Catabolic effects of endothelial cell-derived microparticles on disc cells: Implications in intervertebral disc neovascularization and degeneration

Pedro H.I. Pohl, Thomas P. Lozito, Thais Cuperman, Takashi Yurube, Hong Joo Moon, Kevin Ngo, Rocky S. Tuan, Claudette St. Croix, Gwendolyn A. Sowa, Luciano M.R. Rodrigues, James D. Kang, Nam V. Vo

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Neovascularization of intervertebral discs, a phenomenon considered pathological since normal discs are primarily avascular structures, occurs most frequently in annulus fibrosus (AF) of degenerated discs. Endothelial cells (ECs) are involved in this process, but the mechanism of the interaction between AF and endothelial cells is unclear. In this study, we evaluated the effects on matrix catabolic activity of AF cells by the extracellular endothelial microparticles (EMPs) and soluble protein factors (SUP fraction) produced from ECs. Passage 1 human AF cells grown in monolayer cultures were treated for 72 h with 250 µg of EMPs or SUP fraction isolated from culture of the microvascular endothelial cell line, HEMC-I. Live-cell imaging revealed uptake of EMPs by AF cells. RT-PCR analysis demonstrated increased mRNA expression of MMP-1 (50.3-fold), MMP-3 (4.5-fold) and MMP-13 (5.5-fold) in AF cell cultures treated with EMPs compared to untreated control. Western analysis also demonstrated increased MMP protein expression in EMP-treated AF cells. AF cells treated with the SUP fraction also exhibited a dramatic increase in MMP mRNA and protein expression. Increased MMP expression is primarily due to EMP or SUP stimulation of AF cells since EMPs or SUP fraction alone contained negligible amount of MMPs. Interestingly, MMP activity was elevated in AF cell cultures treated with EMPs but not with SUP. This study revealed enhanced matrix catabolism as a molecular consequence of action of ECs on AF cells via EMPs, which might be expected during neo-angiogenesis of degenerating disc.

Original languageEnglish
Pages (from-to)1466-1474
Number of pages9
JournalJournal of Orthopaedic Research
Volume34
Issue number8
DOIs
Publication statusPublished - 2016 Aug 1

    Fingerprint

Keywords

  • endothelial cells
  • intervertebral disc degeneration
  • matrix metalloproteinases
  • microparticles
  • neo-angiogenesis

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

Pohl, P. H. I., Lozito, T. P., Cuperman, T., Yurube, T., Moon, H. J., Ngo, K., Tuan, R. S., St. Croix, C., Sowa, G. A., Rodrigues, L. M. R., Kang, J. D., & Vo, N. V. (2016). Catabolic effects of endothelial cell-derived microparticles on disc cells: Implications in intervertebral disc neovascularization and degeneration. Journal of Orthopaedic Research, 34(8), 1466-1474. https://doi.org/10.1002/jor.23298