Switching from astrocytic neuroprotection to neurodegeneration by cytokine stimulation

Abstract

were involved in this neurodegeneration. The neurotoxicity-mediating effect of IMA was faithfully reproduced by human astrocytes. Moreover, glia-dependent toxicity was also observed, when IMA cultures were stimulated with CM, and the culture medium was transferred to neurons. Such neurotoxicity was prevented when astrocytes were treated by p38 kinase inhibitors or dexamethasone, whereas such compounds had no effect when added to neurons. Conversely, treatment of neurons with five different drugs, including resveratrol and CEP1347, prevented toxicity of astrocyte supernatants. Thus, the sequential IMA-LUHMES neuroinflammation model is suitable for separate profiling of both glial-directed and directly neuroprotective strategies. Moreover, direct evaluation in co-cultures of the same cells allows for testing of therapeutic effectiveness in more complex settings, in which astrocytes affect pharmacological properties of neurons.Keywords LUHMES · Astrocyte · p38 kinase · Neuroinflammation · Neuropharmacology Abstract Astrocytes, the largest cell population in the human brain, are powerful inflammatory effectors. Several studies have examined the interaction of activated astrocytes with neurons, but little is known yet about human neurotoxicity under such situations and about strategies of neuronal rescue. To address this question, immortalized murine astrocytes (IMA) were combined with human LUHMES neurons and stimulated with an inflammatory (TNF, IL-1) cytokine mix (CM). Neurotoxicity was studied both in co-cultures and in monocultures after transfer of conditioned medium from activated IMA. Interventions with >20 drugs were used to profile the model system. Control IMA supported neurons and protected them from neurotoxicants. Inflammatory activation reduced this protection, and prolonged exposure of co-cultures to CM triggered neurotoxicity. Neither the added cytokines nor the release of NO from astrocytes Liudmila Efremova and Petra Chovancova have contributed equally to this study.

Canagliflozin mediated dual inhibition of mitochondrial glutamate dehydrogenase and complex I: an off-target adverse effect

“…Liquid phase was collected and evaporated using a vacuum concentrator followed by solubilization in 150 µl 2% 5-sulfosalicylic acid. AAs were quantified using a Sykam S433 AA analyzer (Sykam, Fürstenfeldbruck, Germany) 53 . Briefly, AAs were separated by high-performance liquid chromatography and subsequent post-column derivatization with ninhydrin.…”

In vitro acute and developmental neurotoxicity screening: an overview of cellular platforms and high-throughput technical possibilities

“…For such studies, the availability of a pure, defined, and well-characterized astrocyte population is highly desirable (Kuegler et al 2010(Kuegler et al , 2012Schildknecht et al 2012;Kleiderman et al 2015). Murine microglia and astrocytes have been extensively characterized for inflammation studies and neuronal co-cultures (Falsig et al 2004a(Falsig et al , b, 2006(Falsig et al , 2008Lund et al 2006;Efremova et al 2015Efremova et al , 2016. Some studies on the human counterparts are available, but the characterization is still lagging considerably behind (Pei et al 2015;Palm et al 2015).…”

Time and space-resolved quantification of plasma membrane sialylation for measurements of cell function and neurotoxicity

“…Here, we studied the metabolic incorporation of an azidetagged sugar precursor (Ac 4 ManNAz) as Az-Sia into the glycocalyx of mature human neurons (LUHMES). These cells (Scholz et al 2011) are a frequently used model for human neurotoxicity (Delp et al 2018b(Delp et al , 2019Efremova et al 2017;Ganjam et al 2019;Harris et al 2018;Krug et al 2013;Singh et al 2018;Skirzewski et al 2018;Stiegler et al 2011;Tong et al 2018). We asked the question on whether the sialylation capacity can be used as an early functional readout of neurotoxicity.…”