Peptide fragment of thymosin β4 increases hippocampal neurogenesis and facilitates spatial memory

•N-acetyl-serylaspartyl-lysyl-proline (Ac-SDKP), a peptide fragment of thymosin β4 facilitated hippocampal neurogenesis.•Ac-SDKP increase in β-catenin stability with reduction of glycogen synthase kinase-3β activity.•Moreover, inhibition of VEGF signaling blocked Ac-SDKP-facilitated neural proliferation.•Subchronic intrahippocampal infusion of Ac-SDKP also increased spatial memory.•Taken together, these data demonstrate that TB4 functions as a regulator of neurogenesis.

Although several studies have suggested the neuroprotective effect of thymosin β4 (TB4), a major actin-sequestering protein, on the central nervous system, little is understood regarding the action of N-acetyl-serylaspartyl-lysyl-proline (Ac-SDKP), a peptide fragment of TB4 on brain function. Here, we examined neurogenesis-stimulative effect of Ac-SDKP. Intrahippocampal infusion of Ac-SDKP facilitated the generation of new neurons in the hippocampus. Ac-SDKP-treated mouse hippocampus showed an increase in β-catenin stability with reduction of glycogen synthase kinase-3β (GSK-3β) activity. Moreover, inhibition of vascular endothelial growth factor (VEGF) signaling blocked Ac-SDKP-facilitated neural proliferation. Subchronic intrahippocampal infusion of Ac-SDKP also increased spatial memory. Taken together, these data demonstrate that Ac-SDKP functions as a regulator of neural proliferation and indicate that Ac-SDKP may be a therapeutic candidate for diseases characterized by neuronal loss.