The authors thank Olga Sharma, Theresa Hundt, and the staff of the DZNE microscopy and animal facilities for technical support.

All procedures including animals were performed with approval of the animal protection committee of North Rhine-Westphalia State Environment Agency (LANUV). Animals were housed and cared for according to standard conditions with a 12 h light/dark cycle and free access to food and water.
1. Animal Model
<ol>
	<li>Intercross hemizygous Tg(Gfap-luc+/-) mice with hemizygous Tg(M83+/-) mice to generate hemizygous bigenic Tg(M83+/-:Gfap-luc+/...

<ol>
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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=Lewy+bodies+in+grafted+neurons+in+subjects+with+Parkinson's+disease+suggest+host-to-graft+disease+propagation.">Lewy bodies in grafted neurons in subjects with Parkinson's disease suggest host-to-graft disease propagation.</a> Nat Med. 14 (5), 501-503 (2008).</li><li>Hansen, 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=alpha-Synuclein+propagates+from+mouse+brain+to+grafted+dopaminergic+neurons+and+seeds+aggregation+in+cultured+human+cells.">alpha-Synuclein propagates from mouse brain to grafted dopaminergic neurons and seeds aggregation in cultured human cells.</a> J Clin Invest. 121 (2), 715-725 (2011).</li><li>Masuda-Suzukake, 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=Prion-like+spreading+of+pathological+alpha-synuclein+in+brain.">Prion-like spreading of pathological alpha-synuclein in brain.</a> Brain. 136 (4), 1128-1138 (2013).</li><li>Holmqvist, 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=Direct+evidence+of+Parkinson+pathology+spread+from+the+gastrointestinal+tract+to+the+brain+in+rats.">Direct evidence of Parkinson pathology spread from the gastrointestinal tract to the brain in rats.</a> Acta Neuropathol. 128 (6), 805-820 (2014).</li><li>Luk, K. 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=Pathological+alpha-synuclein+transmission+initiates+Parkinson-like+neurodegeneration+in+nontransgenic+mice.">Pathological alpha-synuclein transmission initiates Parkinson-like neurodegeneration in nontransgenic mice.</a> Science. 338 (6109), 949-953 (2012).</li><li>Sacino, A. N., 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=Induction+of+CNS+alpha-synuclein+pathology+by+fibrillar+and+non-amyloidogenic+recombinant+alpha-synuclein.">Induction of CNS alpha-synuclein pathology by fibrillar and non-amyloidogenic recombinant alpha-synuclein.</a> Acta Neuropathol Commun. 1, 38 (2013).</li><li>Sacino, A. 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Peripheral injection of alpha-synuclein fibrils into the peritoneum of Tg(M83+/-:Gfap-luc+/-) mice represents a facile method to induce neurologic disease accompanied by neuroinflammation to recapitulate important characteristics of synucleinopathies. Similarly, tongue injection represents another route for neuroinvasion by alpha-synuclein prionoids in transgenic mice but is less efficient. We chose to terminate our experiments at 420 days after injection and we cannot exclude the possibili...

There is growing evidence that alpha-synuclein has characteristics that are similar to those of the prion protein, particularly in its capacity to self-seed and propagate misfolding between cells and along neuronal pathways. This property of alpha-synuclein is also referred to as &#39;prion-like&#39; or &#39;prionoid&#39;, and is supported by observations in transplantation experiments, which suggest the transmissibility of misfolded alpha-synuclein from diseased neurons to newly transplanted healthy neurons1,2,3,4. Also direct injection of misfolded alpha-synuclein into the brain or the periphery, e.g. the hindlimb muscle or intestinal wall, results in a spread of alpha-synuclein pathology to distal parts of the CNS5,6,7,8,9,10. We analyzed transmission of alpha-synuclein prionoids via peripheral routes in more detail and addressed the question whether misfolded alpha-synuclein may neuroinvade the CNS after a single intraglossal or intraperitoneal injection, a feature that previously had been shown for prions but not for misfolded alpha-synuclein. After injection of prions into the tongue, neuroinvasion of the CNS is achieved via propagation along the hypoglossal nerve of the tongue that leads to the nucleus of the hypoglossal nerve, which is located in the brain stem11. As a mouse model we chose Tg(M83+/-:Gfap-luc+/-) mice that overexpress the A53T mutant of human alpha-synuclein from the prion promoter, and firefly luciferase under control of a Gfap promoter to monitor astrocytic activation by bioluminescence, as previously shown in the brain of prion-infected mice12. In our hands bigenic Tg(M83+/-:Gfap-luc+/-) mice did not develop disease until 23 months of age as has been shown by others13. A single injection of human alpha-synuclein fibrils via the intraglossal or intraperitoneal route induced neurologic disease with pathology in the brains and spinal cords of Tg(M83+/-:Gfap-luc+/-) mice supporting the hypothesis that alpha-synuclein prionoids share important characteristics with prions14.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>anti-actin antibody</td>
			<td>Merck Millipore</td>
			<td>MAB1501</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-alpha-synuclein, phospho S129 antibody [pSyn#64]</td>
			<td>Wako</td>
			<td>015-25191</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-alpha-synuclein, phospho S129 antibody [EP1536Y]</td>
			<td>Abcam</td>
			<td>ab51253</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-GFAP antibody</td>
			<td>Dako</td>
			<td>Z0334 01</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-IBA-1 antibody</td>
			<td>Wako</td>
			<td>019-19741</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-Sequestosome-1 (p62) antibody</td>
			<td>Proteintech</td>
			<td>18420-1-AP</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-ubiquitin antibody [Ubi-1]</td>
			<td>Merck Millipore</td>
			<td>MAB1510</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate-buffered saline (PBS)</td>
			<td>Invitrogen</td>
			<td>14190169</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine&#160;</td>
			<td>Ratiopharm</td>
			<td></td>
			<td>100 mg/kg</td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Ratiopharm</td>
			<td></td>
			<td>10 mg/kg</td>
		</tr>
		<tr>
			<td>27-gauge syringe</td>
			<td>VWR</td>
			<td>613-4900</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane&#160;</td>
			<td>Piramal Healthcare</td>
			<td>PZN&#160; 4831850</td>
			<td></td>
		</tr>
		<tr>
			<td>Depilatory cream</td>
			<td>Veet</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Secureline lab marker&#160;</td>
			<td>Neolab</td>
			<td>25040</td>
			<td></td>
		</tr>
		<tr>
			<td>D-luciferin potassium salt</td>
			<td>Acris</td>
			<td>LK10000</td>
			<td>30 mg/mL stock solution</td>
		</tr>
		<tr>
			<td>Thermomixer</td>
			<td>Eppendorf</td>
			<td>5776671</td>
			<td></td>
		</tr>
		<tr>
			<td>Sonopuls Mini20 sonicator</td>
			<td>Bandelin</td>
			<td>3648</td>
			<td></td>
		</tr>
		<tr>
			<td>IVIS Lumina II imaging system</td>
			<td>PerkinElmer</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Living Image 3.0 Software</td>
			<td>PerkinElmer</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tg(M83+/-) mice or B6;C3-Tg(Prnp-SNCA*A53T)83Vle/J mice</td>
			<td>The Jackson Laboratory</td>
			<td>004479</td>
			<td></td>
		</tr>
		<tr>
			<td>Standard pattern forceps</td>
			<td>Fine Science Tools</td>
			<td>11000-16</td>
			<td></td>
		</tr>
		<tr>
			<td>Narrow pattern forceps</td>
			<td>Fine Science Tools</td>
			<td>11002-12</td>
			<td></td>
		</tr>
		<tr>
			<td>N-laurylasarcosyl</td>
			<td>Sigma</td>
			<td>L5125-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Optima Max-XP ultracentrifuge&#160;</td>
			<td>Beckman Coulter</td>
			<td></td>
			<td>TLA-110 rotor&#160;</td>
		</tr>
		<tr>
			<td>Thickwall polycarbonate tubes</td>
			<td>Beckman Coulter</td>
			<td>362305</td>
			<td></td>
		</tr>
		<tr>
			<td>NuPAG Novex 4-12% Bis-Tris Midi Protein Gels</td>
			<td>Thermo Fisher Scientific</td>
			<td>WG1401BOX</td>
			<td></td>
		</tr>
		<tr>
			<td>HRP conjugated antibody</td>
			<td>Cayman</td>
			<td>Cay10004301-1</td>
			<td></td>
		</tr>
		<tr>
			<td>IR Dye 680 conjugated antibody&#160;</td>
			<td>LI-COR Biosciences</td>
			<td>926-68070</td>
			<td></td>
		</tr>
		<tr>
			<td>SuperSignal West Dura Extended Duration Substrate</td>
			<td>Thermo Fisher Scientific</td>
			<td>34075</td>
			<td></td>
		</tr>
		<tr>
			<td>Stella 3200 imaging system</td>
			<td>Raytest</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Odyssey infrared imaging system&#160;</td>
			<td>LI-COR Biosciences</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Tween 20&#160;</td>
			<td>MP Biomedicals</td>
			<td>TWEEN201</td>
			<td></td>
		</tr>
		<tr>
			<td>Triton X-100</td>
			<td>Sigma</td>
			<td>SA/T8787</td>
			<td></td>
		</tr>
		<tr>
			<td>Immobilon-FL PVDF membrane</td>
			<td>Merck Millipore</td>
			<td>IPFL00010</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylol</td>
			<td>Sigma</td>
			<td>Roth</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrogen peroxide</td>
			<td>Sigma</td>
			<td>SA/00216763/000500</td>
			<td>working solution 3%</td>
		</tr>
		<tr>
			<td>Bovine serum albumine (BSA)&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>A3294-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat serum</td>
			<td>Thermo Fisher Scientific</td>
			<td>PCN5000</td>
			<td></td>
		</tr>
		<tr>
			<td>4,6-diamidino-2-phenylindole (DAPI)</td>
			<td>Thermo Fisher Scientific</td>
			<td>D1306</td>
			<td>working dilution 1:50,000</td>
		</tr>
		<tr>
			<td>Fluoromount media&#160;</td>
			<td>Omnilab</td>
			<td>SA/F4680/000025</td>
			<td></td>
		</tr>
		<tr>
			<td>LSM700 confocal laser scanning microscope</td>
			<td>Carl Zeiss</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>HALT protease and phosphatase inhibitors</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>10516495</td>
			<td></td>
		</tr>
		<tr>
			<td>Precellys 24-Dual homogenizer&#160;</td>
			<td>Peqlab</td>
			<td>91-PCS24D</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 conjugated antibody</td>
			<td>Thermo Fisher Scientific</td>
			<td>A31619</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa Fluor 594 conjugated antibody</td>
			<td>Thermo Fisher Scientific</td>
			<td>A11005</td>
			<td></td>
		</tr>
		<tr>
			<td>Pierce&#160;BCA&#160;Protein&#160;Assay&#160;Kit</td>
			<td>Thermo Fisher Scientific</td>
			<td>10741395</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtome RM2255</td>
			<td>Leica</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>LSM700 confocal laser scanning microscope</td>
			<td>Carl Zeiss</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

bioluminescence imaging of neuroinflammation in transgenic mice after peripheral inoculation of alpha-synuclein fibrils

To study the prion-like behavior of misfolded alpha-synuclein, mouse models are needed that allow fast and simple transmission of alpha-synuclein prionoids, which cause neuropathology within the central nervous system (CNS). Here we describe that intraglossal or intraperitoneal injection of alpha-synuclein fibrils into bigenic Tg(M83+/-:Gfap-luc+/-) mice, which overexpress human alpha-synuclein with the A53T mutation from the prion protein promoter and firefly luciferase from the promoter for glial fibrillary acidic protein (Gfap), is sufficient to induce neuropathologic disease. In comparison to homozygous Tg(M83+/+) mice that develop severe neurologic symptoms beginning at an age of 8 months, heterozygous Tg(M83+/-:Gfap-luc+/-) animals remain free of spontaneous disease until they reach an age of 22 months. Interestingly, injection of alpha-synuclein fibrils via the intraperitoneal route induced neurologic disease with paralysis in four of five Tg(M83+/-:Gfap-luc+/-) mice with a median incubation time of 229 &#177;17 days. Diseased animals showed severe deposits of phosphorylated alpha-synuclein in their brains and spinal cords. Accumulations of alpha-synuclein were sarkosyl-insoluble and colocalized with ubiquitin and p62, and were accompanied by an inflammatory response resulting in astrocytic gliosis and microgliosis. Surprisingly, inoculation of alpha-synuclein fibrils into the tongue was less effective in causing disease with only one of five injected animals showing alpha-synuclein pathology after 285 days. Our findings show that inoculation via the intraglossal route and more so via the intraperitoneal route is suitable to induce neurologic illness with relevant hallmarks of synucleinopathies in Tg(M83+/-:Gfap-luc+/-) mice. This provides a new model for studying prion-like pathogenesis induced by alpha-synuclein prionoids in greater detail.

Peripheral injection of alpha-synuclein prionoids via the tongue or the peritoneum induced neuropathology in the CNS of bigenic Tg(M83+/-:Gfap-luc+/-) mice (Table 1 and Figure 1). After a single intraperitoneal injection with alpha-synuclein fibrils, four of five mice developed neurologic disease with a median incubation time of 229 &#177;17 days. Surprisingly, only one of five mice developed CNS disease after intraglossal i...

Watch this Scientific Journal Video about Bioluminescence Imaging of Neuroinflammation in Transgenic Mice After Peripheral Inoculation of Alpha-Synuclein Fibrils at JoVE.com

Bioluminescence Imaging of Neuroinflammation in Transgenic Mice After Peripheral Inoculation of Alpha-Synuclein Fibrils

Peripheral injection of alpha-synuclein fibrils into the peritoneum or tongue of Tg(M83+/-:Gfap-luc+/-) mice, which express human alpha-synuclein with the familial A53T mutation and firefly luciferase, can induce neuropathology, including neuroinflammation, in their central nervous system.

To study the prion-like behavior of misfolded alpha-synuclein, mouse models are needed that allow fast and simple transmission of alpha-synuclein ...

The overall goal of this bioluminescence imaging method is to quantify neuroinflammation in the central nervous system of a Parkinson's disease mouse model after peripheral injection of alpha-synuclein fibrils. This method can help determine when and to what degree neuroinflammation occurs in mouse models of neurodegenerative diseases. The main advantage of this technique is the neuroinflammation can be noninvasively and repeatedly monitored until any mice develop neurologic illness.The implication of this technique is 10th hour diagnosis of neurological disease because an increase in bioluminescence due to nerve inflammation not only accompanies but often preceded neurological disease. Begin by properly anesthetizing the animal for surgery. Administer a toe-pinch and confirm that the animal does not withdraw the limb to indicate a surgical plane of anesthesia.Apply ophthalmic ointment to prevent dryness while under anesthesia. Use adhesive tape to carefully fix the animal onto a heating plate in a dorsal recumbent position with the head towards the investigator. Then fill a 27 gauge disposable hypodermic syringe with five microliters of sonicated alpha-synuclein fibrils.Next, use a pair of blunt nosed thumb forceps to hold the animal's mouth open and use the smaller pair of forceps to carefully pull out the tongue to make the underside of the tongue accessible for injection. Insert the needle of the syringe into the right or left bottom side of the tongue in proximity to the hypoglossal nerve. After five seconds, slowly inject the inoculum.Allow the needle to remain in place for a further five seconds to ensure that the inoculum penetrates the tissue, and then carefully withdraw the needle. After the injection, release the animal and allow it to remain on the heating plate under constant monitoring until complete recovery. For intraperitoneal injections, briefly narcotize the animals in an anesthesia chamber with isoflurane.Again, pinch the animal's toe and confirm that it does not withdraw its hindlimb to ensure proper anesthesia. Fill a 27 gauge disposable hypodermic syringe with 50 microliters of sonicated alpha-synucelin fibirls, or PBS. Hold the animal in a dorsal position with the head facing away from the investigator and downward at approximately 45 degrees.Directly inject into the peritoneum of the mouse without penetrating the small intestine or cecum located behind the abdominal wall. Monitor animals until they have recovered from the anesthesia. Prior to imaging, shave and depilate the heads of isoflurane anesthetized mice.Color the ears in black with a non-irritating marker to block unspecific bioluminescence. Weigh the animals prior to injection. Then calculate the exact volume of D-Luciferin for injection at 150 milligrams per kilogram of body weight.Intraperitoneally inject the calculated volume of D-Luciferin, and then return each animal to the anesthesia chamber. Start the imaging software. After the imaging system has reached its operating temperature, initialize the system by clicking on the Initialize button in the control panel.Then select the buttons Luminescent and Photograph. Set the exposure time to 60 seconds, the Binning to medium, the F/Stop to one, and the EM gain to off. Select Block and then Open.And then under the tab subject height, choose 1.50 from the dropdown menu. Ten minutes after injection with D-Luciferin, place the animals onto the heating plate in the imaging chamber, and ensure that their muscles are correctly placed in the anesthesia outlet. Switch the isoflurane flow from the inhalation chamber to the imaging chamber, and properly close the door of the imaging chamber.Click on the acquire button to measure the bioluminescence, which takes 60 seconds. Stop the isoflurane flow, and then return the animals to their cages. Use the imaging software to quantify bioluminescence by opening the tool palette menu and selecting ROI Tools.Under type, select Measurement ROI. Within ROI Tools, click the circle tool and select the number of ROIs to draw from the pull-down menu. Ideally three for three mice.In the image, right-click each ROI and under properties, adjust the width and height to 1.25 centimeters. Position each ROI over the brain area that is quantified. In the upper left of the image, set the units panel to radiance in photons.Then open the tool palette menu. Select image adjust and adjust the minimum and the maximum of the color scale. For instance, from 200, 000 to one million.Lastly, under file, click save to save the data. As shown here, after intraperitoneal injection with alpha-synuclein fibrils, four of the five A53T synuclein GFAP luciferous reporter transgenic mice developed neurologic disease within 229 days as indicated by the purple squares. However, only one of five interglossally injected mice developed neurologic illness within 285 days as indicated by the green circles.Bioluminescence imaging revealed that the transgenic mice emitted elevated bioluminescence from their brains and spinal cords, shortly before they developed signs of neurologic disease. This bioluminescence was more pronounced after intraperitoneal injection and absent after PBS injection suggesting an absence of astrocytic gliosis. This figure shows the bioluminescence in the brains of transgenic mice over time after intraperitoneal injection of alpha-synuclein fibrils.As shown by the blue, green, brown, and orange circles. Increased levels of bioluminescence above a threshold of 2 million photons per second per square centimeter per steradian were observed some weeks before these four individual mice developed neurologic signs of disease. One of five animals also showed elevated levels of bioluminescence shortly before it died 285 days after intraglossal injection with alpha-synuclein fibrils.In contrast, for healthy PBS injected control mice, and one animal that did not develop disease after intraperitoneal injection, with alpha-synuclein fibrils indicated by the red circles, the bioluminescence signal remained below threshold within the period of observation. Immunofluorescence staining of brain sections of diseased animals with antibodies against GFAP and Iba1 confirmed neuroinflammation with microgliosis and reactive astrocytes in regions with alpha-synuclein deposits. Healthy animals that did not accumulate deposits of alpha-synuclein showed little staining for GFAP and Iba1.Once mastered, this technique can be done in less than one hour if it's performed properly. After its development, this technique paved the way for researchers in the field of neurodegeneration to noninvasively explore neuroinflammation in the central nervous system of mice. After watching this video, you should have a good understanding of how to peripherally inject mice with alpha-synuclein fibrils and how to perform bioluminescence imaging to monitor CNS neuroinflammation.The overall goal of the procedure is to peripherally induce neurologic illness by intraglossal or intraperitoneal injection with alpha-synuclein fibrils and to noninvasively image the induction of neuroinflammation over time.

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8.5K vistas.  German Center for Neurodegenerative Diseases (DZNE). The overall goal of this bioluminescence imaging method is to quantify neuroinflammation in the central nervous system of a Parkinson's disease mouse model after peripheral injection of alpha-synuclein fibrils. This method can help determine when and to what degree neuroinflammation occurs in mouse models of neurodegenerative diseases. The main advantage of this technique is the neuroinflammation can be noninvasively and repeatedly monitored until any mice develop neurologic illness.Th...