Name: noninvasive monitoring of lesion size in a heterologous mouse model of endometriosis
Uploaded: 2019-02-26T13:00:00
Description: Watch this Scientific Journal Video about Noninvasive Monitoring of Lesion Size in a Heterologous Mouse Model of Endometriosis at JoVE.com

This work was supported by Spanish Ministry of Economy and Competitiveness through the Miguel Servet Program [CP13/00077] cofounded by FEDER (European Regional Development Fund) and awarded to Dr R. G&#243;mez as well as by Carlos III Institute of Health grants awarded to Dr R G&#243;mez [PI14/00547 and PI17/02329] and to Prof A. Cano [PI12/02582].

The use of human tissue specimens was approved by the Institutional Review Board and Ethics Committee of the Hospital Universitario La Fe. All patients provided written informed consent. The study involving animals was approved by the Institutional Animal Care Committee at the Centro de Investigacion Principe Felipe de Valencia, and all procedures were performed following the guidelines for the care and use of mammals from the National Institutes of Health.
1. Endometrial Tissue Collection and P...

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M., et al. <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+non-invasive+model+of+endometriosis+for+monitoring+the+efficacy+of+antiangiogenic+therapy.">A novel non-invasive model of endometriosis for monitoring the efficacy of antiangiogenic therapy.</a> The American Journal of Pathology. 168 (6), 2074-2084 (2006).</li><li>Laschke, M. W., Giebels, C., Nickels, R. M., Scheuer, C., Menger, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endothelial+progenitor+cells+contribute+to+the+vascularization+of+endometriotic+lesions.">Endothelial progenitor cells contribute to the vascularization of endometriotic lesions.</a> The American Journal of Pathology. 178 (1), 442-450 (2011).</li><li>Nap, A. 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C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prodrug+of+green+tea+epigallocatechin-3-gallate+(Pro-EGCG)+as+a+potent+anti-angiogenesis+agent+for+endometriosis+in+mice.">Prodrug of green tea epigallocatechin-3-gallate (Pro-EGCG) as a potent anti-angiogenesis agent for endometriosis in mice.</a> Angiogenesis. 16 (1), 59-69 (2013).</li><li>Delgado-Rosas, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+ergot+and+non-ergot-derived+dopamine+agonists+in+an+experimental+mouse+model+of+endometriosis.">The effects of ergot and non-ergot-derived dopamine agonists in an experimental mouse model of endometriosis.</a> Reproduction. 142 (5), 745-755 (2011).</li><li>Al-Jefout, M., Andreadis, N., Tokushige, N., Markham, R., Fraser, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+pilot+study+to+evaluate+the+relative+efficacy+of+endometrial+biopsy+and+full+curettage+in+making+a+diagnosis+of+endometriosis+by+the+detection+of+endometrial+nerve+fibers.">A pilot study to evaluate the relative efficacy of endometrial biopsy and full curettage in making a diagnosis of endometriosis by the detection of endometrial nerve fibers.</a> American Journal of Obstetrics &amp; Gynecology. 197 (6), 578 (2007).</li><li>Fortin, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+assessment+of+human+endometriotic+tissue+maintenance+and+regression+in+a+noninvasive+mouse+model+of+endometriosis.">Quantitative assessment of human endometriotic tissue maintenance and regression in a noninvasive mouse model of endometriosis.</a> Molecular Therapy. 9 (4), 540-547 (2004).</li><li>Liu, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+nude+mouse+models+for+green+fluorescence+human+endometriosis.">Improved nude mouse models for green fluorescence human endometriosis.</a> Journal of Obstetrics and Gynaecology Research. 36 (6), 1214-1221 (2010).</li><li>Wang, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+red+fluorescent+nude+mouse+model+of+human+endometriosis:+advantages+of+a+non-invasive+imaging+method.">A red fluorescent nude mouse model of human endometriosis: advantages of a non-invasive imaging method.</a> European Journal of Obstetric Gynecologic and Reproductive Biology. 176, 25-30 (2014).</li></ol>

The protocol herein detailed describes the implementation of an animal model of endometriosis in which the architecture of implanting lesions architecture is preserved whilst simultaneously allowing real time assessment of fluorescence emitted by mCherry labeled endometrial tissue. In this protocol, we describe the use of a specific in vivo imaging system and related software to non-invasively assess fluorescence emitted by the labeled lesion. Each user should adapt the protocol depending on the specific imaging device a...

Endometriosis is a chronic gynecologic disorder initiated by the implantation of the functional endometrium outside the uterine cavity. Ectopic lesions grow and induce inflammatory processes leading to chronic pelvic pain and infertility1. It is estimated that up to 10&#8211;15% of women of reproductive age are affected by endometriosis2, and it is present in approximately 40&#8211;50% of infertile women3. Current pharmacological treatments for endometriosis are unable to completely eradicate lesions and not free of side effects4,5. The research for more efficient therapies requires of the refinement of the existing animal models of endometriosis in such a way that human lesions can be appropriately mimicked, and the effects of compounds on lesion size among others can be closely assessed.
Primate models have been used to mimic endometriosis by implanting ectopic lesions histologically identical and at similar sites as in humans6,7,8; however, ethical concerns and the high economic costs related to experimentation with primates limit their use9. Consequently, the use of small animals, especially rodents, for the implementation of in-vivo models of endometriosis continues to be favored as it allows studies with larger numbers of individuals10,11. Endometriosis can be induced in these animals by transplanting either pieces of rodent uterine horns (&#34;homologous models&#34;)12,13 or human endometrial/endometriotic tissue to ectopic sites (heterologous models)14. In contrast to humans, rodents do not shed their endometrial tissue and thereby endometriosis can not be developed spontaneously in these species. Therefore, homologous mouse models of endometriosis have been criticized due to the fact that implanted ectopic mouse uterine tissue does not reflect the characteristics of human endometriotic lesions15.
Appropriate physiology of endometriosis can be mimicked in the heterologous models of endometriosis where fresh human endometrial fragments are implanted into immunodeficient animals. In conventional heterologous models, the therapeutic effects of compounds of interest are commonly assessed at the end point by the assessment of lesion size with the use of calipers16. An obvious limitation is that, as such, endpoint animal models do not allow studying implantation dynamics or endometriotic lesion development over time. An additional limitation is that the use of calipers does not allow accurate measurements of lesion size. Indeed, the standard error provided by calipers is in the same range (i.e., millimeters) as the size of the lesions implanted in mice, thus restricting the capacity of these tools to detect actual variations in size.
In order to overcome such limitations, herein, we describe the generation of a heterologous mouse model of endometriosis in which implanted human tissue is engineered to express a reporter m-Cherry fluorescent protein. Detection of the fluorescent signal with an appropriate image system enables non-invasive monitoring of lesion status with simultaneous quantification of its size in real time. Thus, our model provides clear advantages when compared to conventional endpoint models as it brings the opportunity of real-time non-invasive monitoring and the possibility to perform more objective and accurate estimation of variations in lesion size.

<table>
	<tbody>
		<tr>
			<td>Endosampler&#8482;</td>
			<td>Medgyn</td>
			<td>22720</td>
			<td>Cannula for sampling the uterine endometrium</td>
		</tr>
		<tr>
			<td>DMEM Medium</td>
			<td>VWR</td>
			<td>HYCLSH30285.FS</td>
			<td>Medium</td>
		</tr>
		<tr>
			<td>Ad-mCherry</td>
			<td>Vector Biolabs</td>
			<td>1767</td>
			<td>Adenoviral vector expressing mCherry</td>
		</tr>
		<tr>
			<td>PBS, 1X solution, sterile, pH 7,4</td>
			<td>VWR</td>
			<td>E504-500ML</td>
			<td>Buffer for washes</td>
		</tr>
		<tr>
			<td>Pellets 17-B-Estradiol 18 mg/ 60 days</td>
			<td>Innovative Research of America</td>
			<td>SE-121</td>
			<td>Hormone pellets for rodents</td>
		</tr>
		<tr>
			<td>Vetbond&#8482; Tissue Adhesive</td>
			<td>3M</td>
			<td>780-680</td>
			<td>Tissue adhesive</td>
		</tr>
		<tr>
			<td>Petri dishes in polystyrene crystal</td>
			<td>Levantina</td>
			<td>367-P101VR20</td>
			<td>Petri dishes</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomicin</td>
			<td>Sigma</td>
			<td>P4333-100ML</td>
			<td>Antibiotics</td>
		</tr>
		<tr>
			<td>Syringes, medical 10 ml 0,5 ml</td>
			<td>VWR</td>
			<td>CODA626616</td>
			<td>Syringes</td>
		</tr>
		<tr>
			<td>Nitrile gloves, powder-free</td>
			<td>VWR</td>
			<td>112-2754</td>
			<td>Gloves</td>
		</tr>
		<tr>
			<td>Soft swiss nude mice</td>
			<td>Charles River</td>
			<td>SNUSSFE05S</td>
			<td>Mice for animal experiment</td>
		</tr>
		<tr>
			<td>Ivis Spectrum In vivo Imaging system</td>
			<td>Perkin Elmer</td>
			<td>124262</td>
			<td>In vivo Monitoring equipment</td>
		</tr>
		<tr>
			<td>Living Image&#174; (Ivis software)</td>
			<td>Perkin Elmer</td>
			<td>---</td>
			<td>In vivo monitoring software</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Gibco</td>
			<td>10082147</td>
			<td>Enrichment serum</td>
		</tr>
		<tr>
			<td>96-well cell culture treated plates</td>
			<td>Life technologies</td>
			<td>167008</td>
			<td>Culture plates</td>
		</tr>
		<tr>
			<td>Urine flasks</td>
			<td>Summedical</td>
			<td>4004-248-001</td>
			<td>Flasks for washes</td>
		</tr>
		<tr>
			<td>Sterile surgical blades</td>
			<td>(Aesculap Division) Sanycare</td>
			<td>1609022-0008</td>
			<td>Surgical blades</td>
		</tr>
		<tr>
			<td>Isovet 1000 mg/g</td>
			<td>B-BRAUN</td>
			<td>---</td>
			<td>Isoflurane (Anesthetic)</td>
		</tr>
		<tr>
			<td>Buprex&#174; 0.3 mg</td>
			<td>Schering Plough S.A.</td>
			<td>---</td>
			<td>Buprenorphine (Analgesic solution)</td>
		</tr>
		<tr>
			<td>Injectable morphine solution 10 mg/mL</td>
			<td>B BRAUN</td>
			<td>---</td>
			<td>Morphine (Analgesic solution)</td>
		</tr>
		<tr>
			<td>Monofyl&#174; Absorbable Sutures</td>
			<td>COVIDIEN</td>
			<td>---</td>
			<td>Sutures</td>
		</tr>
		<tr>
			<td>Desinclor chlorhexidine</td>
			<td>Promedic SA</td>
			<td>---</td>
			<td>Antiseptic solution</td>
		</tr>
		<tr>
			<td>Microscopy DMi8</td>
			<td>Leica Mycrosystems</td>
			<td>---</td>
			<td>fluorescence microscope</td>
		</tr>
		<tr>
			<td>Hera Cell 150 Incubator</td>
			<td>Thermo Scientific</td>
			<td>51026282</td>
			<td>Incubator</td>
		</tr>
	</tbody>
</table>

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 describe the process for creating a heterologous model of endometriosis in which the architecture of lesions is preserved by implanting fluorescently labeled pieces of human endometrium into immunocompromised mice, thus allowing non-invasive monitoring of lesion progression. Labeling of endometrial fragments is achieved by infection with adenovirus engineered to express mCherry, a protein emitting fluorescence in the near infrared region. In Figure 1...

Watch this Scientific Journal Video about Noninvasive Monitoring of Lesion Size in a Heterologous Mouse Model of Endometriosis at JoVE.com

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

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 ...

This method can help answer key questions in evaluating therapeutic drug effects in the endometriosis field, such as the effects of anti-androgenic compounds on the size of endometriotic lesions. The main advantage of this technique is that the effects of the specific drugs can be assessed in animal models of endometriosis in real-time, rather than at the endpoint. Demonstrating the procedure will be Jessica Martinez, which is a technician from my lab, as well Viviana Bisbal and Nerea Marin, which are veterinarians from Centro de Investigacion Principe Felipe and which are close collaborators with our team.Two to three days before the implant surgery, transfer rinsed, healthy endometrial tissue biopsy fragments into a 10 centimeter Petri dish containing complete medium, and use scalpels to mince the tissue into five to 10 millimeter cubed pieces. Using a micropipette, add 30 to 50 microliter drops of DMEM across the bottom of a new 10 centimeter culture dish, leaving enough space between each drop so that they do not come into contact with each other. When all of the drops have been placed, use a syringe needle to place a single piece of biopsy tissue fragment into each drop.Next, add 100 to 200 microliters of freshly prepared adeno-mCherry to one well of a 96 well plate per tissue fragment, plus three wells with adenovirus free DMEM as a negative control. Then use the needle to transfer one tissue sample into each well of adeno-mCherry solution for an overnight incubation at 37 degrees celsius and 5%CO2. The next morning place the plate on a fluorescence microscope stage and use a 568 nanometer laser to check the fragments for an optimal labeling.Using the appropriate dilution of infecting mCherry adenovirus is key for an efficient labeling of the tissue. So to determine the appropriate concentration, several for mCherry dilution, for each individual experiment, have to be evaluated. Then transfer the most brilliant fragments into individual wells of a new 96 well plate containing fresh, complete medium.At least seven days after oophorectomy, decant the endometrial tissue fragments into a Petri dish, and confirm a lack of response to toe pinch in an anesthetized, oophorectomized animal. With the mouse in the supine position disinfect the ventral area and make a 1.5 centimeter longitudinal incision in the abdomen. Separate the skin from the muscle and make a second 1.5 centimeter incision in the muscle to access the peritoneal cavity.Holding the left edge of the abdominal muscular wall with mini-forceps, fold the muscle to expose the inner face of the peritoneum on the outside of the animal. Use mini-tweezers to briefly soak one endometrial implant in n-butyl ester cyanoacrylate adhesive and attach the fragment to the peritoneum. When the adhesive is dried, place a second implant on the contralateral side of the peritoneum as just demonstrated.Use an absorbable 6-0 suture to close the muscle layer and a non-absorbable 6-0 suture to close the skin. Then clean the skin incision with antiseptic solution and place the animal in the recovery zone with monitoring until full recumbency. For in-vivo fluorescent imaging of the implanted tissue fragments, 24 to 48 hours after the implantation surgery turn on the in-vivo imaging system, initialize the software, and allow the CCD camera to cool down for a few minutes.Once the instrument is ready place the first anesthetized mouse into the in-vivo imaging system cage, in the supine position, with the head inside a tubule connected to the anesthesia machine, and close the lid. Then click acquire and save the five resulting images. To quantify the in-vivo fluorescence, in the appropriate image analysis software click browse and select the unmixed file of interest to be analyzed.A new window will appear. Click add to list to include all of the unmixed files from each animal at different time points and click load as a group. All of the images should appear in a single sequence.In the tool palette window, unselect the individual scale checkbox to adjust all of the images to the same scale, and double click on one image of the sequence. To create a region of interest, in the region of interest tools select the contour and auto one options, and click on the circle shape to place the circle in the center of the fluorescent signal. Click create to create the region of interest and copy and paste the region of interest on a background where there is no signal.Then click measure regions of interest and select all to display values for the fluorescence intensity of each region and copy and paste these values into a spreadsheet. The labeling of the endometrial fragments is achieved by infection with adenovirus engineered to express mCherry, a protein that emits fluorescence in the near-infrared section that is significantly more robust than the non-infected endometrial tissue autofluorescence. During monitoring, in addition to the reference wavelength for mCherry, fluorescent images are taken with different pairs of excitation emission wavelength filters.To define the characteristic fluorescent tissue emission profiles of the lesions from the background, and autofluorescence emitted by the host tissues, the monitoring images containing raw fluorescence emitted by the animals during each time point are brought together, unnormalized, in a single file. Next, the fluorescence is unmixed, normalized, and represented as a false color image, and the regions of interests corresponding to specific legion and background signals are automatically recognized by the program and quantified. The background region of interest signaling is subtracted from the legion region of interest signaling.And the results of the intensity at each time point are normalized against the time point at which intensity is maximal. After several weeks of monitoring, the viable implants can be recovered for further downstream analysis. While attempting this procedure it's important to remember to select the concentration of Ad-mCherry that provides the most brilliant signal without compromising the viability of the tissue.Following this procedure, the lesions can be recovered and used to study additional distinctive parameters. This procedure is optimized for the non-invasive monitoring of xenograft human endometriosis lesions. However, it can be easily adapt for assessing the effects of a specific drugs of interest on the sites of a xenograft in real-time.

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In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish water and sediment. The choice of biological indicators must be based on reliable scientific knowledge and, possibly, on the availability of standardized procedures. In this article, we present a standardized protocol that used the marine crustacean Artemia to evaluate the toxicity of chemicals and/or of marine environmental matrices. Scientists propose that the brine shrimp (Artemia) is a suitable candidate for the development of a standard bioassay for worldwide utilization. A number of papers have been published on the toxic effects of various chemicals and toxicants on brine shrimp (Artemia). The major advantage of this crustacean for toxicity studies is the overall availability of the dry cysts; these can be immediately used in testing and difficult cultivation is not demanded1,2. Cyst-based toxicity assays are cheap, continuously available, simple and reliable and are thus an important answer to routine needs of toxicity screening, for industrial monitoring requirements or for regulatory purposes3. The proposed method involves the mortality as an endpoint. The numbers of survivors were counted and percentage of deaths were calculated. Larvae were considered dead if they did not exhibit any internal or external movement during several seconds of observation4. This procedure was standardized testing a reference substance (Sodium Dodecyl Sulfate); some results are reported in this work. This article accompanies a video that describes the performance of procedural toxicity testing, showing all the steps related to the protocol.

Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana

This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish ...

Validation of a Mouse Model to Disrupt LINC Complexes in a Cell-specific Manner

Nuclear migration and anchorage within developing and adult tissues relies heavily upon large macromolecular protein assemblies called LInkers of the Nucleoskeleton and Cytoskeleton (LINC complexes). These protein scaffolds span the nuclear envelope and connect the interior of the nucleus to components of the surrounding cytoplasmic cytoskeleton. LINC complexes consist of two evolutionary-conserved protein families, Sun proteins and Nesprins that harbor C-terminal molecular signature motifs called the SUN and KASH domains, respectively. Sun proteins are transmembrane proteins of the inner nuclear membrane whose N-terminal nucleoplasmic domain interacts with the nuclear lamina while their C-terminal SUN domains protrudes into the perinuclear space and interacts with the KASH domain of Nesprins. Canonical Nesprin isoforms have a variable sized N-terminus that projects into the cytoplasm and interacts with components of the cytoskeleton. This protocol describes the validation of a dominant-negative transgenic mouse strategy that disrupts endogenous SUN/KASH interactions in a cell-type specific manner. Our approach is based on the Cre/Lox system that bypasses many drawbacks such as perinatal lethality and cell nonautonomous phenotypes that are associated with germline models of LINC complex inactivation. For this reason, this model provides a useful tool to understand the role of LINC complexes during development and homeostasis in a wide array of tissues.

Nuclear envelope proteins play a central role in many basic biological processes and have been implicated in a variety of human diseases. This protocol describes a new Cre/Lox-based mouse model that allows for the spatiotemporal control of LINC complexes disruption.

Nuclear migration and anchorage within developing and adult tissues relies heavily upon large macromolecular protein assemblies called LInkers of the ...

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current blastocyst injection protocol. Here we report that a simple rotation of the embryo, and injection through Trans-Inner cell mass (TICM) increased the percentage of chimeric mice from 31% to 50%, with no additional equipment or further specialized training. 26 different inbred clones, and 35 total clones were injected over a period of 9 months. There was no significant difference in either pregnancy rate or recovery rate of embryos between traditional injection techniques and TICM. Therefore, without any major alteration in the injection process and a simple positioning of the blastocyst and injecting through the ICM, releasing the ES cells into the blastocoel cavity can potentially improve the quantity of chimeric production and subsequent germline transmission.

Here we present a protocol to increase chimera production without the use of new equipment. A simple orientation change of the embryo for injection can increase the number of embryos produced, and potentially reduce the timeline to germline transmission.

In an effort to increase efficiency in the creation of genetically modified mice via ES Cell methodologies, we present an adaptation to the current ...

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 ...

Visualization of Replisome Encounters with an Antigen Tagged Blocking Lesion

Considerable insight is present into the cellular response to double strand breaks (DSBs), induced by nucleases, radiation, and other DNA breakers. In part, this reflects the availability of methods for the identification of break sites, and characterization of factors recruited to DSBs at those sequences. However, DSBs also appear as intermediates during the processing of DNA adducts formed by compounds that do not directly cause breaks, and do not react at specific sequence sites. Consequently, for most of these agents, technologies that permit the analysis of binding interactions with response factors and repair proteins are unknown. For example, DNA interstrand crosslinks (ICLs) can provoke breaks following replication fork encounters. Although formed by drugs widely used as cancer chemotherapeutics, there has been no methodology for monitoring their interactions with replication proteins.
Here, we describe our strategy for following the cellular response to fork collisions with these challenging adducts. We linked a steroid antigen to psoralen, which forms photoactivation dependent ICLs in nuclei of living cells. The ICLs were visualized by immunofluorescence against the antigen tag. The tag can also be a partner in the Proximity Ligation Assay (PLA) which reports the close association of two antigens. The PLA was exploited to distinguish proteins that were closely associated with the tagged ICLs from those that were not. It was possible to define replisome proteins that were retained after encounters with ICLs and identify others that were lost. This approach is applicable to any structure or DNA adduct that can be detected immunologically.

While replication fork collisions with DNA adducts can induce double strand breaks, less is known about the interaction between replisomes and blocking lesions. We have employed the proximity ligation assay to visualize these encounters and to characterize the consequences for replisome composition.

Considerable insight is present into the cellular response to double strand breaks (DSBs), induced by nucleases, radiation, and other DNA breakers. In ...

A Mouse Model of Lumbar Spine Instability

Intervertebral disc degeneration (IDD) is a common pathological change leading to low back pain. Appropriate animal models are desired for understanding the pathological processes and evaluating new drugs. Here, we introduced a surgically induced lumbar spine instability (LSI) mouse model that develops IDD starting from 1 week post operation. In detail, the mouse under anesthesia was operated by low back skin incision, L3&#8211;L5 spinous processes exposure, detachment of paraspinous muscles, resection of processes and ligaments, and skin closure. L4&#8211;L5 IVDs were chosen for the observation. The LSI model develops lumbar IDD by porosity and hypertrophy in endplates at an early stage, decrease in intervertebral disc volume, shrinkage in nucleus pulposus at an intermediate stage, and bone loss in lumbar vertebrae (L5) at a later stage. The LSI mouse model has the advantages of strong operability, no requirement of special equipment, reproducibility, inexpensive, and relatively short period of IDD development. However, LSI operation is still a trauma that causes inflammation within the first week post operation. Thus, this animal model is suitable for study of lumbar IDD.

We developed a lumbar intervertebral disc degeneration mouse model by resection of L3&#8211;L5 spinous processes along with supra- and inter-spinous ligaments and detachment of paraspinous muscles.

Intervertebral disc degeneration (IDD) is a common pathological change leading to low back pain. Appropriate animal models are desired for understanding ...

Monitoring Dynamic Growth of Retinal Vessels in Oxygen-Induced Retinopathy Mouse Model

Oxygen-induced retinopathy (OIR) is widely used to study abnormal vessel growth in ischemic retinal diseases, including retinopathy of prematurity (ROP), proliferative diabetic retinopathy (PDR), and retinal vein occlusion (RVO). Most OIR studies observe retinal neovascularization at specific time points; however, the dynamic vessel growth in live mice along a time course, which is essential for understanding the OIR-related vessel diseases, has been understudied. Here, we describe a step-by-step protocol for the induction of the OIR mouse model, highlighting the potential pitfalls, and providing an improved method to quickly quantify areas of vaso-obliteration (VO) and neovascularization (NV) using immunofluorescence staining. More importantly, we monitored vessel regrowth in live mice from P15 to P25 by performing fluorescein fundus angiography (FFA) in the OIR mouse model. The application of FFA to the OIR mouse model allows us to observe the remodeling process during vessel regrowth.

This protocol describes a detailed method for the preparation and immunofluorescence staining of mice retinal flat mounts and analysis. The use of fluorescein fundus angiography (FFA) for mice pups and image processing are described in detail as well.

Oxygen-induced retinopathy (OIR) is widely used to study abnormal vessel growth in ischemic retinal diseases, including retinopathy of prematurity (ROP), ...

Bioluminescent Monitoring of Graft Survival in an Adoptive Transfer Model of Autoimmune Diabetes in Mice

Type 1 diabetes is characterized by the autoimmune destruction of the insulin-producing beta cells of the pancreas. A promising treatment for this disease is the transplantation of stem cell-derived beta cells. Genetic modifications, however, may be necessary to protect the transplanted cells from persistent autoimmunity. Diabetic mouse models are a useful tool for the preliminary evaluation of strategies to protect transplanted cells from autoimmune attack. Described here is a minimally invasive method for transplanting and imaging cell grafts in an adoptive transfer model of diabetes in mice. In this protocol, cells from the murine pancreatic beta cell line NIT-1 expressing the firefly luciferase transgene luc2 are transplanted subcutaneously into immunodeficient non-obese diabetic (NOD)-severe combined immunodeficient (scid) mice. These mice are simultaneously injected intravenously with splenocytes from spontaneously diabetic NOD mice to transfer autoimmunity. The grafts are imaged at regular intervals via non-invasive bioluminescent imaging to monitor the cell survival. The survival of mutant cells is compared to that of control cells transplanted into the same mouse.

This protocol describes a straightforward and minimally invasive method for transplanting and imaging NIT-1 cells in non-obese diabetic (NOD)-severe combined immunodeficient mice challenged with splenocytes purified from spontaneously diabetic NOD mice.

Type 1 diabetes is characterized by the autoimmune destruction of the insulin-producing beta cells of the pancreas. A promising treatment for this disease ...