低剂量长期砷暴露对HaCat细胞增殖及凋亡水平的影响

目的探讨低剂量长期砷暴露对HaCat细胞增殖及凋亡水平的影响。方法 HaCat细胞暴露于浓度为0、0.05、0.10μmol/L的NaAsO215周后,用直接细胞计数法计数对照组及染砷组细胞数,检测细胞增殖水平;用流式细胞仪测定10 000个细胞的细胞凋亡发生水平。结果各染砷组细胞增殖速率与对照组相比均显著增高(P<0.05),且0.10μmol/L组细胞增殖率(245.00±8.66)%显著高于0.05μmol/L组(165.00±15.00)%(P<0.05),细胞增殖水平与染砷剂量间呈显著剂量-效应关系;0.05μmol/L组(0.28±0.08)%及0.10μmol/L组(0.34±0.09)%细胞凋亡率均明显低于对照组(0.74±0.18)%(P<0.05)。结论长期低剂量砷暴露可使HaCat细胞的增殖能力明显增强,并诱导细胞凋亡率显著降低。     

tBHQ对NaAsO2诱导HaCaT细胞凋亡的拮抗作用

目的探讨叔丁基对苯二酚(tertiary butylhydroquinone,tBHQ)对亚砷酸钠(NaAsO2,sodium arsenite)诱导人角质上皮HaCaT细胞凋亡的拮抗作用。方法 tBHQ(10、25、50μmol/L)预处理12 h,再与NaAsO2(5、10、30μmol/L)共同处理HaCaT细胞24 h。用Annxin V/PI染色流式细胞术法检测细胞凋亡率;DAPI染色观察细胞形态学改变;JC-1法测定线粒体膜电位。结果将实验数据进行ANOVA分析处理后表明,5,10、30μmol/L NaAsO2单独作用时,细胞凋亡率与对照组相比显著升高,而线粒体膜电位则显著下降(P<0.05或P<0.01),形态学观察可见高强度DAPI染色细胞数目增加和凋亡小体出现;当给予tBHQ(10、25、50μmol/L)预处理后,NaAsO2致HaCaT细胞凋亡率升高和线粒体膜电位下降均明显受到抑制(P<0.05),形态学观察可见高强度DAPI染色细胞数目和细胞核碎片明显减少。结论实验结果表明tBHQ可能通过线粒体凋亡途径抑制NaAsO2引起的HaCaT细胞凋亡。     

姜黄素干预对慢性饮水砷暴露小鼠肝脏Nrf2信号通路的影响

目的观察姜黄素干预对慢性饮水砷暴露小鼠肝脏核转录因子Nrf2信号通路的影响。方法实验小鼠自由饮用不同浓度亚砷酸钠(NaAsO2,10、50、100 mg/L)6周,再分别给予姜黄素灌胃干预(200 mg/kg和600 mg/kg,每周2次),采用Western blotting和免疫组化技术分别检测肝脏Nrf2、NQO1和HO-1的蛋白表达水平及Nrf2的细胞定位。结果与单纯砷染毒组相比,姜黄素干预组的肝脏Nrf2、NQO1和HO-1蛋白表达均显著增高,同时肝脏细胞的胞浆和胞核中棕褐色阳性颗粒均显著增多,且Nrf2明显入核增多。结论姜黄素干预能诱导饮水砷暴露小鼠肝脏Nrf2蛋白活化,并进一步激活Nrf2下游信号通路。     

吸烟、饮酒对饮水型砷暴露人群砷中毒发病风险及砷甲基化代谢能力的影响

目的 探究在砷污染的山西内蒙地区吸烟、饮酒等因素是否增加砷中毒发病风险及影响砷甲基化的代谢.方法 2017年8月至2017年10月对848位受试者进行了问卷调查和尿样检测,通过描述性分析,以探究砷中毒危险因素及吸烟饮酒对砷甲基化代谢的影响.结果 砷中毒患者161人,占18.99％;多因素logistic回归分析结果表明...     

吸烟与饮酒对不同浓度饮水型砷暴露人群尿砷代谢模式的影响

目的 探讨吸烟、饮酒对砷暴露人群尿砷代谢的影响.方法 2008年选择山西省高砷地区不同饮水砷浓度暴露的年龄≥18岁的成年人作为调查对象,根据饮水砷浓度将调查对象分为3组:高砷暴露组(饮水砷浓度≥0.05 mg/L),低砷暴露组(0.01 mg/L≤饮水砷浓度＜0.05 mg/L),对照组(饮水砷浓度＜0.01mg/L).排除近期食用过海产品以及有慢性饮水型砷中毒症状的人群,通过问卷调查方式确定吸烟、饮酒的情况,同时采集居民家水样,以及调查对象的即时尿样.采用氢化物发生原子吸收分光光度法检测尿中无机砷(iAs)、一甲基砷(MMA)和二甲基砷(DMA)含量.以iAs、MMA及DMA的总和表示总砷(tAs)水平;以iAs/tAs、MMA/tAs和DMA/tAs分别计算iAs％、MMA％、DMA％;以(MMA+ DMA)/tAs及DMA/(MMA+ DMA)分别计算一甲基化率(FMR)和二甲基化率(SMR)水平.结果 共调查395人,高砷暴露组中烟酒嗜好者MMA％(16.24％)高于无烟酒嗜好者(12.16％),烟酒嗜好者的SMR水平(82.19％)低于无烟酒嗜好者(86.13％),差异有统计学意义(P均＜ 0.05),吸烟者、饮酒者与无烟酒嗜好者相比,各评价指标差异无统计学意义(P＞0.05);在低砷暴露组中吸烟者、烟酒嗜好者的MMA％( 13.86％、13.99％)均高于无烟酒嗜好者(11.83％),吸烟者、烟酒嗜好者的DMA％(72.87％、77.76％)和SMR水平(83.48％、83.90％)均低于无烟酒嗜好者(80.35％、86.54％),差异有统计学意义(P均＜0.05),饮酒者与无烟酒嗜好者相比,各评价指标差异无统计学意义(P＞0.05).对照组人群中吸烟者、烟酒嗜好者的MMA％( 17.27％、17.06％)均高于无烟酒嗜好者(11.52％),吸烟者、烟酒嗜好者的DMA％(73.89％、72.29％)和SMR水平(81.48％、82.58％)均低于无烟酒嗜好者(79.68％、87.19％),差异有统计学意义(P均＜ 0.05),饮酒者与无烟酒嗜好者相比,各评价指标差异无统计学意义(P＞0.05).结论 在不同浓度砷暴露的情况下,吸烟饮酒人群对砷的甲基化能力低于非吸烟饮酒人群.     

饮水型砷暴露人群DNA氧化损伤与砷甲基化模式分析

目的 探讨高砷暴露人群DNA氧化损伤和砷甲基化模式的关系.方法 对饮水型砷暴露人群进行横断面调查,用超低温捕集-氢化物发生-原子吸收分光光度法分析尿无机砷(iAs)、一甲基砷(MMA)和二甲基砷(DMA)水平,以酶联免疫法测定尿8-羟基脱氧鸟苷(8-OHdG)含量.结果 与低砷暴露组相比,高砷暴露人群尿中各形态砷与总砷水平、iAs%和MMA%升高,DMA%、一甲基化率(FMR)和二甲基化率(sMR)降低,且差异显著(P<0.01);高砷暴露人群尿8-OHdG含量是低暴露人群的2.3倍(P<0.01);高砷暴露者尿8-OHdG含量与尿形态砷、总砷和MMA%呈显著正相关,与SMR呈显著负相关.结论 高砷暴露导致人体DNA氧化损伤与砷甲基化能力降低,两者可能存在联系.     

饮水砷暴露小鼠肝和脑组织多形态砷检测分析

目的观察饮用含不同质量浓度和不同形态的无机砷(iAsⅢ,iAsⅤ)水,砷化物在小鼠肝和脑组织中的分布及代谢情况。方法小鼠以自由饮水方式暴露iAsⅢ或iAsⅤ42d,采用氢化物发生-超低温捕集-原子吸收分光光度法,测定小鼠肝和脑组织中无机砷(iAs)、一甲基胂(MA)、二甲基胂(DMA)和三甲基胂(TMA)水平。结果在小鼠肝组织中,iAs、MA及DMA均随染砷量的增加而升高;在脑组织中,iAs在各染砷组与对照组之间,差异无统计学意义。DMA在各染砷组中随染砷剂量的增加而升高,但脑组织中未检测到MA。结论经饮水进入小鼠体内的iAsⅢ或iAsⅤ,主要在肝组织内进行甲基化代谢,低质量浓度的iAsⅢ较iAsⅤ更容易进入肝组织,并被甲基化代谢。砷化物可以透过成鼠的血脑屏障,脑组织分布的砷化物形态以DMA为主。     

急性白血病P~(15)基因异常及甲基化研究

用聚合酶链反应 (PCR)方法扩增 P1 5基因外显子 1,再用限制性内切酶 - PCR方法检测 P1 5基因甲基化。结果 48例患者中 P1 5基因失活者共 2 7例 (5 8.92 % ) ,AL L2 1例中有 12例 (5 7.41% ) ,ANL L2 7例中 15例(5 5 .5 6 % )。 P1 5 基因以甲基化失活为主。 P1 5 Cp G岛甲基化在各型急性白血病中均有很高的发生率 ,可以作为各型急性白血病通用的微量残留病 (MRD)指标 ;白血病缓解期 P1 5 Cp G岛甲基化仍为阳性可能预示着复发。认为 P1 5基因失活的检测对于探讨急性白血病的发病机制、判断预后有重要意义     

亚慢性砷暴露小鼠血和肝中砷形态及谷胱甘肽水平检测分析

目的 探讨亚慢性饮水砷暴露小鼠血和肝中砷形态的分布,评价砷对血和肝中还原型谷胱甘肽(GSH)水平的影响.方法 小鼠以自由饮水方式饮用含砷量为0(对照)、25、50、100mg/L的水溶液,连续染砷6周.采用氢化物发生-超低温捕集-原子吸收分光光度法,检测小鼠血和肝中无机砷(iAs)、一甲基砷酸(MMA)和二甲基砷酸(DMA)的水平,计算甲基化率.采用二硫双硝基苯甲酸(DTNB)法测定全血和肝组织中GSH的水平.结果 小鼠血和肝中iAs、MMA和DMA水平随染砷剂量的增加而升高.各染砷组小鼠血和肝中的砷一甲基化率(PMI)和二甲基化率(SMI)与对照组比较差异均有统计学意义(P＜0.05),其中50 mg/L染砷组小鼠肝中SMI[(50.45±2.94)%]明显高于25 mg/L组[(41.68±7.09)%]和100 mg/L组[(41.19±8.87)%],组间比较差异有统计学意义(P＜0.05).各染砷组小鼠血和肝中砷形态的构成比(iAs:MMA:DMA)分别为2:3:5和4:3:3.有机砷(MMA+DMA)的水平分别约占总砷的80%和60%.各染砷组小鼠血和肝中GSH水平随染砷剂量的增加而下降,与对照组比较差异均有统计学意义(P＜0.05),但各染砷组之间的小鼠血和肝中GSH水平比较差异均无统计学意义(P＞0.05).结论 当砷暴露水平达到一定程度后,肝脏对iAs的甲基化代谢能力可达到饱和.血中砷形态变化不同于肝组织,提示机体内的其他组织器官也可能具有砷甲基化代谢能力.血和肝中GSH水平是反映砷毒性的较好指标.     

探讨2型糖尿病患者检测尿微量白蛋白的意义

对182例T2DM进行MA的检测,并与50例健康人进行比较.结果与对照组比有显著性(P＜0.01);T2DM检出阳性率为36.26%,对照组为0%.结论 MA可作为T2DM患者的常规检查.     

慢性砷暴露对小鼠动情周期的影响

目的探讨慢性砷暴露的雌激素样效应。方法采用宫颈黏液结晶法对不同浓度慢性砷暴露小鼠动情周期和动情期进行检查。结果不同浓度的三氧化二砷均使小鼠动情周期和动情期发生紊乱,但与对照组无显著差异（P〉0．05）,也无明显规律（或缩短、或延长）,尤其是动情期。结论动情周期的紊乱是反应性激素代谢失调的敏感指标,本研究初步证明砷具有影响机体内分泌的作用,当属环境内分泌干扰物。     

牛磺酸对砷暴露小鼠肾组织核酸损伤的保护作用

目的 观察牛磺酸对砷暴露小鼠肾组织核酸损伤的保护作用。方法 昆明种小鼠40只，随机分为3组：4mg/L三氧化二砷染毒组、150m异／kg牛磺酸拈抗组以及生理盐水对照组。连续染毒60d，取小鼠肾组织固定，用免疫组织化学方法观察肾组织细胞8-硝基鸟嘌呤（8-NO2-G）的表达。结果 染砷组小鼠肾细胞出现肿胀，胞浆内有空泡变性，部分胞质溶解，核肿胀、溶解等明显的病理学变化。牛磺酸拮抗组小鼠肾组织的病理变化相对较轻。小鼠肾皮质细胞的胞浆中8-NO2-G吸光度值，染砷组（0．043±0．014）明显高于对照组（0．004±0．002），差异有统计学意义（P〈0．01）；牛磺酸拮抗组（0．016±0．013），低于染砷组（P〈0．05），但仍明显高于对照组（P〈0．05）。结论 牛磺酸对砷暴露小鼠肾组织核酸损伤具有保护作用。     

HO-1 mRNA在砷暴露肝损伤小鼠肝组织中的表达

目的:探讨血红素氧化酶-1 mRNA(HO-1mRNA)在砷暴露肝损伤小鼠肝组织中表达的意义.方法:40R♂小鼠被随机分成对照组和亚砷酸钠组(iAs3 组).10 mo后处死小鼠,肝功能检查血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)、球蛋白(GLB);部分肝组织作HE染色观察病理变化;TRIzol-酚-氯仿一步法提取肝组织总RNA,紫外分光光度法测定总RNA及纯度,实时荧光定量PCR法测定肝组织中HO-1 mRNA的表达,以18S基因作为质控.结果:iA3 组小鼠血清ALT、AST、GLB值高于对照组(61.5±5.5 U/L V5 38.0±5.6 U/L,530.9±39.0 U/L vs 118.3±9.1 U/L.27.15±4.1g/L vs 20.9±0.6 edL,均P<0.05);肝组织病理检查有明显的炎症细胞浸润和肝细胞坏死,纤维组织增生;小鼠肝组织HO-1 mRNA基因表达在iAs3 组增高,与对照组比较有统计学意义(t=5.393,P<0.05).结论:小鼠亚砷酸钠长期暴露诱导的HO-1高表达,可能参与了肝损伤肝纤维化发生机制.     

氟砷污染对暴露人群骨代谢的影响

目的 探讨氟和砷对暴露人群骨代谢的影响.方法 2006年选择贵州省兴仁县雨樟镇交乐村152例氟砷联合暴露者以及位于交乐村约13 km无高氟高砷暴露史59例对照作为研究对象.分别检测尿氟、尿砷及骨代谢效应指标尿羟脯氨酸(UHYP)和尿Ⅰ型胶原交联氨基末端肽(UNTX)、骨强度指数(STI).结果 氟对UHYP、UNTX的主效应均有统计学意义(F=9.785、4.225,P均<0.01),对STI的主效应无统计学意义(F=0.183,P>0.05).砷对UNTX的主效应有统计学意义(F=2.660,P<0.05),对UHYP、STI的主效应无统计学意义(F=2.012、0.183,P均>0.05).氟、砷的交互作用对UNTX有统计学意义(F=2.429,P<0.01),但氟、砷交互作用对UHYP和STI无统计学意义(F=1.218、1.001,P均>0.05).结论 氟可影响胶原代谢及骨吸收,砷主要影响骨吸收.氟砷混合暴露时对骨吸收影响较显著.对氟、砷暴露人群进行健康监测时,UNTX可作为评价氟砷污染致暴露人群骨代谢交互作用的生物学标志.

Abstract：

Objective To explore the effect of fluoride and arsenic pollution on bone metabolism in exposed population. Methods One hundred and fifty-two fluoride and arsenic exposed people were selected from Jiaole village, Yuzhang town, Xingron county, Guizhou province in 2006, and 59 not exposed people from Daguoduo village 13 km away from Jiaole village were selected as control. Urinary fluorine(UF), urinary arsenic (UAs), urinary hydroxyproline (UHYP), cross-linked N-telopeptides of type I collagen (UNTX) and bone strength index(STI) were detected. Results The main effect of fluoride on UHYP and UNTX were statistically significant (F = 9.785, 4.225, P < 0.01 ), but was not significant on STI(F = 0.183, P > 0.05). The main effect of arsenic on UNTX was statistically significant (F = 2.660, P < 0.05 ), but was not significant on UHYP and STI(F = 2.012, 0.183,all P > 0.05). The interaction between fluoride and arsenic on UNTX was statistically significant (F= 2.429, P <0.01), but was not significant on UHYP and STI(F= 1.218, 1.001, all P> 0.05). Conclusions Fluoride exposure can affect the metabolism of collagen and bone resorption, and Arsenic exposure main affect bone resorption, fluoride and arsenic co-exposure have more significant effect on bone resorption. UNTX may be used as biological biomarker of bone metabolism for population co-exposed to fluoride and arsenic in health monitoring.     

基质金属蛋白抑制因子-1 mRNA在饮水砷暴露肝损伤小鼠肝组织中的表达

目的 探讨基质金属蛋白酶抑制因子-1(TIMP-1)mRNA在饮水砷暴露肝损伤小鼠肝组织中的表达及意义.方法 50只雄性小鼠被随机分成对照组、亚砷酸钠组(iAs3+组,300 mg/L)、砷酸钠组(iAs5+组,300 mg/L).10个月后处死小鼠,肝功能检查血清丙氨酸转氨酶(ALT)、天门冬氨酸氨基转移酶(AST)、球蛋白(GLB);部分肝组织进行HE染色;Trizol-酚-氯仿一步法提取小鼠肝组织总RNA,紫外分光光度法测定总RNA及纯度,实时荧光定量PCR法测定肝组织中TIMP-1 mRNA的表达,以18S基因作为质控.结果 ALT在对照组(36.67±3.51)、iAs3+组(61.46±13.85)和iAs5+组(43.31±4.21)组间比较差异有统计学意义(F=6.559,P＜0.05);iAs3+组与对照组比较差异有统计学意义(P＜0.05),iAs5+组与对照组、iAs3+组比较差异无统计学意义(P＞0.05);AST在对照组(135.00±20.42)、iAs3+组(510.86±59.01)和iAs5+组(258.93±22.40)组间比较差异有统计学意义(F=83.327,P＜0.05);GLB在对照组(20.86±0.61)、iAs3+组(26.94±3.73)和iAs5+组(24.59±5.27)组间比较差异无统计学意义(F=2.800,P＞0.05).肝组织病理检查显示,肝组织中有明显的肝细胞坏死和再生,TIMP-1 mRNA表达组间比较差异有统计学意义(F=17.337,P＜0.05).结论 TIMP-1基因在水砷暴露肝损伤小鼠肝组织损伤、肝纤维化形成过程中可能起重要作用.     

Urinary arsenic speciation profiles in mice subchronically exposed to low concentrations of sodium arsenate in drinking water

Arsenic is a proven human carcinogen. Although the mechanism of its carcinogenicity is still largely unknown, methylation is thought to have an important role to play in arsenic toxicity. In this study, urinary methylation profiles were investigated in female C57BL/6J black mice given drinking water containing 500 μg arsenate (As(V))/L, 250 μg As(V)/L, or 100 μg As(V)/L as sodium arsenate for 2 months. The concentrations of arsenic chosen reflected those in the drinking water often encountered in arsenic-endemic areas. Urine samples were collected from the mice at the end of the exposure period, and the arsenic species were analyzed by high performance liquid chromatography-inductively coupled plasma-mass spectrometry. All detectable arsenic species showed strong linear correlation with the administered dosage. The methylation patterns were similar in all three groups with a slight decrease of dimethylarsinic acid/As(V) ratio in the 500-μg/L group, which corresponded to the significantly higher arsenic retention in the tissue. The results indicate that urinary arsenic could be used as a good biomarker for internal dose and potential biological effects. Different doses of arsenic exposure could result in different degrees of methylation, excretion, and tissue retention, and this may contribute to the understanding of arsenic carcinogenicity.     

Vascular hyperpermeability in response to inflammatory mustard oil is mediated by Rho kinase in mice systemically exposed to arsenic

The mechanisms underlying vascular dysfunction and cardiovascular disease induced by chronic arsenic exposure are not completely understood. We have previously shown that mice chronically fed sodium arsenite are hypersensitive to the permeability-increasing effects of inflammatory mustard oil. The aim of this study was to investigate whether RhoA/Rho kinase (ROCK)-mediated vascular leakage (hyperpermeability) is induced by mustard oil in mice systemically exposed to arsenic.Animals were orally fed water (control group) or sodium arsenite for 8 weeks. We compared the blood pressure and microvessel density of the ears between these two groups. Both control and arsenic groups exhibited a similar mean arterial pressure and microvessel density. Microvessel permeability changes that occurred following mustard oil treatment in the presence of Y-27632, a ROCK inhibitor, were quantified using the Evans blue (EB) technique and vascular labeling with carbon particles. Both the excessive leakiness of EB and the high density of carbon-labeled microvessels upon stimulation with mustard oil in the arsenic-fed mice were reduced by Y-27632 treatment. However, RhoA and ROCK2 expression levels were similar between control and arsenic-fed mice. We further investigated ROCK2 levels and ROCK activity in the ears following mustard oil challenge. ROCK2 levels in mouse ears treated with mustard oil were higher in the arsenic group as compared with the control group. Following mustard oil application, ROCK activity was significantly higher in the arsenic-fed mice compared with the control mice. These findings indicate that increased ROCK2 levels and enhanced ROCK activity are responsible for mustard oil-induced vascular hyperpermeability in arsenic-fed mice.     

Gender comparisons of control of breathing and metabolism in conscious mice exposed to cold

We evaluated the effects of 2 h of warm (24 degrees C) and cold (6 degrees C) exposure on metabolism and ventilation (V(E)) in conscious male and female Harlan ICR Swiss Webster mice exposed to air, and 8% O(2) in N(2) (hypoxia) and to 5% CO(2) in O(2) (hypercapnia) for 2 min each at both temperatures. All cold-exposed mice increased O(2) consumption (V(O2)), and maintained body temperature. Cold-exposed females doubled their tidal volume, increased their V(E) fivefold, and doubled their ventilatory equivalent to V(O2) (V(E)/V(O2)). In contrast, cold-exposed males decreased tidal volume and doubled V(E) relative to warm exposure. The ventilatory equivalent of males was similar during warm and cold exposure. During warm exposure, mice of both genders increased their ventilatory responses to both hypoxia and to hypercapnia by different mechanisms. In contrast, during cold exposure, these responses were blunted relative to air measurements in females and decreased below air values in males. Thus, cold exposure was able to elicit gender-specific ventilatory and metabolic responses.