Sema4D/Plexin-B1在氟性骨损伤发生中作用的实验研究

The role of Sema4D/Plexin-B1 in the occurrence of fluorous bone injury

目的探讨信号素4D(Sema4D)及受体丛状蛋白B1(Plexin-B1)在氟性骨损伤发生中的作用。方法 SPF级SD大鼠48只,随机分为1个对照组和3个染氟组,采用氟化钠(NaF)溶液饮水染毒,3个染氟组NaF染毒浓度分别为1.6、16和32 mg/kg。在染氟第0天、第15天、第30天和第90天时,进行大鼠尾动脉取血,分别测定各时段血氟(微量电极法)、ALP(全自动生化分析仪法)和Sema4D/Plexin-B1(ELISA法)。结果染氟30 d后,3个染氟剂量组大鼠均发生氟斑牙,表现为下切牙色泽度差,表面棕、白色带增宽,横纹不规则甚至消失,并可见牙齿缺损。大鼠血氟与ALP随染毒剂量增加和时间延长呈升高趋势,与对照组比较,差异有统计学意义(P<0.01)。大鼠Sema4D含量在染氟第15天开始降低,组间比较,差异有统计学意义(P<0.05)。染氟第30天,高剂量组(12.20±0.73 ng/1L)和中剂量组(13.70±0.68 ng/L)大鼠Sema4D含量下降明显,与对照组(19.20±0.68 ng/L)比较差异有统计学意义(P<0.01)。染氟第90天,高、中、低剂量组大鼠Sema4D含量分别为(11.14±0.66)、(11.73±0.68)和(13.72±0.71)ng/L,与对照组(19.87±0.69 ng/L)比较明显降低(P<0.01)。大鼠Plexin-B1含量也随着染氟时间的延长而有所下降,且高、中2个剂量组大鼠Plexin-B1含量下降较为明显,与对照组比较,差异有统计学意义(P<0.01)。结论染氟组大鼠血清中Sema4D和Plexin-B1表达量明显降低,大鼠氟性骨损伤的发生可能与Sema4D/Plexin-B1表达水平有关。

Objective To investigate the role of the Semaphorin4 D（Sema4 D） and Plexin B1 in the occurrence of fluorous bone injury. Methods 48 rats of SPF grade SD rats were randomly divided into one control group and three experimental groups exposed to sodium fluoride（ NaF） by drinking water. The concentrations of NaF were 1.6,16 and 32 mg/kg respectively. At the time of Od,15 d, 30 d and 90 d,collecting the rat tail artery, the blood fluorine（ micro-electrode method）,ALP（ automatic biochemical analyzer）and Sema4 D/Plexin-B1（ELISA） were collected and determined. Results After 30 d of fluoride exposure,dental fluorosis in the three experimental groups showed low colour and lustre degree, surface brown and white band broadening, irregular stripes or even disappeared, and visible teeth defect in lower incisors. With the increase of exposure in doses and time, blood fluoride and ALP also increased,and the difference was statistically significant（ P〈0. 01）, compared with the control group. At the 15 d,the expression of Sema4 D decreased significantly（P〈0. 05） in groups. At the 30 d,Sema4 D of high dose group（12. 20 ± 0. 73 ng/L）and middle dose group（13. 70± 0. 68 ng/L） decreased significantly（P〈0. 01）,compared with the control group（19. 20 ± 0. 68 ng/L）. After 90 days of fluoride exposure, the Sema4 D concentrations of three dose groups were 11. 14±0. 66 、 11. 73 ± 0. 68 and 13. 72± 0. 71 ng/L respectively, which significantly reduced（P〈0. 01）, compared with the control group（ 19. 87 ±0. 69 ng/L）. The expression of Plexin-B1 decreased with the prolongation of staining time, but the expression of Plexin-Bl in the high and middle dose groups was significantly lower than that in the control group（P〈0. 01）. Conclusions The levels of Sema4 D and Plexin-B1 in serum of rats exposed to fluoride were significantly decreased,and the occurrence of fluorine bone injury in rats may be related to the expression of Sema4 D/Plexin-B1.