PTEN inhibitor bisperoxovanadium protects against noise-induced hearing loss

Studies have shown that phosphatase and tensin homolog deleted on chromosome ten(PTEN)participates in the regulation of cochlear hair cell survival.Bisperoxovanadium protects against neurodegeneration by inhibiting PTEN expression.However,whether bisperoxovanadium can protect against noise-induced hearing loss and the underlying mechanism remains unclear.In this study,we established a mouse model of noise-induced hearing loss by exposure to 105 dB sound for 2 hours.We found that PTEN expression was increased in the organ of Corti,including outer hair cells,inner hair cells,and lateral wall tissues.Intraperitoneal administration of bisperoxovanadium decreased the auditory threshold and the loss of cochlear hair cells and inner hair cell ribbons.In addition,noise exposure decreased p-PI3K and p-Akt levels.Bisperoxovanadium preconditioning or PTEN knockdown upregulated the activity of PI3K-Akt.Bisperoxovanadium also prevented H_(2)O_(2)-induced hair cell death by reducing mitochondrial reactive oxygen species generation in cochlear explants.These findings suggest that bisperoxovanadium reduces noise-induced hearing injury and reduces cochlear hair cell loss.

ROCKⅡ与子痫前期发病的关系

为了解ROCKⅡ与子痫前期发病的关系,查阅国内外文献并对文献进行整理,发现ROCKⅡ在子痫前期发病过程中起一定作用,现就Rho/ROCK信号传导通路与妊娠的关系做一综述。

MYH基因变异与散发性大肠癌发病风险的初步研究

背景与目的：初步探讨MYH（MutY homologue，MYH）基因的变异与散发性大肠癌发病风险的关系。材料与方法：应用变性高效液相色谱（denaturing high performance liquid chromatography，DHPLC）和测序技术，对140例大肠癌患者及280名正常对照人群的MYH基因16个外显子区域中的7个（外显子1、7、9、11、13、14和16）区域进行变异筛查，用SPSS统计软件进行数据分析。结果：Exon1区域的变异位点为Exonl-316 G〉A、Exonl-292 G〉A和Intronl＋11 C〉T，3者同时出现在所有变异样本中，且病例组变异危险性均为对照组的8．16倍（P=0．04；OR=8．16，95％C／为1．01—203．70）；Exon16区域的变异为nt1678—80delGTF，病例组中直肠癌患者的变异危险性为结肠癌患者的7．18倍（P=0．04；OR=7．18，95％C／为1．102～165）；Exon11区域查出4例Intron10—2A〉G变异；Exon13区域筛查出2例In．on13＋12C〉T变异；Exon14区域筛查出1种错义变异，即Exon14＋74T〉A，P．V463E；Exon7和Exon9区域未筛查出任何变异。结论：MYH变异可能会增加结直肠癌发病风险，应进行监测管理；未筛查到高加索人群中最常见的Exon7区域的变异，提示人种之间变异存在差别。

EZH2 and STAT6 expression profiles are correlated with colorectal cancer stage and prognosis

AIM: To investigate the role of enhancer of zeste homologue 2 (EZH2) and STAT6 immunohistochemistry in the evaluation of clinical stages and prognosis of colorectal cancer (CRC). METHODS: The expression patterns were examined by immunohistochemistry in both tumor and adjacent non-neoplastic tissues of 119 CRC patients who underwent operation during the time period from 2002 to 2004. RESULTS: The positive rates of EZH2 and STAT6 in CRC cases were 69.7% (83 of 119) and 60.5% (72 of 119), respectively, and there was signifi cant differ-ence when compared with tumor adjacent non-neoplastic tissues (P < 0.05). In all CRC cases, patientswith EZH2-positive, or STAT6-positive expression had lower survival rates than those with EZH2-negative or STAT6-negative expression (P = 0.002 and P = 0.005, respectively). Co-expression of EZH2 and STAT6 showed signifi cantly higher levels in CRC cases of high clinical TNM stages (P = 0.001), and the expression of STAT6 was also correlated with lymph node metastasis and distant metastasis (P = 0.001 and P = 0.016, respectively). Multivariate analysis revealed that EZH2 expression was an independent prognostic indicator of CRC (P = 0.039). CONCLUSION: EZH2 and STAT6 expressions have significant values in distinguishing clinical stages of CRC and predicting the prognosis of the patients.

Nerve growth factor pretreatment against glutamate-induced hippocampal neuronal injury Action mechanism of phosphatase and tensin homologue deleted on chromosome 10

BACKGROUND： Nerve growth factor （NGF） attenuates glutamate-induced injury to hippocampal neurons, and the human tumor suppressor gene phosphatase and tensin homologue deleted on chromosome 10 （PTEN） promotes neuronal apoptosis. However, effects of PTEN in NGF-mediated neuroprotection against glutamate excitotoxicity remain poorly understood. OBJECTIVE： To investigate the relationship between NGF inhibition of glutamate-induced injury and PTEN. DESIGN, TIME AND SE＇I＇rlNG： The randomized, controlled, in vitro study was performed at the Department of Pathophysiology, Medical School of Nantong University, China from October 2007 to March 2008. MATERIALS： Glutamate, NGF, 4, 6-diamidino-2-phenyl-indolediacetate, 3-[4, 5-dimethylthiazol-2-yl]- 2, 5-diphenyl tetrazoliumbromide （M-I-F）, and lactate dehydrogenase kit （Sigma, USA）, fluorescence microscope and inverted phase contrast microscope （Olympus, Japan） were used in this study. METHODS： Hippocampal neurons were obtained from newborn （〈 24 hours） Sprague Dawley rats and cultured for 7 days. The control group was not treated with any intervention factor, the glutamate group was treated with glutamate （0.2 mmol/L）, and NGF groups were treated with NGF （10, 50, 100, and 200 μg/L, respectively） prior to glutamate treatment. MAIN OUTCOME MEASURES： The MTT and lactate dehydrogenase assays were applied to evaluate viability of hippocampal neurons. Morphological changes in hippocampal neurons were observed using an inverted phase-contrast microscope, and neuronal apoptosis was detected by 4, 6-diamidino-2- phenyl-indolediacetate staining. PTEN mRNA and protein expression were measured by reverse transcription-polymerase chain reaction and Western blot analysis, respectively. RESULTS： Glutamate （0.2 mmol/L） induced significantly decreased neuronal viability and greater lactate dehydrogenase efflux compared with the control group （P 〈 0.01）. However, compared with the glutamate group, cell viability significantly increased and lactate dehydrogenase efflux decreased in the NGF group with increasing NGF concentrations （P 〈 0.05 or P 〈 0.01）. The apoptotic ratio and PTEN mRNA and protein expression decreased in the NGF group compared with the glutamate group （P 〈 0.01）. CONCLUSION： Pretreatment with NGF exerted neuroprotective effects against glutamate-induced injury, partially through inhibition of PTEN expression and neuronal apoptosis.

Promoter methylation status of hMLH1,MGMT,and CDKN2A/p16 in colorectal adenomas

AIM:To investigate aberrant DNA methylation of CpG islands and subsequent low-or high-level DNA microsatellite instability(MSI)which is assumed to drive colon carcinogenesis. METHODS:DNA of healthy individuals,adenoma(tu-bular or villous/tubulovillous)patients,and colorectal carcinoma patients who underwent colonoscopy was used for assessing the prevalence of aberrant DNA methylation of human DNA mismatch repair gene mutator L homologue 1(hMLH1),Cyclin-dependent kinase inhibitor 2A(CDKN2A/p16),and O-6-methylguanine DNA methyltransferase(MGMT),as well as their rela- tion to MSI. RESULTS:The frequency of promoter methylation for each locus increased in the sequence healthy tissue/adenoma/carcinoma.MGMT showed the highest frequency in each group.MGMT and CDKN2A/p16 presented a statistically significant increase in promoter methylation between the less and more tumorigenic forms of colorectal adenomas(tubular vs tubullovillous and villous adenomas).All patients with tubulovillous/villous adenomas,as well as all colorectal cancer patients,showed promoter methylation in at least one of the examined loci.These findings suggest a potentially crucial role for methylation in the polyp/adenoma to cancer progres- sion in colorectal carcinogenesis.MSI and methylation seem to be interdependent,as simultaneous hMLH1, CDKN2A/p16,and MGMT promoter methylation was present in 8/9 colorectal cancer patients showing the MSI phenotype. CONCLUSION:Methylation analysis of hMLH1,CD- KN2A/p16,and MGMT revealed specific methylation profiles for tubular adenomas,tubulovillous/villous adenomas,and colorectal cancers,supporting the use of these alterations in assessment of colorectal tumorigenesis.

Effects and mechanism of adenovirus-mediated phosphatase and tension homologue deleted on chromosome ten gene on collagen deposition in rat liver fibrosis

AIM To evaluate the effects of phosphatase and tension homologue deleted on chromosome ten(PTEN) gene on collagen metabolism in hepatic fibrosis and the underlying mechanisms.METHODS rat primary hepatic stellate cells(HSCs) and human LX-2 cells were transfected with adenovirus containing c DNA constructs encoding wild-type PTEN(Ad-PTEN), PTEN mutant G129 E gene(Ad-G129E), and r NA interference constructs targeting the PTEN sequence PTEN short hairpin r NA to up-regulate and downregulate the expression of PTEN. HSCs were assayed using fluorescent microscopy, real-time polymerase chain reaction, and western blotting. Moreover, a CCl_4-induced rat hepatic fibrosis model was established to investigate the in vivo effects. Hematoxylin and eosin, and Masson's trichrome were used to assess the histological changes. The expression of collagen Ⅰ and Ⅲ was assessed using immunohistochemistry and western blot analysis.RESULTS Elevated expression of PTEN gene reduced serum levels of alanine transaminase and aspartate transaminase, decreased collagen deposition in the liver, and reduced hepatocyte necrosis. In contrast, knockdown of PTEN expression had an opposite effect, such as increased collagen deposition in the liver, and was molecularly characterized by the increased expression of matrix metalloproteinase(MMP)-13(P < 0.01) and MMP-2(P < 0.01), as well as decreased expression of the tissue inhibitor of metalloproteinase(TIMP)-1(P < 0.01) and TIMP-2(P < 0.01).CONCLUSION These data indicated that gene therapy using recombinant adenovirus encoding PTEN might be a novel way of treating hepatic fibrosis.

B7 homologue 3 as a prognostic biomarker and potential therapeutic target in gastrointestinal tumors

The most common digestive system(DS)cancers,including tumors of the gastrointestinal tract(GIT)such as colorectal cancer(CRC),gastric cancer(GC)and esophageal cancer(EC)as well as tumors of DS accessory organs such as pancreatic and liver cancer,are responsible for more than one-third of all cancerrelated deaths worldwide,despite the progress that has been achieved in anticancer therapy.Due to these limitations in treatment strategies,oncological research has taken outstanding steps towards a better understanding of cancer cell biological complexity and heterogeneity.These studies led to new molecular target-driven therapeutic approaches.Different in vivo and in vitro studies have revealed significant expression of B7 homologue 3(B7-H3)among the most common cancers of the GIT,including CRC,GC,and EC,whereas B7-H3 expression in normal healthy tissue of these organs was shown to be absent or minimal.This molecule is able to influence the biological behavior of GIT tumors through the various immunological and nonimmunological molecular mechanisms,and some of them are shown to be the result of B7-H3-related induction of signal transduction pathways,such as Janus kinase 2/signal transducer and activator of transcription 3,phosphatidylinositol 3-kinase/protein kinase B,extracellular signal-regulated kinase,and nuclear factor-κB.B7-H3 exerts an important role in progression,metastasis and resistance to anticancer therapy in these tumors.In addition,the results of many studies suggest that B7-H3 stimulates immune evasion in GIT tumors by suppressing antitumor immune response.Accordingly,it was observed that experimental depletion or inhibition of B7-H3 in gastrointestinal cancers improved antitumor immune response,impaired tumor progression,invasion,angiogenesis,and metastasis and decreased resistance to anticancer therapy.Finally,the high expression of B7-H3 in most common cancers of the GIT was shown to be associated with poor prognosis.In this review,we summarize the established data from different GIT cancer-related studies and suggest that the B7-H3 molecule could be a promising prognostic biomarker and therapeutic target for anticancer immunotherapy in these tumors.

Synthesis of Calix[4]pyrroles: A Class of New Molecular Receptor

Calix[4]pyrroles, as a class of new molecular receptor in the area of supramolecular chemistry, have displayed interesting anion and neutral substrate binding properties. In this paper, several new calix[4]pyrrole macrocycles were synthesised and characterized.

Axon regeneration induced by environmental enrichment-epigenetic mechanisms

Environmental enrichment is known to be beneficial for cognitive improvement.In many animal models of neurological disorders and brain injury,EE has also demonstrated neuroprotective benefits in neurodegenerative diseases and in improving recovery after stroke or traumatic brain injury.The exact underlying mechanism for these phenomena has been unclear.Recent findings have now indicated that neuronal activity elicited by environmental enrichment induces Ca2+influx in dorsal root ganglion neurons results in lasting enhancement of CREB-binding protein-mediated histone acetylation.This,in turn,increases the expression of pro-regeneration genes and promotes axonal regeneration.This mechanism associated with neuronal activity elicited by environmental enrichment-mediated pathway is one of several epigenetic mechanisms which modulate axon regeneration upon injury that has recently come to light.The other prominent mechanisms,albeit not yet directly associated with environmental enrichment,include DNA methylation/demethylation and N6-methyladenosine modification of transcripts.In this brief review,I highlight recent work that has shed light on the epigenetic basis of environmental enrichment-based axon regeneration,and discuss the mechanism and pathways involved.I further speculate on the implications of the findings,in conjunction with the other epigenetic mechanisms,that could be harness to promote axon regeneration upon injury.

Effect and Mechanism of Bushen Huoxue Recipe on Ovarian Reserve in Mice with Premature Ovarian Failure

The aim of the present study was to explore the effect and mechanism of Bushen Huoxue recipe（BHR） on ovarian reserve in mice with premature ovarian failure（POF）. Mice were divided into 3 groups： normal group, model group and BHR group. Intraperitoneal injection of cyclophosphamide was performed to create the POF model. Primordial follicular（PDF） number, ovarian wet weight, ovarian index, and estrous cycle were analyzed to evaluate the effect of BHR on POF. Meanwhile, the m RNA and protein level of Mouse Vasa Homologue（MVH） in the bone marrow, peripheral blood and ovary were detected, to explore the underlying mechanism of the treatment efficacy of BHR on ovarian reserve. By the time of BHR treatment for 28 days, BHR increased the PDF number and shortened the estrous cycle of POF mice. BHR also decreased the m RNA level of MVH in the bone marrow, and increased m RNA and protein level of MVH in the ovary of POF mice. Our results demonstrated a treatment efficacy of BHR on POF mice, and revealed that BHR might repair the dysfunction of germline stem cells in the bone marrow, and thus to improve the ovarian reserve and enhance the ovarian function of POF mice through neo-oogenesis.

Regulation of Floral Organ Identity in Arabidopsis by Ectopic Expression of OsMADS58

The ABCDE model has been described comprehensively to interpret the mechanism of floral organ development. In Arabidopsis, AGMAOUS was a well-studied class C gene encoding a transcription factor with MADS box, and its overexpression in Arabidopsis induced the transformation of sepals to carpels and petals to stamens. However, there is little knowledge about the function of OsMADS58, which was a homologue of AGMAOUS in rice. In our study, OsMADS58 driven by the UBIQUITIN promoter was ectopiely expressed in Arabidopsis., and carpel-like sepals, incomplete petals and stamens instead of petals were found in different transgenie plants according to different OsMADS58 mRNA expression levels. The phenotype of transgenic plant was similar to the AGMAOUS overexpression plant, suggesting that OsMADS58 might play an important role in flower development like AGMAOUS and they keep conserved function during evolution.

Molecular Cloning and Localization of Human Ataxin2-like Gene

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THE THEORETICAL STUDY ON INTERSECTION POINT RULE FOR HOMOLOGUES IN GAS CHROMATOGRAPHY

The intersection point rule for homologues in gas chromatography was discovered many years ago,now more and more application and development are occurring in recent years~[2-6], but there are few systemic theoretical studies.In this paper,based on the basic equation of reten- tion values in gas chromatography,we prove the intersection point rule of homologues from mathematics,study the factors affecting intersection point position,give the physical meaning of intersection point,and explain the experimental rules in references.

RhoC与胃癌的相关性研究进展

Rho是具有GTP酶活性的小G蛋白超家族成员,在细胞的信号转导通路中起重要作用,RhoC对肿瘤转移的作用尤为突出,被称为肿瘤侵袭转移的分子开关。胃癌侵袭转移是多基因协调作用的结果,本文就近年来RhoC在胃癌组织中侵袭转移的相关性研究作一综述。

Regulatory elements and transcriptional control of chicken vasa homologue(CVH)promoter in chicken primordial germ cells

Background： Primordial germ cells（PGCs）, the precursors of functional gametes, have distinct characteristics and exhibit several unique molecular mechanisms to maintain pluripotency and germness in comparison to somatic cells. They express germ cel-specific RNA binding proteins（RBPs） by modulating tissue-specific cis-and trans-regulatory elements. Studies on gene structures of chicken vasa homologue（CVH）, a chicken RNA binding protein, involved in temporal and spatial regulation are thus important not only for understanding the molecular mechanisms that regulate germ cel fate, but also for practical applications of primordial germ cells. However, very limited studies are available on regulatory elements that control germ cel-specific expression in chicken. Therefore, we investigated the intricate regulatory mechanism（s） that governs transcriptional control of CVH.Results： We constructed green fluorescence protein（GFP） or luciferase reporter vectors containing the various 5′ flanking regions of CVH gene. From the 5′ deletion and fragmented assays in chicken PGCs, we have identified a CVH promoter that locates at-316 to ＋275 base pair fragment with the highest luciferase activity. Additional y, we confirmed for the first time that the 5′ untranslated region（UTR） containing intron 1 is required for promoter activity of the CVH gene in chicken PGCs. Furthermore, using a transcription factor binding prediction, transcriptome analysis and siR NA-mediated knockdown,we have identified that a set of transcription factors play a role in the PGC-specific CVH gene expression.Conclusions： These results demonstrate that cis-elements and transcription factors localizing in the 5′ flanking region including the 5′ UTR and an intron are important for transcriptional regulation of the CVH gene in chicken PGCs. Final y,this information wil contribute to research studies in areas of reproductive biology, constructing of germ cel-specific synthetic promoter for tracing primordial germ cells as wel as understanding the transcriptional regulation for maintaining germness in PGCs.

Ectopic expression of a hyacinth AGL6 homolog caused earlier flowering and homeotic conversion in Arabidopsis

MADS-box genes are involved in floral organ development. Here we report that an AGL6(Agamous-like 6)-like MADS-box gene, HoAGL6, was isolated from Hyacinthus orientalis L. Expression pattern analy-sis demonstrated that HoAGL6 transcript was detected in inflorescence buds, tepals, carpels and ovules, but not in stamina, leaves or scales. Transgenic Arabidopsis plants ectopically expressing HoAGL6 exhibited novel phenotypes of significantly reduced plant size, extremely early flowering, and losing inflorescence indeterminacy. In addition, wide homeotic conversion of sepals, petals, and leaves into carpel-like or ovary structures, and disappearance or number reduction of stamens in 35S::HoAGL6 Arabidopsis plants were also observed. RT-PCR analysis indicated that the expressions of flowering time gene SOC1 and flower meristem identity gene LFY were significantly up-regulated in 35S::HoAGL6 transgenic Arabidopsis plants, and the expression levels of floral organ identity genes AG and SEP1 in leaves were also elevated. These results indicated that HoAGL6 was involved in the regulation of flower transition and flower organ formation.

Molecular cloning, chromosomal mapping and expression analysis of disease resistance gene homologues in rice(Oryza sativa L.)

Resistance-like sequences have been amplified from first strand cDNA and genomic DNA of rice by PCR using oligonucleotide primers designed from sequence motifs conserved between resistance genes of tobacco and Arabidopsis thaliana. 3 PCR clones, designated Osr1, Osr2 and Osr3 which were 98% identical in nucleotide sequence level, have been found to be significantly homologous to known plant resistance genes and all contained the conserved motifs of NBS-LRR type resistance genes, such as P-loop, kinase2a, kinase3a and transmembrane domain. Southern hybridization revealed that rice resistance gene homologues were organized as a cluster in the genome. RFLP mapping using a DH population derived from an indica/japonica cross (Zhaiyeqing 8/Jingxi 17) and an RFLP linkage map assigned two copies of Osr1 and one copy of Osr3 to the distal position of chromosome 12 where a blast resistance QTL has been mapped previously. Northern blot analysis showed that Osr1 gene was constitutively transcribed in rice leaves,

Role of phosphatase PTEN in the activation of extracellular signal-regulated kinases induced by estradiol in endometrial carcinoma cells

Objectives To study extracellular signal-regulated kinase (ERK) activation in the endometrial carcinoma cell line Ishikawa with stimulation by 17-β-estradiol, and to elucidate the role of phosphatase and tensin homologue (PTEN) and estrogen receptor (ER) subtype on the activation of ERKs.Methods Western blot was used to examine the expression of PTEN and PTEN (G129E) in Ishikawa cells after stable transfection as well as ERK activation in Ishikawa-EGFP, Ishikawa- PTEN and Ishikawa- PTEN (G129E) stimulated with various doses of 17-β-estradiol for different lengths of time. Western blot was also used for examining the expression of ERα and ERβ in NIH3T3 fibroblasts after transient transfection of pCXN2hERα and pCXN2hERβ. Then, ERK activation was examined after stimulation with 17-β-estradiol. Results 17-β-estradiol activated ERK cascades (mainly ERK2) in Ishikawa cells. The activation of ERK increased gradually as concentration of 17-β-estradiol also increased. The maximal activation of ERK2 took place 5 min after stimulation with 17-β-estradiol. The activation of ERK2 was inhibited markedly by PTEN, but not by PTEN (G129E). 17-β-estradiol activated ERK cascades in NIH3T3 fibroblasts after transient transfection of pCXN2hERα.Conclusions 17-β-estradiol activate ERK cascades in Ishikawa cells by integrating with ERα. Lipid phosphatase PTEN has an inhibitory role on the activation of ERK stimulated by 17-β-estradiol in Ishikawa cells.

Pollution characteristics and health risk assessment of benzene homologues in ambient air in the northeastern urban area of Beijing, China

Ambient benzene homologues were measured at a site in the northeastern urban area of Beijing, China, from August 24 to September 4, 2012 by SUMMA canister sampling followed by laboratory determination using cryogenic cold trap pre-concentration-GC-MS/FID, and their health risks were also assessed. Daily total benzene homologues ranged from 0.99 to 49.71 μg/m3 with an average of 11.98 μg/m3. Benzene homologues showed higher concentrations in the morning and evening than that at noontime. Comparison with previous studies revealed a trend of decrease for ambient benzene homologues probably due to the effective emission control in Beijing in recent years. Vehicular exhaust was the main source while volatilization of paints and solvents also made substantial contributions. Health risk assessment showed that BTEX （benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene） and styrene had no appreciable adverse non-cancer health risks for the exposed population, while benzene has potential cancer risk of 1.34E-05. Available data from cities in China all implied that benzene imposes relatively higher cancer risk on the exposed populations and therefore strict control measures should be taken to further lower ambient benzene levels in China.