Bio-released gold ions modulate expression of neuroprotective and hematopoietic factors after brain injury

The discovery of neural stem cells (NSCs) provides new therapeutic strategies for brain injury by means of endogenous cell renewal. In the injured mouse brain, bio-liberated gold ions from gold implants mediate anti-inflammatory and antiapoptotic effects and activation of NSCs. This paper investigates the neuroprotective effects of gold following brain injury in mice. We show for the first time that endogenous NSCs express macrophage colony-stimulating factor (M-CSF) as part of their post-injury activation and that gold implants increase this response. Also, gold increases expression of neurotrophin (NT)-4, transforming growth factor-beta 3 (TGF-β3), leukemia inhibitory factor (LIF) and metallothionein I + II (MT-I + II) post-injury. This paper shows that gold ions modulate neurotrophic factors after injury and that hematopoietic factor M-CSF is expressed in activated NSCs.