Optical spectroscopic analysis of biochemical changes using infrared spectral discrimination of transgenic mice serum to study the potential correlation of the nanostructural disorder alterations for neurological diseases

We investigated biochemical changes in the serum of Alzheimer’s and Parkinson’s disease (AD/PD) mouse models relative to their control using FTIR spectroscopy. This study corroborates the structural modifications and nanoscale structural disorder, with techniques like Inverse Participation (IPR) within macromolecules such as DNA and RNA, in AD/PD conditions. Serum samples (1μL) were analyzed using a Jasco ATR Pro 4x FTIR spectrometer in the mid-infrared range. Secondary protein analyses were performed on the spectra using identified AD/PD biomarkers from a previous study. Quantification of these identified biomarkers was performed using curve-fitting analysis, which indicated statistically significant changes in the β-sheet/Tyrosine ratio. The experimental results show an accumulation of intermolecular β-sheets associated with amyloid β/tau changes. Additionally, marked changes in lipid-protein balance were observed, demonstrating the role of lipids in modulating the structure/function of the subcellular membrane, which served as a distinctive parameter for distinguishing disease from control states. This serum-based spectroscopic analysis complements our previously conducted nanoscale disorder studies in mouse brain tissues. By combining brain and serum biomarkers, we aim to provide a translational framework that bridges central pathology to systemic signatures and underscores the potential of FTIR-based biomarkers for early diagnosis of AD/PD.