Human Endometrial Side Population Cells Exhibit Genotypic, Phenotypic and Functional Features of Somatic Stem Cells

Abstract

During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis for women's cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC) population. Here we explore the hypothesis that human endometrial side population (SP) cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and characteristic telomerase pattern. We analyzed the clonogenic activity of SP cells under hypoxic conditions and the differentiation capacity in vitro to adipogenic and osteogenic lineages. Finally, we demonstrated the functional capability of endometrial SP to develop human endometrium after subcutaneous injection in NOD-SCID mice. Briefly, SP cells of human endometrium from epithelial and stromal compartments display genotypic, phenotypic and functional features of SSC.

The role of stem cells in the pathogenesis of endometriosis (а review)

“…Это свидетельствовало о том, что в эндометрии чело-века присутствовали два разных типа стволовых кле-ток, которые различались по ростовым свойствам. Впоследствии на модельных животных было показа-но, что только стромальные стволовые клетки in vivo образовывали структуру, гистологически сходную с эндометриальными железами и стромой [33], т.е. именно они участвовали в регенерации эндометрия в менструальном цикле.…”

“…Доказательством существования стволовых кле-ток в эндометрии человека явились исследования по ксенотрансплантации in vivo, которые заключались в пересадке клеток функционального слоя эндоме-трия в организм иммунодефицитных мышей [33,34]. Полученные клетки демонстрировали свойства ство-ловых, в том числе пролиферативный потенциал и способность к дифференцировке в тканеспецифиче-ские типы зрелых клеток.…”

Regeneration capacity of the endometrium: endometrial stem cells

“…Yapılan çalımalarda endometrial mezenkimal kök hücrelerin in vitro olarak kondrosit, [20] adiposit [21] ve hematopoetik [22] farklılama gösterebil-dikleri saptanmıtır. Yapılan bir baka çalımada endometrial mezenkimal kök hücrelerin insülin ve glukagon sekrete eden endodermal pankreatik hücrelere farklılabildikleri ve bu hücrelerin immün sistemi baskılanmı farelerde oluturulan diyabet modelinde kan ekerini düürdükleri tespit edilmitir.…”

Endometrial Cancer Stem Cells: Are They a Possible Therapeutic Target?

“…Histological analyses of the transplantation sites revealed the presence of vascular components other than glandular and stromal components that were composed of CD31 + cells surrounded by α-smooth muscle actin (α-SMA) + cells, suggesting that SP cells have the potential to differentiate into vessels. Cervello et al implanted SP or non-SP cells into NOD-SCID mice and found that these cells from the epithelium do not give rise to any structures [14]. In contrast, SP cells from stromal fractions form macroscopic structures in the subcutaneous fat at the injection site.…”