Relationship between mRNA expression of MnSOD and manganese neurotoxicity / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between mRNA expression of manganese superoxide dismutase (MnSOD) and manganese neurotoxicity.</p><p><b>METHODS</b>Thirty-one patients with occupational chronic manganese poisoning (case group), as well as 31 controls exposed to the same condition (control group), were included in the study. Whole blood RNA was extracted, and the mRNA expression of MnSOD was measured by RT-PCR; the two groups were compared in terms of the mRNA expression of MnSOD. PC12 cells were treated with 0, 100, 200, 400, 600, 800, and 1000 ümol/L MnCl₂ for l, 2, 3, and 4 d; the cell viability was determined by MTT assay, and the mRNA expression of MnSOD was measured by RT-PCR.</p><p><b>RESULTS</b>The case group had significantly lower mRNA expression of MnSOD than the control group (0.390 ± 0.080 vs 0.582 ± 0.219, P < 0.05). MnCl2 had a toxic effect on PC12 cells; the concentration of MnCl₂ was positively correlated with the toxic effect but negatively correlated with the mRNA expression of MnSOD.</p><p><b>CONCLUSION</b>MnSOD mRNA may be involved in the manganese-induced damage of nerve cells. It is hypothesized that high mRNA expression of MnSOD may play an inhibitory effect on manganese neurotoxicity.</p>

Relationship between MnSOD polymorphisms and susceptibility of chronic poisoning exposed to manganism occupationally / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the relationship between polymorphisms of MnSOD and the susceptibility of chronic poisoning exposed to manganism occupationally.</p><p><b>METHODS</b>In a study of case-control, genotypes were determined by PCR-RFLP in 164 patients with chronic occupational mangamism poisoning and 328 controls with age- and sex-matched for MnSOD 9Ala-Val.</p><p><b>RESULTS</b>There was a significant difference in the frequency of MnSOD 9Ala-Val at V locus mutant allele between cases and controls (χ(2) = 15.225, P < 0.01, 95%CI = 1.43 ∼ 3.00). Individuals with the genotype VV had a 1.30 of risk increase of occupational chronic manganism poisoning compared with the the genotype AV or AA (OR = 2.30, 95%CI = 1.52 ∼ 3.49, P < 0.05).</p><p><b>CONCLUSION</b>The MnSOD polymorphisms may be related with the susceptibility to chronic occupational manganism poisoning, the risk of chronic occupational manganism poisoning increases in carriers with genotype VV at MnSOD 9Ala-Val locus.</p>