TNAP and EHD1 are over-expressed in bovine brain capillary endothelial cells after the re-induction of blood-brain barrier properties

PLoS One. 2012;7(10):e48428. doi: 10.1371/journal.pone.0048428. Epub 2012 Oct 31.

Abstract

Although the physiological properties of the blood-brain barrier (BBB) are relatively well known, the phenotype of the component brain capillary endothelial cells (BCECs) has yet to be described in detail. Likewise, the molecular mechanisms that govern the establishment and maintenance of the BBB are largely unknown. Proteomics can be used to assess quantitative changes in protein levels and identify proteins involved in the molecular pathways responsible for cellular differentiation. Using the well-established in vitro BBB model developed in our laboratory, we performed a differential nano-LC MALDI-TOF/TOF-MS study of Triton X-100-soluble protein species from bovine BCECs displaying either limited BBB functions or BBB functions re-induced by glial cells. Due to the heterogeneity of the crude extract, we increased identification yields by applying a repeatable, reproducible fractionation process based on the proteins' relative hydrophobicity. We present proteomic and biochemical evidence to show that tissue non-specific alkaline phosphatase (TNAP) and Eps15 homology domain-containing protein 1(EDH1) are over-expressed by bovine BCECs after the re-induction of BBB properties. We discuss the impact of these findings on current knowledge of endothelial and BBB permeability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / genetics*
  • Alkaline Phosphatase / metabolism
  • Animals
  • Blood-Brain Barrier / chemistry
  • Blood-Brain Barrier / metabolism*
  • Brain / metabolism*
  • Cattle
  • Cells, Cultured
  • Endothelial Cells / chemistry
  • Endothelial Cells / metabolism*
  • Enzyme Activation / drug effects
  • Gene Expression*
  • Levamisole / pharmacology
  • Neuroglia / metabolism
  • Proteomics
  • Rats
  • Vesicular Transport Proteins / genetics*
  • Vesicular Transport Proteins / metabolism

Substances

  • EHD1 protein, human
  • Vesicular Transport Proteins
  • Levamisole
  • Alkaline Phosphatase

Grants and funding

This research was funded by the Ministère de la Recherche et de l'Enseignement Supérieur. The mass spectrometry facilities used for this study were funded by the European Regional Development Fund, the Fonds d’Industrialisation des Bassins Miniers (FIBM), the Ministère de l’Education Nationale, de l’Enseignement Supérieur et de la Recherche and the Université d’Artois. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.