Effects of amyloid β-peptides and gangliosides on mouse neural stem cells.

The interaction of amyloid β-proteins (Aβs) with membrane lipids has been postulated as an early event in Aβ fibril formation in Alzheimer's disease. We evaluated the effects of several putative bioactive Aβs and gangliosides on neural stem cells (NSCs) isolated from embryonic mouse brains or the subventricular zone of adult mouse brains. Incubation of the isolated NSCs with soluble Aβ1-40 alone did not cause any change in the number of NSCs, but soluble Aβ1-42 increased their number. Aggregated Aβ1-40 and Aβ1-42 increased the number of NSCs but soluble and aggregated Aβ25-35 decreased the number. Soluble Aβ1-40 and Aβ1-42 did not affect the number of apoptotic cells but aggregated Aβ1-40 and Aβ1-42 did. When NSCs were treated with a combination of GM1 or GD3 and soluble Aβ1-42, cell proliferation was enhanced, indicating that both GM1 and GD3 as well as Aβs are involved in promoting cell proliferation and survival of NSCs. These observations suggest the potential of beneficial effects of using gangliosides and Aβs for promoting NSC proliferation.