Zinc enhances the cell adhesion, migration, and self-renewal potential of human umbilical cord derived mesenchymal stem cells

Figure 4 Colony forming unit assay and transcriptional analysis of cell cycle and proliferation genes. A: Colonies after crystal violet staining in control and test groups. Denser colonies were observed in ZnCl₂ treated group. Images were captured at 4 × magnification; B: A significantly higher number (^cP ≤ 0.001) of colonies was observed in ZnCl₂ treated group with a mean number of 37 ± 0.57 colonies per T25 flask as compared to control i.e., 15 ± 0.57 colonies per T25 flask. Results were analyzed by SPSS, performing an independent sample t-Test. C: Gene expression of cell cycle genes CDC20, CCNA2, CDCA2 was significantly increased in the test group after 12, 24, 48, and 72 h of treatment with 20 µM ZnCl₂. No significant difference was found in CDK1 gene expression after 12, but it was significantly enhanced after 24, 48, and 72 h. This fold change (2^-ΔΔCt) increase in genes expression was highest in the 24-h group. D: Gene expression of proliferation genes transforming growth factor β1 and GDF5 were significantly increased in all temporal groups i.e. 12, 24, 48, and 72 h, of 20 µM ZnCl₂. HIF1α significantly decreased after 12 h but then significantly increased after 24, 48, and 72 h. Results were analyzed by SPSS, performing an independent sample t-Test. Data was represented as mean ± SD (n = 3) where significance level ^aP ≤ 0.05 (^aP ≤ 0.05, ^bP ≤ 0.01, ^cP ≤ 0.001).