We thank Jolanta Chmielowiec for helpful discussion regarding the protocol and manuscript. We also thank Benjamin Arenkiel for access to confocal microscope. This work was supported by the NIH (P30-DK079638 to M.B. and T32HL092332-13 to M.A.S. and M.B.), the McNair Medical Foundation (to M.B.), and the confocal core at the BCM Intellectual and Developmental Disabilities Research Center (NIH U54 HD083092 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development).

All animal experiments described in this method were approved by the Institutional Animal Care and Use Committee of Baylor College of Medicine.
1. Preparation of Mouse Embryonic Day 10.5 Pancreatic Progenitors
Note: This protocol does not need to be followed under sterile conditions until step 2, however it is optimal to sterilize dissection tools and spray with 70% ethanol prior to use.
<ol>
	<li>To set up for dissection, fill an ice bucket and place a container ...

<ol>
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The progression of cell culture models is critical to properly model development, produce clinically relevant cell types, test drug efficacy, or even transplant to patients. However, artificially recapitulating development in a dish is challenging as we are still far from understanding the mechanisms of organogenesis and physiology in vivo. Thus in vitro cells are inefficiently generated, not fully functional, unable to be maintained for long periods of time, or harbor other abnormalities from comparabl...

Delineating the mechanisms of the normal development and the physiology is paramount to understand disease etiology and ultimately cultivate treatment methods. While culturing and differentiating stem cells enables quick and high-throughput analysis of development, it is limited by the existing body of knowledge regarding mechanisms regulating cell fate and artificially recapitulates development in a relatively homogenous, two-dimensional state1,2. Not only is in vivo development affected by extrinsic influences, with different cell types in the niche and milieu providing paracrine signals and organizational support to guide organogenesis, but the function of these cells also relies on their surroundings for guidance3,4,5. Given the importance of these external cues, the limitations of differentiation protocols, and the laborious nature of in vivo mouse models, new systems are needed to experimentally investigate basic developmental processes and physiology.
The emergence of protocols to generate three-dimensional, complex organoids provides a convenient and congruent system to study organogenesis, physiology, drug efficacy, and even pathogenesis. Establishing murine organoids for different systems such as the stomach6 and intestine7 have expanded our understanding of organogenesis, providing a tool to study developmental complexities with fewer restrictions than in vivo and in vitro models. Due to these advances in the murine organoid formation and the advent of human pluripotent stem cells, human intestinal8, retinal9, renal10,11, and cerebral12 organoids have been produced, and this repertoire is only limited by the existing knowledge regarding mechanisms of development.
Of particular interest is the generation of pancreatic organoids, as a myriad of diseases plagues different pancreatic cell types, including acinar cells and ducts in exocrine pancreatic insufficiency13, acinar cells in pancreatitis14, and beta cells in diabetes15. Gaining knowledge regarding the development of these different cell types could aid in understanding their pathology and can, also, act as a platform for personalized drug screening or transplantation. Previously, Greggio et al. developed a method to create murine pancreatic organoids that recapitulate in vivo morphogenesis and develop organized, three-dimensional, complex structures composed of all major pancreatic epithelial cell types16,17. This is a major step forward in the pancreatic field, especially as making cells in vitro can enable biological investigation of beta-cell development. However, a scarcity of endocrine cells formed in this protocol unless the organoids were transplanted into tissue, where the niche could interact and provide instructional cues17. The mesenchyme constitutes the largest portion of the niche, heavily enveloping the developing epithelium from early stages of organogenesis to later stages including endocrine delamination and differentiation3,4,18. The interaction of the mesenchyme with the developing pancreas is yet another example of extrinsic signaling and the importance of maintaining in vivo cellular complexity to study organogenesis.
Here, we describe how to generate three-dimensional pancreatic organoids, termed pancreatoids, from dissociated e10.5 murine pancreatic progenitors. These pancreatoids retain native mesenchyme, self-assemble in free-floating conditions, and generate all major pancreatic cell types, including a robust number of endocrine beta cells19. This approach is best suited for the analysis of endocrine development, as previous protocols lack robust endocrine differentiation. However, using the protocol for pancreatic organoids as described by Greggio et al. is better suited for analysis of pancreatic epithelial branching and morphogenesis, as branching is more limited in pancreatoids.

<table border="0" cellpadding="0" cellspacing="0" style="width:849px;" width="849">
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		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">2-Mercaptoethanol</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">M6250</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Aspirator Tube Assemblies for Calibrated Microcapillary Pipettes</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">A5177</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">BarnStead NanoPure Nuclease-free water</td>
			<td>ThermoFisher</td>
			<td>D119</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Borosilicate Capillary Tubes</td>
			<td style="width:123px;">Sutter Instruments</td>
			<td style="width:344px;">GB1007515</td>
			<td style="width:167px;">O.D. 1mm, I.D. 0.75mm, 1.5cm length</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">CaCl2</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">C5080</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Cell-Repellent 96-Well Microplate</td>
			<td style="width:123px;">Greiner Bio-One</td>
			<td style="width:344px;">650970</td>
			<td style="width:167px;">U-bottom</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Centrifuge 5424 R</td>
			<td>Eppendorf</td>
			<td>5401000013</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Chloroform</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">233306</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Chromogranin-A antibody</td>
			<td>Abcam</td>
			<td>ab15160</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Compact, Modular Stereo Microscope M60</td>
			<td style="width:123px;">Leica</td>
			<td style="width:344px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Countess Automated Cell Counter</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">C10310</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Countess Cell Counter Slides</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">C10312</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">CryoStar NX70</td>
			<td>ThermoFisher</td>
			<td>957000L</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">D-(+)-Glucose</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">G7528</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">DAPI (4&#39;,6-Diamidine-2&#39;-phenylindole-dihydrochloride)</td>
			<td style="width:123px;">Roche</td>
			<td style="width:344px;">10 236 276 001</td>
			<td style="width:167px;">Powder</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">DBA antibody</td>
			<td>Vector Lab</td>
			<td>RL-1032</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Dispase II, Powder</td>
			<td style="width:123px;">Gibco</td>
			<td style="width:344px;">17105041</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">DMEM/F-12, HEPES</td>
			<td style="width:123px;">Gibco</td>
			<td style="width:344px;">11330032</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Dnase I</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">18068-015</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Dumont #5 Forceps</td>
			<td style="width:123px;">Fine Science Tools</td>
			<td style="width:344px;">11251-10</td>
			<td style="width:167px;">0.05 x 0.02 mm; Titanium; Biology tip</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">EGF (Epidermal growth factor)</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">E9644</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Ethanol, 200 Proof</td>
			<td style="width:123px;">Decon Laboratories</td>
			<td style="width:344px;">2716</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Forma Steri Cycle CO2 Incubators</td>
			<td style="width:123px;">ThermoFisher</td>
			<td style="width:344px;">370</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Fluoromount-G</td>
			<td style="width:123px;">Southern Biotech</td>
			<td style="width:344px;">OB10001</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Heparin sodium salt from porcine intestinal mucosa</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">H3149-10KU</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">INSM1 Antibody</td>
			<td style="width:123px;">Santa Cruz BioTechnology</td>
			<td style="width:344px;">sc-271408</td>
			<td style="width:167px;">Polyclonal Mouse IgG</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Isopropanol</td>
			<td style="width:123px;">Fisher</td>
			<td style="width:344px;">a4164</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Isothesia Isoflurane, USP</td>
			<td>Henry Schein</td>
			<td>11695-6776-2</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Insulin Antibody</td>
			<td style="width:123px;">Dako</td>
			<td style="width:344px;">A056401</td>
			<td style="width:167px;">Polyclonal Guinea Pig</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">KAPA SYBR FAST Universal</td>
			<td style="width:123px;">KAPA Biosystems</td>
			<td style="width:344px;">KK4618</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">KCl</td>
			<td style="width:123px;">KaryoMax</td>
			<td>10575090</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">KnockOut Serum Replacement</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">10828028</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Leica TCS SPE High-Resolution Spectral Confocal</td>
			<td style="width:123px;">Leica</td>
			<td style="width:344px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">MgCl2</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">442615</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Mouse C-Peptide ELISA</td>
			<td style="width:123px;">ALPCO</td>
			<td style="width:344px;">80-CPTMS-E01</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Mouse Ultrasensitive Insulin ELISA</td>
			<td style="width:123px;">ALPCO</td>
			<td style="width:344px;">80-INSMSU-E01</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">MX35 Microtome Blades</td>
			<td style="width:123px;">ThermoFisher</td>
			<td style="width:344px;">3052835</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">NaCl</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">S7653</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">NaHCO3</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">S3817</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">NaH2PO4</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Normal Donkey Serum</td>
			<td style="width:123px;">Jackson Immuno Research</td>
			<td style="width:344px;">017-000-121</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Paraformaldehyde</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">158127</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">PBS 1X</td>
			<td style="width:123px;">Corning</td>
			<td style="width:344px;">21-040-CV</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Pdx1 antibody</td>
			<td>DSHB</td>
			<td>F6A11</td>
			<td>Monoclonal Mouse MIgG1</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Peel-A-Way Disposable Embedding Molds</td>
			<td style="width:123px;">VWR</td>
			<td style="width:344px;">15160-157</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Penicillin-Streptomycin Solution</td>
			<td style="width:123px;">Corning</td>
			<td style="width:344px;">MT30002CI</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">PMA (Phorbol 12-Myristate 13-Acetate)</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">P1585</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Protein LoBind Microcentrifuge Tubes</td>
			<td style="width:123px;">Eppendorf</td>
			<td style="width:344px;">22431081</td>
			<td style="width:167px;">1.5mL Capacity</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Recombinant Human FGF-10 Protein</td>
			<td style="width:123px;">R&#38;D Systems</td>
			<td style="width:344px;">345-FG</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Recombinant Human FGF-Acidic</td>
			<td style="width:123px;">Peprotech</td>
			<td style="width:344px;">100-17A</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Recombinant Human R-Spondin I Protein</td>
			<td style="width:123px;">R&#38;D Systems</td>
			<td style="width:344px;">4546-RS</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">BenchRocker 2D</td>
			<td style="width:123px;">Benchmark</td>
			<td style="width:344px;">BR2000</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Sucrose 500g</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">S0389</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">SuperFrost Plus Microscope Slides</td>
			<td style="width:123px;">Fisher Scientific</td>
			<td style="width:344px;">12-550-15</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Super Pap Pen</td>
			<td style="width:123px;">Electron Microscopy Sciences</td>
			<td style="width:344px;">71310</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Thermomixer R</td>
			<td style="width:123px;">Eppendorf</td>
			<td style="width:344px;">05-412-401</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Tissue Tek O.C.T. Compound</td>
			<td style="width:123px;">Sakura</td>
			<td style="width:344px;">4583</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Triton X-100</td>
			<td style="width:123px;">Sigma-Aldrich</td>
			<td style="width:344px;">T8787</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">TRIzol Reagent</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">15596018</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">TrypLE Express</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">12604039</td>
			<td style="width:167px;">(1x), no Phenol Red</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Trypan Blue Stain</td>
			<td style="width:123px;">Invitrogen</td>
			<td style="width:344px;">15250061</td>
			<td style="width:167px;">For cell counting slides</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Trypsin-EDTA (0.05%)</td>
			<td style="width:123px;">Corning</td>
			<td style="width:344px;">25-052-CI</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Trypsin-EDTA (0.25%)</td>
			<td style="width:123px;">Gibco</td>
			<td>25200072</td>
			<td style="width:167px;">Phenol Red</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Ultra-Low Attachment 24-Well Plate</td>
			<td style="width:123px;">Corning</td>
			<td>3473</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Ultra-Low Attachment Spheroid Plate 96-Well</td>
			<td style="width:123px;">Corning</td>
			<td>4520</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Vimentin Antibody</td>
			<td style="width:123px;">EMD Millipore</td>
			<td style="width:344px;">AB5733</td>
			<td style="width:167px;">Polyclonal Chicken IgY</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Vortex Genie</td>
			<td style="width:123px;">BioExpres</td>
			<td style="width:344px;">S-7350-1</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Y-27632 Dihydrochloride</td>
			<td style="width:123px;">R&#38;D Systems</td>
			<td>1254</td>
			<td style="width:167px;">Also known as ROCK inhibitor</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Zeiss 710 Confocal Microscope</td>
			<td>Zeiss</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

generation of scaffold-free, three-dimensional insulin expressing pancreatoids from mouse pancreatic progenitors in vitro

The pancreas is a complex organ composed of many different cell types that work together to regulate blood glucose homeostasis and digestion. These cell types include enzyme-secreting acinar cells, an arborized ductal system responsible for the transportation of enzymes to the gut, and hormone-producing endocrine cells. 
Endocrine beta-cells are the sole cell type in the body that produce insulin to lower blood glucose levels. Diabetes, a disease characterized by a loss or the dysfunction of beta-cells, is reaching epidemic proportions. Thus, it is essential to establish protocols to investigate beta-cell development that can be used for screening purposes to derive the drug and cell-based therapeutics. While the experimental investigation of mouse development is essential, in vivo studies are laborious and time-consuming. Cultured cells provide a more convenient platform for screening; however, they are unable to maintain the cellular diversity, architectural organization, and cellular interactions found in vivo. Thus, it is essential to develop new tools to investigate pancreatic organogenesis and physiology.
Pancreatic epithelial cells develop in the close association with mesenchyme from the onset of organogenesis as cells organize and differentiate into the complex, physiologically competent adult organ. The pancreatic mesenchyme provides important signals for the endocrine development, many of which are not well understood yet, thus difficult to recapitulate during the in vitro culture. Here, we describe a protocol to culture three-dimensional, cellular complex mouse organoids that retain mesenchyme, termed pancreatoids. The e10.5 murine pancreatic bud is dissected, dissociated, and cultured in a scaffold-free environment. These floating cells self-assemble with mesenchyme enveloping the developing pancreatoid and a robust number of endocrine beta-cells developing along with the acinar and the duct cells. This system can be used to study the cell fate determination, structural organization, and morphogenesis, cell-cell interactions during organogenesis, or for the drug, small molecule, or genetic screening.

Careful dissection of mouse embryos at e10.5 from the uterine horn should yield undamaged embryos in PBS for further dissection (Figure 1A). The gastrointestinal tract can be efficiently removed from the embryo (Figure 1B), permitting discernment of the dorsal pancreatic bud at the junction of the intestine and stomach (Figure 1C-F). The e10.5 pancre...

Watch this Scientific Journal Video about Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro at JoVE.com

Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro

Here, we present a protocol to generate insulin expressing 3D murine pancreatoids from free-floating e10.5 dissociated pancreatic progenitors and the associated mesenchyme.

Generation of Scaffold-free, Three-dimensional Insulin Expressing Pancreatoids from Mouse Pancreatic Progenitors In Vitro

The pancreas is a complex organ composed of many different cell types that work together to regulate blood glucose homeostasis and digestion. These cell ...

This method could help answer key questions in the pancreatic field by using these pancreatoids to understand how endocrine cells form in an architecturally and cellularly complex environment. The main advantage of this technique is that the pancreatoids develop endocrine cells due to the inclusion of the surrounding mesenchyme. Generally, individuals new to this method will struggle because the pancreas is very small at e10.5.And the dissection is crucial to the formation of pancreatoids to get enough non-contaminating tissue. To set up for dissection, fill an ice bucket and place a container of phosphate buffered saline in the ice. Clean two fine-tip forceps and dissection scissors with 70%ethanol.Near the dissection area, set a container with at least three borosilicate capillary tubes, a lighter, and filtered 1000 microliter pipet tips. Next, pipet at least one milliliter of 1.25 milligram per milliliter cold dispase diluted in sterilized water in the second well of a 12-well plate on ice. Pipet PBS in the first, third, and fourth wells of the 12-well plate.Also, pipet one milliliter of 0.05%trypsin in a 1.5 milliliter tube on ice. After euthanizing e10.5 timed pregnant mice in accordance with IACUC guidelines, spray the abdomen with 70%ethanol to clean the region. Then, make a V-shaped incision at the genital area of the mouse using scissors and forceps and continue the incision up to the diaphragm.Carefully excise the uterus by making an incision at the uppermost lateral portions of the uterus, pulling the organ upwards away from the mouse and following this incision down to the genital region before repeating on the opposite side. Place the excised uterus in a 10 centimeter petri dish with the cold PBS. Under a light dissection microscope, place the petri dish and carefully open the uterine tissue by placing two forceps between each embryo and peeling tissue away from the yolk sac.Transfer the embryos by grasping the yolk sac gently with forceps and placing them in a 10 centimeter petri dish with fresh, cold PBS. Place the petri dish on ice. Next, place multiple PBS drops on the 10 centimeter petri dish lid.Use these droplets to transfer the embryo during dissection as extra-embryonic tissues are removed to ensure visibility. Transfer an embryo to a PBS drop and gently remove it from the yolk sac using forceps while the remaining embryos stay in PBS on ice. Remove the head before moving the embryo to a new PBS drop using forceps to lightly scoop the embryo without damaging the tissue.In a new PBS drop, remove the four limb buds using forceps. Place the forceps into the opening where limb bud was present and gently tear only the most external tissue anteriorly. Rotate the embryo and repeat in the posterior direction, stopping at the hind limb bud.At this point, the gastrointestinal tract should be visible. The posterior region of the gastrointestinal tract has a slight bend;insert forceps behind this bend in the opening between the gastrointestinal tract and the spinal region at the body wall. Detach the gastrointestinal tract, working slowly upwards until the most anterior region is reached, where the cardiac region connects.In the following steps, it is critical to avoid the surrounding tissue in the culture, so as to not contaminate the pancreatoids with non-pancreatic tissue. However, if you do not grab the whole pancreatic bud, then the number and size of the pancreatoids will be impaired. Transfer the gastrointestinal tract to the fresh PBS droplet.Continue to remove the outer tissue surrounding the gastrointestinal tract. Once this outer tissue is removed, the pancreatic bud can be visualized posterior to the liver buds, in between the stomach and intestine. Then, take forceps and gently pinch the tissue beneath the protruding bud in the intestine and slightly lift the pancreatic bud off.After pinching the region where the bud connects to the intestine, the bud is separated. Wash one time in a new PBS bubble before transferring the bud into the first well of the 12-well plate and cold PBS on ice. Repeat until all of the buds are collected from the embryos and placed in the first well of the 12-well plate.Next, place the 12 well dish under the light dissection microscope. Count the number of pancreatic buds successfully dissected to later calculate the split ratio. Place a filtered 1000 microliter pipet tip into the pipet with the capillary tube attached.Flame sterilize the capillary tube and create a bend in the tube for the ease of use. Use the capillary to transfer the buds to the second well containing cold dispase solution for two minutes before transferring to the third well containing clean PBS. Pipet the buds up and down and transfer them to the fourth well containing clean PBS.Finally, using the capillary device, transfer the buds to the 1.5 milliliter tube with 0.05%trypsin. Place the tube in the pre-warmed 37 degrees celsius shaker and shake at 1, 500 RPM for four to five minutes. After vortexing for approximately 10 seconds, immediately place the tube in the centrifuge and spin for five minutes at 200g.Cautiously remove all but approximately 50 microliters of solution as to not disturb the centrifuged cells. For every bud collected at 400 microliters of organogenesis media to the centrifuged cells, pulse vortex three times and plate 100 microliters per well of a low-attachment 96 well plate, splitting buds at a one to four ratio. Check under the microscope to visualize dissociated cells freely floating.Then place the culture dish in a 37 degrees celsius incubator with 5%carbon dioxide on a rocker at medium speed. Careful dissection of mouse embryos at e10.5 from the uterine horn should yield undamaged embryos in PBS for further dissection. The gastrointestinal tract can be efficiently removed from the embryo, permitting discernment of the dorsal pancreatic bud at the junction of the intestine and stomach.In organogenesis media, these free-floating scaffold-free cells self-assemble and organize into three-dimensional pancreatoids that grow and persist for at least 10 days in culture. The application of a protein kinase C activator at high concentrations alters the morphology of developing pancreatoids, leading to loosely associated epithelial cells and increased branching. Additionally, the use of transgenic animals allows visualization of cells as they differentiate in real time.To assess the association of pancreatic mesenchyme tissue with pancreatic epithelial cells, immunostaining can be performed for markers of each tissue. Immunostaining of a duct marker with an endocrine marker and nuclei, reveal multi-lineage formation in pancreatoids. A mesenchyme marker co-stained with a pancreatic progenitor marker shows that the mesenchyme envelops the pancreatoid.Beta cell development is revealed by staining for the epithelial marker and the beta cell marker. Using quantitative PCR analysis, transcripts of progenitors and differentiating cells can be assessed, such as progenitor genes and differentiated markers. Once mastered, this technique can be done in approximately one hour, including prep time, if it is performed properly.After watching this video, you should have a good understanding of how to perform the dissection to obtain pancreatic tissue from 10.5 mice to generate pancreatoids. While attempting this procedure, it's important to remember to carefully remove the GI tract from the embryos, otherwise it will be very difficult to find the pancreatic bud. Following this procedure, other methods like GSIS and ELISA can be performed in order to answer additional questions, like how much insulin or C-peptide is produced after glucose stimulation.After its development, this technique paved the way for us to explore the morphological consequences of PKC activation using small molecules. A way of further implementing this system to study the effect of transcription factor of expression and even to perform important epistasis experiments.

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Developmental Biology

8.9K visualizações.  Baylor College of Medicine. This method could help answer key questions in the pancreatic field by using these pancreatoids to understand how endocrine cells form in an architecturally and cellularly complex environment. The main advantage of this technique is that the pancreatoids develop endocrine cells due to the inclusion of the surrounding mesenchyme. Generally, individuals new to this method will struggle because the pancreas is very small at e10.5.And the dissection is crucial to the formation of pancreato...