The authors acknowledge all colleagues who made this work possible; Ann Demarr&#233;, Veerle Laurysens, Jan De Jonge and Erik Quartier for technical assistance. Financial support was from the VUB Research Council, the Institute for the Promotion of Innovation by Science and Technology in Flanders (IWT), the Beta Cell Biology Consortium (BCBC), the Fund for Scientific Research Flanders (FWO), Diabetes Onderzoek Nederland (DON) and Interuniversity Attraction Pole (IAP).

All manipulations follow the guidelines issued by the European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes (ETS 123 and and 2010/63/EU).
1. Preparation of Work Area
<ol>
	<li>Provide a dedicated preparation area, a surgical area and a recovery area.</li>
	<li>Conduct the entire surgical procedure in a laminar flow cabinet to minimize environmental contaminants.</li>
	<li>Assemble the supplies (as listed in Materials and Methods) needed on the preparation, surgical and recovery area, using proper aseptic technique.</li>
	<li>Ensure that surgical tools are autoclaved prior to surgery.</li>
	<li>Provide a recirculating water heating pad at a temperature of 38 &#176;C for temperature stabilization during surgery. Cover the heating pad with a sterile waterproof pad.</li>
	<li>Provide an operating microscope with a magnification of at least 6.3X.</li>
	<li>Use an instrument sterilizer, such as a hot bead sterilizer, to sterilize instruments in between surgical procedures.</li>
	<li>Prepare a recovery area consisting of a large cage, lined by flat paper bedding</li>
</ol>

2. Preparing the Animals for Surgery
<ol>
	<li>For PDL and sham surgery, use 8 week old male mice, housed in standard cages and maintained on a 12 hr&#160;light/12 hr&#160;dark cycle and fed a standard rodent diet ad libitum. 
	Note: Here, we use BALB/cJrJ mice but we have also successfully used other strains and various transgenic strains.</li>
	<li>Use Buprenophine as preemptive analgesia (0.05 &#8211; 0.1 mg/kg) 30 min prior to surgery.</li>
	<li>Anesthetize the mice by intraperitoneal injection of 100 mg/kg of ketamine and 5 - 10 mg/kg of xylazine.</li>
	<li>Assess proper anesthetization by observing gradual loss of voluntary movement and muscle relaxation. Test the loss of reflexes by toe pinching.</li>
	<li>Apply ophthalmic ointment to prevent dryness of the eyes while under anesthesia.</li>
</ol>
3. Surgical Site Preparation
<ol>
	<li>Disinfect thorax and abdomen with antiseptic chlorhexidine solution.</li>
	<li>Shave an area of 2.5 cm x 1.5 cm of the abdomen.</li>
	<li>Disinfect the shaven area using gauze soaked with chlorhexidine solution, then alcohol solution and a final application of chlorhexidine solution.</li>
	<li>Position the animal in the surgical area so that the prepared surgical site is upwards facing the surgeon.</li>
	<li>Drape the mouse using a waterproof surgical drape with an opening that leaves the disinfected abdominal region exposed while covering the rest of the body to create a sterile working field. Monitor the mouse prior to the procedure for depth of anesthesia.</li>
</ol>
4. Pancreatic Duct Ligation
<ol>
	<li>Laparotomy
	<ol>
		<li>Make an upper midline incision in the skin extending from the xiphoid process to the umbilicus using a sterile surgical blade. Separate the underlying linea alba and the peritoneum using sterile scissors in order to expose the upper abdominal quadrant.</li>
		<li>Prevent drying-out of the internal organs by regular sprinkling with sterile 0.9% sodium chloride.</li>
		<li>Using sterile tweezers or swab, retract the stomach superiorly, exposing the spleen and the splenic lobe (the tail region) of the pancreas.</li>
		<li>Gently retract the duodenum and part of the upper jejunum to the right upper abdominal quadrant to expose the head, neck and body region of the pancreas covered by the visceral peritoneum.</li>
	</ol>
	</li>
	<li>Ligation
	<ol>
		<li>Locate the anatomical position of the pancreatic main duct in the neck region of the pancreas.</li>
		<li>Incise the visceral peritoneum and the gastrocolic ligament, granting access to the retroperitoneum, exposing the body and tail region of the pancreas. In order to expose the neck region, perform a Kocher maneuver. Lift the duodenum and head of the pancreas off the retroperitoneum elevating them from the inferior vena cava and aorta below.</li>
		<li>Carefully place the spatula underneath the neck region. Ligate the pancreatic duct with 6-0 Prolene thread at the left side of the portal vein that separates the gastro-duodenal and splenic lobes.</li>
		<li>Perform a second ligation in close proximity to the first ligation to ensure that the lobes are adequately separated.</li>
		<li>Ligate very carefully in order not to damage the underlying blood vessels, namely the superior pancreaticoduodenal artery, the inferior pancreaticoduodenal artery and the pancreatic part of the splenic artery.</li>
		<li>Place the organs back into the abdominal cavity.</li>
		<li>Close the incision using 4-0 polyglycol filamentous thread in a continuous suture pattern for the muscle/peritoneal layer and in a discontinuous suture pattern for the skin.</li>
	</ol>
	</li>
</ol>
5. Sham Surgery
<ol>
	<li>Perform all steps as described in steps 1 through 4.1.4. While the pancreas is exposed, do not perform ligation of the pancreatic duct.</li>
	<li>At the end of step 4.1.4, place internal organs back into the abdominal cavity.</li>
	<li>Close the incision as described in 4.2.7.</li>
</ol>
6. Post-operational Care and Monitoring
<ol>
	<li>After the surgical procedure is complete, place the mouse in the recovery area. This consists of a cage placed on a heating pad and lined with flat paper bedding in order to maintain normal body temperature.</li>
	<li>Provide nutritional support to avoid post-operative hypoglycemia by moistened food placed on the cage bottom. For this purpose, use standard rodent diet pellets soaked in water until they soften.</li>
	<li>Provide fluid support by the moistened food and provide water ad libitum.</li>
	<li>Use Buprenophine as analgesia (0.05 &#8211; 0.1 mg/kg) twice daily for 2 days post-surgery. During the entire experimental, follow up, observe the mice for occurrence of possible signs of infection, including secretion of liquid or pus from the wound, or for physical deterioration characterized by reduction in grooming behavior and activity level, lower appetite and bodyweight loss.</li>
</ol>
7. Evaluation of Successful PDL and Harvest of PDL Tail and Sham Tail Pancreas
<ol>
	<li>Euthanize mice by cervical dislocation.</li>
	<li>Re-shave the abdominal region to avoid carry-over of fur.</li>
	<li>Open the abdominal skin and muscle layer and remove a large area of skin and muscle to obtain good access to the pancreas.</li>
	<li>Using sterile tweezers or swab, the stomach is retracted superiorly, exposing the spleen and the splenic lobe (the tail region) of the pancreas.</li>
	<li>Gently pull out the duodenum and part of the upper jejunum to expose the gastro-duodenal lobe (head region) of the pancreas. 
	Note: The ligated portion of the PDL pancreas has now reduced in size and has become almost translucent so that islets are visible as small white dots. The head portion of the pancreas is opaque pink and distinct exocrine lobuli can be observed.</li>
	<li>Using sterile scissors, separate the ligated tail part of the pancreas from the spleen, by cutting along the spleen. Cut loose the connective tissue connecting the tail region of the pancreas to the internal organs.</li>
	<li>Cut the PDL tail region right in front of the ligation, excluding the ligature and the tissue immediately adjacent to it from the harvested tissue.</li>
	<li>To isolate sham tail tissue, follow steps 7.1 through 7.5. Using sterile scissors separate the tail region of the sham pancreas from the spleen by cutting along the spleen. Isolate the tail region by cutting into the neck region of the pancreas and cutting loose the connective tissue connecting the tail pancreas to the internal organs 
	Note: Both the tail and head region of the sham pancreas are opaque pink, to isolate both parts separately, cut the pancreas in the neck region.</li>
</ol>

<ol>
	<li>Shaw, J. E., Sicree, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+estimates+of+the+prevalence+of+diabetes+for.">Global estimates of the prevalence of diabetes for.</a> Diabetes Res Clin Pract. 87, 4-14 (2010).</li><li>Danaei, 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=National,+regional,+and+global+trends+in+fasting+plasma+glucose+and+diabetes+prevalence+since+1980:+systematic+analysis+of+health+examination+surveys+and+epidemiological+studies+with+370+country-years+and+2&#183;7+million+participants.">National, regional, and global trends in fasting plasma glucose and diabetes prevalence since 1980: systematic analysis of health examination surveys and epidemiological studies with 370 country-years and 2&#183;7 million participants.</a> Lancet. 378, 31-40 (2011).</li><li>Borowiak, M., Melton, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+make+beta+cells.">How to make beta cells.</a> Current opinion in Cell Biology. 21, 727-732 (2009).</li><li>Gradwohl, G., Dierich, A., LeMeur, M., Guillemot, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=neurogenin3+is+required+for+the+development+of+the+four+endocrine+cell+lineages+of+the+pancreas.">neurogenin3 is required for the development of the four endocrine cell lineages of the pancreas.</a> Proc Natl Acad Sci U S A. 97, 1607-1611 (2000).</li><li>Gu, G., Dubauskaite, J., Melton, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+evidence+for+the+pancreatic+lineage:+NGN3++cells+are+islet+progenitors+and+are+distinct+from+duct+progenitors.">Direct evidence for the pancreatic lineage: NGN3+ cells are islet progenitors and are distinct from duct progenitors.</a> Development. 129, 2447-2457 (2002).</li><li>Dor, Y., Brown, J., Martinez, O. I., Melton, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult+pancreatic+beta-cells+are+formed+by+self-duplication+rather+than+stem-cell+differentiation.">Adult pancreatic beta-cells are formed by self-duplication rather than stem-cell differentiation.</a> Nature. 429, 41-46 (2004).</li><li>Teta, M., Rankin, M. M., Long, S. Y., Stein, G. M., Kushner, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+regeneration+of+adult+beta+cells+does+not+involve+specialized+progenitors.">Growth and regeneration of adult beta cells does not involve specialized progenitors.</a> Dev Cell. 12, 817-826 (2007).</li><li>Bonner-Weir, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Perspective:+Postnatal+pancreatic+beta+cell+growth.">Perspective: Postnatal pancreatic beta cell growth.</a> Endocrinology. 141, 1926-1929 (2000).</li><li>Brennand, K., Huangfu, D., Melton, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=All+beta+cells+contribute+equally+to+islet+growth+and+maintenance.">All beta cells contribute equally to islet growth and maintenance.</a> PLoS Biol. 5, e163 (2007).</li><li>Salpeter, S. J., Klein, A. M., Huangfu, D., Grimsby, J., Dor, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glucose+and+aging+control+the+quiescence+period+that+follows+pancreatic+beta+cell+replication.">Glucose and aging control the quiescence period that follows pancreatic beta cell replication.</a> Development. 137, 3205-3213 (2010).</li><li>Xu, X., 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=Beta+cells+can+be+generated+from+endogenous+progenitors+in+injured+adult+mouse+pancreas.">Beta cells can be generated from endogenous progenitors in injured adult mouse pancreas.</a> Cell. 132, 197-207 (2008).</li><li>Wang, R. N., Kloppel, G., Bouwens, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Duct-+to+islet-cell+differentiation+and+islet+growth+in+the+pancreas+of+duct-ligated+adult+rats.">Duct- to islet-cell differentiation and islet growth in the pancreas of duct-ligated adult rats.</a> Diabetologia. 38, 1405-1411 (1995).</li><li>Yasuda, 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=Cytokine+expression+and+induction+of+acinar+cell+apoptosis+after+pancreatic+duct+ligation+in+mice.">Cytokine expression and induction of acinar cell apoptosis after pancreatic duct ligation in mice.</a> Journal of interferon, &amp; cytokine research : the official journal of the International Society for Interferon and Cytokine Research. 19, 637-644 (1999).</li><li>Van Gassen, 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=Macrophage+dynamics+are+regulated+by+local+macrophage+proliferation+and+monocyte+recruitment+in+injured+pancreas.">Macrophage dynamics are regulated by local macrophage proliferation and monocyte recruitment in injured pancreas.</a> European journal of immunology. , (2015).</li><li>Van de Casteele, 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=Neurogenin+3++cells+contribute+to+beta-cell+neogenesis+and+proliferation+in+injured+adult+mouse+pancreas.">Neurogenin 3+ cells contribute to beta-cell neogenesis and proliferation in injured adult mouse pancreas.</a> Cell Death Dis. 4, e523 (2013).</li><li>Xiao, X., 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=No+evidence+for+beta+cell+neogenesis+in+murine+adult+pancreas.">No evidence for beta cell neogenesis in murine adult pancreas.</a> The Journal of clinical investigation. 123, 2207-2217 (2013).</li><li>Ackermann Misfeldt, A., Costa, R. H., Gannon, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta-cell+proliferation,+but+not+neogenesis,+following+60%+partial+pancreatectomy+is+impaired+in+the+absence+of+FoxM1.">Beta-cell proliferation, but not neogenesis, following 60% partial pancreatectomy is impaired in the absence of FoxM1.</a> Diabetes. 57, 3069-3077 (2008).</li><li>Lee, C. S., De Leon, D. D., Kaestner, K. H., Stoffers, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regeneration+of+pancreatic+islets+after+partial+pancreatectomy+in+mice+does+not+involve+the+reactivation+of+neurogenin-3.">Regeneration of pancreatic islets after partial pancreatectomy in mice does not involve the reactivation of neurogenin-3.</a> Diabetes. 55, 269-272 (2006).</li><li>Bonner-Weir, S., Sharma, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pancreatic+stem+cells.">Pancreatic stem cells.</a> The Journal of pathology. 197, 519-526 (2002).</li><li>Nir, T., Melton, D. A., Dor, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recovery+from+diabetes+in+mice+by+beta+cell+regeneration.">Recovery from diabetes in mice by beta cell regeneration.</a> The Journal of clinical investigation. 117, 2553-2561 (2007).</li><li>Bouwens, L., Rooman, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+pancreatic+beta-cell+mass.">Regulation of pancreatic beta-cell mass.</a> Physiol Rev. 85, 1255-1270 (2005).</li><li>Wang, 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=Neurog3+gene+dosage+regulates+allocation+of+endocrine+and+exocrine+cell+fates+in+the+developing+mouse+pancreas.">Neurog3 gene dosage regulates allocation of endocrine and exocrine cell fates in the developing mouse pancreas.</a> Developmental biology. 339, 26-37 (2010).</li><li>Pan, F. 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=Spatiotemporal+patterns+of+multipotentiality+in+Ptf1a-expressing+cells+during+pancreas+organogenesis+and+injury-induced+facultative+restoration.">Spatiotemporal patterns of multipotentiality in Ptf1a-expressing cells during pancreas organogenesis and injury-induced facultative restoration.</a> Development. 140, 751-764 (2013).</li><li>Kopp, J. L., 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=Sox9++ductal+cells+are+multipotent+progenitors+throughout+development+but+do+not+produce+new+endocrine+cells+in+the+normal+or+injured+adult+pancreas.">Sox9+ ductal cells are multipotent progenitors throughout development but do not produce new endocrine cells in the normal or injured adult pancreas.</a> Development. 138, 653-665 (2011).</li><li>Wang, 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=Sustained+Neurog3+expression+in+hormone-expressing+islet+cells+is+required+for+endocrine+maturation+and+function.">Sustained Neurog3 expression in hormone-expressing islet cells is required for endocrine maturation and function.</a> Proc Natl Acad Sci U S A. 106, 9715-9720 (2009).</li><li>Kopinke, 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=Lineage+tracing+reveals+the+dynamic+contribution+of+Hes1++cells+to+the+developing+and+adult+pancreas.">Lineage tracing reveals the dynamic contribution of Hes1+ cells to the developing and adult pancreas.</a> Development. 138, 431-441 (2011).</li><li>Rankin, M. 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=beta-Cells+are+not+generated+in+pancreatic+duct+ligation-induced+injury+in+adult+mice.">beta-Cells are not generated in pancreatic duct ligation-induced injury in adult mice.</a> Diabetes. 62, 1634-1645 (2013).</li><li>Solar, 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=Pancreatic+exocrine+duct+cells+give+rise+to+insulin-producing+beta+cells+during+embryogenesis+but+not+after+birth.">Pancreatic exocrine duct cells give rise to insulin-producing beta cells during embryogenesis but not after birth.</a> Dev Cell. 17, 849-860 (2009).</li><li>Furuyama, K., 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=Continuous+cell+supply+from+a+Sox9-expressing+progenitor+zone+in+adult+liver,+exocrine+pancreas+and+intestine.">Continuous cell supply from a Sox9-expressing progenitor zone in adult liver, exocrine pancreas and intestine.</a> Nat Genet. 43, 34-41 (2011).</li><li>Van de Casteele, 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=Partial+duct+ligation:+beta-cell+proliferation+and+beyond.">Partial duct ligation: beta-cell proliferation and beyond.</a> Diabetes. 63, 2567-2577 (2014).</li><li>Zhang, J., Rouse, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histopathology+and+pathogenesis+of+caerulein-,+duct+ligation-,+and+arginine-induced+acute+pancreatitis+in+Sprague-Dawley+rats+and+C57BL6+mice.">Histopathology and pathogenesis of caerulein-, duct ligation-, and arginine-induced acute pancreatitis in Sprague-Dawley rats and C57BL6 mice.</a> Histology and histopathology. 29, 1135-1152 (2014).</li><li>Martinez-Romero, 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=The+epigenetic+regulators+Bmi1+and+Ring1B+are+differentially+regulated+in+pancreatitis+and+pancreatic+ductal+adenocarcinoma.">The epigenetic regulators Bmi1 and Ring1B are differentially regulated in pancreatitis and pancreatic ductal adenocarcinoma.</a> The Journal of pathology. 219, 205-213 (2009).</li><li>Prevot, P. 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=Role+of+the+ductal+transcription+factors+HNF6+and+Sox9+in+pancreatic+acinar-to-ductal+metaplasia.">Role of the ductal transcription factors HNF6 and Sox9 in pancreatic acinar-to-ductal metaplasia.</a> Gut. 61, 1723-1732 (2012).</li></ol>

The authors have nothing to disclose.

In the present study, we describe in detail the methodology behind PDL, a mouse injury model to study beta cell neogenesis and proliferation and transdifferentiation of pancreatic non-beta cells. Ambiguity in data on PDL among labs stimulates the need for a standardized protocol for PDL surgery.
Critical steps in the PDL protocol include the selection of healthy, young mice for surgery. Preferably male mice should be used since unpublished data from our lab suggest that estrogen receptor signa...

The increasing prevalence of diabetes, affecting more than 300 million people world-wide1,2 has boosted the search for new sources of insulin-producing beta cells, both in vitro and in vivo, to replenish the deficient beta cell mass.3 Identifying key mechanisms and factors that regulate beta cell proliferation and beta cell neogenesis, i.e., the differentiation of beta cells from a non-beta cell or progenitor cell, can provide novel targets for the development of regenerative therapies in diabetes.
In the developing rodent pancreas, all of the endocrine cell types differentiate from a transient population of endocrine progenitor cells, expressing the transcription factor Neurogenin3 (Ngn3).4,5 In the adult rodent pancreas, under normal physiological conditions, the beta cell mass is maintained at an optimal number to meet metabolic demands. Changes in beta cell size, apoptosis and replication constitute the major mechanisms for beta cell expansion and turn-over.6-8 While the potential of beta cells to proliferate under normal physiological conditions is homogenous throughout the population,9 their proliferation rate is low and re-replication is restricted by a dynamic quiescence period or refractory period6,7, influenced by age and glucose metabolism.10 Since endocrine progenitor cells have so far not been identified in the normal adult pancreas, neogenesis is thought to not contribute to normal adult beta cell growth.8
Therefore, the identification of a facultative endocrine progenitor cell in the adult pancreas that is expandable and capable of yielding new beta cells would provide a novel, possibly unlimited source of beta cells.
Partial duct ligation (PDL) is an animal injury model that has been described to induce beta cell neogenesis in the adult pancreas.11,12 In this model, the main pancreatic duct draining the pancreatic tail is surgically ligated. The resulting obstruction of exocrine drainage induces major tissue remodeling, accompanied by inflammation and acinar atrophy distal to the ligation.12-14 Within this inflammatory environment, re-expression of the endocrine progenitor marker Ngn3 is induced and the beta cell volume increases two-fold. This doubling in beta cell volume results from the generation of new beta cells from an Ngn3 expressing embryonic-type endocrine progenitor cell and from proliferation of pre-existing and newly-formed beta cells that are prone to re-duplication without &#8220;quiescence period&#8221;.11,15
Beta cell neogenesis and replication in injury models, such as pancreatectomy6,7,16-19 and selective ablation of beta cells20 have been extensively described. However, the regenerative outcome in these models is influenced by the extent of the inflicted damage and is associated with a decreased initial beta cell mass21. PDL is a surgical model in which the initial beta cell mass is not affected and beta cell neogenesis and proliferation are robustly activated. Indeed, in the pancreas of mice that underwent PDL, Ngn3 expressing cells are identified near the epithelial lining of the duct. These cells can be isolated from the ligated pancreas of Ngn3-GFP transgenic mice using fluorescence activated cell sorting (FACS) and are able to differentiate towards functional beta cells following engraftment into and ex vivo culture of the pancreas of E12.5 Ngn3-/- mice.11 Similarly, in Ngn3CreERT;R26YFP mice in which cells that activated the Ngn3 gene are permanently labeled after tamoxifen injection, label-positive Ngn3 cell-derived beta cells are detected after PDL.15 Moreover, newly formed beta cells dilute pre-existing beta cells and preferentially locate in small islets within which beta cells show high proliferation potential.15 Ngn3 is important for beta cell expansion after PDL since decreased Ngn3 expression using target-specific short-hairpin RNA significantly decreases beta cell mass and beta cell proliferation after PDL.11 Notably, the fraction of Ngn3 cell-derived beta cells and the beta cell mass after PDL critically depends on the level of Ngn3 induction15. This is in accordance with the observation that high level of&#160;Ngn3&#160;expression is a critical step for endocrine commitment from multipotent pancreatic progenitors during pancreatic development.22 In addition, selective ablation of Ngn3 expressing cells by diphtheria-toxin administration to Ngn3CreERT;R26iDTR mice results in decreased insulin content and reduced beta cell proliferation, especially in small islets.15
Although the induction of Ngn3 expression in duct cells after PDL has been confirmed by many11,15,16,23,24, Ngn3 expression in islets cells24,25 and discrepancies in outcome of PDL challenged our initial observations of increased beta cell mass26,27, appearance of Ngn3 expressing duct-derived endocrine progenitors24,26,28,29 , and increased beta cell proliferation27 after PDL.30
These conflicting results could, at least partially, be attributed to a combination of factors, including variations in the post-surgical time points of analysis, bodyweight, sex and age of the mice, post-operative physiological and environmental conditions and, most importantly, differences in surgical technique.30 In our hands, beta cell proliferation, insulin content, beta cell volume and the number of small islets are consistently increased after PDL. Also Ngn3 mRNA consistently increases, but there are large differences in the Ngn3 mRNA expression between PDL tail pancreases, for which we have no direct explanation. We hypothesized that the level of Ngn3 mRNA might correlate with the degree of beta cell neogenesis from non-beta cells15, but this needs further substantiation. Although it does not remove all experimental variations, a standardized method for performing PDL surgery allows for better uniformity in results and opens new avenues in studying beta cell proliferation and neogenesis.

<table border="0" cellpadding="0" cellspacing="0">
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		<tr>
			<td>Supplies for preparation area&#160;</td>
			<td></td>
			<td></td>
			<td></td>
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		<tr>
			<td>Hibiscrub&#160;</td>
			<td>Regent Medical</td>
			<td>5601IE5F11</td>
			<td>Chlorhexidin diglucon</td>
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		<tr>
			<td>Ketamin</td>
			<td>Ceva</td>
			<td>BE-V202526</td>
			<td>anesthesia</td>
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			<td>Rompun(2%) (Xylazin)</td>
			<td>Bayer</td>
			<td>BE-V041815</td>
			<td>anesthesia</td>
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		<tr>
			<td>Duratears</td>
			<td>Alcon</td>
			<td>34335-8</td>
			<td>ointment for eyes</td>
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			<td>Razor</td>
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			<td></td>
			<td></td>
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		<tr>
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			<td>Supplies for surgical area&#160;</td>
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			<td>Leica Operating microscope</td>
			<td>Leica</td>
			<td>10446320</td>
			<td></td>
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		<tr>
			<td>Hot bead sterilizer</td>
			<td>Fine Science Tools (FST)</td>
			<td>18000-45</td>
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		<tr>
			<td>autoclaved surgical instruments</td>
			<td>Fine Science Tools (FST)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Recirclulating water heating pad</td>
			<td>Gaymar Industries, Inc.</td>
			<td>TP702</td>
			<td></td>
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			<td>Adhesive OP-towel</td>
			<td>BARRIER</td>
			<td>706500-07</td>
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			<td>OP-tape</td>
			<td>BARRIER</td>
			<td>381035-00</td>
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			<td>Stella 3/5 Compresse de gaze (Sterile)</td>
			<td>Lohmann&#38;Rauscher International</td>
			<td>35968</td>
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			<td>Mini Plasco 0,9% NaCl solution</td>
			<td>B.BRAUN</td>
			<td>3521680</td>
			<td></td>
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			<td>6-0 prolene suture</td>
			<td>Ethicon</td>
			<td>8706H</td>
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			<td>4-0 polyglycol suture</td>
			<td>Ethicon</td>
			<td>SL-607</td>
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			<td></td>
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			<td></td>
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			<td>Supplies for recovery area</td>
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			<td></td>
			<td></td>
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			<td>Paper bedding (paper towel)</td>
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			<td>Vetergesic</td>
			<td>ecuPhar</td>
			<td>BE-V342955</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Materials for analysis</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Taqman Ngn3 primer</td>
			<td>Integrated DNA technologies</td>
			<td>Mm.PT.56a.33574796.gs</td>
			<td></td>
		</tr>
		<tr>
			<td>Taqman CycloA primer</td>
			<td>Integrated DNA technologies</td>
			<td>Mm.PT.39a.2.gs</td>
			<td></td>
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		<tr>
			<td>anti-Rabbit Cleaved Caspase 3 antibody (D175)</td>
			<td>Cell Signaling</td>
			<td>5A1E</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-mouse/rat Ki67 antibody</td>
			<td>eBioscience</td>
			<td>14-5698-82</td>
			<td></td>
		</tr>
		<tr>
			<td>monoclonal anti-actin alpha-Smooth muscle-Cy3 (mouse)</td>
			<td>Sigma</td>
			<td>085K4889</td>
			<td></td>
		</tr>
		<tr>
			<td>anti-rat Cytokeratin 19&#160;</td>
			<td>DSHB</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>monoclonal Mouse anti-BrdU</td>
			<td>Dako</td>
			<td>M0744</td>
			<td></td>
		</tr>
		<tr>
			<td>Hoechst</td>
			<td>Sigma</td>
			<td>33342</td>
			<td></td>
		</tr>
	</tbody>
</table>

surgical injury to the mouse pancreas through ligation of the pancreatic duct as a model for endocrine and exocrine reprogramming and proliferation

胚または成体幹細胞からの分化によってin vivoまたはex vivoで 、またはβ細胞の発生における膵臓β細胞の拡大は、糖尿病の治療法として、ヒト膵島 ​​移植におけるドナーの不足を緩和するβ細胞の新しい拡張可能な供給源を提供することができます。最近の進歩は、この目標に向けてなされてきたが、幹細胞/前駆細胞からβ細胞の増殖および分化を制御する機構を特徴づけされていません。ここでは、組織リモデリングおよびβ細胞の増殖および分化のメカニズムを研究するためのツールと​​して機能することができる成体マウスの膵臓における傷害モデルのためのプロトコルを説明します。部分管結紮（PDL）は、膵臓の尾部領域のうち外分泌物の排水の閉塞をもたらす主膵管の外科的結紮を伴うげっ歯類膵臓の実験的に誘導損傷です。被害は腺房萎縮、免疫細胞infiltを誘導します配給、重度組織再構築。我々は以前、内因性前駆細胞様細胞およびPDL後のβ細胞増殖の増加を表現するニューロゲニン（NGN）3の活性化を報告しています。したがって、PDLは、ベータ細胞の動態に関与するシグナルと成人膵臓内分泌前駆細胞の性質を研究するための基礎を提供します。 、それはまだ要因と経路がPDLにおけるβ細胞新生および増殖に寄与する、大部分は不明のままであるので、PDLのための標準化されたプロトコルは、研究室全体の比較を可能にします。

PDL induces acinar atrophy and inflammation but does not affect bodyweight and glycemia
In 8 week old male BALB/c mice, the duct draining the exocrine enzymes from the tail of the pancreas is ligated while the organ&#8217;s head, located adjacent to the stomach and duodenum, remains unaffected. Age, sex and weight-matched male BALB/c mice undergo sham surgery recapitulating all steps of partial duct ligation surgery, except the ligation of the pancreatic duct. Pancreas tissue ...

Watch this Scientific Journal Video about Surgical Injury to the Mouse Pancreas through Ligation of the Pancreatic Duct as a Model for Endocrine and Exocrine Reprogramming and Proliferation at JoVE.co

Surgical Injury to the Mouse Pancreas through Ligation of the Pancreatic Duct as a Model for Endocrine and Exocrine Reprogramming and Proliferation

This protocol describes an injury model involving the surgical ligation of the pancreatic duct in the adult mouse pancreas, resulting in severe injury that establishes an environment that allows beta cell neogenesis and proliferation. This model can be used as a tool to study mechanisms involved in beta cell formation.

内分泌と外分泌リプログラミングおよび増殖のためのモデルとしての膵管の連結を介して、マウスの膵臓への外科的損傷

Expansion of pancreatic beta cells in vivo or ex vivo, or generation of beta cells by differentiation from an embryonic or adult stem cell, can provide ...

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16.0K ビュー.  Vrije Universiteit Brussel. This protocol describes an injury model involving the surgical ligation of the pancreatic duct in the adult mouse pancreas, resulting in severe injury that establishes an environment that allows beta cell neogenesis and proliferation. This model can be used as a tool to study mechanisms involved in beta cell formation. 

ビデオ: Surgical Injury to the Mouse Pancreas through Ligation of the Pancreatic Duct as a Model for Endocrine and Exocrine Reprogramming and Proliferation