Human Neonatal Thymus Mesenchymal Stem Cells Promote Neovascularization and Cardiac Regeneration

Figure 1

(a) Subject-matched ntMSCs possess a higher Shh expression as compared to nbMSCs. All cells were cultured in monolayers prior to analysis. Comparison performed with a paired t-test. (b) Shh cellular protein levels are higher in ntMSCs as compared to adult bone (a, b) MSCs and subject-matched nbMSCs (numbers denote subject). As another comparison, Shh content was also measured in monolayer-cultured HUVECs. (c) Conditioned media from ntMSCs contained a higher concentration of Shh than that from subject-matched nbMSCs as determined by ELISA. Mean ± SD is shown of three technical replicates. Data is representative of two independent experiments performed with MSCs isolated from two subjects. (d) Hanging drop culture of ntMSCs stimulated Shh expression. Data are from ntMSCs from five subjects and comparison was performed with a paired t-test. (e) Hanging drop culture stimulated Shh secretion. Conditioned media was generated from HUVECs and subject-matched nbMSCs and ntMSCs cultured in monolayers of hanging drops. Hanging drop culture of HUVEC + ntMSCs stimulated the most Shh secretion. (f) Experimental setup to determine the cytoprotective effects of ntMSCs on H₂O₂-induced death of neonatal rat CMs. Controls were exposed to H₂O₂ in the absence of ntMSCs. The second group contained ntMSCs cultured on an insert, thereby sharing the same media but was physically separated from the CMs. The third group containing ntMSCs cocultured with CMs on the same culture surface permitted direct contact between the two cell types. (g) H₂O₂ induced apoptosis in all groups but was decreased in the presence of ntMSCs. The most cytoprotection was seen when ntMSCs were cultured in direct contact with the CMs. Results are representative of two independent experiments. (h, i) TUNEL staining confirmed that the presence of ntMSCs prevented apoptosis. Results are representative of two independent experiments. Scale bar = 100 μm (h).