TY  - JOUR
A1  - Gomes, Sara F. Martins
A1  - Westermann, Alexander J.
A1  - Sauerwein, Till
A1  - Hertlein, Tobias
A1  - Förstner, Konrad U.
A1  - Ohlsen, Knut
A1  - Metzger, Marco
A1  - Shusta, Eric V.
A1  - Kim, Brandon J.
A1  - Appelt-Menzel, Antje
A1  - Schubert-Unkmeir, Alexandra
T1  - Induced pluripotent stem cell-derived brain endothelial cells as a cellular model to study Neisseria meningitidis infection
JF  - Frontiers in Microbiology
N2  - Meningococcal meningitis is a severe central nervous system infection that occurs when Neisseria meningitidis (Nm) penetrates brain endothelial cells (BECs) of the meningeal blood-cerebrospinal fluid barrier. As a human-specific pathogen, in vivo models are greatly limited and pose a significant challenge. In vitro cell models have been developed, however, most lack critical BEC phenotypes limiting their usefulness. Human BECs generated from induced pluripotent stem cells (iPSCs) retain BEC properties and offer the prospect of modeling the human-specific Nm interaction with BECs. Here, we exploit iPSC-BECs as a novel cellular model to study Nm host-pathogen interactions, and provide an overview of host responses to Nm infection. Using iPSC-BECs, we first confirmed that multiple Nm strains and mutants follow similar phenotypes to previously described models. The recruitment of the recently published pilus adhesin receptor CD147 underneath meningococcal microcolonies could be verified in iPSC-BECs. Nm was also observed to significantly increase the expression of pro-inflammatory and neutrophil-specific chemokines IL6, CXCL1, CXCL2, CXCL8, and CCL20, and the secretion of IFN-γ and RANTES. For the first time, we directly observe that Nm disrupts the three tight junction proteins ZO-1, Occludin, and Claudin-5, which become frayed and/or discontinuous in BECs upon Nm challenge. In accordance with tight junction loss, a sharp loss in trans-endothelial electrical resistance, and an increase in sodium fluorescein permeability and in bacterial transmigration, was observed. Finally, we established RNA-Seq of sorted, infected iPSC-BECs, providing expression data of Nm-responsive host genes. Altogether, this model provides novel insights into Nm pathogenesis, including an impact of Nm on barrier properties and tight junction complexes, and suggests that the paracellular route may contribute to Nm traversal of BECs.
KW  - Neisseria meningitidis
KW  - meningococcus
KW  - bacteria
KW  - stem cells
KW  - blood-cerebrospinal fluid barrier
KW  - blood-brain barrier
KW  - brain endothelial cells
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201562
VL  - 10
IS  - 1181
ER  - 
TY  - JOUR
A1  - Schuhmann, Michael K.
A1  - Stoll, Guido
A1  - Papp, Lena
A1  - Bohr, Arne
A1  - Volkmann, Jens
A1  - Fluri, Felix
T1  - Electrical stimulation of the mesencephalic locomotor region has no impact on blood–brain barrier alterations after cerebral photothrombosis in rats
JF  - International Journal of Molecular Science
N2  - Blood–brain barrier (BBB) disruption is a critical event after ischemic stroke, which results in edema formation and hemorrhagic transformation of infarcted tissue. BBB dysfunction following stroke is partly mediated by proinflammatory agents. We recently have shown that high frequency stimulation of the mesencephalic locomotor region (MLR-HFS) exerts an antiapoptotic and anti-inflammatory effect in the border zone of cerebral photothrombotic stroke in rats. Whether MLR-HFS also has an impact on BBB dysfunction in the early stage of stroke is unknown. In this study, rats were subjected to photothrombotic stroke of the sensorimotor cortex and implantation of a stimulating microelectrode into the ipsilesional MLR. Thereafter, either HFS or sham stimulation of the MLR was applied for 24 h. After scarifying the rats, BBB disruption was assessed by determining albumin extravasation and tight junction integrity (claudin 3, claudin 5, and occludin) using Western blot analyses and immunohistochemistry. In addition, by applying zymography, expression of pro-metalloproteinase-9 (pro-MMP-9) was analyzed. No differences were found regarding infarct size and BBB dysfunction between stimulated and unstimulated animals 24 h after induction of stroke. Our results indicate that MLR-HFS neither improves nor worsens the damaged BBB after stroke. Attenuating cytokines/chemokines in the perilesional area, as mediated by MLR-HFS, tend to play a less significant role in preventing the BBB integrity.
KW  - photothrombotic stroke
KW  - deep brain stimulation
KW  - mesencephalic locomotor region
KW  - blood-brain barrier
KW  - tight junctions
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201284
SN  - 1422-0067
VL  - 20
IS  - 16
ER  -