Stromal hemopoietic microenvironment in aging

Area of Science:

• Gerontology
• Hematology
• Stem Cell Biology

Background:

• Bone marrow microenvironment is crucial for hematopoiesis.
• Age-related changes in bone marrow can impact stem cell function.
• Stromal fibroblast colony-forming cells (CFC-F) are key components of the bone marrow niche.

Purpose of the Study:

• To investigate age-related changes in bone marrow CFC-F.
• To compare the proliferative potential and activity of CFC-F in young and old mice.
• To examine the relationship between CFC-F and other bone marrow cell populations.

Main Methods:

• CBA mice of young and old age groups were used.
• Bone marrow cellularity, CFC-F content, and proliferative potential were assessed.
• Proliferative activity was evaluated by hydroxyurea sensitivity of CFC-F and spleen colony-forming cells (CFC-S).
• Correlations between CFC-F, nucleated cells, and granulocytic-macrophagal colony-forming cells (GM-CFC) were analyzed.

Main Results:

• Old mice exhibited increased CFC-F content compared to young mice.
• No significant difference in the proliferative potential of CFC-F was observed between age groups.
• Both young and old mice showed similar hydroxyurea sensitivity for CFC-F and CFC-S, indicating comparable proliferative activity.
• A direct correlation between CFC-F and nucleated cells/GM-CFC was found in young mice, but this correlation was absent in old mice.

Conclusions:

• Aging leads to an increase in bone marrow CFC-F but does not alter their proliferative capacity.
• The relationship between stromal cells and hematopoietic precursors is disrupted in aged bone marrow.
• These findings suggest a reorganization of the bone marrow stromal microenvironment with advancing age.