bluuebunny/crossref_metadata_2025 huggingface dataset:
Maturation of the hippocampal formation and amygdala in Macaca mulatta: A volumetric magnetic resonance imaging study
Authors: Payne Christa , Machado Christopher J. , Bliwise Nancy G. , Bachevalier Jocelyne
Published: September 2009

Malformations of the hippocampal formation and amygdala have been implicated in several neurodevelopmental disorders; yet relatively little is known about their normal structural development. The purpose of this study was to characterize the early developmental trajectories of the hippocampus and amygdala in the rhesus macaques (Macaca mulatta) using noninvasive MRI techniques. T1‐weighted structural scans of 22 infant and juvenile monkeys (11 male, 11 female) were obtained between 1 week and approximately 2 yrs of age. Ten animals (five males, five females) were scanned multiple times and 12 monkeys (six males, six females) were scanned once between 1 and 4 weeks of age. Both structures exhibited significant age‐related changes throughout the first 2 yrs of life that were not explained by overall brain development. The hippocampal formation increased 117.05% in males and 110.86% in females. No sex differences were evident, but the left hemisphere was significantly larger than the right. The amygdala increased 86.49% in males and 72.94% in females with males exhibiting a larger right than left amygdala. For both structures, the most substantial volumetric increases were seen within the first month, but the hippocampal formation appeared to develop more slowly than the amygdala with the rate of hippocampal maturation stabilizing around 11 months and that of amygdala maturation stabilizing around 8 months. Differences in volumetric developmental trajectories of the hippocampal formation and amygdala largely mirror differences in the timing of the functional development of these structures. The current results emphasize the importance of including early postnatal ages when assessing developmental trajectories of neuroanatomical structures and reinforces the utility of nonhuman primates in the assessment of normal developmental patterns. © 2009 Wiley‐Liss, Inc.
Distinct modes of modulation of GABAergic transmission by Group I metabotropic glutamate receptors in rat entorhinal cortex
Authors: Deng Pan‐Yue , Xiao Zhaoyang , Lei Saobo
Published: September 2009

Activation of metabotropic glutamate receptors (mGluRs) modulates synaptic transmission, whereas the roles of mGluRs in GABAergic transmission in the entorhinal cortex (EC) are elusive. Here, we examined the effects of mGluRs on GABAergic transmission onto the principal neurons in the superficial layers of the EC. Bath application of DHPG, a selective Group I mGluR agonist, increased the frequency and amplitude of spontaneous IPSCs (sIPSCs) whereas application of DCG‐IV, an agonist for Group II mGluRs or L‐AP4, an agonist for Group III mGluRs failed to change significantly sIPSC frequency and amplitude. Bath application of DHPG failed to change significantly the frequency and amplitude of miniature IPSCs (mIPSCs) recorded in the presence of tetradotoxin but significantly reduced the amplitude of IPSCs evoked by extracellular field stimulation or in synaptically connected interneuron‐pyramidal neuron pairs in layer III of the EC. DHPG increased the frequency but reduced the amplitude of APs recorded from entorhinal interneurons. Bath application of DHPG generated membrane depolarization and increased the input resistance of GABAergic interneurons. DHPG‐mediated depolarization of GABAergic interneurons was mediated by inhibition of background K+ channels which are insensitive to extracellular Cs+, TEA, 4‐AP, and Ba2+. DHPG‐induced facilitation of sIPSCs was mediated by mGluR5 and required the function of Gαq but was independent of phospholipase C activity. Elevation of synaptic glutamate concentration by bath application of glutamate transporter inhibitors significantly increased sIPSC frequency and amplitude demonstrating a physiological role of mGluRs in GABAergic transmission. Our results provide a cellular and molecular mechanism to explain the physiological and pathological roles of mGluRs in the EC. © 2009 Wiley‐Liss, Inc.
Exchange protein activated by cyclic AMP 2 (Epac2) plays a specific and time‐limited role in memory retrieval
Authors: Ostroveanu Anghelus , van der Zee Eddy A. , Eisel Ulrich L.M. , Schmidt Martina , Nijholt Ingrid M.
Published: September 2009

Knowledge on the molecular mechanisms involved in memory retrieval is limited due to the lack of tools to study this stage of the memory process. Here we report that exchange proteins activated by cAMP (Epac) play a surprisingly specific role in memory retrieval. Intrahippocampal injection of the Epac activator 8‐pCPT‐2′O‐Me‐cAMP was shown to improve fear memory retrieval in contextual fear conditioning whereas acquisition and consolidation were not affected. The retrieval enhancing effect of the Epac activator was even more prominent in the passive avoidance paradigm. Down‐regulation of Epac2 expression in the hippocampal CA1 area impaired fear memory retrieval when the memory test was performed 72 h after training, but not when tested after 17 days. Our data thus identify an important time‐limited role for hippocampal Epac2 signaling in cognition and opens new avenues to investigate the molecular mechanisms underlying memory retrieval. © 2009 Wiley‐Liss, Inc.
Expression of the snoRNA host gene gas5 in the hippocampus is upregulated by age and psychogenic stress and correlates with reduced novelty‐induced behavior in C57BL/6 mice
Authors: Meier Ingo , Fellini Laetitia , Jakovcevski Mira , Schachner Melitta , Morellini Fabio
Published: September 2009

The growth arrest specific 5 (gas5) is a noncoding protein gene that hosts small nucleolar RNAs. Based on the observation that gas5 RNA level in the brain is highest in the hippocampus and remarkably enhanced in aged mice, we tested the hypothesis that gas5 is involved in functions controlled by the hippocampus and known to be affected by age, such as spatial learning and novelty‐induced behaviors. We show that aged (22‐month‐old) C57BL/6 male mice have spatial‐learning impairments, reduced novelty‐induced exploration, and enhanced gas5 RNA levels in the hippocampus compared to young (3‐month‐old) mice. At both ages, levels of gas5 RNA in the hippocampus negatively correlated with novelty‐induced exploration in the open field and elevated‐plus maze tests. No correlations were found between gas5 RNA levels in the hippocampus and performance in the water maze test. The expression of gas5 RNA in the rest of the brain did not correlate with any behavioral parameter analyzed. Because variations in novelty‐induced behaviors could be caused by stressfull experiences, we analyzed whether gas5 RNA levels in the hippocampus are regulated by acute stressors. We found that gas5 RNA levels in the hippocampus were upregulated by 50% 24 h after a psychogenic stressor (60‐min olfactory contact with a rat) but were unchanged after exposure to an unfamiliar environment or after acquisition of new spatial information in a one‐trial learning task. The present results suggest that strong psychogenic stressors upregulate gas5 RNA in the hippocampus, which in turn affects novelty‐induced responses controlled by this region. We hypothesize that long‐life exposure to stressors causes an age‐dependent increase in hippocampal gas5 RNA levels, which could be responsible for age‐related reduced novelty‐induced behaviors, thus suggesting a new mechanism by which ageing and stress affect hippocampal function. © 2009 Wiley‐Liss, Inc.
Functional emergence of the hippocampus in context fear learning in infant rats
Authors: Raineki Charlis , Holman Parker J. , Debiec Jacek , Bugg Melissa , Beasley Allyson , Sullivan Regina M.
Published: September 2009

The hippocampus is a part of the limbic system and is important for the formation of associative memories, such as acquiring information about the context (e.g., the place where an experience occurred) during emotional learning (e.g., fear conditioning). Here, we assess whether the hippocampus is responsible for pups' newly emerging context learning. In all experiments, postnatal day (PN) 21 and PN24 rat pups received 10 pairings of odor‐0.5 mA shock or control unpaired odor‐shock, odor only, or shock only. Some pups were used for context, cue or odor avoidance tests, while the remaining pups were used for c‐Fos immunohistochemistry to assess hippocampal activity during acquisition. Our results show that cue and odor avoidance learning were similar at both ages, while contextual fear learning and learning‐associated hippocampal (CA1, CA3, and dentate gyrus) activity (c‐Fos) only occurred in PN24 paired pups. To assess a causal relationship between the hippocampus and context conditioning, we infused muscimol into the hippocampus, which blocked acquisition of context fear learning in the PN24 pups. Muscimol or vehicle infusions did not affect cue learning or aversion to the odor at PN21 or PN24. The results suggest that the newly emerging contextual learning exhibited by PN24 pups is supported by the hippocampus. © 2009 Wiley‐Liss, Inc.
Two New Kaempferol Glycosides from Androsace umbellata
Authors: Lei Jun , Xiao Yun‐Chuan , Huang Jing , Tang Min , Deng Peng‐Chi
Published: September 2009

Two new kaempferol glycosides, 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐(α‐L‐rhamnopyranosyloxy)‐4H‐chromen‐3‐yl 2‐O‐acetyl‐3‐O‐β‐D‐glucopyranosyl‐α‐L‐rhamnopyranoside (1) and 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐(α‐L‐rhamnopyranosyloxy)‐4H‐chromen‐3‐yl β‐D‐glucopyranosyl‐(1→2)‐6‐O‐[(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐β‐D‐glucopyranosyl‐(1→2)‐β‐D‐glucopyranoside (2), along with ten known compounds, were isolated from the 95% EtOH extract of the whole plant of Androsace umbellata. The structures of the new glycosides were determined on the basis of detailed spectroscopic analyses, including 1D‐ and 2D‐NMR, MS, and chemical methods.
Unexpected Ring Expansion of the (3aS,6aR)‐γ‐Thiolactone Moiety during the Introduction of the (+)‐Biotin Side Chain
Authors: Huang Jian , Xiong Fei , Wang Zhong‐Hua , Chen Fen‐Er
Published: September 2009

The reaction of vinylmagnesium bromide with the (3aS,6aR)‐γ‐thiolactone 2 in THF afforded, after unexpected ring expansion of the γ‐thiolactone moiety, the seven‐membered‐ring ketone 5 in excellent yield, instead of the expected tertiary alcohol 3.
Sesquiterpenes from the Marine Red Alga Laurencia saitoi
Authors: Su Hua , Yuan Zhao‐Hui , Li Jing , Guo Shu‐Ju , Deng Li‐Ping , Han Li‐Jun , Zhu Xiao‐Bin , Shi Da‐Yong
Published: September 2009

Together with five known sesquiterpenes, EtOH extraction of Laurencia saitoi yielded four new compounds, including three sesquiterpenes and one norsesquiterpene derivative. Their structures and relative configurations were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR (1H,1H‐COSY, HMQC, HMBC, and NOESY), as well as low‐ and high‐resolution mass‐spectrometric analyses.
Five New Triterpenoids from the Roots of Kadsura coccinea
Authors: Wang Nan , Li Zhan‐Lin , Li Dan‐Yi , Pei Yue‐Hu , Hua Hui‐Ming
Published: September 2009

A phytochemical investigation of an EtOH extract of the roots of Kadsura coccinea (Lem.) A. C. Sm. furnished five new lanostane‐type triterpenoids, coccinone A (1), coccinone B (2), coccinone C (3), coccinone D (4), and coccinilactone B (5). Their structures were determined based on spectroscopic analyses, including 2D‐NMR experiments and HR‐MS techniques.
Three New ent‐Labdane Diterpenoids from the Wood of Excoecaria agallochaLinn.
Authors: Gowri Ponnapalli Mangala , Bhattar Sri Vedavyasa Srirangaraja Radhakrishnan , Reddy Poreddy Guruva , Rakesh Yerraballi , Basha Shaik Jeelani , Sarma Akella Venkata Subrahmanya , Rao Janaswamy Madhusudana
Published: September 2009

An extensive study of metabolites present in Excoecaria agallocha Linn. led to the isolation of three new ent‐labdane‐type diterpenoids, named agallochaexcoerins A–C (1–3), besides three known compounds. The skeleton present in compound 1 is rather unusual, containing of a seven‐membered lactone. The structures were elucidated on the basis of spectroscopic studies and comparison with known related compounds. The isolated compounds 1–6 were not active against Raw 264.7 (macrophage‐like), K 562 (leukemia), and COLO 205 (colon) human carcinoma cell lines.
Four New Eudesmane Sesquiterpenoid Lactones from Chloranthus serratus
Authors: Teng Fei , Zhong Hui‐Min , Chen Chang‐Xiang , Liu Hai‐Yang
Published: September 2009

Four new eudesmane sesquiterpenoids endowed with an α,β‐unsaturated γ‐lactone five‐membered ring, serralactones A–D (1–4, resp.), along with seven known sesquiterpenoids, were isolated from the whole plant Chloranthus serratus. Their structures and relative configurations were established on the basis of extensive spectroscopic analyses.
Nitrogen‐Rich Compounds of the Lanthanoids: The 5,5′‐Azobis[1H‐tetrazol‐1‐ides] of some Yttric Earths (Tb, Dy, Ho, Er, Tm, Yb, and Lu)
Authors: Steinhauser Georg , Giester Gerald , Wagner Christoph , Leopold Nicolae , Sterba Johannes H. , Lendl Bernhard , Bichler Max
Published: September 2009

A set of N‐rich salts, 3–9, of the heavy lanthanoids (terbium, 3; dysprosium, 4; holmium 5; erbium, 6; thulium, 7; ytterbium, 8; lutetium, 9) based on the energetic 5,5′‐azobis[1H‐tetrazole] (H2ZT) was synthesized and characterized by elemental analysis, vibrational (IR and Raman) spectroscopy, and X‐ray structure determination. The synthesis of the lanthanoid salts 3–9 was performed by crystallization from concentrated aqueous solutions of disodium 5,5′‐azobis[1H‐tetrazol‐1‐ide] dihydrate (Na2ZT⋅2 H2O; 1) and the respective Ln(NO3)3⋅5 H2O and yielded large rhombic crystals of the type [Ln(H2O)8]2(ZT)3⋅6 H2O in ca. 70% of the theoretical yield. The compounds 3–9 are isostructural (triclinic space group P$\bar 1$) to the previously published yttrium salt 2; they show, however, a clear lanthanoid contraction of several crystallographic parameters, e.g., the cell volume or the LnO bond lengths of the Ln3+ ions and the coordinating H2O molecules. The lanthanoid contraction influences the strengths of the H‐bonds, which can be observed as a red shift by 4 cm−1 in the characteristic IR band, in particular from 3595 cm−1 (3) to 3599 cm−1 (9). In good agreement with previous works, 2–9 are purely salt‐like compounds without a coordinative bond between the tetrazolide anion and the Ln3+ cation.
Upregulated claudin‐1 expression confers resistance to cell death of nasopharyngeal carcinoma cells
Authors: Lee Jeng‐Woei , Hsiao Wei‐Ting , Chen Hsia‐Yun , Hsu Lee‐Ping , Chen Peir‐Rong , Lin Ming‐Der , Chiu Shu‐Jun , Shih Wen‐Ling , Hsu Yih‐Chih
Published: September 2009

Accumulating evidence reveals that aberrant expression of claudins manifests in various tumors; however, their biological functions are poorly understood. Here, we report on the elevated expression of claudin‐1 in nasopharyngeal carcinoma (NPC) cell lines under serum deprivation or fluorouracil (5‐FU) treatment. Interestingly, an increase in expression of claudin‐1 considerably reduced apoptosis rather than enhancing cell proliferation. However, claudin‐1 expression and activity were unaffected by external stimuli or Akt and NF‐κB activation. Notably, predominant cytoplasmic and nuclear localization of claudin‐1 in NPC cells reflected the aforementioned feature. On the other hand, loss of epithelial morphology and E‐cadherin expression was associated with serum withdrawal in NPC cells. Interestingly, restoration of E‐cadherin inhibited the protein elevation and antiapoptotic activity of claudin‐1. In conclusion, our data demonstrate the regulation and novel biological function of claudin‐1 and indicate the important role of claudin‐1 in NPC tumorigenesis.
Hospicells derived from ovarian cancer stroma inhibit T‐cell immune responses
Authors: Martinet Ludovic , Poupot Rémy , Mirshahi Pejman , Rafii Arash , Fournié Jean‐Jacques , Mirshahi Massoud , Poupot Mary
Published: September 2009

With metastatic disease at diagnosis for 70% of patients, ovarian cancer represents the most lethal gynecological malignancy. Ovarian carcinomas are aggressive malignancies that can evade immune surveillance and frequently develop into metastases. The tumor microenvironment is decisive for preventing immune attack but, in the case of ovarian carcinoma, the mechanisms are unclear. We recently isolated a novel type of stromal cell from the ascitis of patients with ovarian carcinoma that interacts with epithelial ovarian cancers conferring them chemoresistance. These cells, called Hospicells, have the cell surface markers CD9, CD10, CD29, CD146 and CD166. Here, we investigated whether Hospicells also have immunomodulatory functions that might interfere with immunity to cancer. We report that Hospicells inhibit the proliferation of human CD4+, CD8+ and Vγ9Vδ2 T cells in vitro and the production of cytokines by these immune cells. The immunosuppression of CD4+ T cells is independent of direct contact with the Hospicells and is mainly due to nitric oxide produced by the inducible nitric oxide synthase and to products of the tryptophan degradation by indoleamine 2,3‐dioxygenase. We proposed that Hospicells in the microenvironment of the tumor mediate immunosuppression of T cells and thus allow ovarian cancers to evade immune surveillance. Targeting of Hospicells could be an alternative to strong chemotherapy through the recovery of immune responses against tumor cells.
The effects of gefitinib in tamoxifen‐resistant and hormone‐insensitive breast cancer: A phase II study
Authors: Gutteridge Eleanor , Agrawal Amit , Nicholson Robert , Cheung Kwok Leung , Robertson John , Gee Julia
Published: September 2009

Estrogen receptor (ER)‐positive acquired tamoxifen‐resistant (TAM‐R) MCF‐7 breast cancer cell lines exhibit epidermal growth factor receptor (EGFR) expression/signaling and are growth‐inhibited by gefitinib (IRESSA). We examined the effect of gefitinib on ER‐positive TAM‐R and ER‐negative hormone‐insensitive breast cancer in a Phase II study. Fifty‐four patients with breast cancer [ER‐positive/acquired TAM‐R (n = 28); ER‐negative (n = 26)] received oral gefitinib 500 mg/day. Tumor biopsies were taken pre‐ (n = 28) and 8 weeks post‐treatment (n = 14 matched samples). Gefitinib was well tolerated and the clinical benefit rate (objective response or stable disease >24 weeks) was 33.3% overall (n = 18/54), and 53.6 and 11.5% in ER‐positive/TAM‐R and ER‐negative patients, respectively. Pretreatment ER and progesterone receptor‐positivity were associated with response (p < 0.001 and 0.016, respectively) and longer progression‐free survival (PFS; p= 0.001 and 0.013, respectively). All patients expressed EGFR, but high pretreatment levels predicted poorer outcome (p = 0.005) and shorter PFS (p = 0.012) with gefitinib. In patients with clinical benefit, reduced Ki67 staining during treatment (p = 0.024) was commonly observed, and those with >10% decline in EGFR phosphorylation demonstrated parallel decreases in ERK1/2 MAPK phosphorylation. Acquired tamoxifen resistance appears in part mediated through EGFR signaling and can be blocked with gefitinib.
Hospicells (ascites‐derived stromal cells) promote tumorigenicity and angiogenesis
Authors: Pasquet Marlene , Golzio Muriel , Mery Eliane , Rafii Arash , Benabbou Nadia , Mirshahi Pezhman , Hennebelle Isabelle , Bourin Philippe , Allal Ben , Teissie Justin , Mirshahi Massoud , Couderc Bettina
Published: September 2009

The microenvironment is known to play a dominant role in cancer progression. Cells closely associated with tumoral cells, named hospicells, have been recently isolated from the ascites of ovarian cancer patients. Whilst these cells present no specific markers from known cell lineages, they do share some homology with bone marrow‐derived or adipose tissue‐derived human mesenchymal stem cells (CD9, CD10, CD29, CD146, CD166, HLA‐1). We studied the role of hospicells in ovarian carcinoma progression. In vitro, these cells had no effect on the growth of human ovarian carcinoma cell lines OVCAR‐3, SKOV‐1 and IGROV‐1. In vivo, their co‐injection with adenocarcinoma cells enhanced tumor growth whatever the tumor model used (subcutaneous and intraperitoneally established xenografts in athymic mice). In addition, their injection increased the development of ascites in tumor‐bearing mice. Fluorescent macroscopy revealed an association between hospicells and ovarian adenocarcinoma cells within the tumor mass. Tumors obtained by coinjection of hospicells and human ovarian adenocarcinoma cells presented an increased microvascularization indicating that the hospicells could promote tumorigenicity of ovarian tumor cells in vivovia their action on angiogenesis. This effect on angiogenesis could be attributed to the increased HIF1α and VEGF expression associated with the presence of the hospicells. Collectively, these data indicate a role for these ascite‐derived stromal cells in promoting tumor growth by increasing angiogenesis.
Therapy for minimal residual tumor disease: β‐Galactosylceramide inhibits the growth of recurrent HPV16‐associated neoplasms after surgery and chemotherapy
Authors: Šímová Jana , Indrová Marie , Bieblová Jana , Mikyšková Romana , Bubeník Jan , Reiniš Milan
Published: September 2009

Natural killer T (NKT) cells are potent modulators of antitumor immunity. Their protective effects can be achieved upon their activation by glycolipid ligands presented in the context of the CD1d molecule. These CD1d‐binding glycolipid antigens have been described as potent therapeutic agents against tumors, infections, as well as autoimmune diseases. Immunoregulatory and therapeutic effects of glycolipid ligands depend on their structure and modes of administration. Therefore, more studies are needed for optimization of the particular therapeutic settings. This study was focused on the tumor‐inhibitory effects of 12 carbon acyl chain β‐galactosyl ceramide (C12 β‐D‐Galactosyl Ceramide; β‐GalCer(C12)) on the growth of human papillomavirus type 16 (HPV16)‐associated neoplasms transplanted in syngeneic mice. Treatment of tumor‐bearing mice with β‐GalCer(C12) 3–14 days after tumor cell transplantation significantly inhibited the growth of the major histocompatability complex (MHC) Class I‐positive (TC‐1), as well as MHC Class I‐deficient (TC‐1/A9) HPV16‐asssociated tumors. Moreover, administration of β‐GalCer(C12) after surgical removal of TC‐1 tumors inhibited the growth of tumor recurrences. Similar results were obtained in the treatment of tumors after chemotherapy. β‐GalCer(C12) treatment turned out to be also synergistic with immunotherapy based on administration of IL‐12‐producing cellular vaccines. These results suggest that β‐GalCer(C12), whose antitumor effects have so far not been studied in detail, can be effective for the treatment of minimal residual tumor disease as well as an adjuvant for cancer immunotherapy.
Polymorphisms in genes of the steroid receptor superfamily modify postmenopausal breast cancer risk associated with menopausal hormone therapy
Authors:   The MARIE‐GENICA Consortium on Genetic Susceptibility for Menopausal Hormone Therapy Related Breast Cancer Risk
Published: September 2009

Menopausal hormone therapy (HT) is associated with increased breast cancer risk among postmenopausal women. Nuclear receptors are involved in steroid hormone‐ and xenobiotic‐mediated signal transduction playing a crucial role in regulating gene expression. Therefore, variations within these genes may influence HT‐associated breast cancer risk. We investigated 3,149 postmenopausal breast cancer patients and 5,489 controls from 2 German population‐based case‐control studies. Thirty‐three polymorphisms selected on the basis of known or putative functional relevance located inESR1, ESR2, PGR, PXRandARwere genotyped. Conditional logistic regression was used to assess multiplicative statistical interaction between polymorphisms and duration of estrogen–progestagen therapy and of estrogen monotherapy with regard to breast cancer risk assuming log‐additive and codominant modes of inheritance. We observed an increased risk for women carrying shortAR_(CAG) alleles of <22 repeats associated with combined estrogen–progestagen therapy compared with those with long alleles (≥22 repeats) (pinteraction= 0.03). Additionally, risk associated with combination therapy use was significantly modified by 2PXRpolymorphisms with reduction of risk effects in carriers of the minorPXR_rs6785049_G andPXR_rs1054191_A alleles (pinteraction= 0.04 and 0.05, respectively). Variants in bothESR1andESR2modified risk associated with estrogen monotherapy use. Higher risk were observed in homozygotes for the majorESR1_rs910416_T allele (pinteraction< 0.01) and in homozygotes for the minorESR2_rs1271572_T, majorESR2_rs4986938_G and minorESR2_rs928554_G alleles (pinteraction= 0.02, 0.05, 0.02, respectively). Risk effect modification byESR1_rs910416 andAR_(CAG)n polymorphisms remained significant after correction for multiple testing. We conclude that genetic variants in nuclear receptor genes may modify HT‐associated postmenopausal breast cancer risk.
Mismatch repair system decreases cell survival by stabilizing the tetraploid G1 arrest in response to SN‐38
Authors: Bhonde Mandar Ramesh , Hanski Marie‐Luise , Stehr Jenny , Jebautzke Britta , Peiró‐Jordán Roser , Fechner Henry , Yokoyama Kazunari Kazushige , Lin Weei‐Chin , Zeitz Martin , Hanski Christoph
Published: September 2009

The role of the mismatch repair (MMR) system in correcting base–base mismatches is well established; its involvement in the response to DNA double strand breaks, however, is less clear. We investigated the influence of the essential component of MMR, the hMLH1 protein, on the cellular response to DNA‐double strand breaks induced by treatment with SN‐38, the active metabolite of topoisomerase I inhibitor irinotecan, in a strictly isogenic cell system (p53wt, hMLH1+/p53wt, hMLH1−). By using hMLH1 expressing clones or cells transduced with the hMLH1‐expressing adenovirus as well as siRNA technology, we show that in response to SN‐38‐induced DNA damage the MMR proficient (MMR+) cells make: (i) a stronger G2/M arrest, (ii) a subsequent longer tetraploid G1 arrest, (iii) a stronger activation of Chk1 and Chk2 kinases than the MMR deficient (MMR−) counterparts. Both Cdk2 and Cdk4 kinases contribute to the basal tetraploid G1 arrest in MMR+ and MMR− cells. Although the Chk1 kinase is involved in the G2/M arrest, neither Chk1 nor Chk2 are involved in the enhancement of the tetraploid G1 arrest. The long‐lasting tetraploid G1 arrest of MMR+ cells is associated with their lower clonogenic survival after SN‐38 treatment, the abrogation of the tetraploid G1 arrest resulted in their better clonogenic survival. These data show that the stabilization of the tetraploid G1 arrest in response to double strand breaks is a novel function of the MMR system that contributes to the lesser survival of MMR+ cells.
The nuclear architectural protein HMGA1a triggers receptor‐mediated endocytosis
Authors: Wu Wuwei , Wan Wei , Li Alexander D.Q.
Published: September 2009

High mobility group proteins A (HMGA), nuclear architectural factors, locate in the cell nuclei and mostly execute gene‐regulation function. However, our results reveal that a HMGA member (HMGA1a) has a unique plasma membrane receptor; this receptor specifically binds to HMGA‐decorated species, effectively mediates endocytosis, and internalizes extracellular HMGA‐functionalized cargoes. Indeed, dyes or nanoparticles labeled with HMGA1a protein readily enter Hela cells. Using a stratagem chemical cross‐linker, we covalently bonded the HMGA receptor to the HMGA1a‐GFP fusion protein, thus capturing the plasma membrane receptor. Subsequent Western blots and SDS–PAGE gel revealed that the HMGA receptor is a 26‐kDa protein. Confocal live‐cell microscopic imaging was used to monitor the whole endocytic process, in which the internalized HMGA1a‐decorated species are transported by motor proteins on microtubules and eventually arrive at the late endosomes/lysosomes. Cell viability assays also suggested that extracellular HMGA1a protein directly influences the survival ability of Hela cells in a dose‐dependent manner, implying versatility of HMGA1a protein and its potent role to suppress cancer cell survivability and to regulate growth. J. Cell. Biochem. 108: 791–801, 2009. © 2009 Wiley‐Liss, Inc.
Attenuating Smac mimetic compound 3‐induced NF‐κB activation by luteolin leads to synergistic cytotoxicity in cancer cells
Authors: Bai Lang , Chen Wenjie , Wang Xia , Ju Wei , Xu Shanling , Lin Yong
Published: September 2009

Smac mimetics are potential anticancer therapeutics selectively killing cancer cells through autocrine tumor necrosis factor (TNF)‐mediated apoptosis pathway. Our recent study reveal that the Smac mimetic compound 3 (SMC3)‐activated NF‐κB protects cancer cells against apoptosis, thus blunting SMC3's anticancer activity. Based on our previous observations that the nutrient flavonoid luteolin potently blocks TNF‐induced NF‐κB activation in cancer cells, we investigated if the combination of SMC3 and luteolin would achieve a synergistic anticancer activity. The results show that luteolin had no effect on autocrine TNF but it effectively blocked SMC3‐induced nuclear factor kappa B (NF‐κB) activation and expression of anti‐apoptotic NF‐κB targets. When SMC3 and luteolin were combined in treating cancer cells derived from lung and liver tumors, the activation of TNF‐dependent apoptosis was markedly sensitized and a synergistic cytotoxic effect was achieved. In addition, the SMC3 and luteolin co‐treatment had marginal effect on immortalized normal human bronchial epithelial cells. The results suggest that combination of SMC3 and luteolin is an effective approach for improving the anticancer value of SMC3, which has implications in cancer prevention and therapy. J. Cell. Biochem. 108: 1125–1131, 2009. © 2009 Wiley‐Liss, Inc.
Impaired cell cycle regulation of the osteoblast‐related heterodimeric transcription factor Runx2‐Cbfβ in osteosarcoma cells
Authors: San Martin Inga A. , Varela Nelson , Gaete Marcia , Villegas Karina , Osorio Mariana , Tapia Julio C. , Antonelli Marcelo , Mancilla Edna E. , Pereira Barry P. , Nathan Saminathan S. , Lian Jane B. , Stein Janet L. , Stein Gary S. , van Wijnen Andre J. , Galindo Mario
Published: September 2009

Bone formation and osteoblast differentiation require the functional expression of the Runx2/Cbfβ heterodimeric transcription factor complex. Runx2 is also a suppressor of proliferation in osteoblasts by attenuating cell cycle progression in G1. Runx2 levels are modulated during the cell cycle, which are maximal in G1 and minimal beyond the G1/S phase transition (S, G2, and M phases). It is not known whether Cbfβ gene expression is cell cycle controlled in preosteoblasts nor how Runx2 or Cbfβ are regulated during the cell cycle in bone cancer cells. We investigated Runx2 and Cbfβ gene expression during cell cycle progression in MC3T3‐E1 osteoblasts, as well as ROS17/2.8 and SaOS‐2 osteosarcoma cells. Runx2 protein levels are reduced as expected in MC3T3‐E1 cells arrested in late G1 (by mimosine) or M phase (by nocodazole), but not in cell cycle arrested osteosarcoma cells. Cbfβ protein levels are cell cycle independent in both osteoblasts and osteosarcoma cells. In synchronized MC3T3‐E1 osteoblasts progressing from late G1 or mitosis, Runx2 levels but not Cbfβ levels are cell cycle regulated. However, both factors are constitutively elevated throughout the cell cycle in osteosarcoma cells. Proteasome inhibition by MG132 stabilizes Runx2 protein levels in late G1 and S in MC3T3‐E1 cells, but not in ROS17/2.8 and SaOS‐2 osteosarcoma cells. Thus, proteasomal degradation of Runx2 is deregulated in osteosarcoma cells. We propose that cell cycle control of Runx2 gene expression is impaired in osteosarcomas and that this deregulation may contribute to the pathogenesis of osteosarcoma. J. Cell. Physiol. 221: 560–571, 2009. © 2009 Wiley‐Liss, Inc.
p38SJ, a novel DINGG protein protects neuronal cells from alcohol induced injury and death
Authors: Amini Shohreh , Merabova Nana , Khalili Kamel , Darbinian Nune
Published: September 2009

Ethanol induces neuronal cell injury and death by dysregulating several signaling events that are controlled, in part, by activation of MAPK/ERK1/2 and/or inactivation of its corresponding phosphatase, PP1. Recently, we have purified a novel protein of 38 kDa in size, p38SJ, from a callus culture ofHypericum perforatum, which belongs to an emerging DINGG family of proteins with phosphate binding activity. Here, we show that treatment of neuronal cells with p38SJ protects cells against injury induced by exposure to ethanol. Furthermore, pre‐treatment of neuronal cells with p38SJ diminishes the level of the pro‐apoptotic protein Bax and some events associated with apoptosis such as caspase 3 cleavage. In addition, by inducing stress, alcohol can elevate production of reactive oxygen species (ROS) that leads to a decrease in the activity of superoxide dismutase (SOD). Our results showed that p38SJ restores the activity of SOD in the ethanol treated neuronal cells. These observations provide a novel biological tool for developing new approaches for preventing neuronal cell death induced by ethanol and possibly treatment of neurological disorders associated with alcohol abuse. J. Cell. Physiol. 221: 499–504, 2009. © 2009 Wiley‐Liss, Inc.
LG4–5 domains of laminin‐211 binds α‐Dystroglycan to allow myotube attachment and prevent anoikis
Authors: Munoz Jesus , Zhou Yanwen , Jarrett Harry W.
Published: September 2009

Poly(2‐hydroxyethyl methacrylate) (PolyHEMA) prevents cell attachment was used here to study anoikis, the process where cells die when unattached or attached to an inappropriate matrix, in mouse C2C12 myotubes. A method was developed to efficiently embed proteins into PolyHEMA and the effect on cultured myotubes was determined. Myotubes grown on PolyHEMA‐coated plates fail to attach to the surface and remain as rounded, suspended cells, undergo dramatic increases in apoptosis and necrosis, and the number of viable cells decreases. Incorporation of merosin (laminin‐211) or the short laminin globular (LG4–5) modules of the laminin‐α2 chain C‐terminus (called 2E3) that binds α‐dystroglycan diminishes both apoptosis and necrosis and increases viability while bovine serum albumin had a much lesser effect, showing the specificity of this effect for these matrix proteins. One sarcolemma receptor for laminin‐binding is α‐dystroglycan. An antibody which binds α‐dystroglycan but which does not block laminin‐binding (VIA4) had little effect on apoptosis or viability on merosin or 2E3 embedded plates while another antibody (IIH6) which specifically blocks binding dramatically decreased viability and increased apoptosis. When merosin or 2E3 are added to culture media rather than embedded on plates these can also increase viability and decrease apoptosis even though the cells remain in suspension, though the effect is not as great as found for the embedded proteins where the cells attach. Thus, we conclude that the binding of a small LG4–5 modules of laminin‐211 to α‐dystroglycan is important in preventing anoikis and that attachment plus binding is necessary for maximal cell survival. J. Cell. Physiol. 222:111–119, 2010. © 2009 Wiley‐Liss, Inc.
Thyroid follicular neoplasms: Can sonography distinguish between adenomas and carcinomas?
Authors: Seo Hyung Suk , Lee Dong Hoon , Park Sung Hye , Min Hye Sook , Na Dong Gyu
Published: September 2009

Purpose

The purpose of this study was to determine whether sonography (US) can usefully differentiate thyroid follicular adenoma (FA) and follicular carcinoma (FC).

Methods

This retrospective study included 60 pathologically proven FAs and 66 FCs in 123 consecutive patients (17 males and 106 females) with a mean age of 47 ± 13 years, (17–73 years) who underwent thyroid surgery. We analyzed US features of each nodule, including maximum diameter, echogenicity, composition, presence of calcification, margins, and presence of halo. The frequencies of each US feature were compared by using the χ2 test or Fisher's exact test between FAs and FCs. The relative risk of malignancy was evaluated by logistic regression analysis.

Results

Isohypoechoic echogenicity, predominantly solid or mixed echotexture, and presence of microcalcifications or rim calcifications were associated with FC (p < 0.05). Logistic regression analysis demonstrated that predominantly solid or mixed echotexture and microcalcifications or rim calcifications were associated with significant increases in relative risk for FC (odds ratio 8.1 and odds ratio 13.5, respectively, p < 0.01).

Conclusions

The US features of isohypoechoic echogenicity, predominantly solid or mixed echotexture, and microcalcifications or rim calcifications are more common in FC than in FA. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Computational approaches to identifying and characterizing protein binding sites for ligand design
Authors: Henrich Stefan , Salo‐Ahen Outi M. H. , Huang Bingding , Rippmann Friedrich F. , Cruciani Gabriele , Wade Rebecca C.
Published: September 2009

Given the three‐dimensional structure of a protein, how can one find the sites where other molecules might bind to it? Do these sites have the properties necessary for high affinity binding? Is this protein a suitable target for drug design? Here, we discuss recent developments in computational methods to address these and related questions. Geometric methods to identify pockets on protein surfaces have been developed over many years but, with new algorithms, their performance is still improving. Simulation methods show promise in accounting for protein conformational variability to identify transient pockets but lack the ease of use of many of the (rigid) shape‐based tools. Sequence and structure comparison approaches are benefiting from the constantly increasing size of sequence and structure databases. Energetic methods can aid identification and characterization of binding pockets, and have undergone recent improvements in the treatment of solvation and hydrophobicity. The “druggability” of a binding site is still difficult to predict with an automated procedure. The methodologies available for this purpose range from simple shape and hydrophobicity scores to computationally demanding free energy simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Cuprizone induces similar demyelination in male and female C57BL/6 mice and results in disruption of the estrous cycle
Authors: Taylor Lorelei C. , Gilmore Wendy , Ting Jenny P.‐Y. , Matsushima Glenn K.
Published: September 2009

Multiple sclerosis is a demyelinating neurological disease that is influenced by gender, primarily reflected in greater susceptibility to disease development in women than in men. Cuprizone intoxication, an animal model that is used to study demyelination and remyelination, has been extensively characterized in male C57BL/6 mice. Here, we have undertaken a comprehensive characterization of the morphological and cellular processes that occur in female C57BL/6J mice during cuprizone‐induced demyelination and subsequent remyelination and compared them with age‐matched male mice. We find that the pattern of demyelination and remyelination is similar between genders and that there is little or no difference in the loss or repopulation of mature oligodendrocytes or accumulation of reactive glia. Furthermore, examination of αERKO and βERKO mice suggests that estrogen receptors do not affect the outcome for demyelination or remyelination. Interestingly, we found that cuprizone treatment disrupts estrous cyclicity in female mice, possibly interfering with potential hormone influences on demyelination and remyelination. Therefore, cuprizone‐induced demyelination in C57BL/6J mice may have limitations as a model for the study of sex differences. © 2009 Wiley‐Liss, Inc.
Altered AMPA receptor expression with treadmill exercise in the 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine‐lesioned mouse model of basal ganglia injury
Authors: VanLeeuwen Jon‐Eric , Petzinger Giselle M. , Walsh John P. , Akopian Garnik K. , Vuckovic Marta , Jakowec Michael W.
Published: September 2009

Dopamine depletion leads to impaired motor performance and increased glutamatergic‐mediated hyperexcitability of medium spiny neurons in the basal ganglia. Intensive treadmill exercise improves motor performance in both saline treatment and the 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) mouse model of Parkinson's disease. In the present study, we investigated the effect of high‐intensity treadmill exercise on changes in alpha‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor (AMPAR) subunit expression, because these receptor channels confer the majority of fast excitatory neurotransmission in the brain, and their subunit composition provides a key mechanism for regulating synaptic strength and synaptic neuroplasticity and is important in modulating glutamatergic neurotransmission. Within the dorsolateral striatum of MPTP mice, treadmill exercise increased GluR2 subunit expression, with no significant effect on GluR1. Furthermore, neurophysiological studies demonstrated a reduction in the size of excitatory postsynaptic currents (EPSCs) in striatal medium spiny neurons (as determined by the input‐output relationship), reduced amplitude of spontaneous EPSCs, and a loss of polyamine‐sensitive inward rectification, all supportive of an increase in heteromeric AMPAR channels containing the GluR2 subunit. Phosphorylation of GluR2 at serine 880 in both saline‐treated and MPTP mice suggests that exercise may also influence AMPAR trafficking and thus synaptic strength within the striatum. Finally, treadmill exercise also altered flip isoforms of GluR2 and GluR1 mRNA transcripts. These findings suggest a role for AMPARs in mediating the beneficial effects of exercise and support the idea that adaptive changes in GluR2 subunit expression may be important in modulating experience‐dependent neuroplasticity of the injured basal ganglia. © 2009 Wiley‐Liss, Inc.
Features of sequential learning in hemicerebellectomized rats
Authors: Mandolesi L. , Foti F. , Cutuli D. , Laricchiuta D. , Gelfo F. , De Bartolo P. , Petrosini L.
Published: September 2009

Because the sequencing property is one of the functions in which cerebellar circuits are involved, it is important to analyze the features of sequential learning in the presence of cerebellar damage. Hemicerebellectomized and control rats were tested in a four‐choice visuomotor learning task that required both the detection of a specific sequence of correct choices and the acquisition of procedural rules about how to perform the task. The findings indicate that the presence of the hemicerebellectomy did not affect the first phases of detection and acquisition of the sequential visuomotor task, delayed but did not prevent the learning of the sequential task, slowed down speed‐up and proceduralization phases, and loosened the reward‐response associative structure. The performances of hemicerebellectomized animals in the serial learning task as well as in the open field task demonstrated that the delayed sequential learning task could not be ascribed to impairment of motor functions or discriminative abilities or to low levels of motivation. The delay in sequential learning observed in the presence of a cerebellar lesion appeared to be related mainly to a delay of the automatization of the response. In conclusion, it may be advanced that, through cortical and subcortical connections, the cerebellum provides the acquisition of rapid and accurate sensory‐guided sequence of responses. © 2009 Wiley‐Liss, Inc.
Theory of the evolution of 2D band in the Raman spectra of monolayer and bilayer graphene with laser excitation energy
Authors: Wang Hui , You Jinghan , Wang Lin , Feng Min , Wang Yufang
Published: September 2009

A double‐resonance process gives rise to the 2D band in the Raman spectra of monolayer and bilayer graphene. Based on the electronic and vibrational dispersion energies of graphene, the wavenumbers of the 2D band were calculated under different laser excitation energies (from 1.0 to 4.4 eV). Calculated results are in good agreement with experimental data and reproduce the experimental dispersion slope of the 2D band very well. The calculated wavenumbers of the 2D band do not show a linear dependence on the laser excitation energies. Moreover, it is explained that the lowest wavenumber peak of the 2D band of the bilayer graphene, which is composed of four components, has the largest slope with laser excitation energy. Copyright © 2009 John Wiley & Sons, Ltd.
Capillary electrophoretic enantioseparation of m‐nisoldipine using two different β‐cyclodextrins
Authors: Kong Dezhi , Yang Wei , Duan Kunfeng , Cui Yang , Xing Songsong , Zhang Xiaowei , Sheng Xiaona , Zhang Lantong
Published: September 2009

The methods for the enantioseparation of m‐nisoldipine, a new 1,4‐dihydropyridine calcium ion antagonist, were developed. The elaborated methods of m‐nisoldipine enantiomers separation were successfully performed using an anionic CD–sulfobutyl ether‐β‐CD (SBE‐β‐CD) or carboxymethyl‐β‐CD as chiral selector. However, the results indicated that SBE‐β‐CD was a better chiral selector for enantioseparation of the neutral m‐nisoldipine. Furthermore, comparing the two SBE‐β‐CDs, the derivative with a higher degree of substitution (DS) of 7.0 induced better enantioresolution than the one with low DS (4.0). In addition, possible chiral recognition mechanisms of dihydropyridines were discussed.
Preparation of terbutylazine imprinted polymer microspheres using viscous polymerization solvents
Authors: Horváth Viola , Lorántfy Bettina , Tóth Blanka , Bognár Júlia , László Krisztina , Horvai George
Published: September 2009

Spherical micron sized terbutylazine imprinted polymers have been obtained by copolymerization of acrylates in solvent mixtures containing a highly viscous (‘oil’) component. The new method requires much less organic solvent than precipitation polymerization to produce spherical MIP particles. Different proportions of oil have been used to clarify its role on the morphology. The particles obtained with the optimal composition could be easily packed into short HPLC columns. Chromatographic retention of the template and other compounds has been determined on the novel (‘OMIP’) columns and was compared to MIP prepared by bulk polymerization. In 70% aqueous acetonitrile eluent the OMIP shows a higher imprinting factor (i. e. less non‐selective binding) and lower retention than the bulk MIP. The chromatographic selectivity against template analogs is similar on OMIP and bulk MIP, while the selectivity against non‐related substances is better on the OMIP. The effect of oil on the polymer structure appears to be due to its high viscosity.
Effects of variation in modulator temperature during cryogenic modulation in comprehensive two‐dimensional gas chromatography
Authors: Begnaud Frédéric , Debonneville Christian , Probst Jean‐Pierre , Chaintreau Alain , Morrison Paul D. , Adcock Jacqui L. , Marriott Philip J.
Published: September 2009

Many modulation systems in comprehensive 2D GC (GC×GC) are based on cryogenic methods. High trapping temperatures in these systems can result in ineffective trapping of the more volatile compounds, whilst temperatures that are too low can prevent efficient remobilisation of some compounds. To better understand the trapping and release of compounds over a wide range of volatilities, we have investigated a number of different constant temperature modulator settings, and have also examined a constant temperature differential between the cryo‐trap and the chromatographic oven. These investigations have led us to modify the temperature regulation capabilities of the longitudinally modulated cryogenic system (LMCS). In contrast to the current system, where the user sets a constant temperature for the cooling chamber, the user now sets the temperature difference between the cryo‐trap and the chromatographic oven. In this configuration, the cooling chamber temperature increases during the chromatographic run, tracking the oven temperature ramp. This produces more efficient, volatility‐dependent modulation, and increases the range of volatile compounds that can be analysed under optimal trap‐and‐release conditions within a single analytical run. This system also reduces cryogenic fluid consumption.