Secondary structure alterations of RBC assessed by FTIR-ATR in correlation to 2,3-DPG levels in ApoE/LDLR–/– Mice

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2023-01, Vol.284, p.121819, Article 121819
• Main Authors: Alcicek, Fatih Celal, Blat, Aneta, Rutkowska, Wiktoria, Bulat, Katarzyna, Szczesny-Malysiak, Ewa, Franczyk-Zarow, Magdalena, Kostogrys, Renata, Dybas, Jakub, Marzec, Katarzyna M.
• Format: Article
• Language: English
• Subjects: Fourier transform infrared spectroscopy; Haemoglobin, 2,3-DPG; Red blood cells
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2022.121819

[Display omitted] •Sex, age, and disease progression have an impact on red blood cells (RBCs);•Sex-related differences are prominent in older ApoE/LDLR-/- mice;•Female RBCs are less prone to the alterations with progression of atherosclerosis;•2,3-DPG levels in RBCs show link to the hemoglobin secondary structure alterations. In the present study, we characterized the secondary structure alterations of intact red blood cells (RBCs) cytosol with special attention to the sex-related alterations in 8- and 24-week-old female and male ApoE/LDLR-/- mice, compared to age-matched female and male C57BL/6J control animals. Results were obtained with previously established methodology based on Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR). Additionally, we evaluated 2,3-DPG levels in the RBCs and showed its potential link to the hemoglobin (Hb) secondary structure alterations. Considering Hb structure alterations probed by FTIR-ATR, the ratio of turns to α–helices in 8-week-old ApoE/LDLR-/- mice suggested more pronounced secondary structure alterations within the RBCs than in the age-matched control. Sex-related differences were observed solely in 24-week-old male ApoE/LDLR-/- mice, which showed statistically significant increase in the secondary structure alterations compared to 24-week-old female ApoE/LDLR-/- mice. Similar to the secondary structure alterations, no sex-related differences were observed in the levels of 2,3-DPG in RBCs, except for 24-week-old male ApoE/LDLR-/- mice, which showed significantly higher levels compared to the age-matched female ApoE/LDLR-/- mice. Considering the age-related alterations, we observed significant increases in the intracellular 2,3-DPG of RBCs with animals’ age in all studied groups, except for female ApoE/LDLR-/- mice, where a significant difference was not reported. This suggests the clear correlation between secondary structure of Hb alterations and 2,3-DPG levels for male and female murine RBC and proves a higher resistance of older female RBCs to the secondary structure changes with progression of atherosclerosis. Moreover, it may be concluded that higher 2,3-DPG levels in RBCs occurred in response to the secondary structure alterations of Hb in ApoE/LDLR-/- mice.