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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, OBJECTIVE, RESULTS. Meshes: Animals, Antigens, CD, Atrophy, Behavior, Animal, Blood-Brain Barrier, Brain Edema, Capillary Permeability, Carcinoembryonic Antigen, Cell Adhesion Molecules, Disease Models, Animal, Flow Cytometry, Heterocyclic Compounds, 1-Ring, Humans, Infarction, Middle Cerebral Artery, Inflammation Mediators, Magnetic Resonance Imaging, Male, Matrix Metalloproteinase 9, Matrix Metalloproteinase Inhibitors, Mice, Mice, Inbred C57BL, Mice, Knockout, Microscopy, Fluorescence, Motor Activity, Neurologic Examination, Neutrophil Activation, Neutrophil Infiltration, Neutrophils, Sulfones, Time Factors.
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Does carcinoembryonic antigen-related cell adhesion molecule 1 inhibit MMP-9-mediated blood-brain-barrier breakdown in a mouse model for ischemic stroke? Context: Blood-brain-barrier (BBB) breakdown and cerebral edema result from postischemic inflammation and contribute to mortality and morbidity after ischemic stroke. A functional role for the carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in the regulation of reperfusion injury has not yet been demonstrated. We sought to identify and characterize the relevance of CEACAM1-expressing inflammatory cells in BBB breakdown and outcome after ischemic stroke in Ceacam1(-/-) and wild-type mice. Focal ischemia was induced by temporary occlusion of the middle cerebral artery with a microfilament. Using MRI and Evans blue permeability assays, we observed increased stroke volumes, BBB breakdown and edema formation, reduction of cerebral perfusion, and brain atrophy in Ceacam1(-/-) mice. This translated into poor performance in neurological scoring and high poststroke-associated mortality. Elevated neutrophil influx, hyperproduction, and release of neutrophil-related matrix metalloproteinase-9 in Ceacam1(-/-) mice were confirmed by immune fluorescence, flow cytometry, zymography, and stimulation of neutrophils. Importantly, neutralization of matrix metalloproteinase-9 activity in Ceacam1(-/-) mice was sufficient to alleviate stroke sizes and improve survival to the level of CEACAM1-competent animals. Immune histochemistry of murine and human poststroke autoptic brains congruently identified abundance of CEACAM1(+)matrix metalloproteinase-9(+) neutrophils in the ischemic hemispheres.
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CEACAM1 controls matrix metalloproteinase-9 secretion by neutrophils in postischemic inflammation at the BBB after stroke. We propose CEACAM1 as an important inhibitory regulator of neutrophil-mediated tissue damage and BBB breakdown in focal cerebral ischemia. Final Decision: yes