TY - JOUR A1 - Reschke, Moritz A1 - Salvador, Ellaine A1 - Schlegel, Nicolas A1 - Burek, Malgorzata A1 - Karnati, Srikanth A1 - Wunder, Christian A1 - Förster, Carola Y. T1 - Isosteviol sodium (STVNA) reduces pro-inflammatory cytokine IL-6 and GM-CSF in an in vitro murine stroke model of the blood–brain barrier (BBB) JF - Pharmaceutics N2 - Early treatment with glucocorticoids could help reduce both cytotoxic and vasogenic edema, leading to improved clinical outcome after stroke. In our previous study, isosteviol sodium (STVNA) demonstrated neuroprotective effects in an in vitro stroke model, which utilizes oxygen-glucose deprivation (OGD). Herein, we tested the hypothesis that STVNA can activate glucocorticoid receptor (GR) transcriptional activity in brain microvascular endothelial cells (BMECs) as previously published for T cells. STVNA exhibited no effects on transcriptional activation of the glucocorticoid receptor, contrary to previous reports in Jurkat cells. However, similar to dexamethasone, STVNA inhibited inflammatory marker IL-6 as well as granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. Based on these results, STVNA proves to be beneficial as a possible prevention and treatment modality for brain ischemia-reperfusion injury-induced blood–brain barrier (BBB) dysfunction. KW - IL-6 KW - ischemia KW - isosteviol sodium (STVNA) KW - dexamethasone KW - glucocorticoid receptor KW - cerebEND Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286275 SN - 1999-4923 VL - 14 IS - 9 ER - TY - JOUR A1 - Rösing, Nils A1 - Salvador, Ellaine A1 - Güntzel, Paul A1 - Kempe, Christoph A1 - Burek, Malgorzata A1 - Holzgrabe, Ulrike A1 - Soukhoroukov, Vladimir A1 - Wunder, Christian A1 - Förster, Carola T1 - Neuroprotective Effects of Isosteviol Sodium in Murine Brain Capillary Cerebellar Endothelial Cells (cerebEND) After Hypoxia JF - Frontiers in Cellular Neuroscience N2 - Ischemic stroke is one of the leading causes of death worldwide. It damages neurons and other supporting cellular elements in the brain. However, the impairment is not only confined to the region of assault but the surrounding area as well. Besides, it also brings about damage to the blood-brain barrier (BBB) which in turn leads to microvascular failure and edema. Hence, this necessitates an on-going, continuous search for intervention strategies and effective treatment. Of late, the natural sweetener stevioside proved to exhibit neuroprotective effects and therapeutic benefits against cerebral ischemia-induced injury. Its injectable formulation, isosteviol sodium (STVNA) also demonstrated favorable results. Nonetheless, its effects on the BBB have not yet been investigated to date. As such, this present study was designed to assess the effects of STVNA in our in vitro stroke model of the BBB.The integrity and permeability of the BBB are governed and maintained by tight junction proteins (TJPs) such as claudin-5 and occludin. Our data show increased claudin-5 and occludin expression in oxygen and glucose (OGD)-deprived murine brain capillary cerebellar endothelial cells (cerebEND) after STVNa treatment. Likewise, the upregulation of the transmembrane protein integrin-αv was also observed. Finally, cell volume was reduced with the simultaneous administration of STVNA and OGD in cerebEND cells. In neuropathologies such as stroke, the failure of cell volume control is a major feature leading to loss of cells in the penumbra as well as adverse outcomes. Our initial findings, therefore, point to the neuroprotective effects of STVNA at the BBB in vitro, which warrant further investigation for a possible future clinical intervention. KW - isosteviol sodium KW - hypoxia KW - cerebEND cells KW - blood brain barrier KW - neuroprotection Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215013 SN - 1662-5102 VL - 14 ER - TY - JOUR A1 - Feldheim, Jonas A1 - Wend, David A1 - Lauer, Mara J. A1 - Monoranu, Camelia M. A1 - Glas, Martin A1 - Kleinschnitz, Christoph A1 - Ernestus, Ralf-Ingo A1 - Braunger, Barbara M. A1 - Meybohm, Patrick A1 - Hagemann, Carsten A1 - Burek, Malgorzata T1 - Protocadherin Gamma C3 (PCDHGC3) is strongly expressed in glioblastoma and its high expression is associated with longer progression-free survival of patients JF - International Journal of Molecular Sciences N2 - Protocadherins (PCDHs) belong to the cadherin superfamily and represent the largest subgroup of calcium-dependent adhesion molecules. In the genome, most PCDHs are arranged in three clusters, α, β, and γ on chromosome 5q31. PCDHs are highly expressed in the central nervous system (CNS). Several PCDHs have tumor suppressor functions, but their individual role in primary brain tumors has not yet been elucidated. Here, we examined the mRNA expression of PCDHGC3, a member of the PCDHγ cluster, in non-cancerous brain tissue and in gliomas of different World Health Organization (WHO) grades and correlated it with the clinical data of the patients. We generated a PCDHGC3 knockout U343 cell line and examined its growth rate and migration in a wound healing assay. We showed that PCDHGC3 mRNA and protein were significantly overexpressed in glioma tissue compared to a non-cancerous brain specimen. This could be confirmed in glioma cell lines. High PCDHGC3 mRNA expression correlated with longer progression-free survival (PFS) in glioma patients. PCDHGC3 knockout in U343 resulted in a slower growth rate but a significantly faster migration rate in the wound healing assay and decreased the expression of several genes involved in WNT signaling. PCDHGC3 expression should therefore be further investigated as a PFS-marker in gliomas. However, more studies are needed to elucidate the molecular mechanisms underlying the PCDHGC3 effects. KW - glioblastoma multiforme KW - glioma KW - astrocytoma KW - recurrence KW - relapse KW - mRNA KW - protein KW - brain KW - expression KW - PCDHGC3 KW - WNT signaling Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284433 SN - 1422-0067 VL - 23 IS - 15 ER - TY - JOUR A1 - Salvador, Ellaine A1 - Burek, Malgorzata A1 - Löhr, Mario A1 - Nagai, Michiaki A1 - Hagemann, Carsten A1 - Förster, Carola Y. T1 - Senescence and associated blood-brain barrier alterations in vitro JF - Histochemistry and Cell Biology N2 - Progressive deterioration of the central nervous system (CNS) is commonly associated with aging. An important component of the neurovasculature is the blood-brain barrier (BBB), majorly made up of endothelial cells joined together by intercellular junctions. The relationship between senescence and changes in the BBB has not yet been thoroughly explored. Moreover, the lack of in vitro models for the study of the mechanisms involved in those changes impede further and more in-depth investigations in the field. For this reason, we herein present an in vitro model of the senescent BBB and an initial attempt to identify senescence-associated alterations within. KW - senescence KW - in vitro model KW - aging KW - CNS diseases KW - blood–brain barrier Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267435 SN - 1432-119X VL - 156 IS - 3 ER - TY - JOUR A1 - Curtaz, Carolin J. A1 - Schmitt, Constanze A1 - Herbert, Saskia-Laureen A1 - Feldheim, Jonas A1 - Schlegel, Nicolas A1 - Gosselet, Fabien A1 - Hagemann, Carsten A1 - Roewer, Norbert A1 - Meybohm, Patrick A1 - Wöckel, Achim A1 - Burek, Malgorzata T1 - Serum-derived factors of breast cancer patients with brain metastases alter permeability of a human blood-brain barrier model JF - Fluids and Barriers of the CNS N2 - Background The most threatening metastases in breast cancer are brain metastases, which correlate with a very poor overall survival, but also a limited quality of life. A key event for the metastatic progression of breast cancer into the brain is the migration of cancer cells across the blood-brain barrier (BBB). Methods We adapted and validated the CD34\(^+\) cells-derived human in vitro BBB model (brain-like endothelial cells, BLECs) to analyse the effects of patient serum on BBB properties. We collected serum samples from healthy donors, breast cancer patients with primary cancer, and breast cancer patients with, bone, visceral or cerebral metastases. We analysed cytokine levels in these sera utilizing immunoassays and correlated them with clinical data. We used paracellular permeability measurements, immunofluorescence staining, Western blot and mRNA analysis to examine the effects of patient sera on the properties of BBB in vitro. Results The BLECs cultured together with brain pericytes in transwells developed a tight monolayer with a correct localization of claudin-5 at the tight junctions (TJ). Several BBB marker proteins such as the TJ proteins claudin-5 and occludin, the glucose transporter GLUT-1 or the efflux pumps PG-P and BCRP were upregulated in these cultures. This was accompanied by a reduced paracellular permeability for fluorescein (400 Da). We then used this model for the treatment with the patient sera. Only the sera of breast cancer patients with cerebral metastases had significantly increased levels of the cytokines fractalkine (CX3CL1) and BCA-1 (CXCL13). The increased levels of fractalkine were associated with the estrogen/progesterone receptor status of the tumour. The treatment of BLECs with these sera selectively increased the expression of CXCL13 and TJ protein occludin. In addition, the permeability of fluorescein was increased after serum treatment. Conclusion We demonstrate that the CD34\(^+\) cell-derived human in vitro BBB model can be used as a tool to study the molecular mechanisms underlying cerebrovascular pathologies. We showed that serum from patients with cerebral metastases may affect the integrity of the BBB in vitro, associated with elevated concentrations of specific cytokines such as CX3CL1 and CXCL13. KW - Metastatic breast cancer KW - Blood–brain barrier KW - In vitro models KW - CX3CL1 KW - CXCL13 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229940 VL - 17 ER - TY - JOUR A1 - Salvador, Ellaine A1 - Köppl, Theresa A1 - Hörmann, Julia A1 - Schönhärl, Sebastian A1 - Bugaeva, Polina A1 - Kessler, Almuth F. A1 - Burek, Malgorzata A1 - Ernestus, Ralf-Ingo A1 - Löhr, Mario A1 - Hagemann, Carsten T1 - Tumor Treating Fields (TTFields) induce cell junction alterations in a human 3D in vitro model of the blood-brain barrier JF - Pharmaceutics N2 - In a recent study, we showed in an in vitro murine cerebellar microvascular endothelial cell (cerebEND) model as well as in vivo in rats that Tumor-Treating Fields (TTFields) reversibly open the blood–brain barrier (BBB). This process is facilitated by delocalizing tight junction proteins such as claudin-5 from the membrane to the cytoplasm. In investigating the possibility that the same effects could be observed in human-derived cells, a 3D co-culture model of the BBB was established consisting of primary microvascular brain endothelial cells (HBMVEC) and immortalized pericytes, both of human origin. The TTFields at a frequency of 100 kHz administered for 72 h increased the permeability of our human-derived BBB model. The integrity of the BBB had already recovered 48 h post-TTFields, which is earlier than that observed in cerebEND. The data presented herein validate the previously observed effects of TTFields in murine models. Moreover, due to the fact that human cell-based in vitro models more closely resemble patient-derived entities, our findings are highly relevant for pre-clinical studies. KW - blood-brain barrier KW - Tumor-Treating Fields (TTFields) KW - CNS disorders KW - human brain microvascular endothelial cells (HBMVEC) KW - human cells KW - 3D in vitro model Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304830 SN - 1999-4923 VL - 15 IS - 1 ER - TY - JOUR A1 - Salvador, Ellaine A1 - Kessler, Almuth F. A1 - Domröse, Dominik A1 - Hörmann, Julia A1 - Schaeffer, Clara A1 - Giniunaite, Aiste A1 - Burek, Malgorzata A1 - Tempel-Brami, Catherine A1 - Voloshin, Tali A1 - Volodin, Alexandra A1 - Zeidan, Adel A1 - Giladi, Moshe A1 - Ernestus, Ralf-Ingo A1 - Löhr, Mario A1 - Förster, Carola Y. A1 - Hagemann, Carsten T1 - Tumor Treating Fields (TTFields) reversibly permeabilize the blood–brain barrier in vitro and in vivo JF - Biomolecules N2 - Despite the availability of numerous therapeutic substances that could potentially target CNS disorders, an inability of these agents to cross the restrictive blood–brain barrier (BBB) limits their clinical utility. Novel strategies to overcome the BBB are therefore needed to improve drug delivery. We report, for the first time, how Tumor Treating Fields (TTFields), approved for glioblastoma (GBM), affect the BBB’s integrity and permeability. Here, we treated murine microvascular cerebellar endothelial cells (cerebEND) with 100–300 kHz TTFields for up to 72 h and analyzed the expression of barrier proteins by immunofluorescence staining and Western blot. In vivo, compounds normally unable to cross the BBB were traced in healthy rat brain following TTFields administration at 100 kHz. The effects were analyzed via MRI and immunohistochemical staining of tight-junction proteins. Furthermore, GBM tumor-bearing rats were treated with paclitaxel (PTX), a chemotherapeutic normally restricted by the BBB combined with TTFields at 100 kHz. The tumor volume was reduced with TTFields plus PTX, relative to either treatment alone. In vitro, we demonstrate that TTFields transiently disrupted BBB function at 100 kHz through a Rho kinase-mediated tight junction claudin-5 phosphorylation pathway. Altogether, if translated into clinical use, TTFields could represent a novel CNS drug delivery strategy. KW - blood–brain barrier KW - TTFields KW - CNS disorders Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288057 SN - 2218-273X VL - 12 IS - 10 ER -