Cell-specific expression of insulin/insulin-like growth factor-I receptor hybrids in the mouse brain. (April 2019)

• Record Type: Journal Article
• Authors: Martinez-Rachadell, L.; Aguilera, A.; Perez-Domper, P.; Pignatelli, J.; Fernandez, A.M.; Torres-Aleman, I.
• Is Part Of: Growth hormone & IGF research. Volume 45(2019)
• Page Start: 25
• Page End: 30
• Publication Date: 2019-04
• Subjects: IGF-1 -- Insulin -- Brain -- Receptor hybrids; Growth regulators -- Periodicals; Growth -- Regulation -- Periodicals; Somatomedin -- Periodicals; Somatomedins -- Periodicals; Growth Hormone -- Periodicals; Growth Substances -- Periodicals; Croissance -- Régulation -- Périodiques; Croissance -- Régulateurs -- Périodiques; Somatotrophine -- Périodiques; Somatomédine -- Périodiques; Growth -- Regulation; Growth regulators; Electronic journals; Periodicals; Electronic journals; 612.4
• DOI: 10.1016/j.ghir.2019.02.003
• Languages: English
• ISSNs: 1096-6374

Abstract

Abstract: Insulin (IR) and insulin-like growth factor I (IGF-IR) receptors share structural homology and can form hybrid heterodimers. While different observations suggest that hybrid receptors are important in physiology and pathology, little is known about their function in the brain. To gain further insight into the role of IR/IGF-IR hybrids in this organ, we analyzed their cellular distribution in the mouse brain. We combined proximity ligation assays (PLA) for IR and IGF-IR, a technique that detects close protein-protein interactions, with immunocytochemistry for brain cell markers to identify IR/IGF-IR hybrids in the major types of brain cells. Intriguingly, while all the types of brain cells analyzed co-express both receptors, only neurons, astroglia, and microglia show readily detectable IR/IGF-IR hybrids. Hybrid PLA signal was negligible in brain endothelial cells and was absent in oligodendrocytes. Hybrids were comparatively more abundant in neurons and peaked after brain development was completed. Cell-specific expression and greater abundance in the adult brain suggests specialized actions of IR/IGF-IR hybrids in this organ, particularly in neurons. Highlights: All brain cells express insulin (IR) and IGF-I receptors (IGF-IR). Distribution of IR/IGF-IR hybrids varies greatly according to cell type. Relative abundance of hybrid IR/IGF-IR is highest in neurons Hybrids are relatively more abundant in the adult than in the young brain.