Cathepsin proteases promote angiogenic sprouting and laser-induced choroidal neovascularisation in mice.

Abstract

Cysteine cathepsins are a family of proteases involved in intracellular protein turnover and extracellular matrix degradation. Cathepsin B (Ctsb) and cathepsin Z (Ctsz) promote tumorigenesis and Ctsb is a known modulator of tumor angiogenesis. We therefore investigated the angiomodulatory function of these cathepsins in vitro as well as in a mouse model of laser-induced choroidal neovascularization (laser-CNV). Ctsb(-/-), Ctsz(-/-), Ctsb/Ctsz double-knockout (Ctsb/z DKO), and wild type (WT) mice underwent argon laser treatment to induce choroidal neovascularization (CNV). The neovascularized area was quantified individually for each lesion at 14 days after laser coagulation. In vitro the effects of cathepsin inhibitors on angiogenesis were analysed by endothelial cell (EC) spheroid sprouting and EC invadosome assays. Retinas from cathepsin KO mice did not show gross morphological abnormalities. In the laser CNV model, however, Ctsb/z DKO mice displayed a significantly reduced neovascularized area compared to WT (0.027 mm(2) vs. 0.052 mm(2); p = 0.012), while single knockouts did not differ significantly from WT. In line, VEGF-induced EC spheroid sprouting and invadosome formation were not significantly altered by a specific cathepsin B inhibitor alone, but significantly suppressed when more than one cathepsin was inhibited. Our results demonstrate that laser-CNV formation is significantly reduced in Ctsb/z DKO mice. In line, EC sprouting and invadosome formation are blunted when more than one cathepsin is inhibited in vitro. These results reveal an angiomodulatory potential of cathepsins with partial functional redundancies between different cathepsin family members.

• Authors: A Bühler, S Berger, F Bengsch, G Martin, H Han, S Vierkotten, A Pielen, D Boehringer, G Schlunck, S Fauser, H T Agostini, T Reinheckel, A Stahl
• Journal: Experimental eye research (Exp Eye Res) Vol. 115 Pg. 73-8 (Oct 2013) ISSN: 1096-0007 [Electronic] England
• PMID: 23800510 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemical References

• Enzyme Inhibitors
• Matrix Metalloproteinase Inhibitors
• VEGFA protein, human
• Vascular Endothelial Growth Factor A
• Cathepsin Z
• Cathepsin B

Topics

• Animals
• Cathepsin B (antagonists & inhibitors, physiology)
• Cathepsin Z (antagonists & inhibitors, physiology)
• Choroid (blood supply)
• Choroidal Neovascularization (enzymology, pathology)
• Disease Models, Animal
• Enzyme Inhibitors (pharmacology)
• Extracellular Matrix (metabolism)
• Human Umbilical Vein Endothelial Cells (drug effects)
• Laser Coagulation
• Lasers, Gas
• Matrix Metalloproteinase Inhibitors (pharmacology)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Spheroids, Cellular
• Vascular Endothelial Growth Factor A (pharmacology)