Wei SL, Ge QD, Zeng ZD, Zhang H, Xie C. - "Effects of exposure of fluoride combined with aluminum from pregnancy to adulthood on miR-21 in bone tissue and TRACP-5b in serum of offspring rats" J Environ Health 35(7):569-574 (2018) [Chinese]
目的了解妊娠期至成年期氟铝联合暴露对子代大鼠骨组织中miR-21及血清中抗酒石酸酸性磷酸酶-5b(TRACP-5b)的影响。方法将36只健康成年清洁级SD孕鼠随机分为9组,分别为对照(自来水)组和氟化钠(60、240mg/L)、氯化铝(600、1 000 mg/L)染毒组及氟化钠+氯化铝联合染毒组,每组4只。采用自由饮水方式染毒,母鼠染毒从妊娠第0天至子代大鼠出生第21天(断乳);断乳后从每组随机选取8只子代大鼠(雌雄各半)延续同组剂量染毒至出生后第90天。采用氟离子选择电极法测定尿氟、骨氟,采用石墨炉原子吸收光谱法测定尿、骨中铝含量,采用实时荧光定量PCR (qRT-PCR)检测骨组织中miR-21的表达水平。采用固相夹心ELISA法检测血清中抗酒石酸酸性磷酸酶-5b(TRACP-5b)的含量。结果与对照组比较,除单独氯化铝染毒组和60 mg/L NaF+1 000 mg/L氯化铝染毒组外,其余染毒组仔鼠的尿氟浓度均升高(P<0.05);除单独NaF染毒组和240 mg/L NaF+600 mg/L氯化铝染毒组外,其余染毒组仔鼠的尿铝浓度均升高(P<0.05);除单独氯化铝染毒组和60 mg/L NaF+1 000 mg/L氯化铝染毒组外,其余染毒组仔鼠骨氟含量均升高;单独氯化铝染毒组和240 mg/L NaF+1 000 mg/L氯化铝染毒组仔鼠的骨铝含量均升高(P<0.05)。尿氟浓度在各浓度NaF+氯化铝联合染毒组中均表现为拮抗作用(P<0.05);尿铝浓度在60 mg/L NaF+1 000 mg/L氯化铝联合染毒组中均表现为协同作用,在其余各浓度NaF+氯化铝联合染毒组中均表现为拮抗作用(P<0.05);骨氟含量在各浓度NaF+氯化铝联合染毒组中均表现为拮抗作用(P<0.05);骨铝含量在各浓度NaF+氯化铝联合染毒组中未见交互作用(P>0.05)。与对照组比较,240 mg/L NaF染毒组和60 mg/L NaF+1 000 mg/L氯化铝染毒组、240 mg/L NaF+1 000 mg/L氯化铝染毒组仔鼠血清中TRACP-5b的水平均降低(P<0.05);60 mg/L NaF染毒组、1 000 mg/L氯化铝染毒组和60 mg/L NaF+600 mg/L氯化铝染毒组、240 mg/L NaF+600 mg/L氯化铝染毒组仔鼠骨组织中miR-21的表达水平均升高(P<0.05)。氟铝联合染毒对血清中TRACP-5b水平的影响表现为拮抗作用。氟铝联合染毒对不同性别仔鼠骨组织中miR-21表达的影响均存在交互作用(P<0.05);对不同性别仔鼠骨组织中miR-21表达的影响在60 mg/L NaF+600 mg/L氯化铝染毒组、240mg/L NaF+600 mg/L氯化铝染毒组中均表现为协同作用(P<0.05),在其余联合染毒组中表现为拮抗作用(P<0.05)。结论氟铝联合暴露可能通过升高骨组织中miR-21表达和降低血清中TRACP-5b水平,从而促进妊娠期至子代大鼠成年前仔鼠骨组织中破骨细胞的活性。
Objective
To investigate the effects of combined fluoride and aluminum exposure from pregnancy to adulthood on offspring rats’ bone tissue expression of miR-21 and serum tartrate-resistant acid phosphatase-5b (TRACP-5b).
Methods
Thirty-six healthy, adult, specific pathogen–free SD pregnant rats were randomly divided into 9 groups:
Control (tap water),
Sodium fluoride (NaF) exposure groups (60, 240 mg/L),
Aluminum chloride (AlCl₃) exposure groups (600, 1,000 mg/L),
Combined NaF + AlCl₃ exposure groups (various concentrations).
Each group had 4 dams. Exposure was via drinking water from gestational day 0 until postnatal day 21 (weaning). After weaning, 8 offspring (equal males and females) were randomly selected from each group and continued on the same exposure regimen until day 90 after birth.
Measurements:
Urinary fluoride and bone fluoride: fluoride ion-selective electrode.
Urinary aluminum and bone aluminum: graphite furnace atomic absorption spectrophotometry.
miR-21 expression in bone tissue: qRT-PCR.
Serum TRACP-5b levels: solid-phase sandwich ELISA.
Results
Urinary fluoride: Elevated in most exposed groups (P<0.05), except the AlCl₃-only group and the 60 mg/L NaF + 1,000 mg/L AlCl₃ group.
Urinary aluminum: Elevated in most exposed groups (P<0.05), except the NaF-only groups and the 240 mg/L NaF + 600 mg/L AlCl₃ group.
Bone fluoride: Elevated in most groups, except the AlCl₃-only group and the 60 mg/L NaF + 1,000 mg/L AlCl₃ group.
Bone aluminum: Elevated only in the AlCl₃-only group and in the 240 mg/L NaF + 1,000 mg/L AlCl₃ group (P<0.05).
Interactions:
Urinary fluoride: antagonistic effect in all combined exposure groups (P<0.05).
Urinary aluminum: synergistic effect in the 60 mg/L NaF + 1,000 mg/L AlCl₃ group, antagonistic in all other combined groups (P<0.05).
Bone fluoride: antagonistic in all combined exposure groups (P<0.05).
Bone aluminum: no interaction effect in combined exposure groups (P>0.05).
Biochemical markers:
TRACP-5b: Decreased in the 240 mg/L NaF group and in the 60 mg/L NaF + 1,000 mg/L AlCl₃ and 240 mg/L NaF + 1,000 mg/L AlCl₃ groups (P<0.05).
miR-21: Increased in bone tissue of offspring in the 60 mg/L NaF group, 1,000 mg/L AlCl₃ group, 60 mg/L NaF + 600 mg/L AlCl₃ group, and 240 mg/L NaF + 600 mg/L AlCl₃ group (P<0.05).
Sex-based effects:
Combined fluoride–aluminum exposure showed interactive effects on miR-21 expression in bone tissue of offspring of different sexes (P<0.05).
Synergistic effects were seen in the 60 mg/L NaF + 600 mg/L AlCl₃ and 240 mg/L NaF + 600 mg/L AlCl₃ groups (P<0.05).
Antagonistic effects were observed in the other combined exposure groups (P<0.05).
Conclusion
Combined fluoride and aluminum exposure from pregnancy to offspring adulthood may enhance osteoclast activity in bone tissue by:
Increasing bone miR-21 expression, and
Decreasing serum TRACP-5b levels.