This work was supported by grant from NIDDK (DK065949 for GG). We thank Dr. Brenda M. Jarvis and Jeff Duryea Jr. for reading the manuscript.

Animal usage follows the procedures specified in protocol M/11/181 approved by the Vanderbilt Institutional Animal Care and Use Committee for Gu. CD1 or CBA/Bl6 mice were purchased from commercial vendors and crossed in the Vanderbilt animal facility to obtain neonatal mice.
1. Preparation of Mice, Stock Solutions, and Equipment
<ol>
	<li>For the mouse cross: set up a mouse cross and record the plugging dates to aid experimental planning. CD1 mice usually give birth around day 19 after matin...

<ol>
	<li>Matsumoto, 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=Improvement+of+pancreatic+islet+cell+isolation+for+transplantation.">Improvement of pancreatic islet cell isolation for transplantation.</a> Proc (Bayl Univ Med Cent). 20 (4), 357-362 (2007).</li><li>Zmuda, E. J., Powell, C. A., Hai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+murine+islet+isolation+and+subcapsular+kidney+transplantation.">A method for murine islet isolation and subcapsular kidney transplantation.</a> J Vis Exp. 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M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+gene+expression+profiling+of+pancreatic+islets+in+mice+during+streptozotocin-induced+beta-cell+damage+and+pancreatic+Glp-1+gene+therapy.">Global gene expression profiling of pancreatic islets in mice during streptozotocin-induced beta-cell damage and pancreatic Glp-1 gene therapy.</a> Dis Model Mech. 6 (5), 1236-1245 (2013).</li><li>London, N. J., Swift, S. M., Clayton, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation,+culture+and+functional+evaluation+of+islets+of+Langerhans.">Isolation, culture and functional evaluation of islets of Langerhans.</a> Diabetes Metab. 24 (3), 200-207 (1998).</li><li>Rorsman, 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=Failure+of+glucose+to+elicit+a+normal+secretory+response+in+fetal+pancreatic+beta+cells+results+from+glucose+insensitivity+of+the+ATP-regulated+K++channels.">Failure of glucose to elicit a normal secretory response in fetal pancreatic beta cells results from glucose insensitivity of the ATP-regulated K+ channels.</a> Proc Natl Acad Sci U S A. 86 (12), 4505-4509 (1989).</li><li>Hellerstrom, C., Swenne, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+maturation+and+proliferation+of+fetal+pancreatic+beta-cells.">Functional maturation and proliferation of fetal pancreatic beta-cells.</a> Diabetes. 40 (Suppl 2), 89-93 (1991).</li><li>Blum, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+beta-cell+maturation+is+marked+by+an+increased+glucose+threshold+and+by+expression+of+urocortin+3.">Functional beta-cell maturation is marked by an increased glucose threshold and by expression of urocortin 3.</a> Nat Biotechnol. 30 (3), 261-264 (2012).</li><li>Hegre, O. 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=Nonenzymic+in+vitro+isolation+of+perinatal+islets+of+Langerhans.">Nonenzymic in vitro isolation of perinatal islets of Langerhans.</a> In Vitro. 19 (8), 611-620 (1983).</li><li>Dolen&#353;ek, J., Rupnik, M. A., Sto&#382;er, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+similarities+and+differences+between+the+human+and+the+mouse+pancreas.">Structural similarities and differences between the human and the mouse pancreas.</a> Islets. 7 (1), e102445 (2015).</li><li>White, J., White, D. 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Here, we provide a step-by-step protocol on islet isolation from pancreata that are too small for conventional perfusion. It is expected to yield islets ready for all islet-based studies such as beta-cell purification, gene expression analysis, islet beta-cell maturation, proliferation, cell stress responses, cell survival, metabolism, and functional GSIS maintenance, etc. This will be, to the best of our knowledge, the first detailed visual protocol that guides new researchers to perform islet isolation from ne...

Isolating pure pancreatic islets is essential for assaying glucose stimulated insulin secretion (GSIS) of beta cells and for islet transplantation from cadaveric donors 1-3. It is also necessary to establish endocrine gene expression in islet cells 4, 5. For this purpose, detailed protocols have been established to allow for isolation of pancreatic islets from large pancreata (6 and references therein). These methods are based on enzymatic perfusion to dissociate acinar from islet tissues, coupled with gradient separation and hand picking. Thus, islet isolation from large pancreas can be performed readily in most laboratories. On the other hand, no detailed step-by-step protocol exists to allow for the isolation of islets from pancreata that are too small to perfuse.
Studying gene expression and function of neonatal islets is important. Neonate islets have different properties from adults in insulin secretion and proliferation capability 7, 8. However, isolating islets from newly born animals, especially mice is challenging due to the small size of the newly born pancreas. The size prevents the usual perfusion process when collagenase is injected though the pancreatic duct. Indeed, several papers have presented studies along these lines, with enzyme or non-enzyme aided isolation procedures 7, 9, 10. However, detailed description of the islet isolation process with visual aid is lacking 7, 9, making it a challenge for most researchers to perform similar studies. 
We have explored several different conditions that yield high quality islets from neonatal mice. Here we present a protocol that is expected to help researchers learn the key details in the islet isolation process. This protocol is applicable to mouse pancreas up to two weeks of age, after which perfusion can be performed for routine islet isolation. Islets can be directly used for insulin secretion and gene expression assays.

<table border="0" cellpadding="0" cellspacing="0" width="769">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Collagenase&#160; Type IV</td>
			<td style="width:253px;">Sigma Aldrich, St Louis, MO</td>
			<td style="width:128px;">C5138</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="61">
			<td height="61" style="height:61px;width:169px;">1X HBSS with Ca2+/Mg2+</td>
			<td style="width:253px;">Mediatech/Cellgro, Manassas, VA</td>
			<td>MT21020CV</td>
			<td style="width:219px;">If HBSS wihout Ca2+/Mg2+ is obtained, CaCl2 and MgSO4 can be added to 1.26 and 0.5 mM, respectively.&#160;</td>
		</tr>
		<tr height="51">
			<td height="51" style="height:51px;width:169px;">RPMI 1640 w/o glucose</td>
			<td style="width:253px;">Thermo Fisher Scientific/Life Technologies, Waltham, MA</td>
			<td>11879-020</td>
			<td style="width:219px;">Glucose needs to be added to specific levels to not interfere with seusequent islet usage.&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Glucose</td>
			<td style="width:253px;">Sigma Aldrich, St Louis, MO</td>
			<td>G-7021&#160;</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:169px;">polysucrose and sodium diatrizoate solution</td>
			<td style="width:253px;">Sigma Aldrich, St Louis, MO</td>
			<td>Histopaque-10771</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Stereoscope</td>
			<td style="width:253px;">Carl-Zeiss, Oberkochen, Germany</td>
			<td>Stemi2000</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Stereoscope</td>
			<td style="width:253px;">Leica, Wetzlar, Germany</td>
			<td>Leica M165</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Microcentrifuge</td>
			<td style="width:253px;">Eppendorf, Hauppauge, NY</td>
			<td>Centrifuge 5417C</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Centrfuge</td>
			<td style="width:253px;">Eppendorf, Hauppauge, NY</td>
			<td>Centrifuge 5810R</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">15-ml centrfuge tubes&#160;</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>89039-666</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">50-ml centrfuge tubes&#160;</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>89039-658</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Precision balance</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>VWR-225AC</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Microfuge tubes</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>87003-294</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Pipetman P1000</td>
			<td style="width:253px;">Fisher Scientific,&#160; Waltham, MA</td>
			<td>F123602</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Pipetman P20</td>
			<td style="width:253px;">Fisher Scientific,&#160; Waltham, MA</td>
			<td>F123600</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">100X15 millimeter dish</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>25384-088</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">60X15 millimeter dish</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>25384-168</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:169px;">12-well plates</td>
			<td style="width:253px;">VWR, Radnor, PA</td>
			<td>665-180</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:169px;">Scissor</td>
			<td style="width:253px;">Fine Scientific Tools, Foster City, CA</td>
			<td>14080-11</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:169px;">Tweezers</td>
			<td style="width:253px;">Fine Scientific Tools, Foster City, CA</td>
			<td>5708-5</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:169px;">CD1 mice</td>
			<td style="width:253px;">Charles River Laboratories, Wilminton, MA&#160;</td>
			<td>CD-1</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:169px;">C57BL/6J</td>
			<td style="width:253px;">The Jackson laboratory, Farmington, CT&#160;</td>
			<td>C57BL/6J</td>
			<td style="width:219px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:169px;">B6CBAF1/J</td>
			<td style="width:253px;">The Jackson laboratory, Farmington, CT&#160;</td>
			<td>B6CBAF1/J</td>
			<td style="width:219px;"></td>
		</tr>
	</tbody>
</table>

effective isolation of functional islets from neonatal mouse pancreas

Perfusion-based islet-isolation protocols from large mammalian pancreata are well established. Such protocols are readily conducted in many laboratories due to the large size of the pancreatic duct that allows for ready collagenase injection and subsequent tissue perfusion. In contrast, islet isolation from small pancreata, like that of neonatal mice, is challenging because perfusion is not readily achievable in the small pancreata. Here we describe a detailed simple procedure that recovers substantial numbers of islets from newly born mice with visual assistance. Freshly dissected whole pancreata were digested with 0.5 mg/mL collagenase IV dissolved in Hanks&#39; Balanced Salt Solution (HBSS) at 37 &#176;C, in microcentrifuge tubes. Tubes were tapped regularly to aid tissue dispersal. When most of the tissue was dispersed to small clusters around 1 mm, lysates were washed three to four times with culture media with 10% fetal bovine serum (FBS). Islet clusters, devoid of recognizable acinar tissues, can then be recovered under dissecting stereoscope. This method recovers 20 - 80 small- to large-sized islets per pancreas of newly born mouse. These islets are suitable for most conceivable downstream assays, including insulin secretion, gene expression, and culture. An example of insulin secretion assay is presented to validate the isolation process. The genetic background and degree of digestion are the largest factors determining the yield. Freshly made collagenase solution with high activity is preferred, as it aids in endocrine-exocrine isolation. The presence of cations [calcium (Ca2+) and magnesium (Mg2+)] in all solutions and fetal bovine serum in the wash/picking media are necessary for good yield of islets with proper integrity. A dissecting scope with good contrast and magnification will also help.

Under optimal conditions, the presented method can yield 20 - 80 islets from each small mouse pancreas. This number depends on the genetic background, age of mice, and the size of islets to be recovered. Among the commonly used, CD1 out-bred and C57BL/6J pure-bred mice produce less islets with smaller size than hybrids between CD1 and C57BL/6 or commercial B6CBAF1/J mice do. Direct hand picking generally gave a smaller number of islets, likely due to the exclusion of small islets that cou...

Watch this Scientific Journal Video about Effective Isolation of Functional Islets from Neonatal Mouse Pancreas at JoVE.com

Effective Isolation of Functional Islets from Neonatal Mouse Pancreas

We describe a protocol herein for isolating intact islets from neonatal mice. Pancreata were partially digested with collagenase, followed by washing and hand picking. 20 - 80 islet clusters can be obtained per pancreas from newly born mice, which are suitable for several islet studies.

Perfusion-based islet-isolation protocols from large mammalian pancreata are well established. Such protocols are readily conducted in many laboratories ...

The overall goal of this procedure is to isolate intact islets of Langerhans from the neonatal mouse pancreas. This method can help answer the key questions in adding development and function. Such as insulin excretion, gene expression, para cell survival and functional maintenance.The main advantage of this method is that it's simple and straight forward while still allowing new researchers to isolate a substantial number of intact islet for down strain studies. Begin by spraying a neonate in the supine position with 70%ethanol. Then, use tweezers to lift the skin over the abdomen and cut the skin and muscle layers longitudinally along the midline from the genitals to the ribcage.Next, transfer all of the internal organs into a 100 centimeter dish and locate the pancreas, which is a white scattered organ with the ventral portion that clings to the duodenum and the dorsal portion that clings to the stomach and spleen. Add HBSS to dish to submerge the organs so that the pancreatic tissues no longer cling to the duodenum, stomach, or spleen. Then use a pair of tweezers to peel the pancreas away from surrounding tissues.Transfer the pancreas into a new 60 millimeter dish containing HBSS and use scissors to cut one to five pancreata into five millimeter pieces or smaller. When all of the tissue has been minced, transfer the pieces into one point five milliliter microcentrifuge tubes and add collagenase working solutions to the samples. Then incubate the tissue fragments at 37 degrees celsius, inverting the tubes two times every minute.After five minutes, tap the tube to monitor the digestion status of the pieces. Continue the digestion for another ten minutes, until the lysate is cloudy and most of the pancreata appear as fragmented cell clusters less than two millimeters in diameter. At the end of the digestion, pellet the lysate by microcentrifugation and use a p1000 pipette to carefully remove the supernatent, which should appear turbid but free of cell clusters.Next, add one millileter of fresh RPMI 16/40 complete medium to the pellet. Then gently tap to resuspend the fragmented lysate pieces and invert the tube ten times. After centrifuging, invert the resuspended lysate at least two more times as just demonstrated until the supernatent is clear.Then resuspend the final pellet in one milliliter of fresh complete medium and add two milliliters of polysucrose and sodium diatrazoate at a 1.077 g/ml density to a 15 milliliter conical tube on ice. Using a Pasteur pipette, carefully layer the lysate on top of the gradient solution without mixing the layers and separate the cells by centrifugation. Transfer the medium and the islet containing interphase layers into a new 15 milliliter tube and gently but thoroughly mix the islets with ten milliliters of fresh medium for centrifugation.After a second wash and fresh complete medium, resuspend the islet and duct containing pellet in four milliliters of fresh complete medium. Now seed the islets onto a 60 millimeter dish and add five milliliters of complete medium to the cells. Transfer the dish under a dissecting microscope and turn on the bright field illumination adjusting the light intensity to approximately 50%of the maximum power.At a 50x magnification, the islets will appear as slightly pink clusters and the acinar cells and dark, irregularly shaped clusters. Using a p20 pipette tip, harvest the individual islets, taking care to avoid the acinar clusters, dispensing the islet enriched fractions in a new 60 millimeter dish containing complete medium. When all of the islets have been picked from the original dish, harvest the islets from the collection dish into a new 60 millimeter dish containing four milliliters of fresh complete medium two more times, until only pure islets are present in the final collection dish.A proper digestion and isolation will yield islets with smooth outer surfaces. Insufficient collagenase digestion can result in large, easily visualized islets that can not be completely separated from the acinar tissues, reducing the overall islet yield even though larger islets are produced. In the case of over digestion, although acinar tissues can be completely separated from the islets, islet structure is prone to be compromised resulting in rough surface islets observed under the microscope.Neonatal islets isolated by this method display high basal insulin secretion levels with glucose stimulated insulin secretion profiles typical of immature islet beta cells, suggesting that this islet isolation procedure largely conserves the functional properties of neonatal islets. Once mastered, this technique can be finished within just two hours if performed properly. When attempting the procedure, it is important to remember to precentrifuge the collagenase in order to remove any insoluble debris and to calcium and magnesium supplemented washing buffer and to use pretreated washing buffer in order to stop the tissue dissociation quickly.For in this procedure, our experiment, such as glucose stimulated insulin secretion can be performed to answer additional questions such as insulin secretion dynamics in neonatal beta cells. Also, this technique pave ways for researchers in the field of beta cell biology to do additional essays, such as gene expression or other metabolic studies. After watching this video, you should have a good understanding of how to isolate intact islets from neonatal mouse pancreas for your down strain studies.Don't forget, working with collagenase powder will be extremely hazardous, so precautions such as wearing gloves and face mask should be always taken when using this material.

effective-isolation-of-functional-islets-from-neonatal-mouse-pancreas

Research

JoVE Journal

Developmental Biology

Isolation and Cryopreservation of Neonatal Rat Cardiomyocytes

Cell culture has become increasingly important in cardiac research, but due to the limited proliferation of cardiomyocytes, culturing cardiomyocytes is difficult and time consuming. The most commonly used cells are neonatal rat cardiomyocytes (NRCMs), which require isolation every time cells are needed. The birth of the rats can be unpredictable. Cryopreservation is proposed to allow for cells to be stored until needed, yet freezing/thawing methods for primary cardiomyocytes are challenging due to the sensitivity of the cells. Using the proper cryoprotectant, dimethyl sulfoxide (DMSO), cryopreservation was achieved. By slowly extracting the DMSO while thawing the cells, cultures were obtained with viable NRCMs. NRCM phenotype was verified using immunocytochemistry staining for &#945;-sarcomeric actinin. In addition, cells also showed spontaneous contraction after several days in culture. Cell viability after thawing was acceptable at 40-60%. In spite of this, the methods outlined allow one to easily cryopreserve and thaw NRCMs. This gives researchers a greater amount of flexibility in planning experiments as well as reducing the use of animals.

The isolation of neonatal rat cardiomyocytes is a time consuming and unpredictable procedure. This study describes methods for cryopreservation and thawing of neonatal rat cardiomyocytes that allows for more efficient use of cells. The thawed NRCMs can be used for various experiments without the need for performing isolations each time.

Cell culture has become increasingly important in cardiac research, but due to the limited proliferation of cardiomyocytes, culturing cardiomyocytes is ...

In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas

Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. However, it is still unknown whether stem and progenitor cells exist in the adult pancreas. Research strategies using cre-lox lineage-tracing in adult mice have yielded results that either support or refute the idea that beta cells can be generated from the ducts, the presumed location where adult pancreatic progenitors may reside. These in vivo cre-lox lineage-tracing methods, however, cannot answer the questions of self-renewal and multi-lineage differentiation-two criteria necessary to define a stem cell. To begin addressing this technical gap, we devised 3-dimensional colony assays for pancreatic progenitors. Soon after our initial publication, other laboratories independently developed a similar, but not identical, method called the organoid assay. Compared to the organoid assay, our method employs methylcellulose, which forms viscous solutions that allow the inclusion of extracellular matrix proteins at low concentrations. The methylcellulose-containing assays permit easier detection and analyses of progenitor cells at the single-cell level, which are critical when progenitors constitute a small sub-population, as is the case for many adult organ stem cells. Together, results from several laboratories demonstrate in vitro self-renewal and multi-lineage differentiation of pancreatic progenitor-like cells from mice. The current protocols describe two methylcellulose-based colony assays to characterize mouse pancreatic progenitors; one contains a commercial preparation of murine extracellular matrix proteins and the other an artificial extracellular matrix protein known as a laminin hydrogel. The techniques shown here are 1) dissociation of the pancreas and sorting of CD133+Sox9/EGFP+ ductal cells from adult mice, 2) single cell manipulation of the sorted cells, 3) single colony analyses using microfluidic qRT-PCR and whole-mount immunostaining, and 4) dissociation of primary colonies into single-cell suspensions and re-plating into secondary colony assays to assess self-renewal or differentiation.

In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas

In vitro colony assays to detect self-renewal and differentiation of progenitor cells isolated from adult murine pancreas are devised. In these assays, pancreatic progenitors give rise to cell colonies in 3-dimensional space in methylcellulose-containing semi-solid medium. Protocols for handling single cells and characterization of individual colonies are described.

Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. ...

Isolation of Murine Embryonic Hemogenic Endothelial Cells

The specification of hemogenic endothelial cells from embryonic vascular endothelium occurs during brief developmental periods within distinct tissues, and is necessary for the emergence of definitive HSPC from the murine extra embryonic yolk sac, placenta, umbilical vessels, and the embryonic aorta-gonad-mesonephros (AGM) region. The transient nature and small size of this cell population renders its reproducible isolation for careful quantification and experimental applications technically difficult. We have established a fluorescence-activated cell sorting (FACS)-based protocol for simultaneous isolation of hemogenic endothelial cells and HSPC during their peak generation times in the yolk sac and AGM. We demonstrate methods for dissection of yolk sac and AGM tissues from mouse embryos, and we present optimized tissue digestion and antibody conjugation conditions for maximal cell survival prior to identification and retrieval via FACS. Representative FACS analysis plots are shown that identify the hemogenic endothelial cell and HSPC phenotypes, and describe a methylcellulose-based assay for evaluating their blood forming potential on a clonal level.

Hematopoietic stem and progenitor cells (HSPC) derive from specialized (hemogenic) endothelial cells during development, yet little is known about the process by which some endothelial cells specify to become blood forming. We demonstrate a flow-cytometry based method allowing simultaneous isolation of hemogenic endothelial cells and HSPC from murine embryonic tissues.

The specification of hemogenic endothelial cells from embryonic vascular endothelium occurs during brief developmental periods within distinct tissues, ...

Isolation of Type I and Type II Pericytes from Mouse Skeletal Muscles

Pericytes are perivascular multipotent cells that show heterogeneity in different organs or even within the same tissue. In skeletal muscles, there are at least two pericyte subpopulations (called type I and type II), which express different molecular markers and have distinct differentiation capabilities. Using NG2-DsRed and Nestin-GFP double-transgenic mice, type I (NG2-DsRed+Nestin-GFP-) and type II (NG2-DsRed+Nestin-GFP+) pericytes have been successfully isolated. However, the availability of these double-transgenic mice prevents the widespread use of this purification method. This work describes an alternative protocol that allows for the easy and simultaneous isolation of type I and type II pericytes from skeletal muscles. This protocol utilizes the fluorescence-activated cell sorting (FACS) technique and targets PDGFR&#946;, rather than NG2, together with the Nestin-GFP signal. Following isolation, type I and type II pericytes show distinct morphologies. In addition, type I and type II pericytes isolated with this new method, like those isolated from the double-transgenic mice, are adipogenic and myogenic, respectively. These results suggest that this protocol can be used to isolate pericyte subpopulations from skeletal muscles and possibly from other tissues.

This work describes a FACS-based protocol that allows for easy and simultaneous isolation of type I and type II pericytes from skeletal muscles.

Pericytes are perivascular multipotent cells that show heterogeneity in different organs or even within the same tissue. In skeletal muscles, there are at ...

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound (30/45MHZ) System

Congenital heart defects (CHDs) are the most common cause of childhood morbidity and early mortality. Prenatal detection&#160;of the underlying molecular mechanisms of CHDs is&#160;crucial for inventing new preventive and therapeutic strategies. Mutant mouse models are powerful tools to discover new&#160;mechanisms&#160;and environmental stress modifiers that drive cardiac development and their potential&#160;alteration in CHDs. However, efforts to establish the causality of these putative contributors have been limited to histological&#160;and molecular studies&#160;in non-survival animal experiments, in which&#160;monitoring the key physiological and hemodynamic parameters is&#160;often absent. Live imaging technology has become an essential tool to establish the&#160;etiology of CHDs. In particular,&#160;ultrasound imaging can be used prenatally without surgically exposing the fetuses,&#160;allowing maintaining&#160;their baseline physiology while monitoring the impact of environmental stress&#160;on the hemodynamic and structural aspects of cardiac chamber development. Herein, we use the High-Frequency Ultrasound (30/45)&#160;system to examine the cardiovascular system in fetal mice at E18.5 in utero at the baseline and in response to prenatal hypoxia exposure. We demonstrate the feasibility of the system to measure cardiac chamber size, morphology, ventricular function, fetal heart rate, and umbilical artery flow indices, and their alterations in fetal mice exposed to systemic chronic hypoxia in utero in real time.

Fetal Mouse Cardiovascular Imaging Using a High-frequency Ultrasound 30/45MHZ System

High-frequency ultrasound imaging of the fetal mouse has improved imaging resolution and can provide precise non-invasive characterization of cardiac development and structural defects. The protocol outlined herein is designed to perform real-time fetal mice echocardiography in vivo.

Congenital heart defects (CHDs) are the most common cause of childhood morbidity and early mortality. Prenatal detection&#160;of the underlying molecular ...

Efficient Generation of Pancreas/Duodenum Homeobox Protein 1+ Posterior Foregut/Pancreatic Progenitors from hPSCs in Adhesion Cultures

Human pluripotent stem cell (hPSC)-derived pancreatic cells are a promising cell source for regenerative medicine and a platform to study human developmental processes. Stepwise directed differentiation that recapitulates developmental processes is one of the major ways to generate pancreatic cells including pancreas/duodenum homeobox protein 1+ (PDX1+) pancreatic progenitor cells. Conventional protocols initiate the differentiation with small colonies shortly after the passage. However, in the state of colonies or aggregates, cells are prone to heterogeneities, which might hamper the differentiation to PDX1+ cells. Here, we present a detailed protocol to differentiate hPSCs into PDX1+ cells. The protocol consists of four steps and initiates the differentiation by seeding dissociated single cells. The induction of SOX17+ definitive endoderm cells was followed by the expression of two primitive gut tube markers, HNF1&#946; and HNF4&#945;, and eventual differentiation into PDX1+ cells. The present protocol provides easy handling and may improve and stabilize the differentiation efficiency of some hPSC lines that were previously found to differentiate inefficiently into endodermal lineages or PDX1+ cells.

Efficient Generation of Pancreas/Duodenum Homeobox Protein 1+ Posterior Foregut/Pancreatic Progenitors from hPSCs in Adhesion Cultures

Here, we present a detailed protocol to differentiate human pluripotent stem cells (hPSCs) into pancreas/duodenum homeobox protein 1+ (PDX1+) cells for the generation of pancreatic lineages based on the non-colony type monolayer growth of dissociated single cells. This method is suitable for producing homogenous hPSC-derived cells, genetic manipulation and screening.

Human pluripotent stem cell (hPSC)-derived pancreatic cells are a promising cell source for regenerative medicine and a platform to study human ...

Isolation and Differentiation of Primary Myoblasts from Mouse Skeletal Muscle Explants

Primary myoblasts are undifferentiated proliferating precursors of skeletal muscle. They can be cultured and studied as muscle precursors or induced to differentiate into later stages of muscle development. The protocol provided here describes a robust method for the isolation and culture of a highly proliferative population of myoblast cells from young adult mouse skeletal muscle explants. These cells are useful for the study of the metabolic properties of skeletal muscle of different mouse models, as well as in other downstream applications such as transfection with exogenous DNA or transduction with viral expression vectors. The level of differentiation and metabolic profile of these cells depends on the length of exposure, and composition of the media used to induce myoblast differentiation. These methods provide a robust system for the study of mouse muscle cell metabolism ex vivo. Importantly, unlike in vivo models, the methods described here provide a cell population that can be expanded and studied with high levels of reproducibility.

Myoblasts are proliferating precursor cells that differentiate to form polynucleated myotubes and eventually skeletal muscle myofibers. Here, we present a protocol for efficient isolation and culture of primary myoblasts from young adult mouse skeletal muscles. The method enables molecular, genetic, and metabolic studies of muscle cells in culture.

Primary myoblasts are undifferentiated proliferating precursors of skeletal muscle. They can be cultured and studied as muscle precursors or induced to ...

Rapid Isolation of Single Cells from Mouse and Human Teeth

Mouse and human teeth represent challenging organs for quick and efficient cell isolation for single-cell transcriptomic or other applications. The dental pulp tissue, rich in the extracellular matrix, requires a long and tedious dissociation process that is typically beyond the reasonable time for single-cell transcriptomics. For avoiding artificial changes in gene expression, the time elapsed from euthanizing an animal until the analysis of single cells needs to be minimized. This work presents a fast protocol enabling to obtain single-cell suspension from mouse and human teeth in an excellent quality suitable for scRNA-seq (single-cell RNA-sequencing). This protocol is based on accelerated tissue isolation steps, enzymatic digestion, and subsequent preparation of final single-cell suspension. This enables fast and gentle processing of tissues and allows using more animal or human samples for obtaining cell suspensions with high viability and minimal transcriptional changes. It is anticipated that this protocol might guide researchers interested in performing the scRNA-seq not only on the mouse or human teeth but also on other extracellular matrix-rich tissues, including cartilage, dense connective tissue, and dermis.

The current protocol presents a fast, efficient, and gentle method for isolating single cells suitable for single-cell RNA-seq analysis from a continuously growing mouse incisor, mouse molar, and human teeth.

Mouse and human teeth represent challenging organs for quick and efficient cell isolation for single-cell transcriptomic or other applications. The dental ...

Isolation of Whole Cell Protein Lysates from Mouse Facial Processes and Cultured Palatal Mesenchyme Cells for Phosphoprotein Analysis

Mammalian craniofacial development is a complex morphological process during which multiple cell populations coordinate to generate the frontonasal skeleton. These morphological changes are initiated and sustained through diverse signaling interactions, which often include protein phosphorylation by kinases. Here, two examples of physiologically-relevant contexts in which to study phosphorylation of proteins during mammalian craniofacial development are provided: mouse facial processes, in particular E11.5 maxillary processes, and cultured mouse embryonic palatal mesenchyme cells derived from E13.5 secondary palatal shelves. To overcome the common barrier of dephosphorylation during protein isolation, adaptations and modifications to standard laboratory methods that allow for isolation of phosphoproteins are discussed. Additionally, best practices are provided for proper analysis and quantification of phosphoproteins following western blotting of whole cell protein lysates. These techniques, particularly in combination with pharmacological inhibitors and/or murine genetic models, can be used to gain greater insight into the dynamics and roles of various phosphoproteins active during craniofacial development.

The protocol presents a method for isolating whole cell protein lysates from dissected mouse embryo facial processes or cultured mouse embryonic palatal mesenchyme cells and performing subsequent western blotting to assess phosphorylated protein levels.

Mammalian craniofacial development is a complex morphological process during which multiple cell populations coordinate to generate the frontonasal ...

Isolation of Preadipocytes from Broiler Chick Embryos

Primary preadipocytes are a valuable experimental system for understanding the molecular pathways that control adipocyte differentiation and metabolism. Chicken embryos provide the opportunity to isolate preadipocytes from the earliest stage of adipose development. This primary cell can be used to identify factors influencing preadipocyte proliferation and adipogenic differentiation, making them a valuable model for studies related to childhood obesity and control of excess fat deposition in poultry. The rapid growth of postnatal adipose tissue effectively wastes feed by allocating it away from muscle growth in broiler chickens. Therefore, methods to understand the earliest stages of adipose tissue development may provide clues to regulate this tendency and identify ways to limit adipose expansion early in life. The present study was designed to develop an efficient method for isolation, primary culture, and adipogenic differentiation of preadipocytes isolated from developing adipose tissue of commercial broiler (meat-type) chick embryos. The procedure has been optimized to yield cells with high viability (~98%) and increased capacity to differentiate into mature adipocytes. This simple method of embryonic preadipocyte isolation, culture, and differentiation supports functional analyses of fat growth and development in early life.

The present protocol describes a simple method for isolating preadipocytes from adipose tissue in broiler embryos. This method enables isolation with high yield, primary culture, and adipogenic differentiation of preadipocytes. Oil Red O staining and lipid/DNA stain measured the adipogenic ability of isolated cells induced with differentiation media.

Primary preadipocytes are a valuable experimental system for understanding the molecular pathways that control adipocyte differentiation and metabolism. ...