Parkinson’s disease’s etiology is unknown, although evidence suggests the involvement of oxidative modifications of intracellular components in disease pathobiology. Despite the known involvement of the extracellular matrix in physiology and disease, the influence of oxidative stress on the matrix has been neglected. The chemical modifications that might accumulate in matrix components due to their long half-live and the low amount of extracellular antioxidants could also contribute to the disease and explain ineffective cellular therapies. The enriched striatal extracellular matrix from a mouse model of Parkinson’s disease was characterized by Raman spectroscopy. We found a matrix fingerprint of increased oxalate content and oxidative modifications. To uncover the effects of these changes on brain cells, we morphologically characterized the primary microglia used to repopulate this matrix and further quantified the effects on cellular mechanical stress by an intracellular fluorescence resonance energy transfer (FRET)-mechanosensor using the U-2 OS cell line. Our data suggest changes in microglia survival and morphology, and a decrease in cytoskeletal tension in response to the modified matrix from both hemispheres of 6-hydroxydopamine (6-OHDA)-lesioned animals. Collectively, these data suggest that the extracellular matrix is modified, and underscore the need for its thorough investigation, which may reveal new ways to improve therapies or may even reveal new therapies.This research was funded by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE 2020 Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020, and Portuguese funds through FCT (ID/BIM/04293/2020), UnIC (UID/IC/00051/2019), iBiMED (UID/BIM/04501/2020 and POCI-01-0145-FEDER-007628), and LAQV/REQUIMTE (UIDB/50006/2020) research units as well as RV’s Fellowship Grant (IF/00286/2015). Ana Freitas acknowledges FCT for her PhD scholarship (SFRH/BD/111423/2015), Miguel Aroso is hired through the Scientific Employment Stimulus from FCT (CEECIND/03415/2017), and M.L. has an FCT RJEC Id 3762 contract.The authors thank Eduardo D Martín Montiel for his support, fruitful discussions, suggestions, and technical and scientific help. The authors also thank Sofia Lamas and all the i3S Animal facility personnel for their support with the animals throughout the study. Raman spectroscopy, together with wide field and confocal microscopy, were performed at the i3S Scientific Platform Bioimaging, member of the PPBI (Plataforma Portuguesa de Bioimagem, POCI-01-0145-FEDER-022122)
