Name: development of an alpha-synuclein based rat model for parkinson's disease via stereotactic injection of a recombinant adeno-associated viral vector
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The authors thank Joris Van Asselberghs and Ann Van Santvoort for their excellent technical assistance. Research was funded by the IWT-Vlaanderen (IWT SBO/80020), the FWO Vlaanderen (G.0768.10), by the EC-FP6 program &#39;DiMI&#39; (LSHB-CT-2005-512146), the FP7 RTD project MEFOPA (HEALTH-2009-241791), the FP7 program &#39;INMiND&#39; (HEALTH-F2-2011-278850), the KU Leuven (IOF-KP/07/001, OT/08/052A, IMIR PF/10/017), and the MJFox Foundation (Target validation 2010). A. Van der Perren and C. Casteels are&#160;a postdoctoral fellows of the Flemish Fund of Scientific Research. K. Van Laere is a senior clinical fellow of the Flemish Fund of Scientific Research.

All animal experiments are carried out in accordance with the European Communities Council Directive of 24 November 1986 (86/609/EEC) and approved by the Bioethical Committee of the University of Leuven (Belgium).
1. Recombinant AAV Production and Purification
Note: rAAV vector production and purification was performed by the Leuven Viral Vector Core (LVVC) as previously described17.
<ol>
	<li>Briefly, transfect subconfluent low (&#60;50) passage adherent HEK 293T cells using a 25kD linear poly...

<ol>
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There are several critical steps within the protocol. The vector titer as well as the vector purity directly influences the phenotypic outcome of the model. Excessive vector titers or insufficiently purified vector batches may result in non-specific toxicity. Therefore, the use of high quality vector batches and appropriate control vectors is indispensable. Further, the exact positioning of the rat&#39;s head in the stereotaxic frame and the accurate determination of the coordinates is essential in targeting the substant...

To study the pathophysiology of PD and to develop novel therapeutic strategies, there is an urgent need for animal models that closely resemble the neuropathology, physiology and motor symptoms of human PD. The higher the predictive value, the better we can translate new therapies from animal models to patients.
The discovery of alpha-synuclein (&#945;-SYN) as the first PARK gene in 1997 led to the development of the first genetic PD models. Many transgenic mice overexpressing human wild-type (WT) or mutant (A30P, A53T) &#945;-SYN have been generated over the last decade. The levels of &#945;-SYN overexpression have proven to be crucial in the development of the pathology. Also the mouse strain, the presence or absence of endogenous &#945;-SYN and whether the full length or a truncated form is expressed, plays a role (detailed review by Magen and Chesselet1). Overexpression of both WT and several clinical mutants of human &#945;-SYN in transgenic mice induces pathological accumulation of &#945;-SYN and neuronal dysfunction2-6. However, until now most transgenic &#945;-SYN mouse models failed to display clear dopaminergic cell loss and dopamine-dependent behavioral deficits.
This hurdle was overcome by direct targeting of the substantia nigra (SN) with viral vectors overexpressing &#945;-SYN. Viral vectors are derived from viruses that can easily infect cells, introduce genetic material into their host genome and force the host cell to replicate the viral genome in order to produce new virus particles. Viruses can be engineered to non-replicating viral vectors that retain their ability to enter cells and introduce genes. By deleting parts of the viral genome and replacing them by the genes of interest, application of the vector will result in a single round infection without replication in the host cell, generally designated as &#39;transduction&#39;. Viral vectors can be used for both overexpression and gene silencing. The expressed transgene can be a reporter protein (e.g. green fluorescent protein or firefly luciferase)7, a therapeutic protein for gene therapy applications8-10 or, as we will focus on in this paper, a disease-related protein used for disease modeling11-14.
Viral vector-mediated gene delivery provides an alternative way to express transgenes in the CNS with several advantages. Using local transgene delivery, specific brain regions can be targeted. Further, transgene expression can be induced during adulthood decreasing the risk of compensatory mechanisms during development. Also, models can be created in different species and strains. And finally, different transgenes can easily be combined. Using viral vectors, high transgene expression levels can be achieved, which might be crucial since the disease onset and severity frequently depend on the level of overexpression.
Several vector systems based on different viruses have been developed. The choice of the vector system depends on the size of the gene of interest, the required duration of gene expression, the target cell and biosafety issues. For stable gene transfer in the brain, lentiviral (LV) and recombinant adeno-associated viral (rAAV) vectors are now considered the vector systems of choice since they lead to efficient and long-term gene expression in the rodent brain. For specific targeting of the dopaminergic neurons (DN) of the SN, rAAV vectors have gradually outcompeted LV vectors because of their higher titers and transduction efficiency of DN.
The best &#945;-SYN based rodent models currently available have been developed from a combined approach using newer AAV serotypes (rAAV 1, 5, 6, 7, 8) and optimized vector constructs, titers, and purity15,16. The vector titer as well as the vector purity directly influences the phenotypic outcome of the model. Excessive vector titers or insufficiently purified vector batches may result in non-specific toxicity. Therefore, appropriate control vectors are indispensable. Considerable time investment in the viral vector production, upscaling, and purification procedures have also proven essential to obtain reproducible and high quality vector batches.

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	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:391px;">Female 8 weeks old Wistar rats</td>
			<td style="width:227px;">Janvier</td>
			<td style="width:187px;">/</td>
			<td style="width:681px;">200-250 g</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Ketamine (Nimatek)</td>
			<td>Eurovet animal health</td>
			<td>804132</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Medetomidine (Dormitor)</td>
			<td>Orion-Pharma/ Janssen Animal Health</td>
			<td>1070-499</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">&#160;Local anesthetic for scalp and ears: Xyloca&#239;ne 2% gel</td>
			<td>Astrazeneca</td>
			<td>0137-547</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Terramycine</td>
			<td>Pfizer</td>
			<td>0132-472</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Bupr&#233;norphine (Vetergesic)</td>
			<td>Ecuphar</td>
			<td>2623-627</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Jodium 1% isopropanol</td>
			<td>VWR</td>
			<td>0484-0100</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">stereotactic head frame</td>
			<td>Stoeling</td>
			<td>/</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Hamilton Syringe (30 gauge -20mm -pst 2)</td>
			<td>Hamilton/ Filter Service</td>
			<td>7803-07</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">atipamezole (Antisedan)</td>
			<td>Orion-Pharma/Elanco</td>
			<td>1300-185</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">rAAV A53T &#945;-SYN vector</td>
			<td>LVVC, KU Leuven</td>
			<td>/</td>
			<td>https://gbiomed.kuleuven.be/english/research/50000715/laboratory-of-molecular-virology-and-gene-therapy/lvvc/</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">sodium pentobarbital (Nembutal)</td>
			<td>Ceva Sant&#233;</td>
			<td>0059-444</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">microtome</td>
			<td>Microm</td>
			<td>HM650</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">rabbit polyclonal synuclein Ab</td>
			<td>Chemicon</td>
			<td>5038</td>
			<td>1:5000</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">rabbit polyclonal TH Ab</td>
			<td>Chemicon</td>
			<td>152</td>
			<td>1:1000</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Lutetium oxyorthosilicate detector-based FOCUS 220 tomograph</td>
			<td>Siemens/ Concorde Microsystems</td>
			<td>/</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">radioligand: 18F-FECT</td>
			<td>In house</td>
			<td>/</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">L-dopa: Prolopa 125</td>
			<td>Roche</td>
			<td></td>
			<td>6mg/kg i.p.</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DMEM, Glutamax</td>
			<td>Life Technologies</td>
			<td>N&#176; 31331-093</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Foetal bovine serum</td>
			<td>Life Technologies</td>
			<td>N&#176; 10270-106</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">25 kD linear polyethylenimine (PEI)</td>
			<td>Polysciences</td>
			<td>/</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">OptiPrep Density Gradient Medium: Iodixanol</td>
			<td>Sigma</td>
			<td>D1556-250ML</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Optimen</td>
			<td>Life Technologies</td>
			<td>N&#176; 51985-026</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Paxinos 1 watston steretactic atlas, fourth Edition</td>
			<td>Elsevier</td>
			<td>/</td>
			<td></td>
		</tr>
	</tbody>
</table>

development of an alpha-synuclein based rat model for parkinson's disease via stereotactic injection of a recombinant adeno-associated viral vector

In order to study the molecular pathways of Parkinson&#39;s disease (PD) and to develop novel therapeutic strategies, scientific investigators rely on animal models. The identification of PD-associated genes has led to the development of genetic PD models. Most transgenic &#945;-SYN mouse models develop gradual &#945;-SYN pathology but fail to display clear dopaminergic cell loss and dopamine-dependent behavioral deficits. This hurdle was overcome by direct targeting of the substantia nigra with viral vectors overexpressing PD-associated genes. Local gene delivery using viral vectors provides an attractive way to express transgenes in the central nervous system. Specific brain regions can be targeted (e.g. the substantia nigra), expression can be induced in the adult setting and high expression levels can be achieved. Further, different vector systems based on various viruses can be used. The protocol outlines all crucial steps to perform a viral vector injection in the substantia nigra of the rat to develop a viral vector-based alpha-synuclein animal model for Parkinson&#39;s disease.

The overall scheme of the experiment is depicted in Figure 1
rAAV 2/7-mediated overexpression of A53T &#945;-SYN induces dopamine-dependent motor deficits. 
To examine whether the level of &#945;-SYN overexpression is sufficient to induce motor impairments in the rats, we subjected the rats to the cylinder test to evaluate spontaneous forelimb use (Figure 3A). From 3 weeks ...

Watch this Scientific Journal Video about Development of an Alpha-synuclein Based Rat Model for Parkinson's Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector at JoVE.co

Development of an Alpha-synuclein Based Rat Model for Parkinson&#039;s Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector

This manuscript describes how viral vector-mediated local gene delivery provides an attractive way to express transgenes in the central nervous system. The protocol outlines all crucial steps to perform a viral vector injection in the substantia nigra of the rat to develop a viral vector-based animal model for Parkinson's disease.

Development of an Alpha-synuclein Based Rat Model for Parkinson's Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector

In order to study the molecular pathways of Parkinson&#39;s disease (PD) and to develop novel therapeutic strategies, scientific investigators rely on ...

The overall goal of this procedure is to develop a viral vector based animal model for Parkinson's Disease via Stereotactic Injection in the central nervous system. This method can be used to develop normal animal models which allow for pre-clinical drug testing and can be beneficial in studying the molecular mechanism of Parkinson's Disease as well as many other neurodegenerative disorders. The main advantage of this technique is that it can be used for specific targeting of brain regions.High trenching brain expression can be achieved and that it can be used to create animal models in specific animal strains and species. The different final vector systems have been developed. The choice of the vector system depends on the size of the trenching you want to express, the duration of the gene expression, the sounds that you want to target, and bio-safety issues.Demonstrating the procedure will be Annelies Aertgeerts a technician from our laboratory. Begin by properly anesthetizing an eight week old female Wistar rat according to approved protocols. Check that a surgical plane of anesthesia has been achieved by squeezing each paw, and noting an absence of the withdrawal reflex.Next, use a MicroTransponder implanter to place a MicroTransponder on the back of the rat. Check that the MicroTransponder is positioned correctly and that a readout can be obtained. Now cut the hair on the scalp of the rat, and apply local anesthetic to the scalp and ears.Transfer the rat to a laminar flow hood, and perform the rest of the procedure using aseptic technique. Place the rat in the stereotaxic frame, by securing the ear bars, followed by the mouth and nose bar. Cover the body of the rat with a paper blanket to avoid a drop in body temperature.Apply an ocular lubricant to prevent the eyes from drying. Next disinfect the scalp according to approved procedures. One percent iodine in 70%isopropyl is used here.After making a small incision in the mid-line of the scalp, gently scrape away the membranes on the skull, and rinse with saline. After allowing the skull to dry, ensure that bregma and lambda can clearly be seen. Now, fill a 10 micro-liter, 30 gauge 20 milometer microinjection-syringe with recombinant AAV and place it onto the motorized micro-injection pump connected to the stereotaxic instrument.For specific transaction of the Dopaminergic neurons of the substantia nigra, recombinant AV vectors are the first choice because of their high titers and efficiency for transducing Dopaminergic neurons. Test the flow, by releasing a drop of AAV. Dispose of any released AAV in a polyvalent cleaning detergent.Visually check that the head is fixed straight in the head frame. Then check that the skull is flat, by first moving the tip of the needle to bregma and measuring the height at this point, by lowering the tip of the needle in the dorsal-ventral direction until in touches the skull. Repeat the procedure at lambda.After returning the needle to bregma, move the needle in the anterior posterior and medial lateral direction to the stereotaxic coordinates for microinjection. Write down the coordinates. At the site of injection, measure the height of the skull as before, and ensure that it does not differ from more than 0.3mm from the height of bregma.Then carefully drill a two milimeter hole in the skull. Once the hole is drilled, measure the height of the dura to determine the reference from which to apply the dorsal-ventral coordinate. Penetrate the dura using a 26 gauge needle.Absorb any blood with the sterile tissue, and proceed only after all bleeding has stopped. Now slowly lower the needle of the pre-loaded microinjection syringe into the brain to the dorsal-ventral coordinate. And pause for one minute.Then inject three micro-liters of AAV at a rate of 0.25 micro-liters per minute. After the injection, allow the needle to remain in place for another five minutes to prevent back flow along the needle track before slowly removing it. Stitch the scalp using coded braided polyester 3.0 and disinfect the skin with one percent iodine and 70%isopropyl.To loosen the nose and mouth bar, and then the two ear bars, to gently remove the animal from the stereotaxic instrument. At this time administer analgesia, and if required, an anesthesia reversal agent. Then place the rat in a clean cage on a heating plate set to 38 degrees Celsius, and monitor closely until it wakes up.Following surgery, the kinetics of neurodegeneration can be studied in the whole animal using behavioral tests and PET imaging and after sacrifice, using immunohistochemical techniques. The cylinder test to evaluate spontaneous forelimb use, was performed at various time points following microinjection of recombinant AAV expressing A53T Mutation alpha synuclein into the substantia nigra. From three weeks after injection, the significant motor impairment was seen in rats that received the median dose.At four weeks after injection, a 50%decrease in spontaneous contralateral forepaw use was observed. Whereas the control eGFP injected animals showed no asymmetry in forepaw use. Rats that received a higher dose of recombinant AAV 2/7A53T alpha synuclein, showed a more pronounced impairment of forepaw use at 29 days after injection.To prove that the observed motor impairment was dopamine dependent, a single dose of L-doba was administered. When the cylinder test was repeated 45 minutes after L-dopa treatment, a full recovery of the forepaw use in the recombinant AAV 2/7A53T alpha synuclein injected animals, was observed. To follow up the kinetics of nigrostriatal dopaminergic neurodegeneration non-invasively over time, in individual animals, dopamine transported binding was quantified using small-animal positron emission tomography with F-18FECT as the radioligand.DAT binding significantly decreased in the ipsilateral caudate budiman of recombinant AAV 2/7A53T alpha synuclein injected rats over time. After 32 days, a decrease in DAT binding of up to 85%was observed. As the positive control, injection of the neurotoxin 6 OHDA in the SN induced 90%loss of DAT binding within seven days.Brain sections from rats microinjected with recombinant AAV 2/7A53T alpha synuclein over time were immunostained for tyrosine hydroxylase a marker of dopaminergic neurons. This figure demonstrates the progressive loss of dopaminergic neurons over a 29 day period after microinjection. Once mastered, this technique can be done in 45 minutes.While attempting this procedure, it is important to use high quality final vector matches. Following this procedure, other techniques, like non-invasive PET imaging, behavior analysis, and Immunohistochemical analysis can be performed in order to determine the level of neurodegeneration and neuropathology. After watching this video, you should have a good idea of how to perform a viral vector injection into the substantia nigra in order to develop viral vector based animal models for Parkinson's Disease.Don't forget that working with viral vectors can be hazardous, and that precautions such as working under a laminar flow and proper waste decontamination should always be taken following this procedure.

development-an-alpha-synuclein-based-rat-model-for-parkinson-s

Research

JoVE Journal

Medicine

High-Efficiency Transduction of Liver Cancer Cells by Recombinant Adeno-Associated Virus Serotype 3 Vectors

Recombinant vectors based on a non-pathogenic human parvovirus, the adeno-associated virus 2 (AAV2) have been developed, and are currently in use in a number of gene therapy clinical trials. More recently, a number of additional AAV serotypes have also been isolated, which have been shown to exhibit selective tissue-tropism in various small and large animal models1. Of the 10 most commonly used AAV serotypes, AAV3 is by far the least efficient in transducing cells and tissues in vitro as well as in vivo.
However, in our recently published studies, we have documented that AAV3 vectors transduce human liver cancer - hepatoblastoma (HB) and hepatocellular carcinoma (HCC) - cell lines extremely efficiently because AAV3 utilizes human hepatocyte growth factor receptor as a cellular co-receptor for binding and entry in these cells2,3.
In this article, we describe the steps required to achieve high-efficiency transduction of human liver cancer cells by recombinant AAV3 vectors carrying a reporter gene. The use of recombinant AAV3 vectors carrying a therapeutic gene may eventually lead to the potential gene therapy of liver cancers in humans.

In this article, we describe the identification of the adeno-associated virus serotype 3 (AAV3) as the most efficient vector for targeting human liver cancer cells.

Recombinant vectors based on a non-pathogenic human parvovirus, the adeno-associated virus 2 (AAV2) have been developed, and are currently in use in a ...

Development of a Unilaterally-lesioned 6-OHDA Mouse Model of Parkinson's Disease

The unilaterally lesioned 6-hyroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease (PD) has proved to be invaluable in advancing our understanding of the mechanisms underlying parkinsonian symptoms, since it recapitulates the changes in basal ganglia circuitry and pharmacology observed in parkinsonian patients1-4. However, the precise cellular and molecular changes occurring at cortico-striatal synapses of the output pathways within the striatum, which is the major input region of the basal ganglia remain elusive, and this is believed to be site where pathological abnormalities underlying parkinsonian symptoms arise3,5.
In PD, understanding the mechanisms underlying changes in basal ganglia circuitry following degeneration of the nigro-striatal pathway has been greatly advanced by the development of bacterial artificial chromosome (BAC) mice over-expressing green fluorescent proteins driven by promoters specific for the two striatal output pathways (direct pathway: eGFP-D1; indirect pathway: eGFP-D2 and eGFP-A2a)8, allowing them to be studied in isolation. For example, recent studies have suggested that there are pathological changes in synaptic plasticity in parkinsonian mice9,10. However, these studies utilised juvenile mice and acute models of parkinsonism. It is unclear whether the changes described in adult rats with stable 6-OHDA lesions also occur in these models. Other groups have attempted to generate a stable unilaterally-lesioned 6-OHDA adult mouse model of PD by lesioning the medial forebrain bundle (MFB), unfortunately, the mortality rate in this study was extremely high, with only 14% surviving the surgery for 21 days or longer11. More recent studies have generated intra-nigral lesions with both a low mortality rate &gt;80% loss of dopaminergic neurons, however expression of L-DOPA induced dyskinesia11,12,13,14 was variable in these studies. Another well established mouse model of PD is the MPTP-lesioned mouse15. Whilst this model has proven useful in the assessment of potential neuroprotective agents16, it is less suitable for understanding mechanisms underlying symptoms of PD, as this model often fails to induce motor deficits, and shows a wide variability in the extent of lesion17, 18.
Here we have developed a stable unilateral 6-OHDA-lesioned mouse model of PD by direct administration of 6-OHDA into the MFB, which consistently causes &gt;95% loss of striatal dopamine (as measured by HPLC), as well as producing the behavioural imbalances observed in the well characterised unilateral 6-OHDA-lesioned rat model of PD. This newly developed mouse model of PD will prove a valuable tool in understanding the mechanisms underlying generation of parkinsonian symptoms.

Development of a Unilaterally-lesioned 6-OHDA Mouse Model of Parkinson&#039;s Disease

A protocol for performing unilateral 6-OHDA lesions of the medial forebrain bundle in mice is described. This method has a low mortality rate (13.3 %) with 89% of the surviving animals showing &#62;95% loss of striatal dopamine and 90.63&#177;-4.02 % ipsiversive rotational bias towards the side of the lesion.

The unilaterally lesioned 6-hyroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease (PD) has proved to be invaluable in advancing our ...

MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease

MALDI imaging mass spectrometry (IMS) is a powerful approach that facilitates the spatial analysis of molecular species in biological tissue samples2 (Fig.1). A 12 &mu;m thin tissue section is covered with a MALDI matrix, which facilitates desorption and ionization of intact peptides and proteins that can be detected with a mass analyzer, typically using a MALDI TOF/TOF mass spectrometer. Generally hundreds of peaks can be assessed in a single rat brain tissue section. In contrast to commonly used imaging techniques, this approach does not require prior knowledge of the molecules of interest and allows for unsupervised and comprehensive analysis of multiple molecular species while maintaining high molecular specificity and sensitivity2. Here we describe a MALDI IMS based approach for elucidating region-specific distribution profiles of neuropeptides in the rat brain of an animal model Parkinson's disease (PD). 
PD is a common neurodegenerative disease with a prevalence of 1% for people over 65 of age3,4. The most common symptomatic treatment is based on dopamine replacement using L-DOPA5. However this is accompanied by severe side effects including involuntary abnormal movements, termed L-DOPA-induced dyskinesias (LID)1,3,6. One of the most prominent molecular change in LID is an upregulation of the opioid precursor prodynorphin mRNA7. The dynorphin peptides modulate neurotransmission in brain areas that are essentially involved in movement control7,8. However, to date the exact opioid peptides that originate from processing of the neuropeptide precursor have not been characterized. Therefore, we utilized MALDI IMS in an animal model of experimental Parkinson's disease and L-DOPA induced dyskinesia. 
MALDI imaging mass spectrometry proved to be particularly advantageous with respect to neuropeptide characterization, since commonly used antibody based approaches targets known peptide sequences and previously observed post-translational modifications. By contrast MALDI IMS can unravel novel peptide processing products and thus reveal new molecular mechanisms of neuropeptide modulation of neuronal transmission. While the absolute amount of neuropeptides cannot be determined by MALDI IMS, the relative abundance of peptide ions can be delineated from the mass spectra, giving insights about changing levels in health and disease. In the examples presented here, the peak intensities of dynorphin B, alpha-neoendorphin and substance P were found to be significantly increased in the dorsolateral, but not the dorsomedial, striatum of animals with severe dyskinesia involving facial, trunk and orolingual muscles (Fig. 5). Furthermore, MALDI IMS revealed a correlation between dyskinesia severity and levels of des-tyrosine alpha-neoendorphin, representing a previously unknown mechanism of functional inactivation of dynorphins in the striatum as the removal of N-terminal tyrosine reduces the dynorphin's opioid-receptor binding capacity9. This is the first study on neuropeptide characterization in LID using MALDI IMS and the results highlight the potential of the technique for application in all fields of biomedical research.

MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson&#039;s Disease

Dopamine replacement pharmacotherapy using L-DOPA is the most commonly used symptomatic treatment of Parkinson&#x2019;s disease, but is accompanied by side effects including involuntary abnormal movements, termed dyskinesia 1. Here, a protocol for MALDI imaging mass spectrometry is presented that detects changes in rat brain neuropeptide levels related to dyskinesia.

MALDI imaging mass spectrometry (IMS) is a powerful approach that facilitates the spatial analysis of molecular species in biological tissue samples2 ...

Intraductal Injection of LPS as a Mouse Model of Mastitis: Signaling Visualized via an NF-&kappa;B Reporter Transgenic

Animal models of human disease are necessary in order to rigorously study stages of disease progression and associated mechanisms, and ultimately, as pre-clinical models to test interventions. In these methods, we describe a technique in which lipopolysaccharide (LPS) is injected into the lactating mouse mammary gland via the nipple, effectively modeling mastitis, or inflammation, of the gland. This simulated infection results in increased nuclear factor kappa B (NF-&kappa;B) signaling, as visualized through bioluminescent imaging of an NF-&kappa;B luciferase reporter mouse1.
Our ultimate goal in developing these methods was to study the inflammation associated with mastitis in the lactating gland, which often includes redness, swelling, and immune cell infiltration2,3. Therefore, we were keenly aware that incision or any type of wounding of the skin, the nipple, or the gland in order to introduce the LPS could not be utilized in our methods since the approach would likely confound the read-out of inflammation. We also desired a straight-forward method that did not require specially made hand-drawn pipettes or the use of micromanipulators to hold these specialized tools in place. Thus, we determined to use a commercially available insulin syringe and to inject the agent into the mammary duct of an intact nipple. This method was successful and allowed us to study the inflammation associated with LPS injection without any additional effects overlaid by the process of injection. In addition, this method also utilized an NF-&kappa;B luciferase reporter transgenic mouse and bioluminescent imaging technology to visually and quantitatively show increased NF-&kappa;B signaling within the LPS-injected gland4.
These methods are of interest to researchers of many disciplines who wish to model disease within the lactating mammary gland, as ultimately, the technique described here could be utilized for injection of a number of substances, and is not limited to only LPS.

Intraductal Injection of LPS as a Mouse Model of Mastitis: Signaling Visualized via an NF-&amp;kappa;B Reporter Transgenic

Described here is a technique in which lipopolysaccharide is injected into the lactating mouse mammary gland via the nipple to simulate mastitis, a condition commonly caused by bacterial infection. Lipopolysaccharide injection results in increased nuclear factor kappa B (NF-&kappa;B) signaling, visualized through bioluminescent imaging of an NF-&kappa;B luciferase reporter mouse.

Animal models of human disease are necessary in order to rigorously study stages of disease progression and associated mechanisms, and ultimately, as ...

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to &#8220;off-target&#8221; effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney.

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

We describe a method of generating a possible zebrafish model of polycystic kidney disease. We used Tg(wt1b:GFP) fish to visualize kidney structure. Knockdown of wnt5a was by morpholino injection. Pronephric cyst formation after wnt5a knockdown was observed in this GFP transgenic zebrafish.

Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The ...

Using Adeno-associated Virus as a Tool to Study Retinal Barriers in Disease

M&#252;ller cells are the principal glial cells of the retina. Their end-feet form the limits of the retina at the outer and inner limiting membranes (ILM), and in conjunction with astrocytes, pericytes and endothelial cells they establish the blood-retinal barrier (BRB). BRB limits material transport between the bloodstream and the retina while the ILM acts as a basement membrane that defines histologically the border between the retina and the vitreous cavity. Labeling M&#252;ller cells is particularly relevant to study the physical state of the retinal barriers, as these cells are an integral part of the BRB and ILM. Both BRB and ILM are frequently altered in retinal disease and are responsible for disease symptoms.
There are several well-established methods to study the integrity of the BRB, such as the Evans blue assay or fluorescein angiography. However these methods do not provide information on the extent of BRB permeability to larger molecules, in nanometer range. Furthermore, they do not provide information on the state of other retinal barriers such as the ILM. To study BRB permeability alongside retinal ILM, we used an AAV based method that provides information on permeability of BRB to larger molecules while indicating the state of the ILM and extracellular matrix proteins in disease states. Two AAV variants are useful for such study: AAV5 and ShH10. AAV5&#160;has a natural tropism for photoreceptors but it cannot get across to the outer retina when administered into the vitreous when the ILM is intact (i.e., in wild-type retinas). ShH10 has a strong tropism towards glial cells and will selectively label M&#252;ller glia in both healthy and diseased retinas. ShH10 provides more efficient gene delivery in retinas where ILM is compromised. These viral tools coupled with immunohistochemistry and blood-DNA analysis shed light onto the state of retinal barriers in disease.

To investigate the blood-retinal barrier permeability and the inner limiting membrane integrity in animal models of retinal disease, we used several adeno-associated virus (AAV) variants as tools to label retinal neurons and glia. Virus mediated reporter gene expression is then used as an indicator of retinal barrier permeability.

M&#252;ller cells are the principal glial cells of the retina. Their end-feet form the limits of the retina at the outer and inner limiting membranes ...

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis

Pyelonephritis is a bacterial infection of the kidney and is most commonly caused by Escherichia coli. Recurrent infections can cause significant renal inflammation and fibrosis ultimately resulting in declining kidney function. Before improved clinical management and prevention of pyelonephritis can be instituted, a reliable animal model must be established in order to study the mechanisms of progression, recurrence, and therapeutic efficacy. The transurethral infection model closely mimics human pyelonephritis but exhibits considerable variation due to its reliance on urethral reflux to transport the bacteria to the kidney. Herein, a detailed surgical protocol for performing bacterial injections into the rat renal pelvis is provided and confirmed by non-invasive Magnetic Resonance Imaging (MRI). Using this protocol, animals receive direct exposure to a desired concentration of E. coli bacteria and can fully recover from the surgical procedure with adequate post-operative care. This facilitates subsequent longitudinal MRI assessments of the experimental animal models for comparison with saline (sham) controls. Using this direct delivery approach, the severity of infection is controllable and applicable for mechanistic studies of progression as well as development of novel treatment strategies.

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis

This manuscript describes a rat surgical model of pyelonephritis using direct intra-renal infection by Escherichia coli into the renal pelvis. The experimental procedure can be utilized to study the pathogenesis of pyelonephritis as well as the associated inflammation and fibrosis.

Pyelonephritis is a bacterial infection of the kidney and is most commonly caused by Escherichia coli. Recurrent infections can cause significant renal ...

Development of a Direct Pulp-capping Model for the Evaluation of Pulpal Wound Healing and Reparative Dentin Formation in Mice

Dental pulp is a vital organ of a tooth fully protected by enamel and dentin. When the pulp is exposed due to cariogenic or iatrogenic injuries, it is often capped with biocompatible materials in order to expedite pulpal wound healing. The ultimate goal is to regenerate reparative dentin, a physical barrier that functions as a "biological seal" and protects the underlying pulp tissue. Although this direct pulp-capping procedure has long been used in dentistry, the underlying molecular mechanism of pulpal wound healing and reparative dentin formation is still poorly understood. To induce reparative dentin, pulp capping has been performed experimentally in large animals, but less so in mice, presumably due to their small sizes and the ensuing technical difficulties. Here, we present a detailed, step-by-step method of performing a pulp-capping procedure in mice, including the preparation of a Class-I-like cavity, the placement of pulp-capping materials, and the restoration procedure using dental composite. Our pulp-capping mouse model will be instrumental in investigating the fundamental molecular mechanisms of pulpal wound healing in the context of reparative dentin in vivo by enabling the use of transgenic or knockout mice that are widely available in the research community.

We describe a step-by-step method of performing direct pulp capping on mice teeth for the evaluation of pulpal wound healing and reparative dentin formation in vivo.

Dental pulp is a vital organ of a tooth fully protected by enamel and dentin. When the pulp is exposed due to cariogenic or iatrogenic injuries, it is ...

Development of Recombinant Proteins to Treat Chronic Pain

Chronic pain is difficult to treat and new approaches to resolve persistent pain are urgently needed. Anti-inflammatory cytokines are promising candidates for treating debilitating pain conditions due to their capacity to regulate aberrant neuro-immune interactions. However, physiologically they work in a network of various cytokines, and therefore their therapeutic effect may not be optimal when used as stand-alone drugs. To overcome this limitation, we developed a fusion protein of the anti-inflammatory cytokines IL4 and IL10. Here, we describe the methods for production and quality control of IL4-10 recombinant fusion protein and we test the effectiveness of the IL4-10 fusion protein to resolve pain in a mouse model of persistent inflammatory pain.

In this paper we provide details for the methods of production and quality control of an IL4-10 recombinant fusion protein. We also show how to test the effectiveness of this protein to resolve pain in a mouse model of inflammatory pain.

Chronic pain is difficult to treat and new approaches to resolve persistent pain are urgently needed. Anti-inflammatory cytokines are promising candidates ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...