Adrenergic Agonists Activate Transcriptional Activity in Immortalized Neuronal Cells From the Mouse Suprachiasmatic Nucleus

The suprachiasmatic nucleus of the hypothalamus (SCN) houses the central circadian oscillator of mammals. The main neurotransmitters produced in the SCN are γ-amino-butyric acid, arginine-vasopressin (AVP), vasoactive intestinal peptide (VIP), pituitary-derived adenylate cyclase-activating peptide (PACAP), prokineticin 2, neuromedin S, and gastrin-releasing peptide (GRP). Apart from these, catecholamines and their receptors were detected in the SCN as well. In this study, we confirmed the presence of β-adrenergic receptors in SCN and a mouse SCN-derived immortalized cell line by immunohistochemical, immuno-cytochemical, and pharmacological techniques. We then characterized the effects of β-adrenergic agonists and antagonists on cAMP-regulated element (CRE) signaling. Moreover, we investigated the interaction of β-adrenergic signaling with substances influencing parallel signaling pathways. Our findings have potential implications on the role of stress (elevated adrenaline) on the biological clock and may explain some of the side effects of β-blockers applied as anti-hypertensive drugs.

Analyzing the Impact of the Highest Expressed Epstein-Barr Virus-Encoded microRNAs on the Host Cell Transcriptome

The Epstein-Barr virus (EBV) has a very high prevalence (>90% in adults), establishes a lifelong latency after primary infection, and exerts an oncogenic potential. This dsDNA virus encodes for various molecules, including microRNAs (miRs), which can be detected in the latent and lytic phases with different expression levels and affect, among others, immune evasion and malignant transformation. In this study, the different EBV miRs are quantified in EBV-positive lymphomas, and the impact on the host cell transcriptome of the most abundant EBV miRs will be analyzed using comparative RNA sequencing analyses. The EBV miRs ebv-miR-BART1, -BART4, -BART17, and -BHRF1-1 were most highly expressed, and their selective overexpression in EBV-negative human cells resulted in a large number of statistically significantly down- and up-regulated host cell genes. Functional analyses showed that these dysregulated target genes are involved in important cellular processes, including growth factor pathways such as WNT, EGF, FGF, and PDGF, as well as cellular processes such as apoptosis regulation and inflammation. Individual differences were observed between these four analyzed EBV miRs. In particular, ebv-miR-BHRF1-1 appears to be more important for malignant transformation and immune evasion than the other EBV miRs.

A toolbox to analyze collective cell migration, proliferation and cellular organization simultaneously

BACKGROUND

Analyses of collective cell migration and orientation phenomena are needed to assess the behavior of multicellular clusters. While some tools to the authors' knowledge none is capable to analyze collective migration, cellular orientation and proliferation in phase contrast images simultaneously.

METHODS

We provide a tool based to analyze phase contrast images of dense cell layers. PIV is used to calculatevelocity fields, while the structure tensor provides cellular orientation. An artificial neural network is used to identify cell division events, allowing to correlate migratory and organizational phenomena with cell density.

CONCLUSION

The presented tool allows the simultaneous analysis of collective cell behavior from phase contrast images in terms of migration, (self-)organization and proliferation.

Elucidation of GPR55-Associated Signaling behind THC and LPI Reducing Effects on Ki67-Immunoreactive Nuclei in Patient-Derived Glioblastoma Cells

GPR55 is involved in many physiological and pathological processes. In cancer, GPR55 has been described to show accelerating and decelerating effects in tumor progression resulting from distinct intracellular signaling pathways. GPR55 becomes activated by LPI and various plant-derived, endogenous, and synthetic cannabinoids. Cannabinoids such as THC exerted antitumor effects by inhibiting tumor cell proliferation or inducing apoptosis. Besides its effects through CB1 and CB2 receptors, THC modulates cellular responses among others via GPR55. Previously, we reported a reduction in Ki67-immunoreactive nuclei of human glioblastoma cells after GPR55 activation in general by THC and in particular by LPI. In the present study, we investigated intracellular mechanisms leading to an altered number of Ki67+ nuclei after stimulation of GPR55 by LPI and THC. Pharmacological analyses revealed a strongly involved PLC-IP3 signaling and cell-type-specific differences in Gα-, Gβγ-, RhoA-ROCK, and calcineurin signaling. Furthermore, immunochemical visualization of the calcineurin-dependent transcription factor NFAT revealed an unchanged subcellular localization after THC or LPI treatment. The data underline the cell-type-specific diversity of GPR55-associated signaling pathways in coupling to intracellular G proteins. Furthermore, this diversity might determine the outcome and the individual responsiveness of tumor cells to GPR55 stimulation by cannabin oids.

Time- and Concentration-Dependent Adverse Effects of Paclitaxel on Non-Neuronal Cells in Rat Primary Dorsal Root Ganglia

Paclitaxel is a chemotherapeutic agent used to treat a wide range of malignant tumors. Although it has anti-tumoral properties, paclitaxel also shows significant adverse effects on the peripheral nervous system, causing peripheral neuropathy. Paclitaxel has previously been shown to exert direct neurotoxic effects on primary DRG neurons. However, little is known about paclitaxel's effects on non-neuronal DRG cells. They provide mechanical and metabolic support and influence neuronal signaling. In the present study, paclitaxel effects on primary DRG non-neuronal cells were analyzed and their concentration or/and time dependence investigated. DRGs of Wister rats (6-8 weeks old) were isolated, and non-neuronal cell populations were separated by the density gradient centrifugation method. Different concentrations of Paclitaxel (0.01 µM-10 µM) were tested on cell viability by MTT assay, cell death by lactate dehydrogenase (LDH) assay, and propidium iodide (PI) assay, as well as cell proliferation by Bromodeoxyuridine (BrdU) assay at 24 h, 48 h, and 72 h post-treatment. Furthermore, phenotypic effects have been investigated by using immunofluorescence techniques. Paclitaxel exhibited several toxicological effects on non-neuronal cells, including a reduction in cell viability, an increase in cell death, and an inhibition of cell proliferation. These effects were concentration- and time-dependent. Cellular and nuclear changes such as shrinkage, swelling of cell bodies, nuclear condensation, chromatin fragmentation, retraction, and a loss in processes were observed. Paclitaxel showed adverse effects on primary DRG non-neuronal cells, which might have adverse functional consequences on sensory neurons of the DRG, asking for consideration in the management of peripheral neuropathy.

MACC1-induced migration in tumors: Current state and perspective

Malignant tumors are still a global, heavy health burden. Many tumor types cannot be treated curatively, underlining the need for new treatment targets. In recent years, metastasis associated in colon cancer 1 (MACC1) was identified as a promising biomarker and drug target, as it is promoting tumor migration, initiation, proliferation, and others in a multitude of solid cancers. Here, we will summarize the current knowledge about MACC1-induced tumor cell migration with a special focus on the cytoskeletal and adhesive systems. In addition, a brief overview of several in vitro models used for the analysis of cell migration is given. In this context, we will point to issues with the currently most prevalent models used to study MACC1-dependent migration. Lastly, open questions about MACC1-dependent effects on tumor cell migration will be addressed.

Jamming Transitions in Astrocytes and Glioblastoma Are Induced by Cell Density and Tension

Collective behavior of cells emerges from coordination of cell-cell-interactions and is important to wound healing, embryonic and tumor development. Depending on cell density and cell-cell interactions, a transition from a migratory, fluid-like unjammed state to a more static and solid-like jammed state or vice versa can occur. Here, we analyze collective migration dynamics of astrocytes and glioblastoma cells using live cell imaging. Furthermore, atomic force microscopy, traction force microscopy and spheroid generation assays were used to study cell adhesion, traction and mechanics. Perturbations of traction and adhesion were induced via ROCK or myosin II inhibition. Whereas astrocytes resided within a non-migratory, jammed state, glioblastoma were migratory and unjammed. Furthermore, we demonstrated that a switch from an unjammed to a jammed state was induced upon alteration of the equilibrium between cell-cell-adhesion and tension from adhesion to tension dominated, via inhibition of ROCK or myosin II. Such behavior has implications for understanding the infiltration of the brain by glioblastoma cells and may help to identify new strategies to develop anti-migratory drugs and strategies for glioblastoma-treatment.

Glioblastoma-Derived Three-Dimensional Ex Vivo Models to Evaluate Effects and Efficacy of Tumor Treating Fields (TTFields)

Glioblastoma (GBM) displays a wide range of inter- and intra-tumoral heterogeneity contributing to therapeutic resistance and relapse. Although Tumor Treating Fields (TTFields) are effective for the treatment of GBM, there is a lack of ex vivo models to evaluate effects on patients' tumor biology or to screen patients for treatment efficacy. Thus, we adapted patient-derived three-dimensional tissue culture models to be compatible with TTFields application to tissue culture. Patient-derived primary cells (PDPC) were seeded onto murine organotypic hippocampal slice cultures (OHSC), and microtumor development with and without TTFields at 200 kHz was observed. In addition, organoids were generated from acute material cultured on OHSC and treated with TTFields. Lastly, the effect of TTFields on expression of the Ki67 proliferation marker was evaluated on cultured GBM slices. Microtumors exhibited increased sensitivity towards TTFields compared to monolayer cell cultures. TTFields affected tumor growth and viability, as the size of microtumors and the percentage of Ki67-positive cells decreased after treatment. Nevertheless, variability in the extent of the response was preserved between different patient samples. Therefore, these pre-clinical GBM models could provide snapshots of the tumor to simulate patient treatment response and to investigate molecular mechanisms of response and resistance.

Surgical Anatomy of the Radial Nerve at the Dorsal Region of the Humerus: A Cadaveric Study

BACKGROUND

Surgery for humeral shaft fractures is associated with a high risk of iatrogenic radial nerve palsy (RNP). Plausible causes are difficult anatomical conditions and variants.

METHODS

We performed a cadaveric study with 23 specimens (13 female and 10 male Caucasian donors) to assess the course and anatomy of the radial nerve (RN) with its branches alongside the humeral shaft. The accuracy of identification of the RN in the surgical field was analyzed by measuring the location, course, diameter, and form of each nerve and vessel of interest.

RESULTS

The RN is not a single structure running alongside the humeral shaft; at least 4 parallel structures crossed the dorsal humerus in all subjects. The RN was accompanied by 2 vessels and at least 1 other nerve, which we named the musculocutaneous branch (MCB). With an oval profile and an average diameter of 3.1 mm (range, 2.6 to 3.8 mm), the MCB was thinner but, in some cases, close to the average diameter of 4.7 mm (range, 4.0 to 5.2 mm) of the RN, which had a round profile. Both accompanying vessels had similar diameters: 3.5 mm (range, 2.6 to 4.2 mm) for the radial collateral artery and 4.0 mm (range, 2.9 to 4.4 mm) for the medial collateral artery. In 20 (87%) of the cases, the RN ran proximal to and in 3 (13%) of the cases, distal to the MCB. Furthermore, a distal safe zone of at least 110 mm (range, 110 to 160 mm) was found, measured from the radial (lateral) epicondyle proximally.

CONCLUSIONS

The RN does not cross the dorsal humerus alone, as often stated in anatomical textbooks, but runs parallel to vessels and at least 1 nerve branch with a similar appearance. Thus, for reliable preservation of the RN, we recommend identification and protection of all crossing structures in posterior humeral surgeries 110 mm proximal to the radial epicondyle.

MACC1-Induced Collective Migration Is Promoted by Proliferation Rather Than Single Cell Biomechanics

Metastasis-associated in colon cancer 1 (MACC1) is a marker for metastasis, tumor cell migration, and increased proliferation in colorectal cancer (CRC). Tumors with high MACC1 expression show a worse prognosis and higher invasion into neighboring structures. Yet, many facets of the pro-migratory effects are not fully understood. Atomic force microscopy and single cell live imaging were used to quantify biomechanical and migratory properties in low- and high-MACC1-expressing CRC cells. Furthermore, collective migration and expansion of small, cohesive cell colonies were analyzed using live cell imaging and particle image velocimetry. Lastly, the impact of proliferation on collective migration was determined by inhibition of proliferation using mitomycin. MACC1 did not affect elasticity, cortex tension, and single cell migration of CRC cells but promoted collective migration and colony expansion in vitro. Measurements of the local velocities in the dense cell layers revealed proliferation events as regions of high local speeds. Inhibition of proliferation via mitomycin abrogated the MACC1-associated effects on the collective migration speeds. A simple simulation revealed that the expansion of cell clusters without proliferation appeared to be determined mostly by single cell properties. MACC1 overexpression does not influence single cell biomechanics and migration but only collective migration in a proliferation-dependent manner. Thus, targeting proliferation in high-MACC1-expressing tumors may offer additional effects on cell migration.

Microglia-Dependent and Independent Brain Cytoprotective Effects of Mycophenolate Mofetil During Neuronal Damage

Acute lesions of the central nervous system often lead to permanent limiting deficits. In addition to the initial primary damage, accompanying neuroinflammation is responsible for progression of damage. Mycophenolate mofetil (MMF) as a selective inhibitor of inosine 5-monophosphate dehydrogenase (IMPDH) was shown to modulate the inflammatory response and promote neuronal survival when applied in specific time windows after neuronal injury. The application of brain cytoprotective therapeutics early after neuronal damage is a fundamental requirement for a successful immunomodulation approach. This study was designed to evaluate whether MMF can still mediate brain cytoprotection when applied in predefined short time intervals following CNS injury. Furthermore, the role of microglia and changes in IMPDH2 protein expression were assessed. Organotypic hippocampal slice cultures (OHSC) were used as an in vitro model and excitotoxically lesioned with N-methyl-aspartate (NMDA). Clodronate (Clo) was used to deplete microglia and analyze MMF mediated microglia independent effects. The temporal expression of IMPDH2 was studied in primary glial cell cultures treated with lipopolysaccharide (LPS). In excitotoxically lesioned OHSC a significant brain cytoprotective effect was observed between 8 and 36 h but not within 8 and 24 h after the NMDA damage. MMF mediated effects were mainly microglia dependent at 24, 36, 48 h after injury. However, further targets like astrocytes seem to be involved in protective effects 72 h post-injury. IMPDH2 expression was detected in primary microglia and astrocyte cell cultures. Our data indicate that MMF treatment in OHSC should still be started no later than 8–12 h after injury and should continue at least until 36 h post-injury. Microglia seem to be an essential mediator of the observed brain cytoprotective effects. However, a microglia-independent effect was also found, indicating involvement of astrocytes.

Nimodipine Exerts Time-Dependent Neuroprotective Effect after Excitotoxical Damage in Organotypic Slice Cultures

During injuries in the central nervous system, intrinsic protective processes become activated. However, cellular reactions, especially those of glia cells, are frequently unsatisfactory, and further exogenous protective mechanisms are necessary. Nimodipine, a lipophilic L-type calcium channel blocking agent is clinically used in the treatment of aneurysmal subarachnoid haemorrhage with neuroprotective effects in different models. Direct effects of nimodipine on neurons amongst others were observed in the hippocampus as well as its influence on both microglia and astrocytes. Earlier studies proposed that nimodipine protective actions occur not only via calcium channel-mediated vasodilatation but also via further time-dependent mechanisms. In this study, the effect of nimodipine application was investigated in different time frames on neuronal damage in excitotoxically lesioned organotypic hippocampal slice cultures. Nimodipine, but not nifedipine if pre-incubated for 4 h or co-applied with NMDA, was protective, indicating time dependency. Since blood vessels play no significant role in our model, intrinsic brain cell-dependent mechanisms seems to strongly be involved. We also examined the effect of nimodipine and nifedipine on microglia survival. Nimodipine seem to be a promising agent to reduce secondary damage and reduce excitotoxic damage.

Assessment of Neuronal Damage in Brain Slice Cultures Using Machine Learning Based on Spatial Features

Neuronal damage presents a major health issue necessitating extensive research to identify mechanisms of neuronal cell death and potential therapeutic targets. Commonly used models are slice cultures out of different brain regions extracted from mice or rats, excitotoxically, ischemic, or traumatically lesioned and subsequently treated with potential neuroprotective agents. Thereby cell death is regularly assessed by measuring the propidium iodide (PI) uptake or counting of PI-positive nuclei. The applied methods have a limited applicability, either in terms of objectivity and time consumption or regarding its applicability. Consequently, new tools for analysis are needed. Here, we present a framework to mimic manual counting using machine learning algorithms as tools for semantic segmentation of PI-positive dead cells in hippocampal slice cultures. Therefore, we trained a support vector machine (SVM) to classify images into either “high” or “low” neuronal damage and used naïve Bayes, discriminant analysis, random forest, and a multilayer perceptron (MLP) as classifiers for segmentation of dead cells. In our final models, pixel-wise accuracies of up to 0.97 were achieved using the MLP classifier. Furthermore, a SVM-based post-processing step was introduced to differentiate between false-positive and false-negative detections using morphological features. As only very few false-positive objects and thus training data remained when using the final model, this approach only mildly improved the results. A final object splitting step using Hough transformations was used to account for overlap, leading to a recall of up to 97.6% of the manually assigned PI-positive dead cells. Taken together, we present an analysis tool that can help to objectively and reproducibly analyze neuronal damage in brain-derived slice cultures, taking advantage of the morphology of pycnotic cells for segmentation, object splitting, and identification of false positives.

Variants of Oxidized Regenerated Cellulose and Their Distinct Effects on Neuronal Tissue

Based on oxidized regenerated cellulose (ORC), several hemostyptic materials, such as Tabotamp^®, Equicel^® and Equitamp^®, have been developed to approach challenging hemostasis in neurosurgery. The present study compares ORC that differ in terms of compositions and properties, regarding their structure, solubility, pH values and effects on neuronal tissue. Cytotoxicity was detected via DNA-binding fluorescence dye in Schwann cells, astrocytes, and neuronal cells. Additionally, organotypic hippocampal slice cultures (OHSC) were analyzed, using propidium iodide, hematoxylin-eosin, and isolectin B₄ staining to investigate the cellular damage, cytoarchitecture, and microglia activation. Whereas Equicel^® led to a neutral pH, Tabotamp^® (pH 2.8) and Equitamp^® (pH 4.8) caused a significant reduction of pH (p < 0.001). Equicel^® and Tabotamp^® increased cytotoxicity significantly in several cell lines (p < 0.01). On OHSC, Tabotamp^® and Equicel^® led to a stronger and deeper damage to the neuronal tissue than Equitamp^® or gauze (p < 0.01). Equicel^® increased strongly the number of microglia cells after 24 h (p < 0.001). Microglia cells were not detectable after Tabotamp^® treatment, presumably due to an artifact caused by strong pH reduction. In summary, our data imply the use of Equicel^®, Tabotamp^® or Equitamp^® for specific applications in distinct clinical settings depending on their localization or tissue properties.

Impact of cochlear ablation on calbindin and synaptophysin in the gerbil medial nucleus of the trapezoid body before hearing onset

Spontaneous bursting activity is already generated in the cochlea before hearing onset and represents an important condition of the functional and anatomical organization of auditory brainstem nuclei. In the present study, cochlea ablation induced changes were characterized in auditory brainstem nuclei indirectly innervated by auditory nerve fibers before hearing onset. In Meriones unguiculatus immunohistochemical labeling of calbindin-D28k (CB) and synaptophysin (SYN) were performed. The influence of cochlea-ablation on CB or SYN was analyzed by considering their differential immunoreaction during development. During the normal postnatal development, CB was first detected in somata of the medial nucleus of the trapezoid body (MNTB) at postnatal day (P)4. The immunoreaction increased gradually in parallel to the appearance of CB-immunoreactive terminal fields in distinct superior olivary complex (SOC) nuclei. Cochlear removal at P5 or P9 in animals with 24 and 48 h survival times resulted in an increase in somatic CB-labeling in the lesioned MNTB including terminal fields compared to the non-lesioned MNTB. SYN-immunolabeling was first detected at P0 and began to strongly encircle the MNTB neurons at P4. A further progression was observed with age. Cochlear ablation resulted in a significant reduction of SYN-labeled MNTB areas of P5-cochlea-ablated gerbils after 48 h post-lesion. In P9 cochlea-ablated gerbils, a redistribution of SYN-positive terminals was seen after 24 and 48 h. Taken together, the destruction of cochlea differentially influences CB- and SYN-labeling in the MNTB, which should be considered in association with different critical periods before hearing onset.

THC Reduces Ki67-Immunoreactive Cells Derived from Human Primary Glioblastoma in a GPR55-Dependent Manner

Glioblastoma (GBM) is the most frequent malignant tumor of the central nervous system in humans with a median survival time of less than 15 months. ∆⁹-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the best-characterized components of Cannabis sativa plants with modulating effects on cannabinoid receptors 1 and 2 (CB₁ and CB₂) and on orphan receptors such as GPR18 or GPR55. Previous studies have demonstrated anti-tumorigenic effects of THC and CBD in several tumor entities including GBM, mostly mediated via CB₁ or CB₂. In this study, we investigated the non-CB₁/CB₂ effects of THC on the cell cycle of GBM cells isolated from human tumor samples. Cell cycle entry was measured after 24 h upon exposure by immunocytochemical analysis of Ki67 as proliferation marker. The Ki67-reducing effect of THC was abolished in the presence of CBD, whereas CBD alone did not cause any changes. To identify the responsible receptor for THC effects, we first characterized the cells regarding their expression of different cannabinoid receptors: CB₁, CB₂, GPR18, and GPR55. Secondly, the receptors were pharmacologically blocked by application of their selective antagonists AM281, AM630, O-1918, and CID16020046 (CID), respectively. All examined cells expressed the receptors, but only in presence of the GPR55 antagonist CID was the THC effect diminished. Stimulation with the GPR55 agonist lysophosphatidylinositol (LPI) revealed similar effects as obtained for THC. The LPI effects were also inhibited by CBD and CID, confirming a participation of GPR55 and suggesting its involvement in modifying the cell cycle of patient-derived GBM cells.

The Effect of Resveratrol on Mitochondrial Function in Myoblasts of Patients with the Common m.3243A>G Mutation

Mitochondrial function is essential for ATP-supply, especially in response to different cellular stressors. Increased mitochondrial biogenesis resulting from caloric restriction (CR) has been reported. Resveratrol (RSV) is believed to mimic the physiological effects of CR mainly via a sirtuin (SIRT) 1-dependent pathway. The effect of RSV on the physiological function of mitochondrial respiratory complexes was evaluated using a Seahorse XF96. Myoblasts of five patients harboring the m.3243A>G mutation and five controls were analyzed. The relative expression of several genes involved in mitochondrial biogenesis was evaluated for a better understanding of the coherent mechanisms. Additionally, media-dependent effects of nutritional compounds and hormonal restrictions (R) on myoblasts from patients and controls in the presence or absence of RSV were investigated. Culturing of myoblasts under these conditions led to an upregulation of almost all the investigated genes compared to normal nutrition. Under normal conditions, there was no positive effect of RSV on mitochondrial respiration in patients and controls. However, under restricted conditions, the respiratory factors measured by Seahorse were improved in the presence of RSV. Further studies are necessary to clarify the involved mechanisms and elucidate the controversial effects of resveratrol on SIRT1 and SIRT3 expression.

Androstenedione changes steroidogenic activity of SGBS cells

The rapid increase of obesity during the last decades and its future prospects are alarming. Besides the general discussed causes of obesity, the 'Developmental Origins of Health and Disease' (DOHaD) hypothesis received more attention in recent years. This hypothesis postulates an adverse influence during early development that programs the unborn child for metabolic dysfunctions later in life. Childhood obesity - an as much increasing problem - can be predisposed by maternal overweight and diabetes. Both, obesity and hyperinsulinemia are major causes of female hyperandrogenemia. As predicted by the DOHaD hypothesis and shown in animal models, developmental androgen excess can lead to metabolic abnormalities in offspring. In this study, we investigated, if androgen exposure adversely affects the adipogenic differentiation of preadipocytes and the endocrine function of adult adipocytes. The human SGBS preadipocyte model was used to affirm the de novo biosynthesis of steroid hormones under normal adipogenesis conditions. Normal adipogenesis was paralleled by an increase of corticosteroids and androgens, whereas estrogen remained at a steady level. Treatment with androstenedione had no effect on SGBS proliferation and differentiation, but adult adipocytes exhibited a significant higher accumulation of triglycerides. Progesterone (up to 2-fold), testosterone (up to 38-fold) and cortisone (up to 1.4-fold) - but not cortisol - were elevated by androstenedione administration in adult adipocytes. Estrogen was not altered. Data suggest that androgen does not negatively influence adipogenic differentiation, but steroidogenic function of SGBS adipocytes.

MACC1 driven alterations in cellular biomechanics facilitate cell motility in glioblastoma

Background

Metastasis-associated in colon cancer 1 (MACC1) is an established marker for metastasis and tumor cell migration in a multitude of tumor entities, including glioblastoma (GBM). Nevertheless, the mechanism underlying the increased migratory capacity in GBM is not comprehensively explored.

Methods

We performed live cell and atomic force microscopy measurements to assess cell migration and mechanical properties of MACC1 overexpressing GBM cells. We quantified MACC1 dependent dynamics of 3D aggregate formation. For mechanistic studies we measured the expression of key adhesion molecules using qRT-PCR, and MACC1 dependent changes in short term adhesion to fibronectin and laminin. We then determined changes in sub-cellular distribution of integrins and actin in dependence of MACC1, but also in microtubule and intermediate filament organization.

Results

MACC1 increased the migratory speed and elastic modulus of GBM cells, but decreased cell-cell adhesion and inhibited the formation of 3D aggregates. These effects were not associated with altered mRNA expression of several key adhesion molecules or altered short-term affinity to laminin and fibronectin. MACC1 did neither change the organization of the microtubule nor intermediate filament cytoskeleton, but resulted in increased amounts of protrusive actin on laminin.

Conclusion

MACC1 overexpression increases elastic modulus and migration and reduces adhesion of GBM cells thereby impeding 3D aggregate formation. The underlying molecular mechanism is independent on the organization of microtubules, intermediate filaments and several key adhesion molecules, but depends on adhesion to laminin. Thus, targeting re-organization of the cytoskeleton and cell motility via MACC1 may offer a treatment option to impede GBM spreading.

Evaluation of machine learning models for automatic detection of DNA double strand breaks after irradiation using a γH2AX foci assay

Ionizing radiation induces amongst other the most critical type of DNA damage: double-strand breaks (DSBs). Efficient repair of such damage is crucial for cell survival and genomic stability. The analysis of DSB associated foci assays is often performed manually or with automatic systems. Manual evaluation is time consuming and subjective, while most automatic approaches are prone to changes in experimental conditions or to image artefacts. Here, we examined multiple machine learning models, namely a multi-layer perceptron classifier (MLP), linear support vector machine classifier (SVM), complement naive bayes classifier (cNB) and random forest classifier (RF), to correctly classify γH2AX foci in manually labeled images containing multiple types of artefacts. All models yielded reasonable agreements to the manual rating on the training images (Matthews correlation coefficient >0.4). Afterwards, the best performing models were applied on images obtained under different experimental conditions. Thereby, the MLP model produced the best results with an F1 Score >0.9. As a consequence, we have demonstrated that the used approach is sufficient to mimic manual counting and is robust against image artefacts and changes in experimental conditions.

The endocrine disruptor DEHP and the ECS: analysis of a possible crosstalk

Studies of the last decade associated the environmental contamination by di-(2-ethylhexyl)-phthalate (DEHP) with obesity and endocrine malfunction. DEHP was found to interact with several receptors - among them are receptors of the endocannabinoid system (ECS) with high expression levels in adipose tissue. Furthermore, the correlation for BMI and body fat to the serum endocannabinoid level raises the question if the obesogenic and endocrine-disrupting DEHP effects are mediated via the ECS. We therefore characterized the ECS in a human cell model of adipogenesis using the SGBS preadipocytes to subsequently investigate if DEHP exposure affects the intrinsic ECS. The receptors of the ECS and the endocannabinoid-metabolizing enzymes were upregulated during normal adipogenesis, accompanied by an increasing secretion of the adipokines adiponectin and leptin. DEHP affected the secretion of both adipokines but not the ECS, suggesting DEHP to alter the endocrine function of adipocytes without the involvement of the intrinsic ECS.

Abnormal Cannabidiol Affects Production of Pro-Inflammatory Mediators and Astrocyte Wound Closure in Primary Astrocytic-Microglial Cocultures

Abnormal cannabidiol (abn-CBD) exerts neuroprotective effects in vivo and in vitro. In the present study, we investigated the impact of abn-CBD on the glial production of proinflammatory mediators and scar formation within in vitro models. Primary astrocytic-microglial cocultures and astrocytic cultures from neonatal C57BL/6 mice and CB2 receptor knockout mice were stimulated with lipopolysaccharide (LPS), and the concentrations of tumor necrosis factor α (TNFα), interleukin-6 (IL-6) and nitrite were determined. Furthermore, we performed a live cell microscopy-based scratch-wound assay. After LPS stimulation, TNFα, IL-6 and nitrite production was more strongly increased in cocultures than in isolated astrocytes. Abn-CBD treatment attenuated the LPS-induced production of TNFα and nitrite in cocultures, while IL-6 production remained unaltered. In isolated astrocytes, only LPS-induced TNFα production was reduced by abn-CBD. Similar effects were observed after abn-CBD application in cocultures of CB2 knockout mice. Interestingly, LPS-induced TNFα and nitrite levels were far lower in CB2 knockout cultures compared to wildtypes, while IL-6 levels did not differ. In the scratch-wound assay, treatment with abn-CBD decelerated wound closure when microglial cells were present. Our data shows a differential role of abn-CBD for modulation of glial inflammation and astrocytic scar formation. These findings provide new explanations for mechanisms behind the neuroprotective potential of abn-CBD.

Impact of cochlear ablation on calretinin and synaptophysin in the gerbil anteroventral cochlear nucleus before the hearing onset

Mammalian auditory system undergoes many structural and functional modifications during postnatal development, which are dependent on the relationship between auditory nerve fibers and their nuclei. In the present study, the cochlea of Meriones unguiculatus was ablated unilaterally on postnatal day 5 or 9 (P5 or P9), before the onset of hearing. Histochemical analysis of synaptophysin (SYN) and calretinin (CR) in anterior anteroventral cochlear nucleus (AVCN-A) was performed to analyze whether unilateral cochlea ablation induces changes in the auditory terminal endings and somata of spherical bushy cells (SBCs). During the period of postnatal development, CR-labeling was evident in somata of SBCs and in auditory nerve terminals. SYN was most apparent in puncta encircled cell bodies, progressing with age. Cochlear removal at P5 induced a decrease in CR-labeling in SBCs somata 6 h and 48 h post-lesion; whereas, ablation at P9 increased the somatic CR-labeling in the lesioned AVCN-A after 24 and 48 h post-lesion. The SYN-labeled synaptic puncta were remarkably reduced in the AVCN-A of P5- and P9-cochlea-ablated gerbils with stronger effects in P5 animals (a 50% reduction after 48 h). Interestingly, a significant increase in the SYN-immunolabeled puncta was found after 48 h compared to 24 h in the lesioned AVCN-A of P9 gerbils, indicating reactive synaptogenesis. Our study shows, that following the destruction of the cochlea at different postnatal periods, the CR- and SYN-labeling are differentially influenced in the AVCN-A, which in turn coincides with different critical developmental periods before the onset of hearing.

Materials and manufacturing perspectives in engineering heart valves: a review

Valvular heart diseases (VHD) are a major health burden, affecting millions of people worldwide. The treatments for such diseases rely on medicine, valve repair, and artificial heart valves including mechanical and bioprosthetic valves. Yet, there are countless reports on possible alternatives noting long-term stability and biocompatibility issues and highlighting the need for fabrication of more durable and effective replacements. This review discusses the current and potential materials that can be used for developing such valves along with existing and developing fabrication methods. With this perspective, we quantitatively compare mechanical properties of various materials that are currently used or proposed for heart valves along with their fabrication processes to identify challenges we face in creating new materials and manufacturing techniques to better mimick ​the performance of native heart valves.