Isolation and characterization of equine endometrial mesenchymal stromal cells

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.

The Healthy and Diseased Equine Endometrium: A Review of Morphological Features and Molecular Analyses

“…Intrauterine infusions of mares with autologous conditioned serum [101], allogenic bone marrow-derived mesenchymal stem cells (MSCs) [101], or autologous endometrial MSCs [102] revealed the anti-inflammatory properties of these treatments. This suggest their possible prophylactic or therapeutic use in mares susceptible to persistent endometritis [101,102]. Due to the lack of available therapies, currently equine endometrosis is regarded as an irreversible disease [3,8].…”

The use of mesenchymal stem cells in veterinary medicine

“…A recently published study revealed, for the first time, a successful attempt to obtain MSCs from the horse's uterus [27]. Researchers demonstrated the presence, in the endometrium, of cells that fit the definition of mesenchymal stem cells.…”

New Approaches to Dermatological Conditions Employing Mesenchymal Stem Cell Therapies

“…MSCs were originally isolated from the bone marrow [11], but later they have been obtained from nearly all tissues of the body, including adipose tissue [12,13], umbilical cord blood [14], umbilical cord Wharton's jelly [15,16], allanto-amniotic membranes [17], synovia [18], periost [13], skeletal muscle [13], teeth [19], placenta [20] or endometrium [21]. All of them were sources of MSCs, as determined by morphology, adherence to plastic, trilineage differentiation, and detection of stem cell surface markers with immunofluorescent and flow cytometric analyses.…”