This work was supported by the Alexander von Humboldt Foundation Sofja Kovalevskaja Award to VLK.

<ol>
	<li>Dolle, 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=Successful+isolation+of+liver+progenitor+cells+by+aldehyde+dehydrogenase+activity+in+naive+mice.">Successful isolation of liver progenitor cells by aldehyde dehydrogenase activity in naive mice.</a> Hepatology. 55 (2), 540-552 (2012).</li><li>Dolle, 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=The+quest+for+liver+progenitor+cells:+a+practical+point+of+view.">The quest for liver progenitor cells: a practical point of view.</a> J Hepatol. 52 (1), 117-129 (2010).</li><li>Dorrell, 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=Surface+markers+for+the+murine+oval+cell+response.">Surface markers for the murine oval cell response.</a> Hepatology. 48 (4), 1282-1291 (2008).</li><li>Gouw, A. S., Clouston, A. D., Theise, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ductular+reactions+in+human+liver:+diversity+at+the+interface.">Ductular reactions in human liver: diversity at the interface.</a> Hepatology. 54 (5), 1853-1863 (2011).</li><li>Tarlow, B. D., Finegold, M. J., Grompe, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clonal+tracing+of+Sox9++liver+progenitors+in+mouse+oval+cell+injury.">Clonal tracing of Sox9+ liver progenitors in mouse oval cell injury.</a> Hepatology. 60 (1), 278-289 (2014).</li><li>Shin, 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=Foxl1-Cre-marked+adult+hepatic+progenitors+have+clonogenic+and+bilineage+differentiation+potential.">Foxl1-Cre-marked adult hepatic progenitors have clonogenic and bilineage differentiation potential.</a> Genes Dev. 25 (11), 1185-1192 (2011).</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 (1), 34-41 (2011).</li><li>Font-Burgada, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hybrid+Periportal+Hepatocytes+Regenerate+the+Injured+Liver+without+Giving+Rise+to+Cancer.">Hybrid Periportal Hepatocytes Regenerate the Injured Liver without Giving Rise to Cancer.</a> Cell. 162 (4), 766-779 (2015).</li><li>Kuramitsu, 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=Failure+of+fibrotic+liver+regeneration+in+mice+is+linked+to+a+severe+fibrogenic+response+driven+by+hepatic+progenitor+cell+activation.">Failure of fibrotic liver regeneration in mice is linked to a severe fibrogenic response driven by hepatic progenitor cell activation.</a> Am J Pathol. 183 (1), 182-194 (2013).</li><li>Pritchard, M. T., Nagy, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hepatic+fibrosis+is+enhanced+and+accompanied+by+robust+oval+cell+activation+after+chronic+carbon+tetrachloride+administration+to+Egr-1-deficient+mice.">Hepatic fibrosis is enhanced and accompanied by robust oval cell activation after chronic carbon tetrachloride administration to Egr-1-deficient mice.</a> Am J Pathol. 176 (6), 2743-2752 (2010).</li><li>Spee, 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=Characterisation+of+the+liver+progenitor+cell+niche+in+liver+diseases:+potential+involvement+of+Wnt+and+Notch+signalling.">Characterisation of the liver progenitor cell niche in liver diseases: potential involvement of Wnt and Notch signalling.</a> Gut. 59 (2), 247-257 (2010).</li><li>Eckert, 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=Podoplanin+discriminates+distinct+stromal+cell+populations+and+a+novel+progenitor+subset+in+the+liver.">Podoplanin discriminates distinct stromal cell populations and a novel progenitor subset in the liver.</a> Am J Physiol Gastrointest Liver Physiol. 310 (1), G1-G12 (2016).</li><li>Epting, C. 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=Stem+cell+antigen-1+is+necessary+for+cell-cycle+withdrawal+and+myoblast+differentiation+in+C2C12+cells.">Stem cell antigen-1 is necessary for cell-cycle withdrawal and myoblast differentiation in C2C12 cells.</a> J Cell Sci. 117 (Pt 25), 6185-6195 (2004).</li><li>Tirnitz-Parker, J. E., Tonkin, J. N., Knight, B., Olynyk, J. K., Yeoh, G. C. <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+immortalisation+of+hepatic+oval+cells+from+adult+mice+fed+a+choline-deficient,+ethionine-supplemented+diet.">Isolation, culture and immortalisation of hepatic oval cells from adult mice fed a choline-deficient, ethionine-supplemented diet.</a> Int J Biochem Cell Biol. 39 (12), 2226-2239 (2007).</li><li>Rountree, C. 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=A+CD133-expressing+murine+liver+oval+cell+population+with+bilineage+potential.">A CD133-expressing murine liver oval cell population with bilineage potential.</a> Stem Cells. 25 (10), 2419-2429 (2007).</li><li>Rountree, C. B., Ding, W., Dang, H., Vankirk, C., Crooks, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+CD133++liver+stem+cells+for+clonal+expansion.">Isolation of CD133+ liver stem cells for clonal expansion.</a> J Vis Exp. (56), (2011).</li><li>Sidney, L. E., McIntosh, O. D., Hopkinson, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phenotypic+Change+and+Induction+of+Cytokeratin+Expression+During+In+Vitro+Culture+of+Corneal+Stromal+Cells.">Phenotypic Change and Induction of Cytokeratin Expression During In Vitro Culture of Corneal Stromal Cells.</a> Invest Ophthalmol Vis Sci. 56 (12), 7225-7235 (2015).</li><li>Hass, R., Kasper, C., Bohm, S., Jacobs, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Different+populations+and+sources+of+human+mesenchymal+stem+cells+(MSC):+A+comparison+of+adult+and+neonatal+tissue-derived+MSC.">Different populations and sources of human mesenchymal stem cells (MSC): A comparison of adult and neonatal tissue-derived MSC.</a> Cell Commun Signal. 9, 12 (2011).</li><li>Schmelzer, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+hepatic+stem+cells+from+fetal+and+postnatal+donors.">Human hepatic stem cells from fetal and postnatal donors.</a> J Exp Med. 204 (8), 1973-1987 (2007).</li></ol>

The authors have no competing financial interests.

Liver inflammation and injury of different origins trigger regenerative processes in the liver that are accompanied by progenitor cell expansion and activation2,3. These liver progenitor cells possess stem cell characteristics and likely play a significant role in the pathomechanism of various liver diseases.
The heterogeneity of liver progenitor cells has long been suggested. The re-evaluation of liver progenitor subsets using a novel...

Liver regeneration is mostly associated with the self-renewal capacity of hepatocytes. Nevertheless, chronic liver injuries occur with progenitor cell activation and expansion, which have been associated with their ability to differentiate into hepatocytes and cholangiocytes1,2,3,4. This is especially relevant because, during chronic injuries, hepatocyte proliferation is not effective. Despite multiple genetic tracing studies targeting progenitor cells, their role in liver regeneration remains controversial5,6,7,8. Moreover, the activation of progenitor cells has been linked to increased fibrotic response in the liver, which raises questions about their exact role during injuries9,10.
The heterogeneous nature of the progenitor cell compartment has long been suggested by gene expression studies that isolated progenitor cells expressing a single surface marker using microdissection or cell sorting-based methods1,11. Indeed, recently, a novel surface marker combination using gp38 (podoplanin) unequivocally linked previous single markers of progenitor cells to various subsets12. Importantly, these subsets not only differed in their surface marker expression but also exhibited functional alterations during injuries12.
Multiple animal models have been utilized to investigate progenitor cell activation and liver regeneration. It seems that the various injury types promote the activation of differing subsets of progenitor cells12. This might explain the phenotypic divergence of the ductular reaction observed in humans4. Thus, the complex phenotypic and functional analyses of progenitor cells are pivotal to understand their role in injuries and the true significance of the ductular reaction in liver diseases.
Besides surface marker combinations, the crucial differences in cell isolation protocols further complicate the conclusions based on previous studies2. A substantial amount of studies addressed the role of progenitor cells that greatly differ in their isolation protocol (e.g., liver dissociation (enzyme combination and duration of the process), density medium, and centrifugation speed)2. An optimized isolation technique, providing better viability for rare cell populations and reflective of subset composition, has been developed and published recently12. The aim of this article is to provide a more detailed protocol of this liver cell isolation procedure and the subset analysis to allow for the proper reproduction of the technique. Additionally, the protocol includes a comparison with the previous isolation method to demonstrate the differences compared to the new protocol.

<table><tbody><tr><td>RPMI</td><td>Life Technologies</td><td>21875-034</td><td></td></tr><tr><td>phenol red free DMEM</td><td>Life Technologies</td><td>31053-028</td><td></td></tr><tr><td>FBS</td><td>Life Technologies</td><td>10270-106</td><td></td></tr><tr><td>Collagenase P</td><td>Sigma-Aldrich</td><td>11249002001</td><td></td></tr><tr><td>DNAse-I</td><td>Sigma-Aldrich</td><td>10104159001</td><td></td></tr><tr><td>Dispase</td><td>Life Technologies</td><td>17105041</td><td></td></tr><tr><td>ACK Lysing Buffer</td><td>Life Technologies</td><td>A10492-01</td><td></td></tr><tr><td>HBSS</td><td>Life Technologies</td><td>14025-050</td><td></td></tr><tr><td>PBS</td><td>Sigma-Aldrich</td><td>D8537</td><td></td></tr><tr><td>Sodium Azide</td><td>Sigma-Aldrich</td><td>S2002</td><td>Prepare 1% stock solution</td></tr><tr><td>10% BSA</td><td>Miltenyi Biotec</td><td>130-091-376</td><td></td></tr><tr><td>autoMACS Rinsing Solution</td><td>Miltenyi Biotec</td><td>130-091-222</td><td>add 0.5% (v/v) BSA and store on ice</td></tr><tr><td>Phenol-red free DMEM</td><td>Sigma-Aldrich</td><td>D1145</td><td></td></tr><tr><td>counting Beads Count Bright</td><td>Life Technologies</td><td>C36950</td><td></td></tr><tr><td>PI</td><td>Miltenyi Biotec</td><td>130-093-233</td><td></td></tr><tr><td>FcR Blocking Reagent</td><td>Miltenyi Biotec</td><td>130-092-575</td><td></td></tr><tr><td>anti-CD31 MicroBeads</td><td>Miltenyi Biotec</td><td>130-097-418</td><td></td></tr><tr><td>anti-CD45 MicroBeads</td><td>Miltenyi Biotec</td><td>130-052-301</td><td></td></tr><tr><td>Dead Cell Removal Kit</td><td>Miltenyi Biotec</td><td>130-090-101</td><td></td></tr><tr><td>anti-Biotin MicroBeads</td><td>Miltenyi Biotec</td><td>130-090-485</td><td></td></tr><tr><td>CD64 Purified</td><td>BioLegend</td><td>139302</td><td>Dilution: 1:100</td></tr><tr><td>CD16/32 Purified</td><td>BioLegend</td><td>101302</td><td>Dilution: 1:100</td></tr><tr><td>CD45 APC/Cy7</td><td>BioLegend</td><td>103116</td><td>Dilution: 1:200, marks hematopoetic cells</td></tr><tr><td>CD31 Biotin</td><td>BioLegend</td><td>102504</td><td>Dilution: 1:200, marks endothelial cells</td></tr><tr><td>ASGPR1 Purified</td><td>Bio-Techne</td><td>AF2755-SP</td><td>Dilution: 1:100, marks hepatocytes</td></tr><tr><td>Podoplanin APC</td><td>BioLegend</td><td>127410</td><td>Dilution: 1:1,400, marks progenior cells</td></tr><tr><td>Podoplanin Biotin</td><td>BioLegend</td><td>127404</td><td>Dilution: 1:1,400</td></tr><tr><td>CD133 PE</td><td>Miltenyi Biotec</td><td>130-102-210</td><td>use 3 &amp;micro;L, marks progenitor cells</td></tr><tr><td>CD133 Biotin</td><td>BioLegend</td><td>141206</td><td>Dilution: 1:100</td></tr><tr><td>CD34 Biotin</td><td>eBioScience</td><td>13-0341-81</td><td>Dilution: 1:100</td></tr><tr><td>CD90.2 Pacific Blue</td><td>BioLegend</td><td>140306</td><td>Dilution: 1:800</td></tr><tr><td>CD157 PE</td><td>BioLegend</td><td>140203</td><td>Dilution: 1:600</td></tr><tr><td>EpCAM Brilliant Violet 421</td><td>BioLegend</td><td>118225</td><td>Dilution: 1:100</td></tr><tr><td>Sca-1 Biotin</td><td>Miltenyi Biotec</td><td>130-101-885</td><td>use 10 &amp;micro;L</td></tr><tr><td>Mouse IgG2b, &amp;kappa; PE</td><td>BioLegend</td><td>400311</td><td></td></tr><tr><td>Rat IgG1 PE</td><td>BioLegend</td><td>400407</td><td></td></tr><tr><td>Rat IgG2b, &amp;kappa; APC/Cy7</td><td>BioLegend</td><td>400624</td><td></td></tr><tr><td>Rat IgG2a, &amp;kappa; Biotin</td><td>BioLegend</td><td>400504</td><td></td></tr><tr><td>Rat IgG2a, &amp;kappa; Brilliant Violet 421</td><td>BioLegend</td><td>400535</td><td></td></tr><tr><td>Syrian Hamster IgG APC</td><td>BioLegend</td><td>402012</td><td></td></tr><tr><td>Syrian Hamster IgG Biotin</td><td>BioLegend</td><td>402004</td><td></td></tr><tr><td>Normal Goat IgG Control Purified</td><td>Bio-Techne</td><td>AB-108-C</td><td></td></tr><tr><td>Donkey anti-Goat IgG Alexa Fluor 488</td><td>Life Technologies</td><td>A11055</td><td>Dilution: 1:800</td></tr><tr><td>Streptavidin Alexa Fluor 405</td><td>Life Technologies</td><td>S32351</td><td>Dilution: 1:400</td></tr><tr><td>100 &amp;micro;m Filter mesh</td><td>A. Hartenstein</td><td>PAS3</td><td></td></tr><tr><td>LS Column</td><td>Miltenyi Biotec</td><td>130-042-401</td><td></td></tr><tr><td>QuadroMACS separator</td><td>Miltenyi Biotec</td><td>130-090-976</td><td></td></tr><tr><td>MACSQuant Analyzer 10</td><td>Miltenyi Biotec</td><td>130-096-343</td><td></td></tr><tr><td>AutoMACS Pro Separator</td><td>Miltenyi Biotec</td><td>130-092-545</td><td></td></tr><tr><td>FACS AriaTMIII</td><td>BD Biosciences</td><td></td><td></td></tr><tr><td>FACSDiva sofware</td><td>BD Biosciences</td><td></td><td></td></tr><tr><td>Polypropylene Round bottom tube</td><td>Falcon</td><td>352063</td><td></td></tr><tr><td>Rneasy plus mini kit</td><td>Qiagen</td><td>74134</td><td>RLT lysis buffer is included</td></tr></tbody></table>

isolation and enrichment of liver progenitor subsets identified by a novel surface marker combination

During chronic liver injuries, progenitor cells expand in a process called ductular reaction, which also entails the appearance of inflammatory cellular infiltrate and epithelial cell activation. The progenitor cell population during such inflammatory reactions has mostly been investigated using single surface markers, either by histological analysis or by flow cytometry-based techniques. However, novel surface markers identified various functionally distinct subsets within the liver progenitor/stem cell compartment. The method presented here describes the isolation and detailed flow cytometry analysis of progenitor subsets using novel surface marker combinations. Moreover, it demonstrates how the various progenitor cell subsets can be isolated with high purity using automated magnetic and FACS sorting-based methods. Importantly, novel and simplified enzymatic dissociation of the liver allows for the isolation of these rare cell populations with a high viability that is superior in comparison to other existing methods. This is especially relevant for further studying progenitor cells in vitro or for isolating high-quality RNA to analyze the gene expression profile.

The procedure presented here for the digestion of the liver using a novel mixture of enzymes results in a single-cell suspension containing parenchymal and non-parenchymal liver cells (Figures 1 and 2a). After the ACK-lysing of red blood cells, the direct flow cytometry analysis of the single-cell suspension is possible (Figures 1 and 2). The gating strategy involves the exclusion of doublets and dead cells (Figur...

Watch this Scientific Journal Video about Isolation and Enrichment of Liver Progenitor Subsets Identified by a Novel Surface Marker Combination at JoVE.com

Isolation and Enrichment of Liver Progenitor Subsets Identified by a Novel Surface Marker Combination

Liver injuries are accompanied by progenitor cell expansion that represents a heterogeneous cell population. Novel classification of this cellular compartment allows for the distinguishing of multiple subsets. The method described here illustrates the flow cytometry analysis and high purity isolation of various subsets that can be used for further assays.

During chronic liver injuries, progenitor cells expand in a process called ductular reaction, which also entails the appearance of inflammatory cellular ...

isolation-enrichment-liver-progenitor-subsets-identified-novel

Research

JoVE Journal

Developmental Biology

10.9K Views.  Saarland University Medical Center. Liver injuries are accompanied by progenitor cell expansion that represents a heterogeneous cell population. Novel classification of this cellular compartment allows for the distinguishing of multiple subsets. The method described here illustrates the flow cytometry analysis and high purity isolation of various subsets that can be used for further assays.

Video: Isolation and Enrichment of Liver Progenitor Subsets Identified by a Novel Surface Marker Combination

Efficient Differentiation of Human Pluripotent Stem Cells into Liver Cells

The liver detoxifies harmful substances, secretes vital proteins, and executes key metabolic activities, thus sustaining life. Consequently, liver failure&#8212;which can be caused by chronic alcohol intake, hepatitis, acute poisoning, or other insults&#8212;is a severe condition that can culminate in bleeding, jaundice, coma, and eventually death. However, approaches to treat liver failure, as well as studies of liver function and disease, have been stymied in part by the lack of a plentiful supply of human liver cells. To this end, this protocol details the efficient differentiation of human pluripotent stem cells (hPSCs) into hepatocyte-like cells, guided by a developmental roadmap that describes how liver fate is specified across six consecutive differentiation steps. By manipulating developmental signaling pathways to promote liver differentiation and to explicitly suppress the formation of unwanted cell fates, this method efficiently generates populations of human liver bud progenitors and hepatocyte-like cells by days 6 and 18 of PSC differentiation, respectively. This is achieved through the temporally-precise control of developmental signaling pathways, exerted by small molecules and growth factors in a serum-free culture medium. Differentiation in this system occurs in monolayers and yields hepatocyte-like cells that express characteristic hepatocyte enzymes and have the ability to engraft a mouse model of chronic liver failure. The ability to efficiently generate large numbers of human liver cells in vitro has ramifications for treatment of liver failure, for drug screening, and for mechanistic studies of liver disease.

This protocol details a monolayer, serum-free method to efficiently generate hepatocyte-like cells from human pluripotent stem cells (hPSCs) in 18 days. This entails six steps as hPSCs sequentially differentiate into intermediate cell-types such as the primitive streak, definitive endoderm, posterior foregut and liver bud progenitors before forming hepatocyte-like cells.

The liver detoxifies harmful substances, secretes vital proteins, and executes key metabolic activities, thus sustaining life. Consequently, liver ...

Isolation of CD133+ Liver Stem Cells for Clonal Expansion

Liver stem cell, or oval cells, proliferate during chronic liver injury, and are proposed to differentiate into both hepatocytes and cholangiocytes. In addition, liver stem cells are hypothesized to be the precursors for a subset of liver cancer, Hepatocellular carcinoma. One of the primary challenges to stem cell work in any solid organ like the liver is the isolation of a rare population of cells for detailed analysis. For example, the vast majority of cells in the liver are hepatocytes (parenchymal fraction), which are significantly larger than non-parenchymal cells. By enriching the specific cellular compartments of the liver (i.e. parenchymal and non-parenchymal fractions), and selecting for CD45 negative cells, we are able to enrich the starting population of stem cells by over 600-fold.The proceduresdetailed in this report allow for a relatively rare population of cells from a solid organ to be sorted efficiently. This process can be utilized to isolateliver stem cells from normal murine liver as well as chronic liver injury models, which demonstrate increased liver stem cell proliferation. This method has clear advantages over standard immunohistochemistry of frozen or formalin fixed liver as functional studies using live cells can be performed after initial co-localization experiments. To accomplish the procedure outlined in this report, a working relationship with a research based flow-cytometry core is strongly encouraged as the details of FACS isolation are highly dependent on specialized instrumentation and a strong working knowledge of basic flow-cytometry procedures. The specific goal of this process is to isolate a population of liver stem cells that can be clonally expanded in vitro.

Here we describe the isolation of CD133 expressing liver stem cells and cancer stem cells from whole murine liver, a process that requires tissue digestion, cell enrichment, and flow cytometry isolation. We include methods for advanced single cell isolation and clonal expansion.

Liver stem cell, or oval cells, proliferate during chronic liver injury, and are proposed to differentiate into both hepatocytes and cholangiocytes. In ...

Biology

Identification and Isolation of Oligopotent and Lineage-committed Myeloid Progenitors from Mouse Bone Marrow

Myeloid progenitors that yield neutrophils, monocytes and dendritic cells (DCs) can be identified in and isolated from the bone marrow of mice for hematological and immunological analyses. For example, studies of the cellular and molecular properties of myeloid progenitor populations can reveal mechanisms underlying leukemic transformation, or demonstrate how the immune system responds to pathogen exposure. Previously described flow cytometry strategies for myeloid progenitor identification have enabled significant advances in many fields, but the fractions they identify are very heterogeneous. The most commonly used gating strategies define bone marrow fractions that are enriched for the desired populations, but also contain large numbers of &#34;contaminating&#34; progenitors. Our recent studies have resolved much of this heterogeneity, and the protocol we present here permits the isolation of 6 subpopulations of oligopotent and lineage-committed myeloid progenitors from 2 previously described bone marrow fractions. The protocol describes 3 stages: 1) isolation of bone marrow cells, 2) enrichment for hematopoietic progenitors by magnetic-activated cell sorting (lineage depletion by MACS), and 3) identification of myeloid progenitor subsets by flow cytometry (including fluorescence-activated cell sorting, FACS, if desired). This approach permits progenitor quantification and isolation for a variety of in vitro and in vivo applications, and has already yielded novel insight into pathways and mechanisms of neutrophil, monocyte, and DC differentiation.

We demonstrate how to identify and isolate 6 subsets of myeloid progenitors from murine bone marrow using a combination of magnetic and fluorescence sorting (MACS and FACS). This protocol can be used for in vitro culture assays (methylcellulose or liquid cultures), in vivo adoptive transfer experiments, and RNA/protein analyses.

Myeloid progenitors that yield neutrophils, monocytes and dendritic cells (DCs) can be identified in and isolated from the bone marrow of mice for ...

Immunology and Infection

Phenotypic Analysis and Isolation of Murine Hematopoietic Stem Cells and Lineage-committed Progenitors

The bone marrow is the principal site where HSCs and more mature blood cells lineage progenitors reside and differentiate in an adult organism. HSCs constitute a minute cell population of pluripotent cells capable of generating all blood cell lineages for a life-time1. The molecular dissection of HSCs homeostasis in the bone marrow has important implications in hematopoiesis, oncology and regenerative medicine. We describe the labeling protocol with fluorescent antibodies and the electronic gating procedure in flow cytometry to score hematopoietic progenitor subsets and HSCs distribution in individual mice (Fig. 1). In addition, we describe a method to extensively enrich hematopoietic progenitors as well as long-term (LT) and short term (ST) reconstituting HSCs from pooled bone marrow cell suspensions by magnetic enrichment of cells expressing c-Kit. The resulting cell preparation can be used to sort selected subsets for in vitro and in vivo functional studies (Fig. 2).
Both trabecular osteoblasts2,3 and sinusoidal endothelium4 constitute functional niches supporting HSCs in the bone marrow. Several mechanisms in the osteoblastic niche, including a subset of N-cadherin+ osteoblasts3 and interaction of the receptor tyrosine kinase Tie2 expressed in HSCs with its ligand angiopoietin-15 concur in determining HSCs quiescence. "Hibernation" in the bone marrow is crucial to protect HSCs from replication and eventual exhaustion upon excessive cycling activity6. Exogenous stimuli acting on cells of the innate immune system such as Toll-like receptor ligands7 and interferon-&alpha;6 can also induce proliferation and differentiation of HSCs into lineage committed progenitors. Recently, a population of dormant mouse HSCs within the lin- c-Kit+ Sca-1+ CD150+ CD48- CD34- population has been described8. Sorting of cells based on CD34 expression from the hematopoietic progenitors-enriched cell suspension as described here allows the isolation of both quiescent self-renewing LT-HSCs and ST-HSCs9. A similar procedure based on depletion of lineage positive cells and sorting of LT-HSC with CD48 and Flk2 antibodies has been previously described10. In the present report we provide a protocol for the phenotypic characterization and ex vivo cell cycle analysis of hematopoietic progenitors, which can be useful for monitoring hematopoiesis in different physiological and pathological conditions. Moreover, we describe a FACS sorting procedure for HSCs, which can be used to define factors and mechanisms regulating their self-renewal, expansion and differentiation in cell biology and signal transduction assays as well as for transplantation.

A method to analyse the distribution of bone marrow hematopoietic progenitors in flow cytometry as well as to efficiently isolate highly purified hematopoietic stem cells (HSCs) is described. The isolation procedure is essentially based on magnetic enrichment of c-Kit+ cells and cell sorting to purify HSCs for cellular and molecular studies.

The bone marrow is the principal site where HSCs and more mature blood cells lineage progenitors reside and differentiate in an adult organism. HSCs ...

Human Liver Spheroids from Peripheral Blood for Liver Disease Studies

Human liver cells can form a three-dimensional (3D) structure capable of growing in culture for some weeks, preserving their functional capacity. Due to their nature to cluster in the culture dishes with low or no adhesive characteristics, they form aggregates of multiple liver cells that are called human liver spheroids. The forming of 3D liver spheroids relies on the natural tendency of hepatic cells to aggregate in the absence of an adhesive substrate. These 3D structures possess better physiological responses than cells, which are closer to an in vivo environment. Using 3D hepatocyte cultures has numerous advantages when compared with classical two-dimensional (2D) cultures, including a more biologically relevant microenvironment, architectural morphology that reassembles natural organs as well as a better prediction regarding disease state and in vivo-like responses to drugs. Various sources can be used to generate spheroids, like primary liver tissue or immortalized cell lines. The 3D liver tissue can also be engineered by using human embryonic stem cells (hESCs) or induced pluripotent stem cells (hiPSCs) to derive hepatocytes. We have obtained human liver spheroids using blood-derived pluripotent stem cells (BD-PSCs) generated from unmanipulated peripheral blood by activation of human membrane-bound GPI-linked protein and differentiated to human hepatocytes. The BD-PSCs-derived human liver cells and human liver spheroids were analyzed by light microscopy and immunophenotyping using human hepatocyte markers.

Here we present a non-genetic method to generate human autologous liver spheroids using mononuclear cells isolated from steady-state peripheral blood.

Human liver cells can form a three-dimensional (3D) structure capable of growing in culture for some weeks, preserving their functional capacity. Due to ...

Bioengineering

Protocol for Isolation of Primary Human Hepatocytes and Corresponding Major Populations of Non-parenchymal Liver Cells

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic Stellate cells (HSC). Two-dimensional (2D) culture of primary human hepatocyte (PHH) is still considered as the &#34;gold standard&#34; for in vitro testing of drug metabolism and hepatotoxicity. It is well-known that the 2D monoculture of PHH suffers from dedifferentiation and loss of function. Recently it was shown that hepatic NPC play a central role in liver (patho-) physiology and the maintenance of PHH functions. Current research focuses on the reconstruction of in vivo tissue architecture by 3D- and co-culture models to overcome the limitations of 2D monocultures. Previously we published a method to isolate human liver cells and investigated the suitability of these cells for their use in cell cultures in Experimental Biology and Medicine1. Based on the broad interest in this technique the aim of this article was to provide a more detailed protocol for the liver cell isolation process including a video, which will allow an easy reproduction of this technique.
Human liver cells were isolated from human liver tissue samples of surgical interventions by a two-step EGTA/collagenase P perfusion technique. PHH were separated from the NPC by an initial centrifugation at 50 x g. Density gradient centrifugation steps were used for removal of dead cells. Individual liver cell populations were isolated from the enriched NPC fraction using specific cell properties and cell sorting procedures. Beside the PHH isolation we were able to separate KC, LEC and HSC for further cultivation.
Taken together, the presented protocol allows the isolation of PHH and NPC in high quality and quantity from one donor tissue sample. The access to purified liver cell populations could allow the creation of in vivo like human liver models.

A technique to isolate human hepatocytes and non-parenchymal liver cells from the same donor is described. The different liver cell types build the basis for functional liver models and tissue engineering. This new method aims to isolate liver cells in a high yield and viability.

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic ...

Isolation of Regenerating Hepatocytes after Partial Hepatectomy in Mice

Partial hepatectomy has been widely used to investigate liver regeneration in mice, but the isolation of high yields of viable hepatocytes for downstream single-cell applications is challenging. A marked accumulation of lipids within regenerating hepatocytes is observed during the first 2 days of normal liver regeneration in mice. This so-called transient regeneration-associated steatosis (TRAS) is temporary but partially overlaps the major proliferative phase. Density-gradient purification is the backbone of most existing protocols for the isolation of primary hepatocytes. As gradient purification relies on the density and size of cells, it separates non-steatotic from steatotic hepatocyte populations. Therefore, fatty hepatocytes often are lost, yielding non-representative hepatocyte fractions. 
The presented protocol describes an easy and reliable method for the in vivo isolation of regenerating hepatocytes regardless of their lipid content. Hepatocytes from male C57BL/6 mice are isolated 24-48 h after hepatectomy by a classic two-step collagenase perfusion approach. A standard peristaltic pump drives the warmed solutions via the catheterized inferior vena cava into the remnant, using a retrograde perfusion technique with outflow through the portal vein. Hepatocytes are dissociated by collagenase for their release from the Glisson's capsule. After washing and careful centrifugation, the hepatocytes can be used for any downstream analyses. In conclusion, this paper describes a straightforward and reproducible technique for the isolation of a representative population of regenerating hepatocytes after partial hepatectomy in mice. The method may also aid the study of fatty liver disease.

Lipid-laden hepatocytes are inherent to liver regeneration but are usually lost upon density-gradient centrifugation. Here, we present an optimized cell isolation protocol that retains steatotic hepatocytes, yielding representative populations of regenerating hepatocytes after partial hepatectomy in mice.

Partial hepatectomy has been widely used to investigate liver regeneration in mice, but the isolation of high yields of viable hepatocytes for downstream ...

Medicine

Hepatic Progenitor Specification from Pluripotent Stem Cells using a Defined Differentiation System

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to shortages in donor organ availability. Organ scarcity also affects the routine supply of human hepatocytes for basic research and the clinic. Therefore, the development of renewable sources of human liver progenitor cells is desirable and is the goal of this study. To be able to effectively generate and deploy human liver progenitors on a large scale, a reproducible hepatic progenitor differentiation system was developed. This protocol aids experimental reproducibility between users in a range of cell cultureware formats and permits differentiations using both, human embryonic and induced pluripotent stem cell lines. These are important advantages over current differentiation systems that will enhance the basic research and may pave the way towards clinical product development.

The goal of this article is to provide a standardized approach to induce human hepatic progenitor differentiation from pluripotent stem cells. The development of this procedure with ready-to-use media formulations offer the user a facile system to generate human liver cells for biomedical research and translation.

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to ...

Isolation and Enrichment of Human Lung Epithelial Progenitor Cells for Organoid Culture

Epithelial organoid models serve as valuable tools to study the basic biology of an organ system and for disease modeling. When grown as organoids, epithelial progenitor cells can self-renew and generate differentiating progeny that exhibit cellular functions similar to those of their in vivo counterparts. Herein we describe a step-by-step protocol to isolate region-specific progenitors from human lung and generate 3D organoid cultures as an experimental and validation tool. We define proximal and distal regions of the lung with the goal of isolating region-specific progenitor cells. We utilized a combination of enzymatic and mechanical dissociation to isolate total cells from the lung and trachea. Specific progenitor cells were then fractionated from the proximal or distal origin cells using fluorescence associated cell sorting (FACS) based on cell type-specific surface markers, such as NGFR&#160;for sorting basal cells and HTII-280 for sorting alveolar type II cells. Isolated basal or alveolar type II progenitors were used to generate 3D organoid cultures. Both distal and proximal progenitors formed organoids with a colony forming efficiency of 9-13% in distal region and 7-10% in proximal region when plated 5000 cell/well on day 30. Distal organoids maintained HTII-280+ alveolar type II cells in culture whereas proximal organoids differentiated into ciliated and secretory cells by day 30. These 3D organoid cultures can be used as an experimental tool for studying the cell biology of lung epithelium and epithelial mesenchymal interactions, as well as for the development and validation of therapeutic strategies targeting epithelial dysfunction in a disease.

This article provides a detailed methodology for tissue dissociation and cellular fractionation approaches allowing enrichment of viable epithelial cells from proximal and distal regions of the human lung. Herein these approaches are applied for the functional analysis of lung epithelial progenitor cells through the use of 3D organoids culture models.

Epithelial organoid models serve as valuable tools to study the basic biology of an organ system and for disease modeling. When grown as organoids, ...

Isolation and Characterization of Mouse Primary Liver Sinusoidal Endothelial Cells

Liver sinusoidal endothelial cells (LSECs) are specialized endothelial cells located at the interface between the circulation and the liver parenchyma. LSECs have a distinct morphology characterized by the presence of fenestrae and the absence of basement membrane. LSECs play essential roles in many pathological disorders in the liver, including metabolic dysregulation, inflammation, fibrosis, angiogenesis, and carcinogenesis. However, little has been published about the isolation and characterization of the LSECs. Here, this protocol discusses the isolation of LSEC from both healthy and nonalcoholic fatty liver disease (NAFLD) mice. The protocol is based on collagenase perfusion of the mouse liver and magnetic beads positive selection of nonparenchymal cells to purify LSECs. This study characterizes LSECs using specific markers by flow cytometry and identifies the characteristic phenotypic features by scanning electron microscopy. LSECs isolated following this protocol can be used for functional studies, including adhesion and permeability assays, as well as downstream studies for a particular pathway of interest. In addition, these LSECs can be pooled or used individually, allowing multi-omics data generation including RNA-seq bulk or single cell, proteomic or phospho-proteomics, and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq), among others. This protocol will be useful for investigators studying LSECs&#39; communication with other liver cells in health and disease and allow an in-depth understanding of the role of LSECs in the pathogenic mechanisms of acute and chronic liver injury.

Here we outline and demonstrate a protocol for primary mouse liver sinusoidal endothelial cell (LSEC) isolation. The protocol is based on liver collagenase perfusion, nonparenchymal cell purification by low-speed centrifugation, and CD146 magnetic bead selection. We also phenotype and characterize these isolated LSECs using flow cytometry and scanning electron microscopy.

Liver sinusoidal endothelial cells (LSECs) are specialized endothelial cells located at the interface between the circulation and the liver parenchyma. ...