Neural differentiation of mouse embryonic stem cells studied by FTIR spectroscopy

Embryonic Stem-derived Neural Cells (ESNCs) hold potential as a source of neurons for a cell-based therapy for the treatment of brain tumors, and other neurological diseases and disorders in the future. The sorting of neural cell types is envisaged to be one of the most important processed for clinical application of these cells in cell-based therapies of the central nervous system (CNS). In this study, laboratory-based FTIR and Synchrotron-FTIR (SR-FTIR) microspectroscopy were used to identify FTIR marker for distinguishing different neural cell types derived from the differentiation of mouse embryonic stem cells (mESCs). Principal Component Analysis (PCA) and Unsupervised Hierarchical Cluster Analysis (UHCA) were shown to be able to distinguish the developmental stage of mESCs into three cell types: embryoid bodies (EBs), neural progenitor cells (NPCs), and ESNCs. Moreover, PCA provided the mean for identifying potential FTIR “marker bands” that underwent dramatic changes during stem cell differentiation along neural lineages. These appeared to be associated with changes in lipids (bands from CH2 and CH3 stretching vibrations at ∼2959, 2923 and 2852 cm−1) and proteins (changes in the amide I band at ∼1659 and 1637 cm−1). The results suggested that lipid content of cells increased significantly over the time of differentiation, suggesting increased expression of glycerophospholipids. Changes in the amide I profile, suggested concomitant increases in α-helix rich proteins as mESCs differentiated towards ESNCs, with a corresponding decrease in β-sheet rich proteins, corresponding with changes in cytoskeleton protein which may have been taking place involved with the establishment of neural structure and function.