Neurosci Lett. 2004 May 13;362(1):14-6
Chesik D, De Keyser J, Wilczak N.
Department of Neurology, University Hospital Groningen, Hanzeplein
1, 9713 GZ Groningen, The Netherlands.
In vitro studies suggest that insulin-like growth factor (IGF)-I is a mitogen for microglia/macrophages.
The actions of IGF-I are mediated by IGF-I receptors and modulated by IGF binding proteins (IGFBPs).
The aim of this study was to investigate IGF-I receptors and IGFBPs in human microglia in normal brain white matter and active lesions of multiple sclerosis, which contain activated microglia/macrophages.
Methods used were immunohistochemistry and confocal laser microscopy.
IGF-I receptors were demonstrated in both resting and activated microglia.
In resting conditions, microglia displayed no immunoreactivity for any of the six IGFBPs, whereas activated microglia/macrophages were immunoreactive for IGFBP-2 only.
Our data suggest an important function for IGFBP-2 in IGF-I actions in activated microglia/macrophages in human brain.