The ailing gut: a therapeutic role for bone marrow cells?

Area of Science:

• Gastroenterology
• Immunology
• Stem Cell Biology

Background:

• Bone marrow cells (BMCs) are known to supply the gastrointestinal tract (GIT) with immune cells.
• Emerging evidence suggests BMCs have broader roles beyond immune cell provision.

Purpose of the Study:

• To explore the multifaceted roles of BMCs in the GIT, including their potential differentiation, contribution to neovasculature, and involvement in epithelial turnover.
• To investigate the therapeutic potential of mesenchymal stem cells (MSCs), a type of BMC, in ameliorating colitis.

Main Methods:

• Review of existing studies on BMC differentiation and engraftment in various gastrointestinal injury models (rodents and humans).
• Examination of the role of cell fusion in BMC incorporation into the epithelial compartment.
• Analysis of clinical data regarding MSC therapy for colitis.

Main Results:

• BMCs can differentiate into intestinal stem and early mesenchymal progenitor cells (ISEMFs) and contribute to neovasculature formation during inflammation.
• BMC contribution to epithelial turnover is minimal after transient injury but observed with chronic injury, often via cell fusion.
• Engraftment in the stem cell compartment is rare, except in specific cases like chronic murine gastric infection.
• Mesenchymal stem cell (MSC) therapy shows promise for colitis, with immunomodulatory and regenerative effects likely mediating benefits.

Conclusions:

• BMCs possess significant differentiation and regenerative potential within the GIT.
• Further research is needed to fully elucidate the mechanisms of BMC action, particularly in chronic injury and colitis treatment.