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Despite comprehensive therapy and extensive research, glioblastoma (GBM) still represents the most aggressive brain tumor in adults. Glioma stem cells (GSCs) are thought to play a major role in tumor progression and resistance of GBM cells to radiochemotherapy. The PIM1 kinase has become a focus in cancer research. We have previously demonstrated that PIM1 is involved in survival of GBM cells and in GBM growth in a mouse model. However, little is known about the importance of PIM1 in cancer stem cells. Here, we report on the role of PIM1 in GBM stem cell behavior and killing. PIM1 inhibition negatively regulates the protein expression of the stem cell markers CD133 and Nestin in GBM cells (LN-18, U-87 MG). In contrast, CD44 and the astrocytic differentiation marker GFAP were up-regulated. Furthermore, PIM1 expression was increased in neurospheres as a model of GBM stem-like cells. Treatment of neurospheres with PIM1 inhibitors (TCS PIM1-1, Quercetagetin, and LY294002) diminished the cell viability associated with reduced DNA synthesis rate, increased caspase 3 activity, decreased PCNA protein expression, and reduced neurosphere formation. Our results indicate that PIM1 affects the glioblastoma stem cell behavior, and its inhibition kills glioblastoma stem-like cells, pointing to PIM1 targeting as a potential anti-glioblastoma therapy.

Eileen Moritz,1,2,* Gabriele Jedlitschky,1,* Josefine Negnal,1 Mladen V Tzvetkov,1 Günter Daum,3,4 Marcus Dörr,2,5 Stephan B Felix,2,5 Henry Völzke,2,6 Matthias Nauck,2,7 Edzard Schwedhelm,4,8 Peter Meisel,9 Thomas Kocher,9 Bernhard H Rauch,1,2,10,* Birte Holtfreter9,* 1Institute of Pharmacology, Department of General Pharmacology, University Medicine Greifswald, Greifswald, Germany; 2German Center for Cardiovascular Research (DZHK), Partner Site Greifswald, Greifswald, Germany; 3Clinic and Polyclinic for Vascular Medicine, University Heart Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; 4German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany; 5Department of Internal Medicine B, University Medicine Greifswald, Greifswald, Germany; 6Institute for Community Medicine, University Medicine Greifswald, Greifswald, Germany; 7Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany; 8Institute of Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Humburg, Germany; 9Dental Clinics, Department of Periodontology, University Medicine Greifswald, Greifswald, Germany; 10Carl von Ossietzky Universität Oldenburg, Department of Human Medicine, Section of Pharmacology and Toxicology, Oldenburg, Germany*These authors contributed equally to this workCorrespondence: Bernhard H RauchCarl von Ossietzky Universität Oldenburg, Department of Human Medicine, Section of Pharmacology and Toxicology, Carl-von-Ossietzky-Str. 9-11, Oldenburg, 26129, GermanyTel +49 (0) 441 798 4930Fax +49 (0) 441 798 3088Email Bernhard.Rauch@uni-oldenburg.dePurpose: Periodontitis is an inflammatory disease of the oral cavity with an alarmingly high prevalence within the adult population. The signaling lipid sphingosine-1-phosphate (S1P) plays a crucial role in inflammatory and immunomodulatory responses. In addition to cardiovascular disease, sepsis and tumor entities, S1P has been recently identified as both mediator and biomarker in osteoporosis. We hypothesized that S1P may play a role in periodontitis as an inflammation-prone bone destructive disorder. The goal of our study was to evaluate associations between periodontitis and S1P serum concentrations in the Study of Health in Pomerania (SHIP)-Trend cohort. In addition, we investigated the expression of S1P metabolizing enzymes in inflamed gingival tissue.Patients and Methods: We analyzed data from 3371 participants (51.6% women) of the SHIP-Trend cohort. Periodontal parameters and baseline characteristics were assessed. Serum S1P was measured by liquid chromatography tandem mass spectrometry. The expression of S1P metabolizing enzymes was determined by immunofluorescence staining of human gingival tissue.Results: S1P serum concentrations were significantly increased in subjects with both moderate and severe periodontitis, assessed as probing depth and clinical attachment loss. In contrast, no significant association of S1P was seen with caries variables (number and percentage of decayed or filled surfaces). S1P concentrations significantly increased with increasing high-sensitivity C-reactive protein (hs-CRP) levels. Interestingly, inflamed compared to normal human gingival tissue exhibited elevated expression levels of the S1P-generating enzyme sphingosine kinase 1 (SphK1).Conclusion: We report an intriguingly significant association of various periodontal parameters with serum levels of the inflammatory lipid mediator S1P. Our data point towards a key role of S1P during periodontitis pathology. Modulation of local S1P levels or its signaling properties may represent a potential future therapeutic strategy to prevent or to retard periodontitis progression and possibly reduce periodontitis-related tooth loss.Keywords: sphingosine-1-phosphate, lipid mediator, periodontitis, inflammation

Sphingosine-1-phosphate (S1P) is a versatile lipid signaling molecule and key regulator in vascular inflammation. S1P is secreted by platelets, monocytes, and vascular endothelial and smooth muscle cells. It binds specifically to a family of G-protein-coupled receptors, S1P receptors 1 to 5, resulting in downstream signaling and numerous cellular effects. S1P modulates cell proliferation and migration, and mediates proinflammatory responses and apoptosis. In the vascular barrier, S1P regulates permeability and endothelial reactions and recruitment of monocytes and may modulate atherosclerosis. Only recently has S1P emerged as a critical mediator which directly links the coagulation factor system to vascular inflammation. The multifunctional proteases thrombin and FXa regulate local S1P availability and interact with S1P signaling at multiple levels in various vascular cell types. Differential expression patterns and intracellular signaling pathways of each receptor enable S1P to exert its widespread functions. Although a vast amount of information is available about the functions of S1P and its receptors in the regulation of physiological and pathophysiological conditions, S1P-mediated mechanisms in the vasculature remain to be elucidated. This review summarizes recent findings regarding the role of S1P and its receptors in vascular wall and blood cells, which link the coagulation system to inflammatory responses in the vasculature.

The adenosine triphosphate‐binding cassette transport protein P‐glycoprotein (ABCB1) is involved in the export of beta‐amyloid from the brain into the blood, and there is evidence that age‐associated deficits in cerebral P‐glycoprotein content may be involved in Alzheimer's disease pathogenesis. P‐glycoprotein function and expression can be pharmacologically induced by a variety of compounds including extracts of Hypericum perforatum (St. John's Wort). To clarify the effect of St. John's Wort on the accumulation of beta‐amyloid and P‐glycoprotein expression in the brain, St. John's Wort extract (final hyperforin concentration 5%) was fed to 30‐day‐old male C57BL/6J‐APP/PS1 (+/−) mice over a period of 60 or 120 days, respectively. Age‐matched male C57BL/6J‐APP/PS1 (+/−) mice receiving a St. John's Wort‐free diet served as controls. Mice receiving St. John's Wort extract showed (i) significant reductions of parenchymal beta‐amyloid 1–40 and 1–42 accumulation; and (ii) moderate, but statistically significant increases in cerebrovascular P‐glycoprotein expression. Thus, the induction of cerebrovascular P‐glycoprotein may be a novel therapeutic strategy to protect the brain from beta‐amyloid accumulation, and thereby impede the progression of Alzheimer's disease.

Background: Alzheimer's disease (AD) is the most common neurodegenerative disorder leading to dementia and is characterized by the cerebral accumulation of beta-amyloid (Aβ) peptides. There is a substantial need for new therapies that modify the progression or prevent the onset of disease.[for full text, please go to the a.m. URL], 57th Annual Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN)

The placenta functions both as site for nutrition and protection of the fetus. Transport proteins, including members of the multidrug resistance protein (MRP)/ABCC subfamily, have been recognized to contribute to the latter function. MRP5 (ABCC5) was identified as transmembrane transport protein for cyclic nucleotides, especially 3',5'-cyclic GMP (cGMP), indicating an additional role in signal transduction and a potential role in placenta development. We therefore studied expression, localization, and function of MRP5 in placenta of different gestational ages. Quantitative real-time polymerase chain reaction revealed expression of MRP5 in all 60 samples from pre-term and term placenta, with a decreasing mean expression with gestational age (MRP5/18S-ratio x 1000;32 weeks: 2.91 +/- 0.73, n = 15; 32 to 37 weeks: 2.10 +/- 0.87, n = 15;37 weeks: 0.46 +/- 0.08, n = 30; P0.01). Immunofluorescence microscopy with an anti-MRP5 antibody indicated localization of MRP5 preferentially in the basal membrane of syncytiotrophoblasts and in and around fetal vessels. ATP-dependent [(3)H]cGMP transport as evidence for MRP5 function could be demonstrated in isolated basal membrane vesicles. Moreover, the influence of cellular differentiation on MRP5 expression was studied in isolated trophoblasts, revealing an increase of the MRP5 expression in parallel with the hCG production (MRP5/18S-ratio x 1000 was 2.4 +/- 0.5 at day 5 of culture and 1.45 +/- 0.5 at day 0 of culture, n = 3 preparations, significant difference with P0.05). In conclusion, MRP5 expression depends on gestational age and varies throughout the differentiation process. In view of the important role of cGMP for cellular differentiation, MRP5 may play a role in placental development in context with a specific need for cellular cGMP export.