Interferon-gamma and interleukin-10 reciprocally regulate endothelial junction integrity and barrier function.

Area of Science:

• Gastroenterology
• Immunology
• Vascular Biology

Background:

• Inflammatory bowel disease (IBD) is linked to cytokine imbalances and vascular issues like edema.
• The precise mechanisms of cytokine-induced vascular dysfunction in IBD remain unclear.

Purpose of the Study:

• To investigate the role of cytokines, specifically interferon-gamma (IFN-γ) and interleukin-10 (IL-10), in controlling vascular permeability and edema in IBD.
• To examine the effects of IFN-γ and IL-10 on endothelial barrier function and tight junction proteins.

Main Methods:

• Assessed colonic microvascular leakage and IFN-γ levels in two murine colitis models (CD45RB(high)/SCID and IL-10(-/-) mice).
• Quantified vascular permeability using (131)I-IgG accumulation.
• Evaluated in vitro endothelial barrier integrity via transmonolayer electrical resistance and junctional protein expression (occludin) using immunoblotting and fluorescence microscopy.

Main Results:

• Both IBD models showed increased colonic microvascular leakage and elevated IFN-γ levels compared to controls.
• In vitro, IFN-γ impaired endothelial barrier function, decreasing electrical resistance and occludin expression.
• Interleukin-10 (IL-10) pretreatment reversed the detrimental effects of IFN-γ on endothelial cells.

Conclusions:

• Interferon-gamma (IFN-γ) contributes to increased microvascular leakage in inflammatory bowel disease (IBD).
• Interleukin-10 (IL-10) plays a protective role by maintaining endothelial barrier integrity.
• These cytokines modulate IBD-related microvascular leakage by influencing intestinal endothelial tight junction proteins.