Roles of Wnt/β-Catenin Signaling in Controlling the Dopaminergic Neuronal Cell Commitment of Midbrain and Therapeutic Application for Parkinson’s Disease

Parkinson’s disease (PD) is a severe deliberating neurodegenerative disease resulting from progressive and massive cell death of dopaminergic (DA) neurons in the substantia nigra [1]. While cell therapy strategy is strongly suggested for clinical cure of PD and DA progeni‐ tors are identified at different developing stages of midbrain, full understanding of key cell signaling or mechanism in controlling of DA neuronal differentiation from neural stem cells in vivo raises a great interest in cell therapeutic application for PD [2, 3]. A growing line of studies has shown that Wnts are lipid-modified factor for stem cell growth and cell differen‐ tiation and regulate midbrain DA neuronal development and hippocampal neurogenesis through both canonical and non-canonical Wnt signaling pathways [4-7]. The canonical Wnt/β-catenin signaling appeals a key mechanism in controlling DA neuronal fate decision from neural stem cells or progenitors in the ventral midbrain during embryonic develop‐ ment and adulthood [8]. This chapter has focused on fast growing knowledge on Wnt/β-cat‐ enin signaling pathway, intracellular cascade or crosstalk, functional roles in controlling DA neuronal fate decision and neural repair under physiological development and pathological events, and potential manipulation of Wnt/β-catenin signaling pathway as cell therapeutic target for treatment of PD in human beings.