Name: investigating intestinal inflammation in dss-induced model of ibd
Uploaded: 2012-02-01T13:00:00
Description: Watch this Scientific Journal Video about Investigating Intestinal Inflammation in DSS-induced Model of IBD at JoVE.com

This work is supported by grants from Canadian Institutes of Health Research (CIHR) and by Crohn's and Colitis Foundation of Canada (CCFC).

1. Murine model of DSS-induced acute colitis
<ol>
	<li>Add dextran sulphate sodium (DSS) to autoclaved drinking water to the desired final concentration (1-5%) (wt/vol) (i.e. To make a 5% DSS solution, add 25 g of DSS powder to 500 mL of autoclaved water). Stock solution can be left at room temperature for up to one week or at 4&deg;C until use.</li>
	<li>In a biosafety hood, pour stock DSS solution into 50 mL Falcon tubes (one needed per cage). Keep the stock solution to refill tubes when needed.</li>
	<li>Replace dri...

<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>

DSS colitis is a widely used chemically induced model of intestinal inflammation. In this model, mice are given drinking water supplemented with DSS, which is thought to be toxic to gut epithelial cells and disrupt the integrity of the mucosal barrier.10 Administration of DSS induces an acute colitis that is characterized by loose stool, fecal bleeding, and infiltration with granulocytes.10 During DSS administration, colitis is usually associated with significant weight loss and presence of blood in...

<table border="1">
<tbody>
 <tr>
 <td>Name of reagent/equipment:</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments </td>
 </tr>
 <tr>
 <td>Eppendorf Safe-Lock Microcentrifuge Tube (2mL)</td>
 <td>eppendorf</td>
 <td>0030 120.094</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Biotek EL808 Absorbance plate reader </td>
 <td>Biotek </td>
 <td>EL808 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Dextran sulphate sodium salt reagent grade (molecular weight 36,000-50,000 Da)</td>
 <td>MP Biomedicals</td>
 <td>160110</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Gen5 (software)</td>
 <td>Biotek</td>
 <td>Version 1.10.8</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Hexadecyltrimethylammonium bromide (HTAB)</td>
 <td>Sigma-Aldrich</td>
 <td>H5882-100G</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Hydrogen peroxide, 30 wt.% solution in water</td>
 <td>Sigma-Aldrich</td>
 <td>216763</td>
 <td>Store at 2-8&deg;C</td>
 </tr>
 <tr>
 <td>Microtest plate 96-well flat bottom</td>
 <td>Sarstedt</td>
 <td>82.1581</td>
 <td>For single use only</td>
 </tr>
 <tr>
 <td>o-Dianisidine</td>
 <td>Sigma-Aldrich</td>
 <td>D-3252</td>
 <td>Light sensitive. Store at 2-8&deg;C</td>
 </tr>
 <tr>
 <td>Potassium phosphate, dibasic</td>
 <td>Caledon</td>
 <td>6620-1</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Potassium phosphate, monobasic</td>
 <td>EMD Chemicals</td>
 <td>PX1565-1</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Protease inhibitor cocktail</td>
 <td>Sigma-Aldrich </td>
 <td>P8340</td>
 <td>Store at -20&deg;C</td>
 </tr>
 <tr>
 <td>Triton X-100</td>
 <td>Sigma-Aldrich</td>
 <td>T8787</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Tungsten Carbide beads for Tissue Lyser II</td>
 <td>QUIAGEN</td>
 <td>69997</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
</table>

investigating intestinal inflammation in dss-induced model of ibd

Inflammatory bowel disease (IBD) encompasses a range of intestinal pathologies, the most common of which are ulcerative colitis (UC) and Crohn's Disease (CD). Both UC and CD, when present in the colon, generate a similar symptom profile which can include diarrhea, rectal bleeding, abdominal pain, and weight loss.1 Although the pathogenesis of IBD remains unknown, it is described as a multifactorial disease that involves both genetic and environmental components.2
There are numerous and variable animal models of colonic inflammation that resemble several features of IBD. Animal models of colitis range from those arising spontaneously in susceptible strains of certain species to those requiring administration of specific concentrations of colitis-inducing chemicals, such as dextran sulphate sodium (DSS). Chemical-induced models of gut inflammation are the most commonly used and best described models of IBD. Administration of DSS in drinking water produces acute or chronic colitis depending on the administration protocol.3 Animals given DSS exhibit weight loss and signs of loose stool or diarrhea, sometimes with evidence of rectal bleeding.4,5 Here, we describe the methods by which colitis development and the resulting inflammatory response can be characterized following administration of DSS. These methods include histological analysis of hematoxylin/eosin stained colon sections, measurement of pro-inflammatory cytokines, and determination of myeloperoxidase (MPO) activity, which can be used as a surrogate marker of inflammation.6
The extent of the inflammatory response in disease state can be assessed by the presence of clinical symptoms or by alteration in histology in mucosal tissue. Colonic histological damage is assessed by using a scoring system that considers loss of crypt architecture, inflammatory cell infiltration, muscle thickening, goblet cell depletion, and crypt abscess.7 Quantitatively, levels of pro-inflammatory cytokines with acute inflammatory properties, such as interleukin (IL)-1&beta;, IL-6 and tumour necrosis factor (TNF)-&alpha;,can be determined using conventional ELISA methods. In addition, MPO activity can be measured using a colorimetric assay and used as an index of inflammation.8
In experimental colitis, disease severity is often correlated with an increase in MPO activity and higher levels of pro-inflammatory cytokines. Colitis severity and inflammation-associated damage can be assessed by examining stool consistency and bleeding, in addition to assessing the histopathological state of the intestine using hematoxylin/eosin stained colonic tissue sections. Colonic tissue fragments can be used to determine MPO activity and cytokine production. Taken together, these measures can be used to evaluate the intestinal inflammatory response in animal models of experimental colitis.

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

Experimental models of inflammatory bowel disease have allowed us to examine the complex innate and adaptive immune responses associated with pathogenesis. Using histological scoring, quantification of pro-inflammatory cytokines and myeloperoxidase activity, one can begin to assess these responses seen in inflammatory bowel disease.

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

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Biology

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.

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 ...

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.

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.

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.

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.

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.

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.

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

Epithelial Effects of Intestinal Inflammation on Established Murine Colonoids

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.

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

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.

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

Construction of a 3D Intestinal Mucosa Model with Paraffin Embedding

Basic Three-Dimensional (3D) Intestinal Model System with an Immune Component

There has been an increase in the use of in vivo and in vitro intestinal models to study the pathophysiology of inflammatory intestinal diseases, for the pharmacological screening of potentially beneficial substances, and for toxicity studies on potentially harmful food components. Of relevance, there is a current demand for the development of cell-based in vitro models to substitute animal models. Here, a protocol for a basic, &#8220;healthy tissue&#8221; three-dimensional (3D) intestinal equivalent model using cell lines is presented with the dual benefit of providing both experimental simplicity (standardized and easily repeatable system) and physiological complexity (Caco-2 enterocytes with a supporting immune component of U937 monocytes and L929 fibroblasts). The protocol also includes paraffin embedding for light microscopic evaluation of fixed intestinal equivalents, thereby providing the advantage of analyzing multiple visual parameters from a single experiment. Hematoxylin and eosin (H&#38;E) stained sections showing the Caco-2 columnar cells forming a tight and regular monolayer in control treatments are used to verify the efficacy of the model as an experimental system. Using gluten as a pro-inflammatory food component, parameters analyzed from sections include reduced monolayer thickness, as well as disruption and detachment from the underlying matrix (H&#38;E), decreased tight junction protein expression as shown from occludin staining (quantifiable statistically), and immune-activation of migrating U937 cells as evidenced from the cluster of differentiation 14 (CD14) staining and CD11b-related differentiation into macrophages. As shown by using lipopolysaccharide to simulate intestinal inflammation, additional parameters that can be measured are increased mucus staining and cytokine expression (such as midkine) that can be extracted from the medium prior to fixation. The basic three-dimensional (3D) intestinal mucosa model and fixed sections can be recommended for inflammatory status and barrier integrity studies with the possibility of analyzing multiple visual quantifiable parameters.

Author Spotlight: Investigating the Effects of Compounds on Intestinal Tissue Using 3D Human Cell Line Models 

Here we describe constructing a basic three-dimensional (3D) intestinal cell line model system and a paraffin embedding protocol for light microscopic evaluation of fixed intestinal equivalents. Staining of selected proteins permits the analysis of multiple visual parameters from a single experiment for potential use in preclinical drug screening studies.

There has been an increase in the use of in vivo and in vitro intestinal models to study the pathophysiology of inflammatory intestinal diseases, for the ...

Laser Induced Thermoplasmonic Puncture for the Study of Plasma Membrane Repair

A Thermoplasmonic Approach for Investigating Plasma Membrane Repair in Living Cells and Model Membranes

The cell membrane is crucial for cell survival, and ensuring its integrity is essential as the cell experiences injuries throughout its entire life cycle. To prevent damage to the membrane, cells have developed efficient plasma membrane repair mechanisms. These&#160;repair mechanisms can be studied by combining confocal microscopy and nanoscale thermoplasmonics to identify and investigate the role of key proteins, such as annexins, involved in surface repair in living cells and membrane model systems.
The puncturing method employs a laser to induce highly localized heating upon nanoparticle irradiation. The use of near-infrared light minimizes phototoxicity in the biological sample, while the majority of the absorption takes place in the near-infrared resonant plasmonic nanoparticle. This thermoplasmonic method has been exploited for potential photothermal and biophysical research to enhance the understanding of intracellular mechanisms and cellular responses through vesicle and cell fusion studies. The approach has shown to be complementary to existing methods for membrane disruption, such as mechanically, chemically, or optically induced injuries, and provides a high level of control by inflicting extremely localized injuries. The extent of the injury is limited to the vicinity of the spherical nanoparticle, and no detrimental damage occurs along the beam path as opposed to pulsed lasers using different wavelengths. Despite certain limitations, such as the formation of nanobubbles, the thermoplasmonic method offers a unique tool for investigating cellular responses in plasma membrane repair in an almost native environment without compromising cell viability.
When integrated with confocal microscopy, the puncturing method can provide a mechanistic understanding of membrane dynamics in model membrane systems as well as quantitative information on protein responses to membrane damage, including protein recruitment and their biophysical function. Overall, the application of this method to reduced model systems can enhance our understanding of the intricate plasma membrane repair machinery in living cells.

Author Spotlight: Exploring Plasma Membrane Repair Mechanisms with Innovative Thermoplasmonic Puncturing 

The thermoplasmonic puncture method integrates confocal microscopy, optical tweezers, and gold nanoparticles to study protein responses during plasma membrane repair in cells and giant unilamellar vesicles. The technique enables rapid and localized membrane puncture, allowing the identification of key proteins and their functional roles in the intricate plasma membrane repair machinery.

The cell membrane is crucial for cell survival, and ensuring its integrity is essential as the cell experiences injuries throughout its entire life cycle. ...