MicroRNAs* / genetics
  • MicroRNAs* / metabolism
  • Myocardial Infarction* / genetics
  • Myocardial Infarction* / metabolism
  • Myocardial Infarction* / pathology
  • Myocardial Infarction* / physiopathology
  • Myocytes, Cardiac* / drug effects
  • Myocytes, Cardiac* / metabolism
  • Myocytes, Cardiac* / pathology
  • Phosphorylation
  • Rats, Sprague-Dawley
  • Receptors, Interleukin-6 / genetics
  • Receptors, Interleukin-6 / metabolism
  • Regeneration
  • STAT3 Transcription Factor* / genetics
  • STAT3 Transcription Factor* / metabolism
  • Signal Transduction*

Substances

  • MicroRNAs
  • STAT3 Transcription Factor
  • Stat3 protein, rat
  • Janus Kinase 2
  • Jak2 protein, rat
  • MIRN155 microRNA, rat
  • Receptors, Interleukin-6
  • Mirn155 microRNA, mouse
  • Interleukin-6