The influence of fluoride on expression of OPGL and M-CSF genes and their proteins in rats with experimental fluorosis and the therapeutic effect of Danlan Xianpeng Liaofu caspule / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate mRNA and protein expressions of OPGL and M-CSF mRNA in bones of rats with experimental fluorosis induced by intake of fluoride in the drinking water, and to study the antagonizing effects of Danlan Xianpeng Liaofu capsules on the gene expression.</p><p><b>METHODS</b>Totally 72 SD rats were randomly assorted into 6 groups including the control group, the fluoride group, the high-dosage (0.8 g/kg×d), mid-dosage (0.4 g/kg×d) and low dosage (0.2 g/kg×d) medication groups and the borax group (borax, 0.8 g/kg×d). The distribution of female and male rats in each group was divided up on a fifty-fifty basis. Except the control group, a NaF containing water (NaF 50 mg/L in concentration) was supplied as the drinking water for all the experimental rats in order to establish experimental fluorosis. The thickness and density of trabecula and the thickness of bone cortex were measured by light microscopy. The fluoride content in urine and bone were analyzed by using fluoride ion selective electrode method. Expressions of OPGL and M-CSF mRNA and protein were studied using RT-PCR and immuno-histochemistry, respectively.</p><p><b>RESULTS</b>(1) 10/12 of the experimental fluorosis rats developed dental fluorosis, and 2/12 of dental fluorosis rats occurred in the low-dosage medication group. Fluoride content in urine and bone of the fluorosis rats increased (P<0.05). (2) Compared with that of the control rats, the bone trabecular depth, cortical thickness and trabecular density in experimental fluorosis rats were remarkably reduced. (3) Compared with that of the control group, mRNA expression of both OPGL and M-CSF was increased in the fluoride group rats. The difference was statistically significant (P<0.05). (4) Compared with that of the fluoride group animals, the expression intensity of OPGL mRNA decreased in animals of the control group, the high, mid- and low- dosage medication groups and the borax group. Among them, except the low-dosage group, the difference between all the other groups and the fluoride group was statistically significant, respectively (P<0.05). There was also a decrease of M-CSF mRNA in all the 3 medication groups and the borax group animals in comparing with that of the fluoride group and the difference was also statistically significant (P<0.05), respectively. (5) Compared with that of the control group. There were an increase of OPGL and a decrease of M-CSF protein expression; and in addition, there were a decrease of OPGL and an increase of M-CSF protein expression in all 3 medication groups and the borax group in comparing with that of the fluoride group anima (P < 0.05).</p><p><b>CONCLUSIONS</b>Excessive fluoride induces an accelerated bone turnover and may promote the absorption activity of osteoclasts by increasing the expression of OPGL and M-CSF. Danlan Xianpeng Liaofu capsule may be capable of regulating bone remodeling through a down-regulation on OPGL and M-CSF expression.</p>

Effect of fluoride on the expression of osteoprotegerin/receptor activator of nuclear factor κβ ligand/receptor activator of nuclear factor κβ system proteins of rats with fluorosis and the antagonism of Danlan Xianpeng capsule / 中国地方病学杂志

Objective To observe the expression of osteoprotegerin (OPG), receptor activator of nuclear factor κβ ligand(RANKL) and receptor activator of nuclear factor κβ (RANK) in bone tissue of rats with chronic fluorosis and to explore the relation between OPG/RANKL/RANK system and bone damage in chronic fluoride poisoning rat and the antagonism effects of Danlan Xianpeng capsule. Methods SD rats were randomly divided into six groups according to body weight (equal male and female in each group): fluorosis group, high dose drug group, medium dose drug group, low dose drug group, control group, borax group(positive control), 12 rats in each group. The control group drank tap water and the remaining 5 experimental groups consumed 50 mg/L fluoride water, and high, medium and low doses drug group took Danlan Xianpeng capsule at doses of 0.8,0.4,0.2 g/kg,borax group took borax at dose of 0.8 g/kg. OPG, RANKL, RANK protein in rat tibial metaphysis was detected by immunohistochemistry at the 6 month. Results Compared with the control group(173.79 ± 5.23, 174.17 ± 5.01,155.63 ± 7.11), the expressions of OPG, RANKL were increased and the expression of RANK was decreased in fluorosis group(156.83 ± 5.80, 157.74 ± 6.70, 173.92 ± 4.37), the difference was statistically significant (all P ＜ 0.05). Compared with the fluorosis group, the expression of OPG and RANKL were decreased and the expression of RANK was increased in high-dose drug group, middle-dose drug group(169.67±5.07, 168.08 ± 5.05,162.12 ± 4.24, 170.78 ± 5.01, 168.41 ± 7.19, 166.69 ± 5.78, all P ＜ 0.05). Compared with the borax group (167.27 ± 4.08, 167.85 ± 5.01, 166.14 ± 3.95), the expression of OPG and RANKL was increased in the low-dose drug group (163.40 ± 4.11, 159.49 ± 5.78), the expression of RANK was increased in the high-dose drug group (162.12 ± 4.24) and decreased in the low-dose drug group(171.54 ± 8.06), the difference was statistically significant (all P ＜ 0.05). Conclusions Chronic fluoride poisoning can cause increased bone turnover and enhance the activity of osteoelastic absorption by increasing RANKL. Danlan Xianpeng capsule can affect bone remodeling through the OPG/RANKL/RANK system, and antagonises bone damage caused by fluoride.