We would like to thank the members of the Reizes laboratory for their critical review and insights during preparation of the manuscript, as well as the Imaging and Histology cores at Lerner Research Institute for their assistance in data collection and data analysis. This work was supported through an internal grant funding through the Research Program Committee at Cleveland Clinic and by an external grant through the Society for Reproductive Investigation and Bayer. Research in the Reizes Laboratory is also funded through VeloSano Bike to Cure, Center of Research Excellence in Gynecologic Cancer, and through The Laura J. Fogarty Endowed Chair for Uterine Cancer Research. Cleveland Clinic owns the copyright permission for&#160;Figure 1&#160;and&#160;Figure 2.

NOTE: The use of animals in this study was approved by the Institutional Animal Care and Use Committee (IACUC) at the Cleveland Clinic Lerner Research Institute. All publicly available animal care and use standards were performed following guidelines by the National Institutes of Health.&#160;This procedure is utilizing aseptic techniques. The Petri dish is sterile. The PBS/saline used is sterile. The surgical instruments for necropsy and tissue dissection are sterilized via autoclave. We use 70% EtOH on the instruments ...

<ol>
	<li>Zondervan, K. T., Becker, C. M., Missmer, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endometriosis.">Endometriosis.</a> England Journal of Medicine. 382 (13), 1244-1256 (2020).</li><li>Schwartz, K., Llarena, N. C., Rehmer, J. M., Richards, E. G., Falcone, T. <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+pharmacotherapy+in+the+treatment+of+endometriosis+across+the+lifespan.">The role of pharmacotherapy in the treatment of endometriosis across the lifespan.</a> Expert Opinion on Pharmacotherapy. 21 (8), 893-903 (2020).</li><li>Giudice, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+practice.+Endometriosis.">Clinical practice. Endometriosis.</a> New England Journal of Medicine. 362 (25), 2389-2398 (2010).</li><li>D'Hooghe, T. M., Debrock, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endometriosis,+retrograde+menstruation+and+peritoneal+inflammation+in+women+and+in+baboons.">Endometriosis, retrograde menstruation and peritoneal inflammation in women and in baboons.</a> Human Reproduction Update. 8 (1), 84-88 (2002).</li><li>Ahn, S. H., 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=Pathophysiology+and+immune+dysfunction+in+endometriosis.">Pathophysiology and immune dysfunction in endometriosis.</a> BioMed Research International. 2015, (2015).</li><li>Falcone, T., Flyckt, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+management+of+endometriosis.">Clinical management of endometriosis.</a> Obstetrics and Gynecology. 131 (3), 557-571 (2018).</li><li>Vercellini, P., 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=Association+between+endometriosis+stage,+lesion+type,+patient+characteristics+and+severity+of+pelvic+pain+symptoms:+a+multivariate+analysis+of+over+1000+patients.">Association between endometriosis stage, lesion type, patient characteristics and severity of pelvic pain symptoms: a multivariate analysis of over 1000 patients.</a> Human Reproduction. 22 (1), 266-271 (2007).</li><li>Bulun, S. E., 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=Endometriosis.">Endometriosis.</a> Endocrine Reviews. 40 (4), 1048-1079 (2019).</li><li>Brueggmann, D., 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=Novel+three-dimensional+in+vitro+models+of+ovarian+endometriosis.">Novel three-dimensional in vitro models of ovarian endometriosis.</a> Journal of Ovarian Research. 7, 17 (2014).</li><li>Dodds, K. N., Beckett, E. A. H., Evans, S. F., Hutchinson, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lesion+development+is+modulated+by+the+natural+estrous+cycle+and+mouse+strain+in+a+minimally+invasive+model+of+endometriosis.">Lesion development is modulated by the natural estrous cycle and mouse strain in a minimally invasive model of endometriosis.</a> Biology of Reproduction. 97 (6), 810-821 (2017).</li><li>Martinez, J., Bisbal, V., Marin, N., Cano, A., G&#243;mez, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+monitoring+of+lesion+size+in+a+heterologous+mouse+model+of+endometriosis.">Noninvasive monitoring of lesion size in a heterologous mouse model of endometriosis.</a> Journal of Visualized Experiments: JoVE. (144), (2019).</li><li>Pelch, K. E., Sharpe-Timms, K. L., Nagel, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+model+of+surgically-induced+endometriosis+by+auto-transplantation+of+uterine+tissue.">Mouse model of surgically-induced endometriosis by auto-transplantation of uterine tissue.</a> Journal of Visualized Experiments: JoVE. (59), e3396 (2012).</li><li>Nishimoto-Kakiuchi, A., 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=Spontaneous+endometriosis+in+cynomolgus+monkeys+as+a+clinically+relevant+experimental+model.">Spontaneous endometriosis in cynomolgus monkeys as a clinically relevant experimental model.</a> Human Reproduction. 33 (7), 1228-1236 (2018).</li><li>Nair, H. 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=An+efficient+model+of+human+endometriosis+by+induced+unopposed+estrogenicity+in+baboons.">An efficient model of human endometriosis by induced unopposed estrogenicity in baboons.</a> Oncotarget. 7 (10), 10857-10869 (2016).</li><li>Lagan&#224;, A. S., 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=Translational+animal+models+for+endometriosis+research:+a+long+and+windy+road.">Translational animal models for endometriosis research: a long and windy road.</a> Annals of Translational Medicine. 6 (22), 431 (2018).</li><li>Bellofiore, 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=First+evidence+of+a+menstruating+rodent:+the+spiny+mouse+(Acomys+cahirinus).">First evidence of a menstruating rodent: the spiny mouse (Acomys cahirinus).</a> Amercian Journal of Obstetrics and Gynecology. 216 (1), 1-11 (2017).</li><li>Bruner-Tran, K. L., Mokshagundam, S., Herington, J. L., Ding, T., Osteen, K. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rodent+models+of+experimental+endometriosis:+identifying+mechanisms+of+disease+and+therapeutic+targets.">Rodent models of experimental endometriosis: identifying mechanisms of disease and therapeutic targets.</a> Current Women's Health Reviews. 14 (2), 173-188 (2018).</li><li>Bilotas, M. A., 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=Interplay+between+endometriosis+and+pregnancy+in+a+mouse+model.">Interplay between endometriosis and pregnancy in a mouse model.</a> PloS One. 10 (4), 0124900 (2015).</li><li>Peterse, D., 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=Of+mice+and+women:+a+laparoscopic+mouse+model+for+endometriosis.">Of mice and women: a laparoscopic mouse model for endometriosis.</a> Journal of Minimally Invasive Gynecology. 25 (4), 578-579 (2018).</li><li>Richards, E. G., 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=KLF11+is+an+epigenetic+mediator+of+DRD2/dopaminergic+signaling+in+endometriosis.">KLF11 is an epigenetic mediator of DRD2/dopaminergic signaling in endometriosis.</a> Reproductive Sciences. 224 (8), 1129-1138 (2017).</li><li>Jones, R. L., Lang, S. A., Kendziorski, J. A., Greene, A. D., Burns, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+a+Mouse+Model+of+Experimentally+Induced+Endometriosis+to+Evaluate+and+Compare+the+Effects+of+Bisphenol+A+and+Bisphenol+AF+Exposure.">Use of a Mouse Model of Experimentally Induced Endometriosis to Evaluate and Compare the Effects of Bisphenol A and Bisphenol AF Exposure.</a> Environmental Health Perspectives. 126 (12), 127004 (2018).</li><li>Greaves, E., 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+mouse+model+of+endometriosis+mimics+human+phenotype+and+reveals+insights+into+the+inflammatory+contribution+of+shed+endometrium.">A novel mouse model of endometriosis mimics human phenotype and reveals insights into the inflammatory contribution of shed endometrium.</a> The American Journal of Pathology. 184 (7), 1930-1939 (2014).</li><li>Nothnick, W. B., Graham, A., Holbert, J., Weiss, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miR-451+deficiency+is+associated+with+altered+endometrial+fibrinogen+alpha+chain+expression+and+reduced+endometriotic+implant+establishment+in+an+experimental+mouse+model.">miR-451 deficiency is associated with altered endometrial fibrinogen alpha chain expression and reduced endometriotic implant establishment in an experimental mouse model.</a> PloS One. 9 (6), 100336 (2014).</li></ol>

The authors have no conflicts of interest to disclose.

Our study demonstrates that endometriosis can be reliably induced in mice without requiring use of ovariectomy and/or survival surgery, and that ectopic endometrial lesions can be identified and quantified using a standardized survey of the abdomen and histologic analysis.
Many murine studies of endometriosis utilize surgically induced endometriosis in which donor endometrium is sutured in place to t...

Endometriosis is an enigmatic disease of the female reproductive tract with significant financial and health burdens on women1,2. The etiology of endometriosis is not completely understood, and multiple explanations have been proposed including coelomic metaplasia, embryonic M&#252;llerian rests, recruitment of bone marrow derived progenitor cells, and retrograde menstruation3. While multiple aspects of these proposed mechanisms may be involved, and no single explanation can account for all forms of the disease, the leading model of endometriosis pathogenesis is retrograde menstruation. Retrograde menstruation is the passage of menstrual effluent through the fallopian tubes and into the peritoneal cavity; it is estimated that 90% of menstruating women regularly undergo retrograde menstruation4,5. Given this commonplace phenomenon of retrograde menstruation, why endometriosis develops only in a subset of women is unclear5. To better understand the etiology of this disease, direct human studies are not feasible and animal studies are warranted.
Endometriosis is a challenge both to treat and to study. Prevalence of the disease is not known but estimated to be 10%1. While some advanced types of endometriosis may be accurately identified through noninvasive imaging, a definitive diagnosis is only achieved through histopathological analysis of surgically obtained biopsy specimens; lesions that visually appear to be diseased, may in fact be fibrosis or scarring from other causes6. Severity and extent of disease does not correlate with symptomatology7.
Endometriosis lesions consist of heterogeneous cell types and populations which interact in complex ways within the microenvironment, therefore, limiting the usefulness of cellular models8,9. In vivo models exist, but these have inherent challenges and limitations10,11,12. Primate models are ideal but are often not feasible13,14,15. Few non-primate mammals menstruate and develop endometriosis spontaneously16. Rodent models of endometriosis exist but each have limitations17. Many of these models require survival surgery to suture or implant endometrial tissue into the donor recipient wall or bowel, adding technical complexity, need for anesthesia, and confounding immune factors from the surgery itself18,19,20. In addition, many models require ovariectomy and estrogen supplementation; while increasing lesion yield, this adds time, expense, and additional survival surgery. Intraperitoneal (IP) injection models do not require anesthesia or survival surgery, and these models logically simulate retrograde menstruation better than suturing models21,22,23. Most IP models, however, are subject to more variability in lesion location due to the random dispersal of endometrial fragments following injection and therefore to more bias in lesion identification and measurement.
Here we present a murine model of endometriosis that integrates several features of existing endometriosis models into a novel, simplified, and efficient system that relies on microscopic quantification in lieu of subjective grading.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Supplies for injecting PMSG into donor mouse</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1 mL Tuberculin syringe with 27G needle</td>
			<td>Fisher Scientific</td>
			<td>14-826-87</td>
			<td></td>
		</tr>
		<tr>
			<td>Pregnant mare serum gonadotropin</td>
			<td>Sigma-Aldrich</td>
			<td>9002-70-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Supplies for necropsy of donor mouse and tissue processing</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>6&#8221; serrated forceps, curved tip</td>
			<td>Electron Microscopy Sciences</td>
			<td>72993-6C</td>
			<td></td>
		</tr>
		<tr>
			<td>70% ethanol solution</td>
			<td>Pharmco</td>
			<td>33000HPLCCS4L</td>
			<td>70% solution dilute ethyl acetate 200 proof</td>
		</tr>
		<tr>
			<td>Analytical balance</td>
			<td>Mettler Toledo</td>
			<td>ME54TE</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbon dioxide</td>
			<td>TriGas Supplier</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dissecting tray</td>
			<td>Fisher Scientific</td>
			<td>S14000</td>
			<td></td>
		</tr>
		<tr>
			<td>No. 10 disposable scalpel</td>
			<td>Fisher Scientific</td>
			<td>NC9999403</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissors, curved</td>
			<td>Electron Microscopy Sciences</td>
			<td>72941</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissors, straight</td>
			<td>Electron Microscopy Sciences</td>
			<td>72940</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereo microscope</td>
			<td>Leica Microsystems</td>
			<td>Leica SE 4</td>
			<td>For tissue dissection</td>
		</tr>
		<tr>
			<td>Sterile phosphate buffered saline (PBS)</td>
			<td>Institutional core facility supplies</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical instrument sterilization tray</td>
			<td>Electron Microscopy Sciences</td>
			<td>66112-02</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue culture dishes</td>
			<td>Fisher Scientific</td>
			<td>08-772E</td>
			<td></td>
		</tr>
		<tr>
			<td>Weighing dishes</td>
			<td>Fisher Scientific</td>
			<td>02-202-103</td>
			<td></td>
		</tr>
		<tr>
			<td>Supplies for injecting into recipient mouse</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1 cc syringe</td>
			<td>BD Biosciences</td>
			<td>301025</td>
			<td></td>
		</tr>
		<tr>
			<td>18 G needle</td>
			<td>Fisher Scientific</td>
			<td>148265d</td>
			<td></td>
		</tr>
		<tr>
			<td>200 uL pipette tip</td>
			<td>Fisher Scientific</td>
			<td>02-707-422</td>
			<td></td>
		</tr>
		<tr>
			<td>Double distilled water</td>
			<td>Institutional core facility supplies</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Latex bulb</td>
			<td>Fisher Scientific</td>
			<td>03-448-21</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro cover glass slip</td>
			<td>VWR</td>
			<td>48366-067</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope slide</td>
			<td>Fisher Scientific</td>
			<td>12-544-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Standard light microscope</td>
			<td>Leica Microsystems</td>
			<td>DM IL</td>
			<td>For evaluating vaginal cytology smears</td>
		</tr>
		<tr>
			<td>Supplies for harvesting tissue from recipient mouse</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>10% Buffered formalin</td>
			<td>Fisher Scientific</td>
			<td>SF100-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Biopsy foam pads</td>
			<td>Fisher Scientific</td>
			<td>22-038-222</td>
			<td></td>
		</tr>
		<tr>
			<td>Precision Digital Calipers</td>
			<td>Electron Microscopy Sciences</td>
			<td>62065-40</td>
			<td></td>
		</tr>
		<tr>
			<td>Processing/embedding cassettes</td>
			<td>Fisher Scientific</td>
			<td>22-272416</td>
			<td></td>
		</tr>
	</tbody>
</table>

a syngeneic murine model of endometriosis using naturally cycling mice

Endometriosis is a leading cause of pelvic pain and infertility. It is defined by the presence of endometrial tissue in extrauterine locations. The development of novel therapies and diagnostic tools for endometriosis has been limited due in part to challenges in studying the disease. Outside of primates, few mammals menstruate, and none develop spontaneous endometriosis. Rodent models are popular but require artificial induction of endometriosis, with many utilizing either immunocompromised mice or surgically induced disease. Recently, more attention has been given to models involving intraperitoneal injection. We present a murine model of endometriosis that integrates several features of existing endometriosis models into a novel, simplified system that relies on microscopic quantification in lieu of subjective grading. In this model, we perform hormonal stimulation of donor mice, intraperitoneal injection, systematic abdominal survey and tissue harvest, and histologic quantification that can be performed and verified at any time after necropsy. This model requires minimal resources and training; does not require expertise by lab technicians in murine survival surgery or in the identification of gross endometriotic lesions; can be used in immunocompromised, immunocompetent, and/or mutant mice; and reliably creates endometriotic lesions that are histologically consistent with human endometriotic disease.

For an initial proof of concept experiment, donor endometrium from RFP mice was injected into wildtype recipient mice. H&#38;E staining revealed histopathologic confirmation of classic architecture of endometriosis lesion (Figure 3A). Fluorescent microscopy confirmed that the observed lesion in question originated from the donor (Figure 3B).
The second experiment was performed using 10 wildtype C57BL/6J donors and 10 recipients. An ad...

Watch this Scientific Journal Video about A Syngeneic Murine Model of Endometriosis using Naturally Cycling Mice at JoVE.com

A Syngeneic Murine Model of Endometriosis using Naturally Cycling Mice

Many rodent models of endometriosis are limited by technical complexity, reproducibility, and/or need for immunocompromised animals or special reporter mice. We present a simplified system of lesion induction using any experimental mouse with an independently verifiable, objective scoring system and with no requirement for ovariectomy or survival surgery.

Endometriosis is a leading cause of pelvic pain and infertility. It is defined by the presence of endometrial tissue in extrauterine locations. The ...

Our mirroring model of endometriosis is a simplified and efficient system that integrates the best features of existing models. And perhaps most importantly, relies on microscopic quantification in lieu of subjective grading. Modeling endometriosis can be difficult because there can be many confounding factors and sources of bias.In our approach, endometriosis is induced without ovariectomy or survival surgery. And the endometrial lesions are objectively quantified. These Innovations provide a highly reliable and reproducible animal model of endometriosis that can be used to further endometriosis disease research.To facilitate ongoing estrous cycling, place urine soaked bedding from a male mouse cage into the recipient female mouse cage periodically throughout development, and again at 72 hours before endometrial tissue transplant. When the donor female mice are between 22 to 24 days old, use a one milliliter syringe equipped with a 25 to 27 gauge needle to subcutaneously inject two international units of pregnant mare serum gonadotropin in 200 microliters of sterile saline into the lower mouse abdomen. 38 to 42 hours after injection, use dissecting scissors to make a shallow transverse incision through the skin and subcutaneous tissue of the euthanized mouse at the midline and use blunt traction to open the skin on either side of the incision.Before removing the uterus, trim the adjacent connective tissue and transact each uterine horn just below its respective fallopian tubes, then transect the cervix to allow removal of the entire uterus and block. Inspect the uterus carefully, removing any additional peripheral fat or connective tissue and place the uterus in a droplet of cold PBS on a Petri dish for weighing. Transect each horn across the uterine fundus as close to the fundus as possible and place the dish under a dissecting microscope.Placing one blade of the dissecting scissors inside the lumen of the first horn, cut along the major axis of the tube keeping in mind, which side is this serosa and which side is the epithelium. Then use forceps to grasp and peel away the endometrial layer and mince the tissue into 10 to 12, one by one millimeter fragments. Alternatively, mince the tissue into one by one millimeter pieces without separating off the myometrium.Then place the tissues into 500 microliters of saline in a new Petri dish and harvest the endometrium from the second uterine horn as demonstrated. For peritoneal delivery of the tissue fragments into the recipient animal, use the blunt end of a one milliliter syringe to collect the tissue pieces. A total volume of one milliliter of tissue and saline should be collected.Attach an 18 gauge needle to the syringe and gently depress the plunger to load the fluid into the needle. A mock injection into the Petri dish can be performed to ensure that all of the tissue will pass through the needle tip. Either before or after the injection, use a bulb syringe to administer 10 microliters of saline to obtain a vaginal smear of the recipient animal for estrous cycle documentation.Holding the syringe at a 45 degree angle, intraperitoneally inject the fragments. If fragments remain after the injection, draw an additional 200 microliters of saline into the syringe to allow the rest of the pragmatists to be injected. Once you're assured of no bleeding or complications, place the mouse back in the home cage with a normal diet.Approximately 21 days after fragment injection, spray the recipient mouse abdomen was 70%ethanol, intent the skin to allow creation of a superficial subcutaneous incision to bluntly open the abdomen. Perform a complete survey of the abdominal wall and peritoneum, pancreas and mesenteric fat and para uterine connective fat and tissue for gross lesions. Harvest each region of tissue entirely and place the dissected tissue samples into an appropriate labeled cassette for formalin fixation and processing according to standard protocols.Then section the formalin blocks onto two slides per tissue area at two uniform depths. To score the endometriosis lesions, scan the tissue sections at a 40 times magnification and archive the slides. After scanning, use an appropriate digital slide reading software program to define and mark the longest distance between the edges of each endometriosis lesion.A continuous lesion is defined by glands surrounded by stroma. The line does not necessarily traverse only the endometriosis tissue, but the two end points must be connected by continuous stroma and or glands. Make a second line, 90 degrees across the first line as demonstrated.If multiple non-contiguous lesions are encountered, give each their own X and Y measurements. Calculate the final score for each slide as the summation of the areas of each lesion and use the larger of the scores from the two sections on each slide as the final score for that tissue region. Then total the scores from each region to give the final microscopic score for that animal.In this representative sample, histopathologic analysis after donor endometrium injection revealed a classic architecture of endometriosis lesion. Fluorescent microscopy of the tissue sample confirmed that the lesion originated from the donor. It is important to note that the macroscopic examination for lesions alone is not sufficient for the quantification of the endometriosis disease burden as the gross lesions observed in these representative samples were ultimately determined not to be endometriosis upon histological examination.Collection of all the tissue within the designated regions reduces bias by allowing for a systematic, objective approach to lesion quantification. Once this reliable and reproducible model has been achieved, researchers can use it to investigate a multitude of endometriosis pathways and therapies.

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4.7K vistas.  Cleveland Clinic. Our mirroring model of endometriosis is a simplified and efficient system that integrates the best features of existing models. And perhaps most importantly, relies on microscopic quantification in lieu of subjective grading. Modeling endometriosis can be difficult because there can be many confounding factors and sources of bias.In our approach, endometriosis is induced without ovariectomy or survival surgery. And the endometrial lesions are objectively quantified. These Innovations p...