MAK acknowledges support for this work from the National Institutes of Health / National Cancer Institute grant number - 1R15CA152985-01A1. This project has also been supported by the Miami University Undergraduate Research Award Program, the Miami University Doctorate-Undergraduate Opportunities for Scholarship Program and the Miami University Summer Scholars Program.

The procedures carried out in the video and described below have been approved by the Institutional Animal Care and Use Committee (IACUC) at Miami University.
1. Preparation and Stimulus Test
<ol>
	<li>Establish two distinct areas for the surgical procedure, the operating table and the post-operation table. Stage both areas with all materials and utensils necessary.
	<ol>
		<li>Stage the operating table under a vented hood. Arrange the table with the equipment in a manner that allows the continuous and unimpeded performance of the procedure.</li>
		<li>Establish a postoperative table in the same room and near the main table of operation. Maintain both tables as sterile environments throughout the procedure.</li>
	</ol>
	</li>
	<li>Place the following supplies on the operating table: one glass jar with lid, one 15 mL tube, one pair of surgical scissors, one squeeze bottle of 70% ethanol, two foam boards, two forceps, two 1 mL 21 gauge syringes, two 50 mL tubes, one centrifuge tube, one cryogenic vial, four surgical pads, ten pins, a dispenser of sterilizing wipes, and a sharps container.</li>
	<li>Place the following supplies on the post-operation table: one analytical balance, one 4 L dewar of liquid nitrogen, a shallow wide mouth dewar, a floating microtube rack, one pair of surgical scissors, two forceps, four cryogenic vials, and a dispenser of sterile wipes.</li>
	<li>Fill one 50 mL and one 15 mL tube to 75% volume with formalin.</li>
	<li>Using a pin in each corner, affix one surgical pad to an approximate 30 cm x 30 cm foam board to serve as the dissection board. Use the remaining four pins during the operation. Prepare a smaller foam board with a surgical pad to transfer the organs to the post-op table. 
	CAUTION: Isoflurane (99.9%) is a toxic chemical, and should be used in a vent hood to ensure the maximum level of safety from the scavenging of waste anesthetic gas8. Additional information regarding the risks to researchers associated with the use of the open-drop method using isoflurane can be found in an article by Taylor and Mook8.</li>
	<li>Place one surgical pad into the glass jar and soak with a few drops of isoflurane (99.9%) and place a paper towel over the top to prevent direct contact of the mouse with the isoflurane. Similarly, use a surgical pad to line the remaining tube and soak with a few drops of isoflurane and place an additional pad over the top to prevent direct contact between the mouse and the isoflurane.</li>
	<li>Pour liquid nitrogen into the shallow wide mouth dewar until the maximum fill line is reached.</li>
	<li>Place the mouse selected for dissection into the anesthesia chamber, i.e. the glass jar with a pad soaked with a few drops of isoflurane (99.9%) covered with the lid, for ~1 min. 
	NOTE: This time varies from mouse to mouse. Once the mouse is unconscious, remove it from the chamber and place it onto the operating board.</li>
	<li>Orient the mouse so that it is lying ventral side up and with its head pointed away from the scientist. Place the head inside the tube lined with a surgical pad soaked with a few drops of isoflurane (99.9%), and perform a stimulus test by a foot pinch to ensure that the mouse is unresponsive to stimuli.
	<ol>
		<li>If this test fails and the mouse responds to the foot pinch test, repeat step 1.8.</li>
	</ol>
	</li>
</ol>
2. Initial Incision, Heart Puncture, and Euthanasia
<ol>
	<li>Pin the limbs of the mouse to the surgical foam board and wet the ventral side of the mouse with 70% ethanol.</li>
	<li>Pinch the fur/skin near the urethral opening with forceps and pull slightly upwards. Make an incision with the surgical scissors through the abdominal cavity starting from the urethral opening, up the midline and ending at the chin.
	<ol>
		<li>Near the starting point of the initial incision, grab one side of the fur/skin with the forceps and make another incision with the scissors downward and diagonally towards the back paw.</li>
		<li>Repeat this in the same manner on the opposite side. 
		NOTE: The fur/skin may be pinned down to create a wider opening, but is not necessary.</li>
	</ol>
	</li>
	<li>Locate the heart and remove the pericardium, which is the sac around the heart, to avoid clogging of the syringe needle.
	<ol>
		<li>Grasp the pericardium with the forceps and cut it with the scissors. Perform the heart puncture by carefully inserting the syringe needle into the beating heart and slowly start to retract the plunger.</li>
		<li>For optimal blood collection, use the plunger of the needle to mimic the pumping action of the heart and avoid drawing too quickly. 
		NOTE: Typically about 1 mL of blood can be collected.</li>
		<li>After completing the blood collection, dispel the blood into the centrifuge tube and dispose of the syringe into the sharps container.</li>
		<li>After the heart puncture is performed, carry out euthanasia by removing the attachments connecting the heart. 
		NOTE: Heparin, an anti-coagulant, was not added to the syringe in this procedure prior to the heart puncture to allow the blood to coagulate for serum collection in this specific study. However, if the researcher wanted to prevent blood coagulation to collect plasma, heparin could be added to the syringe prior to the heart puncture.</li>
	</ol>
	</li>
	<li>If the study involves genotyping of the mouse, snip a portion of the ear with the scissors and place into a centrifuge tube for a genotype verification.</li>
</ol>
3. Pancreas Extraction
<ol>
	<li>Locate the stomach on the left side of the mouse. Begin gently (so as to avoid tearing) separating the pancreas from the stomach and duodenum by using two forceps. 
	NOTE: When detaching the pancreas from the stomach and intestines, it is very important that the forceps are used gently to guide the pancreas tissue away from the organs and to not crush or tear the pancreas with the forceps.
	<ol>
		<li>Continue to separate the pancreas from the small intestine jejunum and ileum sections, and lastly from the caecum of the large intestine.</li>
	</ol>
	</li>
	<li>At the caecum, reposition the forceps and continue separation of the pancreas along the remaining colon towards the rectum. 
	NOTE: At this point, it is convenient to cut and remove the portion from the stomach to the region of the colon immediately preceding the rectum.</li>
	<li>Locate the pancreas and attached spleen. Slide the pancreas towards the right side of the mouse. Separate the remaining connections between the pancreas and thoracic cavity with the forceps to fully detach the pancreas and adjoined spleen.</li>
	<li>Remove the pancreas and spread it out for examination. Leave the spleen attached to the pancreas for identification purposes.
	<ol>
		<li>Remove all connective tissue, fat and mesenteric tissue from the pancreas. 
		NOTE: This tissue is whiter in color and thus can be easily distinguished from the pancreas tissue that is pinker in color. This is particularly important if the whole pancreas needs to be removed. For example, if the pancreas needs to be weighed and compared to body weight or between groups of animals. In the Ptf1acre/+;LSL-KrasG12D/+ mouse model, specifically in the older months, hard fibrous pancreatic tissue could be present. In this case, careful removal of the pancreas must be conducted as the intestines could be interlaced in tumor tissue. In advanced cases, abnormal spleen and liver tissue may also be present.</li>
	</ol>
	</li>
	<li>If desired, remove other organs at this point.</li>
</ol>
4. Data Collection and Storage
<ol>
	<li>After extraction of the organs, move the samples to the postoperative area for preservation.</li>
	<li>Weigh each organ and place them into their respective cryogenic vial. 
	NOTE: Along with the mass of each sample, any irregularities should be recorded for future reference.</li>
	<li>Once the organs are weighed, place them into the liquid nitrogen for snap freezing.</li>
	<li>After snap freezing, store the organs at -80 &#176;C for long-term storage.</li>
	<li>Place the formalin stored samples on the bench top overnight, and the next morning change their solution from formalin to 70% ethanol. 
	NOTE: These samples should be stored at 4 &#176;C for long-term storage.</li>
	<li>For long term storage, freeze the blood and ear punch at -80 &#176;C.. For serum collection from the blood, allow the blood to coagulate for 30 min then centrifuge it. Remove the serum portion using a pipette and then store at -80 &#176;C.</li>
</ol>
5. Clean Up
<ol>
	<li>Sanitize all the dissection tools with the sterilizing wipes. Cap the tube lined with the isoflurane soaked surgical pad. Replace the surgical pad on the foam board with a fresh surgical pad. Dispose the portions of the mouse that were not collected per the facility&#39;s animal disposal policy.</li>
</ol>

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	<li>Fesinmeyer, M. D., Austin, M. A., Li, C. I., De Roos, A. J., Bowen, 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=Differences+in+Survival+by+Histologic+Type+of+Pancreatic+Cancer.">Differences in Survival by Histologic Type of Pancreatic Cancer.</a> Cancer Epidemiol Biomarkers Prev. 14 (7), 1766-1773 (2005).</li><li>Jackson-Grusby, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+cancer+in+mice.">Modeling cancer in mice.</a> Oncogene. 21 (35), 5504-5514 (2002).</li><li>Heid, I., 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=Early+requirement+of+Rac1+in+a+mouse+model+of+pancreatic+cancer.">Early requirement of Rac1 in a mouse model of pancreatic cancer.</a> Gastroenterology. 141 (2), 719-730 (2011).</li><li>Hingorani, S. R., 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=Preinvasive+and+invasive+ductal+pancreatic+cancer+and+its+early+detection+in+the+mouse.">Preinvasive and invasive ductal pancreatic cancer and its early detection in the mouse.</a> Cancer cell. 4 (6), 437-450 (2003).</li><li>Shi, 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=KRAS2+Mutations+in+Human+Pancreatic+Acinar-Ductal+Metaplastic+Lesions+Are+Limited+to+Those+with+PanIN+Implications+for+the+Human+Pancreatic+Cancer+Cell+of+Origin.">KRAS2 Mutations in Human Pancreatic Acinar-Ductal Metaplastic Lesions Are Limited to Those with PanIN Implications for the Human Pancreatic Cancer Cell of Origin.</a> Mol Cancer Res. 7 (2), 230-236 (2009).</li><li>LaConti, J. J., 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=Distinct+serum+metabolomics+profiles+associated+with+malignant+progression+in+the+KrasG12D+mouse+model+of+pancreatic+ductal+adenocarcinoma.">Distinct serum metabolomics profiles associated with malignant progression in the KrasG12D mouse model of pancreatic ductal adenocarcinoma.</a> BMC Genomics. 16 (1), 1-10 (2015).</li><li>Ludwig, M. R., 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=Surveying+the+serologic+proteome+in+a+tissue-specific+kras(G12D)+knockin+mouse+model+of+pancreatic+cancer.">Surveying the serologic proteome in a tissue-specific kras(G12D) knockin mouse model of pancreatic cancer.</a> Proteomics. 16 (3), 516-531 (2016).</li><li>Taylor, D. K., Mook, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isoflurane+Waste+Anesthetic+Gas+Concentrations+Associated+with+the+Open-Drop+Method.">Isoflurane Waste Anesthetic Gas Concentrations Associated with the Open-Drop Method.</a> J Am Assoc Lab Anim Sci. 48 (1), 61-64 (2009).</li><li>Parasuraman, S., Raveendran, R., Kesavan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+sample+collection+in+small+laboratory+animals.">Blood sample collection in small laboratory animals.</a> J Pharmacol Pharmacother. 1 (2), 87-93 (2010).</li><li>Li, D. S., Yuan, Y. H., Tu, H. J., Liang, Q. L., Dai, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+protocol+for+islet+isolation+from+mouse+pancreas.">A protocol for islet isolation from mouse pancreas.</a> Nature Protocols. 4 (11), 1649-1652 (2009).</li><li>Auer, 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=The+effects+of+frozen+tissue+storage+conditions+on+the+integrity+of+RNA+and+protein.">The effects of frozen tissue storage conditions on the integrity of RNA and protein.</a> Biotech Histochem. 89 (7), 518-528 (2014).</li><li>Ma, J., Leung, L. 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The authors have nothing to disclose.

Significance with Respect to Existing Methods 
While other informal videos of mouse dissections exist, this video article provides the first professional quality, peer reviewed, visual demonstration of all of the detailed steps required for extraction and harvesting of the mouse pancreas by dissection10. With the pancreas being a main organ for metabolic activity and insulin production, dissection and harvesting of the pancreas allows for the preservation of the physiological...

The mouse has emerged as an important animal model of human pancreatic cancer1,2. In the Ptf1acre/+;LSL-KrasG12D/+ mouse model, the Kristen rat sarcoma (K-Ras) oncogene is activated exclusively in the pancreas, resulting in initiation of precancerous lesions in the pancreas, known as pancreatic intraepithelial neoplasias (PanINs), that progress to pancreatic ductal adenocarcinomas, commonly referred to as PDACs3. This mouse model system provides one of the best available animal models for human pancreatic cancer4,5, with the additional advantage that the PanINs emerge within the first five months of life and frequently progress to PDAC within a single year4,5, whereas pancreatic cancer most frequently occurs in humans 60-70 years of age.
Extraction of the pancreas by dissection from the Ptf1acre/+;LSL-KrasG12D/+ mice at various ages allows for detailed longitudinal histological examination of cancer development in the pancreas, ranging from the earliest PanIN stages through the progression to PDAC3,4,5. Harvesting the pancreas at ages ranging from five to fifteen months can also be used to prepare tissue extracts to characterize global changes in pancreas4 metabolism that occur during the transition from healthy to diseased tissue6,7.
This article presents a complete visual guide of the steps required to perform a mouse pancreas extraction and provides guidelines for storage of a pancreas for further analysis. This guide will be equally valuable for individuals conducting research on other pancreatic diseases, including type I diabetes, and should be especially useful to students and investigators new to research involving harvesting of the mouse pancreas using dissection for metabolic profiling or histological analyses.

<table><tbody><tr><td>Glass Jar&amp;nbsp;</td><td>Corning</td><td>3140-150</td><td>The glass jar used in the video has been discontinued.&amp;nbsp; This is its replacement.</td></tr><tr><td>Lid of Glass Jar</td><td>Corning</td><td>9985-150</td><td>The glass jar lid used in the video has been discontinued.&amp;nbsp; This is its replacement.</td></tr><tr><td>15 mL Falcon Tubes</td><td>Fisher Scientific</td><td>339650</td><td></td></tr><tr><td>Surgical Scissors</td><td>Fisher Scientific</td><td>9201</td><td></td></tr><tr><td>Squeeze bottle&amp;nbsp;</td><td>Fisher Scientific</td><td>03-409-10DD</td><td></td></tr><tr><td>100% Ethanol</td><td>Fisher Scientific</td><td>22-032-103</td><td></td></tr><tr><td>Formalin</td><td>Fisher Scientific</td><td>245-684</td><td></td></tr><tr><td>Foam Boards</td><td>Therapak</td><td>562908</td><td></td></tr><tr><td>Forceps</td><td>Fisher Scientific</td><td>200205SHN</td><td></td></tr><tr><td>1 mL 21G Syringes</td><td>BD Biosciences</td><td>309624</td><td></td></tr><tr><td>50 mL Falcon Tubes</td><td>Fisher Scientific</td><td>339652</td><td></td></tr><tr><td>2.0 mL Microcentrifuge Tubes&amp;nbsp;</td><td>Fisher Scientific</td><td>02-681-258</td><td></td></tr><tr><td>Surgical Pads</td><td>Fisher Scientific</td><td>S67011</td><td></td></tr><tr><td>T-Pins Length:&amp;nbsp; 2&quot;&amp;nbsp;</td><td>Advance Store Products</td><td>X32T-05</td><td></td></tr><tr><td>Sterilizing Wipes</td><td>Professional Disposables International Inc.</td><td>Q85084</td><td></td></tr><tr><td>Sharps Container</td><td>Fisher Scientific</td><td>14-827-122</td><td></td></tr><tr><td>Analytical Balance</td><td>Marshall Scientific</td><td>ME-AE200</td><td></td></tr><tr><td>4L Dewar</td><td>Taylor-Wharton</td><td>4LD</td><td></td></tr><tr><td>Shallow Wide Mouth Dewar</td><td>Fisher Scientific</td><td>F3087-V</td><td></td></tr><tr><td>Floating Microtube Rack</td><td>VWR</td><td>60986-100</td><td></td></tr><tr><td>Cryogenic Vial 1.2 mL, Sterile</td><td>Fisher Scientific</td><td>10-500-25</td><td></td></tr><tr><td>Isothesia (Isoflurane)&amp;nbsp;</td><td>Henry Schein Animal Health</td><td>050033</td><td></td></tr><tr><td>Liquid Nitrogen</td><td>Wright Brothers</td><td>NIT-60-XX</td><td></td></tr><tr><td>Mouse Kras Strain</td><td>The Jackson Laboratory</td><td>OO8179</td><td></td></tr><tr><td>Mouse Cre Strain</td><td>MMRRC</td><td>OOO435-UNC</td><td></td></tr></tbody></table>

dissection of the mouse pancreas for histological analysis and metabolic profiling

We have been investigating the pancreas specific transcription factor, 1a cre-recombinase; lox-stop-lox- Kristen rat sarcoma, glycine to aspartic acid at the 12 codon (Ptf1acre/+;LSL-KrasG12D/+) mouse strain as a model of human pancreatic cancer. The goal of our current studies is to identify novel metabolic biomarkers of pancreatic cancer progression. We have performed metabolic profiling of urine, feces, blood, and pancreas tissue extracts, as well as histological analyses of the pancreas to stage the cancer progression. The mouse pancreas is not a well-defined solid organ like in humans, but rather is a diffusely distributed soft tissue that is not easily identified by individuals unfamiliar with mouse internal anatomy or by individuals that have little or no experience performing mouse organ dissections. The purpose of this article is to provide a detailed step-wise visual demonstration to guide novices in the removal of the mouse pancreas by dissection. This article should be especially valuable to students and investigators new to research that requires harvesting of the mouse pancreas by dissection for metabolic profiling or histological analyses.

Figure 1 shows an overview of the operating environment area and Figure 2 shows the post operation area. While this setting provides the minimal amount of equipment and staging, individuals may choose to alter this to best suit individual needs. The protocol should be optimized according to the specific needs of the experiment. This procedure is conducted in a manner that terminates the life of a mouse, requiring proper euthaniza...

Watch this Scientific Journal Video about Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling at JoVE.com

Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling

This video article provides a detailed demonstration of the procedures required to successfully remove the pancreas from a mouse by dissection for histological analysis and metabolic profiling.

We have been investigating the pancreas specific transcription factor, 1a cre-recombinase; lox-stop-lox- Kristen rat sarcoma, glycine to aspartic acid at ...

dissection-mouse-pancreas-for-histological-analysis-metabolic

Research

JoVE Journal

Medicine

36.5K Views.  Miami University. Dit video artikel vindt u een uitgebreide demonstratie van de procedures die nodig zijn om met succes de alvleesklier van een muis door dissectie voor histologisch analyse en metabole profilering.

Video: Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling

Mimicking and Manipulating Pancreatic Acinar-to-Ductal Metaplasia in 3-dimensional Cell Culture

The differentiation of acinar cells to ductal cells during pancreatitis and in the early development of pancreatic cancer is a key process that requires further study. To understand the mechanisms regulating acinar-to-ductal metaplasia (ADM), ex vivo 3D culture and differentiation of primary acinar cells to ductal cells offers many advantages over other systems. With the technique herein, modulation of protein expression is simple and quick, requiring only one day to isolate, stimulate or virally infect, and begin culturing primary acinar cells to investigate the ADM process. In contrast to using basement membrane matrix, the seeding of acinar cell clusters in collagen I extracellular matrix, allows acinar cells to retain their acinar identity before manipulation. This is vital when testing the contribution of various components to the induction of ADM. Not only are the effects of cytokines or other ectopically administered factors testable through this technique, but the contribution of common mutations, increased protein expression, or knockdown of protein expression is testable via viral infection of primary acinar cells, using adenoviral or lentiviral vectors. Moreover, cells can be re-isolated from collagen or basement membrane matrix at the endpoint and analyzed for protein expression.

Primary acinar cell isolation, protein expression or activity modulation, culture, and down-stream applications are abundantly useful in the ex vivo study of acinar-to-ductal metaplasia (ADM), an early event in the development of pancreatic cancer.

The differentiation of acinar cells to ductal cells during pancreatitis and in the early development of pancreatic cancer is a key process that requires ...

Cancer Research

Isolating and Analyzing Cells of the Pancreas Mesenchyme by Flow Cytometry

The pancreas is comprised of epithelial cells that are required for food digestion and blood glucose regulation. Cells of the pancreas microenvironment, including endothelial, neuronal, and mesenchymal cells were shown to regulate cell differentiation and proliferation in the embryonic pancreas. In the adult, the function and mass of insulin-producing cells were shown to depend on cells in their microenvironment, including pericyte, immune, endothelial, and neuronal cells. Lastly, changes in the pancreas microenvironment were shown to regulate pancreas tumorigenesis. However, the cues underlying these processes are not fully defined. Therefore, characterizing the different cell types that comprise the pancreas microenvironment and profiling their gene expression are crucial to delineate the tissue development and function under normal and diseased states. Here, we describe a method that allows for the isolation of mesenchymal cells from the pancreas of embryonic, neonatal, and adult mice. This method utilizes the enzymatic digestion of mouse pancreatic tissue and the subsequent fluorescence-activated cell sorting (FACS) or flow-cytometric analysis of labeled cells. Cells can be labeled by either immunostaining for surface markers or by the expression of fluorescent proteins. Cell isolation can facilitate the characterization of genes and proteins expressed in cells of the pancreas mesenchyme. This protocol was successful in isolating and culturing highly enriched mesenchymal cell populations from the embryonic, neonatal, and adult mouse pancreas.

Here, we describe a method for the isolation of cells in the pancreas microenvironment from embryonic, neonatal and adult mouse tissue, focusing on the isolation of mesenchymal cells. This method allows profiling of cell gene expression and protein secretion in order to elucidate the extrinsic signals that regulate pancreas development, function, and tumorigenesis.

The pancreas is comprised of epithelial cells that are required for food digestion and blood glucose regulation. Cells of the pancreas microenvironment, ...

Developmental Biology

Single-cell Transcriptomic Analyses of Mouse Pancreatic Endocrine Cells

Pancreatic endocrine cells, which are clustered in islets, regulate blood glucose stability and energy metabolism. The distinct cell types in islets, including insulin-secreting &#946; cells, are differentiated from common endocrine progenitors during the embryonic stage. Immature endocrine cells expand via cell proliferation and mature during a long postnatal developmental period. However, the mechanisms underlying these processes are not clearly defined. Single-cell RNA-sequencing is a promising approach for the characterization of distinct cell populations and tracing cell lineage differentiation pathways. Here, we describe a method for the single-cell RNA-sequencing of isolated pancreatic &#946; cells from embryonic, neonatal and postnatal pancreases.

We describe a method for the isolation of endocrine cells from embryonic, neonatal and postnatal pancreases followed by single-cell RNA sequencing. This method allows analyses of pancreatic endocrine lineage development, cell heterogeneity and transcriptomic dynamics.

Pancreatic endocrine cells, which are clustered in islets, regulate blood glucose stability and energy metabolism. The distinct cell types in islets, ...

Pancreatic Tissue Dissection to Isolate Viable Single Cells

The pancreas includes two major systems: the endocrine system, which produces and secretes hormones, and the exocrine system, which accounts for approximately 90% of the pancreas and includes cells that produce and secrete digestive enzymes. The digestive enzymes are produced in the pancreatic acinar cells, stored in vesicles called zymogens, and are then released into the duodenum via the pancreatic duct to initiate metabolic processes. The enzymes produced by the acinar cells can kill cells or degrade cell-free RNA. In addition, acinar cells are fragile, and common dissociation protocols result in a large number of dead cells and cell-free proteases and RNases. Therefore, one of the biggest challenges in pancreatic tissue digestion is recovering intact and viable cells, especially acinar cells. The protocol presented in this article shows a two-step method that we developed to meet this need. The protocol can be used to digest normal pancreata, pancreata that include pre-malignant lesions, or pancreatic tumors that include a large number of stromal and immune cells.

Pancreatic metaplastic cells are precursors of malignant cells that give rise to pancreatic tumors. However, isolating intact viable pancreatic cells is challenging. Here, we present an efficient method for pancreatic tissue dissociation. The cells can then be used for single-cell RNA sequencing (scRNA-seq) or for two- or three-dimensional co-culturing.

The pancreas includes two major systems: the endocrine system, which produces and secretes hormones, and the exocrine system, which accounts for ...

In situ Quantification of Pancreatic Beta-cell Mass in Mice

Tracing changes of specific cell populations in health and disease is an important goal of biomedical research. The process of monitoring pancreatic beta-cell proliferation and islet growth is particularly challenging. We have developed a method to capture the distribution of beta-cells in the intact pancreas of transgenic mice with fluorescence-tagged beta-cells with a macro written for ImageJ (rsb.info.nih.gov/ij/). Following pancreatic dissection and tissue clearing, the entire pancreas is captured as a virtual slice, after which the GFP-tagged beta-cells are examined. The analysis includes the quantification of total beta-cell area, islet number and size distribution with reference to specific parameters and locations for each islet and for small clusters of beta-cells. The entire distribution of islets can be plotted in three dimensions, and the information from the distribution on the size and shape of each islet allows a quantitative and qualitative comparison of changes in overall beta-cell area at a glance.

In situ Quantification of Pancreatic Beta-cell Mass in Mice

The following protocol outlines the process of pancreatic dissection for virtual slice imaging, and the subsequent quantification of all GFP-tagged beta-cells in the entire pancreas.

Tracing changes of specific cell populations in health and disease is an important goal of biomedical research. The process of monitoring pancreatic ...

Biology

Leprdb Mouse Model of Type 2 Diabetes: Pancreatic Islet Isolation and Live-cell 2-Photon Imaging Of Intact Islets

Type 2 diabetes is a chronic disease affecting 382 million people in 2013, and is expected to rise to 592 million by 2035 1. During the past 2 decades, the role of beta-cell dysfunction in type 2 diabetes has been clearly established 2. Research progress has required methods for the isolation of pancreatic islets. The protocol of the islet isolation presented here shares many common steps with protocols from other groups, with some modifications to improve the yield and quality of isolated islets from both the wild type and diabetic Leprdb (db/db) mice. A live-cell 2-photon imaging method is then presented that can be used to investigate the control of insulin secretion within islets.

Leprdb Mouse Model of Type 2 Diabetes: Pancreatic Islet Isolation and Live-cell 2-Photon Imaging Of Intact Islets

We present here a protocol for the isolation of islets from the mouse model of type 2 diabetes, Leprdb and details of a live-cell assay for measurement of insulin secretion from intact islets that utilizes 2 photon microscopy.

Type 2 diabetes is a chronic disease affecting 382 million people in 2013, and is expected to rise to 592 million by 2035 1. During the past 2 decades, ...

Isolation and Culture of Mouse Primary Pancreatic Acinar Cells

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one week. More than 20 x 106 acinar cells can be obtained from a single murine pancreas. This protocol offers the possibility to independently process as many as 10 pancreases in parallel. Because it preserves acinar architecture, this model is well suited for studying the physiology of the exocrine pancreas in vitro in contrast to cell lines established from pancreatic tumors, which display many genetic alterations resulting in partial or total loss of their acinar differentiation.

In this publication, we describe a rapid and convenient procedure for isolating and culturing primary pancreatic acinar cells from the murine pancreas. This method constitutes a valuable approach to study the physiology of fresh primary normal/untransformed exocrine pancreatic cells.

This protocol permits rapid isolation (in less than 1 hr) of murine pancreatic acini, making it possible to maintain them in culture for more than one ...

Observing Islet Function and Islet-Immune Cell Interactions in Live Pancreatic Tissue Slices

Live pancreatic tissue slices allow for the study of islet physiology and function in the context of an intact islet microenvironment. Slices are prepared from live human and mouse pancreatic tissue embedded in agarose and cut using a vibratome. This method allows for the tissue to maintain viability and function in addition to preserving underlying pathologies such as type 1 (T1D) and type 2 diabetes (T2D). The slice method enables new directions in the study of the pancreas through the maintenance of the complex structures and various intercellular interactions that comprise the endocrine and exocrine tissues of the pancreas. This protocol demonstrates how to perform staining and time-lapse microscopy of live endogenous immune cells within pancreatic slices along with assessments of islet physiology. Further, this approach can be refined to discern immune cell populations specific for islet cell antigens using major histocompatibility complex-multimer reagents.

This study presents the application of live pancreatic tissue slices to the study of islet physiology and islet-immune cell interactions.

Live pancreatic tissue slices allow for the study of islet physiology and function in the context of an intact islet microenvironment. Slices are prepared ...

Immunology and Infection

A Mouse Model for Chronic Pancreatitis via Bile Duct TNBS Infusion

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. Several rodent models have been developed to study CP, of which the bile duct 2,4,6 -trinitrobenzene sulfonic acid (TNBS) infusion model replicates the features of neuropathic pain seen in CP. However, bile duct drug infusion in mice is technically challenging. This protocol demonstrates the procedure of bile duct TNBS infusion for generation of a CP mouse model. TNBS was infused into the pancreas through the ampulla of Vater in the duodenum. This protocol optimized drug volume, surgical techniques, and drug handling during the procedure. TNBS-treated mice showed features of CP as reflected by bodyweight and pancreas weight reductions, changes in pain-associated behaviors, and abnormal pancreatic morphology. With these improvements, mortality associated with TNBS injection was minimal. This procedure is not only critical in generating pancreatic disease models but is also useful in local pancreatic drug delivery.

Chronic pancreatitis (CP) is a disease characterized by inflammation and fibrosis of the pancreas, often associated with intractable abdominal pain. This article focuses on refining the technique to generate a mouse model of CP via bile duct infusion with 2,4,6 -trinitrobenzene sulfonic acid (TNBS).

Chronic pancreatitis (CP) is a complex disease involving pancreatic inflammation and fibrosis, glandular atrophy, abdominal pain and other symptoms. ...

Acinar-to-Ductal Metaplasia Induction: A Method to Study Acinar Cell to Ductal Cell Differentiation in 3D Ex Vivo Culture

Source: Fleming Martinez, A. K. et. al. <a href="https://www.jove.com/v/59096/" target="_blank">Mimicking and Manipulating Pancreatic Acinar-to-Ductal Metaplasia in 3-dimensional Cell Culture</a>. J. Vis. Exp. (2019).
This video describes the technique of differentiating pancreatic acinar cells to ductal cells in ex vivo 3D culture. This helps to understand the mechanisms regulating the acinar-to-ductal metaplasia (ADM), a key process in the early development of pancreatic cancer.

Source: Fleming Martinez, A. K. et. al. Mimicking and Manipulating Pancreatic Acinar-to-Ductal Metaplasia in 3-dimensional Cell Culture. J. Vis. Exp. ...

Dissection of the Mouse Pancreas for Histological Analysis and Metabolic Profiling

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