Name: culture of brain capillary pericytes for cytosolic calcium measurements and calcium imaging studies
Uploaded: 2020-05-27T15:00:00
Description: Watch this Scientific Journal Video about Culture of Brain Capillary Pericytes for Cytosolic Calcium Measurements and Calcium Imaging Studies at JoVE.com

The authors wish to acknowledge funding from the Lundbeck Foundation Research initiative on Brain Barriers and Drug Delivery (RIBBDD) and Simon Hougners Family Foundation.

1. Preparation of buffers and solutions for cell culturing
<ol>
	<li>Prepare collagen stock solution by dissolving 5 mg of collagen IV from human placenta in 50 mL of PBS overnight at 4 &#176;C. Aliquot the stock solution into 5 mL portions and store at -20 &#176;C.</li>
	<li>Prepare fibronectin stock solution by dissolving 5 mg of fibronectin in 5 mL of sterile water overnight. Store the fibronectin stocks in aliquots of 500 &#181;L at -20 &#176;C. When thawing, add PBS to a final volume of 50 mL to prepare the work s...

<ol>
	<li>Armulik, A., Genove, G., Betsholtz, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pericytes:+Developmental,+Physiological,+and+Pathological+Perspectives,+Problems,+and+Promises.">Pericytes: Developmental, Physiological, and Pathological Perspectives, Problems, and Promises.</a> Developmental Cell. 21 (2), 193-215 (2011).</li><li>Abbott, N. J., Ronnback, L., Hansson, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Astrocyte-endothelial+interactions+at+the+blood-brain+barrier.">Astrocyte-endothelial interactions at the blood-brain barrier.</a> Nature Reviews Neuroscience. 7 (1), 41-53 (2006).</li><li>Mathiisen, T. M., Lehre, K. P., Danbolt, N. C., Ottersen, O. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Perivascular+Astroglial+Sheath+Provides+a+Complete+Covering+of+the+Brain+Microvessels:+An+Electron+Microscopic+3D+Reconstruction.">The Perivascular Astroglial Sheath Provides a Complete Covering of the Brain Microvessels: An Electron Microscopic 3D Reconstruction.</a> Glia. 58 (9), 1094-1103 (2010).</li><li>Helms, H. 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=In+vitro+models+of+the+blood-brain+barrier:+An+overview+of+commonly+used+brain+endothelial+cell+culture+models+and+guidelines+for+their+use.">In vitro models of the blood-brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use.</a> Journal of Cerebral Blood Flow and Metabolism. 36 (5), 862-890 (2016).</li><li>Zhou, L., Sohet, F., Daneman, R. <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+Pericytes+from+Rodent+Optic+Nerve+by+Immunopanning.">Purification of Pericytes from Rodent Optic Nerve by Immunopanning.</a> Cold Spring Harbor Protocols. , 608-617 (2014).</li><li>Liu, G. H., 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=Isolation,+Purification,+and+Cultivation+of+Primary+Retinal+Microvascular+Pericytes:+A+Novel+Model+Using+Rats.">Isolation, Purification, and Cultivation of Primary Retinal Microvascular Pericytes: A Novel Model Using Rats.</a> Microcirculation. 21 (6), 478-489 (2014).</li><li>Nayak, R. C., Herman, I. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bovine+retinal+microvascular+pericytes:+isolation,+propagation,+and+identification.">Bovine retinal microvascular pericytes: isolation, propagation, and identification.</a> Methods In Molecular Medicine. 46, 247-263 (2001).</li><li>Nees, 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=Isolation,+bulk+cultivation,+and+characterization+of+coronary+microvascular+pericytes:+the+second+most+frequent+myocardial+cell+type+in+vitro.">Isolation, bulk cultivation, and characterization of coronary microvascular pericytes: the second most frequent myocardial cell type in vitro.</a> American Journal of Physiology-Heart and Circulatory Physiology. 302 (1), H69-H84 (2012).</li><li>Armulik, A., Abramsson, A., Betsholtz, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endothelial/pericyte+interactions.">Endothelial/pericyte interactions.</a> Circulation Research. 97 (6), 512-523 (2005).</li><li>Helms, H. C., Brodin, B., Milner, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+in+Molecular+Biology.">Methods in Molecular Biology.</a> Cerebral Angiogenesis: Methods and Protocols. 1135, 365-382 (2014).</li><li>Abbracchio, M. P., Burnstock, G., Verkhratsky, A., Zimmermann, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Purinergic+signalling+in+the+nervous+system:+an+overview.">Purinergic signalling in the nervous system: an overview.</a> Trends in Neurosciences. 32 (1), 19-29 (2009).</li><li>Cai, 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=Stimulation-induced+rises+in+cerebral+blood+flow+and+local+capillary+vasoconstriction+depend+on+conducted+vascular+responses+in+brain+capillaries.">Stimulation-induced rises in cerebral blood flow and local capillary vasoconstriction depend on conducted vascular responses in brain capillaries.</a> PNAS. , (2018).</li><li>Tigges, U., Welser-Alves, J. V., Boroujerdi, A., Milner, R. <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+and+simple+method+for+culturing+pericytes+from+mouse+brain.">A novel and simple method for culturing pericytes from mouse brain.</a> Microvascular Research. 84 (1), 74-80 (2012).</li><li>Maier, C. L., Shepherd, B. R., Yi, T., Pober, 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=Explant+Outgrowth,+Propagation+and+Characterization+of+Human+Pericytes.">Explant Outgrowth, Propagation and Characterization of Human Pericytes.</a> Microcirculation. 17 (5), 367-380 (2010).</li><li>Orlidge, A., Damore, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+specific+effects+of+glycosaminoglycans+on+the+attachment+and+proliferation+of+vascular+wall+components.">Cell specific effects of glycosaminoglycans on the attachment and proliferation of vascular wall components.</a> Microvascular Research. 31 (1), 41-53 (1986).</li><li>Rhinehart, K., Zhang, Z., Pallone, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ca2++signaling+and+membrane+potential+in+descending+vasa+recta+pericytes+and+endothelia.">Ca2+ signaling and membrane potential in descending vasa recta pericytes and endothelia.</a> American Journal of Physiology-Renal Physiology. 283, F852-F860 (2002).</li><li>Bintig, W., 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=Purine+receptors+and+Ca2++signalling+in+the+human+blood-brain+barrier+endothelial+cell+line+hCMEC/D3.">Purine receptors and Ca2+ signalling in the human blood-brain barrier endothelial cell line hCMEC/D3.</a> Purinergic Signalling. 8 (1), 71-80 (2012).</li><li>Neuhaus, A. A., Couch, Y., Sutherland, B. A., Buchan, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+method+to+study+pericyte+contractility+and+responses+to+ischaemia+in+vitro+using+electrical+impedance.">Novel method to study pericyte contractility and responses to ischaemia in vitro using electrical impedance.</a> Journal of Cerebral Blood Flow and Metabolism. 37 (6), 2013-2024 (2017).</li><li>Kamouchi, M., 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=Calcium+influx+pathways+in+rat+CNS+pericytes.">Calcium influx pathways in rat CNS pericytes.</a> Molecular Brain Research. 126 (2), 114-120 (2004).</li><li>Das, A., 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=ATP+Causes+Retinal+Pericytes+to+Contract+In+vitro.">ATP Causes Retinal Pericytes to Contract In vitro.</a> Experimental Eye Research. 46, 349-362 (1988).</li></ol>

In this study, we have presented a method to isolate primary pericytes from bovine brains. The described protocol allows culture of this otherwise rather inaccessible cell type. The subsequently obtained cell culture was a nearly homogenous population of pericytes, with little or no contamination with endothelial cells&#160;and glial cells based on cell morphology and protein expression12. Furthermore, we demonstrated a simple and straightforward method to load the pericytes with calcium dyes for ...

Brain capillary pericytes, together with endothelial cells and astrocytes, constitute the NVU1,2,3. The endothelial cells, which form the structural basis of the capillaries, form long cylindrical tubes with a diameter of 5-8 &#181;m. The endothelial cells are sporadically covered with pericytes and surrounded by protrusions from astrocytes; the astrocyte endfeet.
The blood-brain barrier (BBB), situated at the brain capillaries, is the main site for exchange of nutrients, gases and waste products between the brain and the blood. The BBB also protects the brain from endogenous and exogenous neurotoxins and serves as a barrier for the delivery of a large number of drug compounds. The barrier function is a focus area, as well as an obstacle, for drug companies developing central nervous system (CNS) medicines. This has spurred a large interest in investigating the cells of the NVU in culture4. Brain astrocytes and endothelial cells have been cultured and characterized in a number of studies, whereas the studies and protocols for pericyte culture are sparse.
Previously published protocols have described generation of brain capillary pericyte cultures to some degree, using a range of different approaches such as immunopanning5, high- and low-glucose media6, fluorescent-activated cell sorting7, density gradient centrifugation8, etc. Although these methods seem sufficient to obtain cultures of pericytes, some are time consuming, cost expensive and the pericytes obtained might not be ideal due to the number of culture passages that can de-differentiate the pericytes9. Furthermore, the potential of cultured pericytes in in vitro signaling studies has been fairly unexplored until now.
The present work focuses on the generation of pericyte cultures from isolated bovine brain capillaries and the subsequent setup for measurements and imaging studies of changes in intracellular calcium, an important intracellular second messenger. We briefly describe the isolation of capillaries from cortical gray matter (for details see Helms et al.10) and the isolation and culture of pericytes in pure monoculture without contamination with endothelial or glial cells. We then provide a protocol for seeding of pericytes in 96-well plates and loading protocols for the calcium probe Fura-2 AM. Finally, we show how pericytes can be used in real-time confocal imaging in microscope culture chambers and describe the protocols for this.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>ATP</td>
			<td>Tocris</td>
			<td>3245</td>
			<td></td>
		</tr>
		<tr>
			<td>Cal-520 AM</td>
			<td>AAT Bioquest</td>
			<td>21130</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell incubator</td>
			<td>Thermo Fisher</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Thermo Fisher</td>
			<td>Heraeus Multifuge 3SR+</td>
			<td>Standard large volume centrifuge for spinning down cells</td>
		</tr>
		<tr>
			<td>Collagen IV</td>
			<td>Sigma Aldrich</td>
			<td>C5533</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal laser scanning microscope</td>
			<td>Carl Zeiss</td>
			<td>Zeiss LSM 510</td>
			<td>Inverted microscope</td>
		</tr>
		<tr>
			<td>Counting chamber</td>
			<td>FastRead</td>
			<td>102</td>
			<td></td>
		</tr>
		<tr>
			<td>Coverslip cell chamber</td>
			<td>Airekacells</td>
			<td>SC15022</td>
			<td></td>
		</tr>
		<tr>
			<td>Cremophor EL</td>
			<td>Sigma Aldrich</td>
			<td>C5135</td>
			<td>Formerly known as Kolliphor EL</td>
		</tr>
		<tr>
			<td>DMSO</td>
			<td>Sigma Aldrich</td>
			<td>471267</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagles Medium</td>
			<td>Sigma Aldrich</td>
			<td>D0819</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal bovine serum (FBS)</td>
			<td>PAA/GE Healthcare</td>
			<td>A15-101</td>
			<td></td>
		</tr>
		<tr>
			<td>Fibronectin</td>
			<td>Sigma Aldrich</td>
			<td>F1141</td>
			<td></td>
		</tr>
		<tr>
			<td>Fura-2 AM</td>
			<td>Thermo Fisher</td>
			<td>F1201</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass coverslips 22x22 mm</td>
			<td>VWR International</td>
			<td>631-0123</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS</td>
			<td>Gibco</td>
			<td>14065-049</td>
			<td></td>
		</tr>
		<tr>
			<td>Heparin</td>
			<td>Sigma Aldrich</td>
			<td>H3149</td>
			<td></td>
		</tr>
		<tr>
			<td>HEPES</td>
			<td>AppliChem Panreac</td>
			<td>A1069</td>
			<td></td>
		</tr>
		<tr>
			<td>Light microscope</td>
			<td>Olympus</td>
			<td>Olympus CK2</td>
			<td>Upright light microscope with phase contrast</td>
		</tr>
		<tr>
			<td>MEM nonessential amino acids</td>
			<td>Sigma Aldrich</td>
			<td>M7145</td>
			<td></td>
		</tr>
		<tr>
			<td>Microplate Reader</td>
			<td>BMG LabTech</td>
			<td>NOVOstar</td>
			<td></td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>Sigma Aldrich</td>
			<td>D8537</td>
			<td>Phosphate-buffered saline</td>
		</tr>
		<tr>
			<td>penicillin G sodium/streptomycin sulfate</td>
			<td>Sigma Aldrich</td>
			<td>P0781</td>
			<td></td>
		</tr>
		<tr>
			<td>Pluronic F127</td>
			<td>Sigma Aldrich</td>
			<td>P2443</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA</td>
			<td>Sigma Aldrich</td>
			<td>T4299</td>
			<td></td>
		</tr>
		<tr>
			<td>T-75 flask</td>
			<td>Sigma Aldrich</td>
			<td>CLS3972</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well plate</td>
			<td>Corning incorporated</td>
			<td>3603</td>
			<td></td>
		</tr>
	</tbody>
</table>

culture of brain capillary pericytes for cytosolic calcium measurements and calcium imaging studies

Pericytes are associated with endothelial cells and astrocytic endfeet in a structure known as the neurovascular unit (NVU). Brain capillary pericyte function is not fully known. Pericytes have been suggested to be involved in capillary development, regulation of endothelial barrier tightness and trancytosis activity, regulation of capillary tone and to play crucial roles in certain brain pathologies.
Pericytes are challenging to investigate in the intact brain due to the difficulties in visualizing processes in the brain parenchyma, as well as the close proximity to the other cells of the NVU. The present protocol describes a method for isolation and culture of primary bovine brain capillary pericytes and their following usage in calcium imaging studies, where effects of agonists involved in brain signaling and pathologies can be investigated. Cortical capillary fragments are allowed to attach to the bottom of culture flasks and, after 6 days, endothelial cells and pericytes have grown out from the capillary fragments. The endothelial cells are removed by gentle trypsinization and pericytes are cultured for 5 additional days before passaging.
Isolated pericytes are seeded in 96-well culture plates and loaded with the calcium indicator dye (Fura-2 acetoxymethyl (AM)) to allow for measurements of intracellular calcium levels in a plate reader setup. Alternatively, pericytes are seeded on coverslips and mounted in cell chambers. Following loading with the calcium indicator (Cal-520 AM), calcium live-imaging can be performed using confocal microscopy at an excitation wavelength of 488 nm and emission wavelength of 510-520 nm.
The method described here has been used to obtain the first intracellular calcium measurements from primary brain capillary pericytes, demonstrating that pericytes are stimulated via ATP and are able to contract in vitro.

Bovine brain capillaries were isolated from fresh brain tissue and Figure 1 presents the capillary seeding and cellular outgrowth over days and subsequent purification&#160;of pericytes. The capillaries are fully attached to the flask at day 1 and on day 2 endothelial sprouting has become visible (Figure 1, day 2). After 4 days, the cellular outgrowth is highly distinctive (Figure 1, day 4a) and the ...

Watch this Scientific Journal Video about Culture of Brain Capillary Pericytes for Cytosolic Calcium Measurements and Calcium Imaging Studies at JoVE.com

Culture of Brain Capillary Pericytes for Cytosolic Calcium Measurements and Calcium Imaging Studies

Brain capillary pericytes are essential players in the regulation of blood-brain barrier properties and blood flow. This protocol describes how brain capillary pericytes can be isolated, cultured, characterized with respect to cell type and applied for investigations of intracellular calcium signaling with fluorescent probes.

Pericytes are associated with endothelial cells and astrocytic endfeet in a structure known as the neurovascular unit (NVU). Brain capillary pericyte ...

Research

JoVE Journal

Neuroscience

Functional Calcium Imaging in Developing Cortical Networks

A hallmark pattern of activity in developing nervous systems is spontaneous, synchronized network activity. Synchronized activity has been observed in ...

Preparation of Acute Subventricular Zone Slices for Calcium Imaging

The subventricular zone (SVZ) is one of the two neurogenic zones in the postnatal brain. The SVZ contains densely packed cells, including neural ...

Simultaneous Electrophysiological Recording and Calcium Imaging of Suprachiasmatic Nucleus Neurons

Simultaneous electrophysiological and fluorescent imaging recording methods were used to study the role of changes of membrane potential or current in ...

Two-photon Calcium Imaging in Neuronal Dendrites in Brain Slices

Calcium (Ca2+) imaging is a powerful tool to investigate the spatiotemporal dynamics of intracellular Ca2+ signals in neuronal dendrites. Ca2+ ...

Ablation of a Neuronal Population Using a Two-photon Laser and Its Assessment Using Calcium Imaging and Behavioral Recording in Zebrafish Larvae

To identify the role of a subpopulation of neurons in behavior, it is essential to test the consequences of blocking its activity in living animals. Laser ...

Ex Vivo Calcium Imaging for Visualizing Brain Responses to Endocrine Signaling in Drosophila

Ex Vivo Calcium Imaging for Visualizing Brain Responses to Endocrine Signaling in Drosophila

Organ-to-organ communication by endocrine signaling, for example, from the periphery to the brain, is essential for maintaining homeostasis. As a model ...

Brain Pericyte Calcium and Hemodynamic Imaging in Transgenic Mice In Vivo

Brain Pericyte Calcium and Hemodynamic Imaging in Transgenic Mice In Vivo

Recent advances in protein biology and mouse genetics have made it possible to measure intracellular calcium fluctuations of brain cells in vivo and to ...

Stereotaxic Viral Injection and Gradient-Index Lens Implantation for Deep Brain In Vivo Calcium Imaging

Stereotaxic Viral Injection and Gradient-Index Lens Implantation for Deep Brain In Vivo Calcium Imaging

A miniature fluorescence microscope (miniscope) is a potent tool for in vivo calcium imaging from freely behaving animals. It offers several advantages ...

Subcellular Imaging of Neuronal Calcium Handling In Vivo

Subcellular Imaging of Neuronal Calcium Handling In Vivo

Calcium (Ca2+) imaging has been largely used to examine neuronal activity, but it is becoming increasingly clear that subcellular Ca2+ handling is a ...

Two-Photon and Wide-Field Calcium Imaging in the Superior Colliculus

Calcium Imaging in Mouse Superior Colliculus

Unveiling Neural Coding and Mechanisms of Visual Processing in the Superior Colliculus (Video) | JoVE

The superior colliculus (SC), an evolutionarily conserved midbrain structure in all vertebrates, is the most sophisticated visual center before the ...