TY  - JOUR
A1  - Novakova, Iveta
A1  - Subileau, Eva-Anne
A1  - Toegel, Stefan
A1  - Gruber, Daniela
A1  - Lachmann, Bodo
A1  - Urban, Ernst
A1  - Chesne, Christophe
A1  - Noe, Christian R.
A1  - Neuhaus, Winfried
T1  - Transport Rankings of Non-Steroidal Antiinflammatory Drugs across Blood-Brain Barrier In Vitro Models
JF  - PLoS ONE
N2  - The aim of this work was to conduct a comprehensive study about the transport properties of NSAIDs across the blood-brain barrier (BBB) in vitro. Transport studies with celecoxib, diclofenac, ibuprofen, meloxicam, piroxicam and tenoxicam were accomplished across Transwell models based on cell line PBMEC/C1-2, ECV304 or primary rat brain endothelial cells. Single as well as group substance studies were carried out. In group studies substance group compositions, transport medium and serum content were varied, transport inhibitors verapamil and probenecid were added. Resulted permeability coefficients were compared and normalized to internal standards diazepam and carboxyfluorescein. Transport rankings of NSAIDs across each model were obtained. Single substance studies showed similar rankings as corresponding group studies across PBMEC/C1-2 or ECV304 cell layers. Serum content, glioma conditioned medium and inhibitors probenecid and verapamil influenced resulted permeability significantly. Basic differences of transport properties of the investigated NSAIDs were similar comparing all three in vitro BBB models. Different substance combinations in the group studies and addition of probenecid and verapamil suggested that transporter proteins are involved in the transport of every tested NSAID. Results especially underlined the importance of same experimental conditions (transport medium, serum content, species origin, cell line) for proper data comparison.
KW  - NSAIDs
KW  - astrocytes
KW  - transport inhibition assay
KW  - drug-drug interactions
KW  - diazepam
KW  - permeability
KW  - glioma
KW  - scanning electron microscopy
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119992
VL  - 9
IS  - 1
ER  - 
TY  - JOUR
A1  - Djuzenova, Cholpon S.
A1  - Memmel, Simon
A1  - Sukhorukov, Vladimir L.
A1  - Höring, Marcus
A1  - Westerling, Katherine
A1  - Fiedler, Vanessa
A1  - Katzer, Astrid
A1  - Krohne, Georg
A1  - Flentje, Michael
T1  - Cell Surface Area and  Membrane Folding in Glioblastoma Cell Lines Differing in PTEN and p53 Status
N2  - Glioblastoma multiforme (GBM) is characterized by rapid growth, invasion and resistance to chemo−/radiotherapy. The complex cell surface morphology with abundant membrane folds, microvilli, filopodia and other membrane extensions is believed to contribute to the highly invasive behavior and therapy resistance of GBM cells. The present study addresses the mechanisms leading to the excessive cell membrane area in five GBM lines differing in mutational status for PTEN and p53. In addition to scanning electron microscopy (SEM), the membrane area and folding were quantified by dielectric measurements of membrane capacitance using the single-cell electrorotation (ROT) technique. The osmotic stability and volume regulation of GBM cells were analyzed by video microscopy. The expression of PTEN, p53, mTOR and several other marker proteins involved in cell growth and membrane synthesis were examined by Western blotting. The combined SEM, ROT and osmotic data provided independent lines of evidence for a large variability in membrane area and folding among tested GBM lines. Thus, DK-MG cells (wild type p53 and wild type PTEN) exhibited the lowest degree of membrane folding, probed by the area-specific capacitance Cm = 1.9 µF/cm2. In contrast, cell lines carrying mutations in both p53 and PTEN (U373-MG and SNB19) showed the highest Cm values of 3.7–4.0 µF/cm2, which corroborate well with their heavily villated cell surface revealed by SEM. Since PTEN and p53 are well-known inhibitors of mTOR, the increased membrane area/folding in mutant GBM lines may be related to the enhanced protein and lipid synthesis due to a deregulation of the mTOR-dependent downstream signaling pathway. Given that membrane folds and extensions are implicated in tumor cell motility and metastasis, the dielectric approach presented here provides a rapid and simple tool for screening the biophysical cell properties in studies on targeting chemo- or radiotherapeutically the migration and invasion of GBM and other tumor types.
KW  - cell membranes
KW  - hypotonic
KW  - capacitance
KW  - isotonic
KW  - microvilli
KW  - membrane characteristics
KW  - membrane proteins
KW  - scanning electron microscopy
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111322
ER  -