Albumin stimulates monocyte chemotactic protein-1 expression in rat embryonic mixed brain cells

• Published in: Journal of neuroscience research 2005-06, Vol.80 (5), p.707-714
• Main Authors: Calvo, Charles-Félix, Amigou, Edwige, Tencé, Martine, Yoshimura, Teizo, Glowinski, Jacques
• Format: Article
• Language: English
• Subjects: agonist; albumins; Animals; Astrocytes - cytology; Astrocytes - drug effects; Astrocytes - physiology; brain; Brain - cytology; Brain - embryology; Cells, Cultured; Chemokine CCL2 - genetics; Chemokine CCL2 - metabolism; Coculture Techniques; cytology; Gene Expression - drug effects; Macrophages - cytology; Macrophages - drug effects; Macrophages - physiology; monocyte chemoattractant protein-1; Neurons - cytology; Neurons - drug effects; Neurons - physiology; Ovalbumin - pharmacology; pharmacology; Rats; Rats, Inbred Strains; Serum Albumin, Bovine - pharmacology
• ISSN: 0360-4012; 1097-4547
• DOI: 10.1002/jnr.20511

Albumin, a blood protein absent from the adult brain in physiological situations, can be brought into contact with brain cells during development or, in adult, following breakdown of the blood–brain barrier occurring as a result of local inflammation. In the present study, we show that ovalbumin and albumin induce the release of monocyte chemotactic protein 1 (MCP‐1/CCL2) from rat embryonic mixed brain cells. A short‐term exposure to ovalbumin during the cell dissociation procedure is sufficient to generate MCP‐1 mRNA. A comparable effect is observed when the cells are incubated for 4 hr with ovalbumin or rat albumin, while MCP‐1 messengers are barely detectable following bovine albumin exposure. The amount of MCP‐1 protein measured in 4 hr‐supernatants of albumin‐treated cells followed the same albumin‐inducing pattern as that of MCP‐1 mRNA, while all albumins tested induced MCP‐1 protein after a 17 hr‐incubation period. The albumin‐induced MCP‐1 production is significantly inhibited in calphostin C‐treated cells, suggesting the implication of a protein kinase C‐dependent signaling pathway. This MCP‐1‐inducing activity is maintained after a lipid extraction procedure but abolished by proteinase K or trypsin treatments of albumin. The MCP‐1 secretion following albumin contact with nervous cells could thus interfere, by chemotactic gradient formation, with the brain infiltration program of blood‐derived cells during development or brain injury. © 2005 Wiley‐Liss, Inc.