Name: Clinical Score and Motor Performance Evaluation of Mouse Induced with Experimental Autoimmune Encephalomyelitis
Uploaded: 2023-10-13T13:10:00
Description: Watch this Scientific Journal Video about Clinical Score and Motor Performance Evaluation of Mouse Induced with Experimental Autoimmune Encephalomyelitis at JoVE.com

clinical score and motor performance evaluation of mouse induced with experimental autoimmune encephalomyelitis

Induction et évaluation de l’encéphalomyélite auto-immune expérimentale chez la souris

Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease affecting the central nervous system (CNS). It shows the presence of perivascular infiltration of inflammatory cells, demyelination, axonal loss, and gliosis1. Its etiology remains unknown, and its clinical aspects, radiographic, and pathological features suggest remarkable heterogeneity in the disease2.
Due to its unknown etiology and complexity, at present, no animal model recapitulates all the clinical and radiological features displayed in human MS3,4. However, various animal models are employed to study different aspects of MS3,4. In these models, disease initiation is typically extremely artificial, and the timeframe of the onset of clinical signs is different between humans and mice. For example, in humans, the pathophysiological processes underlying the disease are undetected for years before the onset of clinical manifestations. Conversely, the experimenters can detect symptoms in animal models within weeks or even days after MS induction4.
Three basic animal models produce the features of demyelination that are characteristic of MS: those that are virus-induced (e.g., Theiler&#39;s murine encephalomyelitis virus), those that are induced by toxic agents (e.g., cuprizone, lysolecithin), and the different variants of experimental autoimmune encephalomyelitis (EAE)5. Each model helps study some specific facets of the disease but none replicates all the features of MS6. Thus, it is critical to choose the correct model considering the specific experimental needs and the scientific questions to be addressed.
Thanks to immunization procedures against myelin-derived antigens, EAE is induced by triggering an autoimmune response to CNS components in susceptible mice. The interplay between a wide range of immunopathological and neuropathological mechanisms causes the development of principal pathological traits of MS (i.e., inflammation, demyelination, axonal loss, and gliosis) in the immunized mice7,8. Mice begin to show clinical symptoms around the second week after immunization and generally show ascending paralysis from the tail to the limb and forelimb. The clinical score (i.e., quantification of the accumulation of disease-related deficits) is generally assessed using a 5-point scale7.
Active immunization with protein or peptide or passive transfer of encephalitogenic T cells can be used to induce EAE in mice with different genetic backgrounds (e.g., SJL/J, C57BL/6, and non-obese-diabetic (NOD) mice). Myelin proteolipid protein (PLP), myelin basic protein (MBP), and myelin oligodendrocyte glycoprotein (MOG) are examples of self-CNS proteins from which immunogens are usually produced. Particularly, SJL/J mice immunized with the immunodominant epitope of PLP (PLP139&#8722;151) develop a relapsing-remitting (RR) disease course, while C57BL/6J mice immunized with the immunodominant MOG35-55 peptide show EAE of a chronic nature1. Despite some limitations, such as providing very little information about MS progression, the role of B cells in the disease, the inside-out mechanisms, or difficulties in studying remyelination, the EAE models have hugely contributed to the understanding of autoimmune and neuroinflammatory processes, increasing the knowledge in the MS field and thus allowing the development of novel therapeutic approaches for this disease4,6.
In the present work, we focused on a particular form of active EAE, the myelin oligodendrocyte glycoprotein peptide 35-55 (MOG35-55)-induced form9,10,11,12. The MOG35-55-induced EAE models a chronic form of MS. After immunization, the mice undergo an asymptomatic phase within the first week after immunization, then the disease typically arises during the second week after immunization, while between the third and fourth weeks after immunization, the disease becomes chronic, with no possibility of full recovery from the accumulated deficits7,8,13. Interestingly, no differences between males and females in incidence, disease onset, course, or progression are observed in most of the studies present in the literature14, even if fewer studies compare the disease in males and females.
In contrast, in humans, these parameters are known to be strongly sexually dimorphic2. MS affects more women than men; however, men generally develop a more aggressive form of the disease2. This evidence has suggested an essential, as well as complex, role of the gonadal hormones15; nevertheless, the role and the mechanism of action of sex hormones in the pathology remain unclear. Moreover, data from animal models support the idea that both estrogens and androgens exert positive effects on different tracts of the pathology in a sex-specific manner16,17.
Some studies also suggest neuroprotective, promyelinating, and anti-inflammatory effects of progesterone18 and, although evidence in MS patients is scarce18, neuroactive steroids (i.e., de novo synthetized steroids by the nervous system, such as pregnenolone, tetrahydroprogesterone, and dihydroprogesterone) might also affect the pathological course19. Collectively, these data support the idea that sex hormones produced both peripherally and inside the CNS have an important and sex-specific role in disease onset and progression. Therefore, in the present work, we urge the collection of separate data from both male and female animals.
From the histopathological point of view, the white matter of the spinal cord serves as the principal site of CNS injury in this model, which is characterized by multifocal, confluent regions of mononuclear inflammatory infiltration and demyelination8. Thus, in describing this protocol for the induction of MOG35-55-induced EAE in C57BL/6J mice, we will take into account the disease outcome in the two sexes and provide some histopathological insights regarding the spinal cords.

Pleins feux sur l’auteur : Création d’un modèle expérimental polyvalent d’encéphalomyélite auto-immune pertinent pour les souris mâles et femelles 

Modélisation de la sclérose en plaques chez les deux sexes : encéphalomyélite auto-immune expérimentale induite par MOG35-55

Our research focuses on the experimental autoimmune encephalomyelitis, or EAE model, which can significantly announce the understanding of peripheral immune-mediated mechanism and evaluate neuroinflammatory and partially delineating processes. This model has also been widely used to develop and test a wide range of therapeutics drugs. Due to the unknown etiology and complexity of multiple sclerosis, no animal model currently recapitulates all the clinical and radiological features displayed in humans.Thus, it is quite challenging for the researchers to select the animal model most fitting for a specific experimental question. EAE is a widely used model of multiple sclerosis. However, to do several issue, only some studies performing this model considered both sexes.With our protocol, we want a light possibility of including both sexes in the study conducted in this model. Specifically, our protocol proposed a clinical evaluation based of two methods:the clinical score assessment and the rotator test, leading a more quantitative, less subjective and more precise clinical assessment of the disease course. Even though this model does not entirely reproduce the sexual dimorphism of multiple sclerosis, it has potential advantages.The combination of the induction with other possible risk factor, especially the environmental ones, can end in understanding specific effects of such factors and identifying the specific role in some sexually dimorphic aspect of the disease.

Watch this Scientific Journal Video about Clinical Score and Motor Performance Evaluation of Mouse Induced with Experimental Autoimmune Encephalomyelitis at JoVE.com

Clinical Score and Motor Performance Evaluation of Mouse Induced with Experimental Autoimmune Encephalomyelitis  

Score clinique et évaluation des performances motrices d’une souris atteinte d’encéphalomyélite auto-immune expérimentale

Après avoir induit l’encéphalomyélite auto-immune expérimentale chez la souris, demandez à un investigateur en aveugle d’effectuer une évaluation quotidienne des scores cliniques de l’animal. Évaluez chaque animal sur une échelle de 0 à 5 pour évaluer la progression de la maladie. Pour évaluer les performances du moteur, initiez des séances Rotor-Rod pour les souris quotidiennement, en commençant à 1 DPI jusqu’à ce que l’étude l’exige.Effectuez chaque séance pendant 300 secondes, au cours desquelles augmentez la vitesse de rotation de la tige de manière linéaire de 4 à 40 rotations par minute. Lorsque l’animal perd l’équilibre et tombe du dispositif Rotor-Rod, il atterrit sur le sol, déclenchant un capteur qui enregistre l’heure. Enregistrez les performances de l’animal et notez-les comme une latence pour tomber.Une augmentation significative du score clinique ou CS avec le temps a été observée chez les souris mâles et femelles, à partir de 10 DPI jusqu’au point final. Les femmes présentaient un CS plus élevé que les hommes, mais pas de manière significative. Une tendance à l’apparition précoce de la maladie a également été observée chez les femmes par rapport aux hommes.De plus, les femmes présentaient un CS cumulatif significativement plus élevé que les hommes. Une diminution significative de la performance de la tige de rotor avec le temps a été observée chez les souris mâles et femelles. En particulier, les hommes affichaient la performance minimale à 16 DPI, tandis que les femmes à 17 DPI.Les hommes ont obtenu de meilleurs résultats que les femmes, en particulier pendant la phase chronique de la maladie, probablement en raison d’un CS plus faible.

Research

JoVE Journal

Neuroscience

Clinical Score and Motor Performance Evaluation of Mouse Induced with Experimental Autoimmune Encephalomyelitis

Modeling Multiple Sclerosis in the Two Sexes: MOG35-55-Induced Experimental Autoimmune Encephalomyelitis

Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease affecting the central nervous system (CNS). It is characterized by different ...

Recherche

Neurosciences

Preparation of MOG35-55 Emulsion for Immunization of Mouse

Preparation of MOG35-55 Emulsion for Immunization of Mouse  

Préparation de l’émulsion MOG35-55 pour l’immunisation de la souris

Immunization of Mouse with MOG35-55 to Induce Experimental Autoimmune Encephalomyelitis

Immunization of Mouse with MOG35-55 to Induce Experimental Autoimmune Encephalomyelitis  

Immunisation d’une souris avec MOG35-55 pour induire une encéphalomyélite auto-immune expérimentale