Monocyte chemotactic protein-1 regulates voltage-gated K+ channels and macrophage transmigration

J Neuroimmune Pharmacol. 2009 Mar;4(1):47-59. doi: 10.1007/s11481-008-9135-1. Epub 2008 Nov 26.

Abstract

Progressive human immunodeficiency virus (HIV)-1 infection and virus-induced neuroinflammatory responses effectuate monocyte-macrophage transmigration across the blood-brain barrier (BBB). A key factor in mediating these events is monocyte chemotactic protein-1 (MCP-1). Upregulated glial-derived MCP-1 in HIV-1-infected brain tissues generates a gradient for monocyte recruitment into the nervous system. We posit that the inter-relationships between MCP-1, voltage-gated ion channels, cell shape and volume, and cell mobility underlie monocyte transmigration across the BBB. In this regard, MCP-1 serves both as a chemoattractant and an inducer of monocyte-macrophage ion flux affecting cell shape and mobility. To address this hypothesis, MCP-1-treated bone marrow-derived macrophages (BMM) were analyzed for gene and protein expression, electrophysiology, and capacity to migrate across a laboratory constructed BBB. MCP-1 enhanced K+ channel gene (KCNA3) and channel protein expression. Electrophysiological studies revealed that MCP-1 increased outward K+ currents in a dose-dependent manner. In vitro studies demonstrated that MCP-1 increased BMM migration across an artificial BBB, and the MCP-1-induced BMM migration was blocked by tetraethylammonium, a voltage-gated K+ channel blocker. Together these data demonstrated that MCP-1 affects macrophage migratory movement through regulation of voltage-gated K+ channels and, as such, provides a novel therapeutic strategy for neuroAIDS.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Animals
  • Blood-Brain Barrier / cytology
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / physiology*
  • Cell Movement / physiology*
  • Cell Separation
  • Cells, Cultured
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / physiology*
  • Chemokines / physiology
  • Chemotaxis, Leukocyte / drug effects
  • Humans
  • Immunohistochemistry
  • In Vitro Techniques
  • Macrophages / physiology*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, SCID
  • Patch-Clamp Techniques
  • Potassium Channels, Voltage-Gated / agonists
  • Potassium Channels, Voltage-Gated / physiology*
  • RNA / biosynthesis
  • RNA / isolation & purification
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tomography, Emission-Computed, Single-Photon

Substances

  • Actins
  • CCL2 protein, human
  • Chemokine CCL2
  • Chemokines
  • Potassium Channels, Voltage-Gated
  • RNA