Fig. 9
FTIR analysis upon O-GlcNAc-mediated erythroid differentiation in K562 cells. FTIR spectra were recorded from more than 200 single cells in the mid-IR region of 4000 to 800 cm−1. A Two-dimensional PCA score plots of control (pLenti) (left) and OGAi (right) cells upon erythroid differentiation in the EPO-based medium at various times (day − 1 to day 10) showing distinct patterns. B, C (left) The second derivative spectra obtained from the mean FTIR spectra of pLenti and OGAi cells in the wavelength range of 3000–2800 cm−1 and 1750–800 cm−1. Band assignments for the region of lipid, ester (lipid), amide I, amide II, nucleic acid (DNA/RNA), and nucleic acid, glycoprotein, other carbohydrate (nucleic acid and others) on days 7 (B) and 10 (C) of differentiation were illustrated. (right) Integral area of total lipid, ester (lipid), amide I and amide II, and nucleic acid and others on days 7 (B) and 10 (C) were plotted. Data are mean ± SD (n = 3). *P < 0.05 versus pLenti cells on the same day of culture; two-sided Student's t test