兴奋性氨基酸递质系统在乐果诱导星形胶质细胞活化中的作用

Objective To study the involvement of excitatory amino acid system in astrocytes activation caused by dimethoate. Methods Pure-cultured astrocytes were gained by three passages from primary cultured rat nerve cells, then treated with 10-6,10-5,10-4 mol/L dimethoate for 48 h, 50 μmol/L and 100μmol/L MK801, a NMDA receptor blocker, was used to intervene the effects induced by 10-4 mol/L dimethoate.HPLC-FLD was utilized to measure the concentrations of excitatory amino acid (EAA), RT-PCR was used to detect the expression levels of NR2B, GLT-1, GLAST, GFAP and S100β mRNA, and immunofluresence staining method was applied to measure the expression levels of GFAP and S100β proteins. Results The expression levels of GLAST mRNA in all exposure groups were 67.8% ,68.6% and 76.2% of control level,respectively, which were significantly lower than that of control group (P＜0.05); The concentrations of EAA significantly decreased in 10-4 mol/L dimethoate group, as compared with control group (P＜0.01); the expression levels of GFAP mRNA in 10-4 mol/L dimethoate group, of S100β mRNA in 10-5 mol/L dimethoate group, of GFAP protein in 10-4 mol/L and 10-5 mol/L dimethoate groups and S100β protein in 10-4 mol/L dimethoate group were significantly higher than those in control group (P＜0.01). The expression levels of GLT-1 and GLAST mRNA in 10-4 mol/L dimethoate plus 50 μ mol/L or 100 μ mol/L MK801 groups increased significantly, as compared with 10-4 mol/L dimethoate group (P＜0.01), the expression levels of NR2B mRNA in 10-4 mol/L dimethoate plus 50 μ mol/L or 100 μmol/L MK801 groups increased significantly, as compared with control group (P＜0.05 or P＜0.01); the concentration of Glu in 10-4 mol/L dimethoate plus 100 μ mol/L MK801 group increased significantly, as compared with 10-4 mol/L dimethoate group (P＜0.01); the expression levels of GFAP mRNA and protein in10-4 mol/L dimethoate plus 50 μ mol/L or 100 μ mol/L MK801 groups decreased significantly (P＜0.01); S100β protein expression level in 50 μ mol/L MK801 intervention group was significantly higher than thatl in control group (P＜0.01). Conclusion Excitatory amino acid system involved in astrocytes activation caused by dimethoate. MK801 was useful to control astrocytes gliosis.     

过氯酸铵对大鼠甲状腺功能及其球蛋白和过氧化物酶mRNA表达的影响

目的 研究过氯酸铵(AP)对大鼠甲状腺功能及甲状腺球蛋白(Tg)、甲状腺过氧化物酶(TPO)基因mRNA表达的影响.方法 将雄性SD大鼠30只随机分为:正常对照组、低碘组(含碘量:50μg/kg)、AP染毒低(130 mg/kg)、中(260 mg/kg)、高剂量组(520 mg/kg)及AP+高碘组[AP:520 mg/kg,高碘饮水(10 mg/L)],每组5只.经口染毒90 d后处死,放射免疫法测定血清游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)及促甲状腺激素(TSH)的水平;荧光定量PCR法测定甲状腺球蛋白(Tg)、甲状腺过氧化物酶(TPO)基因mRNA表达水平.结果 AP中剂量和AP高剂量组FT4水平[(9.540±1.327)fmol/ml,(6.509±1.949)fmol/ml)明显低于正常对照组[(13.505±1.276)fmol/ml],差异有统计学意义(P＜0.05,P＜0.01).AP高剂量组的TSH水平[(1.227±0.295)mIU/L]明显高于正常对照组[(0.545±0.282)mIU/L],差异有统计学意义(P＜0.05);各AP剂量组Tg的mRNA表达相对值均明显低于正常对照组,差异有统计学意义(P＜0.01),AP高剂量组TPO基因mRNA表达相对值明显低于正常对照组,差异有统计学意义(P＜0.05).结论 AP可降低大鼠FT3、FT4水平,引起TSH反馈性增高,并明显抑制Tg和TPO基因mRNA的表达;而高碘可以在一定程度上拮抗AP对大鼠甲状腺的毒作用.

Abstract：

Objective To investigate the effects of ammonium perchlorate (AP) on thyroid functions and mRNA expression levels of thyroglobulin(Tg) and thyroperoxidase (TPO) genes of rats. Methods Thirty SD male rats were randomly divided into six groups: control group, iodine-deficient group, low dose AP group ( 130 mg/kg), moderate dose AP group (260 mg/kg), high dose AP group (520 mg/kg) and high iodinecombined group. After the rats were exposed orally for 90 days, serum free-thyroxine (FT4), freetriiodothyronine (FT3) and thyroid stimulating hormone (TSH) were measured using radioimmunoassays.mRNA expression levels of thyroglobulin (Tg) and thyroperoxidase (TPO) genes were detected by real-time quantitative PCR. Results Serum FT4 levels in moderate dose AP group and high dose AP group were [(9.540±1.327) fmol/ml] and [(6.509±1.949) fmol/ml] respectively, which were significantly lower than that [ (13.505 ±1.276 ) fmol/ml] in control group (P＜0.05 or P＜0.01). Serum TSH level in high dose AP group was [(1.227±0.295) mIU/L], which was significantly higher than that [(0.545±0.282) mIU/L] in control group (P＜0.05). The mRNA expression levels of thyroglobulin (Tg)gene in all groups exposed to AP were significantly lower than that in control group (P＜0.01). The mRNA expression level of thyroperoxidase (TPO)gene in high dose AP group was significantly higher than that in control group (P＜0.05). Conclusion AP can reduce the serum FT3 and FT4levels of rats, increase the serum TSH level of rats and decrease obviously the mRNA expression levels of Tg and TPO genes. In addition, high iodine can reduce the toxic effects of AP on thyroid gland of rats to some extent.     

1,4-苯醌暴露下小鼠骨髓细胞p15基因表达和甲基化状态

目的 探讨1,4-苯醌(1,4-BQ)暴露下,体外原代培养的小鼠骨髓细胞中抑癌基因p15的mRNA表达及启动子区的甲基化状态.方法 体外分离小鼠骨髓细胞,测定0、0.1、1.0、5.0、10.0、20.0、40.0 μmol/L的1,4-BQ对小鼠骨髓细胞活力的影响,最终确定以0、0.1、1.0、10.0 μmol/L的1,4-BQ染毒骨髓细胞24 h;实时荧光定量聚合酶链反应(PCR)检测p15基因mRNA的表达变化;重亚硫酸盐测序法(BSP)检测启动子区域CpG岛的甲基化状态.结果 1,4-BQ对小鼠骨髓细胞具有剂量依赖的毒性作用,其LC50为8.3 μmol/L(95%CI:4.6～10.6 μmol/L).与对照组(100.0%)比较,10.0、20.0、40.0μmol/L 1,4-BQ染毒组小鼠的骨髓细胞生存率(35.9%、35.8%、30.5%)均明显降低,差异有统计学意义(P＜0.01).10.0μmol/L染毒组p15 mRNA表达为对照组的43%,与对照组比较,1.0和10.0 μmol/L染毒组p15基因mRNA表达量明显下降,差异有统计学意义(P＜0.05或P＜0.01).BSP测序结果显示,染毒组和对照组相同,p15基因启动子区域CpG岛上56个甲基化位点仍保持非甲基化状态.结论 1,4-BQ暴露可导致原代培养的小鼠骨髓细胞中p15基因的mRNA表达量下降,但启动子区域CpG岛的甲基化状态未受影响,提示甲基化不参与1,4-BQ介导的p15基因表达下调.

Abstract：

Objective To detect the expression and the CpG island methylation status of tumor suppressor gene p15 after exposure to 1,4-benzoquinone (1,4-BQ) in primary cultivated C57BL/6J mouse bone marrow cells in vitro. Methods The mouse bone marrow cells were isolated in vitro. The effect of 0, 0.1, 1, 5,10, 20, and 40 μmol/L 1,4-BQ on cell viability (CKK-8) was detected. 0, 0.1, 1, 10 μmol/L 1,4-BQ were used to intoxicate the mouse bone marrow cells for 24 h; Real-time PCR was employed to analyze the mRNA expression level of p15; The bisulfite sequencing PCR (BSP) was used to look into the methylation status of CpG islands in p15 promoter region. Results 1,4-BQ exhibited dose-dependent toxicity to mouse bone marrow cells, and the LC50 was 8.3 μmol/L (95% CI: 4.6-10.6 μmol/L). The mRNA expression of p15 in 10 μ mol/L group was only equivalent to 43% of control group. Compared with control group, the decrease of p15 mRNA expression in 1 and l0 μ mol/L concentration were obvious, and the differences had statistical significance(P＜0.05 or P＜0.01 ). BSP sequencing results were same between the exposure groups and control group, the 56 CpG sites on CpG islands remained in the state of unmethylated. Conclusion mRNA expression of p15 gene decreases after exposure to 1,4-BQ, but the CpG islands menthylation status in promoter is not affected, suggesting that methvlation does not participate in 1,4-BQ-mediated p15 gene expression decrease, other effect mechanisms still need to be investigated.     

出生后早期接触功夫菊酯对仔鼠大脑突触蛋白表达的影响

Objective To evaluate the influence on the synaptic protein expression in different brain regions of ICR mice after lambda-cyhalothrin (LCT) exposure during postnatal period. Methods Two male and 4 female healthy ICR mice were put in one cage. It was set as pregnancy if vaginal plug was founded.Offspring were divided into 5 groups randomly, and exposed to LCT (0.01% DMSO solution) at the doses of 0.1, 1.0 and 10.0 mg/kg by intragastric rout every other day from postnatal days (PND) 5 to PND13, control animals were treated with normal saline or DMSO by the same route. The brains were removed from pups on PND14, the synaptic protein expression levels in cortex, hippocampus and striatum were measured by western blot. Results GFAP levels of cortex and hippocampus in the LCT exposure group increased with doses, as compared with control group (P＜0.05), while Tuj protein expression did not change significantly in the various brain regions of ICR mice. GAP-43 protein expression levels in the LCT exposed mouse hippocampus and in female ICR mouse cortex increased with doses. as compared with control group (P＜0.05). Presynaptic protein (Synapsin Ⅰ) expression levels did not change obviously in various brain regions. However, postsynaptic density protein 95 (PSD95) expression levels of the hippocampus and striatum in male offspring of 10.0 mg/kg LCT group, of cortex of female LCT groups, and of female offspring in all exposure groups, of striatum, in 1.0 or 10.0 mg/kg LCT exposure groups significantly decreased (P＜0.05). Conclusions Early postnatal exposure to LCT affects synaptic protein expression. These effects may ultimately affect the construction of synaptic connections.     

镉对HepG2细胞DNA损伤作用以及对gadd基因表达的影响

目的 探讨氯化镉对HepG2细胞DNA损伤作用以及对gadd153和gadd45β启动子和mRNA表达的影响.方法 应用彗星试验检测氯化镉对HepG2细胞的DNA损伤作用;分别构建含有gadd153和gadd45β启动子和荧光素酶报告基因的载体pGADD153-Luc和pG45-Luc,荧光素酶活性检测反映gadd153和gadd45β启动子的活性,生物发光检测荧光素酶活性;反转录-聚合酶链反应(RT-PCR)检测gadd153和gadd45β基因mRNA的表达.结果 彗星试验结果显示,在100、300 μmol/L氯化镉处理细胞24 h后,Olive尾矩(分别为0.78±0.06、1.10±0.12)明显高于对照组(0.53±0.08),差异有统计学意义(P<0.05),并有良好的剂量-效应关系(r=0.9761,P<0.05);报告基因分析显示,1、5、10 μmol/L氯化镉处理组gadd153启动子表达[分别为(9.45±1.26)、(11.76±1.12)、(21.14±1.47)RIU/μg Pro]均明显高于对照组[(7.02±0.82)RIU/μg Pro]差异均有统计学意义(P<0.05),并有良好的剂量-效应关系(r=0.8755,P<0.05);5、10μmol/L氯化镉处理组gadd45β启动子表达明显高于对照组,差异有统计学意义(P<0.05),并有良好的剂量-效应关系(r=0.8856,P<0.05);RT-PCR结果显示,1、5、10μmol/L氯化镉处理组gadd153 mRNA表达均明显高于对照组,5、10 μmol/L氯化镉处理组gadd45β mRNA表达明显高于对照组,差异有统计学意义(P<0.05).结论 氯化镉可诱导HepG2细胞DNA损伤,较低剂量氯化镉即使未引起明显的DNA损伤,亦可促进HepG2细胞gadd153和gadd45β启动子和mRNA的表达.

Abstract：

Objective To investigate the effects of the cadmium chloride on the DNA damage and the expression of the gadd153 and gadd45β promoter and mRNA in HepG2 cells.Methods DNA damage induced by cadmium chloride was detected by comet assay.The plasmids (pGADD153-Luc and pG45-Luc ) containing DNA damage and repair inducible gene 153 and 45 (gadd153 and gadd45β) promoter and luciferase and gadd45β reporter gene were constructed.The activity of gadd 153 and gadd45β promoter were represented by the luciferase activity,the inducible luciferase activities was detected by bioluminescence.The expression of gaddl53 and gadd45β mRNA was detected by RT-PCR.Results The results of comet assay indicated that Olive Tail Moment induced by the cadmium chloride increased significantly at the dose of 100,300 μmol/L,compared with the control (P<0.05).The luciferase activity analysis showed that the expression levels of gaddl53 promoter increased significantly in 1,5,10 μmol/L treatment group,compared with the control (P<0.05).The expression levels of gadd45β promoter in 5,10μmol/L treatment group were significantly higher than that in control group (P<0.05).The expression levels of gaddl53 mRNA induced by cadmium chloride at the doses of 1,5,10 μ-mol/L and the expression levels of gadd45β mRNA induced at the doses of 5,10μmol/L were significantly higher than thoae in control group (P<0.05).Conclusion The cadmium chloride can induce the DNA damage and increase the expression levels of the gaddl53 and gadd45β promoters in HepG2 cells.     

出生后早期接触功夫菊酯对仔鼠大脑突触蛋白表达的影响

目的 观察出生后早期功夫菊酯(LCT)染毒对ICR仔鼠不同脑区突触蛋白表达的影响.方法 健康清洁级ICR小鼠按2∶4(雄∶雌)合笼受孕,出生小鼠每窝随机分为5组,分别为0.1、1.0和10.0 mg/kg LCT染毒组及溶剂对照组(0.01%二甲亚砜)和生理盐水对照组,每组雌雄各4只,仔鼠出生当天为出生后第0天(PND 0),PND5开始灌胃染毒,隔天1次,连续5次,PND14取材.蛋白质印迹法检测皮层、海马、纹状体突触蛋白的表达.结果 与溶剂对照组比较,各染毒组雄性仔鼠和10.0mg/kg组雌性仔鼠海马组织及1.0、10.0 mg/kg组雄性仔鼠和10.0 mg/kg组雌性仔鼠皮层胶质原纤维酸性蛋白(GFAP)表达升高,差异均有统计学意义(P＜0.05),且有剂量相关性(雄性:r海马=0.986,r皮层=0.945;雌性:r诲马=0.993,r皮层=0.969,P＜0.05);仔鼠各脑区的β微管蛋白Ⅲ型(Tuj)表达无明显改变;10.0 mg/kg组雄性仔鼠和各染毒组雌性仔鼠的海马及10.0 mg/kg组雌性仔鼠皮层生长相关蛋白43(GAP-43)表达升高,差异均有统计学意义(P＜0.05),且有剂量相关性(雄性:r海马=0.882;雌性:r海马=0.997,r皮层=0.99,P＜0.05);仔鼠各脑区的突触蛋白Ⅰ(Synapsin Ⅰ)表达无明显改变.10.0 mg/kg组雄性仔鼠海马、纹状体及雌性仔鼠皮层组织,各染毒组雌性仔鼠海马组织及1.0、10.0 mg/kg组纹状体组织突触后致密蛋白95(PSD95)表达降低,差异均有统计学意义(P＜0.05),PSD95表达与染毒剂量呈依赖性下降(雄性:r海马=-0.991;雌性:r纹状体=-0.996,r皮层=-0.995,P＜0.05).结论 出生后早期接触LCT,对仔鼠大脑突触蛋白的表达均有一定的影响;提示LCT可能影响仔鼠大脑突触联系的构建.

Abstract：

Objective To evaluate the influence on the synaptic protein expression in different brain regions of ICR mice after lambda-cyhalothrin (LCT) exposure during postnatal period. Methods Two male and 4 female healthy ICR mice were put in one cage. It was set as pregnancy if vaginal plug was founded.Offspring were divided into 5 groups randomly, and exposed to LCT (0.01% DMSO solution) at the doses of 0.1, 1.0 and 10.0 mg/kg by intragastric rout every other day from postnatal days (PND) 5 to PND13, control animals were treated with normal saline or DMSO by the same route. The brains were removed from pups on PND14, the synaptic protein expression levels in cortex, hippocampus and striatum were measured by western blot. Results GFAP levels of cortex and hippocampus in the LCT exposure group increased with doses, as compared with control group (P＜0.05), while Tuj protein expression did not change significantly in the various brain regions of ICR mice. GAP-43 protein expression levels in the LCT exposed mouse hippocampus and in female ICR mouse cortex increased with doses. as compared with control group (P＜0.05). Presynaptic protein (Synapsin Ⅰ) expression levels did not change obviously in various brain regions. However, postsynaptic density protein 95 (PSD95) expression levels of the hippocampus and striatum in male offspring of 10.0 mg/kg LCT group, of cortex of female LCT groups, and of female offspring in all exposure groups, of striatum, in 1.0 or 10.0 mg/kg LCT exposure groups significantly decreased (P＜0.05). Conclusions Early postnatal exposure to LCT affects synaptic protein expression. These effects may ultimately affect the construction of synaptic connections.     

三甲基氯化锡对亚慢性染毒大鼠肾氢钾ATP酶活力及蛋白与基因表达的研究

Objective To study the activity、protein and gene expression of renal HK-ATPase (HKA) in rats subchronicly exposed to trimethyltin chloride (TMT). Methods In subchronic toxic test (14-week), 55 female SD rats (age, 6 weeks) were divided randomly into 5 groups: control, low, medium, high and super high dosage, respectively, which drank water with TMT of 0, 8.20, 32.81, 131.25 and 262.50 μg·kg-1 ·d-1 for 14 weeks.Then serum K+ levels were measured; the activities of H K-ATPase (HKA) in kidneys were detected by the method of determinenate phosphorus content;Western Blot assay and real-time PCR were used to exam the protein and mRNA expression levels of HKA in kidneys, respectively. Results The serum K + level in super-high dosage group was (5.6±0.4) mmol/L, which was significantly lower than that [(6.9±0.3) mmol/L] in control group (P＜0.01).The HKA enzymatic activity of kidneys in low and super high dosage groups was 4.50±1.45 and 4.55±0.72 μmolPi·mg prot-1h-1, respectively, which were significantly lower than that (6.55±0.77 μmol Pi ·mg prot-1h-1) in control group (P＜0.05). Conclusion When rats were exposed subchronicly to TMT, the renal HKA activity could reduce, but the expression levels of HKA protein and mRNA did not decrease.     

Effects of oxidative stress and NF-κB levels in peripheral blood mononuclear cells on development of silicosis

Objective To investigate the change of indicators of oxidative stress in serum and NF-κB in peripheral blood mononuclear cells of patients with silicosis, and explore the mechanism of the development of silicosis. Methods The subjects were divided into (1) 200 workers exposed to SiO2 for at least 1 years in a foundry served as the dust-exposure group; (2) 130 cases with silicosis (Ⅰ phase silicosis 64 cases, Ⅱ phase 46 cases Ⅲ phase 20 cases) served as the silicosis goup; (3) 32 cases with 0+ phase silicosis in the foundry served as the observed group,(4)100 subjects from a hotel served as the control group. The serum including superoxide dismutase (SOD), nitric oxide (NO), serum glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), nitric oxide synthase (NOS), lipid malondialdehyde (MDA) and NF-κB protein levels in peripheral blood mononuclear cells were determined, respectively. Results Compared with the control group,NO levels in dust-exposed group and silicosis group significantly increased, and SOD decreased significantly (P＜0.05 or P＜0.01). Compared with the control group and dust-exposed group, T-AOC, NOS, MDA levels in silicosis group significantly increased (P＜0.05 or P＜0.01). GSH-Px in dust-exposed group and silicosis group were (231.164±36.484) and (270.469±39.228)U/md, respectively which were significantly than that [(223.360±46.838) U/ml] in control group (P＜0.05 or P＜0.01), and there was significant difference of GSHPx between the silicosis group and the dust-exposed group significantly (P＜0.01). GSH-Px level [(290.750±39.129) U/ml] in Ⅲ phase silicosis group were significantly higher than those [(256.906±21.41) and (259.594±34.79) U/ml] in observation group and Ⅰ phase silicosis group (P＜0.05). NF-κB levels [(72.06±9.12) and (85.25±11.64) ng/L] in dust-exposed group and silicosis group were significantly higher than that [(59.71±9.27) ng/L] in control group (P＜0.01), and there was significant difference of between the silicosis group and the dust-exposed group (P＜0.01). There was a positive correlation between serum GSH-Px level and the silicosis stages (r=0.507,P＜0.0l). Also there was a positive correlation between NF-κB level and silicosis stages, age, GSH-Px or NO levels (r=0.376, 0.243, 0.233, 0.221, P＜0.01). Conclusion The imbalance of oxidative and anti-oxidation system and the activation of NF-κB are related with the occurrence and development of silicosis. The monitoring of oxidative stress indicators and NF-κB is beneficial to the prediction and prognosis assessment of silicosis.     

MK801抑制乐果诱导的大鼠皮层神经元凋亡的作用研究

目的通过应用N-甲基-D-天门冬氨酸(NMDA)受体非竞争性拮抗剂MK801探讨兴奋性氨基酸神经递质在乐果诱导的新生大鼠皮层神经元凋亡中发挥的作用。方法在纯化的新生鼠皮层神经元中,加入终浓度为100μmol/L的乐果,并用50和100μmol/L NMDA受体非竞争性拮抗剂MK801对100μmol/L乐果染毒组进行干预。染毒后48小时收获细胞,TUNEL染色检测神经元凋亡情况;HPLC-FLD方法测定细胞内兴奋性氨基酸递质含量,RT-PCR检测NMDA受体NR2B亚基mRNA表达的变化,荧光探针DCFH-DA试剂盒检测细胞内活性氧水平。结果在纯化培养的皮层神经元中,100μmol/L乐果染毒48h后,与对照组相比,Tunel染色强度为对照组1.40倍(P<0.01);兴奋性氨基酸的含量均上升(P<0.01);细胞内ROS水平逐渐增高为对照组的2.47倍(P<0.01)。对100μmol/L乐果染毒组给予50和100μmol/L MK801干预后,高剂量干预组凋亡减少为干预前的79.6%(P<0.01),EAA含量下降(P<0.01);细胞内ROS水平下降为干预前的88.9%和74.8%(P<0.01),但仍远高于对照组细胞内活性氧水平(P<0.01);NR2B mRNA表达上升为干预前的1.59和2.22倍(P<0.01),显著高于对照组水平(P<0.01)。结论兴奋性氨基酸递质和细胞内活性氧共同参与乐果诱导的神经元凋亡。NMDA受体阻断剂MK801不仅能减少活性氧的生成并能降低神经元兴奋性氨基酸含量,从而减少乐果诱导的神经元凋亡。     

DNA聚合酶β对苯并[a]芘致细胞遗传毒性及基因组遗传不稳定性的影响

目的 研究DNA聚合酶β(polβ)表达水平对苯并[a]芘(BaP)致细胞遗传毒性及基因组遗传不稳定性的影响,为BaP的致癌分子机制提供实验依据.方法 采用3种具有相同遗传背景的小鼠胚胎成纤维细胞[polβ野生型(polβ+/+)、polβ缺陷型(polβ-/-)和polβ高表达型(polβoe)]作为模型,检测BaP对细胞的氧化损伤作用,细胞遗传毒性和基因组遗传不稳定性.结果 随着BaP浓度的增加,3种细胞的存活率和克隆形成能力均下降.5.00和20.00 μmol/L BaP染毒时,polβ-/-细胞产生的ROS荧光强度均大于polβ+/+和polβoe细胞,差异均有统计学意义(P＜0.05).在5.00和20.00μmol/L时,polβ-/-卢细胞SOD活力为(76.56±2.84)和(62.78±4.28) U/mg pro,低于对照组[(84.85±3.59) U/mg pro]和polβ+/+细胞[(85.21 ±3.20)和(76.90±3.38) U/mg pro],20.00 μmol/L BaP染毒组polβoe细胞SOD活力[(82.59±4.64) U/mg pro]低于对照组[(88.58±6.77) U/mg pro]但高于相同浓度染毒的polβ +/+细胞,差异均有统计学意义(P＜0.05).1.25、5.00和20.00 μmol/L BaP染毒组的polβ-/-细胞的微核形成率明显高于polβ +/+细胞,5.00和20.00 μmol/LBaP染毒组的polβ oe细胞的微核形成率明显低于pol β+/+细胞,差异均有统计学意义(P＜0.05).5.00和20.00 μmol/L BaP染毒组polβ-/-细胞的HPRT基因突变频率为26.16×10-6和37.51×10-6,polβ oe细胞为27.68×10-6和38.63×10-6,均明显高于polβ +/+细胞(19.76×10-6和24.78×10-6),差异均有统计学意义(P＜0.05).结论 Polβ在保护细胞免受BaP造成的细胞毒性和遗传毒性方面具有积极的作用,其正常表达对于维持细胞基因组遗传稳定性具有重要的意义.     

3种抗氧化剂对亚砷酸钠染毒人膀胱上皮细胞血管内皮生长因子表达的拮抗作用研究

目的探讨抗氧化剂褪黑素(melatonin,MEL)、N-乙酰半胱氨酸(N-acetyl cysteine,NAC)、维生素C(Vitamin,VC)对砷诱导人正常膀胱上皮(SV-HUC-1)细胞血管内皮生长因子(vascular endothelial growth factor,VEGF)表达的拮抗作用。方法将处于对数生长期的SV-HUC-1细胞暴露于含终浓度分别为0(对照)、0.5、1、2、4、8、10μmol/L亚砷酸钠的F12K完全培养基染毒24 h,或者含终浓度分别为4、10μmol/L亚砷酸钠的F12K完全培养基染毒0(对照)、4、12、24、48、72 h;联合暴露组在加入含终浓度分为4μmol/L亚砷酸钠的F12K完全培养基前30 min分别加入1%二甲基亚砜(DMSO)和抗氧化剂MEL、VC、NAC(终浓度分别为0.5、1、1 mmol/L),染毒24 h。分别采用Western blot法和RT-PCR法检测SV-HUC-1细胞VEGF蛋白和mRNA的表达水平。结果 10μmol/L亚砷酸钠染毒组SV-HUC-1细胞VEGF mRNA的表达水平高于对照组,差异有统计学意义(P0.05);且随着亚砷酸钠染毒剂量的升高,SV-HUC-1细胞VEGF mRNA的表达水平呈上升趋势。与对照组比较,4μmol/L亚砷酸钠染毒12、24、48 h及10μmol/L亚砷酸钠染毒24和48 h后SV-HUC-1细胞VEGF mRNA的表达水平均升高,差异有统计学意义(P0.05);且随着亚砷酸钠染毒时间的延长,各剂量组SV-HUC-1细胞VEGF mRNA的表达水平均呈先上升后下降的趋势。与对照组比较,4μmol/L亚砷酸钠+DMSO染毒组SV-HUC-1细胞中VEGF蛋白的表达水平均增加,差异有统计学意义(P0.05)。与4μmol/L亚砷酸钠+DMSO染毒组比较,亚砷酸钠+NAC染毒组SV-HUC-1细胞中VEGF蛋白的表达水平较高,差异有统计学意义(P0.05);而亚砷酸钠与MEL和VC联合染毒组SV-HUC-1细胞中VEGF蛋白的表达水平无明显改变。结论砷能诱导人正常膀胱上皮细胞VEGF表达增加,NAC能增加VEGF表达。     

高脂饮食对载脂蛋白E缺乏鼠维生素D受体表达及一氧化氮合酶活性影响研究

目的了解高脂饮食对载脂蛋白（apoE）缺乏鼠（apoE^-/-）维生素D受体（VDR）表达及内皮型一氧化氮合酶（eNOS）活性影响,探讨VDR在动脉粥样硬化（AS）形成的意义及可能机制。方法apoE^-／-小鼠与作为对照的C57BLP6J小鼠分别按数字表法分为正常食物组与高脂食物组,采用竞争蛋白结合放射免疫法检测小鼠血25-（OH）D水平,采用免疫荧光化学法及RT-PCR法检测小鼠主动脉VDR表达,应用硝酸还原酶法检测小鼠血一氧化氮（NO）含量和eNOS酶活力。结果高脂饮食进一步加重apoE-/-小鼠As病变、降低血25-（OH）D水平[血25-（OH）D：正常饲料C57BLP6J小鼠、高脂饲料C57BLP6J小鼠、正常饲料apoE。一小鼠、高脂饲料apoE-/-小鼠分别为[（26．44±1．28）ng／mL、（22．68±2．07）ng／mL、（1-7.46±4.2．22）ng／mL、（15．88±0．97）ng／mL,P〈0．01]。高脂饮食进一步上调apoE-/-小鼠主动脉VDR蛋白与mRNA表达水平[VDR蛋白分别为0．244±0．088、0．346±0．132、0．547±0．128、0．768±0．162,VDtlmRNA分另U为、0．228±O．08．3、0．375±0．103、0．451±0．117、0．597±0．131,P均〈0．01]。高脂饮食致apoE一小鼠血NO水平、eNOS酶活力明显增高[NO：（39．74±4．81）μmol／L、（48．1±5．24）ixmol／L、（67．34±6．14）tzmol／L、（86．74±8．05）txmol／L;eNOS：（8．6-t-O．77）u／L、（12．28±1．42）U／L、（15．96-t-O．92）U／L、（18．68±1．15）U／L,P均〈0．01]。血25-（OH）D水平与血浆中NO含量、eNOS酶活力及VDR表达呈负相关（P〈0．01）。结论apoE-/-小鼠血25-（OH）D水平降低,VDR表达量明显上调,血NO含量、eNOS酶活力增高,高脂饮食可进一步降低血25-（OH）13、NO水平,上调主动脉VDR表达,增加eNOS酶活力。高脂饮食、维生素D、apoE相互作用,影响As病变可能与NO、eNOS有关。     

阿托伐他汀对早期糖尿病肾病患者血清胱抑素C及尿微量蛋白的影响

目的 探讨阿托伐他汀对早期糖尿病肾病(DN)患者血清胱抑素C及尿微量蛋白的影响.方法 68例早期DN患者按照随机数字表法分为对照组和观察组,每组34例,对照组予常规治疗,观察组在常规治疗基础上予阿托伐他汀治疗,比较两组治疗前后血脂、血清胱抑素C、尿白蛋白排泄率(UAER)、尿微量蛋白[微量白蛋白(MAU)、α1微球蛋白(α1-MG)、β2微球蛋白(β 2-MG)]的变化.结果 观察组治疗后总胆固醇(TC)、三酰甘油(TG)、血清胱抑素C、UAER、MAU、α1-MG、β2-MG较治疗前均显著下降[(4.32±1.26) mmol/L比(5.65±1.38) mmol/L,( 1.67±0.64) mmol/L比(2.53±0.96) mmol/L,( 1.29±0.38) mg/L比(1.74±0.51)mg/L,(61.09±18.45)μg/min比(86.42±21.34)μg/min,(5.73±4.81) mg/L比(23.16±9.73) mg/L,( 1.41±1.21) mg/L比(4.76±1.24) mg/L,(1.21±0.13) mg/L比(2.58±0.26) mg/L](P＜0.01或＜0.05);对照组治疗后TC、TG、血清胱抑素C较治疗前有所下降,但差异无统计学意义(P＞0.05),而UAER、MAU、α1-MG、β2-MG与治疗前比较差异有统计学意义(P＜0.01或＜0.05),但下降程度不及观察组(P＜ 0.05或＜0.01).结论 阿托伐他汀可显著降低早期DN患者血清胱抑素C及尿微量蛋白水平,起到肾脏保护作用.     

血清内脂素水平与2型糖尿病的关系

目的 探讨血清内脂素(visfitin)水平与2型糖尿病(T2DM)之间的相关性.方法 采用酶联免疫吸附(ELISA)法对临床上糖调节受损(IGR)40例患者(IGR组)、T2DM 106例患者(T2DM组)和健康对照者86例(对照组)进行空腹血清visfatin水平的检测.结果 空腹血清visfatin水平在IGR组[(19.93±6.89)μg/L]、T2DM组[(29.53±11.33)μg/L]依次增高,且与对照组[(16.12±5.24)μg/L]相比均显著增高(P＜0.01);空腹血清visfatin水平与腰臀比呈正相关(r=0.161,P＜0.05),与三酰甘油、低密度脂蛋白胆固醇、糖化血红蛋白、空腹血糖、空腹胰岛素、lg稳态模型胰岛素抵抗指数(HOMA-IR)呈显著正相关(r=0.189、0.266、0.643、0.574、0.285、0.526,P＜0.01),与高密度脂蛋白胆固醇呈显著负相关(r=-0.377,P＜0.01);以visfatin为应变量进行多重线性回归分析,糖化血红蛋白(β=0.512,P=0.000)、lgHOMA-IR(β=0.172,P=0.026)、腰臀比(β=0.119,P=0.036)进入方程.结论 visfatin可能参与了血糖、血脂代谢的调节,且与胰岛素抵抗密切相关;visfatin可能是T2DM的危险因素之一.

Abstract：

Objective To investigate the correlation between serum level of visfatin and type 2 diabetes mellitus (T2DM). Methods Impaired glucose regulation (IGR) group consisted of 40 patients,T2DM group consisted of 106 patients, while control group consisted of 86 subjects. The serum visfatin levels of all groups were detected by enzyme linked immunosorbent assay (ELISA). Results Fasting serum visfatin levels in IGR group and T2DM group were significantly higher than those in control group [(19.93 ±6.89) μg/L and (29.53 ± 11.33) μg/L vs. (16.12 ± 5.24) μ g/L, P ＜ 0.01]. Fasting serum visfatin levels positively correlated with waist-to-hipratio (WHR) (r = 0.161, P ＜ 0.05); significantly positively correlated with triacylglycerol (TG), low density lipoprotein cholesterol (LDL-C), glycosylated hemoglobin (HbA1c),fasting plasma glucose (FPG), fasting insulin (FINS), lg Homeostasis model assessment-insulin resistance index (HOMA-IR) (r = 0.189,0.266,0.643,0.574,0.285,0.526,P ＜ 0.01), and significantly negatively correlated with high density lipoprotein cholesterol (HDL-C)(r =-0.377,P ＜0.01). When visfatin was analyzed as a dependent variable in multiple linear regression, HbA1c (β = 0.512, P = 0.000), lg HOMA-IR (β= 0.172, P = 0.026), WHR (β = 0.119, P = 0.036) were into the equation. Conclusion Visfatin may be involved in glucose and lipid metabolism regulation, and closely related with insulin resistance; visfatin may be a risk factor for T2DM.     

甲状腺功能减低孕鼠补充甲状腺素对子代脑组织同源盒基因Nkx2.1mRNA表达的影响

目的 通过对妊娠期甲状腺功能减低(甲低)大鼠补充左旋甲状腺素(L-thyroxine,L-T4),探讨甲状腺素对子代鼠脑组织同源盒基因Nkx2.1mRNA表达影响,探讨该基因的表达与甲状腺素水平之间的关系.方法 Wistar雌性大鼠120只,按体重分层随机分为对照组、甲低非治疗组,甲低孕鼠妊娠早期(妊娠第1～17天)补充L-T4高、中、低剂量组,甲低孕鼠妊娠晚期(妊娠第18天至分娩后第20天)补充L-T4高、中、低剂量组,共8组,每组15只;补充L-T4高、中、低剂量分别为:3.5、2.0、0.5μg/100 g体重.各组均给予低碘饮食,对照组饮用碘浓度为200 μg/L碘酸钾溶液,其余7组饮用去离子水.3个月后各组均与正常雄性大鼠交配,确定受孕后各甲低给药组于不同时期给予补充L-T4.各组分别取孕第17天胎鼠、新生及出生后第20天龄仔鼠前脑组织,实时荧光定量PCR(Real-time PCR)检测Nkx2.1mRNA水平.结果 甲低孕鼠妊娠早期补充L-T4高、中、低剂量组,甲低孕鼠妊娠晚期补充L-T4高、中、低剂量组,甲低非治疗组、对照组大鼠血清TT3分别为(0.85±0.17)、(0.81±0.18)、(0.86±0.21)、(0.85±0.20)、(0.89±0.18)、(0.85±0.20)、(0.86±0.20)、(1.08±0.07)nmol/L(F=4.08,P＜0.01);TT4分别为(0.43±0.16)、(0.39±0.11)、(0.39±0.13)、(0.43±0.17)、(0.51±0.19)、(0.43±0.16)、(0.41±0.15)、(39.43±14.16)nmol/L(F=31.99,P＜0.01);FT3分别为(3.29±0.61)、(3.29±0.61)、(3.24±0.61)、(3.28±0.63)、(3.31±0.59)、(3.28±0.50)、(3.24±0.49)、(4.93±0.46)pmol/L(F=5.79,P＜0.01);FT4分别为(3.38±0.80)、(3.31±0.67)、(3.29±0.73)、(3.27±0.71)、(3.48±0.81)、(3.56±0.66)、(3.29±0.61)、(27.29±4.53)pmol/L(F=26.34,P＜0.01).甲低非治疗组在妊娠第17天胎鼠Nkx2.1mRNA水平(9.15×10-5±9.17 × 10-5)低于对照组胎鼠(65.1×10-5±40.90×10-5)(t=66.224,P＜0.05);甲低非治疗组在新生期仔鼠Nkx2.1mRNA水平(3.16×10-5±0.142×10-5)低于对照组仔鼠(55.6×10-5±51.05×10-5)(t=102.225,P＜0.05);甲低非治疗组在生后第20天仔鼠Nkx2.1mRNA水平(8.09×10-5±8.21×10-5)低于对照组仔鼠(13.9×10-5±7.43×10-5)(t=9.235,P＜0.05).甲低孕鼠妊娠早期补充L-T4中等剂量组在妊娠第17天胎鼠、新生、生后第20天仔鼠脑组织Nkx2.1mRNA表达水平逐渐降低,分别为(57.1×10-5±22.90×10-5)、(30.8×10-5±27.20×10-5)、(17.1×10-5±0.623×10-5)(F=13.394,P＜0.01).甲低孕鼠妊娠早期补充L-T4中等剂量组妊娠第17天胎鼠、新生、生后第20天仔鼠脑组织Nkx2.1mRNA水平接近对照组,差异无统计学意义(t值分别为0.225、0.336、0.345,P值均＞0.05).结论 大鼠脑组织同源盒基因Nkx2.1mRNA的表达与甲状腺素水平存在关联.     

不同形态砷化合物对非致瘤性人源性肝细胞的毒性作用

目的探讨不同形态砷化合物对非致瘤性人源性肝(QSG7701)细胞的毒性及氧化应激作用。方法将处于对数生长期的QSG7701细胞分别暴露于亚砷酸钠(砷浓度为1、5、25、100μmol/L)、砷酸钠(砷浓度为10、25、100、500μmol/L)及MMA和DMA(砷浓度均为100、500、1 000、2 000μmol/L)培养24 h,并设对照(含10%胎牛血清的RPMI-1640培养基)。采用四甲基偶氮唑盐(MTT)法测定细胞活性;检测细胞培养液中乳酸脱氢酶(LDH)释放率、谷草转氨酶(AST)活力、总超氧化物歧化酶(T-SOD)活力和丙二醛(MDA)含量。结果一定浓度的As~(Ⅲ)(≥1μmol/L)、As~Ⅴ(≥10μmol/L)、MMA(≥100μmol/L)和DMA(≥2 000μmol/L)均能显著降低QSG7701细胞的存活率,差异有统计学意义(P0.05);且随着As~(Ⅲ)、As~Ⅴ及MMA和DMA染毒浓度的升高,QSG7701细胞的存活率呈逐渐降低的趋势。经计算,QSG7701细胞暴露于As~(Ⅲ)、As~Ⅴ、MMA和DMA 24 h的IC_(50)分别为170.89、863.73、2 235.67、4 045.31μmol/L,对QSG7701细胞生长的抑制作用依次为As~(Ⅲ)As~ⅤMMADMA。在当As~(Ⅲ)浓度为5~100μmol/L、As~Ⅴ浓度为10~500μmol/L及MMA中的砷浓度为1 000、2 000μmol/L和DMA中的砷浓度为2 000μmol/L时,QSG7701细胞的LDH释放率均高于对照组,差异有统计学意义(P0.05);另外,当As~(Ⅲ)浓度为1~100μmol/L、As~Ⅴ浓度为10~500μmol/L及MMA和DMA中的砷浓度为100~2 000μmol/L时,QSG7701细胞培养液中的AST活力均高于对照组;且随着As~(Ⅲ)、As~Ⅴ及MMA和DMA染毒浓度的升高,QSG7701细胞的LDH释放率和细胞培养液中的AST活力呈上升的趋势。与对照组比较,当As~(Ⅲ)浓度为5~100μmol/L、As~Ⅴ浓度为10~500μmol/L时,QSG7701细胞中的MDA含量均较高,而T-SOD活力均较低;与对照组比较,当MMA和DMA中的砷浓度均为500~2 000μmol/L时,QSG7701细胞中的MDA含量均较高;而当MMA中的砷浓度为100~2 000μmol/L和DMA中的砷浓度为100、500μmol/L时,QSG7701细胞中的T-SOD活力均较低,差异有统计学意义(P0.05)。结论在本实验条件下,4种砷化合物均可不同程度地损伤肝细胞膜,破坏肝细胞的氧化平衡状态,产生氧化应激并导致脂质过氧化,对人肝细胞QSG7701的毒性作用依次为As~(Ⅲ)As~ⅤMMADMA。     

RAS拮抗剂调节血管平滑肌细胞增殖、凋亡因子表达

目的探讨血管紧张素转化酶抑制剂卡托普利及血管紧张素Ⅱ(AngⅡ)受体拮抗剂氯沙坦对AngⅡ诱导的肿瘤坏死因子-α(TNF-α)、转化生长因子-β1(TGF-β1)表达的干预作用。方法体外原代培养Wistar大鼠主动脉平滑肌细胞,收集不同AngⅡ浓度和作用时间下的细胞和卡托普利组、氯沙坦组和二者联合作用组的细胞,以逆转录(RT)-PCR检测细胞中TNF-α和TGF-β1 mRNA的表达。结果 TNF-αmRNA表达量随AngⅡ浓度和作用时间增加而增加,AngⅡ浓度为10-7、10-6、10-5、10-4 mol/L时表达量分别为(0.43±0.05)、(0.81±0.13)、(0.97±0.17)、(1.09±0.19),与对照组(0.11±0.03)比较,差异有统计学意义(P<0.05或0.01);一定浓度卡托普利(5×10-6mmol/L)、氯沙坦(5×10-6 mmol/L)可明显抑制AngⅡ这一作用;TGF-β1 mRNA表达量随AngⅡ浓度和作用时间增加而明显增加,具有浓度依赖性;在AngⅡ10-7、10-6、10-5和10-4 mol/L时,卡托普利组mRNA表达量分别为(0.19±0.03)、(0.23±0.05)、(0.38±0.14)、(0.34±0.07),较AngⅡ组分别降低了59.57%、73.26%、54.44%和66.67%,差异均有统计学意义(P<0.05或0.01),氯沙坦组分别为(0.17±0.03)、(0.39±0.11)、(0.41±0.12)和(0.39±0.08),较AngⅡ组分别下降了63.82%、54.65%、54.44%和61.76%,差异均有统计学意义(P<0.05)。结论 AngⅡ可促进血管平滑肌细胞TNF-α、TGF-β1 mRNA表达,且有时间和浓度依赖关系;卡托普利、氯沙坦对AngⅡ诱导的血管平滑肌细胞TNF-α、TGF-β1 mRNA表达均有抑制作用,二者联合作用时抑制作用最明显。