Name: rapid isolation of dorsal root ganglion macrophages
Uploaded: 2019-09-07T14:30:00
Description: Watch this Scientific Journal Video about Rapid Isolation of Dorsal Root Ganglion Macrophages at JoVE.com

The study was supported by: Foundation for Anesthesia Education and Research (XY); the UCSF Department of Anesthesia and Perioperative Care (XY); and 1R01NS100801-01(GZ). This study was supported in part by HDFCCC Laboratory for Cell Analysis Shared Resources Facility through a grant from the NIH (P30CA082103).

All animal experiments were approved by the Institutional Animal Care and Use Committee at the University of California San Francisco and were conducted in accordance with the NIH Guide for the Care and Use of Laboratory Animals.
1. Collect lumbar DRG from experimental mice
<ol>
	<li>Before starting the experiment, prepare the working solution of the density gradient medium (e.g., Percoll) by mixing 9 volumes of the medium with 1 volume of Ca++/Mg++-free 10x HBSS. Keep ...

<ol>
	<li>Ji, R. R., Chamessian, A., Zhang, Y. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pain+regulation+by+non-neuronal+cells+and+inflammation.">Pain regulation by non-neuronal cells and inflammation.</a> Science. 354 (6312), 572-577 (2016).</li><li>Inoue, K., Tsuda, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microglia+in+neuropathic+pain:+cellular+and+molecular+mechanisms+and+therapeutic+potential.">Microglia in neuropathic pain: cellular and molecular mechanisms and therapeutic potential.</a> Nature Reviews Neurosciences. 19 (3), 138-152 (2018).</li><li>Hu, P., McLachlan, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+functional+types+of+macrophage+in+dorsal+root+ganglia+and+spinal+nerves+proximal+to+sciatic+and+spinal+nerve+transections+in+the+rat.">Distinct functional types of macrophage in dorsal root ganglia and spinal nerves proximal to sciatic and spinal nerve transections in the rat.</a> Experimental Neurology. 184 (2), 590-605 (2003).</li><li>Simeoli, R., Montague, K., Jones, H. R., 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=Exosomal+cargo+including+microRNA+regulates+sensory+neuron+to+macrophage+communication+after+nerve+trauma.">Exosomal cargo including microRNA regulates sensory neuron to macrophage communication after nerve trauma.</a> Nature Communication. 8 (1), 1778 (2017).</li><li>Cobos, E. J., Nickerson, C. A., Gao, F., 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=Mechanistic+differences+in+neuropathic+pain+modalities+revealed+by+correlating+behavior+with+global+expression+profiling.">Mechanistic differences in neuropathic pain modalities revealed by correlating behavior with global expression profiling.</a> Cell Reports. 22 (5), 1301-1312 (2018).</li><li>Zhang, H., Li, Y., de Carvalho-Barbosa, 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=Dorsal+Root+Ganglion+Infiltration+by+Macrophages+Contributes+to+Paclitaxel+Chemotherapy-Induced+Peripheral+Neuropathy.">Dorsal Root Ganglion Infiltration by Macrophages Contributes to Paclitaxel Chemotherapy-Induced Peripheral Neuropathy.</a> The Journal of Pain. 17 (7), 775-786 (2016).</li><li>Liu, T., van Rooijen, N., Tracey, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Depletion+of+macrophages+reduces+axonal+degeneration+and+hyperalgesia+following+nerve+injury.">Depletion of macrophages reduces axonal degeneration and hyperalgesia following nerve injury.</a> Pain. 86 (1-2), 25-32 (2000).</li><li>Peng, J., Gu, N., Zhou, 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=Microglia+and+monocytes+synergistically+promote+the+transition+from+acute+to+chronic+pain+after+nerve+injury.">Microglia and monocytes synergistically promote the transition from acute to chronic pain after nerve injury.</a> Nature Communication. 7, 12029 (2016).</li><li>Barclay, J., Clark, A. K., Ganju, 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=Role+of+the+cysteine+protease+cathepsin+S+in+neuropathic+hyperalgesia.">Role of the cysteine protease cathepsin S in neuropathic hyperalgesia.</a> Pain. 130 (3), 225-234 (2007).</li><li>Lim, H., Lee, H., Noh, K., Lee, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=IKK/NF-kappaB-dependent+satellite+glia+activation+induces+spinal+cord+microglia+activation+and+neuropathic+pain+after+nerve+injury.">IKK/NF-kappaB-dependent satellite glia activation induces spinal cord microglia activation and neuropathic pain after nerve injury.</a> Pain. 158 (9), 1666-1677 (2017).</li><li>Rutkowski, M. D., Pahl, J. L., Sweitzer, S., van Rooijen, N., DeLeo, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limited+role+of+macrophages+in+generation+of+nerve+injury-induced+mechanical+allodynia.">Limited role of macrophages in generation of nerve injury-induced mechanical allodynia.</a> Physiology and Behavior. (3-4), 225-235 (2000).</li><li>Kwon, M. J., Shin, H. Y., Cui, 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=CCL2+Mediates+Neuron-Macrophage+Interactions+to+Drive+Proregenerative+Macrophage+Activation+Following+Preconditioning+Injury.">CCL2 Mediates Neuron-Macrophage Interactions to Drive Proregenerative Macrophage Activation Following Preconditioning Injury.</a> Journal of Neuroscience. 35 (48), 15934-15947 (2015).</li><li>Zigmond, R. E., Echevarria, F. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Macrophage+biology+in+the+peripheral+nervous+system+after+injury.">Macrophage biology in the peripheral nervous system after injury.</a> Progress in Neurobiology. 173, 102-121 (2019).</li><li>Ghasemlou, N., Chiu, I. M., Julien, J. P., Woolf, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CD11b+Ly6G-+myeloid+cells+mediate+mechanical+inflammatory+pain+hypersensitivity.">CD11b+Ly6G- myeloid cells mediate mechanical inflammatory pain hypersensitivity.</a> Proceedings of the National Academy of Science USA. 112 (49), E6808-E6817 (2015).</li><li>Malin, S. A., Davis, B. M., Molliver, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+dissociated+sensory+neuron+cultures+and+considerations+for+their+use+in+studying+neuronal+function+and+plasticity.">Production of dissociated sensory neuron cultures and considerations for their use in studying neuronal function and plasticity.</a> Nature Protocols. 2 (1), 152-160 (2007).</li><li>Lin, Y. T., Chen, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dorsal+Root+Ganglia+Isolation+and+Primary+Culture+to+Study+Neurotransmitter+Release.">Dorsal Root Ganglia Isolation and Primary Culture to Study Neurotransmitter Release.</a> Journal of Visualized Experiment. (140), (2018).</li><li>Burnett, S. H., Kershen, E. J., Zhang, 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=Conditional+macrophage+ablation+in+transgenic+mice+expressing+a+Fas-based+suicide+gene.">Conditional macrophage ablation in transgenic mice expressing a Fas-based suicide gene.</a> J Leukoc Biol. 75 (4), 612-623 (2004).</li><li>Lopes, D. M., Malek, N., Edye, 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=Sex+differences+in+peripheral+not+central+immune+responses+to+pain-inducing+injury.">Sex differences in peripheral not central immune responses to pain-inducing injury.</a> Science Reports. 7 (1), 16460 (2017).</li><li>Kim, Y. S., Anderson, M., Park, 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=Coupled+Activation+of+Primary+Sensory+Neurons+Contributes+to+Chronic+Pain.">Coupled Activation of Primary Sensory Neurons Contributes to Chronic Pain.</a> Neuron. 91 (5), 1085-1096 (2016).</li><li>Vicuna, L., Strochlic, D. E., Latremoliere, 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=The+serine+protease+inhibitor+SerpinA3N+attenuates+neuropathic+pain+by+inhibiting+T+cell-derived+leukocyte+elastase.">The serine protease inhibitor SerpinA3N attenuates neuropathic pain by inhibiting T cell-derived leukocyte elastase.</a> Nature Medicine. 21 (5), 518-523 (2015).</li></ol>

Here we introduce a new method to effectively enrich isolated macrophages from mouse DRG. The conventional approach to isolate DRG immune cells requires enzymatic digestion15,18, which is now replaced with mechanical homogenization in our protocol to limit undesired cell damage and increase the yield. Therefore, the new protocol is far less time consuming. More importantly, enzyme digestion might stimulate the macrophages and change the molecular signature. In co...

There is now considerable evidence that immune cells contribute to the neuropathic pain following peripheral nerve injury1,2. Peripheral monocytic cells, including mature macrophages, are known to respond to tissue injury and systemic infection through phagocytosis, antigen presentation, and cytokine release. Paralleling the nerve injury-induced microglia activation in the spinal dorsal horn, macrophages in the dorsal root ganglia (DRG) also expand significantly after nerve injury3,4. Notably, there are growing interests to determine if macrophages contribute to neuropathic pain development after peripheral nerve injury by interacting with sensory neurons in the DRG5,6,7,8,9,10,11. Moreover, recent studies also implicate the contribution of DRG macrophages in the axonal repair after nerve injury12,13. Another study further suggests that macrophage subpopulations (i.e., CD11b+Ly6Chi and CD11b+Ly6Clow/- cells) may play a different role in the mechanical hypersensitivity14. Therefore, rapidly phenotyping the response of DRG macrophages in the context of nerve injury may help us identify neuroimmune factors contributing to neuropathic pain.
Conventionally, the protocol to isolate macrophages in the DRG involves multiple steps including enzymatic digestion15,16. The technique is often time consuming and can be costly for large-scale experiments. Although mild digestion with collagenase type II (4 mg/mL) and dispase type II (4.7 mg/mL) for 20 min was recommended previously15, it is conceivable that cells after the exposure to this enzyme are prone to cell damage or cell death, which may lead to low yield. In addition, the difference in the quality of enzymes from batch to batch may further impact the efficiency of this process. More importantly, macrophages exposed to the enzyme digestion might be undesirably stimulated and thus can be very different from the in-vivo status. The changes may potentially complicate the outcome of the functional study.
Here we describe an enzyme-free protocol to rapidly isolate DRG macrophages at 4 &#176;C using mechanical dissociation. The samples are kept on ice to limit cellular stress. As a result, our approach provides an advantage to maintain consistency of the isolation, and the isolated cells are presumably healthier and less stimulated. We further present the evidence to validate the quality of the isolated cells with Fluorescence-activated Cell Sorting (FACS) analysis.

<table>
	<tbody>
		<tr>
			<td>AP20187</td>
			<td>Clontech</td>
			<td>635058</td>
			<td></td>
		</tr>
		<tr>
			<td>a-mouse CX3CR1-APC antibody</td>
			<td>Biolegend</td>
			<td>149007</td>
			<td></td>
		</tr>
		<tr>
			<td>Avertin</td>
			<td>Sigma</td>
			<td>T48402</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell strainer (70 mm nylon)</td>
			<td>Falcon</td>
			<td>352350</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf</td>
			<td>5810R</td>
			<td></td>
		</tr>
		<tr>
			<td>Dounce tissue homogenizer</td>
			<td>Wheaton</td>
			<td>357538 (1ml)</td>
			<td></td>
		</tr>
		<tr>
			<td>FACS tubes (5ml)</td>
			<td>Falcon</td>
			<td>352052</td>
			<td></td>
		</tr>
		<tr>
			<td>Friedman-Pearson Rongeur</td>
			<td>FST</td>
			<td>16121-14</td>
			<td></td>
		</tr>
		<tr>
			<td>HBSS (10x, Ca++/Mg++-free)</td>
			<td>Gibco</td>
			<td>14185-052</td>
			<td></td>
		</tr>
		<tr>
			<td>Noyes Spring Scissor</td>
			<td>FST</td>
			<td>15012-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Percoll</td>
			<td>Sigma</td>
			<td>P4937-500ml</td>
			<td></td>
		</tr>
		<tr>
			<td>Propidium iodide</td>
			<td>Sigma</td>
			<td>P4864-10ml</td>
			<td></td>
		</tr>
	</tbody>
</table>

rapid isolation of dorsal root ganglion macrophages

There are growing interests to study the molecular and cellular interactions among immune cells and sensory neurons in the dorsal root ganglia after peripheral nerve injury. Peripheral monocytic cells, including macrophages, are known to respond to a tissue injury through phagocytosis, antigen presentation, and cytokine release. Emerging evidence has implicated the contribution of dorsal root ganglia macrophages to neuropathic pain development and axonal repair in the context of nerve injury. Rapidly phenotyping (or &#8220;rapid isolation of&#8221;) the response of dorsal root ganglia macrophages in the context of nerve injury is desired to identify the unknown neuroimmune factors. Here we demonstrate how our lab rapidly and effectively isolates macrophages from the dorsal root ganglia using an enzyme-free mechanical dissociation protocol. The samples are kept on ice throughout to limit cellular stress. This protocol is far less time consuming compared to the standard enzymatic protocol and has been routinely used for our Fluorescence-activated Cell Sorting analysis.

To validate the isolated cells, we first chose the Macrophage Fas-Induced Apoptosis (MAFIA) transgenic mice17. This line expresses a drug-inducible FK506-binding protein (FKBP)-Fas suicide fusion gene and green fluorescent protein (eGFP) under the control of the promoter of CSF1 receptor (CSF1R), which is specifically expressed in both macrophages and microglia. Systemic injection of FK-binding protein dimerizer, AP20187 (AP), induces the apoptosis of the cells expressing the transgene. The expres...

Watch this Scientific Journal Video about Rapid Isolation of Dorsal Root Ganglion Macrophages at JoVE.com

Rapid Isolation of Dorsal Root Ganglion Macrophages (Video) | JoVE

Here we present a mechanical dissociation protocol to rapidly isolate macrophages from the dorsal root ganglion for phenotyping and functional analysis.

Rapid Isolation of Dorsal Root Ganglion Macrophages

There are growing interests to study the molecular and cellular interactions among immune cells and sensory neurons in the dorsal root ganglia after ...

Research

JoVE Journal

Neuroscience

Genetic Study of Axon Regeneration with Cultured Adult Dorsal Root Ganglion Neurons

Genetic Study of Axon Regeneration with Cultured Adult Dorsal Root Ganglion Neurons (Video) | JoVE

It is well known that mature neurons in the central nervous system (CNS) cannot regenerate their axons after injuries due to diminished intrinsic ability ...

In Vitro Modeling of Cancerous Neural Invasion: The Dorsal Root Ganglion Model

In Vitro Modeling of Cancerous Neural Invasion: The Dorsal Root Ganglion Model (Video) | JoVE

One way that solid tumors disseminate is through neural invasion. This route is well-known in cancers of the head and neck, prostate, and pancreas. These ...

An Approach to Enhance Alignment and Myelination of Dorsal Root Ganglion Neurons

An Approach to Enhance Alignment and Myelination of Dorsal Root Ganglion Neurons (Video) | JoVE

Axon regeneration is a chaotic process due largely to unorganized axon alignment. Therefore, in order for a sufficient number of regenerated axons to ...

Hydraulic Extrusion of the Spinal Cord and Isolation of Dorsal Root Ganglia in Rodents

Hydraulic Extrusion of the Spinal Cord and Isolation of Dorsal Root Ganglia in Rodents (Video) | JoVE

Traditionally, the spinal cord is isolated by laminectomy, i.e. by breaking open the spinal vertebrae one at a time. This is both time consuming and may ...

Dorsal Root Ganglion Injection and Dorsal Root Crush Injury as a Model for Sensory Axon Regeneration

Dorsal Root Ganglion Injection and Dorsal Root Crush Injury as a Model for Sensory Axon Regeneration (Video) | JoVE

Achieving axon regeneration after nervous system injury is a challenging task. As different parts of the central nervous system (CNS) differ from each ...

Laminotomy for Lumbar Dorsal Root Ganglion Access and Injection in Swine

Laminotomy for Lumbar Dorsal Root Ganglion Access and Injection in Swine (Video) | JoVE

Dorsal root ganglia (DRG) are anatomically well defined structures that contain all primary sensory neurons below the head. This fact makes DRG attractive ...

Analysis of Immune Cells in Single Sciatic Nerves and Dorsal Root Ganglion from a Single Mouse Using Flow Cytometry

Analysis of Immune Cells in Single Sciatic Nerves and Dorsal Root Ganglion from a Single Mouse Using Flow Cytometry (Video) | JoVE

Nerve-resident immune cells in the peripheral nervous system (PNS) are essential to maintaining neuronal integrity in a healthy nerve. The immune cells of ...

Dorsal Root Ganglia Isolation and Primary Culture to Study Neurotransmitter Release

Dorsal Root Ganglia Isolation and Primary Culture to Study Neurotransmitter Release (Video) | JoVE

Dorsal root ganglia (DRG) contain cell bodies of sensory neurons. This type of neuron is pseudo-unipolar, with two axons that innervate peripheral ...

Investigating Mammalian Axon Regeneration: In Vivo Electroporation of Adult Mouse Dorsal Root Ganglion

Investigating Mammalian Axon Regeneration: In Vivo Electroporation of Adult Mouse Dorsal Root Ganglion (Video) | JoVE

Electroporation is an essential non-viral gene transfection approach to introduce DNA plasmids or small RNA molecules into cells. A sensory neuron in the ...

Use of In Vivo Single-fiber Recording and Intact Dorsal Root Ganglion with Attached Sciatic Nerve to Examine the Mechanism of Conduction Failure

Use of In Vivo Single-fiber Recording and Intact Dorsal Root Ganglion with Attached Sciatic Nerve to Examine the Mechanism of Conduction Failure (Video) | JoVE

Single-fiber recording has been a classical and effective electrophysiological technique over the last few decades because of its specific application for ...