Isolation and characterization of equine endometrial mesenchymal stromal cells

B Elisabeth Rink,Cristina L Esteves,Karin R Amilon,Elaine Watson,F Xavier Donadeu,Hilari M French,Christine Aurich

doi:10.1186/s13287-017-0616-0

Abstract

BackgroundEquine mesenchymal stromal/stem cells (MSCs) are most commonly harvested from bone marrow (BM) or adipose tissue, requiring the use of surgical procedures. By contrast, the uterus can be accessed nonsurgically, and may provide a more readily available cell source. While human endometrium is known to harbor mesenchymal precursor cells, MSCs have not been identified in equine endometrium. This study reports the isolation, culture, and characterization of MSCs from equine endometrium.MethodsThe presence of MSC and pericyte markers in endometrial sections was determined using immunohistochemistry. Stromal cells were harvested and cultured after separation of epithelial cells from endometrial fragments using Mucin-1-bound beads. For comparison, MSCs were also harvested from BM. The expression of surface markers in endometrial and BM-derived MSCs was characterized using flow cytometry and quantitative polymerase chain reaction. MSCs were differentiated in vitro into adipogenic, chondrogenic, osteogenic, and smooth muscle lineages.ResultsTypical markers of MSCs (CD29, CD44, CD90, and CD105) and pericytes (NG2 and CD146) were localized in the equine endometrium. Both endometrial and BM MSCs grew clonally and robustly expressed MSC and pericyte markers in culture while showing greatly reduced or negligible expression of hematopoietic markers (CD45, CD34) and MHC-II. Additionally, both endometrial and BM MSCs differentiated into adipogenic, osteogenic, and chondrogenic lineages in vitro, and endometrial MSCs had a distinct ability to undergo smooth muscle differentiation.ConclusionsWe have demonstrated for the first time the presence of cells in equine endometrium that fulfill the definition of MSCs. The equine endometrium may provide an alternative, easily accessible source of MSCs, not only for therapeutic regeneration of the uterus, but also for other tissues where MSCs from other sources are currently being used therapeutically.

Highlights

Equine mesenchymal stromal/stem cells (MSCs) are most commonly harvested from bone marrow (BM) or adipose tissue, requiring the use of surgical procedures
Minimum criteria defining human MSCs were established by the International Society for Cellular Therapy in 2006 [3] and include: plastic adherence under standard culture conditions; expression of the surface markers CD73, CD90, and CD105 and lack of expression of hematopoietic markers as well as HLA-DR; and ability to undergo adipogenic, chondrogenic, and osteogenic differentiation in vitro
Localization of MSC and perivascular markers in equine endometrium Endometrial tissue was analyzed for the presence of a selection of cluster of differentiation (CD) antigens commonly used to identify human MSCs, namely CD29, CD44, CD90, and CD105 (Fig. 1a), as well as the perivascular cell surface markers, CD146 and NG2 (Fig. 1b)

Summary

Introduction

Equine mesenchymal stromal/stem cells (MSCs) are most commonly harvested from bone marrow (BM) or adipose tissue, requiring the use of surgical procedures. Studies in vitro and using cell transplantation in model species have shown that, in addition to providing different types of precursor cells, MSCs contribute to tissue repair through immunomodulatory, antiapoptotic, antimicrobial, and a variety of other trophic effects that act to enhance endogenous repair mechanisms [8]. Based on these findings, several hundred clinical trials are currently being carried out using human MSCs [9]

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