A 3D biomimetic model of lymphatics reveals cell-cell junction tightening and lymphedema via a cytokine-induced ROCK2/JAM-A complex

Proc Natl Acad Sci U S A. 2023 Oct 10;120(41):e2308941120. doi: 10.1073/pnas.2308941120. Epub 2023 Oct 2.

Abstract

Impaired lymphatic drainage and lymphedema are major morbidities whose mechanisms have remained obscure. To study lymphatic drainage and its impairment, we engineered a microfluidic culture model of lymphatic vessels draining interstitial fluid. This lymphatic drainage-on-chip revealed that inflammatory cytokines that are known to disrupt blood vessel junctions instead tightened lymphatic cell-cell junctions and impeded lymphatic drainage. This opposing response was further demonstrated when inhibition of rho-associated protein kinase (ROCK) was found to normalize fluid drainage under cytokine challenge by simultaneously loosening lymphatic junctions and tightening blood vessel junctions. Studies also revealed a previously undescribed shift in ROCK isoforms in lymphatic endothelial cells, wherein a ROCK2/junctional adhesion molecule-A (JAM-A) complex emerges that is responsible for the cytokine-induced lymphatic junction zippering. To validate these in vitro findings, we further demonstrated in a genetic mouse model that lymphatic-specific knockout of ROCK2 reversed lymphedema in vivo. These studies provide a unique platform to generate interstitial fluid pressure and measure the drainage of interstitial fluid into lymphatics and reveal a previously unappreciated ROCK2-mediated mechanism in regulating lymphatic drainage.

Keywords: ROCK2; cell–cell adhesion; lymphatic drainage; lymphatics-on-chip; lymphedema.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Biomimetics
  • Cytokines / metabolism
  • Endothelial Cells / metabolism
  • Intercellular Junctions
  • Junctional Adhesion Molecule A* / metabolism
  • Lymphatic Vessels* / metabolism
  • Lymphedema* / genetics
  • Lymphedema* / metabolism
  • Mice
  • rho-Associated Kinases* / metabolism

Substances

  • Cytokines
  • Junctional Adhesion Molecule A
  • Rock2 protein, mouse
  • rho-Associated Kinases