Arylamine N-acetyltransferases: a new inhibitor of apoptosis in HepG2 cells

Objective: To explore how arylamine N-acetyltransferases (NATs) is related to cell apoptosis. Methods: NAT activity in apoptotic HepG2 cells was measured using high performance liquid chromatography (HPLC); the apoptosis rate of HepG2 cells acted upon by an NAT inhibitor was measured using flow cytometry. Results: NAT activity was lowered in apoptotic HepG2 cells;apoptosis rate induced by camptothecin (CAM) increased after inhibition of NAT activity in HepG2 cells. Conclusion: NAT can inhibit apoptosis in HepG2 cells.     

A novel thioredoxin reductase inhibitor inhibits cell growth and induces apoptosis in HL-60 and K562 cells

Human thioredoxin reductase (TrxR) system is associated with cancer cell growth and anti-apoptosis process. Effects of 1,2-[bis(1,2-benzisoselenazolone-3(2H)-ketone)]ethane (BBSKE), a novel TrxR inhibitor, were investigated on human leukemia cell lines HL-60 and K562. BBSKE treatment induced cell growth inhibition and apoptosis in both cell lines. Apoptosis induced by BBSKE is through Bcl-2/Bax and caspase-3 pathways. Ehrlich's ascites carcinoma-bearing mice were used to investigate the anti-tumor effect of BBSKE in vivo. Tumor-bearing mice treated with BBSKE showed an increase of life span with a comparable effect to cyclophosphamide (CTX). These results suggest a potential usage of BBSKE as a therapeutic agent against non-solid tumors.     

Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200∼250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats. Project supported by Department of Biochemistry, Faculty of Medicine, UKM Medical Center, Universiti Kebangsaan Malaysia, and the Malaysian Ministry of Science and Technological Innovation (MOSTI)     

Protective effect of recombinant Lactobacillus plantarum against H2O2-induced oxidative stress in HUVEC cells

This study probed the protective effect of recombinant Lactobacillus plantarum against hydrogen peroxide(H_2O_2)-induced oxidative stress in human umbilical vein endothelial cells(HUVECs). We constructed a new functional L. plantarum(NC8-p SIP409-alr-angiotensin-converting enzyme inhibitory peptide(ACEIP)) with a double-gene-labeled non-resistant screen as an expression vector. A 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2 H-tetrazolium bromide(MTT) colorimetric assay was carried out to determine the cell viability of HUVEC cells following pretreatment with NC8-p SIP409-alr-ACEIP. Flow cytometry(FCM) was used to determine the apoptosis rate of HUVEC cells. Cysteinyl aspartate specific proteinase(caspase)-3/8/9 activity was also assayed and western blotting was used to determine protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2-associated X protein(Bax), inducible nitric oxide synthase(i NOS), nicotinamide adenine dinucleotide phosphate oxidase 2(gp91 phox), angiotensin II(Ang II), and angiotensin-converting enzyme 2(ACE2), as well as corresponding indicators of oxidative stress, such as reactive oxygen species(ROS), mitochondrial membrane potential(MMP), malondialdehyde(MDA),and superoxide dismutase(SOD). NC8-p SIP409-alr-ACEIP attenuated H_2O_2-induced cell death, as determined by the MTT assay. NC8-p SIP409-alr-ACEIP reduced apoptosis of HUVEC cells by FCM. In addition, compared to the positive control, the oxidative stress index of the H_2O_2-induced HUVEC(Hy-HUVEC), which was pretreated by NC8-p SIP409-alr-ACEIP, i NOS,gp91 phox, MDA, and ROS, was decreased obviously; SOD expression level was increased; caspase-3 or-9 was decreased, but caspase-8 did not change; Bcl-2/Bax ratio was increased; permeability changes of mitochondria were inhibited; and loss of transmembrane potential was prevented. Expression of the hypertension-related protein(Ang II protein) in HUVEC cells protected by NC8-p SIP409-alr-ACEIP decreased and expression of ACE2 protein increased. These plantarum results suggested that NC8-p SIP409-alr-ACEIP protects against H_2O_2-induced injury in HUVEC cells. The mechanism for this effect is related to enhancement of antioxidant capacity and apoptosis.     

顺铂联合热处理对术中回收血红细胞及其中混杂的肝肿瘤细胞株(HepG2)的影响（英文）

目的:研究离体热处理和顺铂联合热处理对术中回收血红细胞功能的影响及其中混杂的肝肿瘤细胞株(HepG2)的杀灭作用。创新点:(1)采用多种评价指标研究了不同时间离体热处理对术中回收血中混杂的HepG2的杀灭作用及对红细胞的影响,并确定了对红细胞安全且能有效杀灭HepG2的离体热处理时间。(2)从多个角度评价了离体顺铂联合热处理对术中回收血红细胞的影响及对其中混杂的HepG2的杀灭作用,确定了该方案中对红细胞安全且能有效去除HepG2的顺铂浓度。方法:采用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)、5-乙炔基-2’脱氧尿嘧啶核苷(EdU)和平板克隆形成评估HepG2的细胞存活率、DNA复制率和克隆形成能力(图1和3);从红细胞渗透脆性、携氧能力(2,3-二磷酸甘油酸(2,3-DPG)、半饱和氧分压(P50))、能量代谢(Na+-K+-ATPase、pH)、膜完整性(游离血红蛋白(Hb)、血清K+和Na+浓度、细胞膜磷脂酰丝氨酸外翻比例)等角度评估红细胞功能(图2和4;表3)。结论:肝肿瘤术中回收血经离体顺铂联合热处理(42°C,50μg/ml)60min后,能有效清除其中混杂的HepG2,但对红细胞无显著影响,值得体内进一步研究顺铂热处理有效应用于肿瘤手术自体血液回输的安全方案。     

Hydroxychavicol,a polyphenol from Piper betle leaf extract,induces cell cycle arrest and apoptosis in TP53-resistant HT-29 colon cancer cells

This study aims to elucidate the antiproliferative mechanism of hydroxychavicol(HC).Its effects on cell cycle,apoptosis,and the expression of c-Jun N-terminal kinase(JNK)and P38 mitogen-activated protein kinase(MAPK)in HT-29 colon cancer cells were investigated.HC was isolated from Piper betle leaf(PBL)and verified by high-performance liquid chromatography(HPLC),nuclear magnetic resonance(NMR),and gas chromatography-mass spectrometry(GC-MS).The cytotoxic effects of the standard drug 5-fluorouracil(5-FU),PBL water extract,and HC on HT-29 cells were measured after 24,48,and 72 h of treatment.Cell cycle and apoptosis modulation by 5-FU and HC treatments were investigated up to 30 h.Changes in phosphorylated JNK(pJNK)and P38(pP38)MAPK expression were observed up to 18 h.The half maximal inhibitory concentration(IC₅₀)values of HC(30μg/mL)and PBL water extract(380μg/mL)were achieved at 24 h,whereas the IC₅₀of 5-FU(50μmol/L)was obtained at 72 h.Cell cycle arrest at the G0/G1 phase in HC-treated cells was observed from12 h onwards.Higher apoptotic cell death in HC-treated cells compared to 5-FU-treated cells(P<0.05)was observed.High expression of pJNK and pP38 MAPK was observed at 12 h in HC-treated cells,but not in 5-FU-treated HT-29 cells(P<0.05).It is concluded that HC induces cell cycle arrest and apoptosis of HT-29 cells,with these actions possibly mediated by JNK and P38 MAPK.     

Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici

The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus ofGlomus intraradices and/or infection with pathogenic strain ofPhytophthora capsici, and the biological control effect ofG. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated withG. intraradices (Gi), (2) plants pre-inoculated withG. intraradices and then infected withP. capsici (Gi+Pc). (3) plants infected withP. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection ofP. capsici was completely eliminated by pre-inoculation with antagonisticG. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45000, 53000 and 114000) were present in Pc-treated roots, while two major bands (53000 and 114000) and one minor band (45000) were present in spectra of Gi+Pc-treated roots, the 45000 POD isozyme was significantly suppressed byG. intraradices, suggesting that the 45000 POD isozyme was induced by the pathogen infection but not induced by the antagonisticG. intraradices. A 60000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonisticG. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected byP. capsici. The results suggested thatG. intraradices is a potentially effective protection agent againstP. capsici. Project supported by Korea Science and Engineering Foundation (KOSEF) through the Agricultural Plants Stress Research Center (APSRC) at Chonnam National University, Korea     

新显色剂5-(8-喹啉偶氮)-2,3-二羟基吡啶分光光度法测定微量钴

用作者合成的嘶试剂5-(8-喳啉偶氮)-2,3-二羟基吡啶作显色剂,以分光光度法测定微量钴,在PH9.3的硼砂缓冲溶液中,配合物的最大吸收波长在624nm处,钴量在0～20μg/25ml范围内符合比尔定律,表观摩尔吸光系数为9.0×10~4L·10mol(-1)·cm(-1)。方法简便、快速,应用于维生素B_(12)和镍盐中钴的测定,获得满意结果。     

Response of ATP sulfurylase and serine acetyltransferase towards cadmium in hyperaccumulator Sedum alfredii Hance

We studied the responses of the activities of adenosine-triphosphate (ATP) sulfurylase (ATPS) and serine acetyltransferase (SAT) to cadmium (Cd) levels and treatment time in hyperaccumulating ecotype (HE) Sedum alfredii Hance, as compared with its non-hyperaccumulating ecotype (NHE). The results show that plant growth was inhibited in NHE but promoted in HE when exposed to high Cd level. Cd concentrations in leaves and shoots rapidly increased in HE rather than in NHE, and they became much higher in HE than in NHE along with increasing treatment time and Cd supply levels. ATPS activity was higher in HE than in NHE in all Cd treatments, and increased with increasing Cd supply levels in both HE and NHE when exposed to Cd treatment within 8 h. However, a marked difference of ATPS activity between HE and NHE was found with Cd treatment for 168 h, where ATPS activity increased in HE but decreased in NHE. Similarly, SAT activity was higher in HE than in NHE at all Cd treatments, but was more sensitive in NHE than in HE. Both ATPS and SAT activities in NHE leaves tended to decrease with increasing treatment time after 8 h at all Cd levels. The results reveal the different responses in sulfur assimilation enzymes and Cd accumulation between HE and NHE. With increasing Cd stress, the activities of sulfur assimilation enzymes (ATPS and SAT) were induced in HE, which may contribute to Cd accumulation in the hyperaccumulator Sedum alfredii Hance. Project supported by the National Natural Science Foundation of China (No. 30630046) and the Hi-Tech Research and Development Program (863) of China (No. 2006AA06Z386), and the Program for Changjiang Scholars and Innovative Research Team in University, China (No. IRT0536)     

HER-2 overexpression and survival in colorectal cancer: a meta-analysis

Objective

Numerous studies examining the relationship between human epidermal growth factor receptor 2 (HER-2) overexpression and survival in patients with colorectal cancer (CRC) have yielded controversial results. We therefore performed a meta-analysis more precisely to estimate its prognostic value.

Methods

Published studies investigating the effect of HER-2 overexpression on CRC survival were identified; the hazard ratios (HRs) and their corresponding 95% confidence intervals (95% CIs) were pooled in terms of disease-specific or overall survival.

Results

Eleven studies were included in the meta-analysis. The pooled data showed that HER-2 overexpression was negatively related to CRC survival (HR=1.10, 95% CI: 0.77–1.44). Subgroup analyses regarding test method and study quality also demonstrated little association between HER-2 overexpression and CRC survival (HR=0.89, 95% CI: 0.50–1.29; HR=0.90, 95% CI: 0.43–1.37, respectively).

Conclusions

Regardless of several limitations, our study suggested that HER-2 overexpression probably had little impact on CRC survival.     

Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)

The effects of CO₂ enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO₂ concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO₂ concentration, N concentration, and CO₂×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO₂. However, at 20 mmol N/L, elevated CO₂ had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO₂ concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO₂ concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO₂ condition. Project (No. 2007CB109305) supported by the National Basic Research Program (973) of China     

Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways

Mesenchymal stem cell(MSC)transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90)against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Apoptosis was assessed by Hoechst 33258nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4)and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2)was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,totaI-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.     

Relationships between changes of kernel nutritive components and seed vigor during development stages of F1 seeds of sh 2 sweet corn

The changes of kernel nutritive components and seed vigor in F₁ seeds of sh ₂ sweet corn during seed development stage were investigated and the relationships between them were analyzed by time series regression (TSR) analysis. The results show that total soluble sugar and reducing sugar contents gradually declined, while starch and soluble protein contents increased throughout the seed development stages. Germination percentage, energy of germination, germination index and vigor index gradually increased along with seed development and reached the highest levels at 38 d after pollination (DAP). The TSR showed that, during 14 to 42 DAP, total soluble sugar content was independent of the vigor parameters determined in present experiment, while the reducing sugar content had a significant effect on seed vigor. TSR equations between seed reducing sugar and seed vigor were also developed. There were negative correlations between the seed reducing sugar content and the germination percentage, energy of germination, germination index and vigor index, respectively. It is suggested that the seed germination, energy of germination, germination index and vigor index could be predicted by the content of reducing sugar in sweet corn seeds during seed development stages. Project supported by the National Natural Science Foundation of China (No. 30370911) and Education Department of Zhejiang Province, China (No. 20070147)     

试析李大钊与研究系的诀别宣言——《别泪》

在李大钊一生中,曾与研究系发生密切关系,他留学日本有赖于研究系的资助,但思想迅速发展中的李大钊已与研究系的政治理念产生根本分歧。《别泪》一文既是他对研究系的诚恳忠告,也是其坚定政治理念的宣言。     

QTL analysis of flag leaf in barley (Hordeum vulgare L.) for morphological traits and chlorophyll content

To understand genetic patterns of the morphological and physiological traits in flag leaf of barley, a double haploid (DH) population derived from the parents Yerong and Franklin was used to determine quantitative trait loci (QTL) controlling length, width, length/width, and chlorophyll content of flag leaves. A total of 9 QTLs showing significantly additive effect were detected in 8 intervals on 5 chromosomes. The variation of individual QTL ranged from 1.9% to 20.2%. For chlorophyll content expressed as SPAD value, 4 QTLs were identified on chromosomes 2H, 3H and 6H; for leaf length and width, 2 QTLs located on chromosomes 5H and 7H, and 2 QTLs located on chromosome 5H were detected; and for length/width, 1 QTL was detected on chromosome 7H. The identification of these QTLs associated with the properties of flag leaf is useful for barley improvement in breeding programs. Project supported by the National Natural Science Foundation of China (No. 30630047) and the Project on Absorption of Intellects by Institutions of Higher Education for Academic Disciplinary Innovations (the 111 Project) (No. B06014), China     

恶之花——《洛丽塔》的亨伯特与《黑暗之地》的阿尔比恩之比较

尖锐形式的恶是文学的表现。《洛丽塔》与《黑暗之地》这两部小说都用第一人称诚实地交流表达出对恶的严格道德上的认识,其中的主人公都涉及父女乱伦与强奸,在怪癖、丑陋的变态与病态空间里讨论人们尚不熟悉的恶的美学,表达了作者不同的创作主题。纳博科夫通过亨伯特与洛丽塔之间的畸形恋情描写探索了伦理道德世界的复杂人性;格伦维尔创造阿尔比恩的恶的形象充分说明了男权话语霸权对男女双方造成的身心伤害。     

《老子》的象喻言道方式及其诗学意义

面对"道"难以言明的困境,《老子》采用了"以象言道"的方式。"象喻"是《老子》特殊的言道方式,具体表现为:取譬引喻,以水、谷等自然之"象"形容"道";执象悟道,由草木、婴儿等"象"体悟"道";以物观物,通过对"象"的整体直观抵达"道"之本质。这种言道方式是诗性的,对后世文学创作与文学批评产生了极其重要的影响,催生了意象论及"以象喻文"话语方式,开启了对澄明本真之境的审美追求。     

Positive temperature coefficient of resistivity effects of semiconducting （Bi（1/2）Na（1/2））TiO3-CaTiO3-BaTiO3 ceramics sintered in air atmosphere

Y^3＋-doped （Bi 1/2 Na 1/2） TiO 3-CaTiO 3-BaTiO 3 （BNCBT） positive temperature coefficient of resistivity （PTCR） ceramics sintered in air atmosphere were investigated in this study. （Bi 1/2 Na 1/2） TiO 3 （BNT） component can remarkably increase the onset temperature T c of PTCR ceramics with the expense of the resistivity R 25 increase. CaTiO 3 （9–27 mol%） component can decrease the resistivity, and adjust the effects of BNT phase on the T c point. For the sample containing 3 mol% CaTiO 3 , T c raises from 122 ℃ to 153 ℃ when only 0.6 mol% BNT added, while for the ones with higher CaTiO 3 content （9–27 mol%）, T c is only increased by a rate of 8–9℃/1.0 mol% BNT. The effects of BNT and CaTiO 3 components on R25/Rmin （negative temperature coefficient effect） are also discussed.