RAGE mediates vascular injury and inflammation after global cerebral ischemia

Area of Science:

• Neuroscience
• Pathology
• Molecular Biology

Background:

• The receptor for advanced glycation end products (RAGE) is implicated in various pathological conditions.
• Its role in global cerebral ischemia, a critical neurological event, remains incompletely understood.
• Endogenous secretory RAGE (esRAGE) acts as a decoy receptor, potentially modulating RAGE signaling.

Purpose of the Study:

• To investigate the roles of RAGE and esRAGE in the context of global cerebral ischemia.
• To elucidate the impact of RAGE and esRAGE on neuronal survival, vascular changes, and neuroinflammation following ischemic injury.

Main Methods:

• Utilized three mouse cohorts: wild-type, RAGE knockout (RAGE⁻/⁻), and esRAGE transgenic (Tg) mice.
• Induced global cerebral ischemia using bilateral common carotid artery occlusion (BCCAO).
• Assessed RAGE expression via RT-PCR and immunohistochemistry; quantified neuronal survival, 3-nitrotyrosine (3-NT), endothelial nitric oxide synthase (eNOS), and inflammatory mediators (TNFα, iNOS).

Main Results:

• RAGE expression was upregulated in hippocampal vascular cells, neurons, and glia post-BCCAO.
• RAGE⁻/⁻ and esRAGE Tg mice exhibited significantly higher neuronal survival in the CA1 region compared to wild-type mice.
• Reduced 3-NT and increased eNOS with enlarged vascular areas were observed in RAGE⁻/⁻ and esRAGE Tg mice early post-ischemia.
• Later, RAGE⁻/⁻ and esRAGE Tg mice showed decreased expression of inflammatory mediators TNFα and iNOS.

Conclusions:

• RAGE signaling contributes to delayed neuronal death following global cerebral ischemia.
• RAGE activation exacerbates ischemic injury by promoting vascular damage and glia-mediated inflammation.
• Targeting RAGE or enhancing esRAGE may represent a therapeutic strategy for mitigating ischemic brain damage.