Human endometrial stem cells: High-yield isolation and characterization

Area of Science:

• Stem Cell Biology
• Regenerative Medicine
• Gynecology

Background:

• Menstrual blood is an understudied, abundant source of mesenchymal stromal cells (MSCs).
• Existing isolation methods are inadequate due to blood viscosity, clots, and epithelial debris.

Purpose of the Study:

• To develop and validate an effective method for isolating MSCs from menstrual blood.
• To characterize the isolated MSCs for their proliferative capacity, surface markers, and differentiation potential.

Main Methods:

• Investigated three isolation approaches: ammonium-containing lysing buffer, distilled water, and gradient-density centrifugation.
• Assessed cell proliferation, morphology, surface marker expression (CD90, CD105, CD73, CD45, CD34, CD117, CD133, HLA-G), and pluripotency.
• Evaluated early endometrial MSCs (eMSCs) for epithelial marker cytokeratin 7 (CK7) expression.

Main Results:

• Developed a cost-effective method yielding up to 4 million nucleated cells/mL, with 0.2-0.3% being MSCs.
• Isolated MSCs exhibited high proliferation (26h doubling time), standard mesenchymal markers, and adipogenic/osteogenic differentiation capacity.
• eMSCs expressed CK7, which is inducible in later passages, and consistent yields were obtained throughout the menstrual cycle.

Conclusions:

• The novel method provides a stable and adequate yield of homogenous, highly proliferative MSCs from menstrual blood.
• These MSCs are promising candidates for internal organ therapy due to their proepithelial characteristics and for mass cryobanking owing to their availability and yield.