The Experts below are selected from a list of 10845 Experts worldwide ranked by ideXlab platform
Adriano Aguzzi - One of the best experts on this subject based on the ideXlab platform.
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The prion organotypic Slice Culture assay—POSCA
Nature Protocols, 2008Co-Authors: Jeppe Falsig, Adriano AguzziAbstract:Methods enabling prion replication ex vivo are important for advancing prion science. However, few such technologies exist and many prion strains are intractable with them. Here, we describe a prion organotypic Slice Culture assay (POSCA), which allows for prion amplification and titration ex vivo under conditions that closely resemble intracerebral infection. Organotypic Slices are incubated with infectious inoculum as free-floating sections, washed and Cultured for up to 8 weeks. Slice Cultures are a rich source of protein or RNA and allow for stringent comparisons between uninfected and prion-infected samples generated from the same mouse. Thirty-five days after contact with prions, cerebellar Slices have amplified PrP^Sc quantitatively similar to that seen in vivo , but accelerated fivefold. The POSCA detects replication of specific prion strains from disparate sources, including bovines and ovines, with variable efficiency. The Culture procedure and prion infection can be performed in 8 h.
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The prion organotypic Slice Culture assay--POSCA.
Nature Protocols, 2008Co-Authors: Jeppe Falsig, Adriano AguzziAbstract:Methods enabling prion replication ex vivo are important for advancing prion science. However, few such technologies exist and many prion strains are intractable with them. Here, we describe a prion organotypic Slice Culture assay (POSCA), which allows for prion amplification and titration ex vivo under conditions that closely resemble intracerebral infection. Organotypic Slices are incubated with infectious inoculum as free-floating sections, washed and Cultured for up to 8 weeks. Slice Cultures are a rich source of protein or RNA and allow for stringent comparisons between uninfected and prion-infected samples generated from the same mouse. Thirty-five days after contact with prions, cerebellar Slices have amplified PrP(Sc) quantitatively similar to that seen in vivo, but accelerated fivefold. The POSCA detects replication of specific prion strains from disparate sources, including bovines and ovines, with variable efficiency. The Culture procedure and prion infection can be performed in 8 h.
Morten Meyer - One of the best experts on this subject based on the ideXlab platform.
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a brain Slice Culture model for studies of endogenous and exogenous precursor cell migration in the rostral migratory stream
Brain Research, 2009Co-Authors: Mette Tanvig, Morten Blaabjerg, Rikke K Andersen, Ana Villa, Ann Mari Rosager, Frantz Rom Poulsen, Alberto Martinezserrano, Jens Zimmer, Morten MeyerAbstract:Abstract The rostral migratory stream (RMS) is the main pathway by which newly born subventricular zone (SVZ) cells reach the olfactory bulb (OB) in rodents. This migration has been well studied in vivo , but an organotypic in vitro model would facilitate more experimental investigations. Here we introduce a Slice Culture preparation of the rat forebrain including en suite the rostral part of the lateral ventricle, the RMS and the OB. The preparation was validated with regard to endogenous cell proliferation and migration by tracking bromodeoxyuridine (BrdU)-labelled cells in newly established and 3 and 6 week old Cultures. For testing the migratory abilities of exogenous precursor cells, rat SVZ neurospheres and human neural (HNS1 cells) and mesenchymal (hMSC-TERT) stem cell lines were micrografted to the rostral SVZ of 1 and 7 day old Cultures. Two weeks later graft derivatives were identified by immunohistochemical staining for human nuclei (HNS1/hMSC-TERT cells) and BrdU (HNS1 cells/neurospheres). Numerous HNS1 cells and BrdU-positive neurosphere cells were found in the RMS. Having reached the OB, subpopulations of the cells expressed the astroglial markers glial fibrillary acidic protein/hAM and the neuronal markers NeuN/tyrosine hydroxylase. Interestingly, the hMSC-TERT cells remained at the implantation site, demonstrating a diversity in migratory capability of different precursor cells. In conclusion, the RMS in rat forebrain Slice Cultures retains its ability to support migration of endogenous and exogenous neural precursors, making the Cultures highly feasible for studies of conditions and factors regulating cell migration.
Michael Frotscher - One of the best experts on this subject based on the ideXlab platform.
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the rostral migratory stream generates hippocampal ca1 pyramidal like neurons in a novel organotypic Slice co Culture model
Biology Open, 2015Co-Authors: Ilyas Singec, Rolf Knoth, Imre Vida, Michael FrotscherAbstract:The mouse subventricular zone (SVZ) generates large numbers of neuroblasts, which migrate in a distinct pathway, the rostral migratory stream (RMS), and replace specific interneurons in the olfactory bulb (OB). Here, we introduce an organotypic Slice Culture model that directly connects the RMS to the hippocampus as a new destination. RMS neuroblasts widely populate the hippocampus and undergo cellular differentiation. We demonstrate that RMS cells give rise to various neuronal subtypes and, surprisingly, to CA1 pyramidal neurons. Pyramidal neurons are typically generated before birth and are lost in various neurological disorders. Hence, this unique Slice Culture model enables us to investigate their postnatal genesis under defined in vitro conditions from the RMS, an unanticipated source for hippocampal pyramidal neurons.
Alex Yeechen Huang - One of the best experts on this subject based on the ideXlab platform.
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brain Slice Culture demonstrates expedited cell traficking in the presence of fractalkine in a medulloblastoma tumor microenvironment model
Journal of Immunology, 2016Co-Authors: William H Tomaszewski, Rodney Dixon Dorand, Agne Petrosiute, Alex Yeechen HuangAbstract:20% of childhood brain tumors are medulloblastomas (MB), and the five-year survival rate can be as low as 60%. The interaction between MB and native immune cells are not well understood, and identifying methods of crosstalk could produce better outcomes for patients. Fractalkine (FKN) is a ligand for the receptor CX 3 CR1 that plays an inhibitory role in the brain’s immune system by keeping microglia quiescent. Normally, FKN is surface bound and expressed by neurons and astrocytes, but under inflammatory conditions FKN is secreted to serve as a chemoattractant. Preliminary work in our lab shows that FKN is produced by MB and may act as a decoy to maintain microglial quiescence leading to immune escape. Therefore we investigated FKN signaling and microglial kinetics ex vivo utilizing organotypic brain Slice Culture coupled with real time 2-photon laser scanning microscopy. To differentiate microglia from MB, CX 3 CR1 +/GFP or CX 3 CR1 GFP/GFP knock-in mice were sacrificed, and the brain was removed and sectioned. Slices were collected and Cultured on inserts in an incubation chamber during imaging. To determine baseline activity, CX 3 CR1 +/GFP and CX 3 CR1 GFP/GFP brain Slices were imaged over 48 hours. MB tumor cells, labelled with SNARF-1, were added to the Cultures and imaged over the same time course. Images were processed to differentiate the motility of microglia and tumors. We found that microglia from CX 3 CR1 +/GFP moved slower than microglia from CX 3 CR1 GFP/GFP at baseline and in the presence of tumor. Furthermore, we found that MB moved faster in CX 3 CR1 GFP/GFP Slices, suggesting that fractalkine plays a role in the migration of MB.
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organotypic brain Slice Culture reveals fractalkine signaling alters the kinetics of microglia and medulloblastoma migration in the cns tumor microenvironment tum7p 953
Journal of Immunology, 2014Co-Authors: Dixon Dorand, Deborah S Barkauskas, Joseph Nthale, Jay T Myers, Agne Petrositue, Alex Yeechen HuangAbstract:Medulloblastoma (MB) is the most common pediatric Central Nervous System (CNS) malignancy and is capable of metastasis to distant sites. Little is known about the interactions between MB and the highly selective CNS immune environment; therefore, we investigated the role of microglia, the endogenous immune cells of the CNS, in MB microenvironment. Microglia reside in the brain parenchyma and help maintain the homeostatic immunosuppressive environment partially due to their expression of CX3CR1 for which Fractalkine (FKN) is the only known ligand. FKN is constitutively expressed by neurons and astrocytes leading to tonic inhibition of microglial activation. Our Enzyme Linked Immunosorbent Assay (ELISA) results demonstrate that MB can produce as much as 2.5 ng/mL/1x106 tumor cells/24hrs of FKN. Organotypic brain Slice Culture coupled with 2 photon laser scanning microscopy reveals that genetic deletion of CX3CR1 results in an increase basal microglia speed from 0.071 μm/min in CX3CR1+/- mice to 0.123 μm/min in CX3CR1-/- mice. In the presence of MB, microglia speed increases to 0.154 μm/min in CX3CR1+/- mice to 0.203 μm/min in CX3CR1-/- mice. This data supports the role of FKN signaling as an inhibitor of microglial activation. Interestingly, MB tumor cells move faster in brain Slices of CX3CR1-/- mice (0.301 μm/min) compared to CX3CR1+/- mice (0.144 μm/min), further suggesting that FKN signaling may play a role in MB invasion as well as microglia movement.
Misook Chang - One of the best experts on this subject based on the ideXlab platform.
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transplantation of mesenchymal stem cells enhances axonal outgrowth and cell survival in an organotypic spinal cord Slice Culture
Neuroscience Letters, 2009Co-Authors: Jungsun Cho, Hwanwoo Park, Sangkyu Park, Sangho Roh, Sookyung Kang, Kisuk Paik, Misook ChangAbstract:Mesenchymal stem cells (MSCs) have demonstrated a measurable therapeutic effect following transplantation into animal models of spinal cord injury. However, the mechanism(s) by which transplanted cells promote nerve regeneration and/or functional recovery remains indeterminate. Several studies have suggested that MSCs promote tissue repair via secretion of trophic factors, but delineating the effect of such factors is difficult due to the complexity of the in vivo systems. Therefore, we developed an organotypic spinal cord Slice Culture system that can be sustained for sufficient periods of time in vitro to evaluate nerve regeneration as an ex vivo model of spinal cord injury. Using this model, we demonstrate that treatment of lumbar Slices of spinal cord with lysolecithin induced a significant degree of cell death and demyelination of nerve fibers, but that these effects were ameliorated to a significant extent following co-Culture of Slices with human MSCs (hMSCs). The results indicate that transplanted hMSCs alter the tissue microenvironment in a way that promotes survival of endogenous cells, including injured neurons, immature oligodendrocytes and oligodendrocyte progenitor cells. This ex vivo Culture system represents a useful tool to further dissect the mechanism(s) by which MSCs promote regeneration of injured nervous tissue.
