Albumin stimulates monocyte chemotactic protein-1 expression in rat embryonic mixed brain cells.
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.
Calvo
Charles-Félix
CF
Chaire de Neuropharmacologie, INSERM U114, Collège de France, Paris, France. charles-felix.calvo@college-de-france.fr
Amigou
Edwige
E
Tencé
Martine
M
Yoshimura
Teizo
T
Glowinski
Jacques
J
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000166:cytology* / Q000196:embryology; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics* / Q000378:metabolism; D018920:Coculture Techniques; D015870:Gene Expression / Q000187:drug effects; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010047:Ovalbumin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012710:Serum Albumin, Bovine / Q000494:pharmacology*
D018932:Chemokine CCL2; D012710:Serum Albumin, Bovine; D010047:Ovalbumin