Discriminant principal component analysis of ToF-SIMS spectra for deciphering compositional differences of MSC-secreted extracellular matrices
In this study [1], ToF-SIMS was applied to detect subtle differences between human mesenchymal stromal cell (MSC)-secreted extracellular matrix (ECM) types as induced by exogenous stimulation or emerging pathology. Spectra measured for decellularized ECM samples were evaluated by discriminant principal component analysis (DPCA) to decipher characteristic compositional features. To establish the approach, signatures of the ECM proteins collagen I, fibronectin, and laminin-111 were determined and verified by the analysis of pre-defined mixtures. Based on that, sets of ECM variants produced by MSCs in vitro were analyzed. Differences in the content of collagens, fibronectin, and laminins in the ECM resulting from the combined supplementation of MSC cultures with polymers that induce macromolecular crowding and with ascorbic acid were detected from the DPCA of ToF-SIMS spectra and verified by immunostaining. Finally, the comparative ToF-SIMS analysis of ECM produced by MSCs of healthy donors and patients suffering from myelodysplastic syndrome (MDS) displayed the potential of the novel methodology to reveal disease-associated alterations of the ECM composition.
Workflow for the ToF-SIMS analysis of extracellular matrices. (A) MSC isolation and culture, followed by decellularization and desalting steps. (B) ToF-SIMS analysis of multiple replicates for each culture condition. (C) Scores and loadings of DPCA of the mass spectra collected for ECM samples from cultures with graded supplementation of ascorbic acid (ASC) and FiColl (FC) indicate ASC boosted collagen synthesis and elevated collagen, fibronectin, and laminin secretion under crowding conditions (supplement of FC). For details see Ref. [1].
References:
[1] Zimmermann et al. Small Methods 2023, 2201157, doi: https://doi.org/10.1002/smtd.202201157