Ce travail est soutenu par des subventions des Instituts canadiens de recherche en santé (IRSC) et par la maladie de Crohn et la colite Fondation du Canada (CCFC).

<ol>
	<li>Sands, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+symptom+to+diagnosis:+clinical+distinctions+among+various+forms+of+intestinal+inflammation.">From symptom to diagnosis: clinical distinctions among various forms of intestinal inflammation.</a> Gastroenterology. 126, 1518-1532 (2004).</li><li>Danese, S., Fiocchi, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Etiopathogenesis+of+inflammatory+bowel+diseases.">Etiopathogenesis of inflammatory bowel diseases.</a> World J. Gastroenterol. 12, 4807-4812 (2006).</li><li>Wirtz, S., Neufert, C., Weigmann, B., Neurath, M. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemically+induced+mouse+models+of+intestinal+inflammation.">Chemically induced mouse models of intestinal inflammation.</a> Nat. Protoc. 2, 541-546 (2007).</li><li>Axelsson, L. G., Landstrom, E., Goldschmidt, T. J., Gronberg, A., Bylund-Fellenius, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dextran+sulfate+sodium+(DSS)+induced+experimental+colitis+in+immunodeficient+mice:+effects+in+CD4(+)-cell+depleted,+athymic+and+NK-cell+depleted+SCID+mice.">Dextran sulfate sodium (DSS) induced experimental colitis in immunodeficient mice: effects in CD4(+)-cell depleted, athymic and NK-cell depleted SCID mice.</a> Inflamm. Res. 45, 181-191 (1996).</li><li>Egger, B., Bajaj-Elliott, M., MacDonald, T. T., Inglin, R., Eysselein, V. E., Büchler, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterisation+of+acute+murine+dextran+sodium+sulphate+colitis:+cytokine+profile+and+dose+dependency.">Characterisation of acute murine dextran sodium sulphate colitis: cytokine profile and dose dependency.</a> Digestion. 62, 240-248 (2000).</li><li>Krawisz, J. E., Sharon, P., Stenson, W. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+assay+for+acute+intestinal+inflammation+based+on+myeloperoxidase+activity.+Assessment+of+inflammation+in+rat+and+hamster+models.">Quantitative assay for acute intestinal inflammation based on myeloperoxidase activity. Assessment of inflammation in rat and hamster models.</a> Gastroenterology. 87, 1344-1350 (1984).</li><li>Cooper, H. S., Murthy, S. N., Shah, R. S., Sedergran, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinicopathologic+study+of+dextran+sulfate+sodium+experimental+murine+colitis.">Clinicopathologic study of dextran sulfate sodium experimental murine colitis.</a> Lab. Invest. 69, 238-249 (1993).</li><li>Smith, J. W., Castro, 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=Relation+of+peroxidase+activity+in+gut+mucosa+to+inflammation.">Relation of peroxidase activity in gut mucosa to inflammation.</a> Am. J. Physiol. 234, R72-R79 (1978).</li><li>Ghia, J. E., Blennerhassett, P., Kumar-Ondiveeran, H., Verdu, E. F., Collins, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+vagus+nerve:+a+tonic+inhibitory+influence+associated+with+inflammatory+bowel+disease+in+a+murine+model.">The vagus nerve: a tonic inhibitory influence associated with inflammatory bowel disease in a murine model.</a> Gastroenterology. 131, 1122-1130 (2006).</li><li>Okayasu, I., Hatakeyama, S., Yamada, M., Ohkusa, T., Inagaki, Y., Nakaya, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+method+in+the+induction+of+reliable+experimental+acute+and+chronic+ulcerative+colitis+in+mice.">A novel method in the induction of reliable experimental acute and chronic ulcerative colitis in mice.</a> Gastroenterology. 98, 694-702 (1990).</li><li>Solomon, L., Mansor, S., Mallon, P., Donnelly, E., Hoper, M., Loughrey, M., Kirk, S., Gardiner, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dextran+sulphate+sodium+(DSS)+model+of+colitis:+an+overview.">The dextran sulphate sodium (DSS) model of colitis: an overview.</a> Comparative Clinical Pathology. 19, 235-239 (2010).</li><li>Mähler, M., Bristol, I. J., Leiter, E. H., Workman, A. E., Birkenmeier, E. H., Elson, C. O., Sundberg, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+susceptibility+of+inbred+mouse+strains+to+dextran+sulfate+sodium-induced+colitis.">Differential susceptibility of inbred mouse strains to dextran sulfate sodium-induced colitis.</a> Am. J. Physiol. 274, G544-G551 (1998).</li><li>Hans, W., Scholmerich, J., Gross, V., Falk, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+the+resident+intestinal+flora+in+acute+and+chronic+dextran+sulfate+sodium-induced+colitis+in+mice.">The role of the resident intestinal flora in acute and chronic dextran sulfate sodium-induced colitis in mice.</a> Eur. J. Gastroenterol. Hepatol. 12, 267-273 (2000).</li><li>Rath, H. C., Schultz, M., Freitag, R., Dieleman, L. A., Li, F., Linde, H., Schölmerich, J., Sartor, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Different+subsets+of+enteric+bacteria+induce+and+perpetuate+experimental+colitis+in+rats+and+mice.">Different subsets of enteric bacteria induce and perpetuate experimental colitis in rats and mice.</a> Infect. Immun. 69, 2277-2285 (2001).</li><li>Ghia, J. E., Li, N., Wang, H., Collins, M., Deng, Y., El-Sharkawy, R. T., Côté, F., Mallet, J., Khan, W. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+has+a+key+role+in+pathogenesis+of+experimental+colitis.">Serotonin has a key role in pathogenesis of experimental colitis.</a> Gastroenterology. 137, 1649-1660 (2009).</li><li>Elson, C. O., Beagley, K. W., Sharmanov, A. T., Fujihashi, K., Kiyono, H., Tennyson, G. S., Cong, Y., Black, C. A., Ridwan, B. W., McGhee, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hapten-induced+model+of+murine+inflammatory+bowel+disease:+mucosa+immune+responses+and+protection+by+tolerance.">Hapten-induced model of murine inflammatory bowel disease: mucosa immune responses and protection by tolerance.</a> J. Immunol. 157, 2174-2185 (1996).</li><li>Dieleman, L. A., Ridwan, B. U., Tennyson, G. S., Beagley, K. W., Bucy, R. P., Elson, C. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dextran+sulfate+sodium-induced+colitis+occurs+in+severe+combined+immunodeficient+mice.">Dextran sulfate sodium-induced colitis occurs in severe combined immunodeficient mice.</a> Gastroenterology. 107, 1643-1652 (1994).</li></ol>

Pas de conflits d&#39;intérêt déclarés.

DSS colite est un modèle largement utilisé chimiquement induite de l&#39;inflammation intestinale. Dans ce modèle, les souris sont donnés en eau potable complétée par le MAS, qui est pensé pour être toxiques pour les cellules épithéliales intestinales et perturber l&#39;intégrité de la barrière muqueuse. Administration du 10 DSS induit une colite aiguë qui se caractérise par des selles molles, des saignements fécale, et l&#39;infiltration avec des granulocytes. 10 Pendant DSS admini...

<table border="1"><tbody><tr><td> Nom de réactif / équipements: </td><td> Société </td><td> Numéro de catalogue </td><td> Commentaires </td></tr><tr><td> Tube Eppendorf Safe-Lock Microcentrifugeuse (2 ml) </td><td> Eppendorf </td><td> 0030 120.094 </td><td></td></tr><tr><td> Biotek EL808 lecteur de plaque d&#39;absorbance </td><td> Biotek </td><td> EL808 </td><td></td></tr><tr><td> Dextran sulfate de sodium du sel de qualité réactif (poids moléculaire 36,000-50,000 Da) </td><td> MP Biomédical </td><td> 160110 </td><td></td></tr><tr><td> Gen5 (logiciel) </td><td> Biotek </td><td> Version 1.10.8 </td><td></td></tr><tr><td> Bromure de Hexadecyltrimethylammonium (CCFH) </td><td> Sigma-Aldrich </td><td> H5882-100G </td><td></td></tr><tr><td> Le peroxyde d&#39;hydrogène, 30 wt.% Solution dans l&#39;eau </td><td> Sigma-Aldrich </td><td> 216763 </td><td> Conserver à 2-8 ° C </td></tr><tr><td> Microtest plmangeaient de 96 puits à fond plat </td><td> Sarstedt </td><td> 82.1581 </td><td> A usage unique </td></tr><tr><td> o-dianisidine </td><td> Sigma-Aldrich </td><td> D-3252 </td><td> Sensible à la lumière. Conserver à 2-8 ° C </td></tr><tr><td> Phosphate de potassium, dibasique </td><td> Caledon </td><td> 6620-1 </td><td></td></tr><tr><td> Phosphate de potassium, monobasique </td><td> EMD Chemicals </td><td> PX1565-1 </td><td></td></tr><tr><td> Cocktail d&#39;inhibiteurs de protéase </td><td> Sigma-Aldrich </td><td> P8340 </td><td> Conserver à -20 ° C </td></tr><tr><td> Triton X-100 </td><td> Sigma-Aldrich </td><td> T8787 </td><td></td></tr><tr><td> Tungstène carbure perles pour les tissus Lyser II </td><td> QUIAGEN </td><td> 69997 </td><td></td></tr></tbody></table>

investigating intestinal inflammation in dss-induced model of ibd

Les maladies intestinales inflammatoires (MII) englobe un éventail de pathologies intestinales, la plus commune qui sont la colite ulcéreuse (CU) et maladie de Crohn (CD). Les deux communications unifiées et de CD, lorsqu&#39;elles sont présentes dans le côlon, de générer un profil de symptômes similaires qui peuvent inclure la diarrhée, des saignements rectaux, des douleurs abdominales et la perte de poids. 1 Bien que la pathogénie des MICI reste inconnue, elle est décrite comme une maladie multifactorielle qui implique à la fois composantes génétiques et environnementales. 2 Il ya de nombreux modèles animaux et les variables de l&#39;inflammation du côlon qui ressemblent à plusieurs caractéristiques des MICI. Les modèles animaux de la plage de la colite de ceux qui naît spontanément dans les souches sensibles de certaines espèces à ceux nécessitant l&#39;administration de concentrations spécifiques de colite induisant des produits chimiques, tels que le dextran sulfate de sodium (DSS). Chimique induite par les modèles d&#39;inflammation intestinale sont les modèles les plus couramment utilisés et mieux décrit des MICI. Adminidémonstration de DSS dans l&#39;eau potable produit une colite aiguë ou chronique, selon le protocole d&#39;administration. 3 animaux ayant reçu du SSD présentent une perte de poids et les signes de selles molles ou diarrhée, parfois avec des preuves de saignement rectal 4,5. Ici, nous décrivons les méthodes par lesquelles développement de la colite et la réponse inflammatoire résultant peut être caractérisée après l&#39;administration de DSS. Ces méthodes comprennent l&#39;analyse histologique de l&#39;hématoxyline / éosine sections du côlon tachés, la mesure des cytokines pro-inflammatoires, et la détermination de la myéloperoxydase (MPO), qui peut être utilisé comme un marqueur de l&#39;inflammation. 6 L&#39;ampleur de la réponse inflammatoire dans la maladie de l&#39;Etat peut être évaluée par la présence de symptômes cliniques ou par l&#39;altération de l&#39;histologie dans le tissu muqueux. Côlon dommages histologiques est évaluée en utilisant un système de notation qui prend en compte la perte de l&#39;architecture crypte, l&#39;infiltration de cellules inflammatoires, des muscles tAbcès hickening, la déplétion des cellules caliciformes, et la crypte. 7 Quantitativement, les niveaux de cytokines pro-inflammatoires aiguës avec des propriétés inflammatoires, telles que l&#39;interleukine (IL)-1β, IL-6 et le facteur de nécrose tumorale (TNF)-α, peut être déterminée à l&#39;aide les méthodes classiques ELISA. En outre, l&#39;activité MPO peut être mesurée en utilisant un dosage colorimétrique et utilisé comme un indice d&#39;inflammation. 8 Dans la colite expérimentale, sévérité de la maladie est souvent corrélée avec une augmentation de l&#39;activité MPO et des niveaux élevés de cytokines pro-inflammatoires. Gravité de la colite et l&#39;inflammation associées aux dommages peuvent être évalués en examinant la consistance des selles et des saignements, en plus d&#39;évaluer l&#39;état histopathologique de l&#39;intestin à l&#39;aide d&#39;hématoxyline / éosine sections colorées des tissus du côlon. Fragments de tissus du côlon peut être utilisé pour déterminer l&#39;activité de MPO et de la production de cytokines. Pris ensemble, ces mesures peuvent être utilisées pour évaluer la réponse inflammatoire dans l&#39;intestindes modèles animaux de colite expérimentale.

Watch this Scientific Journal Video about Investigating Intestinal Inflammation in DSS-induced Model of IBD at JoVE.com

Investigating Intestinal Inflammation in DSS-induced Model of IBD

Des modèles expérimentaux de maladies inflammatoires de l&#39;intestin nous ont permis d&#39;examiner le complexe innée et adaptative des réponses immunitaires associées à la pathogenèse. Utiliser score histologique, la quantification des cytokines pro-inflammatoires et de l&#39;activité myéloperoxydase, on peut commencer à évaluer ces réponses observée dans la maladie intestinale inflammatoire.

Enquêter inflammation intestinale induite par DSS modèle des MICI

Inflammatory bowel disease (IBD) encompasses a range of intestinal pathologies, the most common of which are ulcerative colitis (UC) and Crohn's Disease ...

investigating-intestinal-inflammation-in-dss-induced-model-of-ibd

Research

JoVE Journal

Biology

66.7K vues.  McMaster University. Des modèles expérimentaux de maladies inflammatoires de l'intestin nous ont permis d'examiner le complexe innée et adaptative des réponses immunitaires associées à la pathogenèse. Utiliser score histologique, la quantification des cytokines pro-inflammatoires et de l'activité myéloperoxydase, on peut commencer à évaluer ces réponses observée dans la maladie intestinale inflammatoire.

Vidéo: Investigating Intestinal Inflammation in DSS-induced Model of IBD

Catheterization of Intestinal Loops in Ruminants

The intestine is a complex structure that is involved not only in absorption of nutrients, but also acts as a barrier between the individual and the outside world. As such, the intestine plays a pivotal role in immunosurveillance and protection from enteric pathogens. Investigating intestinal physiology and immunology commonly employs 'intestinal loops' as an experimental model. The majority of these loop models are non-recovery surgical procedures that study short-term (&lt;24 hr) changes in the intestine (1-3). We previously created a recovery intestinal loop model to specifically measure long-term (&lt;6 mo) immunological changes in the intestine of sheep following exposure to vaccines, adjuvants, and viruses (4). This procedure localized treatments to a specific 'loop', allowing us to sample this area of the intestine. A significant drawback of this method is the single window of opportunity to administer treatments (i.e. at the time of surgery). Furthermore, samples of both the intestinal mucosa and luminal contents can only be taken at the termination of the project. Other salient limitations of the above model are that the surgical manipulation and requisite post-operative measures (e.g. administration of antibiotics and analgesics) can directly affect the treatment itself and/or alter immune function, thereby confounding results. Therefore, we modified our intestinal loop model by inserting long-term catheters into the loops. Sheep recover fully from the procedure, and are unaffected by the exteriorized catheters. Notably, the establishment of catheters in loops allows us to introduce multiple treatments over an extended interval, following recovery from surgery and clearance of drugs administered during surgery and the post-operative period.

We describe a novel surgical method for catheterizing 'intestinal loops' within the ileum of sheep. Once animals have recovered from surgery and have cleared antibiotics and analgesics, multiple treatments can be deposited directly in loops via the catheters.

Cathétérisme des anses intestinales chez les ruminants

The intestine is a complex structure that is involved not only in absorption of nutrients, but also acts as a barrier between the individual and the ...

Recherche

Biologie

Rat Mesentery Exteriorization: A Model for Investigating the Cellular Dynamics Involved in Angiogenesis

Microvacular network growth and remodeling are critical aspects of wound healing, inflammation, diabetic retinopathy, tumor growth and other disease conditions1, 2. Network growth is commonly attributed to angiogenesis, defined as the growth of new vessels from pre-existing vessels. The angiogenic process is also directly linked to arteriogenesis, defined as the capillary acquisition of a perivascular cell coating and vessel enlargement. Needless to say, angiogenesis is complex and involves multiple players at the cellular and molecular level3. Understanding how a microvascular network grows requires identifying the spatial and temporal dynamics along the hierarchy of a network over the time course of angiogenesis. This information is critical for the development of therapies aimed at manipulating vessel growth.
The exteriorization model described in this article represents a simple, reproducible model for stimulating angiogenesis in the rat mesentery. It was adapted from wound-healing models in the rat mesentery4-7, and is an alternative to stimulate angiogenesis in the mesentery via i.p. injections of pro-angiogenic agents8, 9. The exteriorization model is attractive because it requires minimal surgical intervention and produces dramatic, reproducible increases in capillary sprouts, vascular area and vascular density over a relatively short time course in a tissue that allows for the two-dimensional visualization of entire microvascular networks down to single cell level. The stimulated growth reflects natural angiogenic responses in a physiological environment without interference of foreign angiogenic molecules. Using immunohistochemical labeling methods, this model has been proven extremely useful in identifying novel cellular events involved in angiogenesis. Investigators can readily correlate the angiogenic metrics during the time course of remodeling with time specific dynamics, such as cellular phenotypic changes or cellular interactions4, 5, 7, 10, 11.

This article describes a simple model for stimulating angiogenesis in the rat mesentery. The model produces dramatic increases in capillary sprouting, vascular area and vascular density over a relatively short time course in a tissue that allows en face visualization of entire microvascular networks down to the single cell level.

Extériorisation Mésentère Rat: Un modèle pour étudier la dynamique cellulaires impliqués dans l&#39;angiogenèse

Microvacular network growth and remodeling are critical aspects of wound healing, inflammation, diabetic retinopathy, tumor growth and other disease ...

A Protocol for Lentiviral Transduction and Downstream Analysis of Intestinal Organoids

Intestinal crypt-villus structures termed organoids, can be kept in sustained culture three dimensionally when supplemented with the appropriate growth factors. Since organoids are highly similar to the original tissue in terms of homeostatic stem cell differentiation, cell polarity and presence of all terminally differentiated cell types known to the adult intestinal epithelium, they serve as an essential resource in experimental research on the epithelium. The possibility to express transgenes or interfering RNA using lentiviral or retroviral vectors in organoids has increased opportunities for functional analysis of the intestinal epithelium and intestinal stem cells, surpassing traditional mouse transgenics in speed and cost. In the current video protocol we show how to utilize transduction of small intestinal organoids with lentiviral vectors illustrated by use of doxycylin inducible transgenes, or IPTG inducible short hairpin RNA for overexpression or gene knockdown. Furthermore, considering organoid culture yields minute cell counts that may even be reduced by experimental treatment, we explain how to process organoids for downstream analysis aimed at quantitative RT-PCR, RNA-microarray and immunohistochemistry. Techniques that enable transgene expression and gene knock down in intestinal organoids contribute to the research potential that these intestinal epithelial structures hold, establishing organoid culture as a new standard in cell culture.

In this video protocol we give a step by step explanation of lentiviral transduction in organoids of primary intestinal epithelium and of processing and downstream analysis of these cultures by quantitative RT-PCR, RNA-microarray and immunohistochemistry.

Un protocole pour Lentiviral transduction et analyse aval de intestinale organoïdes

Intestinal crypt-villus structures termed organoids, can be kept in sustained culture three dimensionally when supplemented with the appropriate growth ...

A Mouse Model of Intestinal Partial Obstruction

Intestinal obstructions, that impede or block peristaltic movement, can be caused by abdominal adhesions and most gastrointestinal (GI) diseases including tumorous growths. However, the cellular remodeling mechanisms involved in, and caused by, intestinal obstructions are poorly understood. Several animal models of intestinal obstructions have been developed, but the mouse model is the most cost/time effective. The mouse model uses the surgical implantation of an intestinal partial obstruction (PO) that has a high mortality rate if it is not performed correctly. In addition, mice receiving PO surgery fail to develop hypertrophy if an appropriate blockade is not used or not properly placed. Here, we describe a detailed protocol for PO surgery which produces reliable and reproducible intestinal obstructions with a very low mortality rate. This protocol utilizes a surgically placed silicone ring that surrounds the ileum which partially blocks digestive movement in the small intestine. The partial blockage makes the intestine become dilated due to the halt of digestive movement. The dilation of the intestine induces smooth muscle hypertrophy on the oral side of the ring that progressively develops over 2 weeks until it causes death. The surgical PO mouse model offers an in vivo model of hypertrophic intestinal tissue useful for studying pathological changes of intestinal cells including smooth muscle cells (SMC), interstitial cells of Cajal (ICC), PDGFR&#945;+, and neuronal cells during the development of intestinal obstruction.

Intestinal obstructions are a partial or complete blockage of the intestine that can cause severe abdominal pain, nausea, vomiting, and preventing the passage of stool. This procedure for creating intestinal partial obsructions in mice is reliable in studying the mechanisms underlying pathological cell growth and death in the intestine.

Un modèle de souris d’une Obstruction intestinale partielle

Intestinal obstructions, that impede or block peristaltic movement, can be caused by abdominal adhesions and most gastrointestinal (GI) diseases including ...

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.

Analyse de spectrométrie de masse pour identifier l’ubiquité de cenp-A marqué par EYFP (EYFP-CENP-A)

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

Organoid-Derived Epithelial Monolayer: A Clinically Relevant In Vitro Model for Intestinal Barrier Function

In the past, intestinal epithelial model systems were limited to transformed cell lines and primary tissue. These model systems have inherent limitations as the former do not faithfully represent original tissue physiology, and the availability of the latter is limited. Hence, their application hampers fundamental and drug development research. Adult stem-cell-based organoids (henceforth referred to as organoids) are miniatures of normal or diseased epithelial tissue from which they are derived. They can be established very efficiently from different gastrointestinal (GI) tract regions, have long-term expandability, and simulate tissue- and patient-specific responses to treatments in vitro. Here, the establishment of intestinal organoid-derived epithelial monolayers has been demonstrated along with methods to measure epithelial barrier integrity, permeability and transport,&#160;antimicrobial protein secretion, as well as histology. Moreover, intestinal organoid-derived monolayers can be enriched with proliferating stem and transit-amplifying cells as well as with key differentiated epithelial cells. Therefore, they represent a model system that can be tailored to study the effects of compounds on target cells and their mode of action. Although organoid cultures are technically more demanding than cell lines, once established, they can reduce failures in the later stages of drug development as they truly represent in vivo epithelium complexity and interpatient heterogeneity.

Here, we describe the preparation of human organoid-derived intestinal epithelial monolayers for studying intestinal barrier function, permeability, and transport. As organoids represent original epithelial tissue response to external stimuli, these models combine the advantages of expandability of cell lines and the relevance and complexity of primary tissue.

Monocouche épithéliale dérivée d’organoïdes : un modèle in vitro cliniquement pertinent pour la fonction de barrière intestinale

In the past, intestinal epithelial model systems were limited to transformed cell lines and primary tissue. These model systems have inherent limitations ...

Intestinal Epithelial Regeneration in Response to Ionizing Irradiation

The intestinal epithelium consists of a single layer of cells yet contains multiple types of terminally differentiated cells, which are generated by the active proliferation of intestinal stem cells located at the bottom of intestinal crypts. However, during events of acute intestinal injury, these active intestinal stem cells undergo cell death. Gamma irradiation is a widely used colorectal cancer treatment, which, while therapeutically efficacious, has the side effect of depleting the active stem cell pool. Indeed, patients frequently experience gastrointestinal radiation syndrome while undergoing radiotherapy, in part due to active stem cell depletion. The loss of active intestinal stem cells in intestinal crypts activates a pool of typically quiescent reserve intestinal stem cells and induces dedifferentiation of secretory and enterocyte precursor cells. If not for these cells, the intestinal epithelium would lack the ability to recover from radiotherapy and other such major tissue insults. New advances in lineage-tracing technologies allow tracking of the activation, differentiation, and migration of cells during regeneration and have been successfully employed for studying this in the gut. This study aims to depict a method for the analysis of cells within the mouse intestinal epithelium following radiation injury.

The gastrointestinal tract is one of the most sensitive organs to injury upon radiotherapeutic cancer treatments. It is simultaneously an organ system with one of the highest regenerative capacities following such insults. The presented protocol describes an efficient method to study the regenerative capacity of the intestinal epithelium.

Régénération épithéliale intestinale en réponse à une irradiation ionisante

The intestinal epithelium consists of a single layer of cells yet contains multiple types of terminally differentiated cells, which are generated by the ...

Effets épithéliaux de l’inflammation intestinale sur les coloïdes murins établis

Studying the Epithelial Effects of Intestinal Inflammation In Vitro on Established Murine Colonoids

The intestinal epithelium plays an essential role in human health, providing a barrier between the host and the external environment. This highly dynamic cell layer provides the first line of defense between microbial and immune populations and helps to modulate the intestinal immune response. Disruption of the epithelial barrier is a hallmark of inflammatory bowel disease (IBD) and is of interest for therapeutic targeting. The 3-dimensional colonoid culture system is an extremely useful in vitro model for studying intestinal stem cell dynamics and epithelial cell physiology in IBD pathogenesis. Ideally, establishing colonoids from the inflamed epithelial tissue of animals would be most beneficial in assessing the genetic and molecular influences on disease. However, we have shown that in vivo epithelial changes are not necessarily retained in colonoids established from mice with acute inflammation. To address this limitation, we have developed a protocol to treat colonoids with a cocktail of inflammatory mediators that are typically elevated during IBD. While this system can be applied ubiquitously to various culture conditions, this protocol emphasizes treatment on both differentiated colonoids and 2-dimensional monolayers derived from established colonoids. In a traditional culture setting, colonoids are enriched with intestinal stem cells, providing an ideal environment to study the stem cell niche. However, this system does not allow for an analysis of the features of intestinal physiology, such as barrier function. Further, traditional colonoids do not offer the opportunity to study the cellular response of terminally differentiated epithelial cells to proinflammatory stimuli. The methods presented here provide an alternative experimental framework to address these limitations. The 2-dimensional monolayer culture system also offers an opportunity for therapeutic drug screening ex vivo. This polarized layer of cells can be treated with inflammatory mediators on the basal side of the cell and concomitantly with putative therapeutics apically to determine their utility in IBD treatment.

Pleins feux sur l’auteur : Étude des effets épithéliaux de l’inflammation intestinale in vitro sur des coloïdes murins établis  

We describe a protocol detailing the isolation of murine colonic crypts for the development of 3-dimensional colonoids. The established colonoids can then be terminally differentiated to reflect the cellular composition of the host epithelium prior to receiving an inflammatory challenge or being directed to establish an epithelial monolayer.

Étude des effets épithéliaux de l’inflammation intestinale in vitro sur les colonoïdes murins établis

The intestinal epithelium plays an essential role in human health, providing a barrier between the host and the external environment. This highly dynamic ...