title: Oleic acid synthesized in the periventricular zone promotes axonogenesis in the striatum during brain development.
abstract: Our previous works showed that oleic acid synthesized in vitro by astrocytes in response to albumin behaves as a neurotrophic factor in neurons, up-regulating several proteins, such as the axonal growth marker growth-associated protein 43(GAP-43). Although the molecular mechanism of this process is fairly known, there is no evidence pinpointing the region/s in which oleic acid is synthesized. In this study, we show that the rate-limiting enzyme in oleic acid synthesis, stearoyl-CoA desaturase (SCD-1), is located in the periventricular zone of the brain of newborn rats, simultaneously to an increase in the amount of free oleic acid in the forebrain. In addition, the spatio-temporal presence of albumin - the signal that promotes oleic acid synthesis - and that of GAP-43 are correlated with that of SCD-1. Using organotypic slice cultures, we found that albumin up-regulates SCD-1 and stimulates the growth of GAP-43-positive axons in the striatum. The effect of albumin on GAP-43 was reduced when SCD-1 was silenced by siRNA. In conclusion, our results suggest that albumin up-regulates axonogenesis in the striatum by increasing the amount of the neurotrophic factor oleic acid synthesized by SCD-1 in the periventricular zone of the newborn brain.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Instituto de Neurociencias de Castilla y León, INCYL, Universidad de Salamanca, Salamanca, Spain.
authors.forename: Erica
authors.initials: E
authors.lastname: Polo-Hernández
authors.forename: Fernando
authors.initials: F
authors.lastname: De Castro
authors.forename: Alejandro G
authors.initials: AG
authors.lastname: García-García
authors.forename: Arantxa
authors.initials: A
authors.lastname: Tabernero
authors.forename: José M
authors.initials: JM
authors.lastname: Medina
mesh_terms: D000418:Albumins / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000502:physiology*; D002552:Cerebral Ventricles / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D003342:Corpus Striatum / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D019922:GAP-43 Protein / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental; D019301:Oleic Acid / Q000096:biosynthesis*; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism; D046509:Tissue Culture Techniques
chemical_list: D000418:Albumins; D019922:GAP-43 Protein; D034741:RNA, Small Interfering; D019301:Oleic Acid; D013230:Stearoyl-CoA Desaturase