Rat Liver Perfusion and Primary Hepatocytes Isolation: An Old Procedure Crucial for Cutting-Edge 3D Organoids Culture

Summary

This protocol presents an optimized two-step collagenase liver perfusion technique in a rat model and shows the use of isolated hepatocytes for in vitro long-term culture of 3D organoids.

Abstract

Primary hepatocytes are a commonly used tool for in vitro liver-related studies. However, the maintenance of these cells has always been a challenge due to the rapid loss of morphology, viability, and functionality in culture. A recent approach to long-term culture is the generation of three-dimensional (3D) organoids, an in vitro tool that can recapitulate tissues in a dish based on the marvelous ability of the liver to regenerate itself. Published protocols have been designed to obtain long-term functional 3D organoids from primary adult hepatocytes (Hep-Orgs). The 3D organoid cutting-edge tool requires the ability to isolate cells from adult tissue, and this initial step is crucial for a high-quality final result. The two-step collagenase perfusion, introduced in the 1970s, is still a valid procedure to obtain single hepatocytes. The present article aims to describe all the crucial steps of the surgical procedure, thereby optimizing the primary hepatocytes isolation procedure in the rat model. Moreover, particular attention is paid to the PREPARE guidelines to increase the likelihood of successful procedures and ensure high-quality results. A detailed protocol allows researchers to speed up and optimize the downstream work to establish 3D organoids from primary adult rat hepatocytes. Compared to 2D hepatocytes, Hep-Orgs were still viable and in active proliferation at Day 15, demonstrating a long-term potential.

Introduction

Primary hepatocytes are an important and widely used tool for in vitro liver-related studies. However, their expansion and maintenance have been historically challenging, as they lose morphology and functionality after a few days in the culture¹. 2D culture is a limiting condition, in particular, for hepatocytes that have a polygonal shape and polarized structure with differentiated apical and basolateral membranes. In fact, hepatocyte adhesion to the plate interferes with their normal activity because it leads to a flat cytoskeleton with limited interaction among cells and between cells and extracellular matrix (ECM), reducing the pol....

Protocol

All procedures and animal housing were conducted according to the guidelines of the Italian Law and European Community directive. The experimental protocol was approved by the local Animal Care Committee and by the Italian Health Ministry (permit n° 321/2022-PR) according to art.31 of decree 26/2014.

1. Preparation for the animal procedure

NOTE: Please refer to Table 1 for the medium and buffer composition and to the Tabl.......

Discussion

3D-organoids are a frontier for personalized medicine and allow a long-term hepatocyte culture. The quality of this innovative technique requires a good yield of viable primary hepatocytes and well-performed liver perfusion and hepatocytes isolation. This old procedure is still widely used; however, it comprises different steps that can be challenging. Approaching the procedure, we experienced critical issues such as bacterial contamination, low liver digestion efficiency, low primary hepatocyte yield, and low hepatocyte.......

Materials

Name	Company	Catalog Number	Comments
A83-01- ALK5 Inhibitor IV	Twin Helix	T3031
B27	Thermofisher Scientific	0080085SA
CFX Connect Real-Time PCR Detection System	Bio-Rad
CHIR99021	Twin Helix	T2310
Click EdU Alexa 488 imaging kit	Thermofisher Scientific	C10499
Collagen, Type I, solution from rat tail	Merck	C3867-1VL
Dexamethasone	Merck	D4902
EGF	Merck	E9644
Fetal bovine serum (FBS)	Euroclone	ECS0180L
GELTREX LDEV FREE RGF BME	Thermofisher Scientific	A1413202
Heparin Sodium 25000 IU/5 ml	B. Braun Melsungen AG	B01AB01
HGF	Peprotech	100-39H
Insulin-Transferrin-Selenium solution 100x	Thermofisher Scientific	41400045
L-Glutamine solution	Euroclone	ECB3000D
Liver Digest Medium	Thermofisher Scientific	17703-034
Liver Perfusion Medium	Thermofisher Scientific	17701038
N2 supplement	Thermofisher Scientific	17502048
N-acetylcysteine	Merck	A9165
Nicotinamide	Merck	N-0636
Non-Essential Amino Acids	Merck	M7145
Normocin	Aurogene	ant-nr-1
PBS buffer 1X	PanReac AppliChem	A0964,9050
Penicillin-streptomycin solution 100x	Euroclone	ECB3001D
Percoll	Santa Cruz	sc-296039A
Peristaltic pump	Ismatec™	MS-4/12 Reglo Digital Pump
TNFa	Peprotech	300-01A
TRI Reagent	Merck	T9424
Tubing	Ismatec™	ID.2,79mm
Williams' E Medium, no glutamine	Thermofisher Scientific	31415029
Y27632	Twin Helix	T1725