Distinct Contributions of Astrocytes and Pericytes to Neuroinflammation Identified in a 3D Human Blood-Brain Barrier on a Chip

PLoS One. 2016 Mar 1;11(3):e0150360. doi: 10.1371/journal.pone.0150360. eCollection 2016.

Abstract

Neurovascular inflammation is a major contributor to many neurological disorders, but modeling these processes in vitro has proven to be difficult. Here, we microengineered a three-dimensional (3D) model of the human blood-brain barrier (BBB) within a microfluidic chip by creating a cylindrical collagen gel containing a central hollow lumen inside a microchannel, culturing primary human brain microvascular endothelial cells on the gel's inner surface, and flowing medium through the lumen. Studies were carried out with the engineered microvessel containing endothelium in the presence or absence of either primary human brain pericytes beneath the endothelium or primary human brain astrocytes within the surrounding collagen gel to explore the ability of this simplified model to identify distinct contributions of these supporting cells to the neuroinflammatory response. This human 3D BBB-on-a-chip exhibited barrier permeability similar to that observed in other in vitro BBB models created with non-human cells, and when stimulated with the inflammatory trigger, tumor necrosis factor-alpha (TNF-α), different secretion profiles for granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) were observed depending on the presence of astrocytes or pericytes. Importantly, the levels of these responses detected in the 3D BBB chip were significantly greater than when the same cells were co-cultured in static Transwell plates. Thus, as G-CSF and IL-6 have been reported to play important roles in neuroprotection and neuroactivation in vivo, this 3D BBB chip potentially offers a new method to study human neurovascular function and inflammation in vitro, and to identify physiological contributions of individual cell types.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Astrocytes / cytology
  • Astrocytes / metabolism*
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / metabolism*
  • Brain / blood supply
  • Brain / cytology
  • Brain / metabolism*
  • Capillary Permeability / drug effects
  • Cell Culture Techniques / methods
  • Cells, Cultured
  • Coculture Techniques
  • Collagen / metabolism
  • Granulocyte Colony-Stimulating Factor / metabolism
  • Humans
  • Interleukin-6 / metabolism
  • Microfluidic Analytical Techniques / methods*
  • Microscopy, Confocal
  • Pericytes / cytology
  • Pericytes / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • Interleukin-6
  • Tumor Necrosis Factor-alpha
  • Granulocyte Colony-Stimulating Factor
  • Collagen

Grants and funding

This work was supported by the Defense Advanced Research Projects Agency under Cooperative Agreement Number W911NF-12-2-0036 and the Wyss Institute for Biologically Inspired Engineering at Harvard University. The content of the information does not necessarily reflect the position or the policy of the Defense Advanced Research Projects Agency or the U.S. Government and no official endorsement should be inferred. Additional funding was provided by Sverige-Amerika Stiftelsen [http://sweamfo.se], Carl Trygger Stiftelse [http://www.carltryggersstiftelse.se], Erik och Edith Fernstrom’s stiftelse [https://internwebben.ki.se/en/erik-and-edith-fernstrom-foundation-medical-research] (AH) and KTH opportunities fund [https://www.kth.se/en/opportunities] (EAF). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.