Supported by Funda&#231;&atilde;o de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ) and Conselho Nacional de Desenvolvimento Cient&iacute;fico e Tecnol&oacute;gico (CNPq). We are grateful to anonymous referees whose comments helped us improve both the manuscript and video.

All chemicals stored in solid form, such as 6-OHDA and apomorphine, were diluted in sterile injection water and filtered inside a laminar flow hood, to avoid contamination. In addition, neurotoxins and neuroactive substances were stored, prepared, handled and disposed according to regulations set by international guidelines6 and the local Biosafety Committee. 
1 - Anesthesia and surgery
Adult male Swiss mice (25-30g) are premedicated with Atropine (0.2 mg/Kg, s.c.) to reduce vagal tone and then anesthetized with an intraperitoneal injection of Ketamine (90-120 mg/Kg) and Xylazine (10 mg/Kg). The animal is placed on an electronically controlled heating pad (Insight) to ensure body temperature is maintained at 37&deg;C, as induction of sedation takes some minutes. The anesthesia level is checked throughout the procedure by testing the absence of withdrawal reflex. Anesthetic dosage should be ajusted for each strain/colony. Depending on the animal and duration of the surgery, additional doses of Ketamine may be necessary. After that, saline (NaCl 0,9%) is applied on both eyes to protect the corneas from drying out and test the absence of the blink reflex in this first moment. The fur over the entire head is shaved with a trimmer to ensure the minimum contact with unsterile areas. Local anesthetic (Xylocaine) is applied to the ear bars to prevent discomfort. Only once withdrawal and blink reflex have vanished, indicating the level of anesthesia is deep enough for surgery (stage 3), the animal is positioned on the stereotaxic frame using mouth-piece and ear bars specially designed for this species (Insight). Once positionated, an ophthalmologic ointment (MARCA) is applied to protect the animal eyes throughout all surgery. Only after be sure that the eyes are correctly protected, the procedure continue with the disinfection of the skin of the surgical region by repeating three applications of povidone iodine followed by 70% Ethanol, using sterile cottons swabs After, proper placement of the ear bars is ensured by testing for sideways movements of the head (the head must not move to ensure that the bars are securely fixed). Proper dorsoventral inclination of the head will be verified later when skull landmarks are revealed. A sagittal incision (1.5 cm) is made with a sterile scalpel (#15 blade). The periosteum over the area of interest is gently scraped away with a new blade, and the bone is wiped clean with sterile gaze and cotton swabs, to uncover skull landmarks: bregma is defined as the point of intersection of sagittal and coronal sutures, while lambda is the point of intersection of the sagittal suture and the best fit line passing through the left and right portions of the lambdoid suture. The tip of a vertically aligned reference needle is first zeroed at the bregma, under examination through the surgical microscope, and then moved as to touch the lambda point. If the head is properly positioned, lambda should be at the same dorso-ventral level as bregma, and both landmarks should be distant by 4.2 mm along the rostro-caudal axis. If not, the ears bars and nosepiece should be loosen and the head delicately tilted around the interaural axis, in order to achieve the desired position, which defines the "flat skull" reference for stereotaxical measures. The tip of the reference needle is then positioned at the desired coordinates: anterior-posterior (AP +0.5 mm) and lateral (L -2.0 mm, left). The location is marked on the skull and a small (1.2 mm diameter) hole is opened with a sterilized drill bit, using intermittent action to prevent heat the area. Bone fragments are carefully removed with a dental curette and washed with sterile warm 0.9% NaCl. The sterilized 5 &mu;l Hamilton syringe (26s gauge; 0.47 mm outer diameter) is loaded with the 6-OHDA solution (or vehicle for control animals) and vertically aligned in the stereotaxic apparatus. The tip of the needle (type 2 or 12&deg; bevel) is then inserted into the opened hole, until touch the pial surface, to determinate the reference point of the dorso-ventral coordinate. Once determinate this coordinate, the needle is slowly lowered to reach the coordinates of the striatum (AP: +0.5; L: -2.0 and DV: -3.0 mm, below pial surface7). The 6-OHDA solution (10 &mu;g 6-OHDA in 0.9% NaCl with 0.02% ascorbic acid), which was prepared and filtered inside a laminar flow hood, and must be protected from light by aluminum foil throughout the procedure, is then injected at a flow rate of 0.1&mu;L/min. For control animals, an equal volume of vehicle (0.02% ascorbic acid and 0.9% NaCl in sterile water) is injected. Once the entire 2.0 &mu;L has been injected, the syringe is kept in place for 5 min before being very slowly retracted from the brain, in no less than in 5 minutes. The skull is cleaned and the incision is closed using a #6-0 nylon suture (Shalon). To take a extra care against infection, a local antibiotic ointment, such as neomycin, may be applied to the sutured skin. Animals are removed from the frame, given 0.5 ml of saline (sc.) to prevent dehydration, and kept warm and under close observation until full recovery. They are then housed with food and water ad libitum. Analgesic is added to the drinking water bottle for the first two days after surgery (given an average daily water consumption of 5.5 ml, and a recommended dosage of 0.03 mg Ibuprofen/g of body weight/day; add 0,82 mL of 20 mg/mL Ibuprofen-Abbott suspension to 100 mL drinking water). Mice usually recover promptly from the procedure, wandering and reaching for water food pellets easily. In any case of apparent discomfort, or any sign of infection, animals should be euthanized according to local guidelines.
2 - Behavioral test
Although motor impairment can be observed after a week, a post-lesion interval of one month is allowed before reliable quantification with the rotation test. The animal receives a subcutaneous injection of DA agonist apomorphine (0.5 mg/Kg), and is placed in an opaque cylinder of 30 cm diameter, placed 45 cm below the recording camera. It is important to remove any residues and odors from previously tested animals before each test. After a 5 min habituation period, movements are recorded over a 5 min timeframe. Both contra- and ipsilateral full-body rotation are measured and compared with the control group (vehicle injected). If the procedure was correctly performed, control animals will not exhibit any rotation, whereas 6-OHDA lesioned animals will start turning to the contralateral side, since the agonist predominantly activates the supersensitive denervated striatum on the lesioned side. Animals scoring over 7 rpm (displaying at least 7 full-body contralateral rotations per minute) are considered as successfully lesioned. The animal can be safely returned to their housing 30 min after the test, which may be repeated weekly. In our hands, less than 5% of the lesioned mice displayed suboptimal rotation rates.

<ol>
	<li>Ungerstedt, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=6-hydroxy-dopamine+induced+degeneration+of+central+monoamine+neurons.">6-hydroxy-dopamine induced degeneration of central monoamine neurons.</a> Eur. J. Pharmacol. 5, 107-110 (1968).</li><li>Akerud, P., Canals, J. M., Snyder, E. Y., Arenas, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroprotection+through+delivery+of+glial+cell+line-derived+neurotrophic+factor+by+neural+stem+cells+in+a+mouse+model+of+Parkinson's+Disease.">Neuroprotection through delivery of glial cell line-derived neurotrophic factor by neural stem cells in a mouse model of Parkinson's Disease.</a> J. Neurosci. 21, 8108-8118 (2001).</li><li>Ghosh, A., Roy, A., Liu, X., Kordower, J. H., Mufson, E. J., Hartley, D. M., Ghosh, S., Mosley, R. L., Gendelman, H. E., Pahan, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+inhibition+of+NF-kappaB+activation+prevents+dopaminergic+neuronal+loss+in+a+mouse+model+of+Parkinson's+Disease.">Selective inhibition of NF-kappaB activation prevents dopaminergic neuronal loss in a mouse model of Parkinson's Disease.</a> Proc. Natl. Acad. Sci. USA. 104, 18754-18759 (2007).</li><li>Alvarez-Fischer, D., Henze, C., Strenzke, C., Westrich, J., Ferger, B., H&#246;glinger, G. U., Oertel, W. H., Hartmann, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+the+striatal+6-OHDA+model+of+Parkinson's+disease+in+wild+type+and+a-synuclein-deleted+mice.">Characterization of the striatal 6-OHDA model of Parkinson's disease in wild type and a-synuclein-deleted mice.</a> Exp. Neurol. 210, 182-193 (2008).</li><li>Ungerstedt, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=6-Hydroxydopamine-induced+degeneration+of+the+nigrostriatal+dopamine+pathway:+The+turning+syndrome.">6-Hydroxydopamine-induced degeneration of the nigrostriatal dopamine pathway: The turning syndrome.</a> Pharmacology and Therapeutics Part B: General and Systematic Pharmacology. 2, 37-40 (1976).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Guidelines for the Care and Use of Mammals in Neuroscience and Behaviour Research. , 209 (2003).</li><li>Franklin, K. B. J., Paxinos, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Mouse Brain in Stereotaxic Coordinates. , (1997).</li><li>Hudson, J. L., Horne, C. G. v. a. n., Str&#246;mberg, I., Brock, S., Clayton, J., Masserano, J., Hoffer, B. J., Gerhardt, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Correlation+of+apomorphine-+and+amphetamine-induced+turning+with+nigrostriatal+dopamine+content+in+unilateral+6-hydroxydopamine+lesioned+rats.+Brain+Res.">Correlation of apomorphine- and amphetamine-induced turning with nigrostriatal dopamine content in unilateral 6-hydroxydopamine lesioned rats. Brain Res.</a> , 626-6167 (1993).</li><li>Truong, L., Allbutt, H., Kassiou, M., Henderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developing+a+preclinical+model+of+Parkinson's+disease:+A+study+of+behaviour+in+rats+with+graded+6-OHDA+lesions.">Developing a preclinical model of Parkinson's disease: A study of behaviour in rats with graded 6-OHDA lesions.</a> Behav. Brain Res. 169, 1-9 (2006).</li><li>Harvey, B. K., Wang, Y., Hoffer, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transgenic+rodent+models+of+Parkinson's+disease.">Transgenic rodent models of Parkinson's disease.</a> Acta Neurochir. (Wien.). 101, 89-92 (2008).</li><li>Isacson, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ole+Isacson:+Development+of+New+Therapies+for+Parkinson's+Disease.">Ole Isacson: Development of New Therapies for Parkinson's Disease.</a> JoVE. 3, (2007).</li></ol>

Experiments were performed in accordance with the international Guidelines for the Care and Use of Mammals in Neuroscience and Behavior Research6, after approval by the Institutional Animal Care and Use Committee (Comiss&atilde;o de Avalia&#231;&atilde;o de Uso de Animais em Pesquisa: UFRJ/CAUAP protocol #DAHEICB 027). Adequate measures were taken to minimize the pain and discomfort of the experimental animals.

Extensive unilateral lesion of the nigro-striatal pathway can be achieved reliably in mice by a single stereotaxic injection of 6-OHDA into the striatum. The extent of the lesion can be verified post-mortem by immunohistochemistry for Tyrosine Hydroxylase (which catalyses the rate limiting stage of the synthesis of DA, i.e. the conversion of L-Tyrosine to dihydroxyphenylalanine), as illustrated in the video.
In vivo, contralateral rotations induced by apomorphine are a better predictor of max...

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		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
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<td>Ketamine hydrochloride</td>
<td>&nbsp;</td>
<td>K&ouml;nig</td>
<td>&nbsp;</td>
<td>90-120 mg/Kg</td>
</tr>
<tr>
<td>Xylazine hydrochloride</td>
<td>&nbsp;</td>
<td>K&ouml;nig</td>
<td>&nbsp;</td>
<td>10 mg/Kg</td>
</tr>
<tr>
<td>Atropine Sulfate</td>
<td>&nbsp;</td>
<td>Isofarma</td>
<td>&nbsp;</td>
<td>Isofarma</td>
</tr>
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<td>6 &#x2013; Hydroxydopamine Hydrochloride</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>&nbsp;</td>
<td>5 &mu;g/&mu;L</td>
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<td>L - Ascorbic Acid</td>
<td>&nbsp;</td>
<td>USB Corporation</td>
<td>&nbsp;</td>
<td>0.2%</td>
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<td>Xylocaine (Lidocaine Chloridrate)</td>
<td>&nbsp;</td>
<td>ASTRA Chemistry</td>
<td>&nbsp;</td>
<td>5% 50 mg</td>
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<tr>
<td>Nebacetin (Neomycin Sulfate + Bacitracin)</td>
<td>&nbsp;</td>
<td>Altana Pharma</td>
<td>&nbsp;</td>
<td>5 mg/g + 250 Ul/g</td>
</tr>
<tr>
<td>R-(-)-Apomorphine hydrochloride</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>&nbsp;</td>
<td>0.5 mg/Kg</td>
</tr>
<tr>
<td>GenTeal lOphthalmic ointment Hypromellose</td>
<td>&nbsp;</td>
<td>NOVARTIS</td>
<td>&nbsp;</td>
<td> 0.33%</td>
</tr>
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<td>Ibuprofen</td>
<td>&nbsp;</td>
<td>Abbott</td>
<td>&nbsp;</td>
<td>4 mg/ 100 ml drinking water</td>
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<td>Povidine</td>
<td>&nbsp;</td>
<td>JohnsonDiversey</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
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<td>R-(-)-Apomorphine hydrochloride</td>
<td>&nbsp;</td>
<td>Sigma-Aldrich</td>
<td>&nbsp;</td>
<td>0.5 mg/Kg</td>
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murine model for parkinson's disease: from 6-oh dopamine lesion to behavioral test

Parkinson's disease (PD) affects at least 6.5 million people worldwide, irrespective of gender, social, ethnic, economic, or geographic boundaries. Key symptoms, such as tremor, rigidity and bradikinesia, develop when about 3/4 of dopaminergic cells are lost in the substantia nigra, and fail to provide for the smooth, coordinated regulation of striatal motor circuits. Depression and hallucinations are common, and dementia eventually occurs in 20% of patients. At this time, there is no treatment to delay or stop the progression of PD. Rather, the medications currently available aim more towards the alleviation of these symptoms. New surgical strategies may reversibly switch on the functionally damaged circuits through the electrical stimulation of deep brain structures, but although deep brain stimulation is a major advance, it is not suitable for all patients. It remains therefore necessary to test new cell therapy approaches in preclinical models.
Selective neurotoxic disruption of dopaminergic pathways can be reproduced by injection of 6-hydroxydopamine (6-OHDA) or MPTP (1-methyl-4-phenyl-1,2,3,6-tertahydropyridine) whereas depleting drugs and oxidative-damaging chemicals may also reproduce specific features of PD in rodents. Unlike MPTP, 6-OHDA lesions cause massive irreversible neuronal loss, and can be uni- or bilateral. The 6-OHDA lesion model is reliable, leads to robust motor deficits, and is the most widely used after 40 years of research in rats1. As interactions between grafted cells and host can now be studied more thoroughly in mice rather than in rats, the model has been transposed to mice2,3, where it has been recently characterized4.
In this video, we demonstrate how to lesion the left nigro-striatal pathway of anesthetized mice by slowly delivering 2.0 &mu;L of 6-OHDA through a stereotaxically inserted micro-syringe needle. The loss of dopaminergic input occurs within days, and the functional impairments can be monitored over post-operative weeks and months by rating animal rotations induced by dopaminergic agents5. Here, we show full-body contralateral rotations occurring 10 minutes after a single subcutaneous administration of apomorphine, measured one month after the lesion. Outcomes and drawbacks are discussed below.

Watch this Scientific Journal Video about Murine Model for Parkinson's Disease: from 6-OH Dopamine Lesion to Behavioral Test at JoVE.com

Murine Model for Parkinson&#039;s Disease: from 6-OH Dopamine Lesion to Behavioral Test

Parkinson disease is caused by loss of dopaminergic innervation to the striatum, which can be experimentally induced by 6-OH-dopamine. We describe how to perform a stereotaxic lesion and to monitor apomorphine-induced rotational behavior in mice. This model is useful and reliable for testing new therapies for Parkinson disease.

Murine Model for Parkinson's Disease: from 6-OH Dopamine Lesion to Behavioral Test

Parkinson's disease (PD) affects at least 6.5 million people worldwide, irrespective of gender, social, ethnic, economic, or geographic boundaries. Key ...

murine-model-for-parkinson-s-disease-from-6-oh-dopamine-lesion-to

Research

JoVE Journal

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31.4K Views.  Universidade Federal do Rio de Janeiro, Brasil. Parkinson disease is caused by loss of dopaminergic innervation to the striatum, which can be experimentally induced by 6-OH-dopamine. We describe how to perform a stereotaxic lesion and to monitor apomorphine-induced rotational behavior in mice. This model is useful and reliable for testing new therapies for Parkinson disease.

Video: Murine Model for Parkinson's Disease: from 6-OH Dopamine Lesion to Behavioral Test

Ole Isacson: Development of New Therapies for Parkinson's Disease

Ole Isacson gives a concise overview of Parkinsons's disease, its causes, therapeutic strategies, and advances in Parkinson's research.

Primary Dissociated Midbrain Dopamine Cell Cultures from Rodent Neonates

The ability to create primary cell cultures of dopamine neurons allows for the study of the presynaptic characteristics of dopamine neurons in isolation from systemic input from elsewhere in the brain. In our lab, we use these neurons to assess dopamine release kinetics using carbon fiber amperometry, as well as expression levels of dopamine related genes and proteins using quantitative PCR and immunocytochemistry. In this video, we show you how we generate these cultures from rodent neonates.
The process involves several steps, including the plating of cortical glial astrocytes, the conditioning of neuronal cell culture media by the glial substrate, the dissection of the midbrain in neonates, the digestion, extraction and plating of dopamine neurons and the addition of neurotrophic factors to ensure cell survival.
The applications suitable for such a preparation include electrophysiology, immunocytochemistry, quantitative PCR, video microscopy (i.e., of real-time vesicular fusion with the plasma membrane), cell viability assays and other toxicological screens.

Primary dissociated midbrain dopamine cell cultures allow for the study of presynaptic characteristics of dopamine neurons. They can be used to monitor real-time dopamine release kinetics and protein/mRNA levels of regulators of dopamine exocytosis. Here, we show you how to generate these cultures from rodent neonates.

The ability to create primary cell cultures of dopamine neurons allows for the study of the presynaptic characteristics of dopamine neurons in isolation ...

Application of a C. elegans Dopamine Neuron Degeneration Assay for the Validation of Potential Parkinson's Disease Genes

Improvements to the diagnosis and treatment of Parkinson's disease (PD) are dependent upon knowledge about susceptibility factors that render populations at risk. In the process of attempting to identify novel genetic factors associated with PD, scientists have generated many lists of candidate genes, polymorphisms, and proteins that represent important advances, but these leads remain mechanistically undefined. Our work is aimed toward significantly narrowing such lists by exploiting the advantages of a simple animal model system. While humans have billions of neurons, the microscopic roundworm Caenorhabditis elegans has precisely 302, of which only eight produce dopamine (DA) in hemaphrodites. Expression of a human gene encoding the PD-associated protein, alpha-synuclein, in C. elegans DA neurons results in dosage and age-dependent neurodegeneration.
Worms expressing human alpha-synuclein in DA neurons are isogenic and express both GFP and human alpha-synuclein under the DA transporter promoter (Pdat-1). The presence of GFP serves as a readily visualized marker for following DA neurodegeneration in these animals. We initially demonstrated that alpha-synuclein-induced DA neurodegeneration could be rescued in these animals by torsinA, a protein with molecular chaperone activity 1. Further, candidate PD-related genes identified in our lab via large-scale RNAi screening efforts using an alpha-synuclein misfolding assay were then over-expressed in C. elegans DA neurons. We determined that five of seven genes tested represented significant candidate modulators of PD as they rescued alpha-synuclein-induced DA neurodegeneration 2. Additionally, the Lindquist Lab (this issue of JoVE) has performed yeast screens whereby alpha-synuclein-dependent toxicity is used as a readout for genes that can enhance or suppress cytotoxicity. We subsequently examined the yeast candidate genes in our C. elegans alpha-synuclein-induced neurodegeneration assay and successfully validated many of these targets 3, 4.
Our methodology involves generation of a C. elegans DA neuron-specific expression vector using recombinational cloning of candidate gene cDNAs under control of the Pdat-1 promoter. These plasmids are then microinjected in wild-type (N2) worms, along with a selectable marker for successful transformation. Multiple stable transgenic lines producing the candidate protein in DA neurons are obtained and then independently crossed into the alpha-synuclein degenerative strain and assessed for neurodegeneration, at both the animal and individual neuron level, over the course of aging.

Application of a C. elegans Dopamine Neuron Degeneration Assay for the Validation of Potential Parkinson&#039;s Disease Genes

This video demonstrates how to use C. elegans to assess dopaminergic neuron neurodegeneration as a model for Parkinson's disease. Furthermore, genetic screens are used to identify factors that either enhance degeneration or are neuroprotective.

Improvements to the diagnosis and treatment of Parkinson's disease (PD) are dependent upon knowledge about susceptibility factors that render populations ...

Xenopus laevis as a Model to Identify Translation Impairment

Protein synthesis is a fundamental process to gene expression impacting diverse biological processes notably adaptation to environmental conditions. The initiation step, which involves the assembly of the ribosomal subunits at the mRNA initiation codon, involved initiation factor including eIF4G1. Defects in this rate limiting step of translation are linked to diverse disorders. To study the potential consequences of such deregulations, Xenopus laevis oocytes constitute an attractive model with high degrees of conservation of essential cellular and molecular mechanisms with human. In addition, during meiotic maturation, oocytes are transcriptionally repressed and all necessary proteins are translated from preexisting, maternally derived mRNAs. This inexpensive model enables exogenous mRNA to become perfectly integrated with an effective translation. Here is described a protocol for assessing translation with a factor of interest (here eIF4G1) using stored maternal mRNA that are the first to be polyadenylated and translated during oocyte maturation as a physiological readout. At first, mRNA synthetized by in vitro transcription of plasmids of interest (here eIF4G1) are injected in oocytes and kinetics of oocyte maturation by Germinal Vesicle Breakdown detection is determined. The studied maternal mRNA target is the serine/threonine-protein-kinase mos. Its polyadenylation and its subsequent translation are investigated together with the expression and phosphorylation of proteins of the mos signaling cascade involved in oocyte maturation. Variations of the current protocol to put forward translational defects are also proposed to emphasize its general applicability. In light of emerging evidence that aberrant protein synthesis may be involved in the pathogenesis of neurological disorders, such a model provides the opportunity to easily assess this impairment and identify new targets.

Xenopus laevis as a Model to Identify Translation Impairment

Protein synthesis control occurs mainly at the translation initiation step, deficiencies in which are linked to diverse disorders. To better understand their etiology, we described here a protocol using Xenopus laevis oocytes assessing the translation of mos transcript in the presence of a mutant of translation initiation factor eIF4G1.

Protein synthesis is a fundamental process to gene expression impacting diverse biological processes notably adaptation to environmental conditions. The ...

Magnetic-Activated Cell Sorting Strategies to Isolate and Purify Synovial Fluid-Derived Mesenchymal Stem Cells from a Rabbit Model

Mesenchymal stem cells (MSCs) are the main cell source for cell-based therapy. MSCs from articular cavity synovial fluid could potentially be used for cartilage tissue engineering. MSCs from synovial fluid (SF-MSCs) have been considered promising candidates for articular regeneration, and their potential therapeutic benefit has made them an important research topic of late. SF-MSCs from the knee cavity of the New Zealand white rabbit can be employed as an optimized translational model to assess human regenerative medicine. By means of CD90-based magnetic activated cell sorting (MACS) technologies, this protocol successfully obtains rabbit SF-MSCs (rbSF-MSCs) from this rabbit model and further fully demonstrates the MSC phenotype of these cells by inducing them to differentiate to osteoblasts, adipocytes, and chondrocytes. Therefore, this approach can be applied in cell biology research and tissue engineering using simple equipment and procedures.

This article presents a simple and economic protocol for the straightforward isolation and purification of mesenchymal stem cells from New Zealand white rabbit synovial fluid.

Mesenchymal stem cells (MSCs) are the main cell source for cell-based therapy. MSCs from articular cavity synovial fluid could potentially be used for ...

Noninvasive Monitoring of Lesion Size in a Heterologous Mouse Model of Endometriosis

Here, we describe a protocol for the implementation of a heterologous mouse model in which progression of endometriosis can be assessed in real time through noninvasive monitoring of fluorescence emitted by implanted ectopic human endometrial tissue. For this purpose, biopsies of human endometrium are obtained from donor women ongoing oocyte donation. Human endometrial fragments are cultured in the presence of adenoviruses engineered to express cDNA for the reporter fluorescent protein mCherry. Upon visualization, labeled tissues with an optimal rate of fluorescence after infection are subsequently chosen for the implantation in recipient mice. One week prior to the implantation surgery, recipient mice are oophorectomized, and estradiol pellets are placed subcutaneously to sustain the survival and growth of lesions. On the day of surgery mice are anesthetized, and peritoneal cavity accessed through a small (1.5 cm) incision by the linea-alba. Fluorescently labeled implants are tweezed, briefly soaked in glue and attached to the peritoneal layer. Incisions are sutured, and animals left to recover for a couple of days. Fluorescence emitted by endometriotic implants is usually non-invasively monitored every 3 days for 4 weeks with an in vivo imaging system. Variations in the size of endometriotic implants can be estimated in real time by quantification of the mCherry signal and normalization against the initial time-point showing maximal fluorescence intensity.
Traditional preclinical rodents of models of endometriosis do not allow non-invasive monitoring of lesion in real time but rather allow evaluation of the effects of drugs assayed at the end point. This protocol allows one to track lesions in real time and is more useful to explore the therapeutic potential of drugs in preclinical models of endometriosis. The main limitation of the model thus generated is that non-invasive monitoring is not possible over long periods of time due to the episomal expression of Ad-virus.

Here, we present a protocol for live-imaging of fluorescently labeled human endometrial fragments grafted in mice. The method allows studying the effects of drugs of choice on endometriotic lesion size through monitoring and quantification of fluorescence emitted by the fluorescent reporter on real time

Here, we describe a protocol for the implementation of a heterologous mouse model in which progression of endometriosis can be assessed in real time ...

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A)

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer progression. How the chromosomal location and function of a centromere (i.e., centromere identity) are determined and participate in accurate chromosome segregation is a fundamental question. CENP-A is proposed to be the non-DNA indicator (epigenetic mark) of centromere identity, and CENP-A ubiquitylation is required for CENP-A deposition at the centromere, inherited through dimerization between cell division, and indispensable to cell viability.
Here we describe mass spectrometry analysis to identify ubiquitylation of EYFP-CENP-A K124R mutant suggesting that ubiquitylation at a different lysine is induced because of the EYFP tagging in the CENP-A K124R mutant protein. Lysine 306 (K306) ubiquitylation in EYFP-CENP-A K124R was successfully identified, which corresponds to lysine 56 (K56) in CENP-A through mass spectrometry analysis. A caveat is discussed in the use of GFP/EYFP or the tagging of high molecular weight protein as a tool to analyze the function of a protein. Current technical limit is also discussed for the detection of ubiquitylated bands, identification of site-specific ubiquitylation(s), and visualization of ubiquitylation in living cells or a specific single cell during the whole cell cycle.
The method of mass spectrometry analysis presented here can be applied to human CENP-A protein with different tags and other centromere-kinetochore proteins. These combinatory methods consisting of several assays/analyses could be recommended for researchers who are interested in identifying functional roles of ubiquitylation.

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A EYFP-CENP-A

CENP-A ubiquitylation is an important requirement for CENP-A deposition at the centromere, inherited through dimerization between cell division, and indispensable to cell viability. Here we describe mass spectrometry analysis to identify ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A) protein.

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer ...

Isolation of High Quality Murine Atrial and Ventricular Myocytes for Simultaneous Measurements of Ca2+ Transients and L-Type Calcium Current

Mouse models play a crucial role in arrhythmia research and allow studying key mechanisms of arrhythmogenesis including altered ion channel function and calcium handling. For this purpose, atrial or ventricular cardiomyocytes of high quality are necessary to perform patch-clamp measurements or to explore calcium handling abnormalities. However, the limited yield of high-quality cardiomyocytes obtained by current isolation protocols does not allow both measurements in the same mouse. This article describes a method to isolate high-quality murine atrial and ventricular myocytes via retrograde enzyme-based Langendorff perfusion, for subsequent simultaneous measurements of calcium transients and L-type calcium current from one animal. Mouse hearts are obtained, and the aorta is rapidly cannulated to remove blood. Hearts are then initially perfused with a calcium-free solution (37 &#176;C) to dissociate the tissue at the level of intercalated discs and afterwards with an enzyme solution containing little calcium to disrupt extracellular matrix (37 &#176;C). The digested heart is subsequently dissected into atria and ventricles. Tissue samples are chopped into small pieces and dissolved by carefully pipetting up and down. The enzymatic digestion is stopped, and cells are stepwise reintroduced to physiologic calcium concentrations. After loading with a fluorescent Ca2+-indicator, isolated cardiomyocytes are prepared for simultaneous measurement of calcium currents and transients. Additionally, isolation pitfalls are discussed and patch-clamp protocols and representative traces of L-type calcium currents with simultaneous calcium transient measurements in atrial and ventricular murine myocytes isolated as described above are provided.

Isolation of High Quality Murine Atrial and Ventricular Myocytes for Simultaneous Measurements of Ca2+ Transients and L-Type Calcium Current

Mouse models allow studying key mechanisms of arrhythmogenesis. For this purpose, high quality cardiomyocytes are necessary to perform patch-clamp measurements. Here, a method to isolate murine atrial and ventricular myocytes via retrograde enzyme-based Langendorff perfusion, which allows simultaneous measurements of calcium-transients and L-type calcium current, is described.

Mouse models play a crucial role in arrhythmia research and allow studying key mechanisms of arrhythmogenesis including altered ion channel function and ...

Rating L-DOPA-Induced Dyskinesias in the Unilaterally 6-OHDA-Lesioned Rat Model of Parkinson's Disease

L-DOPA-induced dyskinesias (LIDs) refer to motor complications that arise from prolonged L-DOPA administration to patients with Parkinson's disease (PD). The most common pattern observed in the clinic is the peak-dose dyskinesia which consists of clinical manifestations of choreiform, dystonic, and ballistic movements. The 6-hydroxydopamine (6-OHDA) rat model of PD mimics several characteristics of LIDs. After repeated L-DOPA administration, 6-OHDA-lesioned rats exhibit dyskinetic-like movements (e.g., abnormal involuntary movements, AIMs). This protocol demonstrates how to induce and analyze AIMs in 6-OHDA-lesioned rats with 90%-95% dopaminergic depletion in the nigrostriatal pathway. Repeated administration (3 weeks) of L-DOPA (5 mg/kg, combined with 12.5 mg/kg of benserazide) can induce the development of AIMs. The time course analysis reveals a significant increase in AIMs at 30-90 min (peak-dose dyskinesia). Rodent models of LIDs are an important preclinical tool to identify effective antidyskinetic interventions.

Rodent models of L-DOPA-induced dyskinesias are invaluable tools to identify therapeutic interventions to attenuate the development or alleviate the manifestations that emerge due to the repeated administration of L-DOPA. This protocol demonstrates how to induce and analyze dyskinetic-like movements in the unilaterally 6-OHDA-lesioned rat model of Parkinson's disease.

L-DOPA-induced dyskinesias (LIDs) refer to motor complications that arise from prolonged L-DOPA administration to patients with Parkinson's disease (PD). ...

3D Culture of Organoids from Murine Intestinal Crypts and Single Stem Cell

The 3D Culturing of Organoids from Murine Intestinal Crypts and a Single Stem Cell for Organoid Research

At present, organoid culture represents an important tool for in vitro studies of different biological aspects and diseases in different organs. Murine small intestinal crypts can form organoids that mimic the intestinal epithelium when cultured in a 3D extracellular matrix. The organoids are composed of all cell types that fulfill various intestinal homeostatic functions. These include Paneth cells, enteroendocrine cells, enterocytes, goblet cells, and tuft cells. Well-characterized molecules are added into the culture medium to enrich the intestinal stem cells (ISCs) labeled with leucine-rich repeats containing G protein-coupled receptor 5 and are used to drive differentiation down specific lineages; these molecules include epidermal growth factor, Noggin (a bone morphogenetic protein), and R-spondin 1. Additionally, a protocol to generate organoids from a single erythropoietin-producing hepatocellular receptor B2 (EphB2)-positive ISC is also detailed. In this methods article, techniques to isolate small intestinal crypts and a single ISC from tissues and ensure the efficient establishment of organoids are described.

Author Spotlight: The 3D Culturing of Organoids from Murine Intestinal Crypts and a Single Stem Cell for Organoid Research  

We describe a protocol to isolate murine small intestinal crypts and culture intestinal 3D organoids from the crypts. Additionally, we describe a method to generate organoids from a single intestinal stem cell in the absence of a sub-epithelial cellular niche.

At present, organoid culture represents an important tool for in vitro studies of different biological aspects and diseases in different organs. Murine ...