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Articles by Z Zhang
Total Records ( 31 ) for Z Zhang
  Z Zhang , Q Li , F Liu , Y Sun and J. Zhang
 

The aim of this study was to investigate the prevention of diet-induced obesity by a high safflower oil diet and adipocytic gene expression in mice. Forty 3-week-old C57BL/6 mice were randomly divided into three groups: control group (CON, 5% lard + 5% safflower oil), high lard group (LAR, 45% lard + 5% safflower oil), and high safflower oil group (SAF, 45% safflower oil + 5% lard). After 10 weeks, 10 mice of the LAR group were switched to high safflower oil diet (LAR–SAF). Ten weeks later, glucose tolerance tests were performed by intraperitoneal injection of glucose. Circulating levels of lipid and insulin were measured and white adipose tissues were taken for gene chip and reverse transcriptase–polymerase chain reaction analysis. The LAR group showed higher body weight, adiposity index, insulin, and lipids than the CON group (P < 0.05). The body weight in the LAR–SAF group decreased after dietary reversal. The plasma biochemical profiles decreased in the LAR–SAF and SAF groups (P < 0.05) compared with those of the LAR group. The blood glucose level of the LAR–SAF group was reduced during intraperitoneal glucose tolerance test compared with that of the LAR group. The LAR–SAF group had lower levels of Orexin and Ghrelin gene expression, whereas the level of PPAR gene expression was significantly enhanced compared with that of the LAR group. So, the SAF diet can alter adipocytic adiposity-related gene expression and result in effective amelioration of diet-induced obesity.

  G Wang , X Zhou , Y Bai , Z Zhang and D. Zhao
 

Prion diseases are infectious and fatal neurodegenerative disorders. The cellular prion protein (PrPC) converting into misfolded isoform of prion protein (PrPSc) is responsible for prion disease infection. Immune system plays an important role in facilitating the spread of prion infections from the periphery to the central nervous system. Macrophages were considered associated with the transportation and replication of PrPSc. So, understanding the PrPC trafficking in macrophages is important to explore the transport mechanism for PrPSc. Here, we isolated exosomes from the culture medium of Ana-1 macrophage cell line and investigated the PrPC trafficked by exosomes and the interaction of PrPC with Hsp70 in secreted exosomes by western blotting, immunoelectron microscopy, and co-immunoprecipitation. The results showed that the isolated vesicles from the culture medium of macrophages were characterized by exosomes and bore PrPC. And PrPC bound to Hsp70 both in intracellular environment and secreted exosomes. In contrast, PrPC had no interaction with marker proteins of exosomes, Tag101 and Flotillin-1. These results suggested that PrPC present in extracellular space might be externalized through secreted exosomes from macrophages, and Hsp70 may play roles in the process of PrPC released via secreted exosomes.

  X Zhang , Z Zhang , G Chen , M Zhao , D Wang , Z Du , Y Xu and X. Yu
 

Previous studies have shown that histone deacetylase inhibitors (HDACis) can kill cancer cells. In addition, HDACis can induce mitotic catastrophe in cancer cells due to insufficient localization of chromosomal passenger complex (CPC) to the centromere. However, the mechanisms behind these phenomena remain unclear. In this study, we found that a HDACi, FK228, affected multiple epigenetic modification characteristics of the centromere, including enhanced acetylation of histone H3 lysine 9 (H3K9), decreased trimethylation of H3K9, and decreased phosphorylation of histone H3 serine 10 (H3S10) and centromere protein A (CENP-A). These epigenetic changes implied that H3K9 hyperacetylation inhibits the CPC recruitment, induces impaired centromere assembly and function, and eventually leads to aberrant mitosis. These data suggested that hypoacetylation of histone in the pericentromere is the most important landmark for recruiting CPC and leading to the mitotic catastrophe in HDACi-induced killing of cancer cells.

  L Zhang , X Jia , X Peng , Q Ou , Z Zhang , C Qiu , Y Yao , F Shen , H Yang , F Ma , J Wang and Z. Yuan
 

This paper presents an liquid chromatography (LC)/mass spectrometry (MS)-based metabonomic platform that combined the discovery of differential metabolites through principal component analysis (PCA) with the verification by selective multiple reaction monitoring (MRM). These methods were applied to analyze plasma samples from liver disease patients and healthy donors. LC–MS raw data (about 1000 compounds), from the plasma of liver failure patients (n = 26) and healthy controls (n = 16), were analyzed through the PCA method and a pattern recognition profile that had significant difference between liver failure patients and healthy controls (P < 0.05) was established. The profile was verified in 165 clinical subjects. The specificity and sensitivity of this model in predicting liver failure were 94.3 and 100.0%, respectively. The differential ions with m/z of 414.5, 432.0, 520.5, and 775.0 were verified to be consistent with the results from PCA by MRM mode in 40 clinical samples, and were proved not to be caused by the medicines taken by patients through rat model experiments. The compound with m/z of 520.5 was identified to be 1-Linoleoylglycerophosphocholine or 1-Linoleoylphosphatidylcholine through exact mass measurements performed using Ion Trap–Time-of-Flight MS and METLIN Metabolite Database search. In all, it was the first time to integrate metabonomic study and MRM relative quantification of differential peaks in a large number of clinical samples. Thereafter, a rat model was used to exclude drug effects on the abundance of differential ion peaks. 1-Linoleoylglycerophosphocholine or 1-Linoleoylphosphatidylcholine, a potential biomarker, was identified. The LC/MS-based metabonomic platform could be a powerful tool for the metabonomic screening of plasma biomarkers.

  S. L Zheng , V. L Stevens , F Wiklund , S. D Isaacs , J Sun , S Smith , K Pruett , K. E Wiley , S. T Kim , Y Zhu , Z Zhang , F. C Hsu , A. R Turner , J. E Johansson , W Liu , J. W Kim , B. L Chang , D Duggan , J Carpten , C Rodriguez , W Isaacs , H Gronberg and J. Xu
 

Single nucleotide polymorphisms (SNP) at 11q13 were recently implicated in prostate cancer risk by two genome-wide association studies and were consistently replicated in multiple study populations. To explore prostate cancer association in the regions flanking these SNPs, we genotyped 31 tagging SNPs in a ~110 kb region at 11q13 in a Swedish case-control study (Cancer of the Prostate in Sweden), including 2,899 cases and 1,722 controls. We found evidence of prostate cancer association for the previously implicated SNPs including rs10896449, which we termed locus 1. In addition, multiple SNPs on the centromeric side of the region, including rs12418451, were also significantly associated with prostate cancer risk (termed locus 2). The two groups of SNPs were separated by a recombination hotspot. We then evaluated these two representative SNPs in an additional ~4,000 cases and ~3,000 controls from three study populations and confirmed both loci at 11q13. In the combined allelic test of all four populations, P = 4.0 x 10–11 for rs10896449 at locus 1 and P = 1.2 x 10–6 for rs12418451 at locus 2, and both remained significant after adjusting for the other locus and study population. The prostate cancer association at these two 11q13 loci was unlikely confounded by prostate-specific antigen (PSA) detection bias because neither SNP was associated with PSA levels in controls. Unlike locus 1, in which no known gene is located, several putative mRNAs are in close proximity to locus 2. Additional confirmation studies at locus 2 and functional studies for both loci are needed to advance our knowledge on the etiology of prostate cancer. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1815–20)

  P Sun , Y Qiu , Z Zhang , J Wan , T Wang , X Jin , Q Lan , N Rothman and Z. l. Xia
 

DNA damage induced by benzene reactive metabolites is thought of as an important mechanism underlying benzene hematotoxicity and genotoxicity, and genetic variation in cell-cycle control genes may contribute to susceptibility to chronic benzene poisoning (CBP). Using a case-control study that included 307 benzene-poisoned patients and 299 workers occupationally exposed to benzene in south China, we aimed to investigate the association between genetic polymorphisms of p53 and p21 and the odds of CBP. To investigate whether benzene exposure may influence mRNA expression of p53 and p21 in benzene-exposed workers, we also chose 39 CBP workers, 38 occupationally benzene-exposure workers, and 37 nonexposure workers in the same region of China. PCR-restriction fragment length polymorphism technique was applied to detect polymorphisms of p53 (rs17878362, rs1042522, and rs1625895) and p21 (rs1801270 and rs1059234), and real-time PCR was applied to detect the quantity of gene mRNA expression. We found that p21 C98A variant genotypes (CA+AA) or C70T variant genotypes (CT+TT) were associated with decreased odds of CBP [odds ratio (OR), 0.51; 95% confidence interval (95% CI), 0.32-0.83, and OR, 0.53; 95% CI, 0.29-0.95, respectively. Further analysis showed the decreased odds of CBP in the subjects with p21 CC/AT diplotype (OR, 0.51; 95% CI, 0.30-0.85). In addition, p53 mRNA expression of CBP workers or benzene-exposure workers was significantly lower than that of nonexposure workers. Although these results require confirmation and extension, our results show that polymorphisms in p21 may be protective against the risk of CBP in the Chinese occupational population. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1821–8)

  Y Wang , Z Zhang , J. R Garbow , D. J Rowland , R. A Lubet , D Sit , F Law and M. You
 

Antitumor B (ATB) is a Chinese herbal mixture of six plants. Previous studies have shown significant chemopreventive efficacy of ATB against human esophageal and lung cancers. We have recently developed a new mouse model for lung squamous cell carcinomas (SCC). In this study, lung SCC mouse model was characterized using small-animal imaging techniques (magnetic resonance imaging and computed tomography). ATB decreased lung SCC significantly (3.1-fold; P < 0.05) and increased lung hyperplastic lesions by 2.4-fold (P < 0.05). This observation suggests that ATB can block hyperplasia from progression to SCC. ATB tissue distribution was determined using matrine as a marker chemical. We found that ATB is rapidly absorbed and then distributes to various tissues including the lung. These results indicate that ATB is a potent chemopreventive agent against the development of mouse lung SCCs.

  Y Wang , W Wen , Y Yi , Z Zhang , R. A Lubet and M. You
 

In the present study, we examined the effect of bexarotene (Targretin) and budesonide in the chemoprevention of small cell lung carcinoma using a lung-specific knockout model of Rb1 and p53. Upon treatment with bexarotene, tumor incidence, number, and load were significantly reduced (P < 0.05). Budesonide treatment trended to inhibition, but the effect was not statistically significant (P > 0.05). Immunohistochemical staining indicated that bexarotene treatment decreased cell proliferation and increased apoptosis in tumors. The Rb1/p53 gene–targeted mouse seems to be a valuable model for chemopreventive studies on human small cell lung cancer. Our results indicate that the retinoid X receptor agonist bexarotene may be a potent chemopreventive agent in this cancer type.

  Z Zhang , S Kobayashi , A. C Borczuk , R. S Leidner , T LaFramboise , A. D Levine and B. Halmos
 

Mitogen-activated protein kinase (MAPK) pathway signaling plays an important role in the majority of non-small-cell lung cancers (NSCLCs). In a prior microarray analysis of epidermal growth factor receptor (EGFR) inhibition in NSCLC cell lines, we noted that several dual specificity phosphatases (DUSPs) were among the most highly and immediately regulated genes. DUSPs act as natural terminators of MAPK signal transduction and therefore, we hypothesized a tumor suppressive role via feedback mechanisms. In the current study, we focus on the assessment of DUSP6, a cytoplasmic DUSP with high specificity for extracellular signal-regulated kinase (ERK). We demonstrate that DUSP6 expression tracks in tandem with ERK inhibition and that regulation of DUSP6 is mediated at the promoter level by ETS1, a well-known nuclear target of activated ERK. Small interfering RNA knockdown in DUSP6-high H441 lung cancer cells significantly increased ERK activation and cellular proliferation, whereas plasmid-driven overexpression in DUSP6-low H1975 lung cancer cells significantly reduced ERK activation and cellular proliferation and promoted apoptosis. Also, DUSP6 overexpression synergized with EGFR inhibitor treatment in EGFR-mutant HCC827 cells. Our results indicate that DUSP6 expression is regulated by ERK signaling and that DUSP6 exerts antitumor effects via negative feedback regulation, pointing to an important feedback loop in NSCLC. Further studies assessing the tumor suppressive role of DUSP6 and strategies aimed at modulation of its activity are warranted.

  A Zampetaki , L Zeng , A Margariti , Q Xiao , H Li , Z Zhang , A. E Pepe , G Wang , O Habi , E deFalco , G Cockerill , J. C Mason , Y Hu and Q. Xu
 

Background— Histone deacetylase 3 (HDAC3) is known to play a crucial role in the differentiation of endothelial progenitors. The role of HDAC3 in mature endothelial cells, however, is not well understood. Here, we investigated the function of HDAC3 in preserving endothelial integrity in areas of disturbed blood flow, ie, bifurcation areas prone to atherosclerosis development.

Methods and Results— En face staining of aortas from apolipoprotein E-knockout mice revealed increased expression of HDAC3, specifically in these branching areas in vivo, whereas rapid upregulation of HDAC3 protein was observed in endothelial cells exposed to disturbed flow in vitro. Interestingly, phosphorylation of HDAC3 at serine/threonine was observed in these cells, suggesting that disturbed flow leads to posttranscriptional modification and stabilization of the HDAC3 protein. Coimmunoprecipitation experiments showed that HDAC3 and Akt form a complex. Using a series of constructs harboring deletions, we found residues 136 to 206 of HDAC3 to be crucial in this interaction. Enforced expression of HDAC3 resulted in increased phosphorylation of Akt and upregulation of its kinase activity. In line with these findings, knockdown of HDAC3 with lentiviral vectors (shHDAC3) led to a dramatic decrease in cell survival accompanied by apoptosis in endothelial cells. In aortic isografts of apolipoprotein E-knockout mice treated with shHDAC3, a robust atherosclerotic lesion was formed. Surprisingly, 3 of the 8 mice that received shHDAC3-infected grafts died within 2 days after the operation. Miller staining of the isografts revealed disruption of the basement membrane and rupture of the vessel.

Conclusions— Our findings demonstrated that HDAC3 serves as an essential prosurvival molecule with a critical role in maintaining the endothelial integrity via Akt activation and that severe atherosclerosis and vessel rupture in isografted vessels of apolipoprotein E-knockout mice occur when HDAC3 is knocked down.

  R. C Laxton , Y Hu , J Duchene , F Zhang , Z Zhang , K. Y Leung , Q Xiao , R. S Scotland , C. P Hodgkinson , K Smith , J Willeit , C Lopez Otin , I. A Simpson , S Kiechl , A Ahluwalia , Q Xu and S. Ye
 

Rationale: Atherosclerotic lesions express matrix metalloproteinase (MMP)8, which possesses proteolytic activity on matrix proteins particularly fibrillar collagens and on nonmatrix proteins such as angiotensin (Ang) I.

Objective: We studied whether MMP8 plays a role in atherogenesis.

Methods and Results: In atherosclerosis-prone apolipoprotein E–deficient mice, inactivating MMP8 resulted in a substantial reduction in atherosclerotic lesion formation. Immunohistochemical examinations showed that atherosclerotic lesions in MMP8-deficient mice had significantly fewer macrophages but increased collagen content. In line with results of in vitro assays showing that Ang I cleavage by MMP8 generated Ang II, MMP8 knockout mice had lower Ang II levels and lower blood pressure. In addition, we found that products of Ang I cleavage by MMP8 increased vascular cell adhesion molecule (VCAM)-1 expression and that MMP8-deficient mice had reduced VCAM-1 expression in atherosclerotic lesions. Intravital microscopy analysis showed that leukocyte rolling and adhesion on vascular endothelium was reduced in MMP8 knockout mice. Furthermore, we detected an association between MMP8 gene variation and extent of coronary atherosclerosis in patients with coronary artery disease. A relationship among MMP8 gene variation, plasma VCAM-1 level, and atherosclerosis progression was also observed in a population-based, prospective study.

Conclusions: These results indicate that MMP8 is an important player in atherosclerosis.

  A. E Pepe , Q Xiao , A Zampetaki , Z Zhang , A Kobayashi , Y Hu and Q. Xu
 

Rationale: Nuclear factor erythroid 2-related factor (Nrf)3, a member of the cap ‘N’ collar family of transcription factors that bind to the DNA-antioxidant responsive elements, is involved in reactive oxygen species balancing and in muscle precursor migration during early embryo development.

Objective: To investigate the functional role of Nrf3 in smooth muscle cell (SMC) differentiation in vitro and in vivo.

Methods and Results: Nrf3 was upregulated significantly following 1 to 8 days of SMC differentiation. Knockdown of Nrf3 resulted in downregulation of smooth muscle specific markers expression, whereas enforced expression of Nrf3 enhanced SMC differentiation in a dose-dependent manner. SMC-specific transcription factor myocardin, but not serum response factor, was significantly upregulated by Nrf3 overexpression. Strikingly, the binding of SRF and myocardin to the promoter of smooth muscle differentiation genes was dramatically increased by Nrf3 overexpression, and Nrf3 can directly bind to the promoters of SMC differentiation genes as demonstrated by chromatin immunoprecipitation assay. Moreover, NADPH-derived reactive oxygen species production during SMC differentiation was further enhanced by Nrf3 overexpression through upregulation of NADPH oxidase and inhibition of antioxidant signaling pathway. In addition, Nrf3 was involved in the endoplasmic reticulum stressor induced SMC differentiation.

Conclusion: Our findings demonstrate for the first time that Nrf3 has a crucial role in SMC differentiation from stem cells indicating that Nrf3 could be a potential target for manipulation of stem cell differentiation toward vascular lineage.

  J Du , J Xie , Z Zhang , H Tsujikawa , D Fusco , D Silverman , B Liang and L. Yue
 

Rationale: Cardiac fibrosis contributes to pathogenesis of atrial fibrillation (AF), which is the most commonly sustained arrhythmia and a major cause of morbidity and mortality. Although it has been suggested that Ca2+ signals are involved in fibrosis promotion, the molecular basis of Ca2+ signaling mechanisms and how Ca2+ signals contribute to fibrogenesis remain unknown.

Objective: To determine the molecular mechanisms of Ca2+-permeable channel(s) in human atrial fibroblasts, and to investigate how Ca2+ signals contribute to fibrogenesis in human AF.

Methods and Results: We demonstrate that the transient receptor potential (TRP) melastatin related 7 (TRPM7) is the molecular basis of the major Ca2+-permeable channel in human atrial fibroblasts. Endogenous TRPM7 currents in atrial fibroblasts resemble the biophysical and pharmacological properties of heterologous expressed TRPM7. Knocking down TRPM7 by small hairpin RNA largely eliminates TRPM7 current and Ca2+ influx in atrial fibroblasts. More importantly, atrial fibroblasts from AF patients show a striking upregulation of both TRPM7 currents and Ca2+ influx and are more prone to myofibroblast differentiation, presumably attributable to the enhanced expression of TRPM7. TRPM7 small hairpin RNA markedly reduced basal AF fibroblast differentiation. Transforming growth factor (TGF)-β1, the major stimulator of atrial fibrosis, requires TRPM7-mediated Ca2+ signal for its effect on fibroblast proliferation and differentiation. Furthermore, TGF-β1–induced differentiation of cultured human atrial fibroblasts is well correlated with an increase of TRPM7 expression induced by TGF-β1.

Conclusions: Our results establish that TRPM7 is the major Ca2+-permeable channel in human atrial fibroblasts and likely plays an essential role in TGF-β1–elicited fibrogenesis in human AF.

  A Margariti , A Zampetaki , Q Xiao , B Zhou , E Karamariti , D Martin , X Yin , M Mayr , H Li , Z Zhang , E De Falco , Y Hu , G Cockerill , Q Xu and L. Zeng
 

Rationale: Histone deacetylase (HDAC)7 is expressed in the early stages of embryonic development and may play a role in endothelial function.

Objective: This study aimed to investigate the role of HDAC7 in endothelial cell (EC) proliferation and growth and the underlying mechanism.

Methods and Results: Overexpression of HDAC7 by adenoviral gene transfer suppressed human umbilical vein endothelial cell (HUVEC) proliferation by preventing nuclear translocation of β-catenin and downregulation of T-cell factor-1/Id2 (inhibitor of DNA binding 2) and cyclin D1, leading to G1 phase elongation. Further assays with the TOPFLASH reporter and quantitative RT-PCR for other β-catenin target genes such as Axin2 confirmed that overexpression of HDAC7 decreased β-catenin activity. Knockdown of HDAC7 by lentiviral short hairpin RNA transfer induced β-catenin nuclear translocation but downregulated cyclin D1, cyclin E1 and E2F2, causing HUVEC hypertrophy. Immunoprecipitation assay and mass spectrometry analysis revealed that HDAC7 directly binds to β-catenin and forms a complex with 14-3-3 , , and proteins. Vascular endothelial growth factor treatment induced HDAC7 degradation via PLC-IP3K (phospholipase C–inositol-1,4,5-trisphosphate kinase) signal pathway and partially rescued HDAC7-mediated suppression of proliferation. Moreover, vascular endothelial growth factor stimulation suppressed the binding of HDAC7 with β-catenin, disrupting the complex and releasing β-catenin to translocate into the nucleus.

Conclusions: These findings demonstrate that HDAC7 interacts with β-catenin keeping ECs in a low proliferation stage and provides a novel insight into the mechanism of HDAC7-mediated signal pathways leading to endothelial growth.

  Z Yuan , H Pei , D. J Roberts , Z Zhang , J. S Rowlan , A. H Matsumoto and W. Shi
 

Background— Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit marked differences in neointimal formation after arterial injury when deficient in apolipoprotein E (apoE–/–) and fed a Western diet. Quantitative trait locus analysis was performed on an intercross between B6.apoE–/– and C3H.apoE–/– mice to determine genetic factors contributing to the phenotype.

Methods and Results— Female B6.apoE–/– mice were crossed with male C3H.apoE–/– mice to generate F1s, which were intercrossed to generate 204 male F2 progeny. At 10 weeks of age, F2s underwent endothelium denudation injury to the left common carotid artery. Mice were fed a Western diet for 1 week before and 4 weeks after injury and analyzed for neointimal lesion size, plasma lipid, and membrane cofactor protein (MCP)-1 levels. One significant quantitative trait locus, named Nih1 (61 cM; LOD score, 5.02), on chromosome 12 and a suggestive locus on chromosome 13 (35 cM; LOD score, 2.67) were identified to influence lesion size. One significant quantitative trait locus on distal chromosome 1 accounted for major variations in plasma non–high-density lipoprotein cholesterol and triglyceride levels. Four suggestive quantitative trait locis on chromosomes 1, 2, and 3 were detected for circulating MCP-1 levels. No correlations were observed between neointimal lesion size and plasma lipid levels or between lesion size and plasma MCP-1 levels.

Conclusions— Neointimal formation is controlled by genetic factors independent of those affecting plasma lipid levels and circulating MCP-1 levels in the B6 and C3H mouse model.

  W Shi , Z Zhang , M. H Chen , J. F Angle and A. H. Matsumoto
  Background—

C3H/HeJ (C3H) mice develop much smaller atherosclerotic lesions than C57BL/6 (B6) mice when deficient in apolipoprotein E (apoE–/–) or fed an atherogenic diet. The 2 strains differ in H2 haplotypes, with B6 having H2b and C3H having H2k. C3.SW-H2b/SnJ (C3.SW) is a congenic strain of C3H/HeJ in which H2k is replaced with H2b.

Methods and Results—

We performed bone marrow transplantation and found that atherosclerosis-resistant C3.SW.apoE–/– mice reconstituted with bone marrow from either C3.SW.apoE–/– or B6.apoE–/– mice after lethal irradiation had significantly larger atherosclerotic lesions than B6.apoE–/– mice receiving identical treatments and much larger lesions than C3H.apoE–/– mice reconstituted with syngeneic bone marrow. For syngeneic transplantation, C3.SW.apoE–/– mice exhibited a 21-fold increase in lesion size over C3H.apoE–/– mice (152 800±21 937 versus 7060±2290 µm2/section) and a near 4-fold increase over B6.apoE–/– mice (40 529±4675 µm2/section). C3.SW.apoE–/– mice reconstituted with syngeneic marrow exhibited enhanced lesion formation relative to those reconstituted with B6 marrow (152 800±21 937 versus 107 000±9374 µm2/section; P=0.067). Sublethal irradiation led to a 6-fold increase of lesion size in C3.SW.apoE–/– mice (9795±2804 versus 1550±607 µm2/section; P=0.008). Wild-type C3.SW mice reconstituted with apoE+/+ or apoE–/– bone marrow had significantly larger atherosclerotic lesions than C3H mice receiving identical treatments on an atherogenic diet.

Conclusions—

These results indicate that gene(s) within the H2 region have a dramatic impact on radiation-enhanced atherosclerosis, and their effect is conveyed partially through bone marrow–derived cells.

  M. J Fackler , A Rivers , W. W Teo , A Mangat , E Taylor , Z Zhang , S Goodman , P Argani , R Nayar , B Susnik , S Sukumar and S. A. Khan
 

Purpose: In a pilot study of women with pathologic nipple discharge (PND) undergoing ductoscopy, we tested quantitative assessment of gene promoter hypermethylation using quantitative multiplex methylation–specific PCR (QM-MSP) to enhance detection of duct carcinoma in situ (DCIS).

Experimental Design: Women with PND underwent ductoscopy; ducts with significant lesions were surgically resected (36 ducts in 33 women) and those with minimal findings were not (28 ducts in 16 women). QM-MSP was done on ductoscopy cell samples. Results were compared with cytology and tissue histology.

Results: Cells from ducts with significant lesions on ductoscopy had significantly higher levels of methylation than those with minimal findings. Furthermore, cells from ducts with DCIS displayed higher levels of methylation than those with benign lesions such as papilloma (P = 0.006); or ducts with minimal findings on ductoscopy (P = 0.0001). Cumulative RASSF1A, TWIST1, and HIN1 gene methylation accurately distinguished ducts with cancerous versus benign lesions (100% sensitivity, 72% specificity, and area under the curve of 0.91 according to receiving operating characteristic analyses). QM-MSP analysis was more informative than cytology (100% versus 29% sensitivity, respectively), for detecting DCIS. In a validation set of paraffin-embedded DCIS and papilloma samples from women presenting with PND, QM-MSP was significantly higher in DNA from DCIS than papilloma sections (P = 0.002).

Conclusion: The positive predictive value of ductoscopy was more than doubled (19% versus 47%) with the addition of QM-MSP, demonstrating the benefit of targeting ducts having both high methylation and significant abnormalities on ductoscopy for surgical excision. Future large-scale studies to validate this approach are needed.

  K. J McKernan , H. E Peckham , G. L Costa , S. F McLaughlin , Y Fu , E. F Tsung , C. R Clouser , C Duncan , J. K Ichikawa , C. C Lee , Z Zhang , S. S Ranade , E. T Dimalanta , F. C Hyland , T. D Sokolsky , L Zhang , A Sheridan , H Fu , C. L Hendrickson , B Li , L Kotler , J. R Stuart , J. A Malek , J. M Manning , A. A Antipova , D. S Perez , M. P Moore , K. C Hayashibara , M. R Lyons , R. E Beaudoin , B. E Coleman , M. W Laptewicz , A. E Sannicandro , M. D Rhodes , R. K Gottimukkala , S Yang , V Bafna , A Bashir , A MacBride , C Alkan , J. M Kidd , E. E Eichler , M. G Reese , F. M De La Vega and A. P. Blanchard
 

We describe the genome sequencing of an anonymous individual of African origin using a novel ligation-based sequencing assay that enables a unique form of error correction that improves the raw accuracy of the aligned reads to >99.9%, allowing us to accurately call SNPs with as few as two reads per allele. We collected several billion mate-paired reads yielding ~18x haploid coverage of aligned sequence and close to 300x clone coverage. Over 98% of the reference genome is covered with at least one uniquely placed read, and 99.65% is spanned by at least one uniquely placed mate-paired clone. We identify over 3.8 million SNPs, 19% of which are novel. Mate-paired data are used to physically resolve haplotype phases of nearly two-thirds of the genotypes obtained and produce phased segments of up to 215 kb. We detect 226,529 intra-read indels, 5590 indels between mate-paired reads, 91 inversions, and four gene fusions. We use a novel approach for detecting indels between mate-paired reads that are smaller than the standard deviation of the insert size of the library and discover deletions in common with those detected with our intra-read approach. Dozens of mutations previously described in OMIM and hundreds of nonsynonymous single-nucleotide and structural variants in genes previously implicated in disease are identified in this individual. There is more genetic variation in the human genome still to be uncovered, and we provide guidance for future surveys in populations and cancer biopsies.

  H. H Liu , P Lu , Y Guo , E Farrell , X Zhang , M Zheng , B Bosano , Z Zhang , J Allard , G Liao , S Fu , J Chen , K Dolim , A Kuroda , J Usuka , J Cheng , W Tao , K Welch , Y Liu , J Pease , S. A de Keczer , M Masjedizadeh , J. S Hu , P Weller , T Garrow and G. Peltz
 

Acetaminophen-induced liver toxicity is the most frequent precipitating cause of acute liver failure and liver transplant, but contemporary medical practice has mainly focused on patient management after a liver injury has been induced. An integrative genetic, transcriptional, and two-dimensional NMR-based metabolomic analysis performed using multiple inbred mouse strains, along with knowledge-based filtering of these data, identified betaine-homocysteine methyltransferase 2 (Bhmt2) as a diet-dependent genetic factor that affected susceptibility to acetaminophen-induced liver toxicity in mice. Through an effect on methionine and glutathione biosynthesis, Bhmt2 could utilize its substrate (S-methylmethionine [SMM]) to confer protection against acetaminophen-induced injury in vivo. Since SMM is only synthesized in plants, Bhmt2 exerts its beneficial effect in a diet-dependent manner. Identification of Bhmt2 and the affected biosynthetic pathway demonstrates how a novel method of integrative genomic analysis in mice can provide a unique and clinically applicable approach to a major public health problem.

  S Wang , Z Zhang , X Lin , D. S Xu , Y Feng and K. Ding
 

Ophiopogon japonicus is a traditional Chinese medicine used to treat cardiovascular disease. Recent studies have confirmed its beneficial properties, but not the mechanism of action. Herein, we investigate the anti-ischemic properties of a water-soluble β-d-fructan (MDG-1) from Ophiopogon japonicus, and assess the cytoprotective and proangiogenic effects of MDG-1. MDG-1 protects cardiomyocyte and microvascular endothelial cells (HMEC-1) against oxygen glucose deprivation (OGD)-induced cell death, as well as protect myocardial cells from ischemia-induced death occurring after coronary artery ligation in rats. Meanwhile, MDG-1 stimulates the differentiation of HMEC-1 cells into capillary-like structures in vitro and functions as a chemoattractant in migration assays, and promotes neovascularization in ischemic myocardium. In addition, MDG-1 upregulates sphingosine kinase 1 and sphingosine-1-phosphate (S1P) receptor 1 expression. Both MDG-1 and S1P induce basic fibroblast growth factor (bFGF) expression in HMEC-1 cells. Further study revealed that both MDG-1 and S1P induce Akt and ERK phosphorylation in a dose- and time-dependent manner, an effect that is attenuated by pre-treatment with either the Akt inhibitor wortmannin or the ERK inhibitor PD98059, and MDG-1 can also induce eNOS phosphorylation and increases in production of NO. These data indicate that MDG-1 presented remarkable anti-ischemic activity and protects cardiomyocyte and HMEC-1 cells from ischemia-induced cell damage by inducing S1P1 and bFGF cytoprotective and proangiogenic effects via the S1P/bFGF/Akt/ERK/eNOS signaling pathway.

  Z Xiao , W Zhao , B Yang , Z Zhang , H Guan and R. J. Linhardt
 

Porcine intestinal mucosa heparin was partially depolymerized by recombinant heparinase 1 (heparin lyase 1, originating from Flavobacterium heparinum and expressed in Escherichia coli) and then fractionated, leading to the isolation of 22 homogeneous oligosaccharides with sizes ranging from disaccharide to hexadecasaccharide. The purity of these oligosaccharides was determined by gel electrophoresis, strong anion exchange and reversed-phase ion-pairing high-performance liquid chromatography. The molecular mass of oligosaccharides was determined using electrospray ionization-mass spectrometry and their structures were elucidated using one- and two-dimensional nuclear magnetic resonance spectroscopy at 600 MHz. Five of the characterized oligosaccharides represent new compounds. The most prominent oligosaccharide comprises the common repeating unit of heparin, UA2S-[-GlcNS6S-IdoA2S-]n-GlcNS6S, where UA is 4-deoxy--l-threo-hex-4-eno-pyranosyluronic acid, GlcN is 2-deoxy-2-amino-d-glucopyranose, IdoA is l-idopyranosyluronic acid, S is sulfate and = 0–7. A second prominent heparin oligosaccharide motif corresponds to UA2S-[GlcNS6S-IdoA2S]n-GlcNS6S-IdoA-GlcNAc6S-GlcA-GlcNS3S6S (where n = 0–5 and GlcA is d-glucopyranosyluronic acid), a fragment of the antithrombin III binding site in heparin. The prominence of this second set of oligosaccharides and the absence of intact antithrombin III binding sites suggest that the -GlcNS3S6S-IdoA2S- linkage is particularly susceptible to heparinase 1.

  J Zheng , G Wang , G. Y Yang , D Wang , X Luo , C Chen , Z Zhang , Q Li , W Xu , Z Li and D. Wang
  Objective

This Phase II study was conducted to evaluate the activity and feasibility of a regimen of nedaplatin and 5-fluorouracil as induction chemotherapy, followed by intensity-modulated radiotherapy concurrent with chemotherapy in patients with locoregionally advanced nasopharyngeal carcinoma.

Methods

Patients received neoadjuvant chemotherapy comprised two cycles of 5-fluorouracil at 700 mg/m2/day administered on days 1–4 as continuous intravenous infusion and nedaplatin (100 mg/m2 administered i.v. over 2 h) given after the administration of 5-fluorouracil on day 1, repeated every 3 weeks, followed by intensity-modulated radiotherapy concurrent with nedaplatin. During intensity-modulated radiotherapy, nedaplatin was administered at a dose of 100 mg/m2 intravenous infusion on days 1, 22 and 43, given ~60 min before radiation.

Results

Fifty-nine (95.8%) of the 60 patients were assessable for response. Thirty-eight cases of complete response and 14 cases of partial response were confirmed after completion of chemoradiation, with the objective response rate of 86.7% (95% CI, 78.1–95.3%). The median follow-up period was 48 months (range, 30–62 months). The 3-year progression-free survival and overall survival were 75.0% (95% CI, 63.0–87.0%) and 85.5% (95% CI, 75.9–95.1%). No patient showed Grade 3 or higher renal dysfunction. The most commonly observed late effect was xerostomia, but the severity diminished over time, and the detectable xerostomia at 24 months was 10.2%. There were no treatment-related deaths during this study.

Conclusions

Neoadjuvant chemotherapy with nedaplatin and 5-fluorouracil followed by concomitant nedaplatin and intensity-modulated radiotherapy is an effective and safe treatment for Southern China patients affected by locoregionally advanced nasopharyngeal carcinoma.

  C Zhou , S Ren , S Zhou , L Zhang , C Su , Z Zhang , Q Deng and J. Zhang
  Objective

The purpose of the study was to investigate whether single-nucleotide polymorphisms of deoxyribonucleic acid repair gene excision repair cross-complementing group 1 at codon 118 and X-ray repair cross-complementing group 3 at codon 241 affected clinical outcomes in advanced non-small cell lung cancer patients receiving first-line platinum-based chemotherapy.

Methods

A total of 130 patients treated with platinum-based doublets were examined for genotyping of excision repair cross-complementing group 1 118 and X-ray repair cross-complementing group 3 241 in peripheral blood lymphocytes with the method of the TaqMan assay plus the real-time polymerase chain reaction method. Multivariate logistic or Cox's regression analyses were used to adjust for possible confounding variables.

Results

There were no differences in clinical characteristics among the different single-nucleotide polymorphisms. Overall response rate in the 130 patients was 20% with 85.4% of disease control rate. Followed up to 31 March 2008, there were 47 patients still alive. Overall survival was 15 months. No relationship was found between excision repair cross-complementing group 1 or X-ray repair cross-complementing group 3 single-nucleotide polymorphisms and tumor response to platinum-based chemotherapy. A significant correlation was found between excision repair cross-complementing group 1 118C/T single-nucleotide polymorphisms and survival (P = 0.003). In the multivariate model, the survival was highly related with excision repair cross-complementing group 1 118 C/T or T/T genotypes and tumor response to chemotherapy.

Conclusions

Overall survival was significantly improved in the patients with excision repair cross-complementing group 1 118 T/T or C/T treated by platinum-based chemotherapy.

  D Gu , M Wang , Z Zhang and J. Chen
 

Published data regarding the association between the apurinic/apyrimidinic endonuclease 1 (APE1) T1349G (Asp148Glu) polymorphism and cancer risk show inconclusive results. To derive a more precise estimation of the relationship, we performed a meta-analysis of 27 published studies that included 12 432 cancer cases and 17 349 controls. We used odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the strength of the associations. The overall results suggested that the variant genotypes were associated with a moderately increased risk of all cancer types (OR = 1.09, 95% CI = 1.01–1.18 for TG versus TT; OR = 1.08, 95% CI = 1.00–1.18 for GG/TG versus TT). In the stratified analyses, the risk remained for studies of colorectal cancer, European populations and population-based studies. Although some modest bias could not be eliminated, this meta-analysis supported that the APE1 T1349G polymorphism is a low-penetrance risk factor for cancer development.

  B Peng , L Cao , W Wang , L Xian , D Jiang , J Zhao , Z Zhang , X Wang and L. Yu
 

Matrix metalloproteinase (MMP) 1 and MMP3 are enzymes that degrade the extracellular matrix and have been implicated to play an important role in cancer development. Many studies have been carried out on the association between polymorphisms of MMP1 –1607 1G>2G and MMP3 –1171 5A>6A and cancer risk. However, results from these studies remain inconclusive. Here, we performed a meta-analysis of >38 000 subjects to better assess the purported associations. For MMP1, –1607 2G/2G genotype carriers were found to have an increased risk of colorectal cancer [2G/2G versus 2G/1G + 1G/1G, odds ratio (OR) = 1.48, 95% confidence interval (CI) (1.26–1.74), Pheterogeneity = 0.066, I2 = 49.3%], head and neck cancer [2G/2G versus 2G/1G + 1G/1G, OR = 1.61, 95% CI (1.26–2.07), Pheterogeneity = 0.002, I2 = 64.7%] and renal cancer [2G/2G versus 2G/1G + 1G/1G, OR = 1.82, 95% CI (1.38–2.39), Pheterogeneity = 0.589, I2 = 0.0%] risk. For MMP3, no association was found between –1171 5A>6A polymorphism and cancer risk in the overall group [6A versus 5A, OR = 1.00, 95% CI (0.95–1.05), Pheterogeneity = 0.124, I2 = 24.9%] and individual cancer subgroups, but stratified analysis by smoking status showed that this polymorphism had different effects on smokers and non-smokers under recessive genetic model. In summary, our study suggests that MMP1 –1607 2G may be associated with an increased cancer risk for certain types of cancers, MMP3 –1171 5A>6A may not be a major risk factor for cancer, but it may be modified by certain environmental factors. Future studies with larger sample sizes are warranted to further evaluate these associations in more detail.

  H Chu , M Wang , D Gu , D Wu , Z Zhang , J Tang and Z. Zhang
 

Myeloperoxidase (MPO) is an endogenous oxidant enzyme that generates reactive oxygen species and plays an important role in the aetiology of cancer. The MPO –463G>A polymorphism influences MPO transcription and has been implicated in cancer risk. However, results from published studies on the association between the MPO –463G>A polymorphism and risk of cancer are conflicting. To derive a more precise estimation of association between the MPO –463G>A polymorphism and risk of cancer, we performed a meta-analysis based on 43 case–control studies, including a total of 14 171 cancer cases and 17 319 controls. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, individuals with the –463A allele had a 0.93-fold lower cancer risk in a dominant model (OR = 0.93, 95% CI = 0.87–1.00). In the stratified analyses, we observed a similar association in European populations (heterozygote comparison: OR = 0.90, 95% CI = 0.82–0.99) and hospital-based studies (dominant model: OR = 0.88, 95% CI = 0.79–0.99). When stratified by cancer type, however, no significant association was found. The results suggested that the MPO –463A allele does not contribute to the development of cancer. Additional well-designed large studies are required to validate these findings in different populations.

  R Gu , Z Zhang , J. N DeCerbo and G. G. Carmichael
 

We show here that expression of genes from convergent transcription units can be regulated by the formation of double-stranded RNA (dsRNA) in the region of overlapping polyadenylation signals. The model system employed is the mouse polyomavirus. The early and late genes of polyomavirus are transcribed from opposite strands of the circular viral genome. At early times after infection, the early genes are expressed predominantly. Late gene expression increases dramatically upon the onset of DNA replication, when a major defect in polyadenylation of the late primary transcripts generates multigenomic RNAs that are precursors to the mature late mRNAs. Embedded in these late pre-mRNAs are sequences complementary to the early RNAs that act to down-regulate early gene expression via A-to-I editing of dsRNAs. In this system, the defective polyadenylation, and consequently the production of multigenomic late RNAs, depends on the context, and perhaps also, on the A-to-I editing of the poly(A) signal that overlaps the 3'-end of early transcripts.

  A. J Snider , Z Zhang , Y Xie and K. E. Meier
 

Lysophosphatidic acid (LPA), is a lipid mediator that binds to G-protein coupled receptors. Epidermal growth factor (EGF), a polypeptide growth factor, binds to the EGF receptor (EGFR), a receptor tyrosine kinase. Both LPA and EGF induce responses in tumor cells that include proliferation, migration, metastasis, and induction of angiogenesis. LPA has the potential to act as an autocrine/paracrine factor and can transactivate the EGFR. This study explores the role of phospholipase D2 (PLD2) activation in LPA production, as well as cross-talk between EGF and LPA receptors. We demonstrate that EGF and LPA both stimulate production of LPA by OVCAR3 and SKOV3 human ovarian cancer cell lines. PD158780, an EGFR-selective tyrosine kinase inhibitor, blocks LPA production in response to both EGF and LPA in OVCAR3 and SKOV3 cells. Pertussis toxin, an inhibitor of LPA receptor signaling, inhibits LPA production in response to both EGF and LPA. Similar results were observed for the LPA receptor antagonist, Ki16425. Overexpression of PLD2 increases LPA production, while knockdown of PLD2 blocks EGF-induced LPA production. A phospholipase A2 (PLA2) inhibitor also blocks LPA- and EGF-induced LPA production. These results indicate that EGF stimulates LPA production in a manner that requires PLD2, and suggest that cross-talk can occur bidirectionally between EGF and LPA receptors.

  Z Zhang , X Xu , Y Zhang , J Zhou , Z Yu and C. He
 

LINGO-1 is a component of the tripartite receptor complexes, which act as a convergent mediator of the intracellular signaling in response to myelin-associated inhibitors and lead to collapse of growth cone and inhibition of neurite extension. Although the function of LINGO-1 has been intensively studied, its downstream signaling remains elusive. In the present study, a novel interaction between LINGO-1 and a serine-threonine kinase WNK1 was identified by yeast two-hybrid screen. The interaction was further validated by fluorescence resonance energy transfer and co-immunoprecipitation, and this interaction was intensified by Nogo66 treatment. Morphological evidences showed that WNK1 and LINGO-1 were co-localized in cortical neurons. Furthermore, either suppressing WNK1 expression by RNA interference or overexpression of WNK1-(123–510) attenuated Nogo66-induced inhibition of neurite extension and inhibited the activation of RhoA. Moreover, WNK1 was identified to interact with Rho-GDI1, and this interaction was attenuated by Nogo66 treatment, further indicating its regulatory effect on RhoA activation. Taken together, our results suggest that WNK1 is a novel signaling molecule involved in regulation of LINGO-1 mediated inhibition of neurite extension.

  J Wakabayashi , Z Zhang , N Wakabayashi , Y Tamura , M Fukaya , T. W Kensler , M Iijima and H. Sesaki
 

Brain-specific Drp1 knockout mice demonstrate that Drp1-mediated organelle division is important for development, mitochondrial morphogenesis, and apoptosis.

  F. J Vizeacoumar , N van Dyk , F S.Vizeacoumar , V Cheung , J Li , Y Sydorskyy , N Case , Z Li , A Datti , C Nislow , B Raught , Z Zhang , B Frey , K Bloom , C Boone and B. J. Andrews
 

A combination of yeast genetics, synthetic genetic array analysis, and high-throughput screening reveals that sumoylation of Mcm21p promotes disassembly of the mitotic spindle.

 
 
 
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