亚硒酸钠和硒酸钠对小白菜生长生理特性的影响

以小白菜品种'秦白2号'为材料,采用盆栽试验研究了不同浓度亚硒酸钠[Se(IV)]和硒酸钠[Se(VI)]胁迫对小白菜生长生理特性的影响及其生理机制,为土壤硒污染修复及其合理开发利用提供理论依据.结果表明,Se(IV)≤10.0 mg·kg-1时,小白菜的叶长、叶宽显著下降,而生物量没有受到显著影响;Se(VI)≤1.0 mg·kg-1时,叶长、叶宽、生物量没有显著变化;更高浓度处理时,叶长、叶宽、生物量均随外源Se(IV)和Se(VI)处理浓度的增大而急速下降.Se(IV)≤40.0 mg·kg-1和Se(VI)≤20.0 mg·kg-1处理均对小白菜叶片叶绿素含量无显著影响,但更高浓度外源Se(IV)和Se(VI)却显著抑制了叶绿素合成.低浓度外源Se(IV)和Se(VI)均使小白菜叶片谷胱甘肽过氧化物酶(GSH-Px)活性上升,膜质过氧化物(MDA)含量下降,对超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性及脯氨酸含量无显著影响;高浓度硒使MDA含量、脯氨酸含量及SOD活性上升,而使GSH-Px活性和CAT活性下降;外源Se(IV)和Se(VI)均使过氧化物酶(POD)活性降低.研究发现,低浓度外源Se(IV)和Se(VI)均提高了小白菜的抗氧化作用,从而促进小白菜叶片叶绿素的合成和生长,高浓度时则相反;低浓度硒的抗氧化作用和高浓度硒的过氧化作用均以Se(VI)大于Se(IV).说明硒酸钠的有效性和毒害作用均大于亚硒酸钠.     

沉默HDGF基因抑制HepG2细胞的增殖和脂质代谢

目的:探讨肝癌衍生生长因子(HDGF)对HepG2细胞增殖和脂质代谢的影响。方法:用脂质体包裹si RNA的方法沉默HDGF基因,用实时荧光定量PCR法和蛋白质免疫印迹法检测HDGF在mRNA和蛋白水平的变化,检测细胞总甘油三酯、胆固醇含量并用油红O染色,CCK-8检测及琼脂糖凝胶克隆形成,实时荧光定量PCR法检测脂质代谢相关酶的mRNA表达。结果:将靶向HDGF小干扰(si RNA-HDGF)转染到HepG2细胞后,可明显抑制HDGF的mRNA表达(P0.001)和蛋白表达。HDGF蛋白抑制后,细胞增殖在48 h(P0.01)、72 h(P0.001)和96 h(P0.001)均明显降低;细胞内总甘油三酯及胆固醇水平也明显降低(P0.05,P0.01)。此外,油红O染色显示细胞内脂滴有明显的减少。脂质代谢相关酶脂肪酸合成酶(FASN)、羟基-3-甲基戊二酰辅酶A还原酶(HMGCR)、硬脂酰辅酶A去饱和酶(SCD)及ATP-柠檬酸裂解酶(ACLY)的mRNA表达均明显降低(P0.001,P0.001,P0.001,P0.01)。结论:抑制HDGF的表达可明显降低HepG2细胞内脂质代谢水平并抑制其增殖。     

体外培养的哺乳动物细胞的葡萄糖和谷氨酰胺代谢

综述体外培养哺乳动物细胞的葡萄糖和谷氨酰胺代谢。大部分的葡萄糖通过糖酵解途径为细胞提供中间代谢物质和能量 ,最终生成乳酸 ,只有很少部分进入TCA循环和磷酸戊糖途径。谷氨酰胺通过谷氨酰胺酶生成谷氨酸 ,并进一步通过谷氨酸脱氢酶或转氨酶生成α -酮戊二酸进入TCA循环 ,为细胞提供中间代谢物质和能量。糖酵解和谷氨酰胺代谢 (glutaminolysis)受葡萄糖和谷氨酰胺的影响而相互调节。     

亚硒酸钠对P16蛋白在Wistar大鼠生精细胞表达的影响

目的探讨亚硒酸钠对P16蛋白在Wistar大鼠生精细胞表达的影响.方法断乳雄性Wistar大鼠30只随即分为正常对照组、低硒(2mg/L)和高硒(4mg/L)组,连续饮用含硒水43周后,取大鼠睾丸组织,用免疫组织化学SP法显示P16蛋白在大鼠睾丸中的表达,并对免疫组织化学结果进行定性、定位、图像分析和统计学处理.结果P16蛋白主要表达在精原细胞和精子的核内,免疫组织化学阳性细胞的平均光密度(MOD)和面数密度(NA)加硒组略高于正常对照组(P>0.05).结论本实验结果提示:饮水中加入2mg/L,4mg/L亚硒酸钠对生精细胞P16蛋白的表达无显著的影响.     

亚硒酸钠对大鼠晶体上皮细胞αA晶体蛋白基因转录的影响

在体外观察了亚硒酸钠（Ｎａ２ＳｅＯ３）作用于大鼠晶体上皮细胞（ＲＬＥｃｅｌｌｓ）而引起其晶体蛋白基因转录的改变,对不同浓度的硒在体外对αＡ晶体蛋白基因转录的影响作了初步的研究,结果发现,随着亚硒酸钠浓度的升高,αＡ基因的转录下降;而当亚硒酸钠浓度升至５×１０＾－５ｍｏｌ／Ｌ时,αＡ基因的转录又呈反跳性回升,提示硒在致障过程中对晶体蛋白基因转录的影响作用不可忽视。同时αＡ晶体蛋白在晶体细胞内,至少应     

共轭亚油酸对HepG2细胞脂质沉积的影响

目的:研究共轭亚油酸(conjugated linoleic acid,CLA)对HepG2细胞脂肪沉积的影响,以探讨其对肝脏脂肪沉积的可能机制.方法:体外培养HepG2细胞,不同浓度CLA(0、10、50、100 μmol.1-1)作用24小时后,100 nmol.1-1胰岛素作用1小时.以比色法测定培养液中游离脂肪酸的含量,油红O染色观察细胞脂肪沉积,Western-blot检测Akt和P-Akt蛋白表达.结果:随着CLA浓度增加,培养液中的游离脂肪酸含量显著降低,细胞中红染脂滴增多,Western-blot结果发现,Akt蛋白的磷酸化水平增高.结论:CLA可以增加细胞内脂肪合成和细胞中Akt蛋白的磷酸化水平.     

不同浓度亚硒酸钠溶液对水杉种子萌发的影响

硒元素是植物生长所需的微量元素。在水杉母树主要生长所在地恩施境内形成立体的硒资源环境,而该区的水杉群落天然更新困难,林下鲜见更新幼苗或幼树。因此,结合硒资源,研究硒元素与水杉种子萌发的相互关系对水杉的天然更新繁育具有重要意义。为了揭示硒元素对水杉种子发芽的影响,该研究通过测定不同环境条件(温度:20、25、30 ℃; 光照:12 h光照/12 h黑暗、24 h全黑暗; 是否浸种)下原生水杉种子的萌发率,筛选出最适萌发条件,并在此条件下采用不同浓度(0、0.25、0.5、1.0、2.0、4.0、8.0、16.0 mg·L^-1)的亚硒酸钠对水杉种子进行处理,观察其萌发的变化。结果表明:当使用浓度为0.25 mg·L^-1的亚硒酸钠溶液处理水杉种子时,种子的发芽率、发芽势和发芽指数都为最高,分别为34.0%、29.0%、13.9; 当亚硒酸钠浓度大于0.25 mg·L^-1时,水杉种子的发芽率、发芽势和发芽指数开始随着浓度的增加而降低,在亚硒酸钠浓度为16.0 mg·L^-1时,三个指标都达到最低值,分别为0.5%、0%、0.025。由此可知,低浓度(0～0.25 mg·L^-1)的亚硒酸钠处理对水杉种子的萌发有一定的促进作用,而高浓度(>0.25 mg·L^-1)的亚硒酸钠处理对水杉种子的萌发则有一定的抑制作用。     

亚硒酸钠对糖尿病肾病大鼠肾脏Nephrin表达的影响与意义

探讨亚硒酸钠对糖尿病肾病大鼠肾脏Nephrin表达的影响及二者间的关系,从而研究亚硒酸钠和Nephrin在糖尿病肾病中的作用机制.通过链脲佐菌素法及给予高脂饮食诱导模拟大鼠糖尿病肾病模型,实验设空白对照组、糖尿病肾病对照组、亚硒酸钠干预组,亚硒酸钠干预组每日给予亚硒酸钠溶液灌胃,其它组给予等量生理盐水灌胃.灌胃10周后处死大鼠,取血、尿标本测相关生化指标.取肾脏组织戊二醛固定制作切片电镜下观察超微结构改变,取肾脏组织多聚甲醛固定制石蜡切片光镜下观察病理改变和免疫组化定位蛋白表达.取肾脏组织RT-PCR检测Nephrin的mRNA表达、Western Blotting检测nephrin的蛋白表达,分析各组数据的统计差异.结果发现亚硒酸钠干预组大鼠基本状况和生化指标较糖尿病肾病对照组明显改善,光镜和电镜下观察病理改变和超微结构病变较糖尿病肾病对照组明显减轻.免疫组化nephrin蛋白表达着色糖尿病肾病对照组较空白对照组减少,亚硒酸钠干预组较糖尿病肾病对照组着色明显增多.Nephrin mRNA和蛋白表达糖尿病肾病对照组较空白对照组明显降低,而亚硒酸钠干预组较糖尿病肾病对照组升高,但低于空白对照组,差异均有统计学意义（P〈0．05）．亚硒酸钠明显促进肾脏Nephrin表达,改善了糖尿病肾病,表明亚硒酸钠和Nephrin在防治和延缓糖尿病肾病的发生发展中可能起重要作用．     

The Effect of Sodium Selenite on the Expression of Genes of Endoplasmic Reticulum-Resident Selenoproteins in Human Fibrosarcoma Cells

Biophysics - Abstract—Sodium selenite, which is one of the most common selenium compounds, is considered a potential anticancer agent that can decrease cell viability; this compound is...     

Influence of Sodium Selenite on the mRNA Expression of the Mammalian Selenocysteine-Containing Protein Genes in Testicle and Prostate Cancer Cells

The sodium selenite concentration that reduces the viability of Du-145 human prostate adenocarcinoma cells and F-9 mouse testicular teratocarcinoma cells was determined. We investigated the effect of sodium selenite on the mRNA expression level of the genes encoding mammalian selenocysteine-containing glutathione peroxidases and thioredoxin reductases (key antioxidant enzymes involved in the regulation of intracellular thiol redox balance), endoplasmic reticulum selenoproteins, and selenoproteins located in the testes and prostate.     

Effects of Glucose Availability on Expression of the Key Genes Involved in Synthesis of Milk Fat,Lactose and Glucose Metabolism in Bovine Mammary Epithelial Cells

As the main precursor for lactose synthesis, large amounts of glucose are required by lactating dairy cows. Milk yield greatly depends on mammary lactose synthesis due to its osmoregulatory property for mammary uptake of water. Thus, glucose availability to the mammary gland could be a potential regulator of milk production. In the present study, the effect of glucose availability on expression of the key genes involved in synthesis of milk fat, lactose and glucose metabolism in vitro was investigated. Bovine mammary epithelial cells (BMEC) were treated for 12 h with various concentrations of glucose (2.5, 5, 10 or 20 mmol/L). The higher concentrations of glucose (10–20 mmol/L) did not affect the mRNA expression of acetyl-CoA carboxylase, diacyl glycerol acyl transferase, glycerol-3 phosphate acyl transferase and α-lactalbumin, whereas fatty acid synthase, sterol regulatory element binding protein-1 and beta-1, 4-galactosyl transferase mRNA expression increased at 10 mmol/L and then decreased at 20 mmol/L. The content of lactose synthase increased with increasing concentration of glucose, with addition of highest value at 20 mmol/L of glucose. Moreover, the increased glucose concentration stimulated the activities of pyruvate kinase and glucose-6-phosphate dehydrogenase, and elevated the energy status of the BMEC. Therefore, it was deduced that after increasing glucose availability, the extra absorbed glucose was partitioned to entering the synthesis of milk fat and lactose by the regulation of the mRNA expression of key genes, promoting glucose metabolism by glycolysis and pentose phosphate pathway as well as energy status. These results indicated that the sufficient availability of glucose in BMEC may promote glucose metabolism, and affect the synthesis of milk composition.     

糖耐康含药血清对高糖状态下大鼠肝细胞糖脂代谢的影响

摘要目的：研究糖耐康含药血清对高糖状态下大鼠肝细胞糖脂代谢的影响。方法：通过培养大鼠肝细胞,在高糖诱导肝细胞胰岛素抵抗状态下,给予高、中、低剂量的糖耐康含药血清共培养24h后,观察肝细胞增殖情况,用葡萄糖氧化酶法检测细胞的葡萄糖消耗量,培养基和肝细胞内TG含量,肝细胞糖原含量。结果：与正常组比较,高糖刺激下,肝细胞增殖显著受到抑制（P〈O．叭）、葡萄糖消耗量和糖原含量减少（P〈0．01）,TG含量增加（P〈O．01）;与高糖组比较,吡格列酮组与TNK各剂量上述情况有不用程度的改善。作用效果类似。结论：糖耐康含药血清具有改善高糖环境下肝脏糖脂代谢紊乱的作用,可能与增加肝细胞胰岛素敏感性改善IR有关。     

2型糖尿病模型大鼠肝脏脂代谢相关基因的筛选及生物信息学分析

肝的脂肪代谢异常和胰岛素抵抗（insulin resistance,IR）对促进2型糖尿病（type 2 diabetes mellitus,T2DM）的发生与发展具有显著影响。但此过程复杂,参与调控基因目前尚未完全清楚。有研究表明,脂肪酸分解、氨基酸代谢、肝糖原合成等生物过程对糖尿病的形成具有促进作用。为了阐明这一调控机制,本文通过基因芯片技术研究GK（Goto-Kakizaki）大鼠和WKY（Wistar-Kyoto）大鼠肝差异基因对肝的脂肪代谢和胰岛素抵抗的影响,探讨可引起2型糖尿病发病的分子机制。从基因表达数据库（GEO）获取GSE13271基因表达谱,并对原始数据进行标准化处理。通过GO（Gene Ontology）、KEGG（Kyoto Encyclopedia of Genes and Genomes enrichment）、String和Cytoscape软件对差异表达基因进行功能分析。结果从GK和WKY大鼠中分别获得179和278个差异基因,同时从排名前10的路径中筛选出21个差异基因(Aldh1a1, Cyp2c22, bp2,Fabp7,Cyp4a3, Acot1, Acot2,Hsd17b2, Ech1, Hmgcl,Bdh1, Crot, Pex11a, Cpt1a, Hadhb, Gda, Elovl2, Prodh, Agpat3, Sardh, Pigu),将这些基因与前10个的GO term取交集。最终得到10个显著差异基因(Aldh1a1, Fabp2, Acot1, Acot2, Ech1, Hmgcl, Bdh1, Crot, Cpt1a, Hadhb),功能分析结果显示,肝组织相关基因通过一系列生物过程对肝的脂肪代谢和胰岛素抵抗产生调节作用,从而也为临床糖尿病的治疗以及新作用靶点的发现提供更多参考依据。     

Modulation of Lipid Metabolism by Deep-Sea Water in Cultured Human Liver (HepG2) Cells

It has been found that deep-sea water was associated with lower serum lipid in animal model studies. Herein, we investigated whether DSW exerted a hypolipidemic activity and further elucidated how DSW modulated lipid metabolism in HepG2 cells. Preliminary animal studies showed that DSW exhibited potency to decrease serum total cholesterol, triglycerides, and LDL cholesterol, and increase HDL cholesterol, and the hepatic lipid contents were also significantly lower in the DSW group. When DSW was added to HepG2 cells, it decreased the lipid contents of hepatocyte through the activation of AMP-activated protein kinase, thus inhibiting the synthesis of cholesterol and fatty acid. Besides, LDL receptor was upregulated by activation of sterol regulatory element-binding protein-2. In addition, the levels of apolipoprotein AI and cholesterol 7-alpha-hydroxylase were also raised. Our investigation provided mechanisms by which DSW modulated lipid metabolism and indicated that DSW was worthy of further investigation and could be developed as functional drinking water in the prevention and treatment of hypolipidemic and other lifestyle-related diseases.     

Effects of Sodium Selenite and Dithiothreitol on Expression of Endoplasmic Reticulum Selenoproteins and Apoptosis Markers in MSF7 Breast Adenocarcinoma Cells

Molecular Biology - The endoplasmic reticulum (ER) stress inducers dithiothreitol (DTT) and sodium selenite (SS) were tested for effect on expression of ER selenoproteins and apoptosis markers in...     

Lipid Efflux Mediated by Alkylphospholipids in HepG2 Cells

Antitumoural alkylphospholipid (APL) analogues alter cholesterol homoeostasis in HepG2 cells by interfering with cholesterol transport from the plasma membrane to the endoplasmic reticulum (ER) and at the same time stimulating the release of considerable quantities of membrane cholesterol. The capacity of APLs to stimulate cholesterol efflux is suppressed when cells are incubated simultaneously with APLs and serum whilst the inhibition of cholesterol transport to the ER (measured in terms of the synthesis of esterified cholesterol) persists, indicating that both effects are independent of each other. Interestingly, our results suggest that both raft and non-raft membrane domains contribute to the cholesterol released to APLs. In addition, a marked efflux of choline-bearing phospholipids (phosphatidylcholine (PC) and sphingomyelins (SM)) was found to be related to this release of cholesterol. Finally, we observed that APL micelles composed of cholesterol might act as donor/acceptor cholesterol systems. Thus, the findings of this study clearly demonstrate that antitumoural APLs act as extracellular acceptors, stimulating cholesterol and phospholipid efflux, although they may also play a role as cholesterol donors.     

氨基葡萄糖对SD 大鼠肝脏糖代谢相关蛋白表达差异性的研究

目的:研究氨基葡萄糖对SD大鼠肝脏中糖代谢相关蛋白表达的影响。方法:选取成年雌性SD大鼠48只,按体重随机分成4组,分别为氨基葡萄糖高、中、低剂量组和阴性对照组。分别灌胃500mg/Kg,250mg/Kg,125mg/Kg的氨基葡萄糖溶液和1ml/100g的生理盐水,连续灌胃28天。实验结束时处死试验动物,用免疫组织化学法检测肝脏中蛋白激酶,己糖激酶,一氧化氮合酶,葡萄糖转运蛋白4和葡萄糖转运蛋白2的表达情况。结果:试验期间各组动物生长发育情况良好,灌胃不同剂量氨基葡萄糖的大鼠肝脏中五种蛋白的表达与阴性对照组相比均无显著性差异(P≥0.05)。结论:氨基葡萄糖未导致肝脏中糖代谢相关蛋白表达的异常,提示服用氨基葡萄糖不会影响肝脏的糖代谢过程。