Hypoxic/normoxic preconditioning increases endothelial differentiation potential of human bone marrow CD133+ cells

Area of Science:

• Stem cell biology
• Vascular biology
• Hematology

Background:

• CD133+ cells are hemangioblasts with potential to differentiate into hematopoietic and endothelial cells (ECs).
• Oxygen levels (hypoxia/normoxia) are known regulators of stem cell balance between self-renewal and differentiation.

Purpose of the Study:

• To investigate the effect of hypoxic/normoxic preconditioning on the differentiation potential of bone marrow-derived CD133+ cells.
• To analyze gene expression changes associated with differentiation.

Main Methods:

• Agilent's whole human genome oligo microarray analysis.
• Colony-forming unit assays (CFU-E, CFU-granulocyte, erythrocyte, monocyte, megakaryocyte, and CFU-EC).
• Reverse transcription-polymerase chain reaction and immunostaining.

Main Results:

• Hypoxic/normoxic preconditioning did not significantly increase hematopoietic progenitor formation (CFU-E).
• A significant increase in endothelial cell (EC) forming units was observed after 24h of hypoxic preconditioning.
• Differentiated cells lost hematopoietic stem cell markers and gained EC-specific gene markers and functional phenotypes.
• Transcriptome analysis revealed significant upregulation of angiogenic genes and downregulation of angiogenesis inhibitors.

Conclusions:

• Hypoxic/normoxic preconditioning promotes the differentiation of CD133+ cells towards the endothelial lineage.
• This differentiation strategy may offer benefits for clinical applications and studies involving endothelial cells.