title: Bacillus anthracis protease InhA increases blood-brain barrier permeability and contributes to cerebral hemorrhages.
abstract: Hemorrhagic meningitis is a fatal complication of anthrax, but its pathogenesis remains poorly understood. The present study examined the role of B. anthracis-secreted metalloprotease InhA on monolayer integrity and permeability of human brain microvasculature endothelial cells (HBMECs) which constitute the blood-brain barrier (BBB). Treatment of HBMECs with purified InhA resulted in a time-dependent decrease in trans-endothelial electrical resistance (TEER) accompanied by zonula occluden-1 (ZO-1) degradation. An InhA-expressing B. subtilis exhibited increased permeability of HBMECs, which did not occur with the isogenic inhA deletion mutant (ΔinhA) of B. anthracis, compared with the corresponding wild-type strain. Mice intravenously administered with purified InhA or nanoparticles-conjugated to InhA demonstrated a time-dependent Evans Blue dye extravasation, leptomeningeal thickening, leukocyte infiltration, and brain parenchymal distribution of InhA indicating BBB leakage and cerebral hemorrhage. Mice challenged with vegetative bacteria of the ΔinhA strain of B. anthracis exhibited a significant decrease in leptomeningeal thickening compared to the wildtype strain. Cumulatively, these findings indicate that InhA contributes to BBB disruption associated with anthrax meningitis through proteolytic attack on the endothelial tight junctional protein zonula occluden (ZO)-1.
authors: National Center for Biodefense and Infectious Diseases, Department of Molecular and Microbiology, George Mason University, Manassas, Virginia, United States of America.
authors: Dhritiman V
authors: DV
authors: Mukherjee
authors: Jessica H
authors: JH
authors: Tonry
authors: Kwang Sik
authors: KS
authors: Kim
authors: Nalini
authors: N
authors: Ramarao
authors: Taissia G
authors: TG
authors: Popova
authors: Charles
authors: C
authors: Bailey
authors: Serguei
authors: S
authors: Popov
authors: Myung-Chul
authors: MC
authors: Chung
mesh_terms: D000818:Animals; D000881:Anthrax / Q000382:microbiology / Q000473:pathology; D001408:Bacillus anthracis / Q000201:enzymology*; D001426:Bacterial Proteins / Q000378:metabolism*; D001812:Blood-Brain Barrier / Q000382:microbiology* / Q000473:pathology*; D015153:Blotting, Western; D002543:Cerebral Hemorrhage / Q000382:microbiology* / Q000473:pathology*; D003593:Cytoplasm / Q000378:metabolism; D017097:Electric Impedance; D042783:Endothelial Cells / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D005260:Female; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D045726:Metalloproteases / Q000378:metabolism*; D051379:Mice; D050505:Mutant Proteins / Q000378:metabolism; D054118:Nanospheres; D010539:Permeability; D010750:Phosphoproteins / Q000378:metabolism; D062826:Zonula Occludens-1 Protein
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D050505:Mutant Proteins; D010750:Phosphoproteins; C569042:TJP1 protein, human; C569043:Tjp1 protein, mouse; D062826:Zonula Occludens-1 Protein; D045726:Metalloproteases