[Effect of magnesium and selenium on the expression of matrix metalloproteinases-20 and kallikrein 4 in fluorosis mice].
OBJECTIVE
To study the effect of magnesium/selenium on the expression of matrix metalloproteinases-20(MMP-20) and kallikrein 4(KLK4) during fluorosis in mice and to explore the formation mechanism of dental fluorosis.


METHODS
Eighty SPF male ICR mice were randomly divided into 8 groups according to body weight: control group, magnesium group, selenium group, magnesium-selenium group, fluoride group, magnesium-fluorine group, selenium-fluorine group and magnesium-selenium-fluorine group. Mice in control, magnesium, selenium and magnesium-selenium groups were fed double steamed water, and mice in the other four groups were feddouble steamed water with 50 mg/L F(-). Mice in control and fluoride groups were fed conventionally. Mice in magnesium and magnesium-fluorine groups were fed conventionally by adding MgSO4·7H2O 162.5 mg/kg. Mice in selenium and selenium-fluorine groups were fed conventionally by adding Na2SeO3·5H2O 2 mg/kg. Mice in magnesium-selenium and magnesium-selenium-fluorine groups were fed conventionally by adding MgSO4·7 H2O 162.5 mg/kg + Na2SeO3·5H2O 2 mg/kg. Incisor specimens were obtained after the mice were put into death when they were 42 days. The expressions of MMP-20 and KLK4 were observed by using immunohisto-chemicalstain.


RESULTS
The meangray value of MMP-20 of fluoride group(133.1±10.3) was significantly higher than that of control group(116.8±10.0), magnesium group (113.6 ± 9.6), magnesium-selenium group(108.2 ± 15.2), magnesium-fluorine group(111.1 ± 8.1) and magnesium-selenium-fluorine group(108.2 ± 11.0), respectively(F=3.864, P<0.05). The mean gray value of MMP-20 of magnesium-selenium-fluorine group(108.2±11.0) was significantly lower than that of selenium group(125.4 ± 7.9), fluoride group (133.1 ± 10.3) and selenium-fluorine group(126.2 ± 2.8), respectively(F= 3.864, P<0.05). The mean gray value of KLK4 of magnesium-selenium group(117.2±11.7) was significantly lower than others(137.3±7.9 of control group, 144.2±7.7 of magnesium group, 138.9±13.3 of selenium group, 149.7 ± 12.4 of fluoride group, 148.9 ± 7.5 of magnesium-fluorine group, 140.6 ± 17.0 of selenium-fluorine group and 140.7 ± 7.3 of magnesium-selenium-fluorine group, F=3.668, P<0.05). In factorial analysis of fluorosis mice, magnesium had effect on the expression of MMP-20(F=42.613, P<0.05), selenium had effect on the expression of KLK4(F=6.649, P<0.05).


CONCLUSIONS
The excessive fluoride could inhibit the expressions of MMP-20. The excessive fluoride hadno significant influence on the expression of KLK4. Magnesium and selenium had antagonistic effect on the dental fluorosis.
Department of Conservative Dentistry and Endodontics, Stomatological Hospital, College of Medicine, Xi 'an Jiaotong University, Xi 'an 710004, China(Present address: Department of Oral Medicine, Department of Stomatology, Xi'an Medical University, Xi'an 710021, China).
F
F
Wang
Department of Conservative Dentistry and Endodontics, Stomatological Hospital, College of Medicine, Xi 'an Jiaotong University, Xi 'an 710004, China.
T Z
TZ
Hou
Department of Conservative Dentistry and Endodontics, Stomatological Hospital, College of Medicine, Xi 'an Jiaotong University, Xi 'an 710004, China.
J J
JJ
Li
Department of Oral Medicine, Department of Stomatology, Xi 'an Medical University, Xi 'an 710021, China.
Z Z
ZZ
Li
Department of Oral Medicine, Department of Stomatology, Xi 'an Medical University, Xi 'an 710021, China.
C F
CF
Tang
D000818:Animals; D005458:Fluoride Poisoning; D005459:Fluorides; D009050:Fluorosis, Dental; D007610:Kallikreins; D008274:Magnesium; D008297:Male; D053519:Matrix Metalloproteinase 20; D051379:Mice; D008813:Mice, Inbred ICR; D010710:Phosphates; D012643:Selenium
D010710:Phosphates; C012980:fluorophosphate; D007610:Kallikreins; C120801:kallikrein 4; D053519:Matrix Metalloproteinase 20; D012643:Selenium; D008274:Magnesium; D005459:Fluorides