Histochemistry
To evaluate the presence and distribution of relevant components of the
extracellular matrix (ECM), all tissue samples were subjected to
histochemical methods. To identify the tissue elastic fibers, samples
were stained using Verhoeff histochemical staining method (VHF). To
reveal the presence of fibrillar collagens, we used picrosirius red
(PSR). Non-fibrillar ECM components were evaluated using alcian blue
staining (AB) at pH 2.5 for proteoglycans, and periodic acid–Schiff
staining (PAS) for glycoproteins. All these methods were performed
following previously published standard histochemical methods
(Blanco-Elices et al., 2022; V. S. Carriel et al., 2011; García-García
et al., 2021; Sánchez-Porras et al., 2023).