Fig. 1

Netrin-1 is preferentially expressed and secreted by Wharton’s jelly-derived mesenchymal stem cells (WJ-MSC), whilst Netrin-4 expression is almost absent. Netrin-1 (NTN-1) and Netrin-4 (NTN-4) expression was confirmed by different experimental techniques. a Representative images of the histological analysis of umbilical cord sections are shown. MSCs uniformly distribute within Wharton’s jelly and show positive staining for Alcian Blue and Netrins (magnification × 20). Inset show optical zoom images of NTN-1 and NTN-4 staining (n = 3). b Flow cytometry and immunofluorescence anti-NTN-1 and −4 confirm preferential expression of NTN-1 in WJ-MSC (n = 3) (magnification × 63). c Western blot for NTN-1, NTN-4 and vascular endothelial growth factor (VEGF) (positive control) in whole cell lysate (CL) and conditioned media (CM) of WJ-MSC cultures. β-actin (for CL) and Ponceau (for CM) were used as internal loading controls, respectively (n = 3–7). d ELISA analysis for NTN-1 in WJ-MSC; CM was obtained at indicated time points (n = 4). e Western blot for NTN-1 in WJ-MSC, seeded 24 h in Integra® matrix (IM) or collagen I (Col), versus respective empty scaffold (−) used as negative control. Ligand expression was analyzed both in CL or CM. β-actin and Ponceau were used as internal loading controls, respectively (n = 4–5)