FTIR spectroscopy of whole cells for the monitoring of yeast apoptosis mediated by p53 over-expression and its suppression by Nigella sativa extracts

Abstract

p53 over expression in yeast results in cell death with typical markers of apoptosis such as DNA fragmentation and phosphatidylserine externalization. We aimed to substitute/supplement classical fluorescent techniques (TUNEL, Annexin V, ROS detection) usually used to detect biochemical changes occurring during yeast apoptosis mediated by p53 over expression and the effect of anti-apoptotic purified molecules from Nigel (Nigella sativa) extracts on these same yeasts by the label free technique of FTIR spectroscopy. The comparison of the entire IR spectra highlighted clear modifications between apoptotic p53-expressing yeasts and normal ones. More precisely, DNA damage was detected by the decrease of band intensities at 1079 and 1048 cm-1. While phosphatidylserine exposure was followed by the increase of νsCH2 and νasCH2 bands of unsaturated fatty acids that were exhibited at 2855 and 2926 cm-1, and the appearance of the C = O ester functional group band at 1740 cm-1. In a second step, this FTIR approach was used to estimate the effect of a purified fraction of the Nigel extract. The modulation of band intensities specific to DNA and membrane status was in agreement with apoptosis supression in presence of the Nigel extracts. FTIR spectroscopy is thus proven to be a very reliable technique to monitor the apoptotic cell death in yeast and to be used as a means of evaluating the biomolecules effect on yeast survival.

From plants to feces: pilot applications of FTIR spectroscopy for studies on the foraging ecology of an avian herbivore

“…The spectral pattern of yeast was found to be comparable to literature (Berterame et al 2016;Tareb et al 2017). The bands at 3275 cm −1 and 1400 cm −1 can be assigned to the NH vibration of amines (Rozenberg and Shoham 2007) and to carboxylates in amino acids (Kumar et al 2014;Mihoubi et al 2017), respectively. The band at 1520 cm −1 represents the aromatic ring vibration of amino acids (Naumann et al 1996).…”

Study of the intracellular nanoparticle-based radiosensitization mechanisms in F98 glioma cells treated with charged particle therapy through synchrotron-based infrared microspectroscopy

“…8, AuNP-induced DNA damage is expressed by the decrease in the PhI and PhII bands, which might indicate DNA condensation. 28,29,46,53,56,57 A reduction on the absorbance of the phosphate I band was also reported upon oxidative stress. 48 The combination of all these spectral changes showed NPinduced DNA damage in different groups of the DNA molecule, which seems to correspond to the course of cell death processes.…”

“…• The CH 2 symmetric to CH 2 asymmetric stretching ratio (CH 2 stretching ratio) is another way to assess cell membrane morphology alterations. 29,64 In particular, a decrease in the CH 2 stretching ratio was associated to an increase in the membrane rigidity as a consequence of the presence of membrane stabilizing agents or lipid raft aggregates, which are formed in dying cells. 64 Fig.…”

“…The level of unsaturation of the fatty acids in the membrane has a high impact on the characteristics of the membrane. In particular, an increase of unsaturated fatty acids leads to alterations in the membrane fluidity, 29 which can highly affect functional properties of the cell. 65,66 • The distribution of the carbonyl ester group stretching band (1760-1730 cm −1 ) found in non-hydrogen bonded and hydrogen-bonded states in phospholipids was reported to be a good indicator of lipid peroxidation.…”

Infrared spectroscopy as a new tool for studying single living cells: Is there a niche?

“…Owing to the large number of spectral data collected in a single map, specific software based on multivariate statistical analysis have been developed to highlight spectral similarities and differences in a simple readout format [36,64]. Hence, subtle changes caused by various biochemical processes, such as the occurrence of specific pathologies, benign and malignant ones, or by various cellular differentiation steps, can be detected [27,29,30,40,61,63]. Cells are dynamic systems, changing their macromolecular composition during the cell cycle.…”