scholarly journals Chemical targeting of voltage sensitive dyes to specific cell types in the brain

2020 ◽  
Author(s):  
Tomas Fiala ◽  
Jihang Wang ◽  
Matthew Dunn ◽  
Se Joon Choi ◽  
Peter Sebej ◽  
...  
Keyword(s):  
Cell Types ◽  
Specific Cell ◽  
Voltage Sensitive Dyes ◽  
The Brain

scholarly journals Chemical targeting of voltage sensitive dyes to specific cell types in the brain

2020 ◽  
Author(s):  
Tomas Fiala ◽  
Jihang Wang ◽  
Matthew Dunn ◽  
Se Joon Choi ◽  
Peter Sebej ◽  
...  
Keyword(s):  
Cell Types ◽  
Specific Cell ◽  
Voltage Sensitive Dyes ◽  
The Brain

scholarly journals Chemical targeting of voltage sensitive dyes to specific cell types in the brain

2020 ◽  
Author(s):  
Tomas Fiala ◽  
Jihang Wang ◽  
Matthew Dunn ◽  
Sejoon Choi ◽  
Peter Sebej ◽  
...  
Keyword(s):  
Cell Types ◽  
Specific Cell ◽  
Voltage Sensitive Dyes ◽  
The Brain

scholarly journals The HIV-1 Transgenic Rat: Relevance for HIV Noninfectious Comorbidity Research

2020 ◽  
Vol 8 (11) ◽  
pp. 1643
Author(s):  
Frank Denaro ◽  
Francesca Benedetti ◽  
Myla D. Worthington ◽  
Giovanni Scapagnini ◽  
Christopher C. Krauss ◽  
...  
Keyword(s):  
Neuronal Degeneration ◽  
Cell Types ◽  
Transgenic Rat ◽  
Specific Cell ◽  
Rat Tissues ◽  
Local Production ◽  
Specific Tissue ◽  
Effective Models ◽  
The Brain ◽  
Hiv 1

HIV noninfectious comorbidities (NICMs) are a current healthcare challenge. The situation is further complicated as there are very few effective models that can be used for NICM research. Previous research has supported the use of the HIV-1 transgenic rat (HIV-1TGR) as a model for the study of HIV/AIDS. However, additional studies are needed to confirm whether this model has features that would support NICM research. A demonstration of the utility of the HIV-1TGR model would be to show that the HIV-1TGR has cellular receptors able to bind HIV proteins, as this would be relevant for the study of cell-specific tissue pathology. In fact, an increased frequency of HIV receptors on a specific cell type may increase tissue vulnerability since binding to HIV proteins would eventually result in cell dysfunction and death. Evidence suggests that observations of selective cellular vulnerability in this model are consistent with some specific tissue vulnerabilities seen in NICMs. We identified CXCR4-expressing cells in the brain, while specific markers for neuronal degeneration demonstrated that the same neural types were dying. We also confirm the presence of gp120 and Tat by immunocytochemistry in the spleen, as previously reported. However, we observed very rare positive cells in the brain. This underscores the point that gp120, which has been reported as detected in the sera and CSF, is a likely source to which these CXCR4-positive cells are exposed. This alternative appears more probable than the local production of gp120. Further studies may indicate some level of local production, but that will not eliminate the role of receptor-mediated pathology. The binding of gp120 to the CXCR4 receptor on neurons and other neural cell types in the HIV-1TGR can thus explain the phenomena of selective cell death. Selective cellular vulnerability may be a contributing factor to the development of NICMs. Our data indicate that the HIV-1TGR can be an effective model for the studies of HIV NICMs because of the difference in the regional expression of CXCR4 in rat tissues, thus leading to specific organ pathology. This also suggests that the model can be used in the development of therapeutic options.

Three-Dimensional Time-Lapse Digital Movie Analysis of the Developing Fruit Fly Eye in Organ Culture

1997 ◽  
Vol 3 (S2) ◽  
pp. 1129-1130
Author(s):  
John Archie Pollock ◽  
Bejon T. Maneckshana ◽  
Teresa E. Leonardo
Keyword(s):  
Organ Culture ◽  
Compound Eye ◽  
Eye Development ◽  
Larval Instar ◽  
Three Dimensional ◽  
Fruit Fly ◽  
Time Lapse ◽  
Cell Types ◽  
Specific Cell ◽  
The Brain

The compound eye of the fruit fly, Drosophila melanogaster, is composed of a highly ordered array of facets (FIG. 1), each containing a precise set of neurons and supporting cells. The eye arises during the third larval instar from an undifferentiated epithelium, the eye imaginai disc, which is connected to the brain via the optic stalk (FIG. 2). During eye development, movement of the morphogenetic furrow, progressive recruitment of specific cell types and the growth of photoreceptor axons into the brain are each dynamic processes that are routinely studied indirectly in fixed tissues. While stereotyped development and the ‘crystalline’ like structure of the eye facilitates this analysis, certain experiments are hindered by the inability to observe developmental processes as they occur. To overcome this limitation, we have combined organ culture with advanced microscopy tools to enable the observation of eye development in living tissue.

scholarly journals Unique Glycan Signatures Regulate Adeno-Associated Virus Tropism in the Developing Brain

2015 ◽  
Vol 89 (7) ◽  
pp. 3976-3987 ◽  
Author(s):  
Giridhar Murlidharan ◽  
Travis Corriher ◽  
H. Troy Ghashghaei ◽  
Aravind Asokan
Keyword(s):  
Polysialic Acid ◽  
Cell Types ◽  
Developing Brain ◽  
Specific Cell ◽  
Developmentally Regulated ◽  
Transport Pathways ◽  
Adeno Associated Virus ◽  
Viral Transport ◽  
The Central Nervous System ◽  
The Brain

ABSTRACTAdeno-associated viruses (AAV) are thought to spread through the central nervous system (CNS) by exploiting cerebrospinal fluid (CSF) flux and hijacking axonal transport pathways. The role of host receptors that mediate these processes is not well understood. In the current study, we utilized AAV serotype 4 (AAV4) as a model to evaluate whether ubiquitously expressed 2,3-linked sialic acid and the developmentally regulated marker 2,8-linked polysialic acid (PSA) regulate viral transport and tropism in the neonatal brain. Modulation of the levels of SA and PSA in cell culture studies using specific neuraminidases revealed possibly opposing roles of the two glycans in AAV4 transduction. Interestingly, upon intracranial injection into lateral ventricles of the neonatal mouse brain, a low-affinity AAV4 mutant (AAV4.18) displayed a striking shift in cellular tropism from 2,3-linked SA+ependymal lining to 2,8-linked PSA+migrating progenitors in the rostral migratory stream and olfactory bulb. In addition, this gain-of-function phenotype correlated with robust CNS spread of AAV4.18 through paravascular transport pathways. Consistent with these observations, altering glycan dynamics within the brain by coadministering SA- and PSA-specific neuraminidases resulted in striking changes to the cellular tropisms and transduction efficiencies of both parental and mutant vectors. We postulate that glycan signatures associated with host development can be exploited to redirect novel AAV vectors to specific cell types in the brain.IMPORTANCEViruses invade the CNS through various mechanisms. In the current study, we utilized AAV as a model to study the dynamics of virus-carbohydrate interactions in the developing brain and their impact on viral tropism. Our findings suggest that carbohydrate content can be exploited to regulate viral transport and tropism in the brain.

scholarly journals MRI of Capn15 knockout mice and analysis of Capn15 distribution reveal possible roles in brain development and plasticity

2019 ◽  
Author(s):  
Congyao Zha ◽  
Carole A Farah ◽  
Vladimir Fonov ◽  
David A. Rudko ◽  
Wayne S Sossin
Keyword(s):  
Brain Development ◽  
Knockout Mice ◽  
Brain Plasticity ◽  
Small Animal ◽  
Cell Types ◽  
Cysteine Proteases ◽  
Brain Regions ◽  
Conditional Knockout ◽  
Specific Cell ◽  
The Brain

AbstractPurposeThe non-classical Small Optic Lobe (SOL) family of calpains are intracellular cysteine proteases that are expressed in the nervous system and appear to play an important role in neuronal development in both Drosophila, where loss of this calpain leads to the eponymous small optic lobes, and in mouse and human, where loss of this calpain (Capn15) leads to eye anomalies. However, the brain regions where this calpain is expressed and the areas most affected by the loss of this calpain have not been carefully examined.ProceduresWe utilize an insert strain where lacZ is expressed under the control of the Capn15 promoter, together with immunocytochemistry with markers of specific cell types to address where Capn 15 is expressed in the brain. We use small animal MRI comparing WT, Capn15 knockout and Capn15 conditional knockout mice to address the brain regions that are affected when Capn 15 is not present, either in early development of the adult.ResultsCapn15 is expressed in diverse brain regions, many of them involved in plasticity such as the hippocampus, lateral amygdala and Purkinje neurons. Capn15 knockout mice have smaller brains, and present specific deficits in the thalamus and hippocampal regions. There are no deficits revealed by MRI in brain regions when Capn15 is knocked out after development.ConclusionsAreas where Capn15 is expressed in the adult are not good markers for the specific regions where the loss of Capn15 specifically affects brain development. Thus, it is likely that this calpain plays distinct roles in brain development and brain plasticity.

scholarly journals Immovable Object Meets Unstoppable Force? Dialogue Between Resident and Peripheral Myeloid Cells in the Inflamed Brain

2020 ◽  
Vol 11 ◽  
Author(s):  
Alanna G. Spiteri ◽  
Claire L. Wishart ◽  
Nicholas J. C. King
Keyword(s):  
Myeloid Cells ◽  
Cell Types ◽  
Brain Parenchyma ◽  
Specific Cell ◽  
Novel Treatments ◽  
Experimental Systems ◽  
Immune Mediated ◽  
Recent Developments ◽  
The Central Nervous System ◽  
The Brain

Inflammation of the brain parenchyma is characteristic of neurodegenerative, autoimmune, and neuroinflammatory diseases. During this process, microglia, which populate the embryonic brain and become a permanent sentinel myeloid population, are inexorably joined by peripherally derived monocytes, recruited by the central nervous system. These cells can quickly adopt a morphology and immunophenotype similar to microglia. Both microglia and monocytes have been implicated in inducing, enhancing, and/or maintaining immune-mediated pathology and thus disease progression in a number of neuropathologies. For many years, experimental and analytical systems have failed to differentiate resident microglia from peripherally derived myeloid cells accurately. This has impeded our understanding of their precise functions in, and contributions to, these diseases, and hampered the development of novel treatments that could target specific cell subsets. Over the past decade, microglia have been investigated more intensively in the context of neuroimmunological research, fostering the development of more precise experimental systems. In light of our rapidly growing understanding of these cells, we discuss the differential origins of microglia and peripherally derived myeloid cells in the inflamed brain, with an analysis of the problems resolving these cell types phenotypically and morphologically, and highlight recent developments enabling more precise identification.

Human Mesenchymal Stem Cells Differentiate Promptly into Tissue-Specific Cell Types without Cell Fusion, Mitochondrial or Membrane Vesicular Transfer in Fetal Sheep.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 436-436 ◽  
Author(s):  
Evan J. Colletti ◽  
Judith A. Airey ◽  
Esmail D. Zanjani ◽  
Christopher D. Porada ◽  
Graça Almeida-Porada
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Cell Fusion ◽  
Human Mesenchymal Stem Cells ◽  
Cell Types ◽  
Specific Cell ◽  
Type I ◽  
Fetal Sheep ◽  
Tissue Specific ◽  
The Brain

Abstract Despite the exciting reports regarding the ability of human mesenchymal stem cells (MSC) to differentiate into different cells of different organs, the mechanism by which this process occurs remains controversial. Several possible explanations have been put forth as an alternative to the existence of a true differentiation mechanism. We previously showed that MSC, at a single cell level, are able to differentiate into cells of different germ cell layers. In the present study, we investigated whether transfer of mitochondria or membrane-derived vesicles between cells and/or cell fusion participate in the events that lead to the change of phenotype of MSC upon transplantation (Tx). To this end, 54 sheep fetuses (55–60 gestational days) were Tx intra-peritoneally with Stro-1+,CD45−, Gly-A- MSC labeled prior to Tx with either CFSE, that irreversibly couples to both intracellular and cell-surface proteins, or DiD that efficiently labels all cell membranes and intracellular organelles, such as mitochondria. Evaluation of the recipients’ different organs started at 20h post-Tx and continued at 25,30,40,60 and 120h. MSC reached the liver at 25h post-Tx (0.033%±0.0) with maximal engraftment at 40h (0.13%±0.02). MSC were first detected in the lung (0.028%±0.0) and brain (0.034%±0.0) at 30h and 40h respectively. In the brain, engraftment peaked at 60 hours post-Tx (0.08%±0.0) and in the lung at 120h (0.09%±0.01). Normalization of the number of engrafted cells per tissue mass and number of Tx cells revealed that 26% of the Tx MSC reached the lung; 2% the liver; and 3% the brain. Since the decreasing number of CFSE+ and DiD+ cells detected after 120h could be due to cell division, Ki67 staining was performed and revealed that 85–95% of the engrafted cells proliferated upon lodging in the organs, and divided throughout the evaluation period. To determine MSC differentiative timeline, confocal microscopy was performed to assess whether CFSE+ or DiD+ cells expressed tissue-specific markers (MSC were negative for these markers prior to transplant) within the engrafted organs. In the liver at 25h post-Tx, all CFSE+ or DiD+ cells co-expressed alpha-fetoprotein, demonstrating the rapid switch from an MSC to a fetal hepatocyte-like phenotype. In the lung, co-localization of pro-surfactant protein and CFSE/DiD was first detected at 30h post-Tx, but cells remained negative for Caveolin1; a phenotype that is consistent with differentiation to a type II epithelial cell, but not to a more mature type I. In the brain, MSC expressed Tau promptly, but synaptophysin expression was not detected until 120h. In situ hybridization on serial sections using either a human- or sheep-specific probe, with simultaneous visualization of CFSE+ or DiD+ cells allowed us to show that no membrane or mitochondrial transfer had occurred, since none of the sheep cells contained CFSE or DiD, and all of the dye+ cells hybridized only to the human probe. Furthermore, this combined methodology enabled us to determine that differentiation to all of the different cell types had occurred in the absence of cell fusion. In conclusion, MSC engraft multiple tissues rapidly, undergo proliferation, and give rise to tissue-specific cell types in the absence of cellular fusion or the transfer of mitochondria or membrane vesicles.

scholarly journals Transposon-mediated, cell type-specific transcription factor recording in the mouse brain

2019 ◽  
Author(s):  
Alexander J. Cammack ◽  
Arnav Moudgil ◽  
Tomas Lagunas ◽  
Michael J. Vasek ◽  
Mark Shabsovich ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mouse Brain ◽  
Regulation Of Gene Expression ◽  
Cell Types ◽  
Mouse Tissue ◽  
Specific Cell ◽  
Cell Type ◽  
Cell Fate Decisions ◽  
Cell Type Specific ◽  
The Brain

AbstractTranscription factors (TFs) play a central role in the regulation of gene expression, controlling everything from cell fate decisions to activity dependent gene expression. However, widely-used methods for TF profiling in vivo (e.g. ChIP-seq) yield only an aggregated picture of TF binding across all cell types present within the harvested tissue; thus, it is challenging or impossible to determine how the same TF might bind different portions of the genome in different cell types, or even to identify its binding events at all in rare cell types in a complex tissue such as the brain. Here we present a versatile methodology, FLEX Calling Cards, for the mapping of TF occupancy in specific cell types from heterogenous tissues. In this method, the TF of interest is fused to a hyperactive piggyBac transposase (hypPB), and this bipartite gene is delivered, along with donor transposons, to mouse tissue via a Cre-dependent adeno-associated virus (AAV). The fusion protein is expressed in Cre-expressing cells where it inserts transposon “Calling Cards” near to TF binding sites. These transposons permanently mark TF binding events and can be mapped using high-throughput sequencing. Alternatively, unfused hypPB interacts with and records the binding of the super enhancer (SE)-associated bromodomain protein, Brd4. To demonstrate the FLEX Calling Card method, we first show that donor transposon and transposase constructs can be efficiently delivered to the postnatal day 1 (P1) mouse brain with AAV and that insertion profiles report TF occupancy. Then, using a Cre-dependent hypPB virus, we show utility of this tool in defining cell type-specific TF profiles in multiple cell types of the brain. This approach will enable important cell type-specific studies of TF-mediated gene regulation in the brain and will provide valuable insights into brain development, homeostasis, and disease.

scholarly journals Chemical Targeting of Voltage Sensitive Dyes to Specific Cell Types in the Brain

2018 ◽  
Author(s):  
Tomas Fiala ◽  
Jihang Wang ◽  
Matthew Dunn ◽  
Peter Šebej ◽  
Ekeoma Nwadibia ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Fluorescent Dyes ◽  
Brain Slices ◽  
High Sensitivity ◽  
Specific Cell ◽  
Specific Targeting ◽  
Endogenous Expression ◽  
The Impact ◽  
Voltage Sensitive Dyes ◽  
The Brain

Voltage sensitive fluorescent dyes (VSDs) are important tools for probing signal transduction in neurons and other excitable cells. These sensors, rendered highly lipophilic to anchor the conjugated p-wire molecular framework in the membrane, offer several favorable functional parameters including fast response kinetics and high sensitivity to membrane potential changes. The impact of VSDs has however been limited due to the lack of cell-specific targeting methods in brain tissue or living animals. We address this key challenge by introducing a non-genetic molecular platform for cell and molecule specific targeting of synthetic voltage sensitive dyes in the brain. We employ a dextran polymer particle to overcome the inherent lipophilicity of voltage sensitive dyes by dynamic encapsulation and target the construct to specific axonal extensions using the monoamine transporter ligand dichloropane. VoLDeMo (<u>Vo</u>ltage Sensor-<u>L</u>igand-<u>De</u>xtran Targeted to <u>Mo</u>noaminergic Neurons) probes label dense dopaminergic axons in the mouse striatum and sparse noradrenergic axons in the mouse cortex in acute brain slices. We also demonstrate in whole adult <i>Drosophila</i> brains that VoLDeMo targeting is ligand dependent. VoLDeMo variants bearing either a classical electrochromic ANEP dye or state-of-the-art VoltageFluor dye respond to membrane potential changes in a similar manner to the parent dyes, as demonstrated by whole-cell patch recording. The VoLDeMo platform enables targeting of diffusible VSD probes to specific neuronal cells using endogenous expression levels of native components of neurotransmission machinery. We envision that modularity of our platform will enable its application to a variety of molecular targets (other receptors and covalent labeling-based tags) and sensors (including those in other imaging modalities), as well as lipophilic drugs and signaling modulators. This work demonstrates the feasibility of a chemical targeting approach and expands the possibilities of cell-specific imaging and pharmacology.

Sign in / Sign up

Export Citation Format

Share Document