Over-expression of hNGF in Adult human Olfactory Bulb Neural Stem Cells promotes cell growth and oligodendrocytic differentiation.

The adult human olfactory bulb neural stem/progenitor cells (OBNC/PC) are promising candidate for cell-basedtherapy for traumatic and neurodegenerative insults. Exogenous application of NGF was suggested as a promisingtherapeutic strategy for traumatic and neurodegenerative diseases, however effective delivery of NGF into the CNSparenchyma is still challenging due mainly to its limited ability to cross the blood-brain barrier, and intolerable sideeffects if administered into the brain ventricular system. An effective method to ensure delivery of NGF into theparenchyma of CNS is the genetic modification of NSC to overexpress NGF gene. Overexpression of NGF in adulthuman OBNSC is expected to alter their proliferation and differentiation nature, and thus might enhance theirtherapeutic potential. In this study, we genetically modified adult human OBNS/PC to overexpress human NGF(hNGF) and green fluorescent protein (GFP) genes to provide insight about the effects of hNGF and GFP genesoverexpression in adult human OBNS/PC on their in vitro multipotentiality using DNA microarray,immunophenotyping, and Western blot (WB) protocols. Our analysis revealed that OBNS/PC-GFP and OBNS/PCGFP-hNGF differentiation is a multifaceted process involving changes in major biological processes as reflected inalteration of the gene expression levels of crucial markers such as cell cycle and survival markers, stemnessmarkers, and differentiation markers. The differentiation of both cell classes was also associated with modulations ofkey signaling pathways such MAPK signaling pathway, ErbB signaling pathway, and neuroactive ligand-receptorinteraction pathway for OBNS/PC-GFP, and axon guidance, calcium channel, voltage-dependent, gamma subunit 7for OBNS/PC-GFP-hNGF as revealed by GO and KEGG. Differentiated OBNS/PC-GFP-hNGF displayed extensivelybranched cytoplasmic processes, a significant faster growth rate and up modulated the expression of oligodendrogliaprecursor cells markers (PDGFR?, NG2 and CNPase) respect to OBNS/PC-GFP counterparts. These findingssuggest an enhanced proliferation and oligodendrocytic differentiation potential for OBNS/PC-GFP-hNGF ascompared to OBNS/PC-GFP.