Induction of an Inflammatory Response in Primary Hepatocyte Cultures from Mice

Summary

Here, we show an enzymatic approach to isolate primary hepatocytes from adult mice, and we describe the quantification of an inflammatory response using ELISA and real-time PCR.

Abstract

The liver plays a decisive role in the regulation of systemic inflammation. In chronic kidney disease in particular, the liver reacts in response to the uremic milieu, oxidative stress, endotoxemia and the decreased clearance of circulating proinflammatory cytokines by producing a large number of acute-phase reactants. Experimental tools to study inflammation and the underlying role of hepatocytes are crucial to understand the regulation and contribution of hepatic cytokines to a systemic acute phase response and a prolonged pro-inflammatory scenario, especially in an intricate setting such as chronic kidney disease. Since studying complex mechanisms of inflammation in vivo remains challenging, resource-intensive and usually requires the usage of transgenic animals, primary isolated hepatocytes provide a robust tool to gain mechanistic insights into the hepatic acute-phase response. Since this in vitro technique features moderate costs, high reproducibility and common technical knowledge, primary isolated hepatocytes can also be easily used as a screening approach. Here, we describe an enzymatic-based method to isolate primary murine hepatocytes, and we describe the assessment of an inflammatory response in these cells using ELISA and quantitative real-time PCR.

Introduction

Chronic kidney disease (CKD) can be defined as a state of acute and chronic inflammation¹. In patients with CKD, serum levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23) progressively rise in order to maintain serum phosphate homeostasis². Increased serum FGF23 levels are independently associated with cardiovascular morbidity and mortality among patients who are beginning hemodialysis treatment^3,4. Furthermore, several clinical studies have shown a strong correlation between elevated FGF23 levels and serum levels of C-reactive protein (CRP), I....

Protocol

All animal protocols and experimental procedures were approved by the Institutional Animal Care and Use Committee (IACUC) of the University of Miami Miller School of Medicine.

1. Preparation

1. Preheat liver perfusion media and liver digest media in a water bath at 37 °C.
2. Set up a perfusion pump (30 mL/min). Carefully prefill the tubing system of the pump with liver perfusion media. Avoid any air bubbles in the system and prepare the stereotactic microscope.
3. Coat cell culture dishes using collagen type I according to the manufacturer's protocol.

2. Liver Recovery

Results

Histology

Representative light microscopy images of primary isolated and cultured cells are depicted in Figure 1A. Immunocytochemical analysis demonstrates that isolated hepatocytes highly express albumin (red) as well as fibroblast growth factor receptor 4 (FGFR4) (green). Nuclei are stained with 4',6-diamidino-2-phenylindole (DAPI) (blue). (Figure 1B).

Discussion

Isolating primary hepatocytes from mice is a fast, inexpensive and reliable tool to study inflammatory responses ex vivo. If performed correctly, results can be easily generated and reproduced in a timely and cost-efficient manner. The following points should be carefully assessed in order to ensure a successful isolation.

The surgical incision and the cannulation of the IVC should be performed under general anesthesia and not after euthanasia. A young, inexperienced investigator will.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Consumables
Cell Strainer 70 μm Nylon cell strainer	Falcon	352350
BD Insyte Autoguard	BD	381412
50 mL Polypropylene Conical Tube	Falcon	352098
100 6-inch Cotton Tipped Applicators	Puritan	806-WC
1cc U-100 Insulin Syringe 28 G 1/2	Becton Dickinson	329420
Tissue Culture Dish 100 x 20 mm Style	Corning	353003
6 well Cell Culture Cluster	Costar	3516
5/0 Black Braided Surgical Silk (100 yards)	LOOK	SP115
Name	Company	Catalog Number	Comments
Equipment
Minipuls 3 Perfusion Pump	Gilson	F155007
Hemacytometer Kits, Propper	VWR	48300-474
Hemacytometer Cover Glasses, Propper	VWR	48300-470
Surgical Scissers - Sharp/Blunt	F.S.T.	14001-12
Iris Scissors-ToughCut Straight	F.S.T.	14058-11
Dumont SS-45 Forceps	F.S.T.	11203-25
Student Tissue Forceps	F.S.T.	991121-12
Name	Company	Catalog Number	Comments
Reagents
Acetic acid solution, 2.0 N	Sigma	A8976-100ML
Isoflurane, USP 250 mL	Piramal Healthcare	66794-013-25
KetaVed 1,000 mg/10 mL (100 mg/mL)	VEDCO	50989-161-06
Xylazine 100 mg/mL	AnaSed Injection	139-236
Willams' Medium E (1x)	gibco	12551-032
Liver Perfusion Medium (1x)	gibco	17701-038
Liver Digest Medium (1x)	Life Technologies	17703034
Primary Hepatocyte Thawing and Plating Supplements	Life Technologies	CM3000
Primary Hepatocyte Maintenance Supplements	Life Technologies	CM4000
Phosphate Buffer Saline (PBS) pH 7.4	ThermoFisher scientific	10010031
Collagen Type 1	Corning	354236
Trypan Blue Solution	VWR	45000-717