Isolation of Perivascular Multipotent Precursor Cell Populations from Human Cardiac Tissue

Summary

Human cardiac tissue harbours multipotent perivascular precursor cell populations that may be suitable for myocardial regeneration. The technique described here allows for the simultaneous isolation and purification of two multipotent stromal cell populations associated with native blood vessels, i.e. CD146⁺CD34^- pericytes and CD34⁺CD146^- adventitial cells, from the human myocardium.

Abstract

Multipotent mesenchymal stem/stromal cells (MSC) were conventionally isolated, through their plastic adherence, from primary tissue digests whilst their anatomical tissue location remained unclear. The recent discovery of defined perivascular and MSC cell marker expression by perivascular cells in multiple tissues by our group and other researchers has provided an opportunity to prospectively isolate and purify specific homogenous subpopulations of multipotent perivascular precursor cells. We have previously demonstrated the use of fluorescent activated cell sorting (FACS) to purify microvascular CD146⁺CD34^- pericytes and vascular CD34⁺CD146^- adventitial cells from human skeletal muscle. Herein we describe a method to simultaneously isolate these two perivascular cell subsets from human myocardium by FACS, based on the expression of a defined set of cell surface markers for positive and negative selections. This method thus makes available two specific subpopulations of multipotent cardiac MSC-like precursor cells for use in basic research and/or therapeutic investigations.

Introduction

The heart has long been considered a post-mitotic organ. However, recent studies have demonstrated the presence of limited cardiomyocyte turnover in adult human hearts¹. Native stem/progenitor cells with cardiomyocyte differentiation potential have also been identified within the myocardium in adult rodent and human hearts, including Sca-1⁺, c-kit⁺, cardiosphere-forming, and most recently, perivascular precursor cells^2,3. These cells represent attractive candidates for therapies aimed at enhancing cardiac repair/regeneration through cell transplantation or stimulation of in-situ proliferation.

Protocol

1. Processing of Human Cardiac Sample

1. Ensure that all fluids, containers, instruments, and the dedicated operational area are sterile.
2. Place the cardiac tissue sample (procured by the tissue bank or surgical team) in storage medium composed of chilled Dulbecco's modified Eagle medium (DMEM) containing 20% fetal bovine serum (FBS) and 1% penicillin-streptomycin (P/S) on ice for transportation³.
3. Remove the cardiac sample from the storage medium and wash with a washing medium composed of phosphate-buffered saline (PBS) supplemented with 2% FBS and 1% P/S. When handling the sample, use fine tipped forceps to grasp large vesse....

Results

Single cells were distinguished from debris and doublets on the basis of forward and side scatter distributions. Live cells were identified by their failure to take up the DAPI dye. The gating strategy was chosen on the basis of isotype control labelling of this live, whole-cardiac cell dissociation (Figure 1). From the live cells, CD45⁺ cells were first gated out, followed by CD56⁺ cells. CD144⁺ endothelial cells were then removed from th.......

Discussion

Increasing evidence supports a limited regenerative capacity of the adult human heart after injury. Identification and characterization of native precursor cells responsible for such regenerative responses in injured hearts are critical for both the understanding of associated mechanisms and signalling pathways and the development of approaches to utilize these cells therapeutically.

Previous protocols have described the isolation of perivascular precursor cell subsets from human skeletal musc.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
AbC Anti-mouse Bead Kit	Molecular Probes	A-10344
Collagenase I	Gibco	17100-017	Reconstitute powder as required and filter sterilise
Collagenase II	Gibco	17101-015
Collagenase IV	Gibco	17104-019
anti-human CD34-PE	BD Pharmingen	555822	Keep sterile
anti-human CD45-APC-Cy7	BD Pharmingen	557833	Keep sterile
anti-human CD56-PE-Cy7	BD Pharmingen	557747	Keep sterile
anti-human CD144-PerCP-Cy5.5	BD Pharmingen	561566	Keep sterile
anti-human CD146-AF647	AbD Serotec	MCA2141A647	Keep sterile
EGM2-BulletKit	Lonza	CC-3162	For collection of cells and culture until adhered
DMEM, high glucose, GlutaMAX without sodium pyruvate	ThermoFischer Scientific	10566-016
Fetal Bovine Serum	ThermoFischer Scientific	10500-064	Freeze in aliquots and keep sterile
Gelatin	Sigma Aldrich	G1393	Dilute with sterile water
IgG1k-PE	BD Pharmingen	559320	Keep sterile
IgG1k-APC-Cy7	BD Pharmingen	557873	Keep sterile
IgG1k-PE-Cy7	BD Pharmingen	557872	Keep sterile
IgG1k-PerCP-Cy5.5	BD Pharmingen	561566	Keep sterile
IgG1k-647	AbD Serotec	MCA1209A647	Keep sterile
Mouse serum	Sigma Aldrich	M5905	Keep sterile
Paraffin Film - Parafilm M	Sigma Aldrich	P7793
Penicillin-Streptomycin	Gibco	15979-063	Freeze in aliquots and keep sterile
Phosphate buffered saline pH 7.4	ThermoFischer Scientific	10010-023	Keep sterile
Red Blood Cell Lysing Buffer Hybri-Max	Sigma Aldrich	R7757	Keep sterile
Trypan Blue Solution	Sigma Aldrich	T8154
Trypsin-EDTA 0.5%(10x)	Invitrogen	15400-054
FACSARIA FUSION	BD Pharmingen		Fluorescence Activated Cell Sorter