Dr. Cruz-Orengo was supported by the University of California, Davis, School of Veterinary Medicine Start Up Funds.

All procedures of the present study are in accordance with the guidelines set by the University of California (UC), Davis Institutional Animal Care and Use Committee (IACUC). Animal care at UC Davis is regulated by several independent resources and has been fully accredited by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC) since 1966. Porcine CNS tissues were obtained from UCD Department of Animal Sciences, Meat Sciences Laboratory. CNS tissues from rhesus macaques were ...

<ol>
	<li>Bundgaard, M., Abbott, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=All+vertebrates+started+out+with+a+glial+blood-brain+barrier+4-500+million+years+ago.">All vertebrates started out with a glial blood-brain barrier 4-500 million years ago.</a> Glia. 56, 699-708 (2008).</li><li>Daneman, R., Prat, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+blood-brain+barrier.">The blood-brain barrier.</a> Cold Spring Harbor Perspectives in Biology. 7, a020412 (2015).</li><li>Obermeier, B., Verma, A., Ransohoff, R. 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+blood-brain+barrier.">The blood-brain barrier.</a> Handbook of Clinical Neurology. 133, 39-59 (2016).</li><li>Kealy, J., Greene, C., Campbell, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier+regulation+in+psychiatric+disorders.">Blood-brain barrier regulation in psychiatric disorders.</a> Neuroscience Letters. , (2018).</li><li>Sweeney, M. D., Kisler, K., Montagne, A., Toga, A. W., Zlokovic, B. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+brain+vasculature+in+neurodegenerative+disorders.">The role of brain vasculature in neurodegenerative disorders.</a> Nature Neuroscience. 21, 1318-1331 (2018).</li><li>Sweeney, M. D., Zhao, Z., Montagne, A., Nelson, A. R., Zlokovic, B. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-Brain+Barrier:+From+Physiology+to+Disease+and+Back.">Blood-Brain Barrier: From Physiology to Disease and Back.</a> Physiological Reviews. 99, 21-78 (2019).</li><li>Wilhelm, I., Nyul-Toth, A., Suciu, M., Hermenean, A., Krizbai, I. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterogeneity+of+the+blood-brain+barrier.">Heterogeneity of the blood-brain barrier.</a> Tissue Barriers. 4, e1143544 (2016).</li><li>O'Brown, N. M., Pfau, S. 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R., Franke, M. C., Yuan, Y., Cruz-Orengo, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Straightforward+method+for+singularized+and+region-specific+CNS+microvessels+isolation.">Straightforward method for singularized and region-specific CNS microvessels isolation.</a> Journal of Neuroscience Methods. 318, 17-33 (2019).</li><li>Smyth, L. C. D., 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=Markers+for+human+brain+pericytes+and+smooth+muscle+cells.">Markers for human brain pericytes and smooth muscle cells.</a> Journal of Chemical Neuroanatomy. 92, 48-60 (2018).</li><li>Granberg, T., 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=In+vivo+characterization+of+cortical+and+white+matter+neuroaxonal+pathology+in+early+multiple+sclerosis.">In vivo characterization of cortical and white matter neuroaxonal pathology in early multiple sclerosis.</a> Brain. 140, 2912-2926 (2017).</li><li>Datta, G., 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=Neuroinflammation+and+its+relationship+to+changes+in+brain+volume+and+white+matter+lesions+in+multiple+sclerosis.">Neuroinflammation and its relationship to changes in brain volume and white matter lesions in multiple sclerosis.</a> Brain. 140, 2927-2938 (2017).</li><li>Tommasin, S., Gianni, C., De Giglio, L., Pantano, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroimaging+Techniques+to+Assess+Inflammation+in+Multiple+Sclerosis.">Neuroimaging Techniques to Assess Inflammation in Multiple Sclerosis.</a> Neuroscience. 403, 4-16 (2019).</li><li>Liebner, S., 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=Functional+morphology+of+the+blood-brain+barrier+in+health+and+disease.">Functional morphology of the blood-brain barrier in health and disease.</a> Acta Neuropathologica. 135, 311-336 (2018).</li><li>Cornford, E., Hyman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localization+of+brain+endothelial+luminal+and+abluminal+transporters+with+immunogold+electron+microscopy.">Localization of brain endothelial luminal and abluminal transporters with immunogold electron microscopy.</a> NeuroRx. 2, 27-43 (2005).</li><li>Boulay, A. C., Saubamea, B., Decleves, X., Cohen-Salmon, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purification+of+Mouse+Brain+Vessels.">Purification of Mouse Brain Vessels.</a> Journal of Visualized Experiments. , 53208 (2015).</li><li>Paul, D., Cowan, A. E., Ge, S., Pachter, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+3D+analysis+of+Claudin-5+reveals+significant+endothelial+heterogeneity+among+CNS+microvessels.">Novel 3D analysis of Claudin-5 reveals significant endothelial heterogeneity among CNS microvessels.</a> Microvascular Research. , (2012).</li><li>Munikoti, V. V., Hoang-Minh, L. B., Ormerod, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enzymatic+digestion+improves+the+purity+of+harvested+cerebral+microvessels.">Enzymatic digestion improves the purity of harvested cerebral microvessels.</a> Journal of Neuroscience Methods. 207, 80-85 (2012).</li><li>Yousif, S., Marie-Claire, C., Roux, F., Scherrmann, J. M., Decleves, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+drug+transporters+at+the+blood-brain+barrier+using+an+optimized+isolated+rat+brain+microvessel+strategy.">Expression of drug transporters at the blood-brain barrier using an optimized isolated rat brain microvessel strategy.</a> Brain Research. 1134, 1-11 (2007).</li><li>Bourassa, P., Tremblay, C., Schneider, J. A., Bennett, D. A., Calon, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta-amyloid+pathology+in+human+brain+microvessel+extracts+from+the+parietal+cortex:+relation+with+cerebral+amyloid+angiopathy+and+Alzheimer's+disease.">Beta-amyloid pathology in human brain microvessel extracts from the parietal cortex: relation with cerebral amyloid angiopathy and Alzheimer's disease.</a> Acta Neuropathologica. 137, 801-823 (2019).</li><li>Porte, B., 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=Proteomic+and+transcriptomic+study+of+brain+microvessels+in+neonatal+and+adult+mice.">Proteomic and transcriptomic study of brain microvessels in neonatal and adult mice.</a> PLoS One. 12, e0171048 (2017).</li></ol>

The authors have nothing to disclose.

The BBB includes the unique properties of the brain microvasculature endothelial cells coupled by a sophisticated architecture of tight-, adherens-, &#34;peg-socket&#34;- junctions, and adhesion plaques critical for CNS homeostasis2,3,19. Endothelial cells properties are induced and maintained by pericytes and the surrounding astroglia end-foot processes2,3,<s...

Our brain is the most important organ in our body. For this reason, keeping brain homeostasis despite external factors that may trigger a deviation from normalcy is a priority. According to some scholars, about 400&#8211;500 million years ago1, vertebrate animals developed what we now know as the blood-brain barrier (BBB)2,3. This protective &#34;fence&#34; exerts the greatest influence over central nervous system (CNS) homeostasis and functions by tightly regulating the transport of ions, molecules, and cells between blood and CNS parenchyma. When the BBB is disrupted, the brain becomes susceptible to toxic exposure, infection, and inflammation. Therefore, BBB dysfunction is associated with many, if not all, neurological and neurodevelopmental disorders4,5,6.
The sophisticated function of the BBB is attributed to the unique CNS microvasculature conformed by the neurovascular unit (NVU)2,3. Highly specialized endothelial cells, pericytes, and astrocytic end-feet are the cellular components of the NVU2,3. The extracellular matrix generated by these cells is also essential to the NVU and BBB physiology2,3. Although essential cellular and molecular components of the NVU are conserved among vertebrates, heterogeneity is reported among orders and species7,8. However, technical limitations impede our ability to fully consider these differences in neurobiology, biomedical, or translational research.
Because of this, we expanded a CNS region-specific microvessel-isolation method to make it applicable to numerous species from all five vertebrate groups: fish, amphibians, reptiles, birds, and mammals. The protocol is described for use on small-lissencephalic and large-gyrencephalic vertebrates, including species with translational relevance9. Additionally, we include other regions of the CNS not investigated before within this context, but relevant to neurophysiology and with tremendous clinical implications: the hypothalamus, pituitary, and white matter. Lastly, we tested the capacity of this isolation method as a reliable tool to identify changes in protein expression along the NVU and/or BBB9,10,11. As a proof-of-concept, we showed how to determine changes in VCAM-1 and JAM-B expression during EAE using the isolation method followed by immunofluorescence.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>10X PBS</td>
			<td>ThermoFisher</td>
			<td>BP39920</td>
			<td>Used for blocking and antibody diluent.</td>
		</tr>
		<tr>
			<td>20% PFA</td>
			<td>Electron Microscopy Sciences</td>
			<td>15713-S</td>
			<td>Used as fixative (4% PFA)</td>
		</tr>
		<tr>
			<td>70,000 MW Dextran</td>
			<td>Millipore Sigma</td>
			<td>9004-54-0</td>
			<td>Used for MV-2 solution</td>
		</tr>
		<tr>
			<td>Adson Forceps</td>
			<td>Fine Science Tools (FST)</td>
			<td>11006-12</td>
			<td>Used for removal of muscle and skin</td>
		</tr>
		<tr>
			<td>Adson Forceps, student quality</td>
			<td>FST</td>
			<td>91106-12</td>
			<td>Same as above but cheaper</td>
		</tr>
		<tr>
			<td>Bovine serum albumin (BSA)</td>
			<td>Millipore Sigma</td>
			<td>A7906-100G</td>
			<td>Used for MV-3 solution, blocking and antibody diluent</td>
		</tr>
		<tr>
			<td>Corning 100 &#956;m Cell strainer</td>
			<td>Millipore Sigma</td>
			<td>CLS431752-50EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning 70 &#956;m Cell strainer</td>
			<td>Millipore Sigma</td>
			<td>CLS431751-50EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning Deskwork low-binding tips</td>
			<td>Millipore Sigma</td>
			<td>CLS4151</td>
			<td>Same as below but cheaper.</td>
		</tr>
		<tr>
			<td>Cultrex Poly-D-Lysine</td>
			<td>R&#38;D</td>
			<td>3439-100-01</td>
			<td>Used for slide coating</td>
		</tr>
		<tr>
			<td>Donkey anti-Goat IgG-ALEXA 555</td>
			<td>Thermo</td>
			<td>A21432</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Donkey anti-Mouse IgG-ALEXA 488</td>
			<td>Thermo</td>
			<td>A21202</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Donkey anti-Rabbit IgG-ALEXA 488</td>
			<td>Thermo</td>
			<td>A21206</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Donkey anti-Rabbit IgG-ALEXA 647</td>
			<td>Thermo</td>
			<td>A31573</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Donkey anti-Rat IgG-DyLight 650</td>
			<td>Thermo</td>
			<td>SA5-10029</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Double-Pronged Tissue Pick</td>
			<td>FST</td>
			<td>18067-11</td>
			<td>Used for removal of meninges and choroid plexus</td>
		</tr>
		<tr>
			<td>Dumont #3c Forceps</td>
			<td>FST</td>
			<td>11231-20</td>
			<td>Used for more delicate and/or small CNS tissue handling (like pituitary)</td>
		</tr>
		<tr>
			<td>Dumont #7 Forceps</td>
			<td>FST</td>
			<td>11274-20</td>
			<td>Used for CNS tisssue dissection and handling</td>
		</tr>
		<tr>
			<td>Dumont #7 Forceps, student</td>
			<td>FST</td>
			<td>91197-00</td>
			<td>Same as above but cheaper</td>
		</tr>
		<tr>
			<td>ep Dualfilter T.I.P.S. LoRetention Tips</td>
			<td>Eppendorf</td>
			<td>22493008</td>
			<td>Better quality than the tips above (more expensive).</td>
		</tr>
		<tr>
			<td>Extra Fine Graefe Forceps, serrated</td>
			<td>FST</td>
			<td>11151-10</td>
			<td>Used for bone removal</td>
		</tr>
		<tr>
			<td>Fine Scissors, sharp</td>
			<td>FST</td>
			<td>14060-09</td>
			<td>Used for removal of pig and macaque dural sac</td>
		</tr>
		<tr>
			<td>Glass Pestle 1.5 mL Microcentrifuge Tube Tissue Grinder Homogenizer, Pack of 10</td>
			<td>Chang Bioscience Inc. (eBay)</td>
			<td>GP1.5_10</td>
			<td>Used for small vetebrate hypothalus and pituitary.</td>
		</tr>
		<tr>
			<td>Goat anti-CXCL12, biotinylated</td>
			<td>PeproTech</td>
			<td>500-P87BGBT</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended dilution: 1:20.</td>
		</tr>
		<tr>
			<td>Goat anti-JAM-B</td>
			<td>R&#38;D</td>
			<td>AF1074</td>
			<td>Used as primary antibody to assess neuroinflammation. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Goat anti-Mouse IgG-ALEXA 488</td>
			<td>Thermo</td>
			<td>A11001</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Goat anti-Mouse IgG-ALEXA 555</td>
			<td>Thermo</td>
			<td>A21424</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Goat anti-PDGFR&#946;</td>
			<td>R&#38;D</td>
			<td>AF1042</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Goat anti-Rabbit IgG-ALEXA 555</td>
			<td>Thermo</td>
			<td>A21249</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Goat anti-Rabbit IgG-DyLight 488</td>
			<td>Thermo</td>
			<td>35552</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Goat anti-Rat IgG-DyLight 650</td>
			<td>Thermo</td>
			<td>SA5-10021</td>
			<td>Used as secondary antibody. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Graefe Forceps, curved tip, 1X2 teeth</td>
			<td>FST</td>
			<td>11054-10</td>
			<td>Use for nylon filter net holding and shaking</td>
		</tr>
		<tr>
			<td>HBSS, 1X buffer with calcium and magnesium</td>
			<td>Corning</td>
			<td>21-022-CM</td>
			<td>Used for MV-1 solution</td>
		</tr>
		<tr>
			<td>HEPES, 1M liquid buffer</td>
			<td>Corning</td>
			<td>25-060-CI</td>
			<td>Used for MV-1 solution</td>
		</tr>
		<tr>
			<td>Isolectin GS-IB4-Biotin-XX</td>
			<td>ThermoFisher Scientific (Thermo)</td>
			<td>I21414</td>
			<td>Glycoprotein isolated from legume Griffonia simplicifolia that binds D-galactosyl residues of endothelial cell glycocalysx. Used for avian and porcine CNS microvessels. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>LaGrange Scissors, serrated</td>
			<td>FST</td>
			<td>14173-12</td>
			<td>Used for skull dissection and laminectomy (except pig and macaque)</td>
		</tr>
		<tr>
			<td>Millicell EZ slide 8-well unit</td>
			<td>Millipore Sigma</td>
			<td>PEZGS0816</td>
			<td></td>
		</tr>
		<tr>
			<td>Mouse anti-CLDN5</td>
			<td>Thermo</td>
			<td>35-2500</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Mouse anti-GGT1</td>
			<td>Abcam</td>
			<td>ab55138</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Mouse anti-Human CD31</td>
			<td>R&#38;D</td>
			<td>BBA7</td>
			<td>Used as primary antibody on primate CNS microvessels. Recommended concentration: 16.5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Mouse anti-NFM</td>
			<td>Thermo</td>
			<td>RMO-270</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Mouse anti-&#945;SMA</td>
			<td>Thermo</td>
			<td>MA5-11547</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Nylon Filter Net, roll</td>
			<td>Millipore Sigma</td>
			<td>NY6000010</td>
			<td>Laser-cut to 13 mm diameter filter net discs. Used for small vetebrate hypothalus and pituitary.</td>
		</tr>
		<tr>
			<td>Nylon Filter Nets, 25 mm</td>
			<td>Millipore Sigma</td>
			<td>NY2002500</td>
			<td>Used on most small vertebrates CNS tissues, except hypothalamus and pituitary. Used for macaque and pig hypothalamus and pituitary.</td>
		</tr>
		<tr>
			<td>Nylon Filter Nets, 47 mm</td>
			<td>Millipore Sigma</td>
			<td>NY2004700</td>
			<td>Used for macaque and pig CNS tissues, except hypothalamus and pituitary.</td>
		</tr>
		<tr>
			<td>ProLong Gold antifade reagent with DAPI</td>
			<td>ThermoFisher</td>
			<td>P36935</td>
			<td>Used to coverslip slides.</td>
		</tr>
		<tr>
			<td>Rabbit anti-AQP4</td>
			<td>Millipore Sigma</td>
			<td>A5971</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Rabbit anti-LSR</td>
			<td>Millipore Sigma</td>
			<td>SAB2107967</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Rabbit anti-NG2</td>
			<td>Millipore Sigma</td>
			<td>AB5320</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Rabbit anti-OSP</td>
			<td>Abcam</td>
			<td>ab53041</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 1 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Rabbit anti-VE-Cadherin</td>
			<td>Abcam</td>
			<td>ab33168</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Rabbit anti-ZO-1</td>
			<td>Thermo</td>
			<td>61-7300</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Rat anti-CD31</td>
			<td>Becton Dickinson</td>
			<td>BD 550274</td>
			<td>Used as primary antibody for murine CNS microvessels. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Rat anti-GFAP</td>
			<td>Thermo</td>
			<td>13-0300</td>
			<td>Used as primary antibody on CNS microvessels from all specimens. Recommended dilution of 1:200.</td>
		</tr>
		<tr>
			<td>Rat anti-VCAM-1</td>
			<td>Becton Dickinson</td>
			<td>BD 553329</td>
			<td>Used as primary antibody to assess neuroinflammation. Recommended concentration: 5 &#956;g/mL.</td>
		</tr>
		<tr>
			<td>Sterile Ringer&#39;s Solution, Frog</td>
			<td>Aldon Corporation</td>
			<td>IS5066</td>
			<td>Used for amfibian anesthesia</td>
		</tr>
		<tr>
			<td>Streptavidin-ALEXA 555</td>
			<td>Thermo</td>
			<td>S32355</td>
			<td>Used as secondary antibody to label biotinylated primary antibodies. Recommended dilution of 1:500.</td>
		</tr>
		<tr>
			<td>Streptavidin-ALEXA 647</td>
			<td>Thermo</td>
			<td>S32357</td>
			<td>Used as secondary antibody to label biotinylated primary antibodies. Recommended dilution of 1:500.</td>
		</tr>
		<tr>
			<td>Surgical Scissors, sharp</td>
			<td>FST</td>
			<td>14002-12</td>
			<td>Used for removal of muscle and skin</td>
		</tr>
		<tr>
			<td>Surgical Scissors, sharp-blunt</td>
			<td>FST</td>
			<td>14001-16</td>
			<td>Used for decapitation (except pig and macaque)</td>
		</tr>
		<tr>
			<td>Swinnex Filter Holder, 13 mm</td>
			<td>Millipore Sigma</td>
			<td>SX0001300</td>
			<td>Modified by laser-cut. Used for small vetebrate hypothalus and pituitary.</td>
		</tr>
		<tr>
			<td>Swinnex Filter Holder, 25 mm</td>
			<td>Millipore Sigma</td>
			<td>SX0002500</td>
			<td>Modified by laser-cut. Used on most small vertebrates CNS tissues, except hypothalamus and pituitary. Used for macaque and pig hypothalamus and pituitary.</td>
		</tr>
		<tr>
			<td>Swinnex Filter Holder, 47 mm</td>
			<td>Millipore Sigma</td>
			<td>SX0004700</td>
			<td>Modified by laser-cut. Used for macaque and pig CNS tissues, except hypothalamus and pituitary.</td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>ThermoFisher</td>
			<td>50-165-7277</td>
			<td>Used for blocking and antibody diluent.</td>
		</tr>
		<tr>
			<td>Wheaton 120 Vac Overhead Stirrer</td>
			<td>VWR (Supplier DWK Life Sciences)</td>
			<td>62400-904 (DWK #903475)</td>
			<td>Used for macaque and pig CNS tissues with 55 mL tissue grinder, except hypothalamus and pituitary.</td>
		</tr>
		<tr>
			<td>Wheaton Potter-Elvehjem tissue grinder with PTFE pestle, 10 mL</td>
			<td>VWR (Supplier DWK Life Sciences)</td>
			<td>14231-384 (DWK #357979)</td>
			<td>Used on most small vertebrates CNS tissues, except hypothalamus and pituitary. Used for macaque and pig hypothalamus and pituitary.</td>
		</tr>
		<tr>
			<td>Wheaton Potter-Elvehjem tissue grinder with PTFE pestle, 55 mL</td>
			<td>VWR (Supplier DWK Life Sciences)</td>
			<td>14231-372 (DWK #357994)</td>
			<td>Used for macaque and pig CNS tissues, except hypothalamus and pituitary.</td>
		</tr>
	</tbody>
</table>

reliable isolation of central nervous system microvessels across five vertebrate groups

Isolation of microvessels from the central nervous system (CNS) is commonly performed by combining cortical tissue from multiple animals, most often rodents. This approach limits the interrogation of blood-brain barrier (BBB) properties to the cortex and does not allow for individual comparison. This project focuses on the development of an isolation method that allows for the comparison of the neurovascular unit (NVU) from multiple CNS regions: cortex, cerebellum, optic lobe, hypothalamus, pituitary, brainstem, and spinal cord. Moreover, this protocol, originally developed for murine samples, was successfully adapted for use on CNS tissues from small and large vertebrate species from which we are also able to isolate microvessels from brain hemisphere white matter. This method, when paired with immunolabeling, allows for quantitation of protein expression and statistical comparison between individuals, tissue type, or treatment. We proved this applicability by evaluating changes in protein expression during experimental autoimmune encephalomyelitis (EAE), a murine model of a neuroinflammatory disease, multiple sclerosis. Additionally, microvessels isolated by this method could be used for downstream applications like qPCR, RNA-seq, and Western blot, among others. Even though this is not the first attempt to isolate CNS microvessels without the use of ultracentrifugation or enzymatic dissociation, it is unique in its adeptness for the comparison of single individuals and multiple CNS regions. Therefore, it allows for investigation of a range of differences that may otherwise remain obscure: CNS portions (cortex, cerebellum, optic lobe, brainstem, hypothalamus, pituitary, and spinal cord), CNS tissue type (gray or white matter), individuals, experimental treatment groups, and species.

Microvessels isolated from murine CNS showed all intrinsic cellular components of the neurovascular unit2,3. Using either platelet endothelial cell adhesion molecule-1 (PECAM, also known as CD31) or isolectin IB4 (a glycoprotein that binds the endothelial cell glycocalyx) for endothelial cells, platelet derived growth factor-&#946; (PDGFR&#946;) or neuron-glial antigen 2 (NG2) for pericytes and aquaporin-4 (AQP4) for astrocytic en...

Watch this Scientific Journal Video about Reliable Isolation of Central Nervous System Microvessels Across Five Vertebrate Groups at JoVE.com

Reliable Isolation of Central Nervous System Microvessels Across Five Vertebrate Groups

The goal of this protocol is to isolate microvessels from multiple regions of the central nervous system of lissencephalic and gyrencephalic vertebrates.

Isolation of microvessels from the central nervous system (CNS) is commonly performed by combining cortical tissue from multiple animals, most often ...

This protocol is significant because it allows for the comparison of microvasculature between different central nervous system regions, as well as between different individuals. This microvessel isolation technique can be completed within a single day, and it eliminates the need for ultracentrifugation and enzymatic dissociation. Removing the meninges and the choroid plexus can be difficult.Be sure to work slowly and carefully to ensure the complete removal of each tissue. For CNS tissue dissection from a small lissencephalic vertebrate specimen, place the harvested brain into a 15 milliliter conical tube containing MV-1 solution on ice, and use forceps to retrieve the pituitary from the sella turcica of the skull. Place the pituitary in a 1.7 milliliter microcentrifuge tube of MV-1 solution on ice, and remove the skin and muscle to expose the vertebral column.After removing the limbs, ribcage and internal organs, use a 10 milliliter syringe equipped with an 18 gauge needle to flush the vertebral column with fresh MV-1 solution, in a caudal-to-rostral direction throughout the lumbar vertebral foramen. Then place the spinal cord in a 5 milliliter tube containing fresh MV-1 solution. Next, place the brain into a Petri dish under the dissecting microscope, and remove the meninges with double-pronged prick.Be sure to check the spinal cord to ensure that no pieces of meninges are remaining. Use the forceps to separate the hypothalamus, cerebellum, brain stem, and cortex. When necessary, use forceps and iris and spring scissors to excise the olfactory bulbs and thalamus, and use the double-pronged prick to remove all of the choroid plexus from all the brain ventricles.For CNS tissue dissection from a large gyrencephalic vertebrate specimen, use a dissecting microscope and a double-pronged prick, forceps, and iris and spring scissors to remove the meninges from each CNS tissue, taking care to remove any pieces of choroid plexus from the brain ventricles. For homogenization of the harvested CNS tissues, mince each CNS region into one to two millimeter pieces within individual Petri dishes. To homogenize CNS tissues from small vertebrate specimens, use a transfer pipette to add one milliliter of MV-1 solution to suspend the minced tissue.Then use the same transfer pipette to dispense the cortex, cerebellum, brain stem, optic lobe, and spinal cord pieces into individual 10 milliliter glass tissue grinders, and use a PTFE pestle and five milliliters of MV-1 solution to grind each set of tissues for about 10 strokes. Transfer each tissue slurry into individual 15 milliliter conical tubes on ice, and use forceps to place the hypothalamus and pituitary in 100 microliters of MV-1 solution, in individual 1.7 milliliter tubes. Then, carefully homogenize each tissue with a glass micropestle.To homogenize a large vertebrate specimen, use a beveled cut transfer pipette to transfer the minced tissue to a 55 milliliter glass tissue grinder, and attach the grinder to an overhead stirrer. Add half of the recommended volume of MV-1 solution according to the specific CNS portion being homogenized as indicated in the table, and turn on the overhead stirrer to approximately 150 rotations per minute. Carefully move the glass tube up and down for about 30 seconds before turning off the overhead stirrer to add more MV-1 solution for additional homogenization, until a homogenous slurry is obtained.Then transfer the homogenized tissue to a 50 milliliter conical tube on ice. For microvessel purification, pellet the CNS tissue homogenates by centrifugation, and discard the supernatants. For a small vertebrate specimen microvessel isolation, pipette the cortex, cerebellum, brain stem, optic lobe and spinal cord pellets, in five milliliters of fresh, ice-cold MV-2 solution per sample, about 10 times, before adding five more milliliters of ice-cold MV-2 solution to each tube.Carefully flip the tubes to mix, and re-suspend the hypothalamus and pituitary pellets in one milliliter of MV-2 solution. For large vertebrate specimen microvessel isolation, add 20 milliliters of ice-cold MV-2 solution to the cortex, cerebellum, brain stem, and spinal cord microvessel pellets, and re-suspend the pellets in a tube revolver at 40 rotations per minute for about 5 minutes. At the end of re-suspension, separate the CNS tissue lycates by centrifugation, and slowly rotate each tube to allow the supernatant to pass along the wall to carefully detach the thick and dense myelin layer on the liquid interface from the tube walls.Discard the myelin and liquid interfaces, and blot the inside wall of each tube with a spatula wrapped with a low-lint paper wipe. Then, use a twisted low-lint paper wipe to absorb excess liquid, and use low-binding tips to re-suspend each pellet in one milliliter of MV-3 solution. For microvessel elution and filtration, mix a few milliliters of fresh MV-3 solution to each CNS tissue microvessel slurry, and while mixing to avoid aggregates, strain each suspension through a Pruitt strainer into individual 50 milliliter conical tubes.Place one 20 micrometer nylon net filter onto one modified filter holder per CNS region. Transfer the filter holder onto a 50 milliliter conical tube, and wet the filter with five milliliters of ice-cold MV-3 solution, making sure that the buffer pours down the filter holder, into the conical tube. Transfer the eluted microvessels onto each 20 micrometer nylon net filter, and rinse the microvessels with five to 10 milliliters of ice-cold MV-3 solution.Use forceps to transfer each filter into individual beakers containing the ice-cold MV-3 solution, and gently shake each filter for about 30 seconds to detach the microvessels. After transferring to a 15 milliliter conical tube, collect the microvessels by centrifugation, and use a low-binding pipette to re-suspend each pellet in one milliliter of ice-cold MV-3 solution. Then, transfer microvessel suspensions from small vertebrate specimens into a 1.7 milliliter microcentrifuge tube for centrifugation for five minutes at 20, 000 times G, in four degrees celsius.For large vertebrate specimens, transfer the suspension into individual five milliliter centrifuge tubes, and add four milliliters of MV-3 solution for centrifugation for five minutes at 2, 000 times G in four degrees celsius. The intrinsic components of the neurovascular unit can be detected within microvessels, isolated as demonstrated, by immunolabeling for CD31, PDGFR-beta, and aquaporin four, including the cortical, cerebellar, pituitary, hypothalamic, brain stem, and spinal microvessels. Likewise, the expression of adherens-junction protein VE-cadherin, tight junction proteins CLDN5 and Zonula Occludens-1, tricellular junction protein angulin-1, and basal markes chemokine ligand CXCL motif 12, and gamma-glutamyltransferase-1, can be visualized.Moreover, the majority of the microvessels are devoid of the expression of alpha smooth muscle actin, indicating that this isolation protocol selectively targets small-caliber microvessels. Microvessels obtained from other small lissencephalic vertebrates, like bird, liard, frog, and fish, share some morphological features, suggesting that this method is useful for further characterization of differences in neurovascular units between species. Quantification of the changes in protein expression reveals an increase in vascular cell adhesion molecule one, and junctional adhesion molecule B along spinal cord microvessels, during the peak of experimental autoimmune encephalomyelitis.However, vascular cell adhesion molecule one is also significantly increased in pituitary microvessels, and decreased in the hypothalamus and brainstem microvessels. In addition, changes are observed in vascular cell adhesion molecule one expression during chronic experimental autoimmune encephalomyelitis in all CNS tissues, and in junctional adhesion molecule B expression in the hypothalamus and pituitary microvessels. Quantitative analyses, such as western blot, PCR and immunohistochemistry, can be performed following this procedure to reveal insights into gene and protein expression patterns within the blood-brain barrier.Paraformaldehyde is an acutely toxic reagent, and should always be handled under the fume hood while wearing proper PPE.

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Neuroscience

8.4K visualizações.  University of California Davis. Este protocolo é significativo porque permite a comparação da microvasculatura entre diferentes regiões do sistema nervoso central, bem como entre diferentes indivíduos. Esta técnica de isolamento de microvessel pode ser completada dentro de um único dia, e elimina a necessidade de ultracentrifugação e dissociação enzimática. Remover as meninges e o plexo coroide pode ser difícil.Certifique-se de trabalhar devagar e com cuidado para garantir a remoção completa de cada te...