sRAGE induces human monocyte survival and differentiation

Area of Science:

• Immunology
• Cell Biology

Background:

• The receptor for advanced glycation end products (RAGE) has known roles in disease.
• Soluble RAGE (sRAGE) is thought to inhibit membrane RAGE, but its inflammatory role is debated.

Purpose of the Study:

• To define the biological function of sRAGE in inflammatory cell recruitment, survival, and differentiation.
• To investigate the in vivo and in vitro effects of sRAGE.

Main Methods:

• Intratracheal administration of recombinant sRAGE to mice.
• In vitro migration assays using human monocytes and neutrophils.
• Analysis of cytokine production, cell binding, differentiation, and intracellular signaling pathways (Akt, Erk, NF-kappaB).

Main Results:

• Intratracheal sRAGE induced lung inflammation mediated by monocytes and neutrophils in mice.
• sRAGE stimulated monocyte and neutrophil migration and pro-inflammatory cytokine production in vitro.
• sRAGE directly bound monocytes and macrophages, promoting their survival and differentiation via Akt, Erk, and NF-kappaB activation.

Conclusions:

• sRAGE acts as a pro-inflammatory mediator, contrary to its proposed inhibitory role.
• sRAGE promotes monocyte and neutrophil recruitment and survival, contributing to inflammation.
• sRAGE plays a novel role in mononuclear phagocyte survival and differentiation.