Downregulation of microRNA-21 contributes to decreased collagen expression in venous malformations via transforming growth factor-β/Smad3/microRNA-21 signaling feedback loop

J Vasc Surg Venous Lymphat Disord. 2022 Mar;10(2):469-481.e2. doi: 10.1016/j.jvsv.2021.08.020. Epub 2021 Sep 22.

Abstract

Objective: Venous malformations (VMs) are the most frequent vascular malformations and are characterized by dilated and tortuous veins with a dysregulated vascular extracellular matrix. The purpose of the present study was to investigate the potential involvement of microRNA-21 (miR-21), a multifunctional microRNA tightly associated with extracellular matrix regulation, in the pathogenesis of VMs.

Methods: The expression of miR-21, collagen I, III, and IV, transforming growth factor-β (TGF-β), and Smad3 (mothers against decapentaplegic homolog 3) was evaluated in VMs and normal skin tissue using in situ hybridization, immunohistochemistry, Masson trichrome staining, and real-time polymerase chain reaction. Human umbilical vein endothelial cells (HUVECs) were used to explore the underlying mechanisms.

Results: miR-21 expression was markedly decreased in the VM specimens compared with normal skin, in parallel with downregulation of collagen I, III, and IV and the TGF-β/Smad3 pathway in VMs. Moreover, our data demonstrated that miR-21 positively regulated the expression of collagens in HUVECs and showed a positive association with the TGF-β/Smad3 pathway in the VM tissues. In addition, miR-21 was found to mediate TGF-β-induced upregulation of collagens in HUVECs. Our data have indicated that miR-21 and the TGF-β/Smad3 pathway could form a positive feedback loop to synergistically regulate endothelial collagen synthesis. In addition, TGF-β/Smad3/miR-21 feedback loop signaling was upregulated in bleomycin-treated HUVECs and VM specimens, which was accompanied by increased collagen deposition.

Conclusions: To the best of our knowledge, the present study has, for the first time, revealed downregulation of miR-21 in VMs, which might contribute to decreased collagen expression via the TGF-β/Smad3/miR-21 signaling feedback loop. These findings provide new information on the pathogenesis of VMs and might facilitate the development of new therapies for VMs.

Keywords: Collagen; Feedback loop; TGF-β; Venous malformations; miR-21.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bleomycin / toxicity
  • Case-Control Studies
  • Cells, Cultured
  • Collagen / genetics
  • Collagen / metabolism*
  • Down-Regulation
  • Feedback, Physiological
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Human Umbilical Vein Endothelial Cells / metabolism*
  • Human Umbilical Vein Endothelial Cells / pathology
  • Humans
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Phosphorylation
  • Signal Transduction
  • Skin / blood supply*
  • Smad3 Protein / metabolism*
  • Transforming Growth Factor beta / metabolism*
  • Vascular Malformations / genetics
  • Vascular Malformations / metabolism*
  • Vascular Malformations / pathology
  • Veins / abnormalities
  • Veins / metabolism*
  • Veins / pathology

Substances

  • MIRN21 microRNA, human
  • MicroRNAs
  • SMAD3 protein, human
  • Smad3 Protein
  • Transforming Growth Factor beta
  • Bleomycin
  • Collagen