VCAM-1 expression is upregulated by CD34+/CD133+-stem cells derived from septic patients

Area of Science:

• Immunology
• Vascular Biology
• Critical Care Medicine

Background:

• CD34+/CD133+ stem cells are crucial for vascular repair.
• Sepsis involves complex immune responses affecting vascular integrity.
• Adhesion molecules mediate stem cell homing to injured sites.

Purpose of the Study:

• To investigate the expression of adhesion molecules (ICAM-1, VCAM-1, E-selectin, L-selectin) on CD34+/CD133+ stem cells in septic patients.
• To determine if this expression correlates with sepsis severity and clinical outcomes.
• To explore the role of these molecules in stem cell homing during sepsis.

Main Methods:

• Isolation of peripheral blood mononuclear cells from ICU patients (sepsis and non-sepsis) and healthy volunteers.
• Flow cytometry to detect adhesion molecule expression on CD34+/CD133+ stem cells.
• Assessment of disease severity using SAPS II and measurement of VEGF and Ang-2 serum levels.

Main Results:

• Significantly upregulated expression of VCAM-1, ICAM-1, E-selectin, and L-selectin on CD34+/CD133+ stem cells in septic patients.
• Expression levels correlated positively with sepsis severity (SAPS II score).
• High VCAM-1 expression on these stem cells was associated with increased mortality.

Conclusions:

• VCAM-1 upregulation on CD34+/CD133+ stem cells is implicated in their homing during sepsis.
• Increased sepsis severity leads to higher numbers of CD34+/CD133+ stem cells and VCAM-1 expression, potentially indicating an increased need for vascular repair.