An FTIR Microspectroscopy Ratiometric Approach for Monitoring X-ray Irradiation Effects on SH-SY5Y Human Neuroblastoma Cells

Abstract

The ability of Fourier transform infrared (FTIR) spectroscopy in analyzing cells at a molecular level was exploited for investigating the biochemical changes induced in protein, nucleic acid, lipid, and carbohydrate content of cells after irradiation by graded X-ray doses. Infrared spectra from in vitro SH-SY5Y neuroblastoma cells following exposure to X-rays (0, 2, 4, 6, 8, 10 Gy) were analyzed using a ratiometric approach by evaluating the ratios between the absorbance of significant peaks. The spectroscopic investigation was performed on cells fixed immediately (t0 cells) and 24 h (t24 cells) after irradiation to study both the initial radiation-induced damage and the effect of the ensuing cellular repair processes. The analysis of infrared spectra allowed us to detect changes in proteins, lipids, and nucleic acids attributable to X-ray exposure. The ratiometric analysis was able to quantify changes for the protein, lipid, and DNA components and to suggest the occurrence of apoptosis processes. The ratiometric study of Amide I band indicated also that the secondary structure of proteins was significantly modified. The comparison between the results from t0 and t24 cells indicated the occurrence of cellular recovery processes. The adopted approach can provide a very direct way to monitor changes for specific cellular components and can represent a valuable tool for developing innovative strategies to monitor cancer radiotherapy outcome.

Radiation-Induced Effect on Spin-Selective Electron Transfer through Self-Assembled Monolayers of ds-DNA

“…This shift in the peak position indicates that there is a change in the mode of vibrations due to the change in structure (local stress) because of the formation of intermediate complexes after irradiation. Any change in the structure/damage in DNA is reflected in the change in peak positions or intensity in FT-IR spectra and has been verified experimentally as reported in the literature previously [38][39][40][41][42]. Very recently, it has been demonstrated theoretically that vibration enhances the electronic coherent effect, and spin-dependent electron-phonon coupling brings more tunneling paths in the ds-DNA molecules promoting CISS-induced polarization [43][44][45][46][47].…”

FT-IR Transflection Micro-Spectroscopy Study on Normal Human Breast Cells after Exposure to a Proton Beam

“…The latter wavenumber shifts point to changes in DNA conformation [40,46]. In Table 2, the assignments for all the resolved peaks are shown [2,[4][5][6]35,44]. In addition, the analysis of second derivative spectra (data not shown) of control cells allowed the identification of other contributions.…”

“…The analysis of the different peaks constituting the Amide I band can give accurate information on the secondary structure of proteins and their conformational changes due to different doses of ionizing radiation [6,[36][37][38]. The Amide I band (Figure 2C) can be considered as a convolution of the contributions due to the various secondary structures of proteins; the bands between 1620-1640 cm −1 and ≈1690 cm −1 can likely be attributed to β-sheet structures with the ≈1620 and 1690 cm −1 band characteristic of the anti-parallel β-sheet structures.…”

“…Recently, some of us reported a µ-FT-IR investigation on neuroblastoma cells (SH-SY5Y cell line), in which the use of ratios between absorbances of appropriately chosen peaks was adopted for studying X-ray irradiation effects [6]. This approach represents a very direct way to monitor changes for specific cellular components.…”

Evaluation by MALDI-TOF MS and PCA of the diversity of biosurfactants and their producing bacteria, as adaption to weathered oil components

“…The strong absorption peak at 3270 cm −1 corresponds to the stretching vibrations of –NH and –OH groups related to peptides [49] . The absorption peaks in the range from 2960 cm −1 and 2860 cm −1 are due to the asymmetric and symmetric stretching of the methylene groups of lipids (–CH 2 ) [ 50 , 51 ]. The absorption peak at 1640 cm −1 - 1630 cm −1 can be attributed to the CO-NH bend (due to the stretching vibrations of C=O and C-N groups), which confirms the presence of a peptide group in the biosurfactants [52] .…”