Fig. 1.

Neuropeptide Y (NPY)-pretreated mesenchymal stem cells (MSC) induced expression of specific genes under hypoxic conditions. To determine the effect of NPY on cardiomyocyte differentiation and proliferation, quantitative real-time PCR was performed using rat MSC (A). NPY-pretreated MSC significantly increases expression of cell cycle regulators including aurora B kinase, fibroblast growth factor-2 (FGF-2), cyclin A2, eukaryotic initiation factor 4 E (eIF4E), and stromal cell-derived factor-1α (SDF-1α). The expression of genes was further increased by treatment with FGF and NPY. The expression of genes was significantly increased in FGF-treated group for aurora B kinase, cyclin A2, and eIF4E, respectively, compared with NPY treatment alone, but was not increased further for SDF-1α. Veh, vehicle-pretreated MSCs; N + F, NPY plus FGF-pretreated MSC (n = 4 in each group). *P ≤ 0.05 was considered statistically significant. All values were expressed as means ± SE. B: ELISA results for release of VEGF in vehicle and NPY-pretreated MSC groups under normoxic, immediately after 8-h hypoxic conditions. *P ≤ 0.05 was considered statistically significant. All values are expressed as means ± SE (n = 6 for each group). C: quantitative data for chemotaxis experiments by using transwells. *P ≤ 0.05 was considered statistically significant. All values are expressed as means ± SE (n = 4 in each group). NPY + siR, MSC-treated with small interfering RNA (siRNA) targeting CXCR4. D: Western blot to verify CXCR4 expression in NPY-treated MSCs. CXCR4 upregulation by NPY was determined by Western blotting under condition of normoxic and hypoxic conditions (A). Quantification of CXCR4 expression in NPY-treated MSC was shown in E. Nor, normoxia; Hypo, hypoxia.