This study was supported by the Swiss National Fond (project grant 310030_189262).

<ol>
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M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+omics+analysis+reveals+functional+diversification+of+hepatocytes+during+liver+regeneration.">Single-cell omics analysis reveals functional diversification of hepatocytes during liver regeneration.</a> JCI Insight. 5 (22), (2020).</li><li>Chembazhi, U. V., Bangru, S., Hernaez, M., Kalsotra, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+plasticity+balances+the+metabolic+and+proliferation+dynamics+of+a+regenerating+liver.">Cellular plasticity balances the metabolic and proliferation dynamics of a regenerating liver.</a> Genome Research. 31 (4), 576-591 (2021).</li><li>Fiegel, H. C., Kaufmann, P. M., Kneser, U., Kluth, D., Rogiers, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Priming+of+hepatocytes+for+cell+culture+by+partial+hepatectomy+prior+to+cell+isolation.">Priming of hepatocytes for cell culture by partial hepatectomy prior to cell isolation.</a> Journal of Tissue Engineering. 6 (6), 619-626 (2000).</li><li>Roche, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Liberase TM Research Grade. , (2020).</li><li>Giugliano, 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=Hepatitis+C+virus+infection+induces+autocrine+interferon+signaling+by+human+liver+endothelial+cells+and+release+of+exosomes,+which+inhibits+viral+replication.">Hepatitis C virus infection induces autocrine interferon signaling by human liver endothelial cells and release of exosomes, which inhibits viral replication.</a> Gastroenterology. 148 (2), 392-402 (2015).</li><li>Shetty, 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=Common+lymphatic+endothelial+and+vascular+endothelial+receptor-1+mediates+the+transmigration+of+regulatory+T+cells+across+human+hepatic+sinusoidal+endothelium.">Common lymphatic endothelial and vascular endothelial receptor-1 mediates the transmigration of regulatory T cells across human hepatic sinusoidal endothelium.</a> The Journal of Immunology. 186 (7), 4147-4155 (2011).</li><li>Edwards, S., Lalor, P. 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The authors declare that they have no competing interests.

The published protocol provides a reliable and straightforward method to isolate a high yield of normal and steatotic murine hepatocytes for single-cell downstream analyses or bulk analysis of cells following FACS sorting. The distinct advantage over density-gradient purification is that the cellular lipid content has essentially no impact on the effective yield of hepatocytes. Thus, the fraction of steatotic hepatocytes will be retained and included in downstream analyses. This is not only crucial for the study of steat...

The liver can regenerate itself even after major tissue loss. This unique regenerative capacity is explicitly illustrated by the experimental model of partial (70%) hepatectomy, first described in rats by Higgins and Anderson in 19311. In this model, 70% of the liver is surgically removed from animals by clipping off larger liver lobes. The remaining lobes then grow through compensatory hypertrophy to restore the original liver mass within about 1 week after surgery, albeit without restoration of the original liver architecture2,3. Additional hepatectomies with varying amounts of tissue removal have been developed, such as 86%-extended hepatectomy where the liver remnant is too small to recover, eventually leading to posthepatectomy liver failure (PHLF) and subsequent death in 30%-50% of the animals4,5,6. These models enable the study of normal and failed liver regeneration, depending on the amount of resected tissue (Figure 1).
Although mouse models of hepatectomies have been used successfully for many years, only recently have more advanced analytical methods allowed for a deeper insight at the single-cell level. For most of these methods, however, the presence of individual hepatocytes is a basic prerequisite. Most protocols for the isolation of primary hepatocytes are based on a two-step collagenase perfusion technique and subsequent density-gradient purification to separate viable hepatocytes from debris and non-parenchymal, as well as dead cells7,8,9. This method was first described by Berry and Friend in 196910 and adapted by Seglen and colleagues in 197211,12. However, as gradient centrifugation relies on the density and size of cells, lipid-laden hepatocytes are often lost during standard purification. While such loss may be negligible for many research questions, it is a crucial aspect for early liver regeneration. During the first 2 days, hepatocytes within the regenerating mouse liver accumulate lipids, thereby growing in size and dipping in density. This transient regeneration-associated steatosis (TRAS) serves to provide regenerative fuel and is temporary, but partially overlaps the major proliferative phase and is unevenly distributed within the liver lobules - the functional units of the liver13,14. After extended 86%-hepatectomy, however, TRAS also occurs but persists, because regeneration is stalled and lipids are not being oxidized14. Therefore, gradient-purification of hepatocytes following 70%- or 86%-hepatectomies will yield non-representative fractions, as most lipid-laden hepatocytes are lost due to their low density15.
In this modified isolation protocol, hepatocytes from C57BL/6 mice are isolated 24-48 h after hepatectomy by a classic two-step collagenase perfusion approach. Usually, cannulation and perfusion of the remnant for cell isolation are done via the portal vein. However, portovascular resistance in small remnants left after major resection is high16, and thus perfusion is delicate. Because the vena cava remains unaffected by hepatectomies, perfusion can be easily performed in the retrograde direction via cannulation of the vena cava. A standard peristaltic pump drives the warmed solutions via the catheterized inferior vena cava into the liver remnant, using retrograde perfusion with outflow through the portal vein (Supplementary Figure S1). Hepatocytes are dissociated by collagenases and released from the Glisson&#39;s capsule. After washing and careful processing of viable hepatocytes by stepwise isolation using a low-speed centrifugation approach, the hepatocytes can be used for any downstream analyses.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 Zombie green</td>
			<td>BioLegend</td>
			<td>423111</td>
			<td>Amine-reactive viability dye</td>
		</tr>
		<tr>
			<td>Attane Isoflurane ad us. vet. 99.9%</td>
			<td>Provet AG</td>
			<td>QN01AB06</td>
			<td>CAUTION: needs ventilation</td>
		</tr>
		<tr>
			<td>EDTA solution</td>
			<td>Sigma-Aldrich</td>
			<td>E8008-100ML</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Sigma-Aldrich</td>
			<td>V001229</td>
			<td>Dilute with water to 70%</td>
		</tr>
		<tr>
			<td>Fetal bovine serum (FCS)</td>
			<td>Gibco</td>
			<td>A5256701</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Hanks&#39; Balanced Salt Solution (HBSS), Ca2+, Mg2+, phenol red</td>
			<td>Sigma-Aldrich</td>
			<td>H9269-6x600ML</td>
			<td>For digestion/preservation</td>
		</tr>
		<tr>
			<td>Hanks&#39; Balanced Salt solution (HBSS), w/o Ca2+, w/o Mg2+, no phenol red</td>
			<td>Sigma-Aldrich</td>
			<td>H6648-6x500ML</td>
			<td>For perfusion buffer</td>
		</tr>
		<tr>
			<td>HEPES solution, 1 M</td>
			<td>Sigma-Aldrich</td>
			<td>83264-100ML-F</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Histoacryl tissue adhesive (butyl-2-cyanoacrylate)</td>
			<td>B. Braun</td>
			<td>1050052</td>
			<td>For stabilization of cannulation site</td>
		</tr>
		<tr>
			<td>Hoechst 33258 Staining Dye Solution</td>
			<td>Abcam</td>
			<td>ab228550</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Liberase Research Grade</td>
			<td>Roche</td>
			<td>5401119001</td>
			<td>Lyophilized collagenases I/II</td>
		</tr>
		<tr>
			<td>NaCl 0.9% 500 mL Ecotainer</td>
			<td>B. Braun</td>
			<td>123</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Paralube Vet Ointment</td>
			<td>Dechra</td>
			<td>17033-211-38</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS)</td>
			<td>Gibco</td>
			<td>A1286301</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Sudan IV &#8211; Lipid staining</td>
			<td>Sigma-Aldrich</td>
			<td>V001423</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Temgesic (Buprenorphine hydrochloride), Solution for Injection 0.3 mg/mL</td>
			<td>Indivior Europe Ltd.</td>
			<td>345928</td>
			<td>Narcotics. Store securely.</td>
		</tr>
		<tr>
			<td>Trypan blue, 0.4%, sterile-filtered</td>
			<td>Sigma-Aldrich</td>
			<td>T8154</td>
			<td>For cell counting</td>
		</tr>
		<tr>
			<td>Williams&#8217; Medium E</td>
			<td>Sigma-Aldrich</td>
			<td>W4128-500ML</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Materials</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>25 mL serological pipette, Greiner Cellstar</td>
			<td>Merck</td>
			<td>P7865</td>
			<td>-</td>
		</tr>
		<tr>
			<td>50 mL Falcon tubes</td>
			<td>TPP</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>BD Neoflon, Pro IV Catheter 26 G</td>
			<td>BD Falcon</td>
			<td>391349</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Cell scraper, rotating blade width 25 mm</td>
			<td>TPP</td>
			<td>99004</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Falcon Cell Strainer 100 &#181;m Nylon</td>
			<td>BD Falcon</td>
			<td>352360</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Fenestrated sterile surgical drape</td>
			<td>-</td>
			<td>-</td>
			<td>Reusable cloth material</td>
		</tr>
		<tr>
			<td>Filling nozzle for size 16# tubing (ID 3.1 mm)</td>
			<td>Drifton</td>
			<td>FILLINGNOZZLE#16</td>
			<td>To go into the tubes</td>
		</tr>
		<tr>
			<td>Flow cytometry tubes, 5 mL</td>
			<td>BD Falcon</td>
			<td>352008</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Male Luer to Barb, Tubing ID 3.2 mm</td>
			<td>Drifton</td>
			<td>LM41</td>
			<td>Connection tube to syringe</td>
		</tr>
		<tr>
			<td>Petri dishes, 96 x 21 mm</td>
			<td>TPP</td>
			<td>93100</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Prolene 5-0</td>
			<td>Ethicon</td>
			<td>8614H</td>
			<td>To retract the sternum</td>
		</tr>
		<tr>
			<td>Prolene 6-0</td>
			<td>Ethicon</td>
			<td>8695H</td>
			<td>For skin suture</td>
		</tr>
		<tr>
			<td>Prolene 8-0</td>
			<td>Ethicon</td>
			<td>EH7470E</td>
			<td>Ligature gall bladder</td>
		</tr>
		<tr>
			<td>Tube 16#, WT 1.6 mm, ID 3.2 mm, OD 6.4 mm</td>
			<td>Drifton</td>
			<td>SC0374T</td>
			<td>Perfusion tube</td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>BD LSRFortessa Cell Analyzer Flow Cytometer</td>
			<td>BD</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Isis rodent shaver</td>
			<td>Aesculap</td>
			<td>GT421</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Isofluran station</td>
			<td>Provet</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Low-speed centrifuge &#8211; Scanspeed 416</td>
			<td>Labogene</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Neubauer-improved counting chamber</td>
			<td>Marienfeld</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Oxygen concentrator &#8211; EverFlo</td>
			<td>Philips&#160;</td>
			<td>1020007</td>
			<td>0 &#8211; 5 L/min</td>
		</tr>
		<tr>
			<td>Pipetboy &#8211; Pipettor Turbo-Fix</td>
			<td>TPP</td>
			<td>94700</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Shenchen perfusion pump &#8211; YZ1515x</td>
			<td>Shenchen</td>
			<td>YZ1515x</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Surgical microscope &#8211; SZX9</td>
			<td>Olympus</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>ThermoLux warming mat</td>
			<td>Thermo Lux</td>
			<td>-</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Vortex Genie 2, 2700 UpM</td>
			<td>NeoLab</td>
			<td>7-0092</td>
			<td>-</td>
		</tr>
		<tr>
			<td>Water bath &#8211; Precision GP 02</td>
			<td>Thermo scientific</td>
			<td>-</td>
			<td>Adjust to 42 &#176;C</td>
		</tr>
	</tbody>
</table>

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.

TRAS peaks at 16 h post hepatectomy and gradually vanishes 32-48 h after standard hepatectomy, but persists beyond 48 h after extended hepatectomy. Macroscopically, TRAS is readily visible as a pale complexion of the liver remnant (Figure 1F) and can be observed in hepatectomized mice between 16 h and 48 h after surgery.
The estimated final yield is 10-15 &#215; 106 hepatocytes after 70%-hepatectomy and 4-9 &#215; 106 after extended 86%-hepat...

Watch this Scientific Journal Video about Isolation of Regenerating Hepatocytes after Partial Hepatectomy in Mice at JoVE.com

Isolation of Regenerating Hepatocytes after Partial Hepatectomy in Mice

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 ...

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3.8K Views.  University Hospital Zurich (USZ). 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.

Video: Isolation of Regenerating Hepatocytes after Partial Hepatectomy in Mice

A Model of Disturbed Flow-Induced Atherosclerosis in Mouse Carotid Artery by Partial Ligation and a Simple Method of RNA Isolation from Carotid Endothelium

Despite the well-known close association, direct evidence linking disturbed flow to atherogenesis has been lacking. We have recently used a modified version of carotid partial ligation methods [1,2] to show that it acutely induces low and oscillatory flow conditions, two key characteristics of disturbed flow, in the mouse common carotid artery. Using this model, we have provided direct evidence that disturbed flow indeed leads to rapid and robust atherosclerosis development in Apolipoprotein E knockout mouse [3]. We also developed a method of endothelial RNA preparation with high purity from the mouse carotid intima [3]. Using this mouse model and method, we found that partial ligation causes endothelial dysfunction in a week, followed by robust and rapid atheroma formation in two weeks in a hyperlipidemic mouse model along with features of complex lesion formation such as intraplaque neovascularization by four weeks. This rapid in vivo model and the endothelial RNA preparation method could be used to determine molecular mechanisms underlying flow-dependent regulation of vascular biology and diseases. Also, it could be used to test various therapeutic interventions targeting endothelial dysfunction and atherosclerosis in considerably reduced study duration.

This describes a partial carotid ligation surgery, which causes disturbed flow conditions and subsequent atherosclerosis development (in two weeks) with intraplaque neo-vascularization (in four weeks) in the mouse common carotid artery. We also describe a novel method of RNA isolation from the carotid intima, providing high purity endothelial RNA.

Despite the well-known close association, direct evidence linking disturbed flow to atherogenesis has been lacking. We have recently used a modified ...

Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention

One desirable endpoint of general anesthesia is the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is less straightforward than it is in human patients. A widely used behavioral surrogate for hypnosis in rodents is the loss of righting reflex (LORR), or the point at which the animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency. We have developed a system to assess LORR in 24 mice simultaneously while carefully controlling for potential confounds, including temperature fluctuations and varying gas flows. These chambers permit reliable assessment of anesthetic sensitivity as measured by latency to return of the righting reflex (RORR) following a fixed anesthetic exposure. Alternatively, using stepwise increases (or decreases) in anesthetic concentration, the chambers also enable determination of a population's sensitivity to induction (or emergence) as measured by EC50 and Hill slope. Finally, the controlled environmental chambers described here can be adapted for a variety of alternative uses, including inhaled delivery of other drugs, toxicology studies, and simultaneous real-time monitoring of vital signs.

Loss of the righting reflex has long served as a standard behavioral surrogate for unconsciousness, also called hypnosis, in laboratory animals. Alterations in volatile anesthetic sensitivity caused by pharmacological interventions can be detected with a carefully controlled high-throughput assessment system, which may be adapted for delivery of any inhaled therapeutic.

One desirable endpoint of general anesthesia is  the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is  less ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study model. As the use of mouse models are often a vital step in preclinical drug discovery and drug development1-8, it is necessary to design a system to introduce drugs into mice in a uniform, reproducible manner. Ideally, the system should permit the collection of blood samples at regular intervals over a set time course. The ability to measure drug concentrations by mass-spectrometry, has allowed investigators to follow the changes in plasma drug levels over time in individual mice1, 9, 10. In this study, paclitaxel was introduced into transgenic mice as a continuous arterial infusion over three hours, while blood samples were simultaneously taken by retro-orbital bleeds at set time points. Carotid artery infusions are a potential alternative to jugular vein infusions, when factors such as mammary tumors or other obstructions make jugular infusions impractical. Using this technique, paclitaxel concentrations in plasma and tissue achieved similar levels as compared to jugular infusion. In this tutorial, we will demonstrate how to successfully catheterize the carotid artery by preparing an optimized catheter for the individual mouse model, then show how to insert and secure the catheter into the mouse carotid artery, thread the end of the catheter out through the back of the mouse&#8217;s neck, and hook the mouse to a pump to deliver a controlled rate of drug influx. Multiple low volume retro-orbital bleeds allow for analysis of plasma drug concentrations over time.

This method was developed with the goal of delivering a steady drug solution via the carotid artery, to assess the pharmacokinetics of novel drugs in mouse models.

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

Visualization of Vascular and Parenchymal Regeneration after 70% Partial Hepatectomy in Normal Mice

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the silicone compound, via a 26 G catheter, into the portal or hepatic vein. After silicone injection, organs were explanted and prepared for ex-vivo micro-CT (&#181;CT) scanning. The silicone injection procedure is technically challenging. Achieving a successful outcome requires extensive microsurgical experience from the surgeon. One of the challenges of this procedure involves determining the adequate perfusion rate for the silicone compound. The perfusion rate for the silicone compound needs to be defined based on the hemodynamic of the vascular system of interest. Inappropriate perfusion rate can lead to an incomplete perfusion, artificial dilation and rupturing of vascular trees.
The 3D reconstruction of the vascular system was based on CT scans and was achieved using preclinical software such as HepaVision. The quality of the reconstructed vascular tree was directly related to the quality of silicone perfusion. Subsequently computed vascular parameters indicative of vascular growth, such as total vascular volume, were calculated based on the vascular reconstructions. Contrasting the vascular tree with silicone allowed for subsequent histological work-up of the specimen after &#181;CT scanning. The specimen can be subjected to serial sectioning, histological analysis and whole slide scanning, and thereafter to 3D reconstruction of the vascular trees based on histological images. This is the prerequisite for the detection of molecular events and their distribution with respect to the vascular tree. This modified silicone injection procedure can also be used to visualize and reconstruct the vascular systems of other organs. This technique has the potential to be extensively applied to studies concerning vascular anatomy and growth in various animal and disease models.

Tools used for visualizing vascular regeneration require methods for contrasting the vascular trees. This film demonstrated a delicate injection technique used to achieve optimal contrasting of the vascular trees and illustrate the potential benefits resulting from a detailed analysis of the resulting specimen using &#181;CT and histological serial sections.

A modified silicone injection procedure was used for visualization of the hepatic vascular tree. This procedure consisted of in-vivo injection of the ...

Intrasplenic Transplantation of Hepatocytes After Partial Hepatectomy in NOD.SCID Mice

Partial hepatectomy is a versatile and reproducible method to study liver regeneration and the effect of cell based therapeutics in various pathological conditions. Partial hepatectomy also facilitates the increased engraftment and proliferation of transplanted cells by accelerating neovascularization and cell migration towards the liver. Here, we describe a simple protocol for performing 30% hepatectomy and transplantation of cells in the spleen of a non-obese diabetic/severe combined immunodeficient NOD.SCID (NOD.CB17-Prkdcscid/J) mouse. 
In this procedure, two small incisions are made. The first incision is to expose and resect the left lobe of the liver, and another small incision is made to expose the spleen for the intrasplenic transplantation of cells. This procedure does not require any specialized surgical skills, and it can be completed in 5-7 minutes with less stress and pain, faster recovery, and better survival. We have demonstrated the transplantation of hepatocytes isolated from a green fluorescent protein (GFP) expressing mouse (Transgenic C57BL/6-Tg (UBC-GFP) 30Scha/J), as well as hepatocyte like cells of human origin (NeoHep) in partially hepatectomized NOD.SCID mice.

We have described a protocol for performing partial hepatectomy (PHx) and cell transplantation via spleen in NOD.SCID (NOD.CB17-Prkdcscid/J) mice. In this protocol, an incision is made to expose and resect the left lobe of the liver followed by another incision for the intrasplenic transplantation of cells.

Partial hepatectomy is a versatile and reproducible method to study liver regeneration and the effect of cell based therapeutics in various pathological ...

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. To better understand the mechanism behind these surgical procedures, a rat partial liver transplantation (PLTx) model was established for relevant surgical studies. Because of the complexity of the rat PLTx model, a protocol with detailed descriptions is required. An article published previously reported a protocol in which ex vivo hepatectomy was used to achieve 50% rat PLTx. In contrast to this protocol, we introduced a re-arterialized PLTx with an in vivo 70% hepatectomy. An updated vessel-oriented hepatectomy was incorporated into the rat PLTx to refine the microsurgical procedure. The portal veins and hepatic arteries of the left lateral lobe and the median lobe were individually dissected and ligated before removal of the liver parenchyma, thereby decreasing the probability of bleeding in the remnant liver stump. Furthermore, an end-to-side vessel anastomosis between the common hepatic artery and the enlarged proper hepatic artery was introduced to re-arterialize the hepatic artery. By using this end-to-side vessel anastomosis technique, the diameter of the anastomosis was enlarged, thereby decreasing the difficulty of hand suture and maintaining a high rate of anastomotic patency. Moreover, the cuff anastomosis of the infrahepatic vena cava was slightly modified. A section of circumferential liver parenchyma around the vena cava of a recipient was preserved during cuff anastomosis to maintain the three-dimensional shape of the vascular lumen. This section of liver parenchyma was removed after completing the anastomosis. With this modification, the step involving placement of stay sutures was omitted, thereby further shortening the cuff anastomosis time. By using this protocol of rat PLTx, a low liver enzyme level, an intact liver lobular architecture and a high survival rate were achieved after microsurgery.

Re-Arterialized Rat Partial Liver Transplantation with an in vivo Vessel-Oriented 70% Hepatectomy

Here, a protocol involving re-arterialized rat partial liver transplantation is presented. Specifically, 70% liver was resected in vivo by using an updated technique of vessel-oriented hepatectomy. The hepatic artery was reconstructed in an end-to-side manner. The cuff technique was modified to shorten the anastomosis time of the infrahepatic vena cava.

Split liver transplantation and living liver donor liver transplantation were developed in the clinic to utilize liver organs in a more efficient manner. ...

Transplantation of Adipose Tissue-Derived Stem Cell Sheet to Reduce Leakage After Partial Colectomy in A Rat Model

Anastomotic leakage is a disastrous complication after colorectal surgery. Although current methods for leakage prevention have different levels of clinical efficacy, they are until now imperfect solutions. Stem cell therapy using ASC sheets could provide a solution to this problem. ASCs are considered as promising candidates for promoting tissue healing because of their trophic and immunomodulatory properties. Here, we provide methods to produce high-density ASC sheets, that are transplanted onto a colorectal anastomosis in a rat model to reduce the leakage. ASCs formed cell sheets in thermo-responsive culture dishes that could be easily detached. On the day of the transplantation, a partial colectomy with a 5-suture colorectal anastomosis was performed. Animals were immediately transplanted with 1 ASC sheet per rat. ASC sheets adhered spontaneously to the anastomosis without any glue, suture, or any biomaterial. Animal groups were sacrificed 3 and 7 days postoperatively. Compared to transplanted animals, the incidence of anastomotic abscesses and leakage was higher in control animals. In our model, the transplantation of ASC sheets after colorectal anastomosis was successful and associated with a lower leakage rate.

The preparation and transplantation of adipose tissue derived stem cell (ASC) sheets onto insufficiently sutured colorectal anastomoses in a rat model is presented. This novel application shows that ASC sheets can reduce colorectal anastomosis leakage.

Anastomotic leakage is a disastrous complication after colorectal surgery. Although current methods for leakage prevention have different levels of ...

Isolation of Primary Mouse Hepatocytes for Nascent Protein Synthesis Analysis by Non-radioactive L-azidohomoalanine Labeling Method

Hepatocytes are parenchymal cells of the liver and engage multiple metabolic functions, including synthesis and secretion of proteins essential for systemic energy homeostasis. Primary hepatocytes isolated from the murine liver constitute a valuable biological tool to understand the functional properties or alterations occurring in the liver. Herein we describe a method for the isolation and culture of primary mouse hepatocytes by performing a two-step collagenase perfusion technique and discuss their utilization for investigating protein metabolism. The liver of an adult mouse is sequentially perfused with ethylene glycol-bis tetraacetic acid (EGTA) and collagenase, followed by the isolation of hepatocytes with the density gradient buffer. These isolated hepatocytes are viable on culture plates and maintain the majority of endowed characteristics of hepatocytes. These hepatocytes can be used for assessments of protein metabolism including nascent protein synthesis with non-radioactive reagents. We show that the isolated hepatocytes are readily controlled and comprise a higher quality and volume stability of protein synthesis linked to energy metabolism by utilizing the chemo-selective ligation reaction with a Tetramethylrhodamine (TAMRA) protein detection method and western blotting analyses. Therefore, this method is valuable for investigating hepatic nascent protein synthesis linked to energy homeostasis. The following protocol outlines the materials and methods for the isolation of high-quality primary mouse hepatocytes and detection of nascent protein synthesis.

Here, we present a protocol for the isolation of healthy and functional primary mouse hepatocytes. Instructions for detecting hepatic nascent protein synthesis by non-radioactive labeling substrate were provided to help understand the mechanisms underlying protein synthesis in the context of energy-metabolism homeostasis in the liver.

Hepatocytes are parenchymal cells of the liver and engage multiple metabolic functions, including synthesis and secretion of proteins essential for ...

Lentiviral Vector-mediated Gene Therapy of Hepatocytes Ex Vivo for Autologous Transplantation in Swine

Gene therapy is an ideal choice to cure many inborn errors of metabolism of the liver. Ex-vivo, lentiviral vectors have been used successfully in the treatment of many hematopoietic diseases in humans, as their use offers stable transgene expression due to the vector&#39;s ability to integrate into the host genome. This method demonstrates the application of ex vivo gene therapy of hepatocytes to a large animal model of hereditary tyrosinemia type I. This process consists of 1) isolation of primary hepatocytes from the autologous donor/recipient animal, 2) ex vivo gene delivery via hepatocyte transduction with a lentiviral vector, and 3) autologous transplant of corrected hepatocytes via portal vein injection. Success of the method generally relies upon efficient and sterile removal of the liver resection, careful handling of the excised specimen for isolation of viable hepatocytes sufficient for re-engrafting, high-percentage transduction of the isolated cells, and aseptic surgical procedures throughout to prevent infection. Technical failure at any of these steps will result in low yield of viable transduced hepatocytes for autologous transplant or infection of the donor/recipient animal. The pig model of human type 1 hereditary tyrosinemia (HT-1) chosen for this approach is uniquely amenable to such a method, as even a small percentage of engraftment of corrected cells will lead to repopulation of the liver with healthy cells based on a powerful selective advantage over native-diseased hepatocytes. Although this growth selection will not be true for all indications, this approach is a foundation for expansion into other indications and allows for manipulation of this environment to address additional diseases, both within the liver and beyond, while controlling for exposure to viral vector and opportunity for off-target toxicity and tumorigenicity.

Lentiviral Vector-mediated Gene Therapy of Hepatocytes Ex Vivo for Autologous Transplantation in Swine

This protocol is intended to describe porcine hepatocyte isolation and ex vivo gene delivery to cure models of metabolic diseases via autologous cell transplantation. Although this particular model enjoys unique advantages that favor successful therapy, the application is a relevant foundation to address additional diseases and indications.

Gene therapy is an ideal choice to cure many inborn errors of metabolism of the liver. Ex-vivo, lentiviral vectors have been used successfully in the ...

Isolation of Atrial Myocytes from Adult Mice

The electrophysiological properties of atrial myocytes importantly affect overall cardiac function. Alterations in the underlying ionic currents responsible for the action potential can cause pro-arrhythmic substrates that underlie arrhythmias, such as atrial fibrillation, which are highly prevalent in many conditions and disease states. Isolating adult mouse atrial cardiomyocytes for use in patch-clamp experiments has greatly advanced our knowledge and understanding of the cellular electrophysiology in the healthy atrial myocardium and in the setting of atrial pathophysiology. In addition, studies using genetic mouse models have elucidated the role of a vast array of proteins in regulating atrial electrophysiology. Here we provide a detailed protocol for the isolation of cardiomyocytes from the atrial appendages of adult mice using a combination of enzymatic digestion and mechanical dissociation of these tissues. This approach consistently and reliably yields isolated atrial cardiomyocytes that can then be used to characterize cellular electrophysiology by measuring action potentials and ionic currents in patch-clamp experiments under a number of experimental conditions.

This protocol is used to isolate single atrial cardiomyocytes from the adult mouse heart using a chunk digestion approach. This approach is used to isolate right or left atrial myocytes that can be used to characterize atrial myocyte electrophysiology in patch-clamp studies.