Isolation and Characterization of an Adult Stem Cell Population from Human Epidural Fat.

Nedaa Al-Jezani,Roger Cho,Anand O Masson,Frank G Lyons,Brian Lenehan,Roman Krawetz

doi:10.1155/2019/2175273

Abstract

Study Design Isolation and characterization of human epidural fat (HEF) stem/progenitor cells. Objective To identify a progenitor population within HEF and to determine if they meet the minimal criteria of a mesenchymal stem cell (MSC). Summary of Background Data The biological function, if any, has yet to be determined for HEF. The presence of MSCs within HEF may indicate a regenerative potential within the HEF. Methods HEF was isolated from 10 patients during elective spinal surgery. HEF cells were differentiated along osteo-, adipo-, and chondrogenic lineages, with differentiation analyzed via qPCR and histology. The cell surface receptor profile of HEF cells was examined by flow cytometry. HEF cells were also assayed through the collagen contraction assay. Prx1CreERT2GFP:R26RTdTomato MSC lineage-tracking mice were employed to identify EF MSCs in vivo. Results HEF cell lines were obtained from all 10 patients in the study. Cells from 2/10 patients demonstrated full MSC potential, while cells from 6/10 patients demonstrated progenitor potential; 2/10 patients presented with cells that retained only adipogenic potential. HEF cells demonstrated MSC surface marker expression. All patient cell lines contracted collagen gels. A Prx1-positive population in mouse epidural fat that appeared to contribute to the dura of the spinal cord was observed in vivo. Conclusions MSC and progenitor populations are present within HEF. MSCs were not identified in all patients examined in the current study. Furthermore, all patient lines demonstrated collagen contraction capacity, suggesting either a contaminating activated fibroblast population or HEF MSCs/progenitors also demonstrating a fibroblast-like phenotype. In vivo analysis suggests that these cell populations may contribute to the dura. Overall, these results suggest that cells within epidural fat may play a biological role within the local environment above providing a mechanical buffer.

Highlights

Mesenchymal stem cells (MSCs) are well known for their self-renewal capacity and ability to differentiate into multiple cell lineages [1]
For a positive differentiation result into a specific lineage, a positive result for both Quantitative PCR (qPCR) and histology outcomes had to be obtained for a given cell line
The key finding of the current study is that cells isolated from human epidural fat (HEF) are metabolically active and have the ability to differentiate into osteo, chondro, and adipogenic lineages

Summary

Introduction

Mesenchymal stem cells (MSCs) are well known for their self-renewal capacity and ability to differentiate into multiple cell lineages [1]. Rather than being biologically redundant or a supposed mechanical buffer, the fat pad may promote some level of tissue maintenance and repair in the synovial environment but, at the least, contains cells that have regenerative potential in vitro [30, 36] These and other cellular studies on fat sites within the body serve as a rationale to investigate the biological characteristics of HEF and to examine it as a potential source of MSC and/or progenitor cell populations. If it is, this may force a reexamination of our current thinking of epidural fat, and whether or not we should continue to debride and discard it routinely

Materials and Methods

Results

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Discussion