<meta charset="utf8"></head><body>从最小组织中高效分离脑 sEVs 以发现生物标志物

<ol>
	<li>Jia, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+extracellular+vesicles+isolation+and+separation:+Current+techniques,+pending+questions+and+clinical+applications.">Small extracellular vesicles isolation and separation: Current techniques, pending questions and clinical applications.</a> Theranostics. 12 (15), 6548-6575 (2022).</li><li>Fornari, S., Sch&#228;fer, A., Jucker, M., Goriely, A., Kuhl, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prion-like+spreading+of+Alzheimer's+disease+within+the+brain's+connectome.">Prion-like spreading of Alzheimer's disease within the brain's connectome.</a> J R Soc Interface. 16 (159), 20190356 (2019).</li><li>Zhang, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor-derived+small+extracellular+vesicles+in+cancer+invasion+and+metastasis:+molecular+mechanisms,+and+clinical+significance.">Tumor-derived small extracellular vesicles in cancer invasion and metastasis: molecular mechanisms, and clinical significance.</a> Mol Cancer. 23 (1), 18 (2024).</li><li>Constantinides, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CSF+A&#946;42+and+A&#946;42/+A&#946;40+ratio+in+Alzheimer's+disease+and+frontotemporal+dementia.">CSF A&#946;42 and A&#946;42/ A&#946;40 ratio in Alzheimer's disease and frontotemporal dementia.</a> Diagnostics. 13 (4), 783 (2023).</li><li>Cheng, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prognostic+serum+miRNA+biomarkers+associated+with+Alzheimer's+disease+shows+concordance+with+neuropsychological+and+neuroimaging+assessment.">Prognostic serum miRNA biomarkers associated with Alzheimer's disease shows concordance with neuropsychological and neuroimaging assessment.</a> Mol Psychiatry. 20 (10), 1188-1196 (2015).</li><li>Roser, A. E., Caldi Gomes, L., Sch&#252;nemann, J., Maass, F., Lingor, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Circulating+miRNAs+as+diagnostic+biomarkers+for+Parkinson's+disease.">Circulating miRNAs as diagnostic biomarkers for Parkinson's disease.</a> Front Neurosci. 12, 625 (2018).</li><li>Jackson, N., Guerrero-Mu&#241;oz, M. J., Castillo-Carranza, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+prion-like+transmission+of+tau+oligomers+via+exosomes.">The prion-like transmission of tau oligomers via exosomes.</a> Front Aging Neurosci. 14, 974414 (2022).</li><li>Vella, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+rigorous+method+to+enrich+for+exosomes+from+brain+tissue.">A rigorous method to enrich for exosomes from brain tissue.</a> J Extracell Vesicles. 6 (1), 1348885 (2017).</li><li>Yousif, G., Qadri, S., Parray, A., Akhthar, N., Shuaib, A., Haik, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exosomes+derived+neuronal+markers:+Immunoaffinity+isolation+and+characterization.">Exosomes derived neuronal markers: Immunoaffinity isolation and characterization.</a> Neuromolecular Med. 24 (3), 339-351 (2022).</li><li>Kumar, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+microfluidic+approaches+for+the+isolation+and+detection+of+exosomes.">Recent advances in microfluidic approaches for the isolation and detection of exosomes.</a> TRAC-Trend Anal Chem. 159, 116912 (2023).</li><li>Ransom, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+brain+small+extracellular+vesicles+contain+selectively+packaged,+full-length+mRNA.">Human brain small extracellular vesicles contain selectively packaged, full-length mRNA.</a> Cell Rep. 43 (4), 114061 (2024).</li><li>Gomes, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+isolation+method+for+spontaneously+released+extracellular+vesicles+from+brain+tissue+and+its+implication+for+stress-driven+brain+pathology.">A novel isolation method for spontaneously released extracellular vesicles from brain tissue and its implication for stress-driven brain pathology.</a> Cell Commun Signal. 21 (1), 35 (2023).</li><li>Welsh, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimal+information+for+studies+of+extracellular+vesicles+(MISEV+2023):+From+basic+to+advanced+approaches.">Minimal information for studies of extracellular vesicles (MISEV 2023): From basic to advanced approaches.</a> J Extracell Vesicles. 13 (2), e12404 (2023).</li><li>Th&#233;ry, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimal+information+for+studies+of+extracellular+vesicles+2018+(MISEV2018):+a+position+statement+of+the+International+Society+for+Extracellular+Vesicles+and+update+of+the+MISEV2014+guidelines.">Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines.</a> J Extracell Vesicles. 7 (1), 1535750 (2018).</li><li>Pirisinu, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+long+journey+of+extracellular+vesicles+towards+global+scientific+acclamation.">The long journey of extracellular vesicles towards global scientific acclamation.</a> Adv Pharm Bull. 13 (3), 489-501 (2023).</li><li>Bender, A., Sullivan, B. P., Lillis, L., Posner, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzymatic+and+chemical-based+methods+to+inactivate+endogenous+blood+ribonucleases+for+nucleic+acid+diagnostics.">Enzymatic and chemical-based methods to inactivate endogenous blood ribonucleases for nucleic acid diagnostics.</a> J Mol Diagn. 22 (8), 1030-1040 (2020).</li></ol>

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Bovine Serum Albumin</td>
			<td>Merck</td>
			<td>A9418-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Mask Orange Plasma Membrane Stain</td>
			<td>ThermoFisher Scientific</td>
			<td>C10045</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase Type-III</td>
			<td>StemCell Technologies</td>
			<td>07422</td>
			<td></td>
		</tr>
		<tr>
			<td>ExoSpin Columns and Buffer</td>
			<td>Cell Guidance Systems Ltd.</td>
			<td>EX01-50</td>
			<td>This kit contains SEC columns used in this experiment, precipitation buffer and EV free PBS.</td>
		</tr>
		<tr>
			<td>Halt Protease Inhibitor Cocktail (100x)</td>
			<td>ThermoFisher Scientific</td>
			<td>78429</td>
			<td></td>
		</tr>
		<tr>
			<td>Hibernate-E Medium</td>
			<td>ThermoFisher Scientific</td>
			<td>A1247601</td>
			<td></td>
		</tr>
		<tr>
			<td>Laemmli Sample Buffer (4x)</td>
			<td>BioRad</td>
			<td>1610747</td>
			<td></td>
		</tr>
		<tr>
			<td>Lexogen Small RNA-Seq Library Prep Kit</td>
			<td>Lexogen</td>
			<td>052.24</td>
			<td>This kit contains Small RNA preparation reagent box with i7 Index primer plate.&#160;</td>
		</tr>
		<tr>
			<td>miRNeasy Micro Kit (50)</td>
			<td>Qiagen</td>
			<td>217084</td>
			<td>This kit contains high-quality RNA recovery lysis reagent (Qiazol), RNA isolation columns, isolation buffers (RWT, RPE) and RNase free water.</td>
		</tr>
		<tr>
			<td>MiSeq Reagent Kit v3</td>
			<td>Illumina</td>
			<td>MS-102-3001</td>
			<td>This is the Illumina Preparation Kit</td>
		</tr>
		<tr>
			<td>Nitrocellulose Membrane, 0.45 &#956;m</td>
			<td>ThermoFisher Scientific</td>
			<td>88018</td>
			<td></td>
		</tr>
		<tr>
			<td>PE/Dazzle 594 anti-human CD63 Antibody</td>
			<td>BioLegend</td>
			<td>143914</td>
			<td>Used for fNTA Analysis</td>
		</tr>
		<tr>
			<td>PE/Dazzle 594 anti-human CD81 Antibody</td>
			<td>BioLegend</td>
			<td>349520</td>
			<td>Used for fNTA Analysis</td>
		</tr>
		<tr>
			<td>PE/Dazzle 594 anti-human CD9 Antibody</td>
			<td>BioLegend</td>
			<td>312118</td>
			<td>Used for fNTA Analysis</td>
		</tr>
		<tr>
			<td>PhosSTOP</td>
			<td>Merck</td>
			<td>4906845001</td>
			<td></td>
		</tr>
		<tr>
			<td>Pierce BCA Protein Assay Kit</td>
			<td>ThermoFisher Scientific</td>
			<td>23225</td>
			<td></td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>ThermoFisher Scientific</td>
			<td>25530049</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit microRNA Assay Kit</td>
			<td>ThermoFisher Scientific</td>
			<td>Q32880</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit 1X dsDNA HS assay kit</td>
			<td>ThermoFisher Scientific</td>
			<td>Q33230</td>
			<td></td>
		</tr>
		<tr>
			<td>Qubit 3.0 Fluorometer</td>
			<td>ThermoFisher Scientific</td>
			<td>Q33216</td>
			<td></td>
		</tr>
		<tr>
			<td>RIPA Lysis and Extraction Buffer</td>
			<td>ThermoFisher Scientific</td>
			<td>89901</td>
			<td></td>
		</tr>
		<tr>
			<td>RNase A</td>
			<td>ThermoFisher Scientific</td>
			<td>EN0531</td>
			<td></td>
		</tr>
		<tr>
			<td>SuperSignal West Femto Maximum Sensitivity Substrate</td>
			<td>ThermoFisher Scientific</td>
			<td>34094</td>
			<td></td>
		</tr>
	</tbody>
</table>

harnessing the power of microrna cargoes in small extracellular vesicles released from fresh-frozen human brain sections 

<meta charset="utf8"></head><body>利用 MicroRNA 货物在新鲜冷冻人脑切片释放的小细胞外囊泡中的力量

利用 MicroRNA 货物在新鲜冷冻人脑切片释放的小细胞外囊泡中的力量 

Small extracellular vesicles (sEVs) are crucial mediators of cell-cell communication, transporting diverse cargoes like proteins, lipids, and nucleic ...

harnessing-power-microrna-cargoes-small-extracellular-vesicles

Research

JoVE Journal

Neuroscience

Harnessing the Power of MicroRNA Cargoes in Small Extracellular Vesicles Released from Fresh-Frozen Human Brain Sections 

307 次观看.  University of Salford. 在这里，我们使用最少量的新鲜冷冻脑组织切片和可访问的高速离心方法结合尺寸排阻色谱法建立了一个方案，以获得小的细胞外囊泡作为神经系统疾病的 microRNA （miRNA） 生物标志物的来源。 

视频: 利用 MicroRNA 货物在新鲜冷冻人脑切片释放的小细胞外囊泡中的力量

Double Fluorescence in situ Hybridization in Fresh Brain Sections

Here we describe a modified version of a double fluorescence in situ hybridization (dFISH) method optimized for detecting two mRNAs of interest in fresh frozen brain sections. Our group has successfully used this approach to study gene co-regulation. More specifically, we have used this dFISH method to explore the anatomical organization, neurochemical properties, and the impact of sensory experience in central sensory circuits, at single cell resolution. This protocol has been validated in brain tissue from mice, rats and songbirds but is expected to be easily adaptable to other vertebrate species, as well as to an array of non-neural tissues. In this film we provide a detailed demonstration of the main steps of this procedure.

Double Fluorescence in situ Hybridization in Fresh Brain Sections

This protocol involves a non-radioactive in-situ hybridization procedure that enables the simultaneous identification of two transcript species, at a single cell resolution, in thin sections of the vertebrate brain.

双荧光原位杂交食脑切片

Here we describe a modified version of a double fluorescence in situ hybridization (dFISH) method optimized for detecting two mRNAs of interest in fresh ...

科研

神经科学

Efficient Derivation of Human Neuronal Progenitors and Neurons from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system (CNS) structure and circuitry in today's healthcare industry. Cell-based therapies hold great promise to restore the lost nerve tissue and function for CNS disorders. However, cell therapies based on CNS-derived neural stem cells have encountered supply restriction and difficulty to use in the clinical setting due to their limited expansion ability in culture and failing plasticity after extensive passaging1-3. Despite some beneficial outcomes, the CNS-derived human neural stem cells (hNSCs) appear to exert their therapeutic effects primarily by their non-neuronal progenies through producing trophic and neuroprotective molecules to rescue the endogenous cells1-3. Alternatively, pluripotent human embryonic stem cells (hESCs) proffer cures for a wide range of neurological disorders by supplying the diversity of human neuronal cell types in the developing CNS for regeneration1,4-7. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity7-10. In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic11-13. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules14 (please see a schematic in Fig. 1). Retinoic acid (RA) does not induce neuronal differentiation of undifferentiated hESCs maintained on feeders1, 14. And unlike mouse ESCs, treating hESC-differentiated embryoid bodies (EBs) only slightly increases the low yield of neurons1, 14, 15. However, after screening a variety of small molecules and growth factors, we found that such defined conditions rendered retinoic acid (RA) sufficient to induce the specification of neuroectoderm direct from pluripotent hESCs that further progressed to neuroblasts that generated human neuronal progenitors and neurons in the developing CNS with high efficiency (Fig. 2). We defined conditions for induction of neuroblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human neuronal cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of neuroblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human neuronal progenitors and neuronal cell types in the developing CNS for neural repair.

人类神经祖细胞和神经元小分子诱导人类胚胎干细胞的多能干高效的推导

There is a large unfulfilled need for a clinically-suitable human neuronal cell source for repair or regeneration of the damaged central nervous system ...

Morphometric Analyses of Retinal Sections

Morphometric analyses of retinal sections have been used in examining retinal diseases. For examples, neuronal cells were significantly lost in the retinal ganglion cell layer (RGCL) in rat models with N-methyl-D-aspartate (NMDA)&#x2013;induced excitotoxicity1, retinal ischemia-reperfusion injury2 and glaucoma3. Reduction of INL and inner plexiform layer (IPL) thicknesses were reversed with citicoline treatment in rats' eyes subjected to kainic acid-mediated glutamate excitotoxicity4. Alteration of RGC density and soma sizes were observed with different drug treatments in eyes with elevated intraocular pressure3,5,6. Therefore, having objective methods of analyzing the retinal morphometries may be of great significance in evaluating retinal pathologies and the effectiveness of therapeutic strategies.
The retinal structure is multi-layers and several different kinds of neurons exist in the retina. The morphometric parameters of retina such as cell number, cell size and thickness of different layers are more complex than the cell culture system. Early on, these parameters can be detected using other commercial imaging software. The values are normally of relative value, and changing to the precise value may need further accurate calculation. Also, the tracing of the cell size and morphology may not be accurate and sensitive enough for statistic analysis, especially in the chronic glaucoma model. The measurements used in this protocol provided a more precise and easy way. And the absolute length of the line and size of the cell can be reported directly and easy to be copied to other files. For example, we traced the margin of the inner and outer most nuclei in the INL and formed a line then using the software to draw a 90 degree angle to measure the thickness. While without the help of the software, the line maybe oblique and the changing of retinal thickness may not be repeatable among individual observers. In addition, the number and density of RGCs can also be quantified. This protocol successfully decreases the variability in quantitating features of the retina, increases the sensitivity in detecting minimal changes.
 	This video will demonstrate three types of morphometric analyses of the retinal sections. They include measuring the INL thickness, quantifying the number of RGCs and measuring the sizes of RGCs in absolute value. These three analyses are carried out with Stereo Investigator (MBF Bioscience &mdash; MicroBrightField, Inc.). The technique can offer a simple but scientific platform for morphometric analyses.

This video demonstrates three types of morphometric analyses of the retina, which include measuring the inner nuclear layer thickness, quantifying the number of retinal ganglion cells (RGCs) and measuring the sizes of RGCs. The technique can offer a simple but scientific platform for morphometric analyses.

视网膜节的形态分析

Morphometric analyses of retinal sections have been used in examining retinal diseases. For examples, neuronal cells were significantly lost in the ...

Design and Assembly of an Ultra-light Motorized Microdrive for Chronic Neural Recordings in Small Animals

The ability to chronically record from populations of neurons in freely behaving animals has proven an invaluable tool for dissecting the function of neural circuits underlying a variety of natural behaviors, including navigation1 , decision making 2,3, and the generation of complex motor sequences4,5,6. Advances in precision machining has allowed for the fabrication of light-weight devices suitable for chronic recordings in small animals, such as mice and songbirds. The ability to adjust the electrode position with small remotely controlled motors has further increased the recording yield in various behavioral contexts by reducing animal handling.6,7
 Here we describe a protocol to build an ultra-light motorized microdrive for long-term chronic recordings in small animals. Our design evolved from an earlier published version7, and has been adapted for ease-of use and cost-effectiveness to be more practical and accessible to a wide array of researchers. This proven design 8,9,10,11 allows for fine, remote positioning of electrodes over a range of ~ 5 mm and weighs less than 750 mg when fully assembled. We present the complete protocol for how to build and assemble these drives, including 3D CAD drawings for all custom microdrive components.

The design, fabrication and assembly of an ultra-light motorized microdrive is described. The device provides a cost-effective and easy-to-use solution for chronic recordings of single units in small behaving animals.

设计和组装的超轻型电动微型硬盘（Microdrive）慢性神经录音的小动物

The ability to chronically record from populations of neurons in freely behaving animals has proven an invaluable tool for dissecting the function of ...

Recording Synaptic Plasticity in Acute Hippocampal Slices Maintained in a Small-volume Recycling-, Perfusion-, and Submersion-type Chamber System

Even though experiments on brain slices have been in use since 1951, problems remain that reduce the probability of achieving a stable and successful analysis of synaptic transmission modulation when performing field potential or intracellular recordings. This manuscript describes methodological aspects that might be helpful in improving experimental conditions for the maintenance of acute brain slices and for recording field excitatory postsynaptic potentials in a commercially available submersion chamber with an outflow-carbogenation unit. The outflow-carbogenation helps to stabilize the oxygen level in experiments that rely on the recycling of a small buffer reservoir to enhance the cost-efficiency of drug experiments. In addition, the manuscript presents representative experiments that examine the effects of different carbogenation modes and stimulation paradigms on the activity-dependent synaptic plasticity of synaptic transmission.

This protocol describes the stabilization of the oxygen level in a small volume of recycled buffer and methodological aspects of recording activity-dependent synaptic plasticity in submerged acute hippocampal slices.

小容积回收-灌注-浸没式室系统中维持的急性海马切片的突触可塑性记录

Even though experiments on brain slices have been in use since 1951, problems remain that reduce the probability of achieving a stable and successful ...

Optimization of Laser-Capture Microdissection for the Isolation of Enteric Ganglia from Fresh-Frozen Human Tissue

The purpose of this method is to obtain high-integrity RNA samples from enteric ganglia collected from unfixed, freshly-resected human intestinal tissue using laser capture microdissection (LCM). We have identified five steps in the workflow that are crucial for obtaining RNA isolates from enteric ganglia with sufficiently high quality and quantity for RNA-seq. First, when preparing intestinal tissue, each sample must have all excess liquid removed by blotting prior to flattening the serosa as much as possible across the bottom of large base molds. Samples are then quickly frozen atop a slurry of dry ice and 2-methylbutane. Second, when sectioning the tissue, it is important to position cryomolds so that intestinal sections parallel the full plane of the myenteric plexus, thereby yielding the greatest surface area of enteric ganglia per slide. Third, during LCM, polyethylene napthalate (PEN)-membrane slides offer the greatest speed and flexibility in outlining the non-uniform shapes of enteric ganglia when collecting enteric ganglia. Fourth, for distinct visualization of enteric ganglia within sections, ethanol-compatible dyes, like Cresyl Violet, offer excellent preservation of RNA integrity relative to aqueous dyes. Finally, for the extraction of RNA from captured ganglia, we observed differences between commercial RNA extraction kits that yielded superior RNA quantity and quality, while eliminating DNA contamination. Optimization of these factors in the current protocol greatly accelerates the workflow and yields enteric ganglia samples with exceptional RNA quality and quantity.

The goal of this protocol is to obtain high-integrity RNA samples from enteric ganglia isolated from unfixed, freshly-resected human intestinal tissue using laser capture microdissection (LCM). This protocol involves preparing flash-frozen samples of human intestinal tissue, cryosectioning, ethanolic staining and dehydration, LCM, and RNA extraction.

激光捕获显微切割分离新鲜冷冻人体肠神经节的优化

The purpose of this method is to obtain high-integrity RNA samples from enteric ganglia collected from unfixed, freshly-resected human intestinal tissue ...

The Power of Interstimulus Interval for the Assessment of Temporal Processing in Rodents

Temporal processing deficits have been implicated as a potential elemental dimension of higher-level cognitive processes, commonly observed in neurocognitive disorders. Despite the popularization of prepulse inhibition (PPI) in recent years, many current protocols promote using a percent of control measure, thereby precluding the assessment of temporal processing. The present study used cross-modal PPI and gap prepulse inhibition (gap-PPI) to demonstrate the benefits of employing a range of interstimulus intervals (ISIs) to delineate effects of sensory modality, psychostimulant exposure, and age. Assessment of sensory modality, psychostimulant exposure, and age reveals the utility of an approach varying the interstimulus interval (ISI) to establish the shape of the ISI function, including increases (sharper curve inflections) or decreases (flattening of the response amplitude curve) in startle amplitude. Additionally, shifts in peak response inhibition, suggestive of a differential sensitivity to the manipulation of ISI, are often revealed. Thus, the systematic manipulation of ISI affords a critical opportunity to evaluate temporal processing, which may reveal the underlying neural mechanisms involved in neurocognitive disorders.

Temporal processing, a preattentive process, may underlie deficits in higher-level cognitive processes, including attention, commonly observed in neurocognitive disorders. Using prepulse inhibition as an exemplar paradigm, we present a protocol for manipulating interstimulus interval (ISI) to establish the shape of the ISI function to provide an assessment of temporal processing.

间刺激间隔对啮齿类动物时间处理评估的力量

Temporal processing deficits have been implicated as a potential elemental dimension of higher-level cognitive processes, commonly observed in ...

Combining Multiplex Fluorescence In Situ Hybridization with Fluorescent Immunohistochemistry on Fresh Frozen or Fixed Mouse Brain Sections

Fluorescent in situ hybridization (FISH) is a molecular technique that identifies the presence and spatial distribution of specific RNA transcripts within cells. Neurochemical phenotyping of functionally identified neurons usually requires concurrent labelling with multiple antibodies (targeting protein) using immunohistochemistry (IHC) and optimization of in situ hybridization (targeting RNA), in tandem. A &#34;neurochemical signature&#34; to characterize particular neurons may be achieved however complicating factors include the need to verify FISH and IHC targets before combining the methods, and the limited number of RNAs and proteins that may be targeted simultaneously within the same tissue section.
Here we describe a protocol, using both fresh frozen and fixed mouse brain preparations, which detects multiple mRNAs and proteins in the same brain section using RNAscope FISH followed by fluorescence immunostaining, respectively. We use the combined method to describe the expression pattern of low abundance mRNAs (e.g., galanin receptor 1) and high abundance mRNAs (e.g., glycine transporter 2), in immunohistochemically identified brainstem nuclei.
Key considerations for protein labelling downstream of the FISH assay extend beyond tissue preparation and optimization of FISH probe labelling. For example, we found that antibody binding and labelling specificity can be detrimentally affected by the protease step within the FISH probe assay. Proteases catalyze hydrolytic cleavage of peptide bonds, facilitating FISH probe entry into cells, however they may also digest the protein targeted by the subsequent IHC assay, producing off target binding. The subcellular location of the targeted protein is another factor contributing to IHC success following FISH probe assay. We observed IHC specificity to be retained when the targeted protein is membrane bound, whereas IHC targeting cytoplasmic protein required extensive troubleshooting. Finally, we found handling of slide-mounted fixed frozen tissue more challenging than fresh frozen tissue, however IHC quality was overall better with fixed frozen tissue, when combined with RNAscope.

Combining Multiplex Fluorescence In Situ Hybridization with Fluorescent Immunohistochemistry on Fresh Frozen or Fixed Mouse Brain Sections

This protocol describes a method for combining fluorescence in situ hybridization (FISH) and fluorescence immunohistochemistry (IHC) in both fresh frozen and fixed mouse brain sections, with the goal of achieving multilabel FISH and fluorescence IHC signal. IHC targeted cytoplasmic and membrane attached proteins.

将多重荧光 原 位杂交与荧光免疫组化相结合，对新鲜冷冻或固定的小鼠脑切片进行研究

Fluorescent in situ hybridization (FISH) is a molecular technique that identifies the presence and spatial distribution of specific RNA transcripts within ...

Isolation of Adult Human Astrocyte Populations from Fresh-Frozen Cortex Using Fluorescence-Activated Nuclei Sorting

The complexity of human astrocytes remains poorly defined in primary human tissue, requiring better tools for their isolation and molecular characterization. Fluorescence-activated nuclei sorting (FANS) can be used to successfully isolate and study human neuronal nuclei (NeuN+) populations from frozen archival tissue, thereby avoiding problems associated with handling&#160;fresh tissue. However, efforts to similarly isolate astroglia from the non-neuronal (NeuN-) element are lacking. A recently developed and validated immunotagging strategy uses three transcription factor antibodies to simultaneously isolate enriched neuronal (NeuN+), astrocyte (paired box protein 6 (PAX6)+NeuN-), and oligodendrocyte progenitor (OLIG2+NeuN-) nuclei populations from non-diseased, fresh (unfixed) snap-frozen&#160;postmortem human temporal neocortex tissue.
This technique was shown to be useful for the characterization of cell type-specific transcriptome alterations in primary pathological epilepsy neocortex. Transcriptomic analyses confirmed that PAX6+NeuN- sorted populations are robustly enriched for pan-astrocyte markers and capture astrocytes in both resting and reactive conditions. This paper describes the FANS methodology for the isolation of astrocyte-enriched nuclei populations from fresh-frozen human cortex, including tissue dissociation into single-nucleus (sn) suspension; immunotagging of nuclei with anti-NeuN and anti-PAX6 fluorescently conjugated antibodies; FANS gating strategies and quality control metrics for optimizing sensitivity and specificity during sorting and for confirming astrocyte enrichment; and recommended procurement for downstream transcriptome and chromatin accessibility sequencing at bulk or sn resolution. This protocol is applicable for non-necrotic, fresh-frozen, human cortical specimens with various pathologies and recommended postmortem tissue collection within 24 h.

We have developed a method that enriches for and isolates human astrocyte populations from fresh-frozen tissue for use in downstream molecular analyses.

使用荧光激活的细胞核分选从新鲜冷冻的皮质中分离出成年人类星形胶质细胞群

The complexity of human astrocytes remains poorly defined in primary human tissue, requiring better tools for their isolation and molecular ...

Uptake of Fluorescent Labeled Small Extracellular Vesicles In Vitro and in Spinal Cord

Small extracellular vesicles (sEVs) are 50-150 nm vesicles secreted by all cells and present in bodily fluids. sEVs transfer biomolecules such as RNA, proteins, and lipids from donor to acceptor cells, making them key signaling mediators between cells. In the central nervous system (CNS), sEVs can mediate intercellular signaling, including neuroimmune interactions. sEV functions can be studied by tracking the uptake of labeled sEVs in recipient cells both in vitro and in vivo. This paper describes the labeling of sEVs from the conditioned media of RAW 264.7 macrophage cells using a PKH membrane dye. It shows the uptake of different concentrations of labeled sEVs at multiple time points by Neuro-2a cells and primary astrocytes in vitro. Also shown is the uptake of sEVs delivered intrathecally in mouse spinal cord neurons, astrocytes, and microglia visualized by confocal microscopy. The representative results demonstrate time-dependent variation in the uptake of sEVs by different cells, which can help confirm successful sEVs delivery into the spinal cord.

Uptake of Fluorescent Labeled Small Extracellular Vesicles In Vitro and in Spinal Cord

We describe a protocol to label macrophage-derived small extracellular vesicles with PKH dyes and observe their uptake in vitro and in the spinal cord after intrathecal delivery.

吸收荧光标记的小细胞外囊泡 在体外 和脊髓

Small extracellular vesicles (sEVs) are 50-150 nm vesicles secreted by all cells and present in bodily fluids. sEVs transfer biomolecules such as RNA, ...