Characterization of cataract patients’ lens epithelial cells by using synchrotron based FTIR

Abstract

AbstractPurposeThe mechanisms involved in the process of cataract formation are not yet fully understood. Lens epithelial cells (LECs) are important for the maintenance of lens transparency as they control energy production, antioxidative mechanisms and biochemical transport for the whole lens. The purpose of this study is to characterize LECs compounds of two different cataract types, nuclear (N) and cortical (C), by using the high resolution synchrotron radiation‐based Fourier Transform Infrared (SR‐FTIR) microspectroscopy.MethodsThe anterior lens capsule (basement membrane and associated LECs) were obtained from cataract surgery and prepared by desiccation for FTIR. Measurements were set to achieve single cell resolution. Data obtained by SR‐FTIR have been analysed by comparing all spectra of N type and C type LECs. The average spectra of each group have been calculated and principal component analysis (PCA) has been performed.ResultsThe first component of the PCA in Amide I area of spectra showed the most prominent contribution at 1625 cm‐1 which is associated with beta sheet organisation in protein aggregates in N cataract type. In the C type we found proteins organized more in the turn and loops conformation (~1670 cm‐1). The markers of oxidative stress: ratios of the asymmetric vibration CH2 and CH3, as well as C=O/lipids showed an increase in C cataract type LECs that pointed out to an increase in lipid peroxidation in this type of LECs. The region corresponds to the P=O asymmetric bands indicate possible difference in protein phosphorylation in C and N types LECs.ConclusionsHere we evaluated the proteins conformation changes, as well as lipids and phosphates bands in LECs of two different cataract types. The oxidative stress and the lipids peroxidation were more pronounced in C type, while protein aggregation is associated with N type. These spectral changes can be assigned to specific biochemical processes occur in two different cataract types LECs.