Reversible opening of the blood-brain barrier by claudin-5-binding variants of Clostridium perfringens enterotoxin's claudin-binding domain. (April 2018)

• Record Type: Journal Article
• Authors: Neuhaus, Winfried; Piontek, Anna; Protze, Jonas; Eichner, Miriam; Mahringer, Anne; Subileau, Eva-Anne; Lee, In-Fah M.; Schulzke, Jörg D.; Krause, Gerd; Piontek, Jörg
• Is Part Of: Biomaterials. Volume 161(2018)
• Page Start: 129
• Page End: 143
• Publication Date: 2018-04
• Subjects: Blood brain barrier -- Clostridium perfringens enterotoxin -- Claudin -- Tight junction -- Paracellular drug delivery; Biomedical materials -- Periodicals; Biocompatible Materials -- Periodicals; Biomatériaux -- Périodiques; 610.28
• DOI: 10.1016/j.biomaterials.2018.01.028
• Languages: English
• ISSNs: 0142-9612

Abstract

Abstract: The blood-brain barrier (BBB) prevents entry of neurotoxic substances but also that of drugs into the brain. Here, the paracellular barrier is formed by tight junctions (TJs) with claudin-5 (Cldn5) being the main sealing constituent. Transient BBB opening by targeting Cldn5 could improve paracellular drug delivery. The non-toxic C-terminal domain of Clostridium perfringens enterotoxin (cCPE) binds to a subset of claudins, e.g., Cldn3, -4. Structure-based mutagenesis was used to generate Cldn5-binding variants (cCPE-Y306W/S313H and cCPE-N218Q/Y306W/S313H). These cCPE-variants were tested for transient TJ opening using multiple in vitro BBB models: Primary porcine brain endothelial cells, coculture of primary rat brain endothelial cells with astrocytes and mouse cerebEND cells. cCPE-Y306W/S313H and cCPE-N218Q/Y306W/S313H but neither cCPE-wt nor cCPE-Y306A/L315A (not binding to claudins) decreased transendothelial electrical resistance in a concentration-dependent and reversible manner. Furthermore, permeability of carboxyfluorescein (with size of CNS drugs) was increased. cCPE-Y306W/S313H but neither cCPE-wt nor cCPE-Y306A/L315A bound to Cldn5-expressing brain endothelial cells. However, freeze-fracture EM showed that cCPE-Y306W/S313H did not cause drastic TJ breakdown. In sum, Cldn5-binding cCPE-variants enabled mild and transient opening of brain endothelial TJs. Using reliable in vitro BBB models, the results demonstrate that cCPE-based biologics designed to bind Cldn5 improve paracellular drug delivery across the BBB. Highlights: Clostridium perfringens enterotoxin-based claudin-5 modulators were generated. They improve blood brain barrier permeability in size-selective and reversible manner. They provide novel biologicals for drug delivery across blood brain barrier.