Abstract 573: Vibrational Spectroscopy Discriminates Differentiated Vascular Smooth Muscle Cells From Mesenchymal Stem Cells and Their Vascular Progeny

Abstract

Background: The source of intimal vascular smooth muscle cells (SMCs) following vascular remodelling has been controversial, with either de-differentiated SMCs and/or stem cell-derived SMCs playing a putative role. Fourier transform Infrared (FTIR) and Raman spectroscopy are complementary forms of vibrational spectroscopy which provide an excellent platform for extracting important biochemical data in a label-free manner to discriminate cell types. Aim: Determine whether native differentiated SMCs can be distinguished from mesenchymal stem cells (MSCs) and MSC-derived SMCs using vibrational spectroscopy. Methods: Freshly isolated rat aortic differentiated SMCs (up to passage 4), CD44+ bone marrow derived mesenchymal stem cells (MSCs), MSC-derived smooth muscle cells (mdSMCs - after TGF-β1 treatment for 14 d) and osteoblasts (mdOSTs - after osteogenic inductive stimulation for 21 d) were grown and fixed on calcium fluoride slides before their respective spectra were recorded by Raman and FTIR Spectroscopy. Multivariate statistical algorithms, including Principal Components Analysis (PCA) and Linear Discriminant Analysis (LDA), were applied to the spectra in order to classify the cell types based on their biochemical variation. Results: The recorded spectra for each cell type revealed significant visible differences between the cells across all recordings. The PCA score plot discriminated the cells based on their unique characteristics. A combination of PCA-LDA were applied for classification, and a leave one out cross validation resulted in sensitivities and specificities that were >95%. Conclusion: Vibrational spectroscopy discriminates differentiated SMCs from MSC and their vascular progeny and may be useful for identifying these cells as early biomarkers of disease.