eCite Digital Repository

Oral administration of a GSK3 inhibitor increases brain insulin-like growth factor I levels


Bolos, M and Fernandez, S and Torres-Aleman, I, Oral administration of a GSK3 inhibitor increases brain insulin-like growth factor I levels, Journal of Biological Chemistry, 285, (23) pp. 17693-17700. ISSN 0021-9258 (2010) [Refereed Article]

DOI: doi:10.1074/jbc.M109.096594


Reduced brain input of serum insulin-like growth factor I (IGF-I), a potent neurotrophic peptide, may be associated with neurodegenerative processes. Thus, analysis of the mechanisms involved in passage of blood-borne IGF-I into the brain may shed light onto pathological mechanisms in neurodegeneration and provide new drug targets. A site of entrance of serum IGF-I into the brain is the choroid plexus. The transport mechanism for IGF-I in this specialized epithelium involves the IGF-I receptor and the membrane multicargo transporter megalin/LRP2. We have now analyzed this process in greater detail and found that the IGF-I receptor interacts with the transmembrane region of megalin, whereas the perimembrane domain of megalin is required for IGF-I internalization. Furthermore, a GSK3 site within the Src homology 3 domain of the C-terminal region of megalin is a key regulator of IGF-I transport. Thus, inhibition of GSK3 markedly increased internalization of IGF-I, whereas mutation of this GSK3 site abrogated this increase. Notably, oral administration of a GSK3 inhibitor to adult wild-type mice or to amyloid precursor protein/presenilin 1 mice modeling Alzheimer amyloidosis significantly increased brain IGF-I content. These results indicate that pharmacological modulation of IGF-I transport by megalin may be used to increase brain availability of serum IGF-I. Interestingly, GSK3 inhibitors such as those under development to treat Alzheimer disease may show therapeutic efficacy in part by increasing brain IGF-I levels, an effect already reported for other neuroprotective compounds.

Item Details

Item Type:Refereed Article
Research Division:Biomedical and Clinical Sciences
Research Group:Neurosciences
Research Field:Cellular nervous system
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the biological sciences
UTAS Author:Bolos, M (Dr Marta Bolos Jurado)
ID Code:87500
Year Published:2010
Web of Science® Times Cited:29
Deposited By:Menzies Institute for Medical Research
Deposited On:2013-11-20
Last Modified:2013-11-20

Repository Staff Only: item control page