Objective To examine the effects of cadmium on self-renewal ability and expression of metallothionein (MT) gene isoforms of human embryonic neural stem cells (hNSCs).
Methods Treatment with 0, 1.25, 2.5, and 5 μmol/L cadmium chloride (CdCl2) for 24 h was provided for hNSCs. Cell viability was measured by methyl thiazolyl tetrazolium (MTT) assay, cell proliferation by 5-ethynyl-2'-deoxyuridine(EdU) assay, and lactic acid dehydrogenase (LDH) activity by spectrophotometric method. The mRNA expression of 10 MT isoforms in hNSCs after exposure to cadmium was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR).
Results Compared with the control group, treatment with 2.5 and 5 μmol/L CdCl2 for 24 h significantly reduced the cell viability (P < 0.01); the cell viability was negatively correlated with the concentrations of CdCl2 (r=-0.98, P < 0.01). Treatment with 1.25 μmol/L and above remarkably inhibited DNA replication (P < 0.05), and the cell proliferation was negatively correlated with log-transformed CdCl2 concentrations (r=-0.91, P < 0.01). Compared with the control group, all CdCl2 treatments for 24 h significantly increased the activities of LDH in supernatant (all P < 0.01), and the activities of LDH and the concentration of CdCl2 showed a positive correlation (r=0.97, P < 0.01). The mRNA expression levels of MT gene isoforms were significantly increased with higher concentrations of CdCl2 (P < 0.05).
Conclusion Cadmium could restrain the self-renewal ability of hNSCs via cell viability reduction, LDH activity elevation in hNSCs culture medium, and significant up-regulated mRNA expression of MT gene isoforms.
DownLoad: