A New Noncanonical Anionic Peptide That Translocates a Cellular Blood-Brain Barrier Model

Molecules. 2017 Oct 18;22(10):1753. doi: 10.3390/molecules22101753.

Abstract

The capacity to transport therapeutic molecules across the blood-brain barrier (BBB) represents a breakthrough in the development of tools for the treatment of many central nervous system (CNS)-associated diseases. The BBB, while being protective against infectious agents, hinders the brain uptake of many drugs. Hence, finding safe shuttles able to overcome the BBB is of utmost importance. Herein, we identify a new BBB-translocating peptide with unique properties. For years it was thought that cationic sequences were mandatory for a cell-penetrating peptide (CPP) to achieve cellular internalization. Despite being anionic at physiological pH, PepNeg (sequence (SGTQEEY) is an efficient BBB translocator that is able to carry a large cargo (27 kDa), while maintaining BBB integrity. In addition, PepNeg is able to use two distinct methods of translocation, energy-dependent and -independent, suggesting that direct penetration might occur when low concentrations of peptide are presented to cells. The discovery of this new anionic trans-BBB peptide allows the development of new delivery systems to the CNS and contributes to the need to rethink the role of electrostatic attraction in BBB-translocation.

Keywords: anionic peptide; blood–brain barrier; cell-penetrating peptide; drug-delivery systems.

MeSH terms

  • Anions / administration & dosage
  • Anions / chemistry
  • Biological Transport / genetics*
  • Blood-Brain Barrier / drug effects
  • Blood-Brain Barrier / metabolism
  • Brain / drug effects
  • Brain / pathology
  • Cell-Penetrating Peptides / chemistry
  • Cell-Penetrating Peptides / metabolism*
  • Cell-Penetrating Peptides / therapeutic use
  • Central Nervous System / drug effects
  • Central Nervous System / metabolism
  • Central Nervous System Diseases / drug therapy*
  • Central Nervous System Diseases / pathology
  • Drug Delivery Systems*
  • Humans

Substances

  • Anions
  • Cell-Penetrating Peptides