A study of mRNA expressi on and transcription regulation in the promoter region of myeloperoxidase gene from a population living in the area with coal-burning endemic fluorosis in Guizhou Province

Abstract

Objective To explore the correlation between myeloperoxidase （MPO） genetic variation and coal-burning endemic fluorosis, and to understand the influence of integrated intervention including stove changes and health education on people’s health in the area. Methods In 2007, coal-burning endemic fluorosis disease areas were selected in Bijie City, Guizhou Province. No stove changes in Yachi Town, 150 patients with dental fluorosis were selected as fluorosis non-intervention group, and the intervention group was 150 patients in Changchun Town where the stoves were changed 2 years ago. The population in control group was selected in an area with non-endemic fluorosis in Changshun County. The mRNA expressions of MPO in leukoxytes were detected by real-time PCR. HepG2 cells were cultured in vitro and divided into four groups： pGL3-A group, pGL3-G group,＆amp;nbsp;pGL3-Control group and pGL3-Basic group. pGL3-A and pGL3-G were recombinant plasmid, while pGL3-Basic as a blank control and pGL3-Control as a positive one. The internal reference plasmid pRL-TK co-transfected the HepG2 cells with pGL3-G, pGL3-A, pGL3-Basic and pGL3-Control, respectively. The influence of sudden change of MPO gene promoter on the gene transfection activity was evaluated by a dual luciferasereporter gene system. Results The expression level of MPO mRNA in peripheral blood leukocytes in non-intervention group（0.054 ± 0 . 003 ） were higher than control and intervention groups （0.019 ± 0.004,0.019 ± 0.003, all P〈0.05）, and no significant change was found between intervention group and control group（P〉0.05）. After the MPO-463G/A locus genetic variation occured, the luciferase reporter gene expression level of the recombinant plasmid pGL3-G（0.753 4 ± 0.086 6） was higher than that of the pGL3-A（0.490 0 ± 0.022 3, P 〈 0.05）. Conclusions The study on MPO gene promoter-463G/A locus has prompted that MPO gene allele may be a protective factor to coal-burning fluorosis. The integrated interventions have a role in the prevention and treatment of endemic fluorosis. Key words: Oxidative stress; Myeloperoxidase; Coal-burning fluorosis