Magnetic nanoparticles in primary neural cell cultures are mainly taken up by microglia

<p>Abstract</p> <p>Background</p> <p>Magnetic nanoparticles (MNPs) offer a large range of applications in life sciences. Applications in neurosciences are one focus of interest. Unfortunately, not all groups have access to nanoparticles or the possibility to develop and produce them for their applications. Hence, they have to focus on commercially available particles. Little is known about the uptake of nanoparticles in primary cells. Previously studies mostly reported cellular uptake in cell lines. Here we present a systematic study on the uptake of magnetic nanoparticles (MNPs) by primary cells of the nervous system.</p> <p>Results</p> <p>We assessed the internalization in different cell types with confocal and electron microscopy. The analysis confirmed the uptake of MNPs in the cells, probably with endocytotic mechanisms. Furthermore, we compared the uptake in PC12 cells, a rat pheochromocytoma cell line, which is often used as a neuronal cell model, with primary neuronal cells. It was found that the percentage of PC12 cells loaded with MNPs was significantly higher than for neurons. Uptake studies in primary mixed neuronal/glial cultures revealed predominant uptake of MNPs by microglia and an increase in their number. The number of astroglia and oligodendroglia which incorporated MNPs was lower and stable. Primary mixed Schwann cell/fibroblast cultures showed similar MNP uptake of both cell types, but the Schwann cell number decreased after MNP incubation. Organotypic co-cultures of spinal cord slices and peripheral nerve grafts resembled the results of the dispersed primary cell cultures.</p> <p>Conclusions</p> <p>The commercial MNPs used activated microglial phagocytosis in both disperse and organotypic culture systems. It can be assumed that <it>in vivo </it>application would induce immune system reactivity, too. Because of this, their usefulness for <it>in vivo </it>neuroscientific implementations can be questioned. Future studies will need to overcome this issue with the use of cell-specific targeting strategies. Additionally, we found that PC12 cells took up significantly more MNPs than primary neurons. This difference indicates that PC12 cells are not a suitable model for natural neuronal uptake of nanoparticles and qualify previous results in PC12 cells.</p

Selection of reference genes for quantitative real-time PCR in a rat asphyxial cardiac arrest model

<p>Abstract</p> <p>Background</p> <p>Cardiac arrest, and the associated arrest of blood circulation, immediately leads to permanent brain damage because of the exhaustion of oxygen, glucose and energy resources in the brain. Most hippocampal CA1 neurons die during the first week post the insult. Molecular data concerning the recovery after resuscitation are sparse and limited to the early time period. Expression analysis of marker genes via quantitative real-time RT-PCR enables to follow up the remodeling process. However, proper validation of the applied normalization strategy is a crucial prerequisite for reliable conclusions.</p> <p>Therefore, the present study aimed to determine the expression stability of ten commonly used reference genes (<it>Actb</it>, actin, beta; <it>B2m</it>, beta-2 microglobulin;<it>CypA</it>, cyclophilin A; <it>Gapdh</it>, glyceraldehyde-3-phosphate dehydrogenase; <it>Hprt</it>, hypoxanthine guanine phosphoribosyl transferase; <it>Pgk1</it>, phosphoglycerate kinase 1; <it>Rpl13a</it>, ribosomal protein L13A; <it>Sdha</it>, succinat dehydrogenase complex, subunit a, flavoprotein (Fp); <it>Tbp</it>, TATA box binding protein; <it>Ywhaz</it>, tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, zeta polypeptide) in the rat hippocampus four, seven and twenty-one days after cardiac arrest. Moreover, experimental groups treated with the anti-inflammatory and anti-apoptotic drug minocycline have been included in the study as well.</p> <p>Results</p> <p>The microglial marker <it>Mac-1</it>, used as a target gene to validate the experimental model, was found to be upregulated about 10- to 20-fold after cardiac arrest.</p> <p>Expression stability of candidate reference genes was analyzed using geNorm and NormFinder software tools. Several of these genes behave rather stable. <it>CypA </it>and <it>Pgk1 </it>were identified by geNorm as the two most stable genes 4 and 21 days after asphyxial cardiac arrest, <it>CypA </it>and <it>Gapdh </it>at 7 days post treatment. <it>B2m </it>turned out to be the most variable candidate reference gene, being about 2-fold upregulated in the cardiac arrest treatment groups.</p> <p>Conclusion</p> <p>We have validated endogenous control genes for qRT-PCR analysis of gene expression in rat hippocampus after resuscitation from cardiac arrest. For normalization purposes in gene profiling studies a combination of <it>CypA </it>and <it>Pgk1 </it>should be considered 4 and 21 days post injury, whereas <it>CypA </it>and <it>Gapdh </it>is the best combination at 7 days. <it>CypA </it>is most favorable if restriction to a single reference gene for all time points is required.</p

NERVEN AUS DEM LABOR: DAS TISSUE ENGINEERING PERIPHERER NERVEN ZUR VERSORGUNG VON NERVENVERLETZUNGEN

Verletzungen peripherer Nerven sind häufiger als gemeinhin angenommen und werden in Deutschland noch nicht optimal behandelt. Die besten Vorraussetzungen für eine gute Rekonstruktion bietet die primäre mikrochirurgische Nervennaht. Bei Defekten wird ein körpereigenes Transplantat benötigt. Dessen Entnahme führt allerdings zu Funktionsausfällen. Unsere interdisziplinäre Forschungsgruppe aus Plastischen Chirurgen und Neurobiologen beschäftigt sich mit der labortechnischen Herstellung von Nervenersatzgewebe aus einer biogenen Trägermatrix und den nerveneigenen Hüllzellen (sog. Schwannsche Zellen), die die Regeneration der Nerven verbessern

Evidence for a wide extra-astrocytic distribution of S100B in human brain

BACKGROUND: S100B is considered an astrocytic in-situ marker and protein levels in cerebrospinal fluid (CSF) or serum are often used as biomarker for astrocytic damage or dysfunction. However, studies on S100B in the human brain are rare. Thus, the distribution of S100B was studied by immunohistochemistry in adult human brains to evaluate its cell-type specificity. RESULTS: Contrary to glial fibrillary acidic protein (GFAP), which selectively labels astrocytes and shows only faint ependymal immunopositivity, a less uniform staining pattern was seen in the case of S100B. Cells with astrocytic morphology were primarily stained by S100B in the human cortex, while only 20% (14–30%) or 14% (7–35%) of all immunopositive cells showed oligodendrocytic morphology in the dorsolateral prefrontal and temporal cortices, respectively. In the white matter, however, most immunostained cells resembled oligodendrocytes [frontal: 75% (57–85%); temporal: 73% (59–87%); parietal: 79% (62–89%); corpus callosum: 93% (86–97%)]. S100B was also found in ependymal cells, the choroid plexus epithelium, vascular endothelial cells, lymphocytes, and several neurones. Anti-myelin basic protein (MBP) immunolabelling showed an association of S100B with myelinated fibres, whereas GFAP double staining revealed a distinct subpopulation of cells with astrocytic morphology, which solely expressed S100B but not GFAP. Some of these cells showed co-localization of S100B and A2B5 and may be characterized as O2A glial progenitor cells. However, S100B was not detected in microglial cells, as revealed by double-immunolabelling with HLA-DR. CONCLUSION: S100B is localized in many neural cell-types and is less astrocyte-specific than GFAP. These are important results in order to avoid misinterpretation in the identification of normal and pathological cell types in situ and in clinical studies since S100B is continuously used as an astrocytic marker in animal models and various human diseases

Biocompatibility of Different Nerve Tubes

Bridging nerve gaps with suitable grafts is a major clinical problem. The autologous nerve graft is considered to be the gold standard, providing the best functional results; however, donor site morbidity is still a major disadvantage. Various attempts have been made to overcome the problems of autologous nerve grafts with artificial nerve tubes, which are “ready-to-use” in almost every situation. A wide range of materials have been used in animal models but only few have been applied to date clinically, where biocompatibility is an inevitable prerequisite. This review gives an idea about artificial nerve tubes with special focus on their biocompatibility in animals and humans

Effects of Antipsychotics on Dentate Gyrus Stem Cell Proliferation and Survival in Animal Models:A Critical Update

Schizophrenia is a complex psychiatric disorder. Although a number of different hypotheses have been developed to explain its aetiopathogenesis, we are far from understanding it. There is clinical and experimental evidence indicating that neurodevelopmental factors play a major role. Disturbances in neurodevelopment might result in alterations of neuroanatomy and neurochemistry, leading to the typical symptoms observed in schizophrenia. The present paper will critically address the neurodevelopmental models underlying schizophrenia by discussing the effects of typical and atypical antipsychotics in animal models. We will specifically discuss the vitamin D deficiency model, the poly I:C model, the ketamine model, and the postnatal ventral hippocampal lesion model, all of which reflect core neurodevelopmental issues underlying schizophrenia onset

Технологические решения для строительства эксплуатационной скважины методом горизонтально направленного бурения глубиной 1350 метров на Ашальчинском нефтяном месторождении (Республики Татарстан)

РЕФЕРАТ Выпускная квалификационная работа бакалавра содержит 80 стр., 14 рис., 47 табл., 31 источник, 2 приложения, 2-листа графического материала. Ключевые слова: Республика Татарстан, Шешминский горизонт, конструкция забоя, обсадная колонна , буровой раствор. Объектом работы является технология строительства эксплуатационной горизонтально направленной скважины для добычи нефти. Работа выполнена по геологическим условиям Ашальчинского нефтяного месторождения. В процессе исследования проводились обоснованные расчеты подбора ВЗД, буровые растворы, конструкция скважины, долота. По результатам работы была подобрана техника и технология расчета обустройства скважины глубиной 1350 метров. Экономическая эффективность заключается в небольшом залегании пласта, и введенные правительством РФ льготANNOTATION Final qualifying work of bachelor contains 80 p., 14 fig., 47 tab., 31 sources of literature, 2 annexes, 2 sheets of graphic material. Keywords: the republic of Tatarstan, Sheshminsky horizon, bottomhole design, casing column, drilling mud. The object of the work is the construction technology of operational horizontal oil well. The work is made according to the geological conditions of Ashalchinskoye oil field. The study carried out reasonable calculations selection of PDM motor, drilling mud, well design and drilling bit. As a result of the work engineering and technology calculation of well ties (1350 meters in deep) was selected. Cost-effectiveness is caused by shallow formation. The Russian government grants connected with MET for the production of superviscous oil. I