TGF-beta and TNF-alpha cooperatively induce mesenchymal transition of lymphatic endothelial cells via activation of Activin signals

PLoS One. 2020 May 1;15(5):e0232356. doi: 10.1371/journal.pone.0232356. eCollection 2020.

Abstract

Lymphatic systems play important roles in the maintenance of fluid homeostasis and undergo anatomical and physiological changes during inflammation and aging. While lymphatic endothelial cells (LECs) undergo mesenchymal transition in response to transforming growth factor-β (TGF-β), the molecular mechanisms underlying endothelial-to-mesenchymal transition (EndMT) of LECs remain largely unknown. In this study, we examined the effect of TGF-β2 and tumor necrosis factor-α (TNF-α), an inflammatory cytokine, on EndMT using human skin-derived lymphatic endothelial cells (HDLECs). TGF-β2-treated HDLECs showed increased expression of SM22α, a mesenchymal cell marker accompanied by increased cell motility and vascular permeability, suggesting HDLECs to undergo EndMT. Our data also revealed that TNF-α could enhance TGF-β2-induced EndMT of HDLECs. Furthermore, both cytokines induced the production of Activin A while decreasing the expression of its inhibitory molecule Follistatin, and thus enhancing EndMT. Finally, we demonstrated that human dermal lymphatic vessels underwent EndMT during aging, characterized by double immunostaining for LYVE1 and SM22α. These results suggest that both TGF-β and TNF-α signals play a central role in EndMT of LECs and could be potential targets for senile edema.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activins / metabolism*
  • Endothelial Cells / metabolism
  • Endothelial Cells / physiology*
  • Epithelial-Mesenchymal Transition / physiology*
  • HEK293 Cells
  • Humans
  • Lymphatic Vessels / cytology
  • Receptors, Transforming Growth Factor beta / physiology*
  • Signal Transduction*
  • Smad2 Protein / physiology
  • Trans-Activators / physiology
  • Tumor Necrosis Factor-alpha / physiology*
  • rho-Associated Kinases / metabolism

Substances

  • MRTFA protein, human
  • Receptors, Transforming Growth Factor beta
  • SMAD2 protein, human
  • Smad2 Protein
  • TNF protein, human
  • Trans-Activators
  • Tumor Necrosis Factor-alpha
  • Activins
  • rho-Associated Kinases

Grant support

This work was supported in part by a grant for the Precursory Research for Embryonic Science and Technology (PRESTO: JPMJPR12M3) (to TW) from the Japan Science and Technology Agency; Grants-in-Aid for Scientific Research on Innovative Areas, Cellular, and Molecular Basis for Neuro-vascular Wiring (23122504) (to TW) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (MEXT); Grant-in-Aid for Young Scientists (B) (15K21394 to YY) and Scientific Research (C) (17K07157 to YY) from the Japan Society for the Promotion of Science (JSPS); grants from Uehara Memorial Foundation (to TW); the Japan Foundation for Applied Enzymology (to YY); and Project for Promoting Leading-edge Research in Oral Science at Tokyo Medical and Dental University (TMDU) (to YY and TW). This study was also conducted as part of a research program of the Project for Cancer Research and Therapeutic Evolution (P-CREATE), the Japan Agency for Medical Research and Development (AMED) (JP18cm0106239 to YTM; 17cm0106613h0001 to TW). The funder provided support in the form of salaries for authors KT, SN and KK, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.