Glucocorticoid-induced cell-derived matrix modulates transforming growth factor β2 signaling in human trabecular meshwork cells

Sci Rep. 2020 Sep 24;10(1):15641. doi: 10.1038/s41598-020-72779-w.

Abstract

Aberrant remodeling of trabecular meshwork (TM) extracellular matrix (ECM) may induce ocular hypertensive phenotypes in human TM (hTM) cells to cause ocular hypertension, via a yet unknown mechanism. Here, we show that, in the absence of exogenous transforming growth factor-beta2 (TGFβ2), compared with control matrices (VehMs), glucocorticoid-induced cell-derived matrices (GIMs) trigger non-Smad TGFβ2 signaling in hTM cells, correlated with overexpression/activity of structural ECM genes (fibronectin, collagen IV, collagen VI, myocilin), matricellular genes (connective tissue growth factor [CTGF], secreted protein, acidic and rich in cysteine), crosslinking genes/enzymes (lysyl oxidase, lysyl oxidase-like 2-4, tissue transglutaminase-2), and ECM turnover genes/enzymes (matrix metalloproteinases-MMP2,14 and their inhibitors-TIMP2). However, in the presence of exogenous TGFβ2, VehMs and GIMs activate Smad and non-Smad TGFβ2 signaling in hTM cells, associated with overexpression of α-smooth muscle actin (α-SMA), and differential upregulation of aforementioned ECM genes/proteins with new ones emerging (collagen-I, thrombospondin-I, plasminogen activator inhibitor, MMP1, 9, ADAMTS4, TIMP1); with GIM-TGFβ2-induced changes being mostly more pronounced. This suggests dual glaucomatous insults potentiate profibrotic signaling/phenotypes. Lastly, we demonstrate type I TGFβ receptor kinase inhibition abrogates VehM-/GIM- and/or TGFβ2-induced upregulation of α-SMA and CTGF. Collectively, pathological TM microenvironments are sufficient to elicit adverse cellular responses that may be ameliorated by targeting TGFβ2 pathway.

Publication types

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

MeSH terms

  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism
  • Glucocorticoids / pharmacology*
  • Humans
  • Matrix Metalloproteinase 2 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Protein Glutamine gamma Glutamyltransferase 2
  • Protein-Lysine 6-Oxidase / metabolism
  • Signal Transduction / drug effects*
  • Trabecular Meshwork / cytology*
  • Trabecular Meshwork / drug effects*
  • Transforming Growth Factor beta2 / metabolism*
  • Transforming Growth Factor beta2 / pharmacology

Substances

  • Glucocorticoids
  • TGM2 protein, human
  • Transforming Growth Factor beta2
  • LOX protein, human
  • Protein-Lysine 6-Oxidase
  • Protein Glutamine gamma Glutamyltransferase 2
  • Matrix Metalloproteinase 2
  • Matrix Metalloproteinase 9