Isolation of Human Hepatocytes by a Two-step Collagenase Perfusion Procedure

Summary

A modified two-step collagenase perfusion procedure for isolation of human hepatocytes is described. This method can also be applied to other mammalian livers. The isolated hepatocytes are available in high yield and viability, making them a suitable model for scientific research in areas such as liver regeneration, pharmacokinetics and toxicology.

Abstract

The liver, an organ with an exceptional regeneration capacity, carries out a wide range of functions, such as detoxification, metabolism and homeostasis. As such, hepatocytes are an important model for a large variety of research questions. In particular, the use of human hepatocytes is especially important in the fields of pharmacokinetics, toxicology, liver regeneration and translational research. Thus, this method presents a modified version of a two-step collagenase perfusion procedure to isolate hepatocytes as described by Seglen ¹.

Previously, hepatocytes have been isolated by mechanical methods. However, enzymatic methods have been shown to be superior as hepatocytes retain their structural integrity and function after isolation. This method presented here adapts the method designed previously for rat livers to human liver pieces and results in a large yield of hepatocytes with a viability of 77±10%. The main difference in this procedure is the process of cannulization of the blood vessels. Further, the method described here can also be applied to livers from other species with comparable liver or blood vessel sizes.

Introduction

A liver cell suspension can be prepared from the liver by mechanical or enzymatic methods. Mechanical methods used to prepare whole liver cells include forcing the liver through cheesecloth ², shaking a liver piece with glass beads in a Kahn shaker ³, using glass homogenizers with loose pestles ^4,5 etc. Over the years, mechanical methods have fallen out of favor due to the damage to cell membranes and the loss of function of the isolated hepatocytes ^6,7. Consequently, the use of an enzymatic method is currently the main method for isolation of hepatocytes.

Isolation of hepatocytes using a....

Protocol

1. Preparation of Perfusion and Isolation Solutions

1. Prepare the solutions required for the perfusion of the liver piece and the isolation of hepatocytes according to Table 1. Solutions can be stored at 4 °C until use.
2. Sterile filter all solutions using a 0.22 μm filter.
3. All solutions that come into contact with the liver should be sterile.

2. Preparation of Perfusion Equipment and Solutions

1. The equipment for the perfusion of the liver piece should be set up as shown in Figure 1.
2. The water bath should be set at an appropriate temperature, which is ....

Results

Perfusion Setup

The equipment required for liver perfusion should be set up according to Figure 1.

Viability and Yield of Isolated Human Hepatocytes

The average viability of isolated human hepatocytes was 77±10% and the average yield of hepatocytes was 13±11 million hepatocytes/g liver, with values expressed as means ± standard deviation. The number of hepatocyte isolations carried out to obtain these averages was 648 isolation.......

Discussion

This protocol results in the isolation of human hepatocytes with high viability and purity. In order to achieve these results, it is important to start with a suitable piece of liver. The piece of liver should have intact Glisson's capsule on all surfaces except for 1 cut surface. Another important factor is the particular batch of collagenase used, as different batches can result in marked differences in viabilities of hepatocytes after digestion ¹¹. Therefore, different batches of collagenase should be teste.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Bubble trap	Gaßner Glastechnik
Glass jacketed condenser	Gaßner Glastechnik
41 °C Water bath	Julabo	35723-H24/EG
37 °C Water bath	GFL	1083
Compressed gas cylinder (95 % O2/5 % CO2)	Linde
Gas permeable tubing	Neolab	2-4440
Peristaltic pump	Ismatec	IP65
Scalpel	Feather	320010
Forceps	Omnilab	5171014
Conical flasks 1 L	Schott Duran	2121654
Conical flasks 5 L	Schott Duran	2121673
Beakers	Schott Duran	2110654
200 ml centrifuge tubes	Becton Dickinson	352075
Crystallizing dish	Omnilab	5144063
Curved irrigation cannulae with ball tips	Ernst Kratz GmbH	1464LL/ 1465LL A+B/ 1472LL
Micro vascular clamps	Ernst Kratz GmbH
Büchner funnel	Carl Roth	HT38.1
Nylon mesh 210 μm	Neolab	4-1413
Nylon mesh 70 μm	Neolab	4-1419
0.22 μm sterile filters	Peske	99505
500 ml bottles	Schott Duran	2180144
1 L bottles	Schott Duran	2180154
Hemocytometer	Peske	06-0001
1.5 ml tubes	Eppendorf	0030 120,086
50 ml conical tubes	BD Biosciences	352070
Ice bucket	Neolab	1508454
Sterile Pasteur pipettes	Brand	747715
Motorised pipette filler (Pipette boy acu)	Integra	155017
Refridgerated centrifuge	Eppendorf	5810R
Laminar flow	Kendro	Hera safe-KS9
Aspirator (Low-flow surgical suction pump)	Atmos	C361
Laboratory Gas Burner	Integra	Fire Boy eco
Disposable laboratory coat	Paperlynen GmbH	MD0202414
Surgical mask with visor	Kimberly-Clark	48247
Surgical hood	Barrier	42072
Latex gloves	Semper Care	CE0321
Collagenase (Batch number NB 4G)	Serva	17465
Calcium chloride dihydrate	Merck	2382
EGTA	Sigma	E4378
Sodium chloride	Roth	9265.2
Hepes	Roth	9105.3
Potassium chloride	Serva	26868
Albumin	Biomol	01400-2
Glucose	Serva	22700
Sodium hydrogen carbonate	Serva	30180
0.4% Trypan blue solution	Lonza	17-942E
Cold storage solution	Hepacult GmbH