贵州省地方性氟中毒地区人群GSTP1基因Ile105Val位点多态性分析

Objective To investigate plasma glutathione S-transferase(GSTs) activity and GSTP1 gene Ile105Val polymorphism in Bijie City, Guizhou Province, a coal-burning fluorosis endemic area. Methods One hundred and sixty villagers from Yachi Twon using non-improved cooking stoves were selected as the non-intervened group in Bijie City, Guizhou Province where coal-burning fluorosis was prevailing; 153 villagers as the intervented group were chosen from Changchun Twon, where cooking stoves were improved; 151 villagers were served as the control group from Baiyunshan Twon, Changshun County without endemic fluorosis. The activity of GSTs was tested by colorimetric analysis with spectrophotometer. The genotype of the GSTP1 gene Ile105Val polymorphism, presenting as either homozygous wild-type (AA), or heterozygous mutation type (AG), or homozygous mutation type (GG), was detected through the PCR-RFLP procedure. Results The activity of GSTs in plasma of non-intervened group [(12.44±4.97) kU/L]was significantly lower than that of intervened group (P < 0.05), and that of intervened group[(20.78±6.20)kU/L]was significantly lower than that of control group[(24.30±6.27)kU/L, P< 0.05]. The difference of the enzyme activity of three groups were statistically significant (F = 51.71, P < 0.05), but this enzyme activity did not vary significantly in each sex of each grnup(P > 0.05). Compared intervened group [AA:67.3%(103/153), AG:29.4%(45/153),GG:3.3%(5/153)]and non-intervened group[AA:66.9%(107/160), AG:30%(48/160), GG:3.1%(5/160)]with control group[AA:74.8%(113/151), AG:25.2%(38/151), GG:0 (0/151)], the Ile105Val polymorphism site of GSTP1 gene had significant difference(χ2= 6.04,6.07, both P< 0.05), but not significant between intervened and non-intervened groups(χ2 = 0.02, P>0.05). Conclusions Fluorosis can decrease the activity of GSTs and introduce the GSTP1 gene Ile105Val polymorphism, intervention with the fluorine intake will improve the effect of fluoride on the body.     

燃煤污染型氟中毒大鼠学习记忆能力及胆碱酯酶活性改变

目的 观察燃煤污染型氟中毒大鼠学习记忆能力的变化,探讨其发生机制.方法 健康SD大鼠48只,按染氟剂量分为对照、低氟、高氟3组.低氟组、高氟组大鼠以燃煤型地方病氟中毒重病区燃煤烘烤的当地玉米为主要饲料,复制氟中毒大鼠模型,实验期为3、6个月,各8只大鼠.实验结束时用Morris水迷宫方法检测大鼠行为学变化,并用比色法测定脑组织乙酰胆碱酯酶和丁酰胆碱酯酶活性.结果 染氟剂量对逃避潜伏期时间、第7天穿过平台次数、逗留平台象限时间有明显影响(F值分别为29.29、6.47、6.50,P均<0.01):染氟时间对第7天穿过平台次数和逗留平台象限时间有明显影响(F值分别为16.11、45.59,P均<0.01);染氟剂量和时间对第7天穿过平台次数和逗留平台象限时间有交互作用(F值分别为4.67、5.68,P<0.05或<0.01).3个月时,高氟组大鼠逃避潜伏期时间[(14.71±4.85)s]较对照组[(9.28±4.22)s]明显增加(P<0.05);6个月时,低氟组、高氟组大鼠逃避潜伏期时间[(12.42±8.03)、(17.48±8.05)s]较对照组[(7.04±3.29)s]延长(P均<0.05),高氟组第7天穿过平台次数[(1.62±0.87)次]和逗留平台象限时间[(16.70±5.02)s]较对照组[(3.53±1.67)次、(23.33±5.35)s]降低(P均<0.05).染氟剂量对乙酰胆碱酯酶与丁酰胆碱酯酶活性均有明显影响(F值分别为12.83、13.27,P均<0.01);染氟时间对丁酰胆碱酯酶活性有明显影响(F=16.26,P<0.01).3个月时,低氟组丁酰胆碱酯酶活性[(0.55±0.12)kU/g]明显低于对照组[(0.73±0.10)kU/g,P<0.05],高氟组乙酰胆碱酯酶[(0.62±0.42)kU/g]和丁酰胆碱酯酶活性[(0.58±0.10)kU/g]均明显低于对照组[(1.41±0.52)、(0.73±0.10)kU/g,P均<0.05].胆碱酯酶活性与逃避潜伏期时间呈负相关(r=-0.68,P<0.01),胆碱酯酶活性与逗留平台象限时间呈正相关(r=0.57,P<0.01).结论 燃煤污染型慢性氟中毒大鼠学习记忆能力减退,可能与脑组织胆碱酯酶活性下降有关,二者间有量效关系.     

骨桥蛋白在不同营养条件下氟中毒大鼠肝组织中的表达及意义

目的探讨骨桥蛋白（OPN）在氟中毒大鼠肝组织中的表达及其意义。方法通过给予48只Wistar大鼠不同钙营养状况、不同蛋白营养状况和投氟剂量的固体饲料,复制氟中毒大鼠模型,6个月后提取各组大鼠肝组织,应用免疫组化技术及RT-PCR技术检测OPN的表达水平。结果大鼠肝脏OPNmRNA表达及蛋白平均表达水随着大鼠骨氟含量的增加而依次增强。结论氟可促进大鼠肝组织OPN表达,并且过量氟和低钙、低蛋白对促进大鼠肝组织OPN表达具有协同作用,而且OPN的表达与氟中毒机体损伤的程度密切相关。     

HepG2细胞电转染条件的优化

目的优化HepG2细胞电转染条件,进一步提高HepG2细胞的转染效率。方法采用电穿孔方法将pcDNA3．1-EGFP导入HepG2细胞中,在500μL电转染体系中,在不同电场强度、细胞数目、脉冲频率、脉冲时间、电转质粒数目、电转缓冲液、培养基血清浓度条件下,分别将pcDNA3．1-EGFP质粒电转染HepG2细胞,检测不同条件下细胞存活率和转染率。结果电转前4℃孵育电转体系混合液10min,方波电转条件在1个电脉冲、电压270V、细胞数为2×10^6个、质粒20μg、脉冲时间20ms、电转缓冲液为优化缓冲液、电转后置于37℃、含15％FBS的DMEM高糖培养基中培养48h,可获得高转染率（60．68±1．87）％。结论优化电穿孔法的电转染条件能够有效提高HepG2细胞的电转染效率。本研究为外源基因电转染HepG2细胞提供了可靠的试验参数。     

非痴呆性血管性认知功能障碍患者ChAT和CHE活性变化及其临床意义

目的通过检测非痴呆性血管性认知功能障碍(VCIND)患者血胆碱乙酰转移酶(ChAT)及胆碱酯酶(CHE)活性的变化,初步探讨VCIND的发生机制。方法选择61例VCIND患者作为研究组,其检测符合Rockwood认知功能障碍诊断标准但未达到NINDS-ARIIEN血管性痴呆诊断标准。同期相匹配的75例健康者作为对照组,两组均清晨空腹抽取静脉血并分离血清。应用分光光度法检测血清ChAT及CHE活性。结果血管性认知功能障碍组ChAT活性(120.94±23.93)U/mL较对照组(64.88±12.23)U/mL明显增高,差异有统计学意义(P<0.01),CHE活性两组相比差异无统计学意义(P>0.05)。结论 VCIND患者血清ChAT活性增加,促进乙酰胆碱的合成,可能是VCIND患者机体维持认知功能的一种代偿作用。     

灯盏乙素对痴呆大鼠脑组织乙酰胆碱尼古丁受体蛋白及mRNA表达的作用

目的:观察灯盏乙素对痴呆模型大鼠乙酰胆碱尼古丁受体(nAChR)亚单位蛋白质和mRNA水平表达的影响,探讨其可能的作用机制。方法:Wistar大鼠42只,随机分为5组,正常对照组(6只)、假手术组(6只)、学习记忆损伤模型组(6只)、灯盏乙素处理组(10只)和脑复康处理组(10只)。用双侧脑室注射β淀粉样蛋白     

燃煤型氟中毒大鼠脑组织神经型尼古丁受体mRNA及蛋白表达水平改变

目的 观察燃煤型氟中毒大鼠学习记忆能力变化,测定大鼠脑组织神经型尼古丁受体(nAChR)mRNA和蛋白表达水平,探讨大鼠学习记忆能力改变的发生机制.方法 健康SD大鼠24只,体质量100～120 g,按体质量随机分为3组,每组8只.对照组饲以常规饲料,低氟组和高氟组以燃煤型氟中毒重病区燃煤烘烤的当地玉米为主要饲料(含氟量分别为11.30、104.20 mg/kg)来复制慢性氟中毒大鼠模型,染氟时间为6个月.染氟结束后,用Morris水迷宫方法检测大鼠行为学变化,处死动物取脑,用匀浆-氟离子选择电极法测定脑组织含氟量,实时荧光定量PCR法检测nAChR mRNA水平,蛋白印迹法测定nAChR蛋白表达水平.结果 低氟组和高氟组大鼠逃避潜伏期时间[(12.42±8.03)、(17.48±8.05)s]较对照组[(7.04±3.29)s]显著延长(P均<0.05),高氟组第7天穿过平台次数[(1.62±0.87)次]和逗留平台象限时间[(16.70±5.02)s]较对照组[(3.53±1.67)次、(23.33±5.35)s]降低(P均<0.05).低氟组和高氟组大鼠脑组织含氟量[(1.14±0.04)、(1.79±0.04)mg/kg]显著高于对照组[(0.52±0.05)mg/kg,P均<0.05],且高氟组大鼠脑组织含氟量高于低氟组(P<0.05).高氟组大鼠脑组织nAChR α3、α4、α7亚单位mRNA水平(1.51±0.20、1.45±0.06、1.63±0.08)较对照组(1.79±0.11、1.66±0.14、1.83±0.06)显著降低(P均<0.05),而低氟组(1.65±0.17、1.59±0.09、1.71±0.03)与对照组比较无明显改变(P均>0.05).低氟组和高氟组大鼠脑组织nAChR α3、α4、α7亚单位蛋白表达水平(0.58±0.13、0.16±0.03、1.41±0.38和0.56±0.23、0.08±0.02、0.51±0.16)较对照组(1.48±0.42、0.57±0.21、2.56±0.26)显著降低(P<0.05或<0.01).结论 燃煤型氟中毒大鼠学习记忆能力降低可能与脑组织nAChR蛋白表达及mRNA水平降低有关,nAChR表达改变可能是引起动物学习记忆能力降低的主要机制.

Abstract：

Objective To observe the learning and memory changes in coal-burning type of fluorosis rats, detect the expressions of neuronal nicotinic acetylcholine receptor(nAChR) at mRNA and protein levels in rat brains and to reveal the mechanism of changed learning and memory ability. Methods Twenty-four healthy SD rats, weighting 100 - 120 g, were randomly divided into three groups(8 in each). Control group was fed with normal diet, and low- and high-dose fluoride groups were fed with corn polluted with high fluoride (fluoride were 11.30,104.20 mg/kg, respectively) during drying processes with local burning-coal from the areas of endemic fluorosis to established rat model of chronic fluorosis. After exposed to fluoride for 6 months, behavioral changes were measured by Morris water maze. Animals were sacrificed, the brain was taken, after homogenizing the fluoride content of brain tissue was determined by fluoride ion selective electrode. The α3, α4 and α7 nAChR subunits at mRNA and protein levels were analyzed by real-time PCR and Western blotting, respectively. Results For rats in low- and high-fluoride groups, the escape latency time[(12.42 ± 8.03),(17.48 ± 8.05)s] was significantly longer than that in the control[(7.04 ± 3.29)s, all P< 0.05]. For rats in high-fluoride group, the numbers of crossing the platforms (1.62 ± 0.87) and the time of staying at the platforms[(16.70 ± 5.02)s] were significantly decreased as compared to that of control[3.53 ± 1.67, (23.33 ± 5.35)s, all P < 0.05]. The fluoride content in rat brain tissue in low- or high-fluoride groups [(1.14 ± 0.04), (1.79 ± 0.04)mg/kg] was significantly higher than that of control [ (0.52 ± 0.05) mg/kg, all P < 0.05]; in addition, the amount of fluoride in brain tissue of high-fluoride group was significantly higher than that of low-fluoride group(P < 0.05). In high-fluoride group, the mRNA expressions of α3, α4 and α7 nAChR subunits in rat brains(1.51 ± 0.20,1.45 ± 0.06,1.63 ± 0.08) were significantly lower as compared to controls (1.79 ± 0.11,1.66 ± 0.14,1.83 ± 0.06, all P< 0.05); whereas there were no significant changes in mRNA levels of these receptor subunits of the rat brains between low-fluoride group(1.65 ± 0.17,1.59 ± 0.09,1.71 ± 0.03) and controls (all P > 0.05). Furthermore, the protein levels of α3, α4 and α7 nAChR subunits in rat brains of highfluoride group(0.58 ± 0.13,0.16 ± 0.03,1.41 ± 0.38) and low-fluoride group(0.56 ± 0.23,0.08 ± 0.02,0.51 ± 0.16) were significantly lower than those of controls( 1.48 ± 0.42,0.57 ± 0.21,2.56 ± 0.26, P<0.05 or < 0.01). Conclusions Decreased ability of learning and memory in coal-burning type of fluorosis rats may be associated with declined expressions of nAChR at proteins and mRNA levels, which might be the main mechanism of the behavior change.     

氟中毒对大鼠脑组织Ras-Erk1/2通路及转录因子CREB的影响

目的研究慢性氟中毒大鼠脑组织中细胞外信号调节蛋白激酶（Extracellular signal regulated kinases,Ras-Erk1/2）通路主要激酶表达变化及其对转录因子环一磷酸腺苷反应单元结合蛋白（cAMP Responsive Element Binding Protein,CREB）的影响。方法 SD（Sprague dawley）大鼠随机分为3组,即正常组、饮水中小剂量加氟（5 mg/L）组、大剂量加氟（50 mg/L）组,实验期为6个月。实验结束时,用氟离子选择电极法测定大鼠尿氟及血氟含量,尼氏染色检查神经细胞尼氏小体改变,蛋白印迹（Western-blotting）方法检测脑组织中小鸟苷三磷酸结合蛋白（small GTP-binding protein,Ras）、Erk1/2、CREB信号转导激酶的蛋白表达水平,实时荧光定量聚合酶链式反应（Real-time Polymerase Chain Reaction,Re-al-time PCR）方法检测c-fos基因mRNA表达水平。结果与对照组相比,染氟组大鼠有不同程度的氟斑牙及血氟尿氟升高;大脑皮质和海马部位神经细胞尼氏小体减少;脑组织中Ras、phospho-Erk1/2t、otal-Erk1/2及phospho-CREB蛋白表达水平上升（F值分别为19.9、114.59、4.6 9、7.6,P〈0.05）,以大剂量染氟组尤为明显t,otal-CREB在各组间未见明显改变;大剂量染氟组c-fos基因mRNA表达明显升高,而小剂量染氟组该基因mRNA表达降低。结论过多的氟可引起大鼠脑组织神经细胞损伤,脑组织中Ras-Erk1/2信号激酶通路过度激活可刺激转录因子CREB磷酸化,从而影响c-fos基因的表达,该过程可能参与慢性氟中毒脑损伤机制。     

慢性氟中毒大鼠脑组织中c-Jun氨基末端激酶表达水平观察

[摘要]目的：观察慢性氟中毒大鼠脑组织中c-Jun氨基末端激酶（JNK）信号转导激酶表达变化,进一步揭示慢性氟中毒神经损伤的分子机制。方法：SD大鼠随机分为3组：对照组、低氟组、高氟组,每组24只,