Ultrasonic-augmented Primary Adult Fibroblast Isolation

Summary

We present a protocol to isolate primary adult fibroblasts in an easy, fast and reliable way, performable by beginners (e.g., students). The procedure combines enzymatic tissue digestion and mechanical agitation with ultrasonic waves to obtain primary fibroblasts. The protocol can easily be adapted to specific experimental requirements (e.g., human tissue).

Abstract

Primary adult fibroblasts have become an important tool to study fibrosis, fibroblast interactions and inflammation in all body tissues. Since primary fibroblasts cannot divide indefinitely due to myofibroblast differentiation or senescence induction, new cultures must be established regularly. However, there are several obstacles to overcome during the processes of developing a reliable isolation protocol and primary fibroblast isolation itself: the method’s degree of difficulty (especially for beginners), the risk of bacterial contamination, the required time until primary fibroblasts can be used for experiments, and subsequent cell quality and viability. In this study, a fast, reliable and easy-to-learn protocol to isolate and culture primary adult fibroblasts from mouse heart, lung, liver and kidney combining enzymatic digestion and ultrasonic agitation is provided.

Introduction

Fibroblasts are flat, spindle-shaped cells with multiple stellate processes and an extensive rough endoplasmic reticulum^1,2. An average fibroblast measures 30 - 100 µm and has a life span of 57 ± 3 days^1,3. The average cell cycle duration of human fibroblasts ranges from 16 - 48 h depending on the culture conditions⁴. There is evidence that the replicative capacity and functional quality of cultured primary fibroblasts negatively correlates with the donor age, suggesting that younger donors (animals or patien....

Protocol

The following protocol follows the institutional animal care guidelines of Technische Universität Dresden, Germany (File number: T 2014/4) as well as internationally accepted animal care guidelines (FELASA)¹⁷. Figure 1 visualizes the cell isolation process.

1. Preparing the setup, material and media

1. Prepare cell culture medium, PBS solution, collagenase blend stock solution (reconstitute 50 mg of lyophilized collagenase blend in 12 mL of sterile ultrapure water), and 0.25% trypsin solution.
2. Warm up the medium, the PBS and the trypsin solution to 37 °C.

Results

The ability of this protocol to isolate adult fibroblasts from solid murine tissue was demonstrated. Viable fibroblasts were obtained that could be used for subsequent experiments such as immunofluorescence staining or proliferation experiments (Figure 2D-F, Figure 5A).

Adult fibroblasts are flat spindle-shaped cells with multiple cellular processes that typically grow in monolayers^1.......

Discussion

Compared to immortalized fibroblast cell lines, primary fibroblasts offer several advantages. They can be isolated cost effectively in high quality and quantity. Furthermore, primary cultures offer the possibility to study cells from multiple individuals, which increases the reliability of the obtained results and decreases the likelihood of merely studying cell culture artifacts. Continuous generation of new primary cultures prevents genetic alterations which commonly occur after repeated passaging²¹

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
0.25% Trypsin-EDTA	Sigma-Aldrich, St. Louis, USA	T4049-100ML
Antibiotics	Gibco-Life Technologies, Carlsbad, USA	Gibco LS15140148	Penicillin/ Streptomycin (10,000 U/mL)
Cell culture hood	Thermo Fisher Scientific, Waltham, USA	51023608	HeraSafe KSP15
Cell culture incubator	Thermo Fisher Scientific, Waltham, USA	50049176	BBD 6220
Cell culture plates	Thermo Fisher Scientific, Waltham, USA	depends on vessel	6-, 12-, 24-wells Nunclon surface
Cell culture suction	VACUUBRAND GMBH + CO KG, Wertheim, Germany	20727400	BVC professional suction
Cell strainer (mesh)	Corning, Tewksbury, USA	431750	40 µm Nylon
Centrifuge	Thermo Fisher Scientific, Waltham, USA	75007213	Megafuge 8R
Cordless pipetting controller	Hirschmann, Eberstadt, Germany	9907200	Pipetus
Disposable pipette tips	Sigma-Aldrich, St. Louis, USA	depends on volume	SafeSeal tips for pipettes (10 µL, 20 µL, 100 µL, 200 µL, 1000 µL)
Disposable plastic pipettes	Sigma-Aldrich, St. Louis, USA	depends on volume	5 mL, 10 mL, 25 mL, 50 mL
Disposable sterile scalpel	Myco Medical, Cary, USA	n.a.	Techno cut
Dulbeccos Modified Eagle Medium (DMEM)	Thermo Fisher Scientific, Waltham, USA	41965-062	High glucose
Eppendorf tubes	Eppendorf, Hamburg, Germany	depends on volume	50 µL, 500 µL, 1.500µL, 2.000 µL
Fetal calf serum (FCS)	Sigma-Aldrich, St. Louis, USA	F2442-50ML
Collagenase blend	Sigma-Aldrich, St. Louis, USA	5401020001	Liberase TL Research Grade
Petri dish 6 cm	Sigma-Aldrich, St. Louis, USA	P5481-500EA
Phosphate Buffered Saline (PBS)	Sigma-Aldrich, St. Louis, USA	D8537-500ML	500 mL
Senescence detection kit	Abcam, Cambridge, UK	ab65351
Shaker/ Vortex	IKA, Staufen im Breisgau, Germany	n.a.	MS2 Minishaker (subsequent model: Ident-Nr.: 0020016017)
Sterile plastic tubes	Thermo Fisher Scientific, Waltham, USA	Falcon 352095	BD Falcon tubes (15 mL, 50 mL)
Ultrasonic water bath	BANDELIN electronic GmbH & Co. KG, Berlin, Germany	312	Sonorex RK100H
Surgical scissors (atraumatic)	Aesculap AG, Tuttlingen, Germany	NR 82
Surgical scissors	Aesculap AG, Tuttlingen, Germany	eq 1060.09
Surgical forceps	Aesculap AG, Tuttlingen, Germany	BD577