Fourier transform infrared microspectroscopy reveals unique phenotypes for human embryonic and induced pluripotent stem cell lines and their progeny

Abstract

Journal of BIOPHOTONICSFourier transform infrared (FTIR) microspectroscopy was employed to elucidate the macromolecular phenotype of human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) and their differentiated progeny. Undifferentiated hESCs and hiPSC lines were found to be not clearly distinguishable from each other. However, although both hESC and hiPSC variants appeared to undergo similar changes during differentiation in terms of cell surface antigens, the derived cell types from all cell lines could be discriminated using FTIR spectroscopy. We foresee a possible future role for FTIR microspectroscopy as a powerful and objective investigative and quality control tool in regenerative medicine.Bright field image of human embryonic stem cells in culture.

The Characterisation of Pluripotent and Multipotent Stem Cells Using Fourier Transform Infrared Microspectroscopy

“…In their first paper, the authors reported that spectra acquired from six ES lines and six unrelated iPSC cell lines were biochemically similar, as indicated by their spectral clusters co-localising in the scores plot, and further confirmed by the PLS-DA prediction modelling data [35]. This result is in agreement with findings from studies performed by our laboratory [36], in which we found marked biochemical differences within the same stem cell class, but no significant interclass spectral variation.…”

“…A key difference between the studies performed by Sandt and colleagues, and our laboratory is that the former does not address the consequences of differentiation on these spectral phenotypes [32,36]. We already knew that hESC undergoing differentiation towards ectodermal and mesendodermal lineages underwent lipid depletion and were therefore curious to see whether this was also the case with differentiated hIPSC lines, which indeed it was.…”

Morphological, molecular and FTIR spectroscopic analysis during the differentiation of kidney cells from pluripotent stem cells

“…Another band at 1454 cm −1 arises from the methyl and methylene groups from lipids and proteins, whereas the band at 1396 cm −1 is due to the COO − stretching vibrations of amino acid side chains [21]. The band at 1239 cm −1 is related to the P=O asymmetrical stretching of PO 2 phosphodiester groups from phosphorylated molecules, whereas the band at 1080 cm −1 arises from the P=O symmetrical stretching of PO 2 phosphodiester groups from phosphorylated molecules and glycogen [21, 23]. Other bands at 1154, 1055, and 1015 cm −1 respectively are related to C–O vibrations from glycogen and other carbohydrates [20].…”

“…Other bands at 1154, 1055, and 1015 cm −1 respectively are related to C–O vibrations from glycogen and other carbohydrates [20]. Finally, a band around 991 cm −1 is mainly due to C–O stretch from RNA ribose chain [17, 23].

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“…On the other hand, the second derivative spectra of the same samples in the region of the amide I group (1700–1600 cm −1 ) calculated with Savitzky-Golay algorithm allowed the identification of various secondary structures present in the proteins, as β-turns (1694 and 1680 cm −1 ), α-helices (1650 cm −1 ), and β-pleated sheets (1633 cm −1 ) [17, 21–23]; in the same way, differences between mPSCs and DKCs on three bands at 1675, 1670, and 1633 cm −1 were observed, which are also related to asparagine, glutamine, and arginine respectively (Fig. 6b) [22].…”