Quantitative Proteomic Analysis of Membrane Proteins Involved in Astroglial Differentiation of Neural Stem Cells by SILAC Labeling Coupled with LC–MS/MS

Membrane proteins play a critical role in the process
of neural
stem cell self-renewal and differentiation. Here, we apply the SILAC
(stable isotope labeling by amino acids in cell culture) approach
to quantitatively compare the membrane proteome of the self-renewing
and the astroglial differentiating cells. High-resolution analysis
on a linear ion trap-Orbitrap instrument (LTQ-Orbitrap) at sub-ppm
mass accuracy resulted in confident identification and quantitation
of more than 700 distinct membrane proteins during the astroglial
differentiation. Of the 735 quantified proteins, seven cell surface
proteins display significantly higher expression levels in the undifferentiated
state membrane compared to astroglial differentiating membrane. One
cell surface protein transferrin receptor protein 1 may serve as a
new candidate for NSCs surface markers. Functional clustering of differentially
expressed proteins by Ingenuity Pathway Analysis revealed that most
of overexpressed membrane proteins in the astroglial differentiation
neural stem cells are involved in cellular growth, nervous system
development, and energy metabolic pathway. Taken together, this study
increases our understanding of the underlying mechanisms that modulate
complex biological processes of neural stem cell proliferation and
differentiation.