IJPPP Copyright © 2009-All rights reserved. Published by e-Century Publishing Corporation, Madison, WI 53711
Int J Physiol Pathophysiol Pharmacol 2013;5(1):11-20

Original Article
Inhibition of the Rho signaling pathway improves neurite outgrowth and neuronal
differentiation of mouse neural stem cells

Haigang Gu, Shan Ping Yu, Claire-Anne Gutekunst, Robert E Gross, Ling Wei

Department of Anesthesiology and Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA 30322, USA; Coulter
De-partment of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA

Received December 13, 2012; Accepted December 26, 2012; Epub March 8, 2013; Published March 18, 2013

Abstract: Neurons in the adult mammalian CNS do not spontaneously regenerate axons after injury due to CNS myelin and other
inhibitory factors. Previous studies have showed that inhibition of the Rho-ROCK pathway promotes axonal outgrowth in primary
neurons or in spinal cord injury models. Furthermore, RhoA inhibitor C3 transferase has a potential effect to induce neural
differentiation in primary cultured neurons and cell lines. As stem cells and stem cell-derived neural progenitor cells have emerged as
a regenerative medicine for stroke, Parkinson’s disease and other neurological disorders, strategies that can promote axonal
outgrowth and neuronal differentiation appear to have promising benefits in the cell-based therapy. Currently, how changes in the Rho-
ROCK pathway may affect the neurite outgrowth and neuronal differentiation of stem cells has been poorly understood. The present
investigation examined the effects of RhoA inhibition on neurite outgrowth and neuronal differentiation of neural stem cells (NSCs)
isolated from the subventricular zone (SVZ) of the mouse. Our results show that inhibition of RhoA leads to neurite outgrowth of NSCs
not only on normal culture substrate, poly-D-lysine (PDL), but also on myelin substrate. Moreover, inhibition of RhoA improves neuronal
differentiation of NSCs and up-regulates biomarkers of neuronal gene expression. These results support that the Rho signaling
pathway plays an important role in neurite development and neuronal differentiation of NSCs. (IJPPP1212002)

Keywords: Neural stem cells, Rho signaling pathway, neurite outgrowth, neuronal differentiation, myelin

Address correspondence to: Dr. Ling Wei, Department of Anesthesiology; Dr. Robert E. Gross, Department of Neurosurgery, Emory
University School of Medicine, 101 Woodruff Circle, Suite 617, Atlanta, GA 30322, USA. Phone: +1 404 7278661 (LW); E-mail:
lwei7@emory.edu (LW); rgross@emory.edu (RG)