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  1. Molecular alterations and biomarkers in colorectal cancer

    PubMed Central

    Grady, William M.; Pritchard, Colin C.

    2013-01-01

    The promise of precision medicine is now a clinical reality. Advances in our understanding of the molecular genetics of colorectal cancer genetics is leading to the development of a variety of biomarkers that are being used as early detection markers, prognostic markers, and markers for predicting treatment responses. This is no more evident than in the recent advances in testing colorectal cancers for specific molecular alterations in order to guide treatment with the monoclonal antibody therapies cetuximab and panitumumab, which target the epidermal growth factor receptor (EGFR). In this review, we update a prior review published in 2010 and describe our current understanding of the molecular pathogenesis of colorectal cancer and how these alterations relate to emerging biomarkers for early detection and risk stratification (diagnostic markers), prognosis (prognostic markers), and the prediction of treatment responses (predictive markers). PMID:24178577

  2. Epigenetic Alterations in Colorectal Cancer: Emerging Biomarkers

    PubMed Central

    Okugawa, Yoshinaga; Grady, William M.; Goel, Ajay

    2015-01-01

    Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. One of the fundamental processes driving the initiation and progression of CRC is the accumulation of a variety of genetic and epigenetic changes in colon epithelial cells. Over the past decade, major advances have been made in our understanding of cancer epigenetics, particularly regarding aberrant DNA methylation, microRNA (miRNA) and noncoding RNA deregulation, and alterations in histone modification states. Assessment of the colon cancer “epigenome” has revealed that virtually all CRCs have aberrantly methylated genes and altered miRNA expression. The average CRC methylome has hundreds to thousands of abnormally methylated genes and dozens of altered miRNAs. As with gene mutations in the cancer genome, a subset of these epigenetic alterations, called driver events, is presumed to have a functional role in CRC. In addition, the advances in our understanding of epigenetic alterations in CRC have led to these alterations being developed as clinical biomarkers for diagnostic, prognostic and therapeutic applications. Progress in this field suggests that these epigenetic alterations will be commonly used in the near future to direct the prevention and treatment of CRC. PMID:26216839

  3. Human papillomavirus DNA and oncogene alterations in colorectal tumors.

    PubMed

    Pérez, Luis Orlando; Barbisan, Gisela; Ottino, Anabel; Pianzola, Horacio; Golijow, Carlos Daniel

    2010-09-01

    The aim of the present study is to determine the presence and molecular integrity of high-risk HPV types in colorectal adenocarcinomas and to assess whether viral DNA is related to common proto-oncogene alterations, such as k-ras mutations and c-myc gene amplification, in colorectal cancer. Seventy-five colorectal adenocarcinomas were screened for HPV infection using nested-PCR (MY09/11-GP5+/6+). HPV typing was performed by type-specific PCR for HPV 16 and HPV 18 DNA. Unidentified samples were subsequently sequenced to determine the viral genotype. The physical status of HPV was determined by a nested PCR approach for type-specific E2 sequences. C-myc amplification was assessed by co-amplification with β-globin as control locus, and mutation in k-ras codons 12 and 13 by ARMS-PCR. Overall, HPV was detected in thirty-three colorectal specimens (44%). HPV 16 was the prevalent type (16/75), followed by HPV 18 (15/75), HPV 31 (1/75) and HPV 66 (1/75). E2 disruption was detected in 56.3% of HPV 16 and in 40% of HPV 18 positive tumors. C-myc amplification was detected in 29.4% of cases, while k-ras mutations in 30.7%. There was no significant trend for HPV infection in tumors harboring either k-ras or c-myc alterations. This study demonstrates HPV DNA and viral integration in colorectal tumors, suggesting a potential role of this virus in colorectal carcinogenesis. There was no concurrence, however, of k-ras and c-myc activation with viral infection.

  4. Distinct Genetic Alterations in Colorectal Cancer

    PubMed Central

    Ashktorab, Hassan; Schäffer, Alejandro A.; Daremipouran, Mohammad; Smoot, Duane T.; Lee, Edward; Brim, Hassan

    2010-01-01

    Background Colon cancer (CRC) development often includes chromosomal instability (CIN) leading to amplifications and deletions of large DNA segments. Epidemiological, clinical, and cytogenetic studies showed that there are considerable differences between CRC tumors from African Americans (AAs) and Caucasian patients. In this study, we determined genomic copy number aberrations in sporadic CRC tumors from AAs, in order to investigate possible explanations for the observed disparities. Methodology/Principal Findings We applied genome-wide array comparative genome hybridization (aCGH) using a 105k chip to identify copy number aberrations in samples from 15 AAs. In addition, we did a population comparative analysis with aCGH data in Caucasians as well as with a widely publicized list of colon cancer genes (CAN genes). There was an average of 20 aberrations per patient with more amplifications than deletions. Analysis of DNA copy number of frequently altered chromosomes revealed that deletions occurred primarily in chromosomes 4, 8 and 18. Chromosomal duplications occurred in more than 50% of cases on chromosomes 7, 8, 13, 20 and X. The CIN profile showed some differences when compared to Caucasian alterations. Conclusions/Significance Chromosome X amplification in male patients and chromosomes 4, 8 and 18 deletions were prominent aberrations in AAs. Some CAN genes were altered at high frequencies in AAs with EXOC4, EPHB6, GNAS, MLL3 and TBX22 as the most frequently deleted genes and HAPLN1, ADAM29, SMAD2 and SMAD4 as the most frequently amplified genes. The observed CIN may play a distinctive role in CRC in AAs. PMID:20126641

  5. Epigenetic Alterations in Colorectal Cancer: Emerging Biomarkers.

    PubMed

    Okugawa, Yoshinaga; Grady, William M; Goel, Ajay

    2015-10-01

    Colorectal cancer (CRC) is a leading cause of cancer deaths worldwide. One of the fundamental processes driving the initiation and progression of CRC is the accumulation of a variety of genetic and epigenetic changes in colonic epithelial cells. Over the past decade, major advances have been made in our understanding of cancer epigenetics, particularly regarding aberrant DNA methylation, microRNA (miRNA) and noncoding RNA deregulation, and alterations in histone modification states. Assessment of the colon cancer "epigenome" has revealed that virtually all CRCs have aberrantly methylated genes and altered miRNA expression. The average CRC methylome has hundreds to thousands of abnormally methylated genes and dozens of altered miRNAs. As with gene mutations in the cancer genome, a subset of these epigenetic alterations, called driver events, are presumed to have a functional role in CRC. In addition, the advances in our understanding of epigenetic alterations in CRC have led to these alterations being developed as clinical biomarkers for diagnostic, prognostic, and therapeutic applications. Progress in this field suggests that these epigenetic alterations will be commonly used in the near future to direct the prevention and treatment of CRC.

  6. Detection of genetic alterations in hereditary colorectal cancer screening.

    PubMed

    Pineda, Marta; González, Sara; Lázaro, Conxi; Blanco, Ignacio; Capellá, Gabriel

    2010-11-10

    There are two major hereditary colorectal cancer syndromes: Adenomatous Polyposis, secondary to APC germline alterations (FAP, Familial Adenomatous Polyposis) or secondary to MUTYH germline alterations (MAP, MUTYH associated Polyposis), and Lynch syndrome, associated with germline mutations in mismatch repair genes (MLH1, MSH2, MSH6 and PMS2). The elucidation of their genetic basis has depicted an increasingly complex picture that has lead to the implementation of complex diagnostic algorithms that include both tumor profiling and germline analyses. A variety of techniques at the DNA, RNA and protein level are used to screen for molecular alterations both in tumor biopsies (microsatellite instability analysis, mismatch repair protein immunohistochemistry, BRAF-Val600Glu detection and MLH1 promoter hypermethylation analysis) and in the germline (point mutation screening, copy number assessment). Also functional tests are more often used to characterize variants of unknown significance. Methodological issues associated with the techniques analyzed, as well as the algorithms used, are discussed. 2009 Elsevier B.V. All rights reserved.

  7. Altered RECQ Helicase Expression in Sporadic Primary Colorectal Cancers.

    PubMed

    Lao, Victoria Valinluck; Welcsh, Piri; Luo, Yanxin; Carter, Kelly T; Dzieciatkowski, Slavomir; Dintzis, Suzanne; Meza, Jane; Sarvetnick, Nora E; Monnat, Raymond J; Loeb, Lawrence A; Grady, William M

    2013-08-01

    Deregulation of DNA repair enzymes occurs in cancers and may create a susceptibility to chemotherapy. Expression levels of DNA repair enzymes have been shown to predict the responsiveness of cancers to certain chemotherapeutic agents. The RECQ helicases repair damaged DNA including damage caused by topoisomerase I inhibitors, such as irinotecan. Altered expression levels of these enzymes in colorectal cancer (CRC) may influence the response of the cancers to irinotecan. Thus, we assessed RECQ helicase (WRN, BLM, RECQL, RECQL4, and RECQL5) expression in primary CRCs, matched normal colon, and CRC cell lines. We found that BLM and RECQL4 mRNA levels are significantly increased in CRC (P = .0011 and P < .0001, respectively), whereas RECQL and RECQL5 are significantly decreased (P = .0103 and P = .0029, respectively). RECQ helicase expression patterns varied between specific molecular subtypes of CRCs. The mRNA and protein expression of the majority of the RECQ helicases was closely correlated, suggesting that altered mRNA expression is the predominant mechanism for deregulated RECQ helicase expression. Immunohistochemistry localized the RECQ helicases to the nucleus. RECQ helicase expression is altered in CRC, suggesting that RECQ helicase expression has potential to identify CRCs that are susceptible to specific chemotherapeutic agents.

  8. Altered JS-2 expression in colorectal cancers and its clinical pathological relevance.

    PubMed

    Lam, Alfred King-Yin; Gopalan, Vinod; Nassiri, Mohammad Reza; Kasim, Kais; Dissanayake, Jayampathy; Tang, Johnny Chuek-On; Smith, Robert Anthony

    2011-10-01

    JS-2 is a novel gene located at 5p15.2 and originally detected in primary oesophageal cancer. There is no study on the role of JS-2 in colorectal cancer. The aim of this study is to determine the gene copy number and expression of JS-2 in a large cohort of patients with colorectal tumours and correlate these to the clinicopathological features of the cancer patients. We evaluated the DNA copy number and mRNA expression of JS-2 in 176 colorectal tissues (116 adenocarcinomas, 30 adenomas and 30 non-neoplastic tissues) using real-time polymerase chain reaction. JS-2 expression was also evaluated in two colorectal cancer cell lines and a benign colorectal cell line. JS-2 amplification was noted in 35% of the colorectal adenocarcinomas. Significant differences in relative expression levels for JS-2 mRNA between different colorectal tissues were noted (p = 0.05). Distal colorectal adenocarcinoma had significantly higher copy number than proximal adenocarcinoma (p = 0.005). The relative expression level of JS-2 was different between colonic and rectal adenocarcinoma (p = 0.007). Mucinous adenocarcinoma showed higher JS-2 expression than non-mucinous adenocarcinoma (p = 0.02). Early T-stage cancers appear to have higher JS-2 copy number and lower expression of JS-2 mRNA than later stage cancers (p = 0.001 and 0.03 respectively). Colorectal cancer cell lines showed lower expression of JS-2 than the benign colorectal cell line. JS-2 copy number change and expression were shown for the first time to be altered in the carcinogenesis of colorectal cancer. In addition, genetic alteration of JS-2 was found to be related to location, pathological subtypes and staging of colorectal cancer.

  9. Transporter function and cyclic AMP turnover in normal colonic mucosa from patients with and without colorectal neoplasia.

    PubMed

    Kleberg, Karen; Jensen, Gerda Majgaard; Christensen, Dan Ploug; Lundh, Morten; Grunnet, Lars Groth; Knuhtsen, Svend; Poulsen, Steen Seier; Hansen, Mark Berner; Bindslev, Niels

    2012-06-26

    The pathogenesis of colorectal neoplasia is still unresolved but has been associated with alterations in epithelial clearance of xenobiotics and metabolic waste products. The aim of this study was to functionally characterize the transport of cyclic nucleotides in colonic biopsies from patients with and without colorectal neoplasia. Cyclic nucleotides were used as model substrates shared by some OATP- and ABC-transporters, which in part are responsible for clearance of metabolites and xenobiotics from the colonic epithelium. On colonic biopsies from patients with and without colorectal neoplasia, molecular transport was electrophysiologically registered in Ussing-chamber set-ups, mRNA level of selected transporters was quantified by rt-PCR, and subcellular location of transporters was determined by immunohistochemistry. Of four cyclic nucleotides, dibuturyl-cAMP induced the largest short circuit current in both patient groups. The induced short circuit current was significantly lower in neoplasia-patients (p = 0.024). The observed altered transport of dibuturyl-cAMP in neoplasia-patients could not be directly translated to an observed increased mRNA expression of OATP4A1 and OATP2B1 in neoplasia patients. All other examined transporters were expressed to similar extents in both patient groups. OATP1C1, OATP4A1, OATP4C1 seem to be involved in the excretory system of human colon. ABCC4 is likely to be involved from an endoplasmic-Golgi complex and basolateral location in goblet cells. ABCC5 might be directly involved in the turnover of intracellular cAMP at the basolateral membrane of columnar epithelial cells, while OATP2B1 is indirectly related to the excretory system. Colorectal neoplasia is associated with lower transport or sensitivity to cyclic nucleotides and increased expression of OATP2B1 and OATP4A1 transporters, known to transport PGE(2).

  10. Transporter function and cyclic AMP turnover in normal colonic mucosa from patients with and without colorectal neoplasia

    PubMed Central

    2012-01-01

    Background The pathogenesis of colorectal neoplasia is still unresolved but has been associated with alterations in epithelial clearance of xenobiotics and metabolic waste products. The aim of this study was to functionally characterize the transport of cyclic nucleotides in colonic biopsies from patients with and without colorectal neoplasia. Methods Cyclic nucleotides were used as model substrates shared by some OATP- and ABC-transporters, which in part are responsible for clearance of metabolites and xenobiotics from the colonic epithelium. On colonic biopsies from patients with and without colorectal neoplasia, molecular transport was electrophysiologically registered in Ussing-chamber set-ups, mRNA level of selected transporters was quantified by rt-PCR, and subcellular location of transporters was determined by immunohistochemistry. Results Of four cyclic nucleotides, dibuturyl-cAMP induced the largest short circuit current in both patient groups. The induced short circuit current was significantly lower in neoplasia-patients (p = 0.024). The observed altered transport of dibuturyl-cAMP in neoplasia-patients could not be directly translated to an observed increased mRNA expression of OATP4A1 and OATP2B1 in neoplasia patients. All other examined transporters were expressed to similar extents in both patient groups. Conclusions OATP1C1, OATP4A1, OATP4C1 seem to be involved in the excretory system of human colon. ABCC4 is likely to be involved from an endoplasmic-Golgi complex and basolateral location in goblet cells. ABCC5 might be directly involved in the turnover of intracellular cAMP at the basolateral membrane of columnar epithelial cells, while OATP2B1 is indirectly related to the excretory system. Colorectal neoplasia is associated with lower transport or sensitivity to cyclic nucleotides and increased expression of OATP2B1 and OATP4A1 transporters, known to transport PGE2. PMID:22734885

  11. Association of Fusobacterium nucleatum with immunity and molecular alterations in colorectal cancer.

    PubMed

    Nosho, Katsuhiko; Sukawa, Yasutaka; Adachi, Yasushi; Ito, Miki; Mitsuhashi, Kei; Kurihara, Hiroyoshi; Kanno, Shinichi; Yamamoto, Itaru; Ishigami, Keisuke; Igarashi, Hisayoshi; Maruyama, Reo; Imai, Kohzoh; Yamamoto, Hiroyuki; Shinomura, Yasuhisa

    2016-01-14

    The human intestinal microbiome plays a major role in human health and diseases, including colorectal cancer. Colorectal carcinogenesis represents a heterogeneous process with a differing set of somatic molecular alterations, influenced by diet, environmental and microbial exposures, and host immunity. Fusobacterium species are part of the human oral and intestinal microbiota. Metagenomic analyses have shown an enrichment of Fusobacterium nucleatum (F. nucleatum) in colorectal carcinoma tissue. Using 511 colorectal carcinomas from Japanese patients, we assessed the presence of F. nucleatum. Our results showed that the frequency of F. nucleatum positivity in the Japanese colorectal cancer was 8.6% (44/511), which was lower than that in United States cohort studies (13%). Similar to the United States studies, F. nucleatum positivity in Japanese colorectal cancers was significantly associated with microsatellite instability (MSI)-high status. Regarding the immune response in colorectal cancer, high levels of infiltrating T-cell subsets (i.e., CD3+, CD8+, CD45RO+, and FOXP3+ cells) have been associated with better patient prognosis. There is also evidence to indicate that molecular features of colorectal cancer, especially MSI, influence T-cell-mediated adaptive immunity. Concerning the association between the gut microbiome and immunity, F. nucleatum has been shown to expand myeloid-derived immune cells, which inhibit T-cell proliferation and induce T-cell apoptosis in colorectal cancer. This finding indicates that F. nucleatum possesses immunosuppressive activities by inhibiting human T-cell responses. Certain microRNAs are induced during the macrophage inflammatory response and have the ability to regulate host-cell responses to pathogens. MicroRNA-21 increases the levels of IL-10 and prostaglandin E2, which suppress antitumor T-cell-mediated adaptive immunity through the inhibition of the antigen-presenting capacities of dendritic cells and T-cell proliferation in

  12. Association of Fusobacterium nucleatum with immunity and molecular alterations in colorectal cancer

    PubMed Central

    Nosho, Katsuhiko; Sukawa, Yasutaka; Adachi, Yasushi; Ito, Miki; Mitsuhashi, Kei; Kurihara, Hiroyoshi; Kanno, Shinichi; Yamamoto, Itaru; Ishigami, Keisuke; Igarashi, Hisayoshi; Maruyama, Reo; Imai, Kohzoh; Yamamoto, Hiroyuki; Shinomura, Yasuhisa

    2016-01-01

    The human intestinal microbiome plays a major role in human health and diseases, including colorectal cancer. Colorectal carcinogenesis represents a heterogeneous process with a differing set of somatic molecular alterations, influenced by diet, environmental and microbial exposures, and host immunity. Fusobacterium species are part of the human oral and intestinal microbiota. Metagenomic analyses have shown an enrichment of Fusobacterium nucleatum (F. nucleatum) in colorectal carcinoma tissue. Using 511 colorectal carcinomas from Japanese patients, we assessed the presence of F. nucleatum. Our results showed that the frequency of F. nucleatum positivity in the Japanese colorectal cancer was 8.6% (44/511), which was lower than that in United States cohort studies (13%). Similar to the United States studies, F. nucleatum positivity in Japanese colorectal cancers was significantly associated with microsatellite instability (MSI)-high status. Regarding the immune response in colorectal cancer, high levels of infiltrating T-cell subsets (i.e., CD3+, CD8+, CD45RO+, and FOXP3+ cells) have been associated with better patient prognosis. There is also evidence to indicate that molecular features of colorectal cancer, especially MSI, influence T-cell-mediated adaptive immunity. Concerning the association between the gut microbiome and immunity, F. nucleatum has been shown to expand myeloid-derived immune cells, which inhibit T-cell proliferation and induce T-cell apoptosis in colorectal cancer. This finding indicates that F. nucleatum possesses immunosuppressive activities by inhibiting human T-cell responses. Certain microRNAs are induced during the macrophage inflammatory response and have the ability to regulate host-cell responses to pathogens. MicroRNA-21 increases the levels of IL-10 and prostaglandin E2, which suppress antitumor T-cell-mediated adaptive immunity through the inhibition of the antigen-presenting capacities of dendritic cells and T-cell proliferation in

  13. Altered tissue metabolites correlate with microbial dysbiosis in colorectal adenomas.

    PubMed

    Nugent, Julia L; McCoy, Amber N; Addamo, Cassandra J; Jia, Wei; Sandler, Robert S; Keku, Temitope O

    2014-04-04

    Several studies have linked bacterial dysbiosis with elevated risk of colorectal adenomas and cancer. However, the functional implications of gut dysbiosis remain unclear. Gut bacteria contribute to nutrient metabolism and produce small molecules termed the "metabolome", which may contribute to the development of neoplasia in the large bowel. We assessed the metabolome in normal rectal mucosal biopsies of 15 subjects with colorectal adenomas and 15 nonadenoma controls by liquid chromatography and gas chromatography time-of-flight mass spectrometry. Quantitative real-time PCR was used to measure abundances of specific bacterial taxa. We identified a total of 274 metabolites. Discriminant analysis suggested a separation of metabolomic profiles between adenoma cases and nonadenoma controls. Twenty-three metabolites contributed to the separation, notably an increase in adenoma cases of the inflammatory metabolite prostaglandin E2 and a decrease in antioxidant-related metabolites 5-oxoproline and diketogulonic acid. Pathway analysis suggested that differential metabolites were significantly related to cancer, inflammatory response, carbohydrate metabolism, and GI disease pathways. Abundances of six bacterial taxa assayed were increased in cases. The 23 differential metabolites demonstrated correlations with bacteria that were different between cases and controls. These findings suggest that metabolic products of bacteria may be responsible for the development of colorectal adenomas and CRC.

  14. Altered Activity and Expression of Cytosolic Peptidases in Colorectal Cancer

    PubMed Central

    Perez, Itxaro; Blanco, Lorena; Sanz, Begoña; Errarte, Peio; Ariz, Usue; Beitia, Maider; Fernández, Ainhoa; Loizate, Alberto; Candenas, M Luz; Pinto, Francisco M; Gil, Javier; López, José I.; Larrinaga, Gorka

    2015-01-01

    Background and Objective: The role of peptidases in carcinogenic processes and their potential usefulness as tumor markers in colorectal cancer (CRC) have been classically attributed to cell-surface enzymes. The objective of the present study was to analyze the activity and mRNA expression of three cytosolic peptidases in the CRC and to correlate the obtained results with classic histopathological parameters for tumor prognosis and survival. Methods: The activity and mRNA levels of puromycin-sensitive aminopeptidase (PSA), aminopeptidase B (APB) and pyroglutamyl-peptidase I (PGI) were measured by fluorimetric and quantitative RT-PCR methods in colorectal mucosa and tumor tissues and plasma samples from CRC patients (n=81). Results: 1) PSA and APB activity was higher in adenomas and carcinomas than in the uninvolved mucosa. 2) mRNA levels of PSA and PGI was lower in tumors. 3) PGI activity in CRC tissue correlated negatively with histological grade, tumor size and 5-year overall suvival of CRC patients. 4) Higher plasmatic APB activity was independently associated with better 5-year overall survival. Conclusions: Data suggest that cytosolic peptidases may be involved in colorectal carcinogenesis and point to the determination of this enzymes as a valuable method in the determination of CRC prognosis. PMID:26078706

  15. Frequent alteration of the tumor suppressor gene APC in sporadic canine colorectal tumors.

    PubMed

    Youmans, Lydia; Taylor, Cynthia; Shin, Edwin; Harrell, Adrienne; Ellis, Angela E; Séguin, Bernard; Ji, Xinglai; Zhao, Shaying

    2012-01-01

    Sporadic canine colorectal cancers (CRCs) should make excellent models for studying the corresponding human cancers. To molecularly characterize canine CRC, we investigated exonic sequence mutations of adenomatous polyposis coli (APC), the best known tumor suppressor gene of human CRC, in 23 sporadic canine colorectal tumors, including 8 adenomas and 15 adenocarcinomas, via exon-resequencing analysis. As a comparison, we also performed the same sequencing analysis on 10 other genes, either located at human 5q22 (the same locus as APC) or 18q21 (also frequently altered in human CRC), or known to play a role in human carcinogenesis. We noted that APC was the most significantly mutated gene in both canine adenomas and adenocarcinomas among the 11 genes examined. Significantly, we detected large deletions of ≥ 10 bases, many clustered near the mutation cluster region, as well as single or two base deletions in ~70% canine tumors of both subtypes. These observations indicate that like in the human, APC is also frequently altered in sporadic colorectal tumors in the dog and its alteration is an early event in canine colorectal tumorigenesis. Our study provides further evidence demonstrating the molecular similarity in pathogenesis between sporadic human and canine CRCs. This work, along with our previous copy number abnormality study, supports that sporadic canine CRCs are valid models of human CRCs at the molecular level.

  16. Drug transporter gene expression in human colorectal tissue and cell lines: modulation with antiretrovirals for microbicide optimization.

    PubMed

    Mukhopadhya, Indrani; Murray, Graeme I; Berry, Susan; Thomson, John; Frank, Bruce; Gwozdz, Garry; Ekeruche-Makinde, Julia; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

    2016-02-01

    The objectives of this study were to comprehensively assess mRNA expression of 84 drug transporters in human colorectal biopsies and six representative cell lines, and to investigate the alteration of drug transporter gene expression after exposure to three candidate microbicidal antiretroviral (ARV) drugs (tenofovir, darunavir and dapivirine) in the colorectal epithelium. The outcome of the objectives informs development of optimal ARV-based microbicidal formulations for prevention of HIV-1 infection. Drug transporter mRNA expression was quantified from colorectal biopsies and cell lines by quantitative real-time PCR. Relative mRNA expression was quantified in Caco-2 cells and colorectal explants after induction with ARVs. Data were analysed using Pearson's product moment correlation (r), hierarchical clustering and principal component analysis (PCA). Expression of 58 of the 84 transporters was documented in colorectal biopsies, with genes for CNT2, P-glycoprotein (P-gp) and MRP3 showing the highest expression. No difference was noted between individual subjects when analysed by age, gender or anatomical site (rectum or recto-sigmoid) (r = 0.95-0.99). High expression of P-gp and CNT2 proteins was confirmed by immunohistochemical staining. Similarity between colorectal tissue and cell-line drug transporter gene expression was variable (r = 0.64-0.84). PCA showed distinct clustering of human colorectal biopsy samples, with the Caco-2 cells defined as the best surrogate system. Induction of Caco-2 cell lines with ARV drugs suggests that darunavir-based microbicides incorporating tenofovir may result in drug-drug interactions likely to affect distribution of individual drugs to sub-epithelial target cells. These findings will help optimize complex formulations of rectal microbicides to realize their full potential as an effective approach for pre-exposure prophylaxis against HIV-1 infection. © The Author 2015. Published by Oxford University Press on behalf of the

  17. p53 gene alterations and protein accumulation in colorectal cancer

    PubMed Central

    Bertorelle, R; Esposito, G; Belluco, C; Bonaldi, L; Del Mistro, A; Nitti, D; Lise, M; Chieco-Bianchi, L

    1996-01-01

    Aim—To correlate immunohistochemical staining with single strand conformation polymorphism (SSCP) analysis of the p53 gene in colorectal cancer in order to understand how the findings provided by the two techniques complement each other in defining p53 functional status. Methods—Frozen tumour tissue from 94 patients with colorectal cancer was studied for p53 protein accumulation and gene mutations. Accumulation of p53 protein was detected by immunohistochemistry using PAb1801 and BP53-12-1 monoclonal antibodies. The findings were then compared with SSCP analysis of exons 5 to 8 of the p53 gene. All cases with a positive result by SSCP analysis were confirmed by sequencing. Results—Nuclear staining was observed in 51 (54.2%) cases. SSCP analysis of the DNA amplified by PCR revealed that the electrophoretic pattern had shifted in 30 cases; sequence analysis confirmed the occurrence of a mutation in 29 cases and of a polymorphism in one. In 27 cases both assays gave a positive result, and in 40 both were negative; therefore, concordance between PCR-SSCP and immunohistochemistry was seen in 72% of cases. Conclusion—The data indicate that positive immunostaining corresponds with the presence of a mutation in most, but not all, cases studied; other mechanisms could be responsible for stabilisation and accumulation of p53 protein in the nucleus. Nonsense mutations which do not confer stability on the protein will not be detected by immunohistochemistry and false negative results can also occur with SSCP analysis. Images PMID:16696056

  18. High frequency of altered HLA class I phenotypes in invasive colorectal carcinomas.

    PubMed

    Cabrera, T; Collado, A; Fernandez, M A; Ferron, A; Sancho, J; Ruiz-Cabello, F; Garrido, F

    1998-08-01

    We analyzed the expression of HLA class I antigens in 78 tumor tissue samples obtained from patients diagnosed as having colorectal carcinomas. A broad panel of mAbs defining HLA monomorphic, locus-specific and allele-specific determinants was used. In addition, an antibody defining HLA-C locus-specific determinant (L31) was also tested. Previous reports on these tumors indicated HLA class I losses of 30 to 40%. At least 73% of the patients in the present study had a detectable HLA class I alteration. These altered HLA phenotypes were classified as total HLA loss (18%) (phenotype I); HLA-A locus-specific loss (9%) (phenotype IIIa); HLA-B locus-specific loss (8%) (phenotype IIIb); HLA-A and B locus losses (2%) and HLA allelic losses (36%) (phenotype IV). We found no HLA-C locus losses. Autologous peripheral blood lymphocyte HLA class I typing was always necessary to define phenotype IV. We also studied the CD3 zeta chain in tumor tissues to correlate possible changes in the CD3 signal transduction pathway with HLA alterations. The CD3 ratio was frequently altered, but this alteration could not be correlated with tumor HLA phenotypes. The high frequency of HLA class I losses in colorectal carcinomas suggests that this finding is a widespread phenomenon and may be required to escape T-cell recognition. It remains to be determined whether HLA expression is "normal" in the rest of the 27% of our patients.

  19. DNA fingerprinting techniques for the analysis of genetic and epigenetic alterations in colorectal cancer.

    PubMed

    Samuelsson, Johanna K; Alonso, Sergio; Yamamoto, Fumiichiro; Perucho, Manuel

    2010-11-10

    Genetic somatic alterations are fundamental hallmarks of cancer. In addition to point and other small mutations targeting cancer genes, solid tumors often exhibit aneuploidy as well as multiple chromosomal rearrangements of large fragments of the genome. Whether somatic chromosomal alterations and aneuploidy are a driving force or a mere consequence of tumorigenesis remains controversial. Recently it became apparent that not only genetic but also epigenetic alterations play a major role in carcinogenesis. Epigenetic regulation mechanisms underlie the maintenance of cell identity crucial for development and differentiation. These epigenetic regulatory mechanisms have been found substantially altered during cancer development and progression. In this review, we discuss approaches designed to analyze genetic and epigenetic alterations in colorectal cancer, especially DNA fingerprinting approaches to detect changes in DNA copy number and methylation. DNA fingerprinting techniques, despite their modest throughput, played a pivotal role in significant discoveries in the molecular basis of colorectal cancer. The aim of this review is to revisit the fingerprinting technologies employed and the oncogenic processes that they unveiled. 2010 Elsevier B.V. All rights reserved.

  20. DNA Fingerprinting Techniques for the Analysis of Genetic and Epigenetic Alterations in Colorectal Cancer

    PubMed Central

    Samuelsson, Johanna K.; Alonso, Sergio; Yamamoto, Fumiichiro; Perucho, Manuel

    2010-01-01

    Genetic somatic alterations are fundamental hallmarks of cancer. In addition to point and other small mutations targeting cancer genes, solid tumors often exhibit aneuploidy as well as multiple chromosomal rearrangements of large fragments of the genome. Whether somatic chromosomal alterations and aneuploidy are a driving force or a mere consequence of tumorigenesis remains controversial. Recently it became apparent that not only genetic but also epigenetic alterations play a major role in carcinogenesis. Epigenetic regulation mechanisms underlie the maintenance of cell identity crucial for development and differentiation. These epigenetic regulatory mechanisms have been found substantially altered during cancer development and progression. In this review, we discuss approaches designed to analyze genetic and epigenetic alterations in colorectal cancer, especially DNA fingerprinting approaches to detect changes in DNA copy number and methylation. DNA fingerprinting techniques, despite their modest throughput, played a pivotal role in significant discoveries in the molecular basis of colorectal cancer. The aim of this review is to revisit the fingerprinting technologies employed and the oncogenic processes that they unveiled. PMID:20851135

  1. PIK3CA Mutation in Colorectal Cancer: Relationship with Genetic and Epigenetic Alterations1

    PubMed Central

    Nosho, Katsuhiko; Kawasaki, Takako; Ohnishi, Mutsuko; Suemoto, Yuko; Kirkner, Gregory J; Zepf, Dimity; Yan, Liying; Longtine, Janina A; Fuchs, Charles S; Ogino, Shuji

    2008-01-01

    Somatic PIK3CA mutations are often present in colorectal cancer. Mutant PIK3CA activates AKT signaling, which up-regulates fatty acid synthase (FASN). Microsatellite instability (MSI) and CpG island methylator phenotype (CIMP) are important molecular classifiers in colorectal cancer. However, the relationship between PIK3CA mutation, MSI and CIMP remains uncertain. Using Pyrosequencing technology, we detected PIK3CA mutations in 91 (15%) of 590 population-based colorectal cancers. To determine CIMP status, we quantified DNA methylation in eight CIMP-specific promoters [CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1] by real-time polymerase chain reaction (MethyLight). PIK3CA mutation was significantly associated with mucinous tumors [P = .0002; odds ratio (OR) = 2.44], KRAS mutation (P < .0001; OR = 2.68), CIMP-high (P = .03; OR = 2.08), phospho-ribosomal protein S6 expression (P = .002; OR = 2.19), and FASN expression (P = .02; OR = 1.85) and inversely with p53 expression (P = .01; OR = 0.54) and β-catenin (CTNNB1) alteration (P = .004; OR = 0.43). In addition, PIK3CA G-to-A mutations were associated with MGMT loss (P = .001; OR = 3.24) but not with MGMT promoter methylation. In conclusion, PIK3CA mutation is significantly associated with other key molecular events in colorectal cancer, and MGMT loss likely contributes to the development of PIK3CA G>A mutation. In addition, Pyrosequencing is useful in detecting PIK3CA mutation in archival paraffin tumor tissue. PIK3CA mutational data further emphasize heterogeneity of colorectal cancer at the molecular level. PMID:18516290

  2. Novel mouse model recapitulates genome and transcriptome alterations in human colorectal carcinomas.

    PubMed

    McNeil, Nicole E; Padilla-Nash, Hesed M; Buishand, Floryne O; Hue, Yue; Ried, Thomas

    2017-03-01

    Human colorectal carcinomas are defined by a nonrandom distribution of genomic imbalances that are characteristic for this disease. Often, these imbalances affect entire chromosomes. Understanding the role of these aneuploidies for carcinogenesis is of utmost importance. Currently, established transgenic mice do not recapitulate the pathognonomic genome aberration profile of human colorectal carcinomas. We have developed a novel model based on the spontaneous transformation of murine colon epithelial cells. During this process, cells progress through stages of pre-immortalization, immortalization and, finally, transformation, and result in tumors when injected into immunocompromised mice. We analyzed our model for genome and transcriptome alterations using ArrayCGH, spectral karyotyping (SKY), and array based gene expression profiling. ArrayCGH revealed a recurrent pattern of genomic imbalances. These results were confirmed by SKY. Comparing these imbalances with orthologous maps of human chromosomes revealed a remarkable overlap. We observed focal deletions of the tumor suppressor genes Trp53 and Cdkn2a/p16. High-level focal genomic amplification included the locus harboring the oncogene Mdm2, which was confirmed by FISH in the form of double minute chromosomes. Array-based global gene expression revealed distinct differences between the sequential steps of spontaneous transformation. Gene expression changes showed significant similarities with human colorectal carcinomas. Pathways most prominently affected included genes involved in chromosomal instability and in epithelial to mesenchymal transition. Our novel mouse model therefore recapitulates the most prominent genome and transcriptome alterations in human colorectal cancer, and might serve as a valuable tool for understanding the dynamic process of tumorigenesis, and for preclinical drug testing. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. The TP53 tumour suppressor gene in colorectal carcinomas. I. Genetic alterations on chromosome 17.

    PubMed Central

    Meling, G. I.; Lothe, R. A.; Børresen, A. L.; Graue, C.; Hauge, S.; Clausen, O. P.; Rognum, T. O.

    1993-01-01

    In 231 colorectal carcinomas, allele variation at four restriction fragments length polymorphisms (RFLP) loci on chromosome 17 have been studied by Southern analysis. Heterozygous loss of the TP53 gene was found in 68% (129/189) of the carcinomas informative on both chromosome arms. In 41% (77/189) of the carcinomas the loss was found only on 17p. Two probes were used to detect alterations on 17p, pBHP53 and pYNZ22. When loss was demonstrated with pYNZ22, pBHP53 also always showed loss (n = 45), whereas when loss was demonstrated with pBHP53, only 45 of 54 (83%) showed loss with pYNZ22. Loss on 17q was found in 34% (64/189) of the carcinomas, and 6% (12/189) had loss on this chromosome arm, only. Loss on 17q was significantly associated with loss on 17p (P < 0.01). These data confirm that the TP53 gene is the target of loss on chromosome arm 17p in colorectal carcinomas, and demonstrate that loss of the TP53 gene is most frequently part of limited, subchromosomal loss. Furthermore, the results do not suggest any additional tumour suppressor gene(s) on chromosome 17 involved in colorectal carcinogenesis. Images Figure 2 PMID:8094008

  4. Endocannabinoid and ceramide levels are altered in patients with colorectal cancer.

    PubMed

    Chen, Ling; Chen, Huixia; Li, Yanting; Li, Lei; Qiu, Yan; Ren, Jie

    2015-07-01

    Endocannabinoids and ceramides have demonstrated growth inhibition, cell death induction and pro-apoptotic activity in cancer research. In the present study, we describe the profiles of two major endocannabinoids, ceramides, free fatty acids and relevant metabolic enzymes in 47 pairs of human colorectal cancer tissues and adjacent non-tumor tissues. Among them, anandamide (AEA) and its metabolite, arachidonic acid (AA), were markedly upregulated in cancer tissues particularly in those with lymphatic metastasis. The levels of C16 and C24 ceramides were significantly elevated in the colorectal tumor tissues, while levels of C18 and C20 ceramides showed opposite trends. Levels of two enzymes participating in the biosynthesis and degradation of AEA, N-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D (NPLD) and fatty acid amide hydrolase (FAAH), together with the most abundant ceramide synthases (CerS1, CerS2, CerS5 and CerS6) in the colon were also determined. Quantitative-PCR analysis indicated that the mRNA levels of these enzymes were overexpressed in the tumor tissues. The activities of NPLD and FAAH were also upregulated. In addition, both gene and protein expression levels of cannabinoid receptor 1 (CB1) were elevated but not of CB2. Elevation of AEA and alteration of ceramides (C16, C24, C18, C20) may qualify as potential endogenous biomarkers and novel drug targets for colorectal cancer.

  5. Stage-dependent alterations of the serum cytokine pattern in colorectal carcinoma

    PubMed Central

    Kantola, T; Klintrup, K; Väyrynen, J P; Vornanen, J; Bloigu, R; Karhu, T; Herzig, K-H; Näpänkangas, J; Mäkelä, J; Karttunen, T J; Tuomisto, A; Mäkinen, M J

    2012-01-01

    Background: Inflammation contributes to the pathogenesis of colorectal cancer (CRC), and cytokine levels are altered during colorectal carcinogenesis. Methods: The serum levels of 13 cytokines and their relation to clinical and pathological parameters, and systemic inflammatory response (mGPS, CRP and neutrophil–lymphocyte ratio), were analysed from a prospective series of 148 CRC patients and 86 healthy age- and sex-matched controls. Results: CRC patients had higher serum platelet-derived growth factor, interleukin (IL)-6, IL-7, and IL-8 levels and lower monocyte chemotactic protein-1 (MCP-1) levels than the controls. A logistic regression model for discriminating the patients from the controls – including the five most predictive cytokines (high IL-8, high IL-6, low MCP-1, low IL-1ra, and low IP-10) – yielded an area under curve value of 0.890 in receiver operating characteristics analysis. Serum cytokines showed distinct correlation with other markers of systemic inflammatory response, and advanced CRCs were associated with higher levels of IL-8, IL-1ra, and IL-6. A metastasised disease was accompanied by an orientation towards Th2 cytokine milieu. Conclusion: CRC is associated with extensive alterations in serum cytokine environment, highlighting the importance of studying relative cytokine level alterations. Serum cytokine profile shows promise in separating CRC patients from healthy controls but its clinical value is yet to be confirmed. PMID:23059742

  6. Patterns of PIK3CA alterations in familial colorectal and endometrial carcinoma.

    PubMed

    Ollikainen, Miina; Gylling, Annette; Puputti, Marjut; Nupponen, Nina N; Abdel-Rahman, Wael M; Butzow, Ralf; Peltomäki, Päivi

    2007-08-15

    While the phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway is known to be activated in multiple sporadic cancers, the role of this pathway in familial tumors is mostly unknown. We searched for alterations in the catalytic domain of PI3K (PIK3CA), PTEN and KRAS, all of which may contribute to PI3K/AKT pathway activation, in a total of 160-familial colorectal (CRC) and endometrial carcinomas (EC), stratified by the presence vs. absence of germline mutations in DNA mismatch repair (MMR) genes. PIK3CA alterations (consisting of point mutations or low-level amplification, which were mutually exclusive with 1 exception) occurred in 10/70 (14%) of CRCs and 19/90 (21%) of ECs. Within ECs, amplification was significantly associated with the subgroup lacking germline mutations in MMR genes (familial site-specific endometrial cancer) (p = 0.015). Decreased or lost PTEN expression was characteristic of endometrial tumourigenesis (51/81, 63%, in EC compared with 24/62, 39%, in CRC, p = 0.004) and KRAS mutations of colorectal tumourigenesis (19/70, 27% in CRC vs. 9/89, 10%, in EC, p = 0.006) regardless of the MMR gene mutation status. PIK3CA alterations frequently coexisted with PTEN or KRAS changes. Combined with published studies on sporadic tumors, our data broaden the understanding of the role for PI3K pathway genes in human tumorigenesis.

  7. Genetic alterations and oxidative metabolism in sporadic colorectal tumors from a Spanish community.

    PubMed

    Oliva, M R; Ripoll, F; Muñiz, P; Iradi, A; Trullenque, R; Valls, V; Drehmer, E; Sáez, G T

    1997-04-01

    Deletions of loci on chromosomes 5q, 17p, 18q, and 22q, together with the incidence of p53 mutations and amplification of the double minute-2 gene were investigated in the sporadic colorectal tumors of 44 patients from a Spanish community. Chromosome deletions were analyzed by means of loss of heterozygosity analysis using a restriction fragment length polymorphism assay. Allelic losses were also detected by polymerase chain reaction (PCR)-single-stranded conformation polymorphism (SSCP) analysis of a polymorphic site in intron 2 of the p53 gene. The percentages of genetic deletions on the screened chromosomes were 39.3% (5q), 58.3% (17p), 40.9% (18q), and 40% (22q). Mutations in p53 exons 2-9 were examined by PCR-SSCP analysis and direct sequencing of the mutated region. Twenty of 44 tumor samples (45.45%) showed mutations at various exons except for exons 2, 3, and 9, the most frequent changes being G-->T transversion and C-->T transition. Because oxygen-free radicals play a role in the carcinogenesis process, we evaluated the oxidative status of the colorectal tumors. Antioxidant activities, lipid peroxidation, and DNA-damaged product concentrations in colon tumors and normal mucosa were compared. In tumor tissues, superoxide dismutase and catalase decreased fourfold and twofold, respectively, whereas glutathione peroxidase and reduced glutathione increased threefold. Malondialdehyde and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were twofold higher in colorectal tumors than in normal mucosa. Seven of 10 DNA tumor samples (70%) showing higher values of 8-OHdG also had genetic alterations at different chromosomal loci. In these samples, the p53 gene was deleted or mutated in 71.4% of cases. We concluded that the observed changes in the oxidative metabolism of the tumor cells and the consecutive increase in DNA damage may potentiate the genomic instability of different chromosomal regions, leading to further cell malignancy and tumor expansion.

  8. Altered selectivity in an Arabidopsis metal transporter.

    PubMed

    Rogers, E E; Eide, D J; Guerinot, M L

    2000-10-24

    Plants require metals for essential functions ranging from respiration to photosynthesis. These metals also contribute to the nutritional value of plants for both humans and livestock. Additionally, plants have the ability to accumulate nonessential metals such as cadmium and lead, and this ability could be harnessed to remove pollutant metals from the environment. Designing a transporter that specifically accumulates certain cations while excluding others has exciting applications in all of these areas. The Arabidopsis root membrane protein IRT1 is likely to be responsible for uptake of iron from the soil. Like other Fe(II) transporters identified to date, IRT1 transports a variety of other cations, including the essential metals zinc and manganese as well as the toxic metal cadmium. By heterologous expression in yeast, we show here that the replacement of a glutamic acid residue at position 103 in wild-type IRT1 with alanine increases the substrate specificity of the transporter by selectively eliminating its ability to transport zinc. Two other mutations, replacing the aspartic acid residues at either positions 100 or 136 with alanine, also increase IRT1 metal selectivity by eliminating transport of both iron and manganese. A number of other conserved residues in or near transmembrane domains appear to be essential for all transport function. Therefore, this study identifies at least some of the residues important for substrate selection and transport in a protein belonging to the ZIP gene family, a large transporter family found in a wide variety of organisms.

  9. RNF43 and ZNRF3 are commonly altered in serrated pathway colorectal tumorigenesis

    PubMed Central

    Bond, Catherine E.; McKeone, Diane M.; Kalimutho, Murugan; Bettington, Mark L.; Pearson, Sally-Ann; Dumenil, Troy D.; Wockner, Leesa F.; Burge, Matthew; Leggett, Barbara A.; Whitehall, Vicki L.J.

    2016-01-01

    Serrated pathway colorectal cancers (CRCs) are characterised by a BRAF mutation and half display microsatellite instability (MSI). The Wnt pathway is commonly upregulated in conventional CRC through APC mutation. By contrast, serrated cancers do not mutate APC. We investigated mutation of the ubiquitin ligases RNF43 and ZNRF3 as alternate mechanism of altering the Wnt signal in serrated colorectal neoplasia. RNF43 was mutated in 47/54(87%) BRAF mutant/MSI and 8/33(24%) BRAF mutant/microsatellite stable cancers compared to only 3/79(4%) BRAF wildtype cancers (p<0.0001). ZNRF3 was mutated in 16/54(30%) BRAF mutant/MSI and 5/33(15%) BRAF mutant/microsatellite stable compared to 0/27 BRAF wild type cancers (p=0.004). An RNF43 frameshift mutation (X659fs) occurred in 80% BRAF mutant/MSI cancers. This high rate was verified in a second series of 25/35(71%) BRAF mutant/MSI cancers. RNF43 and ZNRF3 had lower transcript expression in BRAF mutant compared to BRAF wildtype cancers and less cytoplasmic protein expression in BRAF mutant/MSI compared to other subtypes. Treatment with a porcupine inhibitor reduced RNF43/ZNRF3 mutant colony growth by 50% and synergised with a MEK inhibitor to dramatically reduce growth. This study suggests inactivation of RNF43 and ZNRF3 is important in serrated tumorigenesis and has identified a potential therapeutic strategy for this cancer subtype. PMID:27661107

  10. Concurrent genetic alterations in DNA polymerase proofreading and mismatch repair in human colorectal cancer

    PubMed Central

    Yoshida, Rintaro; Miyashita, Kaname; Inoue, Mayuko; Shimamoto, Akiyoshi; Yan, Zhao; Egashira, Akinori; Oki, Eiji; Kakeji, Yoshishiro; Oda, Shinya; Maehara, Yoshihiko

    2011-01-01

    Genomic sequences encoding the 3′ exonuclease (proofreading) domains of both replicative DNA polymerases, pol delta and pol epsilon, were explored simultaneously in human colorectal carcinomas including six established cell lines. Three unequivocal sequence alterations, including one previously reported, were found, and all these were considered as dysfunctional mutations in light of the local amino-acid sequences. In particular, the F367S mutation found in the POLE gene encoding the pol epsilon catalytic subunit, which includes the proofreading domain, is the first found in human diseases. Surprisingly, the tumours carrying these proofreading domain mutations were all defective in DNA mismatch repair (MMR). In addition to the two cell lines with acknowledged MMR gene mutations, the third tumour was also demonstrated to harbour a distinct mutation in MLH1, and indeed exhibited a microsatellite-unstable phenotype. These findings suggest that, in concert with MMR deficiency, defective polymerase proofreading may also contribute to the mutator phenotype observed in human colorectal cancer. Our observations may suggest previously unrecognised complexities in the molecular abnormalities underlying the mutator phenotype in human neoplasms. PMID:21157497

  11. Genetic alterations within the retinoblastoma locus in colorectal carcinomas. Relation to DNA ploidy pattern studied by flow cytometric analysis.

    PubMed Central

    Meling, G. I.; Lothe, R. A.; Børresen, A. L.; Hauge, S.; Graue, C.; Clausen, O. P.; Rognum, T. O.

    1991-01-01

    Alterations within the retinoblastoma (Rb) gene, as detected by the VNTR probe p68RS2.0, and flow cytometric DNA pattern have been analysed in 255 colorectal carcinomas. A total of 35.3% of the tumours had alterations within the Rb gene. Amplification of one allele was demonstrated in 29.5% of the tumours, and loss of heterozygosity was found in 11.5%. No association was found between amplification within the Rb gene and clinicopathological characteristics of the patients. The high frequency of alterations demonstrated within the Rb gene, suggests that this gene is involved in colorectal carcinogenesis with amplification as by far the most abundant genetic alteration. This may imply that the Rb gene has an oncogene-like function in colorectal carcinomas, rather than acting as a tumour suppressor gene. Sixty-three per cent of the carcinomas were DNA aneuploid, and a significant association was demonstrated between amplification within the Rb gene and DNA aneuploidy (P less than 0.01). Two other chromosome loci were analysed, on chromosome 1p (probe pYNZ2) and on chromosome 2p (probe pYNH24), respectively. On chromosome 1p, heterozygous loss was found in 22.2% of the tumours, indicating an involvement of this chromosome in a subset of colorectal carcinomas. Images Figure 1 PMID:1911187

  12. Molecular Characterization of Somatic Alterations in Dukes’ B and C Colorectal Cancers by Targeted Sequencing

    PubMed Central

    Abdul, Shafina-Nadiawati; Ab Mutalib, Nurul-Syakima; Sean, Khor S.; Syafruddin, Saiful E.; Ishak, Muhiddin; Sagap, Ismail; Mazlan, Luqman; Rose, Isa M.; Abu, Nadiah; Mokhtar, Norfilza M.; Jamal, Rahman

    2017-01-01

    Despite global progress in research, improved screening and refined treatment strategies, colorectal cancer (CRC) remains as the third most common malignancy. As each type of cancer is different and exhibits unique alteration patterns, identifying and characterizing gene alterations in CRC that may serve as biomarkers might help to improve diagnosis, prognosis and predict potential response to therapy. With the emergence of next generation sequencing technologies (NGS), it is now possible to extensively and rapidly identify the gene profile of individual tumors. In this study, we aimed to identify actionable somatic alterations in Dukes’ B and C in CRC via NGS. Targeted sequencing of 409 cancer-related genes using the Ion AmpliseqTM Comprehensive Cancer Panel was performed on genomic DNA obtained from paired fresh frozen tissues, cancer and normal, of Dukes’ B (n = 10) and Dukes’ C (n = 9) CRC. The sequencing results were analyzed using Torrent Suite, annotated using ANNOVAR and validated using Sanger sequencing. A total of 141 somatic non-synonymous sequence variations were identified in 86 genes. Among these, 64 variants (45%) were predicted to be deleterious, 38 variants (27%) possibly deleterious while the other 39 variants (28%) have low or neutral protein impact. Seventeen genes have alterations with frequencies of ≥10% in the patient cohort and with 14 overlapped genes in both Dukes’ B and C. The adenomatous polyposis coli gene (APC) was the most frequently altered gene in both groups (n = 6 in Dukes’ B and C). In addition, TP53 was more frequently altered in Dukes’ C (n = 7) compared to Dukes’ B (n = 4). Ten variants in APC, namely p.R283∗, p.N778fs, p.R805∗, p.Y935fs, p.E941fs, p.E1057∗, p.I1401fs, p.Q1378∗, p.E1379∗, and p.A1485fs were predicted to be driver variants. APC remains as the most frequently altered gene in the intermediate stages of CRC. Wnt signaling pathway is the major affected pathway followed by P53, RAS, TGF

  13. Altered colorectal afferent function associated with TNBS-induced visceral hypersensitivity in mice.

    PubMed

    Feng, Bin; La, Jun-Ho; Tanaka, Takahiro; Schwartz, Erica S; McMurray, Timothy P; Gebhart, G F

    2012-10-01

    Inflammation of the distal bowel is often associated with abdominal pain and hypersensitivity, but whether and which colorectal afferents contribute to the hypersensitivity is unknown. Using a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, we investigated colorectal hypersensitivity following intracolonic TNBS and associated changes in colorectum and afferent functions. C57BL/6 mice were treated intracolonically with TNBS or saline. Visceromotor responses to colorectal distension (15-60 mmHg) were recorded over 8 wk in TNBS- and saline-treated (control) mice. In other mice treated with TNBS or saline, colorectal inflammation was assessed by myeloperoxidase assay and immunohistological staining. In vitro single-fiber recordings were conducted on both TNBS and saline-treated mice to assess colorectal afferent function. Mice exhibited significant colorectal hypersensitivity through day 14 after TNBS treatment that resolved by day 28 with no resensitization through day 56. TNBS induced a neutrophil- and macrophage-based colorectal inflammation as well as loss of nerve fibers, all of which resolved by days 14-28. Single-fiber recordings revealed a net increase in afferent drive from stretch-sensitive colorectal afferents at day 14 post-TNBS and reduced proportions of mechanically insensitive afferents (MIAs) at days 14-28. Intracolonic TNBS-induced colorectal inflammation was associated with the development and recovery of hypersensitivity in mice, which correlated with a transient increase and recovery of sensitization of stretch-sensitive colorectal afferents and MIAs. These results indicate that the development and maintenance of colorectal hypersensitivity following inflammation are mediated by peripheral drive from stretch-sensitive colorectal afferents and a potential contribution from MIAs.

  14. Norepinephrine transporter heterozygous knockout mice exhibit altered transport and behavior.

    PubMed

    Fentress, H M; Klar, R; Krueger, J J; Sabb, T; Redmon, S N; Wallace, N M; Shirey-Rice, J K; Hahn, M K

    2013-11-01

    The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET(+/-) ), demonstrating that they display an approximately 50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET(+/-) mouse establishes an activated state of existing surface NET proteins. The NET(+/-) mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris water maze. These data suggest that recovery of near basal activity in NET(+/-) mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET(+/-) mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders.

  15. Norepinephrine Transporter Heterozygous Knockout Mice Exhibit Altered Transport and Behavior

    PubMed Central

    Fentress, HM; Klar, R; Krueger, JK; Sabb, T; Redmon, SN; Wallace, NM; Shirey-Rice, JK; Hahn, MK

    2013-01-01

    The norepinephrine (NE) transporter (NET) regulates synaptic NE availability for noradrenergic signaling in the brain and sympathetic nervous system. Although genetic variation leading to a loss of NET expression has been implicated in psychiatric and cardiovascular disorders, complete NET deficiency has not been found in people, limiting the utility of NET knockout mice as a model for genetically-driven NET dysfunction. Here, we investigate NET expression in NET heterozygous knockout male mice (NET+/−), demonstrating that they display an ~50% reduction in NET protein levels. Surprisingly, these mice display no significant deficit in NET activity, assessed in hippocampal and cortical synaptosomes. We found that this compensation in NET activity was due to enhanced activity of surface-resident transporters, as opposed to surface recruitment of NET protein or compensation through other transport mechanisms, including serotonin, dopamine or organic cation transporters. We hypothesize that loss of NET protein in the NET+/− mouse establishes an activated state of existing, surface NET proteins. NET+/− mice exhibit increased anxiety in the open field and light-dark box and display deficits in reversal learning in the Morris Water Maze. These data suggest recovery of near basal activity in NET+/− mice appears to be insufficient to limit anxiety responses or support cognitive performance that might involve noradrenergic neurotransmission. The NET+/− mice represent a unique model to study the loss and resultant compensatory changes in NET that may be relevant to behavior and physiology in human NET deficiency disorders. PMID:24102798

  16. Laminin gene LAMB4 is somatically mutated and expressionally altered in gastric and colorectal cancers.

    PubMed

    Choi, Mi Ryoung; An, Chang Hyeok; Yoo, Nam Jin; Lee, Sug Hyung

    2015-01-01

    Laminins are important in tumor invasion and metastasis as well as in maintenance of normal epithelial cell structures. However, mutation status of laminin chain-encoding genes remains unknown in cancers. Aim of this study was to explore whether laminin chain genes are mutated and expressionally altered in gastric (GC) and colorectal cancers (CRC). In a public database, we found that laminin chain genes LAMA1, LAMA3, LAMB1 and LAMB4 had mononucleotide repeats in the coding sequences that might be mutation targets in the cancers with microsatellite instability (MSI). We analyzed the genes in 88 GC and 139 CRC [high MSI (MSI-H) or stable MSI/low MSI (MSS/MSI-L)] by single strand conformation polymorphism analysis and DNA sequencing. In the present study, we found LAMB4 (11.8% of GC and 7.6% of CRC with MSI-H), LAMA3 (2.9% of GC and 2.5 of CRC with MSI-H), LAMA1 (5.9% of GC with MSI-H) and LAMB1 frameshift mutations (1.3% of CRC with MSI-H). These mutations were not found in MSS/MSI-L (0/114). We also analyzed LAMB4 expression in GC and CRC by immunohistochemistry. Loss of LAMB4 expression was identified in 17-32% of the GC and CRC. Of note, the loss expression was more common in the cancers with LAMB4 mutation or those with MSI-H. Our data show that frameshift mutations of LAMA1, LAMA3, LAMB1 and LAMB4, and loss of LAMB4 may be features of GC and CRC with MSI-H.

  17. Transportation: a vehicle or roadblock to cancer care for VA patients with colorectal cancer?

    PubMed

    Zullig, Leah L; Jackson, George L; Provenzale, Dawn; Griffin, Joan M; Phelan, Sean; van Ryn, Michelle

    2012-03-01

    Patients must have transportation to the treatment site before they can access appropriate cancer care. This article describes factors associated with patients experiencing transportation-related barriers to accessing cancer care. The Cancer Care Assessment & Responsive Evaluation Studies (C-CARES) questionnaire was mailed to Veterans Affairs (VA) patients with colorectal cancer (CRC) during the fall of 2009. Eligible patients were diagnosed at any VA facility in 2008, they were men, and alive at the time of the mailing. A total of 1409 surveys were returned (approximately 67% response rate). To assess transportation barriers, patients were asked how often it was difficult to get transportation to or from treatment. Symptoms were assessed using validated Patient-Reported Outcomes Measurement Information System (PROMIS) scales for fatigue, pain, and depression. Multivariate logistic regression was used to examine determinants of transportation barriers. A minority of respondents (19%) reported transportation barriers. Patients experiencing pain (OR, 1.04; 95% CI, 1.02-1.06) had greater odds of transportation barriers than patients without this symptom. Patients who reported no primary social support (OR, 6.13; 95% CI, 3.10-12.14) or nonspousal support (OR, 2.00; 95% CI, 1.40-2.87) were more likely to experience transportation barriers than patients whose spouses provided social support. Patients with uncontrolled pain or less social support have greater odds of transportation barriers. The directional association between social support, symptoms, and transportation cannot be determined in this data. Inquiring about accessible transportation should become a routine part of cancer care, particularly for patients with known risk factors. Published by Elsevier Inc.

  18. FX enzyme and GDP-L-Fuc transporter expression in colorectal cancer.

    PubMed

    Villar-Portela, Susana; Muinelo-Romay, Laura; Cuevas, Elisa; Gil-Martín, Emilio; Fernández-Briera, Almudena

    2013-08-01

    Fucosylation is regulated by fucosyltransferases, the guanosine diphosphate-L-fucose (GDP-L-Fuc) synthetic pathway, and the GDP-L-fucose transporter (GDP-L-Fuc Tr). We have reported previously an increased level of α(1,6)fucosyltransferase activity and expression in colorectal cancer (CRC). The present study aimed to analyse the expression profiles of the FX enzyme and GDP-L-Fuc Tr in a cohort of operated CRC patients to elucidate their role in α(1,6)fucosylation in this neoplasm. We assessed the immunohistochemical expression of FX and GDP-L-Fuc Tr in a series of tumour samples and healthy tissues from CRC specimens. FX expression was observed in 58 of 91 (63.7%) tumours and 23 of 28 (82.1%) corresponding healthy samples. GDP-L-Fuc Tr expression was detected in 86 of 102 (84.3%) colorectal tumours, and 13 of 27 (48.1%) healthy tissue specimens. The expression of GDP-L-Fuc Tr was statistically higher in tumours than in healthy tissues (P < 0.001). A correlation was found between FX and GDP-L-Fuc Tr expression in tumour samples (P = 0.003). GDP-L-Fuc Tr overexpression in the tumour tissue of CRC patients suggests that GDP-L-Fuc transport to the Golgi apparatus may be an important factor associated with increased α(1,6)fucosylation in CRC. © 2013 John Wiley & Sons Ltd.

  19. Alterations in the EGFR pathway coincide in colorectal cancer and impact on prognosis.

    PubMed

    Neumann, Jens; Wehweck, Laura; Maatz, Susanne; Engel, Jutta; Kirchner, Thomas; Jung, Andreas

    2013-10-01

    Alterations of the downstream effectors of the epidermal growth factor receptor (EGFR) are common events in colorectal cancer (CRC) carcinogenesis. Since EGFR serves as a target for therapy and some downstream effectors of EGFR have predictive and prognostic impact, reliable information on the frequency and concordance of alterations in the signaling pathway has become clinically significant. We, therefore, determined the frequency and coincidence of mutations in the EGFR pathway. We also analyzed the concordance of these alterations between primary tumor and distant metastases. Furthermore, we assessed their prognostic relevance for the development of metastasis. Mutations of KRAS exon 2, BRAF exons 11 and 15, AKT exon 3, and PIK3CA exons 9 and 20 were analyzed by pyrosequencing in 171 primary CRC samples as well as in 63 corresponding metastases. Furthermore, the expression of PTEN and EGFR was assessed by immunohistochemistry. Of the 171 tumors investigated, 60.2 % showed mutations in one or more genes of pathways downstream of EGFR. KRAS exon 2 and BRAF exon 15 mutations were detected in 40.9 and 11.1 % of cases, respectively, and were mutually exclusive. Mutations in exons 9 and 20 of the PIK3CA gene (18.7 %) largely overlapped with exon 2 KRAS mutations (16 of 32 cases; 50.0 %) and, to a lesser extent, with exon 15 mutations of BRAF (2 of 32 cases; 6.3 %). Only one case had simultaneous mutations of AKT exon 3 (0.6 %) and BRAF exon 15. Mutation analysis for KRAS exon 2, BRAF exon 15, PIK3CA exon 20, and AKT exon 3 in primary tumors and in their corresponding metastases revealed 100 % concordance. In one case, a PIK3CA exon 9 mutation in the primary tumor could not be detected in the matched distant metastases (κ = 0.9). Three different scores were applied for the evaluation of EGFR immunohistochemistry, and the range of positive cases varied between 8.8 and 52.6 %. Loss of PTEN expression was detected in 38.6 %. Although the expression of both

  20. Celecoxib pre-treatment in human colorectal adenocarcinoma patients is associated with gene expression alterations suggestive of diminished cellular proliferation.

    PubMed

    Auman, James Todd; Church, Robert; Lee, Soo-Youn; Watson, Mark A; Fleshman, James W; Mcleod, Howard L

    2008-08-01

    Cancer cells treated with the cyclooxygenase-2 inhibitor celecoxib show growth inhibition and induced apoptosis. This study was conducted to determine if the same processes are relevant to celecoxib's effects on human colorectal adenocarcinomas treated in vivo. A cohort of 23 patients with primary colorectal adenocarcinomas was randomised to receive a 7-d course of celecoxib (400mg b.i.d.) or no drug prior to surgical resection. Gene expression profiling was performed on resected adenocarcinomas from the cohort of patients. Using fold change (>1.5) and p-value (<0.05) cut-offs, 190 genes were differentially expressed between adenocarcinomas from patients receiving celecoxib and those that did not. The celecoxib pre-treated samples showed decreased expression levels in multiple genes involved in cellular lipid and glutathione metabolism; changes associated with diminished cellular proliferation. Celecoxib pre-treatment for 7 d in vivo is associated with alterations in colorectal adenocarcinoma gene expression which are suggestive of diminished cellular proliferation.

  1. Celecoxib pre-treatment in human colorectal adenocarcinoma patients is associated with gene expression alterations suggestive of diminished cellular proliferation

    PubMed Central

    Auman, James Todd; Church, Robert; Lee, Soo-Youn; Watson, Mark A.; Fleshman, James W.; Mcleod, Howard L.

    2008-01-01

    Cancer cells treated with the cyclooxygenase-2 inhibitor celecoxib show growth inhibition and induced apoptosis. This study was conducted to determine if the same processes are relevant to celecoxib’s effects on human colorectal adenocarcinomas treated in vivo. A cohort of 23 patients with primary colorectal adenocarcinomas was randomized to receive a 7-day course of celecoxib (400 mg b.i.d.) or no drug prior to surgical resection. Gene expression profiling was performed on resected adenocarcinomas from the cohort of patients. Using fold change (>1.5) and p-value (<0.05) cut-offs, 190 genes were differentially expressed between adenocarcinomas from patients receiving celecoxib and those that did not. The celecoxib pre-treated samples showed decreased expression levels in multiple genes involved in cellular lipid and glutathione metabolism; changes associated with diminished cellular proliferation. Celecoxib pre-treatment for 7 days in vivo is associated with alterations in colorectal adenocarcinoma gene expression which are suggestive of diminished cellular proliferation. PMID:18653328

  2. Fatty acids alter monolayer integrity, paracellular transport, and iron uptake and transport in Caco-2 cells.

    PubMed

    Droke, Elizabeth A; Briske-Anderson, Mary; Lukaski, Henry C

    2003-12-01

    The Caco-2 cell line was used as a model to determine if the type of fatty acid, unsaturated versus saturated, differentially altered the uptake and transport of iron in the human intestine and if the changes were the result of alterations in monolayer integrity and paracellular transport. Cells were cultured in either a lower-iron or normal-iron medium and incubated with a bovine serum albumin control, linoleate, oleate, palmatate, or stearate. Oleate, palmatate, and stearate enhanced (p < 0.05) iron uptake in cells grown in lower iron. The fatty acid effect on iron uptake by cells grown in normal iron was not as pronounced. Iron transport was not affected (p > 0.05) by an interaction between the type of medium (iron concentration) and the type of fatty acid. Iron transport was enhanced (p < 0.05) with palmatate and stearate. Various indicators of monolayer integrity and paracellular transport were also affected by the fatty acids, thus impacting iron uptake and transport. These results indicate that oleate, palmatate, and stearic can enhance iron uptake and transport; however, this enhancement may be the result of alterations in the integrity of the intestine.

  3. Uranium (VI) and Neptunium (V) Transport Fractured, Hydrothermally Altered Concrete

    SciTech Connect

    Matzen, S.L.; Beiriger, J.M.; Torretto, P.C.; Zhao, P.

    1999-11-04

    In a high level waste repository in which temperatures are elevated due to waste decay, concrete structures will be subjected to hydrothermal conditions that will alter their physical and chemical properties. Virtually no studies have examined the interaction of hydrothermally altered concrete with radionuclides. We present the results of experiments in which soluble and colloid-associated actinides, uranium (U) and neptunium (Np), were eluted into a fractured, hydrothermally altered concrete core. Although the fluid residence time in the fracture was estimated to be on the order of 1 minute, U and Np were below detection (10{sup -9}-10{sup -8} M) in the effluent from the core, for both soluble and colloid-associated species. Inorganic colloids and latex microspheres were similarly immobilized within the core. Post-test analysis of the core identified the immobilized U and Np at or near the fracture surface, with a spatial distribution similar to that of the latex microspheres. Because hydrothermal alteration followed fracturing, the growth of crystalline calcium silicate hydrate and clay mineral alteration products on, and possibly across the fracture, resulted in a highly reactive fracture that was effective at capturing both soluble and colloidal radionuclides. Comparison of results from batch experiments [1] with these experiments indicate that partitioning of U and Np to the solid phase, and equilibration of the incoming fluid with the concrete, occurs rapidly in the fractured system. Transport of U through the concrete may be solubility and/or sorption limited; transport of Np appears to be limited primarily by sorption.

  4. NDRG2 gene copy number is not altered in colorectal carcinoma

    PubMed Central

    Lorentzen, Anders; Mitchelmore, Cathy

    2017-01-01

    AIM To investigate if the down-regulation of N-myc Downstream Regulated Gene 2 (NDRG2) expression in colorectal carcinoma (CRC) is due to loss of the NDRG2 allele(s). METHODS The following were investigated in the human colorectal cancer cell lines DLD-1, LoVo and SW-480: NDRG2 mRNA expression levels using quantitative reverse transcription-polymerase chain reaction (qRT-PCR); interaction of the MYC gene-regulatory protein with the NDRG2 promoter using chromatin immunoprecipitation; and NDRG2 promoter methylation using bisulfite sequencing. Furthermore, we performed qPCR to analyse the copy numbers of NDRG2 and MYC genes in the above three cell lines, 8 normal colorectal tissue samples and 40 CRC tissue samples. RESULTS As expected, NDRG2 mRNA levels were low in the three colorectal cancer cell lines, compared to normal colon. Endogenous MYC protein interacted with the NDRG2 core promoter in all three cell lines. In addition, the NDRG2 promoter was heavily methylated in these cell lines, suggesting an epigenetic regulatory mechanism. Unaltered gene copy numbers of NDRG2 were observed in the three cell lines. In the colorectal tissues, one normal and three CRC samples showed partial or complete loss of one NDRG2 allele. In contrast, the MYC gene was amplified in one cell line and in more than 40% of the CRC cases. CONCLUSION Our study suggests that the reduction in NDRG2 expression observed in CRC is due to transcriptional repression by MYC and promoter methylation, and is not due to allelic loss. PMID:28246586

  5. Monocarboxylate transport inhibition potentiates the cytotoxic effect of 5-fluorouracil in colorectal cancer cells.

    PubMed

    Amorim, Ricardo; Pinheiro, Céline; Miranda-Gonçalves, Vera; Pereira, Helena; Moyer, Mary P; Preto, Ana; Baltazar, Fátima

    2015-08-28

    Cancer cells rely mostly on glycolysis to meet their energetic demands, producing large amounts of lactate that are extruded to the tumour microenvironment by monocarboxylate transporters (MCTs). The role of MCTs in the survival of colorectal cancer (CRC) cells is scarce and poorly understood. In this study, we aimed to better understand this issue and exploit these transporters as novel therapeutic targets alone or in combination with the CRC classical chemotherapeutic drug 5-Fluorouracil. For that purpose, we characterized the effects of MCT activity inhibition in normal and CRC derived cell lines and assessed the effect of MCT inhibition in combination with 5-FU. Here, we demonstrated that MCT inhibition using CHC (α-cyano-4-hydroxycinnamic acid), DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid) and quercetin decreased cell viability, disrupted the glycolytic phenotype, inhibited proliferation and enhanced cell death in CRC cells. These results were confirmed by specific inhibition of MCT1/4 by RNA interference. Notably, we showed that 5-FU cytotoxicity was potentiated by lactate transport inhibition in CRC cells, either by activity inhibition or expression silencing. These findings provide novel evidence for the pivotal role of MCTs in CRC maintenance and survival, as well as for the use of these transporters as potential new therapeutic targets in combination with CRC conventional therapy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Osmotic stress alters chromatin condensation and nucleocytoplasmic transport

    PubMed Central

    Finan, John D.; Leddy, Holly A.; Guilak, Farshid

    2011-01-01

    Osmotic stress is a potent regulator of biological function in many cell types, but its mechanism of action is only partially understood. In this study, we examined whether changes in extracellular osmolality can alter chromatin condensation and the rate of nucleocytoplasmic transport, as potential mechanisms by which osmotic stress can act. Transport of 10 kDa dextran was measured both within and between the nucleus and the cytoplasm using two different photobleaching methods. A mathematical model was developed to describe fluorescence recovery via nucleocytoplasmic transport. As osmolality increased, the diffusion coefficient of dextran decreased in the cytoplasm, but not the nucleus. Hyper-osmotic stress decreased nuclear size and increased nuclear lacunarity, indicating that while the nucleus was getting smaller, the pores and channels interdigitating the chromatin had expanded. The rate of nucleocytoplasmic transport was increased under hyper-osmotic stress but was insensitive to hypo-osmotic stress, consistent with the nonlinear osmotic properties of the nucleus. The mechanism of this osmotic sensitivity appears to be a change in the size and geometry of the nucleus, resulting in a shorter effective diffusion distance for the nucleus. These results may explain physical mechanisms by which osmotic stress can influence intracellular signaling pathways that rely on nucleocytoplasmic transport. PMID:21463604

  7. Continuous-time random walks that alter environmental transport properties.

    PubMed

    Angstmann, C; Henry, B I

    2011-12-01

    We consider continuous-time random walks (CTRWs) in which the walkers have a finite probability to alter the waiting-time and/or step-length transport properties of their environment, resulting in possibly transient anomalous diffusion. We refer to these CTRWs as transmogrifying continuous-time random walks (TCTRWs) to emphasize that they change the form of the transport properties of their environment, and in a possibly strange way. The particular case in which the CTRW waiting-time density has a finite probability to be permanently altered at a given site, following a visitation by a walker, is considered in detail. Master equations for the probability density function of transmogrifying random walkers are derived, and results are compared with Monte Carlo simulations. An interesting finding is that TCTRWs can generate transient subdiffusion or transient superdiffusion without invoking truncated or tempered power law densities for either the waiting times or the step lengths. The transient subdiffusion or transient superdiffusion arises in TCTRWs with Gaussian step-length densities and exponential waiting-time densities when the altered average waiting time is greater than or less than, respectively, the original average waiting time.

  8. Estrone Sulfate Transport and Steroid Sulfatase Activity in Colorectal Cancer: Implications for Hormone Replacement Therapy

    PubMed Central

    Gilligan, Lorna C.; Gondal, Ali; Tang, Vivien; Hussain, Maryam T.; Arvaniti, Anastasia; Hewitt, Anne-Marie; Foster, Paul A.

    2017-01-01

    Hormone replacement therapy (HRT) affects the incidence and potential progression of colorectal cancer (CRC). As HRT primarily consists of estrone sulfate (E1S), understanding whether this conjugated estrogen is transported and metabolized in CRC will define its potential effect in this malignancy. Here, we show that a panel of CRC cell lines (Colo205, Caco2, HCT116, HT-29) have steroid sulfatase (STS) activity, and thus can hydrolyze E1S. STS activity is significantly higher in CRC cell lysate, suggesting the importance of E1S transport in intracellular STS substrate availability. As E1S transport is regulated by the expression pattern of certain solute carrier organic anion transporter polypeptides, we show that in CRC OATP4A1 is the most abundantly expressed transporter. All four CRC cell lines rapidly transported E1S into cells, with this effect significantly inhibited by the competitive OATP inhibitor BSP. Transient knockdown of OATP4A1 significantly disrupted E1S uptake. Examination of estrogen receptor status showed ERα was present in Colo205 and Caco2 cells. None of the cells expressed ERβ. Intriguingly, HCT116 and HT29 cells strongly expressed the G protein coupled estrogen receptor (GPER), and that stimulation of this receptor with estradiol (E2) and G1, a GPER agonist, significantly (p < 0.01) increased STS activity. Furthermore, tamoxifen and fulvestrant, known GPER agonist, also increased CRC STS activity, with this effect inhibited by the GPER antagonist G15. These results suggest that CRC can take up and hydrolyze E1S, and that subsequent GPER stimulation increases STS activity in a potentially novel positive feedback loop. As elevated STS expression is associated with poor prognosis in CRC, these results suggest HRT, tamoxifen and fulvestrant may negatively impact CRC patient outcomes. PMID:28326039

  9. Altered Reward Circuitry in the Norepinephrine Transporter Knockout Mouse

    PubMed Central

    Hall, F. Scott; Uhl, George R.; Bearer, Elaine L.; Jacobs, Russell E.

    2013-01-01

    Synaptic levels of the monoamine neurotransmitters dopamine, serotonin, and norepinephrine are modulated by their respective plasma membrane transporters, albeit with a few exceptions. Monoamine transporters remove monoamines from the synaptic cleft and thus influence the degree and duration of signaling. Abnormal concentrations of these neuronal transmitters are implicated in a number of neurological and psychiatric disorders, including addiction, depression, and attention deficit/hyperactivity disorder. This work concentrates on the norepinephrine transporter (NET), using a battery of in vivo magnetic resonance imaging techniques and histological correlates to probe the effects of genetic deletion of the norepinephrine transporter on brain metabolism, anatomy and functional connectivity. MRS recorded in the striatum of NET knockout mice indicated a lower concentration of NAA that correlates with histological observations of subtle dysmorphisms in the striatum and internal capsule. As with DAT and SERT knockout mice, we detected minimal structural alterations in NET knockout mice by tensor-based morphometric analysis. In contrast, longitudinal imaging after stereotaxic prefrontal cortical injection of manganese, an established neuronal circuitry tracer, revealed that the reward circuit in the NET knockout mouse is biased toward anterior portions of the brain. This is similar to previous results observed for the dopamine transporter (DAT) knockout mouse, but dissimilar from work with serotonin transporter (SERT) knockout mice where Mn2+ tracings extended to more posterior structures than in wildtype animals. These observations correlate with behavioral studies indicating that SERT knockout mice display anxiety-like phenotypes, while NET knockouts and to a lesser extent DAT knockout mice display antidepressant-like phenotypic features. Thus, the mainly anterior activity detected with manganese-enhanced MRI in the DAT and NET knockout mice is likely indicative of

  10. Osmotic stress alters chromatin condensation and nucleocytoplasmic transport

    SciTech Connect

    Finan, John D.; Leddy, Holly A.; Guilak, Farshid

    2011-05-06

    Highlights: {yields} The rate of nucleocytoplasmic transport increases under hyper-osmotic stress. {yields} The mechanism is a change in nuclear geometry, not a change in permeability of the nuclear envelope. {yields} Intracytoplasmic but not intranuclear diffusion is sensitive to osmotic stress. {yields} Pores in the chromatin of the nucleus enlarge under hyper-osmotic stress. -- Abstract: Osmotic stress is a potent regulator of biological function in many cell types, but its mechanism of action is only partially understood. In this study, we examined whether changes in extracellular osmolality can alter chromatin condensation and the rate of nucleocytoplasmic transport, as potential mechanisms by which osmotic stress can act. Transport of 10 kDa dextran was measured both within and between the nucleus and the cytoplasm using two different photobleaching methods. A mathematical model was developed to describe fluorescence recovery via nucleocytoplasmic transport. As osmolality increased, the diffusion coefficient of dextran decreased in the cytoplasm, but not the nucleus. Hyper-osmotic stress decreased nuclear size and increased nuclear lacunarity, indicating that while the nucleus was getting smaller, the pores and channels interdigitating the chromatin had expanded. The rate of nucleocytoplasmic transport was increased under hyper-osmotic stress but was insensitive to hypo-osmotic stress, consistent with the nonlinear osmotic properties of the nucleus. The mechanism of this osmotic sensitivity appears to be a change in the size and geometry of the nucleus, resulting in a shorter effective diffusion distance for the nucleus. These results may explain physical mechanisms by which osmotic stress can influence intracellular signaling pathways that rely on nucleocytoplasmic transport.

  11. Association of HPV with genetic and epigenetic alterations in colorectal adenocarcinoma from Indian population.

    PubMed

    Laskar, Ruhina S; Talukdar, Fazlur R; Choudhury, Javed H; Singh, Seram Anil; Kundu, Sharbadeb; Dhar, Bishal; Mondal, Rosy; Ghosh, Sankar Kumar

    2015-06-01

    Several studies from developing countries have shown human papillomavirus to be associated with colorectal cancers, but the molecular characteristics of such cancers are poorly known. We studied the various genetic variations like microsatellite instability (MSI), oncogenic mutations and epigenetic deregulations like CpG island methylation in HPV associated and nonassociated colorectal cancer patients from Indian population. HPV DNA was detected by PCR using My09/My11 and Gp5+/Gp6+ consensus primers and typed using HPV16 and HPV18 specific primers. MSI was detected using BAT 25 and BAT 26 markers, and mutation of KRAS, TP53 and BRAF V600E were detected by direct sequencing. Methyl specific polymerase chain reaction (MSP) was used to determine promoter methylation of the classical CIMP panel markers (P16, hMLH1, MINT1, MINT2 and MINT31) and other tumour-related genes (DAPK, RASSF1, BRCA1 and GSTP1). HPV DNA was detected in 34/93 (36.5 %) colorectal tumour tissues, HPV 18 being the predominant high-risk type. MSI was detected in 7.5 % cases; KRAS codon 12, 13, BRAF V600E and TP53 mutations were detected in 36.5, 3.2 and 37.6 % of the cases, respectively. CIMP-high was observed in 44.08 % cases. HPV presence was not associated with age, stage or grade of tumours, MSI or mutations in KRAS, TP53 or BRAF genes. Higher methylation frequencies of all genes/loci under study except RASSF1, as well as significantly higher CIMP-high characteristics were observed in HPV positive tumours as compared to negative cases. HPV in association with genetic and epigenetic features might be a potent risk factor for colorectal cancer in Indian population.

  12. Characterization of acetate transport in colorectal cancer cells and potential therapeutic implications

    PubMed Central

    Ferro, Suellen; Azevedo-Silva, João; Casal, Margarida; Côrte-Real, Manuela; Baltazar, Fatima; Preto, Ana

    2016-01-01

    Acetate, together with other short chain fatty acids has been implicated in colorectal cancer (CRC) prevention/therapy. Acetate was shown to induce apoptosis in CRC cells. The precise mechanism underlying acetate transport across CRC cells membrane, that may be implicated in its selectivity towards CRC cells, is not fully understood and was addressed here. We also assessed the effect of acetate in CRC glycolytic metabolism and explored its use in combination with the glycolytic inhibitor 3-bromopyruvate (3BP). We provide evidence that acetate enters CRC cells by the secondary active transporters MCT1 and/or MCT2 and SMCT1 as well as by facilitated diffusion via aquaporins. CRC cell exposure to acetate upregulates the expression of MCT1, MCT4 and CD147, while promoting MCT1 plasma membrane localization. We also observed that acetate increases CRC cell glycolytic phenotype and that acetate-induced apoptosis and anti-proliferative effect was potentiated by 3BP. Our data suggest that acetate selectivity towards CRC cells might be explained by the fact that aquaporins and MCTs are found overexpressed in CRC clinical cases. Our work highlights the importance that acetate transport regulation has in the use of drugs such as 3BP as a new therapeutic strategy for CRC. PMID:28874966

  13. EB1 protein alteration characterizes sporadic but not ulcerative colitis associated colorectal cancer

    PubMed Central

    Karstens, Karl F.; Hò, Gia G.; Hartwig, Sonja; Strohkamp, Sarah; Schillo, Katharina; Thorns, Christoph; Oberländer, Martina; Kalies, Kathrin; Lehr, Stefan; Habermann, Jens K.

    2017-01-01

    Background While carcinogenesis in Sporadic Colorectal Cancer (SCC) has been thoroughly studied, less is known about Ulcerative Colitis associated Colorectal Cancer (UCC). This study aimed to identify and validate differentially expressed proteins between clinical samples of SCC and UCC to elucidate new insights of UCC/SCC carcinogenesis and progression. Results Multiplex-fluorescence two-dimensional gel electrophoresis (2-D DIGE) and mass spectrometry identified 67 proteoforms representing 43 distinct proteins. After analysis by Ingenuity Pathway Analysis® (IPA), subsequent Western blot validation proofed the differential expression of Heat shock 27 kDA protein 1 (HSPB1) and Microtubule-associated protein R/EB family, member 1 (EB1) while the latter one showed also expression differences by immunohistochemistry. Materials and Methods Fresh frozen tissue of UCC (n = 10) matched with SCC (n = 10) was investigated. Proteins of cancerous intestinal mucosal cells were obtained by Laser Capture Microdissection (LCM) and compared by 2-D DIGE. Significant spots were identified by mass spectrometry. After IPA, three proteins [EB1, HSPB1, and Annexin 5 (ANXA5)] were chosen for further validation by Western blotting and tissue microarray-based immunohistochemistry. Conclusions This study identified significant differences in protein expression of colorectal carcinoma cells from UCC patients compared to patients with SCC. Particularly, EB1 was validated in an independent clinical cohort. PMID:28903393

  14. Copy number alterations of chromosomal regions enclosing protein tyrosine phosphatase receptor-like genes in colorectal cancer.

    PubMed

    Laczmanska, Izabela; Karpinski, Pawel; Kozlowska, Joanna; Bebenek, Marek; Ramsey, David; Sedziak, Tomasz; Ziolkowski, Piotr; Sasiadek, Maria M

    2014-12-01

    Protein tyrosine phosphatases that act in different cellular pathways are described most commonly as tumor suppressors, but also as oncogenes. Their role has previously been described in colorectal cancer, as well as in gastric, breast, thyroid, prostate, ovarian, pancreatic, glioma, liver, leukemia and many other cancers. In a previous study, we have described protein tyrosine phosphatase receptor type T, M, Z1 and Q genes (PTPRT, PTPRM, PTPRZ1 and PTPRQ) hypermethylated in sporadic colorectal cancer. Thus, in this study, we examined the relation of unbalanced chromosomal alterations within regions covering these four protein tyrosine phosphatase genes with this cancer. One hundred and two cancer tissues were molecularly characterized, including analysis of the BRAF and K-ras mutations and methylator phenotype. The analysis of chromosomal aberrations was performed using Comparative Genomic Hybridization. We observed amplification of three regions containing genes coding for PTPs, such as PTPRZ1 (7q31.3, amplified in 23.5% of cases), PTPRQ (12q21.2, amplified in 5.9% of cases), PTPRT (20q12, amplified in 29.4% of cases), along with deletions in the region of PTPRM (18p11.2, deleted in 21.6% of cases). These data may suggest that in sporadic colorectal cancer PTPRZ1, PTPRT, PTPRQ probably act as oncogenes, while PTPRM acts as a tumor suppressor gene. Our study also revealed that gains on chromosome 20q12 and losses on chromosome 18p11.2 are connected with the absence of the BRAF mutation and the conventional adenocarcinoma pathway. Copyright © 2014 Elsevier GmbH. All rights reserved.

  15. Altered Neurocircuitry in the Dopamine Transporter Knockout Mouse Brain

    PubMed Central

    Zhang, Xiaowei; Bearer, Elaine L.; Boulat, Benoit; Hall, F. Scott; Uhl, George R.; Jacobs, Russell E.

    2010-01-01

    The plasma membrane transporters for the monoamine neurotransmitters dopamine, serotonin, and norepinephrine modulate the dynamics of these monoamine neurotransmitters. Thus, activity of these transporters has significant consequences for monoamine activity throughout the brain and for a number of neurological and psychiatric disorders. Gene knockout (KO) mice that reduce or eliminate expression of each of these monoamine transporters have provided a wealth of new information about the function of these proteins at molecular, physiological and behavioral levels. In the present work we use the unique properties of magnetic resonance imaging (MRI) to probe the effects of altered dopaminergic dynamics on meso-scale neuronal circuitry and overall brain morphology, since changes at these levels of organization might help to account for some of the extensive pharmacological and behavioral differences observed in dopamine transporter (DAT) KO mice. Despite the smaller size of these animals, voxel-wise statistical comparison of high resolution structural MR images indicated little morphological change as a consequence of DAT KO. Likewise, proton magnetic resonance spectra recorded in the striatum indicated no significant changes in detectable metabolite concentrations between DAT KO and wild-type (WT) mice. In contrast, alterations in the circuitry from the prefrontal cortex to the mesocortical limbic system, an important brain component intimately tied to function of mesolimbic/mesocortical dopamine reward pathways, were revealed by manganese-enhanced MRI (MEMRI). Analysis of co-registered MEMRI images taken over the 26 hours after introduction of Mn2+ into the prefrontal cortex indicated that DAT KO mice have a truncated Mn2+ distribution within this circuitry with little accumulation beyond the thalamus or contralateral to the injection site. By contrast, WT littermates exhibit Mn2+ transport into more posterior midbrain nuclei and contralateral mesolimbic structures at

  16. Assessment of epigenetic alterations in early colorectal lesions containing BRAF mutations

    PubMed Central

    Nojima, Masanori; Harada, Taku; Maruyama, Reo; Ashida, Masami; Aoki, Hironori; Matsushita, Hiro-o; Yoshikawa, Kenjiro; Harada, Eiji; Tanaka, Yoshihito; Wakita, Shigenori; Niinuma, Takeshi; Kai, Masahiro; Eizuka, Makoto; Sugai, Tamotsu; Suzuki, Hiromu

    2016-01-01

    To clarify the molecular and clinicopathological characteristics of colorectal serrated lesions, we assessed the DNA methylation of cancer-associated genes in a cohort of BRAF-mutant precancerous lesions from 94 individuals. We then compared those results with the lesions' clinicopathological features, especially colorectal subsites. The lesions included hyperplastic polyps (n = 16), traditional serrated adenomas (TSAs) (n = 15), TSAs with sessile serrated adenomas (SSAs) (n = 6), SSAs (n = 49) and SSAs with dysplasia (n = 16). The prevalence of lesions exhibiting the CpG island methylator phenotype (CIMP) was lower in the sigmoid colon and rectum than in other bowel subsites, including the cecum, ascending, transverse and descending colon. In addition, several cancer-associated genes showed higher methylation levels within lesions in the proximal to sigmoid colon than in the sigmoid colon and rectum. These results indicate that the methylation status of lesions with BRAF mutation is strongly associated with their location, histological findings and neoplastic pathways. By contrast, no difference in aberrant DNA methylation was observed in normal-appearing background colonic mucosa along the bowel subsites, which may indicate the absence of an epigenetic field defect. PMID:27145369

  17. Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology.

    PubMed

    Andersen, Vibeke; Svenningsen, Katrine; Knudsen, Lina Almind; Hansen, Axel Kornerup; Holmskov, Uffe; Stensballe, Allan; Vogel, Ulla

    2015-11-07

    To evaluate ATP-binding cassette (ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer (CRC) development. Literature search was conducted on PubMed using combinations of the following terms: ABC transporters, ATP binding cassette transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohn's disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1/Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes in relation to colitis was suggested by the animal studies. The finding that colitis was preceded by altered gut bacterial composition suggests that deletion of Abcb1 leads to fundamental changes of host-microbiota interaction. Also, high fat diet increases the frequency and severity of colitis in specific pathogen-free Abcb1 KO mice. The Abcb1 KO mice might thus serve as a model in which diet/environmental factors and microbes may be controlled and investigated in relation to intestinal inflammation. Potential molecular mechanisms include defective transport of inflammatory mediators and/or phospholipid translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters and which may additionally affect ABC transporter function through nuclear receptors and transcriptional regulation. Another critical role of ABCB1 was suggested by the finding that ABCB1 expression

  18. Novel understanding of ABC transporters ABCB1/MDR/P-glycoprotein, ABCC2/MRP2, and ABCG2/BCRP in colorectal pathophysiology

    PubMed Central

    Andersen, Vibeke; Svenningsen, Katrine; Knudsen, Lina Almind; Hansen, Axel Kornerup; Holmskov, Uffe; Stensballe, Allan; Vogel, Ulla

    2015-01-01

    AIM: To evaluate ATP-binding cassette (ABC) transporters in colonic pathophysiology as they had recently been related to colorectal cancer (CRC) development. METHODS: Literature search was conducted on PubMed using combinations of the following terms: ABC transporters, ATP binding cassette transporter proteins, inflammatory bowel disease, ulcerative, colitis, Crohns disease, colorectal cancer, colitis, intestinal inflammation, intestinal carcinogenesis, ABCB1/P-glycoprotein (P-gp/CD243/MDR1), ABCC2/multidrug resistance protein 2 (MRP2) and ABCG2/breast cancer resistance protein (BCRP), Abcb1/Mdr1a, abcc2/Mrp2, abcg2/Bcrp, knock-out mice, tight junction, membrane lipid function. RESULTS: Recently, human studies reported that changes in the levels of ABC transporters were early events in the adenoma-carcinoma sequence leading to CRC. A link between ABCB1, high fat diet and gut microbes in relation to colitis was suggested by the animal studies. The finding that colitis was preceded by altered gut bacterial composition suggests that deletion of Abcb1 leads to fundamental changes of host-microbiota interaction. Also, high fat diet increases the frequency and severity of colitis in specific pathogen-free Abcb1 KO mice. The Abcb1 KO mice might thus serve as a model in which diet/environmental factors and microbes may be controlled and investigated in relation to intestinal inflammation. Potential molecular mechanisms include defective transport of inflammatory mediators and/or phospholipid translocation from one side to the other of the cell membrane lipid bilayer by ABC transporters affecting inflammatory response and/or function of tight junctions, phagocytosis and vesicle trafficking. Also, diet and microbes give rise to molecules which are potential substrates for the ABC transporters and which may additionally affect ABC transporter function through nuclear receptors and transcriptional regulation. Another critical role of ABCB1 was suggested by the finding that

  19. Decreased dietary fiber intake and structural alteration of gut microbiota in patients with advanced colorectal adenoma.

    PubMed

    Chen, Hui-Min; Yu, Ya-Nan; Wang, Ji-Lin; Lin, Yan-Wei; Kong, Xuan; Yang, Chang-Qing; Yang, Li; Liu, Zhan-Ju; Yuan, Yao-Zong; Liu, Fei; Wu, Jian-Xin; Zhong, Liang; Fang, Dian-Chun; Zou, Weiping; Fang, Jing-Yuan

    2013-05-01

    Accumulating evidence indicates that diet is one of the most important environmental factors involved in the progression from advanced colorectal adenoma (A-CRA) to colorectal cancer. We evaluated the possible effects of dietary fiber on the fecal microbiota of patients with A-CRA. Patients with a diagnosis of A-CRA by pathological examination were enrolled in the A-CRA group. Patients with no obvious abnormalities or histopathological changes were enrolled in the healthy control (HC) group. Dietary fiber intake was assessed in all patients. Short-chain fatty acids (SCFAs) in feces were detected by gas chromatography. The fecal microbiota community was analyzed by 454 pyrosequencing based on 16S ribosomal RNA. Lower dietary fiber patterns and consistently lower SCFA production were observed in the A-CRA group (n = 344). Principal component analysis showed distinct differences in the fecal microbiota communities of the 2 groups. Clostridium, Roseburia, and Eubacterium spp. were significantly less prevalent in the A-CRA group (n = 47) than in the HC group (n = 47), whereas Enterococcus and Streptococcus spp. were more prevalent in the A-CRA group (n = 47) (all P < 0.05). Butyrate and butyrate-producing bacteria were more prevalent in a subgroup of HC subjects with a high fiber intake than in those in both the low-fiber HC subgroup and the high-fiber A-CRA subgroup (all P < 0.05). A high-fiber dietary pattern and subsequent consistent production of SCFAs and healthy gut microbiota are associated with a reduced risk of A-CRA. This trial was registered at www.chictr.org as ChiCTR-TRC-00000123.

  20. Mutational analysis of genes coding for cell surface proteins in colorectal cancer cell lines reveal novel altered pathways, druggable mutations and mutated epitopes for targeted therapy

    PubMed Central

    Correa, Bruna R.; Bettoni, Fabiana; Koyama, Fernanda C.; Navarro, Fabio C.P.; Perez, Rodrigo O.; Mariadason, John; Sieber, Oliver M.; Strausberg, Robert L.; Simpson, Andrew J.G.; Jardim, Denis L.F.; Reis, Luiz Fernando L.; Parmigiani, Raphael B.; Galante, Pedro A.F.; Camargo, Anamaria A.

    2014-01-01

    We carried out a mutational analysis of 3,594 genes coding for cell surface proteins (Surfaceome) in 23 colorectal cancer cell lines, searching for new altered pathways, druggable mutations and mutated epitopes for targeted therapy in colorectal cancer. A total of 3,944 somatic non-synonymous substitutions and 595 InDels, occurring in 2,061 (57%) Surfaceome genes were catalogued. We identified 48 genes not previously described as mutated in colorectal tumors in the TCGA database, including genes that are mutated and expressed in >10% of the cell lines (SEMA4C, FGFRL1, PKD1, FAM38A, WDR81, TMEM136, SLC36A1, SLC26A6, IGFLR1). Analysis of these genes uncovered important roles for FGF and SEMA4 signaling in colorectal cancer with possible therapeutic implications. We also found that cell lines express on average 11 druggable mutations, including frequent mutations (>20%) in the receptor tyrosine kinases AXL and EPHA2, which have not been previously considered as potential targets for colorectal cancer. Finally, we identified 82 cell surface mutated epitopes, however expression of only 30% of these epitopes was detected in our cell lines. Notwithstanding, 92% of these epitopes were expressed in cell lines with the mutator phenotype, opening new venues for the use of “general” immune checkpoint drugs in this subset of patients. PMID:25193853

  1. Measuring the combinatorial expression of solute transporters and metalloproteinases transcripts in colorectal cancer

    PubMed Central

    Kerr, Caroline A; Dunne, Robert; Hines, Barney M; Zucker, Michelle; Cosgrove, Leah; Ruszkiewicz, Andrew; Lockett, Trevor; Head, Richard

    2009-01-01

    Background It was hypothesised that colorectal cancer (CRC) could be diagnosed in biopsies by measuring the combined expression of a small set of well known genes. Genes were chosen based on their role in either the breakdown of the extracellular matrix or with changes in cellular metabolism both of which are associated with CRC progression Findings Gene expression data derived from quantitative real-time PCR for the solute transporter carriers (SLCs) and the invasion-mediating matrix metalloproteinases (MMPs) were examined using a Linear Descriminant Analysis (LDA). The combination of MMP-7 and SLC5A8 was found to be the most predictive of CRC. Conclusion A combinatorial analysis technique is an effective method for both furthering our understanding on the molecular basis of some aspects of CRC, as well as for leveraging well defined cancer-related gene sets to identify cancer. In this instance, the combination of MMP-7 and SLC5A8 were optimal for identifying CRC. PMID:19689820

  2. Alterations in K-ras, APC and p53-multiple genetic pathway in colorectal cancer among Indians.

    PubMed

    Malhotra, Pooja; Anwar, Mumtaz; Nanda, Neha; Kochhar, Rakesh; Wig, Jai Dev; Vaiphei, Kim; Mahmood, Safrun

    2013-06-01

    The incidence of colorectal cancer (CRC) is increasing rapidly in Asian countries during the past few decades, but no comprehensive analysis has been done to find out the exact cause of this disease. In this study, we investigated the frequencies of mutations and expression pattern of K-ras, APC (adenomatosis polyposis coli) and p53 in tumor, adjoining and distant normal mucosa and to correlate these alterations with patients clinicopathological parameters as well as with the survival. Polymerase chain reaction (PCR)-restriction digestion was used to detect mutations in K-ras and PCR-SSCP (Single Strand Conformation Polymorphism) followed by DNA sequencing was used to detect mutations in APC and p53 genes. Immunohistochemistry was used to detect the expression pattern of K-ras, APC and p53 proteins. The frequencies of mutations of K-ras, APC and p53 in 30 tumor tissues samples were 26.7 %, 46.7 % and 20 %, respectively. Only 3.3 % of tumors contained mutations in all the three genes. The most common combination of mutation was APC and p53 whereas mutation in both p53 and K-ras were extremely rare. There was no association between the mutations and expression pattern of K-ras, APC and p53 (p>0.05). In Indians, the frequency of alterations of K-ras and APC is similar as in Westerns, whereas the frequency of p53 mutation is slightly lower. The lack of multiple mutations in tumor specimens suggests that these genetic alterations might have independent influences on CRC development and there could be multiple alternative genetic pathways to CRC in our present study cohort.

  3. Comprehensive Analysis of miRNome Alterations in Response to Sorafenib Treatment in Colorectal Cancer Cells

    PubMed Central

    Pehserl, Anna-Maria; Ress, Anna Lena; Stanzer, Stefanie; Resel, Margit; Karbiener, Michael; Stadelmeyer, Elke; Stiegelbauer, Verena; Gerger, Armin; Mayr, Christian; Scheideler, Marcel; Hutterer, Georg C.; Bauernhofer, Thomas; Kiesslich, Tobias; Pichler, Martin

    2016-01-01

    MicroRNAs (miRNAs) are master regulators of drug resistance and have been previously proposed as potential biomarkers for the prediction of therapeutic response in colorectal cancer (CRC). Sorafenib, a multi-kinase inhibitor which has been approved for the treatment of liver, renal and thyroid cancer, is currently being studied as a monotherapy in selected molecular subtypes or in combination with other drugs in metastatic CRC. In this study, we explored sorafenib-induced cellular effects in Kirsten rat sarcoma viral oncogene homolog olog (KRAS) wild-type and KRAS-mutated CRC cell lines (Caco-2 and HRT-18), and finally profiled expression changes of specific miRNAs within the miRNome (>1000 human miRNAs) after exposure to sorafenib. Overall, sorafenib induced a time- and dose-dependent growth-inhibitory effect through S-phase cell cycle arrest in KRAS wild-type and KRAS-mutated CRC cells. In HRT-18 cells, two human miRNAs (hsa-miR-597 and hsa-miR-720) and two small RNAs (SNORD 13 and hsa-miR-3182) were identified as specifically sorafenib-induced. In Caco-2 cells, nine human miRNAs (hsa-miR-3142, hsa-miR-20a, hsa-miR-4301, hsa-miR-1290, hsa-miR-4286, hsa-miR-3182, hsa-miR-3142, hsa-miR-1246 and hsa-miR-720) were identified to be differentially regulated post sorafenib treatment. In conclusion, we confirmed sorafenib as a potential anti-neoplastic treatment strategy for CRC cells by demonstrating a growth-inhibitory and cell cycle–arresting effect of this drug. Changes in the miRNome indicate that some specific miRNAs might be relevant as indicators for sorafenib response, drug resistance and potential targets for combinatorial miRNA-based drug strategies. PMID:27916938

  4. Efficiency of olaparib in colorectal cancer patients with an alteration of the homologous repair protein

    PubMed Central

    Ghiringhelli, Francois; Richard, Corentin; Chevrier, Sandy; Végran, Frédérique; Boidot, Romain

    2016-01-01

    Precision medicine is defined by the administration of drugs based on the tumor’s particular genetic characteristics. It is developing quickly in the field of cancer therapy. For example, KRAS, NRAS and BRAF genetic testing demonstrates its efficiency for precision medicine in colorectal cancer (CRC). Besides for these well-known mutations, the purpose of performing larger genetic testing in this pathology is unknown. Recent reports have shown that using the poly ADP ribose polymerase (PARP) inhibitor olaparib in patients with homologous repair enzyme deficiency gave positive clinical results in breast, ovarian and prostate cancers. We have reported here the cases of 2 patients with multi-treated metastatic CRC who underwent somatic and constitutional exome analyses. The analyses revealed a loss of function mutation in a homologous repair enzyme resulting in the loss of heterozygosity for both patients (Check2 for the first patient and RAD51C for the second one). Both patients were treated with off-label usage of olaparib. While the first patient showed clinical benefit, reduction of carcinoembryonic antigen tumor marker and radiologic response, the second patient quickly presented a progression of the tumor. Additional genetic analyses revealed a frameshift truncating mutation of the TP53BP1 gene in the patient who progressed. Interestingly, deficiency in TP53BP1 was previously described to confer resistance to olaparib in mice breast cancer models. Our findings suggest that exome analysis may be a helpful tool to highlight targetable mutations in CRC and that olaparib may be efficient in patients with a homologous repair deficiency. PMID:28082821

  5. Boswellic acid induces epigenetic alterations by modulating DNA methylation in colorectal cancer cells.

    PubMed

    Shen, Yan; Takahashi, Masanobu; Byun, Hyang-Min; Link, Alexander; Sharma, Nupur; Balaguer, Francesc; Leung, Hon-Chiu E; Boland, C Richard; Goel, Ajay

    2012-05-01

    Accumulating evidence suggests that chemopreventive effects of some dietary polyphenols may in part be mediated by their ability to influence epigenetic mechanisms in cancer cells. Boswellic acids, derived from the plant Boswellia serrata, have long been used for the treatment of various inflammatory diseases due to their potent anti-inflammatory activities. Recent preclinical studies have also suggested that this compound has anti-cancer potential against various malignancies. However, the precise molecular mechanisms underlying their anti-cancer effects remain elusive. Herein, we report that boswellic acids modulate DNA methylation status of several tumor suppressor genes in colorectal cancer (CRC) cells. We treated RKO, SW48 and SW480 CRC cell lines with the active principle present in boswellic acids, acetyl-keto-β-boswellic acid (AKBA). Using genome-wide DNA methylation and gene expression microarray analyses, we discovered that AKBA induced a modest genome-wide demethylation that permitted simultaneous re-activation of the corresponding tumor suppressor genes. The quantitative methylation-specific PCR and RT-PCR validated the gene demethylation and re-expression in several putative tumor suppressor genes including SAMD14 and SMPD3. Furthermore, AKBA inhibited DNMT activity in CRC cells. Taken together, these results lend further support to the growing notion that anti-cancer effect of boswellic acids may in part be due to its ability to demethylate and reactivate methylation-silenced tumor suppressor genes. These results suggest that not only boswellic acid might be a promising epigenetic modulator in the chemoprevention and treatment of CRC, but also provide a rationale for future investigations on the usefulness of such botanicals for epigenetic therapy in other human malignancies.

  6. TP53 alterations and colorectal cancer predisposition in south Indian population: a case-control study.

    PubMed

    Singamsetty, Gopi Krishna; Malempati, Sravanthi; Bhogadhi, Srichandana; Kondreddy, Ravinder; Govatati, Suresh; Tangudu, Naveen Kumar; Govatati, Sowdamani; kuraganti, Anil Kumar; Bhanoori, Manjula; Kassetty, Kondaiah

    2014-03-01

    The objective of the present study was to investigate the association between TP53 gene single nucleotide polymorphisms (SNPs) and colorectal cancer (CRC) predisposition in south Indian population and to evaluate the role of TP53 expression in the pathophysiology of CRC. A genetic association study was conducted in 103 CRC cases and 107 controls of south Indian origin. We genotyped ten selected TP53 SNPs by polymerase chain reaction-sequencing analysis. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pairwise linkage disequilibrium (LD) were assessed by Haploview Software. In addition, to better understand the role of TP53 in the pathophysiology of CRC, the expression pattern was evaluated in analogous tumor and normal tissues from 23 CRC patients by Western blot analysis. The frequencies of Pro72Pro (P = 0.0033) genotype and Ser47/Pro72 (P = 0.00171) haplotype were significantly higher in patients as compared to controls. Strong LD was observed between codon 47 and 72 in cases (D' = 0.32) as compared to controls (D' = 0.21). The polymorphism was not observe at the remaining eight SNPs loci analyzed. Furthermore, increased TP53 expression was observed in tumor tissue than in analogous normal tissue of CRC patients. Interestingly, advanced stage tumors showed more elevated TP53 expression compared to early stage tumors. In conclusion, the TP53 Pro72Pro genotype and Ser47/Pro72 haplotype has an increased risk for CRC predisposition in south Indian population. In addition, elevated TP53 expression appears to be useful prognostic marker for CRC.

  7. Efficiency of olaparib in colorectal cancer patients with an alteration of the homologous repair protein.

    PubMed

    Ghiringhelli, Francois; Richard, Corentin; Chevrier, Sandy; Végran, Frédérique; Boidot, Romain

    2016-12-28

    Precision medicine is defined by the administration of drugs based on the tumor's particular genetic characteristics. It is developing quickly in the field of cancer therapy. For example, KRAS, NRAS and BRAF genetic testing demonstrates its efficiency for precision medicine in colorectal cancer (CRC). Besides for these well-known mutations, the purpose of performing larger genetic testing in this pathology is unknown. Recent reports have shown that using the poly ADP ribose polymerase (PARP) inhibitor olaparib in patients with homologous repair enzyme deficiency gave positive clinical results in breast, ovarian and prostate cancers. We have reported here the cases of 2 patients with multi-treated metastatic CRC who underwent somatic and constitutional exome analyses. The analyses revealed a loss of function mutation in a homologous repair enzyme resulting in the loss of heterozygosity for both patients (Check2 for the first patient and RAD51C for the second one). Both patients were treated with off-label usage of olaparib. While the first patient showed clinical benefit, reduction of carcinoembryonic antigen tumor marker and radiologic response, the second patient quickly presented a progression of the tumor. Additional genetic analyses revealed a frameshift truncating mutation of the TP53BP1 gene in the patient who progressed. Interestingly, deficiency in TP53BP1 was previously described to confer resistance to olaparib in mice breast cancer models. Our findings suggest that exome analysis may be a helpful tool to highlight targetable mutations in CRC and that olaparib may be efficient in patients with a homologous repair deficiency.

  8. Comprehensive Analysis of miRNome Alterations in Response to Sorafenib Treatment in Colorectal Cancer Cells.

    PubMed

    Pehserl, Anna-Maria; Ress, Anna Lena; Stanzer, Stefanie; Resel, Margit; Karbiener, Michael; Stadelmeyer, Elke; Stiegelbauer, Verena; Gerger, Armin; Mayr, Christian; Scheideler, Marcel; Hutterer, Georg C; Bauernhofer, Thomas; Kiesslich, Tobias; Pichler, Martin

    2016-12-01

    MicroRNAs (miRNAs) are master regulators of drug resistance and have been previously proposed as potential biomarkers for the prediction of therapeutic response in colorectal cancer (CRC). Sorafenib, a multi-kinase inhibitor which has been approved for the treatment of liver, renal and thyroid cancer, is currently being studied as a monotherapy in selected molecular subtypes or in combination with other drugs in metastatic CRC. In this study, we explored sorafenib-induced cellular effects in Kirsten rat sarcoma viral oncogene homolog olog (KRAS) wild-type and KRAS-mutated CRC cell lines (Caco-2 and HRT-18), and finally profiled expression changes of specific miRNAs within the miRNome (>1000 human miRNAs) after exposure to sorafenib. Overall, sorafenib induced a time- and dose-dependent growth-inhibitory effect through S-phase cell cycle arrest in KRAS wild-type and KRAS-mutated CRC cells. In HRT-18 cells, two human miRNAs (hsa-miR-597 and hsa-miR-720) and two small RNAs (SNORD 13 and hsa-miR-3182) were identified as specifically sorafenib-induced. In Caco-2 cells, nine human miRNAs (hsa-miR-3142, hsa-miR-20a, hsa-miR-4301, hsa-miR-1290, hsa-miR-4286, hsa-miR-3182, hsa-miR-3142, hsa-miR-1246 and hsa-miR-720) were identified to be differentially regulated post sorafenib treatment. In conclusion, we confirmed sorafenib as a potential anti-neoplastic treatment strategy for CRC cells by demonstrating a growth-inhibitory and cell cycle-arresting effect of this drug. Changes in the miRNome indicate that some specific miRNAs might be relevant as indicators for sorafenib response, drug resistance and potential targets for combinatorial miRNA-based drug strategies.

  9. Heparan sulfate proteoglycans undergo differential expression alterations in right sided colorectal cancer, depending on their metastatic character.

    PubMed

    Fernández-Vega, Iván; García-Suárez, Olivia; García, Beatriz; Crespo, Ainara; Astudillo, Aurora; Quirós, Luis M

    2015-10-20

    Heparan sulfate proteoglycans (HSPGs) are complex molecules involved in the growth, invasion and metastatic properties of cancerous cells. This study analyses the alterations in the expression patterns of these molecules in right sided colorectal cancer (CRC), both metastatic and non-metastatic. Twenty right sided CRCs were studied. A transcriptomic approach was used, employing qPCR to analyze both the expression of the enzymes involved in heparan sulfate (HS) chains biosynthesis, as well as the proteoglycan core proteins. Since some of these proteoglycans can also carry chondroitin sulfate (CS) chains, we include the study of the genes involved in the biosynthesis of these glycosaminoglycans. Immunohistochemical techniques were also used to analyze tissue expression of particular genes showing significant expression differences, of potential interest. Changes in proteoglycan core proteins differ depending on their location; those located intracellularly or in the extracellular matrix show very similar alteration patterns, while those located on the cell surface vary greatly depending on the nature of the tumor: glypicans 1, 3, 6 and betaglycan are affected in the non-metastatic tumors, whereas in the metastatic, only glypican-1 and syndecan-1 are modified, the latter showing opposing alterations in levels of RNA and of protein, suggesting post-transcriptional regulation in these tumors. Furthermore, in non-metastatic tumors, polymerization of glycosaminoglycan chains is modified, particularly affecting the synthesis of the tetrasaccharide linker and the initiation and elongation of CS chains, HS chains being less affected. Regarding the enzymes responsible for the modificaton of the HS chains, alterations were only found in non-metastatic tumors, affecting N-sulfation and the isoforms HS6ST1, HS3ST3B and HS3ST5. In contrast, synthesis of the CS chains suggests changes in epimerization and sulfation of the C4 and C2 in both types of tumor. Right sided CRCs show

  10. Transporters for Antiretroviral Drugs in Colorectal CD4+ T Cells and Circulating α4β7 Integrin CD4+ T Cells: Implications for HIV Microbicides.

    PubMed

    Mukhopadhya, Indrani; Murray, Graeme I; Duncan, Linda; Yuecel, Raif; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

    2016-09-06

    CD4+ T lymphocytes in the colorectal mucosa are key in HIV-1 transmission and dissemination. As such they are also the primary target for antiretroviral (ARV)-based rectal microbicides for pre-exposure prophylaxis. Drug transporters expressed in mucosal CD4+ T cells determine ARV distribution across the cell membrane and, most likely, efficacy of microbicides. We describe transporters for antiretroviral drugs in colorectal mucosal CD4+ T lymphocytes and compare gene expression with circulating α4β7+CD4+ T cells, which traffic to the intestine and have been shown to be preferentially infected by HIV-1. Purified total CD4+ T cells were obtained from colorectal tissue and blood samples by magnetic separation. CD4+ T cells expressing α4β7 integrin were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells of healthy volunteers. Expressions of 15 efflux and uptake drug transporter genes were quantified using Taqman qPCR assays. Expression of efflux transporters MRP3, MRP5, and BCRP and uptake transporter CNT2 were significantly higher in colorectal CD4+ T cells compared to circulating CD4+ T cells (p = 0.01-0.03). Conversely, circulating α4β7+CD4+ T cells demonstrated significantly higher expression of OATPD compared to colorectal CD4+ T cells (p = 0.001). To the best of our knowledge this is the first report of drug transporter gene expression in colorectal CD4+ and peripheral α4β7+CD4+ T cells. The qualitative and quantitative differences in drug transporter gene expression profiles between α4β7+CD4+ T cells and total mucosal CD4+ T cells may have significant implications for the efficacy of rectally delivered ARV-microbicides. Most notably, we have identified efflux drug transporters that could be targeted by selective inhibitors or beneficial drug-drug interactions to enhance intracellular accumulation of antiretroviral drugs.

  11. Network signatures of nuclear and cytoplasmic density alterations in a model of pre and postmetastatic colorectal cancer

    NASA Astrophysics Data System (ADS)

    Damania, Dhwanil; Subramanian, Hariharan; Backman, Vadim; Anderson, Eric C.; Wong, Melissa H.; McCarty, Owen J. T.; Phillips, Kevin G.

    2014-01-01

    Cells contributing to the pathogenesis of cancer possess cytoplasmic and nuclear structural alterations that accompany their aberrant genetic, epigenetic, and molecular perturbations. Although it is known that architectural changes in primary and metastatic tumor cells can be quantified through variations in cellular density at the nanometer and micrometer spatial scales, the interdependent relationships among nuclear and cytoplasmic density as a function of tumorigenic potential has not been thoroughly investigated. We present a combined optical approach utilizing quantitative phase microscopy and partial wave spectroscopic microscopy to perform parallel structural characterizations of cellular architecture. Using the isogenic SW480 and SW620 cell lines as a model of pre and postmetastatic transition in colorectal cancer, we demonstrate that nuclear and cytoplasmic nanoscale disorder, micron-scale dry mass content, mean dry mass density, and shape metrics of the dry mass density histogram are uniquely correlated within and across different cellular compartments for a given cell type. The correlations of these physical parameters can be interpreted as networks whose nodal importance and level of connection independence differ according to disease stage. This work demonstrates how optically derived biophysical parameters are linked within and across different cellular compartments during the architectural orchestration of the metastatic phenotype.

  12. Network signatures of nuclear and cytoplasmic density alterations in a model of pre and postmetastatic colorectal cancer.

    PubMed

    Damania, Dhwanil; Subramanian, Hariharan; Backman, Vadim; Anderson, Eric C; Wong, Melissa H; McCarty, Owen J T; Phillips, Kevin G

    2014-01-01

    Cells contributing to the pathogenesis of cancer possess cytoplasmic and nuclear structural alterations that accompany their aberrant genetic, epigenetic, and molecular perturbations. Although it is known that architectural changes in primary and metastatic tumor cells can be quantified through variations in cellular density at the nanometer and micrometer spatial scales, the interdependent relationships among nuclear and cytoplasmic density as a function of tumorigenic potential has not been thoroughly investigated. We present a combined optical approach utilizing quantitative phase microscopy and partial wave spectroscopic microscopy to perform parallel structural characterizations of cellular architecture. Using the isogenic SW480 and SW620 cell lines as a model of pre and postmetastatic transition in colorectal cancer, we demonstrate that nuclear and cytoplasmic nanoscale disorder, micron-scale dry mass content, mean dry mass density, and shape metrics of the dry mass density histogram are uniquely correlated within and across different cellular compartments for a given cell type. The correlations of these physical parameters can be interpreted as networks whose nodal importance and level of connection independence differ according to disease stage. This work demonstrates how optically derived biophysical parameters are linked within and across different cellular compartments during the architectural orchestration of the metastatic phenotype.

  13. Network signatures of nuclear and cytoplasmic density alterations in a model of pre and postmetastatic colorectal cancer

    PubMed Central

    Damania, Dhwanil; Subramanian, Hariharan; Backman, Vadim; Anderson, Eric C.; Wong, Melissa H.; McCarty, Owen J. T.; Phillips, Kevin G.

    2014-01-01

    Abstract. Cells contributing to the pathogenesis of cancer possess cytoplasmic and nuclear structural alterations that accompany their aberrant genetic, epigenetic, and molecular perturbations. Although it is known that architectural changes in primary and metastatic tumor cells can be quantified through variations in cellular density at the nanometer and micrometer spatial scales, the interdependent relationships among nuclear and cytoplasmic density as a function of tumorigenic potential has not been thoroughly investigated. We present a combined optical approach utilizing quantitative phase microscopy and partial wave spectroscopic microscopy to perform parallel structural characterizations of cellular architecture. Using the isogenic SW480 and SW620 cell lines as a model of pre and postmetastatic transition in colorectal cancer, we demonstrate that nuclear and cytoplasmic nanoscale disorder, micron-scale dry mass content, mean dry mass density, and shape metrics of the dry mass density histogram are uniquely correlated within and across different cellular compartments for a given cell type. The correlations of these physical parameters can be interpreted as networks whose nodal importance and level of connection independence differ according to disease stage. This work demonstrates how optically derived biophysical parameters are linked within and across different cellular compartments during the architectural orchestration of the metastatic phenotype. PMID:24441943

  14. RhoA regulates resistance to irinotecan by regulating membrane transporter and apoptosis signaling in colorectal cancer

    PubMed Central

    Ruihua, Huang; Mengyi, Zhang; Chong, Zhao; Meng, Qiu; Xin, Ma; Qiulin, Tang; Feng, Bi; Ming, Liu

    2016-01-01

    Colorectal cancer (CRC) is a major cause of mortality and morbidity worldwide. While surgery remains the mainstay of treatment in early stage CRC, chemotherapy is usually given to prolong the overall survival and improve the quality of life for metastatic colorectal cancer (mCRC). But drug resistance is one of the major hurdles of mCRC treatment, and the underlying mechanisms are still largely unknown. In this study, we show that, compared with parental cells, RhoA is up-regulated in irinotecan (CPT-11)-resistant CRC cells. Furthermore, inhibition of RhoA in drug resistant cells, at least partially, rescues the resistance against irinotecan and increases the sensitivity to other chemotherapeutic drug by inhibiting expression of MDR1, MRP1and GSTP1, promotes apoptosis by suppressing the expression of BCL-XL and Bcl-2 and increasing Bax expression, and significantly decreases side population cells. Our results suggest that, in addition to survival, proliferation, migration, adhesion, cell cycle and gene transcription, RhoA is also involved in chemoresistance by regulating the expression of membrane transporter and apoptosis protein in colorectal cancer. They raise an interesting possibility that the expression of RhoA may indicate a poor prognosis due to the high probability to therapy resistance and, on the other hand, inhibition of RhoA activity and function may overcome chemoresistance and improve the effectiveness of clinical treatment of CRC. PMID:27888624

  15. The effect of body weight on altered expression of nuclear receptors and cyclooxygenase-2 in human colorectal cancers

    PubMed Central

    Delage, Barbara; Rullier, Anne; Capdepont, Maylis; Rullier, Eric; Cassand, Pierrette

    2007-01-01

    Background Epidemiological studies on risk factors for colorectal cancer (CRC) have mainly focused on diet, and being overweight is now recognized to contribute significantly to CRC risk. Overweight and obesity are defined as an excess of adipose tissue mass and are associated with disorders in lipid metabolism. Peroxisome proliferator-activated receptors (PPARs) and retinoid-activated receptors (RARs and RXRs) are important modulators of lipid metabolism and cellular homeostasis. Alterations in expression and activity of these ligand-activated transcription factors might be involved in obesity-associated diseases, which include CRC. Cyclooxygenase-2 (COX-2) also plays a critical role in lipid metabolism and alterations in COX-2 expression have already been associated with unfavourable clinical outcomes in epithelial tumors. The objective of this study is to examine the hypothesis questioning the relationship between alterations in the expression of nuclear receptors and COX-2 and the weight status among male subjects with CRC. Method The mRNA expression of the different nuclear receptor subtypes and of COX-2 was measured in 20 resected samples of CRC and paired non-tumor tissues. The association between expression patterns and weight status defined as a body mass index (BMI) was statistically analyzed. Results No changes were observed in PPARγ mRNA expression while the expression of PPARδ, retinoid-activated receptors and COX-2 were significantly increased in cancer tissues compared to normal colon mucosa (P ≤ 0.001). The weight status appeared to be an independent factor, although we detected an increased level of COX-2 expression in the normal mucosa from overweight patients (BMI ≥ 25) compared to subjects with healthy BMI (P = 0.002). Conclusion Our findings show that alterations in the pattern of nuclear receptor expression observed in CRC do not appear to be correlated with patient weight status. However, the analysis of COX-2 expression in normal colon

  16. Altered regulation of DNA ligase IV activity by aberrant promoter DNA methylation and gene amplification in colorectal cancer.

    PubMed

    Kuhmann, Christine; Li, Carmen; Kloor, Matthias; Salou, Mariam; Weigel, Christoph; Schmidt, Christopher R; Ng, Linda W C; Tsui, Wendy W Y; Leung, Suet Y; Yuen, Siu T; Becker, Natalia; Weichenhan, Dieter; Plass, Christoph; Schmezer, Peter; Chan, Tsun L; Popanda, Odilia

    2014-04-15

    Colorectal cancer (CRC) presents as a very heterogeneous disease which cannot sufficiently be characterized with the currently known genetic and epigenetic markers. To identify new markers for CRC we scrutinized the methylation status of 231 DNA repair-related genes by methyl-CpG immunoprecipitation followed by global methylation profiling on a CpG island microarray, as altered expression of these genes could drive genomic and chromosomal instability observed in these tumors. We show for the first time hypermethylation of MMP9, DNMT3A and LIG4 in CRC which was confirmed in two CRC patient groups with different ethnicity. DNA ligase IV (LIG4) showed strong differential promoter methylation (up to 60%) which coincided with downregulation of mRNA in 51% of cases. This functional association of LIG4 methylation and gene expression was supported by LIG4 re-expression in 5-aza-2'-deoxycytidine-treated colon cancer cell lines, and reduced ligase IV amounts and end-joining activity in extracts of tumors with hypermethylation. Methylation of LIG4 was not associated with other genetic and epigenetic markers of CRC in our study. As LIG4 is located on chromosome 13 which is frequently amplified in CRC, two loci were tested for gene amplification in a subset of 47 cases. Comparison of amplification, methylation and expression data revealed that, in 30% of samples, the LIG4 gene was amplified and methylated, but expression was not changed. In conclusion, hypermethylation of the LIG4 promoter is a new mechanism to control ligase IV expression. It may represent a new epigenetic marker for CRC independent of known markers.

  17. Epigenetics and Colorectal Cancer

    PubMed Central

    Lao, Victoria Valinluck; Grady, William M.

    2012-01-01

    Colorectal cancer is a leading cause of cancer deaths in the world. It results from an accumulation of genetic and epigenetic changes in colon epithelial cells that transforms them into adenocarcinomas. There have been major advances in our understanding of cancer epigenetics over the last decade, particularly regarding aberrant DNA methylation. Assessment of the colon cancer epigenome has revealed that virtually all colorectal cancers have aberrantly methylated genes and the average colorectal cancer methylome has hundreds to thousands of abnormally methylated genes. As with gene mutations in the cancer genome, a subset of these methylated genes, called driver genes, is presumed to play a functional role in colorectal cancer. The assessment of methylated genes in colorectal cancers has also revealed a unique molecular subgroup of colorectal cancers called CpG Island Methylator Phenotype (CIMP) cancers; these tumors have a particularly high frequency of methylated genes. The advances in our understanding of aberrant methylation in colorectal cancer has led to epigenetic alterations being developed as clinical biomarkers for diagnostic, prognostic, and therapeutic applications. Progress in the assessment of epigenetic alterations in colorectal cancer and their clinical applications has shown that these alterations will be commonly used in the near future as molecular markers to direct the prevention and treatment of colorectal cancer. PMID:22009203

  18. ABC-Transporter Expression Does Not Correlate with Response to Irinotecan in Patients with Metastatic Colorectal Cancer.

    PubMed

    Trumpi, K; Emmink, B L; Prins, A M; van Oijen, M G H; van Diest, P J; Punt, C J A; Koopman, M; Kranenburg, O; Rinkes, I H M Borel

    2015-01-01

    Active efflux of irinotecan by ATP-binding cassette (ABC)-transporters, in particular ABCB1 and ABCG2, is a well-established drug resistance mechanism in vitro and in pre-clinical mouse models, but its relevance in colorectal cancer (CRC) patients is unknown. Therefore, we assessed the association between ABC-transporter expression and tumour response to irinotecan in patients with metastatic CRC. Tissue microarrays of a large cohort of metastatic CRC patients treated with irinotecan in a prospective study (CAIRO study; n=566) were analysed for expression of ABCB1 and ABCG2 by immunohistochemistry. Kaplan-Meier and Cox proportional hazard regression analyses were performed to assess the association of ABC transporter expression with irinotecan response. Gene expression profiles of 17 paired tumours were used to assess the concordance of ABCB1/ABCG2 expression in primary CRC and corresponding metastases. The response to irinotecan was not significantly different between primary tumours with positive versus negative expression of ABCB1 (5.8 vs 5.7 months, p=0.696) or ABCG2 (5.7 vs 6.1 months, p=0.811). Multivariate analysis showed neither ABCB1 nor ABCG2 were independent predictors for progression free survival. There was a mediocre to poor concordance between ABC-transporter expression in paired tumours. In metastatic CRC, ABC-transporter expression in the primary tumour does not predict irinotecan response.

  19. Serotonin Transporter Gene (SLC6A4) Variations Are Associated with Poor Survival in Colorectal Cancer Patients

    PubMed Central

    Savas, Sevtap; Hyde, Angela; Stuckless, Susan N.; Parfrey, Patrick; Younghusband, H. Banfield; Green, Roger

    2012-01-01

    Prognosis in colorectal cancer patients is quite variable, even after adjustment for clinical parameters such as disease stage and microsatellite instability status. It is possible that the psychological distress experienced by patients, including anxiety and depression, may be correlated with poor prognosis. In the present study, we hypothesize that genetic variations within three genes biologically linked to the stress response, namely serotonin transporter (SLC6A4), brain-derived neurotrophic factor (BDNF), and arginine vasopressin receptor (AVPR1B) genes are associated with prognosis in colorectal cancer patients. We used a population-based cohort of 280 patients who were followed for up to 12.5 years after diagnosis. Our multivariate analysis showed that a tagSNP in the SLC6A4 gene (rs12150214) was a predictor of shorter overall survival (HR: 1.572, 95%CI: 1.142–2.164, p = 0.005) independent of stage, age, grade and MSI status. Additionally, a multivariate analysis using the combined genotypes of three polymorphisms in this gene demonstrated that the presence of any of the minor alleles at these polymorphic loci was an independent predictor of both shorter overall survival (HR: 1.631, 95%CI: 1.190–2.236, p = 0.002) and shorter disease specific survival (HR: 1.691, 95%CI: 1.138–2.512, p = 0.009). The 5-HTT protein coded by the SLC6A4 gene has also been implicated in inflammation. While our results remain to be replicated in other patient cohorts, we suggest that the genetic variations in the SLC6A4 gene contribute to poor survival in colorectal cancer patients. PMID:22911682

  20. Altered carnitine transport in pressure-overload hypertrophied rat hearts

    SciTech Connect

    O'Rourke, B.; Foster, K.; Reibel, D.K.

    1986-03-01

    The authors have previously observed reduced carnitine levels in hypertrophied hearts of rats subjected to aortic constriction. In an attempt to determine the mechanism for reduced myocardial carnitine content, carnitine transport was examined in isolated perfused hearts. Hearts were excised from sham-operated and aortic-constricted rats 3 weeks following surgery and perfused at 60 mm Hg aortic pressure with buffer containing various concentrations of L-/sup 14/C-carnitine. Carnitine uptake by control and hypertrophied hearts was linear throughout 30 minutes of perfusion with 40 ..mu..M carnitine. Total carnitine uptake was significantly reduced by 25% in hypertrophied hearts at each time point examined. The reduction in uptake by hypertrophied hearts was also evident when hearts were perfused with 100 or 200 ..mu..M carnitine. When 0.05 mM mersalyl acid was included in the buffer to inhibit the carrier-mediated component of transport, no difference in carnitine uptake was observed indicating that the transport of carnitine by diffusion was unaltered in the hypertrophied myocardium. Carrier-mediated carnitine uptake (total uptake - uptake by diffusion) was significantly reduced by approximately 40% in hypertrophied hearts at all concentrations examined. Thus, the reduction in carnitine content in the pressure-overload hypertrophied rat heart appears to be due to a reduction in carrier-mediated carnitine uptake by the heart.

  1. Salt-stress alters proton transport by the tonoplast ATPase

    SciTech Connect

    DuPont, F.; Morrissey, P. )

    1990-05-01

    A tonoplast-enriched membrane fraction was obtained from roots of barley (Hordeum vulgare cv CM72) seedlings grown in half-strength nutrient solution with or without 100 mM NaCl. Proton transport by the tonoplast ATPase was measured using acridine orange, quinacrine or uptake of ({sup 14}C)-methylamine. The Vmax for proton transport was 2 to 4-fold higher for the ATPase from salt-grown compared to control roots. However, the rate of ATP hydrolysis was not significantly different for the two treatments. The percent inhibition of ATP hydrolysis by DCCD, DIDS and KNO{sub 3} was similar for the two treatments, as was the percent stimulation by Cl. The pH optimum for proton transport was more alkaline for the ATPase from salt-grown roots. No difference was observed between membranes from control and salt-grown roots when oxonol fluorescence was used to measure formation of a membrane potential by the ATPase. Immunoblots of SDS gels were reacted with the antibody to the 68-kD subunit from red beet to assess the relative amount of the 68-kD subunit of the tonoplast ATPase from control or salt-grown roots. The relative amount of the 16-kD DCCD-binding subunit was compared by binding of ({sup 14}C)-DCCD. The amounts of the two subunits were not significantly different in membranes from control or salt-grown roots. The increase in rate of formation of the pH gradient was not accounted for by an increase in the amount of the ATPase.

  2. Long-term modeling of alteration-transport coupling: Application to a fractured Roman glass

    NASA Astrophysics Data System (ADS)

    Verney-Carron, Aurélie; Gin, Stéphane; Frugier, Pierre; Libourel, Guy

    2010-04-01

    To improve confidence in glass alteration models, as used in nuclear and natural applications, their long-term predictive capacity has to be validated. For this purpose, we develop a new model that couples geochemical reactions with transport and use a fractured archaeological glass block that has been altered for 1800 years under well-constrained conditions in order to test the capacity of the model. The chemical model considers three steps in the alteration process: (1) formation of a hydrated glass by interdiffusion, whose kinetics are controlled by a pH and temperature dependent diffusion coefficient; (2) the dissolution of the hydrated glass, whose kinetics are based on an affinity law; (3) the precipitation of secondary phases if thermodynamic saturation is reached. All kinetic parameters were determined from experiments. The model was initially tested on alteration experiments in different solutions (pure water, Tris, seawater). It was then coupled with diffusive transport in solution to simulate alteration in cracks within the glass. Results of the simulations run over 1800 years are in good agreement with archaeological glass block observations concerning the nature of alteration products (hydrated glass, smectites, and carbonates) and crack alteration thicknesses. External cracks in direct contact with renewed seawater were altered at the forward dissolution rate and are filled with smectites (400-500 μm). Internal cracks are less altered (by 1 or 2 orders of magnitude) because of the strong coupling between alteration chemistry and transport. The initial crack aperture, the distance to the surface, and sealing by secondary phases account for these low alteration thicknesses. The agreement between simulations and observations thus validates the predictive capacity of this coupled geochemical model and increases more generally the robustness and confidence in glass alteration models to predict long-term behavior of nuclear waste in geological disposal or

  3. Pyrethroid pesticide-induced alterations in dopamine transporter function

    SciTech Connect

    Elwan, Mohamed A.; Richardson, Jason R.; Guillot, Thomas S.; Caudle, W. Michael; Miller, Gary W. . E-mail: gary.miller@emory.edu

    2006-03-15

    Parkinson's disease (PD) is a progressive neurodegenerative disease affecting the nigrostriatal dopaminergic pathway. Several epidemiological studies have demonstrated an association between pesticide exposure and the incidence of PD. Studies from our laboratory and others have demonstrated that certain pesticides increase levels of the dopamine transporter (DAT), an integral component of dopaminergic neurotransmission and a gateway for dopaminergic neurotoxins. Here, we report that repeated exposure (3 injections over 2 weeks) of mice to two commonly used pyrethroid pesticides, deltamethrin (3 mg/kg) and permethrin (0.8 mg/kg), increases DAT-mediated dopamine uptake by 31 and 28%, respectively. Using cells stably expressing DAT, we determined that exposure (10 min) to deltamethrin and permethrin (1 nM-100 {mu}M) had no effect on DAT-mediated dopamine uptake. Extending exposures to both pesticides for 30 min (10 {mu}M) or 24 h (1, 5, and 10 {mu}M) resulted in significant decrease in dopamine uptake. This reduction was not the result of competitive inhibition, loss of DAT protein, or cytotoxicity. However, there was an increase in DNA fragmentation, an index of apoptosis, in cells exhibiting reduced uptake at 30 min and 24 h. These data suggest that up-regulation of DAT by in vivo pyrethroid exposure is an indirect effect and that longer-term exposure of cells results in apoptosis. Since DAT can greatly affect the vulnerability of dopamine neurons to neurotoxicants, up-regulation of DAT by deltamethrin and permethrin may increase the susceptibility of dopamine neurons to toxic insult, which may provide insight into the association between pesticide exposure and PD.

  4. Downregulation of ABC Transporters in Non-neoplastic Tissues Confers Better Prognosis for Pancreatic and Colorectal Cancer Patients

    PubMed Central

    Dvorak, Pavel; Hlavac, Viktor; Mohelnikova-Duchonova, Beatrice; Liska, Vaclav; Pesta, Martin; Soucek, Pavel

    2017-01-01

    Transport of a wide variety of substrates, including xenobiotics, is one of the main functions attributed to human ATP-binding cassette (ABC) proteins. Overexpression of ABC genes is considered to be an important mechanism facilitating the development of chemoresistance. Relationships between the expression levels of ABC genes in tumor tissues and established clinicopathological features were extensively studied previously. The current study tested our hypothesis that the expression levels of ABC genes in non-neoplastic (control) tissues also provide important information in relation to the relevant tumor progression. Expression levels of all human ABC genes (48 protein coding and one pseudogene), measured by qRT-PCR, were bioinformatically analyzed. The data originated from four independently collected cohorts covering three types of tumors - breast, colorectal and pancreatic carcinomas. ABC gene expression profiles (signatures) in non-neoplastic tissues (matched to tumor samples from three different tumor types) were characteristically clustered into three main types - those with the vast majority of the genes downregulated, upregulated or heterogeneously regulated. The clusters with mostly downregulated and upregulated genes were shown to possess significant relations to good and poor prognostic markers, respectively, in pancreatic and colorectal cancers. The present findings support the theory that the expression of ABC genes in non-neoplastic tissues can significantly contribute to tumor pathogenesis. Suggested multi-gene panels, consisting of the reduced number of ABC genes, have the potential to be implemented as new prognostic markers, which are especially urgent in pancreatic cancer. The results can also stimulate further primary research in carcinogenesis. PMID:28819395

  5. Propionate alters ion transport by rabbit distal colon

    SciTech Connect

    Horvath, P.J.; Weiser, M.M.; Duffey, M.E.

    1986-03-01

    The primary anions of the colon are short-chain fatty acids (SCFA) produced by intestinal microorganisms from endogenous secretions and dietary fiber. The effects of the SCFA propionate on ion transport by the epithelium of rabbit distal colon were studied on tissues stripped of underlying musculature and mounted in Ussing chambers. When tissues were bathed with NaCl Ringer's solutions at 37/sup 0/C (5% CO/sub 2/-21mM HCO/sub 3/, pH 7.4) replacement of 33mM Cl/sup -/ in both tissue baths by propionate reduced short-circuit current (Isc) from 86 to 35 ..mu..A/cm/sup 2/ and increased transepithelial conductance (G/sub t/) from 3.6 to 5.6mS/cm/sup 2/. Unidirectional /sup 14/C-propionate flux measurements revealed that this ion was secreted at a rate of 0.5..mu..Eq/cm/sup 2/hr. Intracellular measurements with potential and pH sensitive microelectrodes showed that propionate reduced intracellular pH (PH/sub i/) from 6.84 to 6.68 (P < 0.02), depolarized the apical membrane potential (phi/sub a/) by 4mV (P < 0.02) and decreased the membrane fractional resistance (f/sub R/) from .78 to .71 (P < 0.001). Addition of 0.1mM amiloride to the mucosal bath reversed Isc to -18..mu..A/cm/sup 2/, decreased G/sub t/ to 5.3mS/cm/sup 2/, hyperpolarized phi/sub a/ by 5mV (P < 0.05) and increased f/sub R/ to 0.85 (P < 0.001). Amiloride had no effect on pH/sub i/. These results show that propionate can be secreted by rabbit distal colon and that exposure to this SCFA causes cell acidification and electrophysiological changes consistent with H/sup +/ secretion.

  6. CHROMATOGRAPHIC ALTERATION OF A NONIONIC SURFACTANT MIXTURE DURING TRANSPORT IN DENSE NONAQUEOUS PHASE LIQUID CONTAMINATED SEDIMENT (R826650)

    EPA Science Inventory

    Chromatographic alteration of a nonionic surfactant mixture during transport through DNAPL-contaminated aquifer sediment may occur due to differential loss of oligomers to sediment and to dense nonaqueous phase liquid (DNAPL). These losses may significantly alter the solubilizing...

  7. Removal of Potential Phosphorylation Sites does not Alter Creatine Transporter Response to PKC or Substrate Availability.

    PubMed

    Santacruz, Lucia; Darrabie, Marcus D; Mishra, Rajashree; Jacobs, Danny O

    2015-01-01

    Creatine, Phosphocreatine, and creatine kinases, constitute an energy shuttle that links ATP production in mitochondria with cellular consumption sites. Myocytes and neurons cannot synthesize creatine and depend on uptake across the cell membrane by a specialized transporter to maintain intracellular creatine levels. Although recent studies have improved our understanding of creatine transport in cardiomyocytes, the structural elements underlying the creatine transporter protein regulation and the relevant intracellular signaling processes are unknown. The effects of pharmacological activation of kinases or phosphatases on creatine transport in cardiomyocytes in culture were evaluated. Putative phosphorylation sites in the creatine transporter protein were identified by bioinformatics analyses, and ablated using site-directed mutagenesis. Mutant transporter function and their responses to pharmacological PKC activation or changes in creatine availability in the extracellular environment, were evaluated. PKC activation decreases creatine transport in cardiomyocytes in culture. Elimination of high probability potential phosphorylation sites did not abrogate responses to PKC activation or substrate availability. Modulation of creatine transport in cardiomyocytes is a complex process where phosphorylation at predicted sites in the creatine transporter protein does not significantly alter activity. Instead, non-classical structural elements in the creatine transporter and/or interactions with regulatory subunits may modulate its activity. © 2015 S. Karger AG, Basel.

  8. Preferential Radionuclide Transport in a Tuff with Altered Zones: Micro-scale Mapping

    NASA Astrophysics Data System (ADS)

    Hu, Q.; Liu, X.; Zuo, R.

    2009-12-01

    Understanding radionuclide transport in fractured rock is important for performance assessment of proposed radioactive waste disposal sites. We performed laboratory tests to study water imbibition and radionuclide transport into initially dry tuff by contacting one end of a sample with water containing a mixture of tracers (Re, 99Tc, Sr, Cs, 235U, 237Np, and 242Pu). The tuff sample, collected from Yucca Mountain, Nevada, is a cube 1-cm on each side and has a 1-mm thick altered gray zone embedded within the tuff matrix. Such gray zones are observed to be adjacent to lithophysae and fractures, are primarily quartz and tridymite, and have different hydraulic and chemical properties from the rock matrix. Capillary-driven imbibition transports tracer chemicals away from the imbibing face, causing separation of non-sorbing and sorbing tracers in tuff. Using a micro-scale profiling technique of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), we directly mapped the distribution of radionuclides along the altered zone (as well as transverse to the unaltered matrix). We found that the altered zone shows higher permeability, and less retardation of sorbing radionuclides, than the unaltered matrix, leading to preferential transport along the altered zone. Transverse profiling of the unaltered matrix indicated only limited penetration of strongly sorbing radionuclides, such as Pu.

  9. Altered blood-brain barrier transport in neuro-inflammatory disorders.

    PubMed

    Schenk, Geert J; de Vries, Helga E

    2016-06-01

    During neurodegenerative and neuroinflammatory disorders of the central nervous system (CNS), such as Alzheimer's disease (AD) and multiple sclerosis (MS), the protective function of the blood-brain barrier (BBB) may be severely impaired. The general neuro-inflammatory response, ranging from activation of glial cells to immune cell infiltration that is frequently associated with such brain diseases may underlie the loss of the integrity and function of the BBB. Consequentially, the delivery and disposition of drugs to the brain will be altered and may influence the treatment efficiency of such diseases. Altered BBB transport of drugs into the CNS during diseases may be the result of changes in both specific transport and non-specific transport pathways. Potential alterations in transport routes like adsorptive mediated endocytosis and receptor-mediated endocytosis may affect drug delivery to the brain. As such, drugs that normally are unable to traverse the BBB may reach their target in the diseased brain due to increased permeability. In contrast, the delivery of (targeted) drugs could be hampered during inflammatory conditions due to disturbed transport mechanisms. Therefore, the inventory of the neuro-inflammatory status of the neurovasculature (or recovery thereof) is of utmost importance in choosing and designing an adequate drug targeting strategy under disease conditions. Within this review we will briefly discuss how the function of the BBB can be affected during disease and how this may influence the delivery of drugs into the diseased CNS. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Associations of beta-catenin alterations and MSI screening status with expression of key cell cycle regulating proteins and survival from colorectal cancer.

    PubMed

    Wangefjord, Sakarias; Brändstedt, Jenny; Lindquist, Kajsa Ericson; Nodin, Björn; Jirström, Karin; Eberhard, Jakob

    2013-01-21

    Despite their pivotal roles in colorectal carcinogenesis, the interrelationship and prognostic significance of beta-catenin alterations and microsatellite instability (MSI) in colorectal cancer (CRC) needs to be further clarified. In this paper, we studied the associations between beta-catenin overexpression and MSI status with survival from CRC, and with expression of p21, p27, cyclin D1 and p53, in a large, prospective cohort study. Immunohistochemical MSI-screening status and expression of p21, p27 and p53 was assessed in tissue microarrays with tumours from 557 cases of incident CRC in the Malmö Diet and Cancer Study. Chi Square and Spearman's correlation tests were used to explore the associations between beta-catenin expression, MSI status, clinicopathological characteristics and investigative parameters. Kaplan-Meier analysis and Cox proportional hazards modelling were used to assess the relationship between beta-catenin overexpression, MSI status and cancer specific survival (CSS). Positive MSI screening status was significantly associated with older age, female sex, proximal tumour location, non-metastatic disease, and poor differentiation, and inversely associated with beta-catenin overexpression. Beta-catenin overexpression was significantly associated with distal tumour location, low T-stage and well-differentiated tumours. Patients with MSI tumours had a significantly prolonged CSS in the whole cohort, and in stage III-IV disease, also in multivariable analysis, but not in stage I-II disease. Beta-catenin overexpression was associated with a favourable prognosis in the full cohort and in patients with stage III-IV disease. Neither MSI nor beta-catenin status were predictive for response to adjuvant chemotherapy in curatively treated stage III patients. P53 and p27 expression was positively associated with beta-catenin overexpression and inversely associated with MSI. Cyclin D1 expression was positively associated with MSI and beta

  11. Obesity and Colorectal Cancer.

    PubMed

    Jochem, Carmen; Leitzmann, Michael

    There is strong evidence that modifiable lifestyle factors such as obesity play a key role in colorectal carcinogenesis. Epidemiologic data have consistently reported a positive association between obesity and colorectal cancer. The relative risk associated with general obesity (as assessed by BMI) is higher in men than in women and for cancer of the colon than for cancer of the rectum. Abdominal obesity (as assessed by waist circumference (WC) or waist-to-hip ratio) is associated with an increased risk of colorectal cancer in both sexes, with stronger associations for cancer of the colon than for cancer of the rectum. Plausible biological mechanisms include insulin resistance, hyperinsulinemia, chronic inflammation, altered levels of growth factors, adipocytokines and steroid hormones. In addition to its effect on colorectal cancer incidence, obesity may play a role in colorectal cancer recurrence, treatment outcomes and survival. Understanding the effects of childhood and adolescent obesity and weight change over the life course in relation to future risk of colorectal cancer is incomplete but essential for targeted preventive recommendations. This chapter summarizes the current evidence on the relationship between obesity and colorectal cancer and colorectal adenoma, a common precursor lesion.

  12. [Obesity and colorectal cancer].

    PubMed

    Na, Soo-Young; Myung, Seung-Jae

    2012-01-01

    Obesity worldwide is constantly increasing. Obesity acts as an independent significant risk factor for malignant tumors of various organs including colorectal cancer. Visceral adipose tissue is physiologically more important than subcutaneous adipose tissue. The relative risk of colorectal cancer of obese patients is about 1.5 times higher than the normal-weight individuals, and obesity is also associated with premalignant colorectal adenoma. The colorectal cancer incidence of obese patients has gender-specific and site-specific characteristics that it is higher in men than women and in the colon than rectum. Obesity acts as a risk factor of colorectal carcinogenesis by several mechanisms. Isulin, insulin-like growth factor, leptin, adiponectin, microbiome, and cytokines of chronic inflammation etc. have been understood as its potential mechanisms. In addition, obesity in patients with colorectal cancer negatively affects the disease progression and response of chemotherapy. Although the evidence is not clear yet, there are some reports that weight loss as well as life-modification such as dietary change and physical activity can reduce the risk of colorectal cancer. It is very important knowledge in the point that obesity is a potentially modifiable risk factor that can alter the incidence and outcome of the colorectal cancer.

  13. Molecular alterations of canalicular transport systems in experimental models of cholestasis: possible functional correlations.

    PubMed Central

    Trauner, M.

    1997-01-01

    The discovery of unidirectional, ATP-dependent canalicular transport systems (also termed "export pumps") for bile salts, amphiphilic anionic conjugates, lipophilic cations, and phospholipids has opened new opportunities for understanding biliary physiology and the pathophysiology of cholestasis. In addition, ATP-independent canalicular transport systems for glutathione and bicarbonate contribute to (bile acid-independent) bile formation. Canalicular excretion of bile salts and several non-bile acid organic anions is impaired in various experimental models of cholestasis. Recent cloning of several canalicular transport systems now facilitates studies on their molecular regulation in cholestasis. Although the picture is far from complete, experimental evidence now exists that decreased or even absent expression of canalicular transport proteins may explain impaired transport function resulting in hyperbilirubinemia and cholestasis. With the increasing availability of molecular probes for these transport systems in humans, new information on the molecular regulation of canalicular transport proteins in human cholestatic liver diseases is beginning to emerge and should bring new insights into their pathophysiology and treatment. This article gives an overview on molecular alterations of canalicular transport systems in experimental models of cholestasis and discusses the potential implications of these changes for the pathophysiology of cholestasis. PMID:9626757

  14. Altered Hepatic Transport by Fetal Arsenite Exposure in Diet-Induced Fatty Liver Disease.

    PubMed

    Ditzel, Eric J; Li, Hui; Foy, Caroline E; Perrera, Alec B; Parker, Patricia; Renquist, Benjamin J; Cherrington, Nathan J; Camenisch, Todd D

    2016-07-01

    Non-alcoholic fatty liver disease can result in changes to drug metabolism and disposition potentiating adverse drug reactions. Furthermore, arsenite exposure during development compounds the severity of diet-induced fatty liver disease. This study examines the effects of arsenite potentiated diet-induced fatty liver disease on hepatic transport in male mice. Changes were detected for Mrp2/3/4 hepatic transporter gene expression as well as for Oatp1a4/2b1/1b2. Plasma concentrations of Mrp and Oatp substrates were increased in arsenic exposure groups compared with diet-only controls. In addition, murine embryonic hepatocytes and adult primary hepatocytes show significantly altered transporter expression after exposure to arsenite alone: a previously unreported phenomenon. These data indicate that developmental exposure to arsenite leads to changes in hepatic transport which could increase the risk for ADRs during fatty liver disease.

  15. Genetic variants of human organic anion transporter 4 demonstrate altered transport of endogenous substrates

    PubMed Central

    Shima, James E.; Komori, Takafumi; Taylor, Travis R.; Stryke, Doug; Kawamoto, Michiko; Johns, Susan J.; Carlson, Elaine J.; Ferrin, Thomas E.

    2010-01-01

    Apical reabsorption from the urine has been shown to be important for such processes as the maintenance of critical metabolites in the blood and the excretion of nephrotoxic compounds. The solute carrier (SLC) transporter OAT4 (SLC22A11) is expressed on the apical membrane of renal proximal tubule cells and is known to mediate the transport of a variety of xenobiotic and endogenous organic anions. Functional characterization of genetic variants of apical transporters thought to mediate reabsorption, such as OAT4, may provide insight into the genetic factors influencing the complex pathways involved in drug elimination and metabolite reclamation occurring in the kidney. Naturally occurring genetic variants of OAT4 were identified in public databases and by resequencing DNA samples from 272 individuals comprising 4 distinct ethnic groups. Nine total nonsynonymous variants were identified and functionally assessed using uptake of three radiolabeled substrates. A nonsense variant, R48Stop, and three other variants (R121C, V155G, and V155M) were found at frequencies of at least 2% in an ethnic group specific fashion. The L29P, R48Stop, and H469R variants displayed a complete loss of function, and kinetic analysis identified a reduced Vmax in the common nonsynonymous variants. Plasma membrane levels of OAT4 protein were absent or reduced in the nonfunctional variants, providing a mechanistic reason for the observed loss of function. Characterization of the genetic variants of reabsorptive transporters such as OAT4 is an important step in understanding variability in tubular reabsorption with important implications in innate homeostatic processes and drug disposition. PMID:20668102

  16. Genetic variants of human organic anion transporter 4 demonstrate altered transport of endogenous substrates.

    PubMed

    Shima, James E; Komori, Takafumi; Taylor, Travis R; Stryke, Doug; Kawamoto, Michiko; Johns, Susan J; Carlson, Elaine J; Ferrin, Thomas E; Giacomini, Kathleen M

    2010-10-01

    Apical reabsorption from the urine has been shown to be important for such processes as the maintenance of critical metabolites in the blood and the excretion of nephrotoxic compounds. The solute carrier (SLC) transporter OAT4 (SLC22A11) is expressed on the apical membrane of renal proximal tubule cells and is known to mediate the transport of a variety of xenobiotic and endogenous organic anions. Functional characterization of genetic variants of apical transporters thought to mediate reabsorption, such as OAT4, may provide insight into the genetic factors influencing the complex pathways involved in drug elimination and metabolite reclamation occurring in the kidney. Naturally occurring genetic variants of OAT4 were identified in public databases and by resequencing DNA samples from 272 individuals comprising 4 distinct ethnic groups. Nine total nonsynonymous variants were identified and functionally assessed using uptake of three radiolabeled substrates. A nonsense variant, R48Stop, and three other variants (R121C, V155G, and V155M) were found at frequencies of at least 2% in an ethnic group specific fashion. The L29P, R48Stop, and H469R variants displayed a complete loss of function, and kinetic analysis identified a reduced V(max) in the common nonsynonymous variants. Plasma membrane levels of OAT4 protein were absent or reduced in the nonfunctional variants, providing a mechanistic reason for the observed loss of function. Characterization of the genetic variants of reabsorptive transporters such as OAT4 is an important step in understanding variability in tubular reabsorption with important implications in innate homeostatic processes and drug disposition.

  17. Embryonic Stem Cell Proliferation Stimulated By Altered Anabolic Metabolism From Glucose Transporter 2-Transported Glucosamine

    PubMed Central

    Jung, Jin Hyuk; Iwabuchi, Kumiko; Yang, Zhihong; Loeken, Mary R.

    2016-01-01

    The hexose transporter, GLUT2 (SLC2A2), which is expressed by mouse embryos, is important for survival before embryonic day 10.5, but its function in embryos is unknown. GLUT2 can transport the amino sugar glucosamine (GlcN), which could increase substrate for the hexosamine biosynthetic pathway (HBSP) that produces UDP-N-acetylglucosamine for O-linked N-acetylglucosamine modification (O-GlcNAcylation) of proteins. To understand this, we employed a novel murine embryonic stem cell (ESC) line that, like mouse embryos, expresses functional GLUT2 transporters. GlcN stimulated ESC proliferation in a GLUT2-dependent fashion but did not regulate pluripotency. Stimulation of proliferation was not due to increased O-GlcNAcylation. Instead, GlcN decreased dependence of the HBSP on fructose-6-PO4 and glutamine. Consequently, glycolytic- and glutamine-derived intermediates that are needed for anabolic metabolism were increased. Thus, maternally obtained GlcN may increase substrates for biomass accumulation by embryos, as exogenous GlcN does for GLUT2-expressing ESC, and may explain the need for GLUT2 expression by embryos. PMID:27311888

  18. The alteration of zinc transporter gene expression is associated with inflammatory markers in obese women.

    PubMed

    Noh, Hwayoung; Paik, Hee Young; Kim, Jihye; Chung, Jayong

    2014-04-01

    Obesity, a chronic inflammatory state, is associated with altered zinc metabolism. ZnT and Zip transporters are involved in the regulation of zinc metabolism. This study examined the relationships among obesity, zinc transporter gene expression, and inflammatory markers in young Korean women. The messenger RNA (mRNA) levels of leukocyte zinc transporters between obese (BMI = 28.3 ± 0.5 kg/m(2), n = 35) and nonobese (BMI = 20.7 ± 0.2 kg/m(2), n = 20) women aged 18-28 years were examined using quantitative real-time polymerase chain reaction. Inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukin (IL)-6, were measured in serum by enzyme immunoassay. ZnT1 and Zip1 were the most abundantly expressed zinc transporters in leukocytes. The mRNA levels of many zinc transporters (ZnT4, ZnT5, ZnT9, Zip1, Zip4, and Zip6) were significantly lower in obese women, and expression of these genes was inversely correlated with BMI and body fat percentage. In addition, inflammatory markers (CRP and TNF-α) were significantly higher in obese women. The mRNA levels of ZnT4, Zip1, and Zip6 were inversely correlated with CRP (P < 0.05), and mRNA levels of ZnT4 and ZnT5 were inversely correlated with TNF-α (P < 0.05). In standardized simple regression models, levels of TNF-α and CRP were negatively associated with mRNA levels of zinc transporters such as ZnT4, ZnT5, Zip1, and Zip6 (P < 0.05). These results suggest that the expression of zinc transporters may be altered in obese individuals. Changes in zinc transporters may also be related to the inflammatory state associated with obesity.

  19. Mutational analysis of the CitA citrate transporter from Salmonella typhimurium: altered substrate specificity.

    PubMed

    Shimamoto, T; Negishi, K; Tsuda, M; Tsuchiya, T

    1996-09-13

    The CitA citrate transporter in Salmonella typhimurium is encoded by the citA gene and consists of 434 amino acid residues that probably include 12 membrane-spanning segments [Shimamoto. T., et al. (1991) J. Biochem. 110, 22-28]. CitA mutants with altered substrate specificities were isolated by in vitro mutagenesis using nitrous acid. The mutants could grow on isocitrate as a sole carbon source which normally cannot be transported well by the CitA transporter of S. typhimurium. The mutation sites in the citA gene of the nine mutants were determined to involve single residues at seven sites (one mutation per mutant). The original amino acid residues at these sites (Arg-19, Ala-38, Glu-51, Gly-132, Ala-169, Pro-262 and Leu-271) were identified to be responsible for the altered substrate specificity. All these amino acid residues were conserved in four other homologous citrate transporters from Escherichia coli, Citrobacter amalonaticus and Klebsiella pneumoniae and are suggested to be involved in substrate recognition by the CitA transporter.

  20. Enhanced β-secretase processing alters APP axonal transport and leads to axonal defects

    PubMed Central

    Rodrigues, Elizabeth M.; Weissmiller, April M.; Goldstein, Lawrence S.B.

    2012-01-01

    Alzheimer's disease (AD) is a neurodegenerative disease pathologically characterized by amyloid plaques and neurofibrillary tangles in the brain. Before these hallmark features appear, signs of axonal transport defects develop, though the initiating events are not clear. Enhanced amyloidogenic processing of amyloid precursor protein (APP) plays an integral role in AD pathogenesis, and previous work suggests that both the Aβ region and the C-terminal fragments (CTFs) of APP can cause transport defects. However, it remains unknown if APP processing affects the axonal transport of APP itself, and whether increased APP processing is sufficient to promote axonal dystrophy. We tested the hypothesis that β-secretase cleavage site mutations of APP alter APP axonal transport directly. We found that the enhanced β-secretase cleavage reduces the anterograde axonal transport of APP, while inhibited β-cleavage stimulates APP anterograde axonal transport. Transport behavior of APP after treatment with β- or γ-secretase inhibitors suggests that the amount of β-secretase cleaved CTFs (βCTFs) of APP underlies these transport differences. Consistent with these findings, βCTFs have reduced anterograde axonal transport compared with full-length, wild-type APP. Finally, a gene-targeted mouse with familial AD (FAD) Swedish mutations to APP, which enhance the β-cleavage of APP, develops axonal dystrophy in the absence of mutant protein overexpression, amyloid plaque deposition and synaptic degradation. These results suggest that the enhanced β-secretase processing of APP can directly impair the anterograde axonal transport of APP and are sufficient to lead to axonal defects in vivo. PMID:22843498

  1. Alterations in adult behavioral responses to cocaine and dopamine transporters following juvenile exposure to methamphetamine.

    PubMed

    McFadden, Lisa; Yamamoto, Bryan K; Matuszewich, Leslie

    2011-01-20

    The present experiment assessed whether preadolescent exposure to methamphetamine would alter adult behavioral responses to cocaine and dopamine transporter immunoreactivity in the striatum of male and female rats. Juvenile rats were injected once daily with 0 or 2 mg/kg methamphetamine from postnatal days 21 to 35 and tested in adulthood. Male rats, but not female rats, exposed to methamphetamine showed an increase in responsiveness to cocaine in the open field and an increase in dopamine transporter immunoreactivity in the striatum. These findings suggest that early exposure to methamphetamine can lead to sex specific altered responses to psychostimulants in adulthood, which may contribute to later vulnerability to drug use. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Altered Regulation of Hepatic Efflux Transporters Disrupts Acetaminophen Disposition in Pediatric Nonalcoholic Steatohepatitis

    PubMed Central

    Canet, Mark J.; Merrell, Matthew D.; Hardwick, Rhiannon N.; Bataille, Amy M.; Campion, Sarah N.; Ferreira, Daniel W.; Xanthakos, Stavra A.; Manautou, Jose E.; Hesham A-Kader, H.; Erickson, Robert P.

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, representing a spectrum of liver pathologies that include simple hepatic steatosis and the more advanced nonalcoholic steatohepatitis (NASH). The current study was conducted to determine whether pediatric NASH also results in altered disposition of acetaminophen (APAP) and its two primary metabolites, APAP-sulfate and APAP-glucuronide. Pediatric patients with hepatic steatosis (n = 9) or NASH (n = 3) and healthy patients (n = 12) were recruited in a small pilot study design. All patients received a single 1000-mg dose of APAP. Blood and urine samples were collected at 1, 2, and 4 hours postdose, and APAP and APAP metabolites were determined by high-performance liquid chromatography. Moreover, human liver tissues from patients diagnosed with various stages of NAFLD were acquired from the Liver Tissue Cell Distribution System to investigate the regulation of the membrane transporters, multidrug resistance–associated protein 2 and 3 (MRP2 and MRP3, respectively). Patients with the more severe disease (i.e., NASH) had increased serum and urinary levels of APAP-glucuronide along with decreased serum levels of APAP-sulfate. Moreover, an induction of hepatic MRP3 and altered canalicular localization of the biliary efflux transporter, MRP2, describes the likely mechanism for the observed increase in plasma retention of APAP-glucuronide, whereas altered regulation of sulfur activation genes may explain decreased sulfonation activity in NASH. APAP-glucuronide and APAP-sulfate disposition is altered in NASH and is likely due to hepatic membrane transporter dysregulation as well as altered intracellular sulfur activation. PMID:25788542

  3. Altered regulation of hepatic efflux transporters disrupts acetaminophen disposition in pediatric nonalcoholic steatohepatitis.

    PubMed

    Canet, Mark J; Merrell, Matthew D; Hardwick, Rhiannon N; Bataille, Amy M; Campion, Sarah N; Ferreira, Daniel W; Xanthakos, Stavra A; Manautou, Jose E; A-Kader, H Hesham; Erickson, Robert P; Cherrington, Nathan J

    2015-06-01

    Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, representing a spectrum of liver pathologies that include simple hepatic steatosis and the more advanced nonalcoholic steatohepatitis (NASH). The current study was conducted to determine whether pediatric NASH also results in altered disposition of acetaminophen (APAP) and its two primary metabolites, APAP-sulfate and APAP-glucuronide. Pediatric patients with hepatic steatosis (n = 9) or NASH (n = 3) and healthy patients (n = 12) were recruited in a small pilot study design. All patients received a single 1000-mg dose of APAP. Blood and urine samples were collected at 1, 2, and 4 hours postdose, and APAP and APAP metabolites were determined by high-performance liquid chromatography. Moreover, human liver tissues from patients diagnosed with various stages of NAFLD were acquired from the Liver Tissue Cell Distribution System to investigate the regulation of the membrane transporters, multidrug resistance-associated protein 2 and 3 (MRP2 and MRP3, respectively). Patients with the more severe disease (i.e., NASH) had increased serum and urinary levels of APAP-glucuronide along with decreased serum levels of APAP-sulfate. Moreover, an induction of hepatic MRP3 and altered canalicular localization of the biliary efflux transporter, MRP2, describes the likely mechanism for the observed increase in plasma retention of APAP-glucuronide, whereas altered regulation of sulfur activation genes may explain decreased sulfonation activity in NASH. APAP-glucuronide and APAP-sulfate disposition is altered in NASH and is likely due to hepatic membrane transporter dysregulation as well as altered intracellular sulfur activation. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  4. Identification of hydrophobic proteins as biomarker candidates for colorectal cancer.

    PubMed

    Alvarez-Chaver, Paula; Rodríguez-Piñeiro, Ana M; Rodríguez-Berrocal, Francisco J; Martínez-Zorzano, Vicenta S; Páez de la Cadena, María

    2007-01-01

    Nowadays, colorectal cancer is one of the major causes of cancer death in Western countries. Due to the lack of biomarkers with clinical utility for this pathology, and considering that membrane and hydrophobic proteins have not been studied in depth, we performed a prefractionation of colorectal tissues prior to two-dimensional gel electrophoresis in order to identify hydrophobic proteins differentially expressed in colorectal cancer patients. Fractions enriched in hydrophobic proteins were obtained from healthy mucosa and tumor tissue by a specific extraction method based on temperature-dependent phase partitioning with Triton X-114. Proteins were separated by two-dimensional gel electrophoresis and gels were silver-stained, scanned and compared using the PDQuest software. Those spots presenting significantly different abundance were submitted to mass spectrometry for protein identification. Alterations in the expression of cytoskeletal proteins, including a decrease of vimentin and the absence of desmin, were found. We also detected alterations in antioxidant and transport proteins, chaperones, and in two isoforms of the calcium-binding protein S100A6. On the other hand, vimentin was chosen to corroborate the electrophoretic results by specific immunodetection. Most of the altered proteins have been related to cellular membranes, many of them to lipid rafts microdomains in the plasma membrane, and they have also been implicated in the control of cell proliferation, apoptosis, or metastasis. In conclusion, all the proteins found altered in colorectal tumor samples could be considered as candidates for future studies focused on their utility as markers for colorectal diagnosis and prognosis, or as targets for colorectal cancer therapy.

  5. Aging alters mRNA expression of amyloid transporter genes at the blood-brain barrier.

    PubMed

    Osgood, Doreen; Miller, Miles C; Messier, Arthur A; Gonzalez, Liliana; Silverberg, Gerald D

    2017-09-01

    Decreased clearance of potentially toxic metabolites, due to aging changes, likely plays a significant role in the accumulation of amyloid-beta (Aβ) peptides and other macromolecules in the brain of the elderly and in the patients with Alzheimer's disease (AD). Aging is the single most important risk factor for AD development. Aβ transport receptor proteins expressed at the blood-brain barrier are significantly altered with age: the efflux transporters lipoprotein receptor-related protein 1 and P-glycoprotein are reduced, whereas the influx transporter receptor for advanced glycation end products is increased. These receptors play an important role in maintaining brain biochemical homeostasis. We now report that, in a rat model of aging, gene transcription is altered in aging, as measured by Aβ receptor gene messenger RNA (mRNA) at 3, 6, 9, 12, 15, 20, 30, and 36 months. Gene mRNA expression from isolated cerebral microvessels was measured by quantitative polymerase chain reaction. Lipoprotein receptor-related protein 1 and P-glycoprotein mRNA were significantly reduced in aging, and receptor for advanced glycation end products was increased, in parallel with the changes seen in receptor protein expression. Transcriptional changes appear to play a role in aging alterations in blood-brain barrier receptor expression and Aβ accumulation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Adjuvant treatments do not alter the quality of life in elderly patients with colorectal cancer: a population-based study.

    PubMed

    Bouvier, Anne-Marie; Jooste, Valérie; Bonnetain, Franck; Cottet, Vanessa; Bizollon, Marie-Hélène; Bernard, Marie-Pierre; Faivre, Jean

    2008-08-15

    The current study was performed to longitudinally assess the impact of adjuvant treatments on the quality of life (QoL) of elderly colorectal cancer survivors. The Burgundy Digestive Cancer Registry was used to select all patients aged > or =75 years who were diagnosed with colorectal cancer between 2003 and 2005. A total of 209 patients were asked to complete questionnaires during the first year after diagnosis: at the time of inclusion in the study (Q0), at 3 months after the initial diagnosis (Q3), at 6 months after the initial diagnosis (Q6), and at 12 months after the initial diagnosis (Q12) using the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30. A total of 125 patients (60%) responded. Mixed model analyses of variance for repeated measurement were used to compare QoL scores according to therapeutic schemes. Interactions between time of follow-up and treatment were tested. Patient sex, age, location of the tumor, and TNM stage of disease did not appear to differ significantly between respondents and nonrespondents. Global Health and Emotional Functioning improved for colon cancer survivors between Q0 and Q12, and were noted to improve between Q3 and Q12 for rectal cancer patients. According to French recommendations, patients who received chemotherapy for stage III colon cancer (P = .176) or radiotherapy for rectal cancer (P = .959) reported no significant changes in Global Health compared with those patients not receiving adjuvant therapies. Patients treated with chemotherapy reported better Physical Functioning than patients who did not received chemotherapy (P = .0113). To the authors' knowledge, the current study is the first to examine trends over time with regard to the influence of adjuvant treatments for colon and rectal cancers on QoL in a general aged population. Providing evidence that adjuvant chemotherapy for colon cancer has no negative impact on the QoL of elderly patients is of great significance in encouraging

  7. Dopamine transporter site-directed mutations differentially alter substrate transport and cocaine binding.

    PubMed Central

    Kitayama, S; Shimada, S; Xu, H; Markham, L; Donovan, D M; Uhl, G R

    1992-01-01

    Polar amino acids lying within three hydrophobic regions of the dopamine transporter (DAT) are analogous to those important for ligand recognition by catecholamine receptors. Possible functional significance of these amino acids was examined by expressing DAT cDNAs mutated in these polar residues. Replacement of aspartate at position 79 with alanine, glycine, or glutamate dramatically reduced uptake of [3H]dopamine and the tritium-labeled Parkinsonism-inducing neurotoxin 1-methyl-4-phenylpyridinium (MPP+) and reduced the mutants' affinity for the tritium-labeled cocaine analog (-)-2 beta-carbomethoxy-3 beta-(4-fluorophenyl)tropane (CFT) without affecting Bmax. Replacement of the serine residues at positions 356 and 359 in the seventh hydrophobic region by alanine or glycine caused reductions in [3H]dopamine and [3H]MPP+ uptake, whereas [3H]CFT binding was less affected. Substitution of two serines in the eighth hydrophobic region yielded wild-type values for [3H]dopamine and [3H]MPP+ uptake and [3H]CFT binding. These results demonstrate that aspartate and serine residues lying within the first and seventh hydrophobic putative transmembrane regions are crucial for DAT function and provide identification of residues differentially important for cocaine binding and for dopamine uptake. PMID:1502198

  8. Alterations to oxidative stress markers in dogs after a short-term stress during transport.

    PubMed

    Ferreira, Chayanne S; Vasconcellos, Ricardo S; Pedreira, Raquel S; Silva, Flavio L; Sá, Fabiano C; Kroll, Fernanda S A; Maria, Ana P J; Venturini, Katiani S; Carciofi, Aulus C

    2014-01-01

    While methods to evaluate antioxidant capacity in animals exist, one problem with the models is induction of oxidative stress. It is necessary to promote a great enough challenge to induce measurable alterations to oxidative parameters while ensuring the protocol is compatible with animal welfare. The aim of the present study was to evaluate caged transport as a viable short-term stress that would significantly affect oxidative parameters. Twenty adult Beagle dogs, maintained on the same diet for 60 d prior to the transport, were included in the study. To simulate the stress, the dogs were housed in pairs in transport cages (1·0 m × 1·0 m × 1·5 m), placed on a truck coupled to a trailer and transported for a period of 15 min. Blood collection was performed immediately before and again 3 h after the transportation to evaluate oxidative parameters in blood serum, including thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), sequestration activity of the radical 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), protein carbonylation (PC), total sulfhydryl groups (SH), alpha-tocopherol (αToc) and retinol (Ret). PC, SH and αToc were not significantly changed in the study; however, TBARS, TAC and DPPH increased, whereas Ret decreased after the transport. Although the lack of a control group of dogs not submitted to transport is a limitation to be considered, we conclude that the transport model is effective in inducing an antioxidant response in dogs and relevant blood parameters show sensitivity to this proposed model.

  9. Glutathione (GSH) depletion: Effect on chromate (Cr)-induced alterations of renal plasma membrane transport

    SciTech Connect

    Ansari, R.A.; Thakran, R.S.; Berndt, W.O. )

    1991-03-11

    In this study, renal membrane vesicles were isolated from control Sprague Dawley rats, and those treated with DEM DEM+BSO, DEM+Cr and DEM+BSO+Cr. GSH depletors were given 45 min before Cr and the rats sacrificed 3 hr later. Renal GSH was measured and membrane vesicles isolated by Percoll gradient centrifugation. GSH depletion by DEM alone had no effect on BL PAH transport or BB glucose transport. PAH overshoot was absent when Cr was given after DEM, as was true when Cr was given alone, and glucose transport was reduced modestly. GSH depletion by DEM+BSO did not markedly alter either PAH or glucose transport. When Cr was administered after DEM+BSO, the PAH overshoot was eliminated completely, and a reduced glucose transport was seen compared to Cr-DEM and Cr alone. These data suggest that the greater GSH depletion with DEM+BSO permitted an effect of Cr not seen in controls or DEM treated rats.

  10. Colorectal Cancer

    MedlinePlus

    ... rectum are part of the large intestine. Colorectal cancer occurs when tumors form in the lining of ... men and women. The risk of developing colorectal cancer rises after age 50. You're also more ...

  11. Norepinephrine transporter knock-out alters expression of the genes connected with antidepressant drugs action.

    PubMed

    Solich, Joanna; Kolasa, Magdalena; Kusmider, Maciej; Faron-Gorecka, Agata; Pabian, Paulina; Zurawek, Dariusz; Szafran-Pilch, Kinga; Dziedzicka-Wasylewska, Marta

    2015-01-12

    Norepinephrine transporter knock-out mice (NET-KO) exhibit depression-resistant phenotypes. They manifest significantly shorter immobility times in both the forced swim test and the tail suspension test. Moreover, biochemical studies have revealed the up-regulation of other monoamine transporters (dopamine and serotonin) in the brains of NET-KO mice, similar to the phenomenon observed after the chronic pharmacological blockade of norepinephrine transporter by desipramine in wild-type (WT) animals. NET-KO mice are also resistant to stress, as we demonstrated previously by measuring plasma corticosterone concentration. In the present study, we used a microdissection technique to separate target brain regions and the TaqMan Low Density Array approach to test the expression of a group of genes in the NET-KO mice compared with WT animals. A group of genes with altered expression were identified in four brain structures (frontal and cingulate cortices, dentate gyrus of hippocampus and basal-lateral amygdala) of NET-KO mice compared with WT mice. These genes are known to be altered by antidepressant drugs administration. The most interesting gene is Crh-bp, which modulates the activity of corticotrophin--releasing hormone (CRH) and several CRH-family members. Generally, genetic disturbances within noradrenergic neurons result in biological changes, such as in signal transduction and intercellular communication, and may be linked to changes in noradrenaline levels in the brains of NET-KO mice.

  12. Expression and localization of the immunophilin FKBP51 in colorectal carcinomas and primary metastases, and alterations following oxaliplatin-based chemotherapy

    PubMed Central

    Rotoli, Deborah; Morales, Manuel; Del Carmen Maeso, María; Del Pino García, María; Morales, Araceli; Ávila, Julio; Martín-Vasallo, Pablo

    2016-01-01

    The immunophilin FK506-binding protein 5 (FKBP51) is a scaffold protein that serves a pivotal role in the regulation of multiple signaling pathways, integrating external and internal stimuli into distinct signal outputs. In a previous study, we identified several genes that are significantly up- or downregulated in the peripheral white cells (PWCs) of colorectal adenocarcinoma (CRC) patients undergoing oxaliplatin-based chemotherapy. In our screening, FKBP51 gene expression was downregulated following chemotherapy. In order to determine whether this alteration in gene expression observed in PWCs may be detected at the protein level in tumors and metastases following the administration of adjuvant chemotherapy, an immunohistochemical analysis of FKBP51 in CRC and primary metastasis tissues was performed. The present study confirmed the downregulation of FKBP51 gene expression elicited by chemotherapy with folinic acid (leucovorin), fluorouracil and oxaliplatin in metastasized liver tissue that had been resected after the oxaliplatin-based chemotherapy, compared with tissue section samples of CRC from patients (prior to antineoplastic treatment). Furthermore, the results indicated that, in CRC tissue sections, the expression of FKBP51 protein is associated with an immature phenotype of stromal fibroblasts and with the epithelial-to-mesenchymal transition (EMT) phenotype, suggesting a role for this protein in the EMT process in CRC. Finally, the observation that only certain cells of the stroma express FKBP51 protein suggests a potential role for this immunophilin as a stroma cell subtype marker. PMID:27446431

  13. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression

    PubMed Central

    Xue, Liang-Jiao; Frost, Christopher J.; Tsai, Chung-Jui; Harding, Scott A.

    2016-01-01

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability. PMID:27641356

  14. Drought response transcriptomes are altered in poplar with reduced tonoplast sucrose transporter expression.

    PubMed

    Xue, Liang-Jiao; Frost, Christopher J; Tsai, Chung-Jui; Harding, Scott A

    2016-09-19

    Transgenic Populus tremula x alba (717-1B4) plants with reduced expression of a tonoplast sucrose efflux transporter, PtaSUT4, exhibit reduced shoot growth compared to wild type (WT) under sustained mild drought. The present study was undertaken to determine whether SUT4-RNAi directly or indirectly altered poplar predisposition and/or response to changes in soil water availability. While sucrose and hexose levels were constitutively elevated in shoot organs, expression responses to drought were most altered in the root tips of SUT4-RNAi plants. Prior to any drought treatment, constitutively elevated transcript levels of abscisic acid biosynthetic genes and bark/vegetative storage proteins suggested altered metabolism in root tips of RNAi plants. Stronger drought-stimulation of stress-inducible genes encoding late-embryogenesis-abundant proteins in transgenic roots was consistent with increased vulnerability to soil drying. Transcript evidence suggested an RNAi effect on intercellular water trafficking by aquaporins in stem xylem during soil drying and recovery. Co-expression network analysis predicted altered integration of abscisic acid sensing/signaling with ethylene and jasmonate sensing/signaling in RNAi compared to WT roots. The overall conclusion is that steepened shoot-root sugar gradient in RNAi plants increased sensitivity of root tips to decreasing soil water availability.

  15. Altered effect of dopamine transporter 3'UTR VNTR genotype on prefrontal and striatal function in schizophrenia.

    PubMed

    Prata, Diana P; Mechelli, Andrea; Picchioni, Marco M; Fu, Cynthia H Y; Toulopoulou, Timothea; Bramon, Elvira; Walshe, Muriel; Murray, Robin M; Collier, David A; McGuire, Philip

    2009-11-01

    The dopamine transporter plays a key role in the regulation of central dopaminergic transmission, which modulates cognitive processing. Disrupted dopamine function and impaired executive processing are robust features of schizophrenia. To examine the effect of a polymorphism in the dopamine transporter gene (the variable number of tandem repeats in the 3' untranslated region) on brain function during executive processing in healthy volunteers and patients with schizophrenia. We hypothesized that this variation would have a different effect on prefrontal and striatal activation in schizophrenia, reflecting altered dopamine function. Case-control study. Psychiatric research center. Eighty-five subjects, comprising 44 healthy volunteers (18 who were 9-repeat carriers and 26 who were 10-repeat homozygotes) and 41 patients with DSM-IV schizophrenia (18 who were 9-repeat carriers and 23 who were 10-repeat homozygotes). Regional brain activation during word generation relative to repetition in an overt verbal fluency task measured by functional magnetic resonance imaging. Main effects of genotype and diagnosis on activation and their interaction were estimated with analysis of variance in SPM5. Irrespective of diagnosis, the 10-repeat allele was associated with greater activation than the 9-repeat allele in the left anterior insula and right caudate nucleus. Trends for the same effect in the right insula and for greater deactivation in the rostral anterior cingulate cortex were also detected. There were diagnosis x genotype interactions in the left middle frontal gyrus and left nucleus accumbens, where the 9-repeat allele was associated with greater activation than the 10-repeat allele in patients but not controls. Insular, cingulate, and striatal function during an executive task is normally modulated by variation in the dopamine transporter gene. Its effect on activation in the dorsolateral prefrontal cortex and ventral striatum is altered in patients with schizophrenia

  16. Modulation of sulfate renal transport by alterations in cell membrane fluidity.

    PubMed

    Lee, H J; Balasubramanian, S V; Murer, H; Biber, J; Morris, M E

    1999-10-01

    Changes in membrane fluidity have been shown to alter the sodium-dependent renal transport of glucose and phosphate; however, this has not been examined for sodium/sulfate cotransport in the renal proximal tubule. Sodium/sulfate cotransport regulates the homeostasis of sulfate in mammals. The objective of this study was to investigate the influence of alterations of membrane fluidity on sodium-coupled sulfate transport in the Madin-Darby canine kidney cells, which have been stably transfected with sodium/sulfate cotransporter (NaSi-1) cDNA (MDCK-Si). Preincubation of cells with 0. 2 mM cholesterol significantly decreased the V(max) for sodium/sulfate cotransport (13.69 +/- 1.11 vs 10.15 +/- 1.17 nmol/mg protein/5 min, mean +/- SD, n = 4, p < 0.01) with no significant alteration in K(m). The addition of benzyl alcohol (20 mM) to cells increased the V(max) of sulfate uptake by 20% (11.97 +/- 0.91 vs 14. 35 +/- 0.56 nmol/mg protein/5 min, mean +/- SD, n = 3, p < 0.05) with no significant change in K(m). Membrane fluidity, as measured by the fluorescence polarization of 1,6-diphenyl 1,3,5-hexatriene (DPH), was significantly increased in MDCK-Si cells treated with 20 mM benzyl alcohol and decreased in the cells preincubated with 0.2 mM cholesterol, compared with control cells. Our results suggest that alterations in membrane fluidity that may occur as a result of disease states, aging, and pregnancy may play an important role in the modulation of renal sodium/sulfate cotransport.

  17. Alterations in gut transport of minerals and in binding proteins during simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Bikle, D. D.

    1984-01-01

    The structural components of the skeleton develop and are maintained in a 1 g environment, shaped by the mechanical load to which they are constantly exposed. Altering such a mechanical load by reducing the gravitational force imposed on the system, as in space flight, has profound effects on the skeleton and permits an exploration of the molecular events which regulate normal skeletal homeostasis. The objective was to determine whether simulated weightlessness reduced intestinal calcium transport, and if so, to determine the molecular mechanisms for such an effect. A nonstressful tail suspension in which the rats gained weight normally while suspended was used to simulate weightlessness. A significant change in intestinal calcium transport was not demonstrated. However, a cyclic change in bone formation with suspension was shown. Based on these observations, the objective changed to determination of the hormonal regulation of bone formation during simulated weightlessness.

  18. Evaluation of groundwater and phosphorus transport in fractured altered wetland soils

    NASA Astrophysics Data System (ADS)

    Sade, R.; Litaor, M. I.; Shenker, M.

    2010-10-01

    SummaryNutrient loss from altered wetlands to waterways may influence the water quality of downstream water resources. To test potential nutrient transport from a highly fractured agricultural field of altered wetland to waterways, we computed water and solute budgets in a large field (320 ha) experiment. The water level was raised in a drainage canal for 28 days (raising stage) to generate water flow to the field and then lowered (drainage stage) to generate back flow to the canal. Differential sampling stations (DISS) equipped with an Eh-pH measuring system were installed to monitor and sample crack and matrix water separately. Water flowing in cracks exhibited Eh > 250 mV and EC < 1.5 dS m -1 while in the matrix, the Eh was <100 mV and EC exceeded 3.0 dS m -1. High similarity was found between crack water measured in the DISS and water that drained directly into the drainage canal. We proposed a conceptual model for water and solute transport by a dual-domain system. Most of the water flow occurs in the cracks and most of the solute reaches the cracks by advection and diffusive flow mechanisms in the soil matrix. The conceptual model is based on the assumption that the crack and matrix domains are in chemical disequilibrium because of low transport rate from the matrix to the cracks relative to water flow rate in the cracks. Using this conceptual model, we calculated that during the drainage stage, only 0.64 kg P, compared with 3700 kg of the non-sorptive sulfate ion, were transported from the field to the canal. The oxidized conditions in the crack walls lead to Fe-hydroxide precipitation. These fresh precipitate amorphous iron hydroxides serve as an adsorption sink to P and other potential adsorbates.

  19. Disease-Induced Alterations in Brain Drug Transporters in Animal Models of Alzheimer's Disease.

    PubMed

    Vellonen, Kati-Sisko; Ihalainen, Jouni; Boucau, Marie-Christine; Gosselet, Fabien; Picardat, Théo; Gynther, Mikko; Kanninen, Katja M; White, Anthony R; Malm, Tarja; Koistinaho, Jari; Forsberg, Markus M; Ruponen, Marika

    2017-09-26

    Alzheimer's disease (AD) may disturb functions of the blood-brain barrier and change the disposition of drugs to the brain. This study assessed the disease-induced changes in drug transporters in the brain capillaries of transgenic AD mice. Eighteen drug transporters and four tight junction-associated proteins were analyzed by RT-qPCR in cortex, hippocampus and cerebellum tissue samples of 12-16-month-old APdE9, Tg2576 and APP/PS1 transgenic mice and their healthy age-matched controls. In addition, microvessel fractions enriched from 1-3-month-old APdE9 mice were analyzed using RT-qPCR and Western blotting. Brain transport of methotrexate in APdE9 mice was assessed by in vivo microdialysis. The expression profiles of studied genes were similar in brain tissues of AD and control mice. Instead, in the microvessel fraction in APdE9 mice, >2-fold alterations were detected in the expressions of 11 genes but none at the protein level. In control mice strains, >5-fold changes between different brain regions were identified for Slc15a2, Slc22a3 and occludin. Methotrexate distribution into hippocampus of APdE9 mice was faster than in controls. The expression profile of mice carrying presenilin and amyloid precursor protein mutations is comparable to controls, but clear regional differences exist in the expression of drug transporters in brain.

  20. Assessment of the Relation between the Expression of Oxaliplatin Transporters in Colorectal Cancer and Response to FOLFOX-4 Adjuvant Chemotherapy: A Case Control Study

    PubMed Central

    Le Roy, Bertrand; Tixier, Lucie; Pereira, Bruno; Sauvanet, Pierre; Buc, Emmanuel; Pétorin, Caroline; Déchelotte, Pierre; Pezet, Denis; Balayssac, David

    2016-01-01

    Background Adjuvant chemotherapy for colorectal cancer is mainly based on the combination of 5-fluorouracil, folinic acid and oxaliplatin (FOLFOX-4). The pharmacological target of oxaliplatin remains intracellular and therefore dependent on its entry into cells. The intracellular distribution of oxaliplatin is mediated by organic cation transporters 1, 2 and 3 (OCT1, 2 and 3), copper transporter 1 (CTR1) and ATPase Cu2+ transporting beta polypeptide (ATP7B) and may modulate the efficacy of oxaliplatin-based chemotherapy. The aim of this study was to perform a retrospective study to assess the relation between the expression of oxaliplatin transporters in colorectal cancer before chemotherapy and the response to FOLFOX-4 adjuvant chemotherapy in responder and non-responder patients. Methods This retrospective study was conducted at a single center (University Hospital of Clermont-Ferrand, France). The target population was patients with resectable colorectal cancer operated between 2006 and 2013. Inclusion criteria were defined for the responder patients as no cancer recurrence 3 years after the end of chemotherapy, and for the non-responder patients as cancer recurrence within 1 year. Other inclusion criteria were stages IIb–IV cancers, first-line adjuvant FOLFOX-4 chemotherapy, and the availability of resected primary tumor samples. Exclusion criteria were preoperative chemotherapy and/or radiotherapy, a targeted therapy, other anticancer drugs, cancer recurrence between the first and the third year after the end of chemotherapy and follow-up < 3 years. Immunostaining of oxaliplatin transporters (OCT1, 2, 3, CTR1 and ATP7B) and Ki-67 was assessed in tumor samples. Results Retrospectively, 31 patients have been selected according to inclusion and exclusion criteria (15 responders and 16 non-responders). Before FOLFOX-4 regimen, OCT3 expression was significantly lower in responder patients compared to non-responders (p<0.001). According to multivariate analysis

  1. Altered transport of lindane caused by the retention of natural particles in saturated porous media

    NASA Astrophysics Data System (ADS)

    Ngueleu, Stéphane K.; Grathwohl, Peter; Cirpka, Olaf A.

    2014-07-01

    Attachment and straining of colloidal particles in porous media result in their reversible and irreversible retention. The retained particles may either increase the retention of hydrophobic pollutants by sorption onto the particles, or enhance pollutant transport when particles, loaded with the pollutants, are remobilized. The present study examines the effects of retained particles on the transport of the hydrophobic pesticide lindane (gamma-hexachlorocyclohexane) in saturated porous media. The lignite particles used have median diameters of about 3 μm, 1 μm, 0.8 μm, and 0.2 μm, respectively. Laboratory column experiments were analyzed by numerical modeling in order to identify and understand the processes involved in the transport of the particles and of lindane. Four scenarios were considered in which the solution containing lindane is injected either during or after the elution of the particles. The results show that lignite particles retained in a sandy porous medium alter the transport of the invading lindane. Particle retention was high in all scenarios and increased with increasing particle size. Remobilization of particles occurred due to a change in solution chemistry, and continuous particle detachment was observed over time. Numerical modeling of particle transport suggests that both reversible attachment and irreversible straining affected the transport of the particles. Lindane was retarded in all scenarios due to the strong particle retention in conjunction with the sorption of lindane onto the sand and onto retained particles, and the limited number of mobile particles carrying lindane. Moreover, it was found that intra-particle diffusion limited adsorption/desorption of lindane onto/from both limestone fragments of the sand and lignite particles. We assume that retention of lindane is reversible even though lindane recovery was incomplete over the duration of the experiments. The analysis of the effluent concentration suggests that retained

  2. Leukemia-Associated Mutations in Nucleophosmin Alter Recognition by CRM1: Molecular Basis of Aberrant Transport

    PubMed Central

    Arregi, Igor; Falces, Jorge; Olazabal-Herrero, Anne; Alonso-Mariño, Marián; Taneva, Stefka G.; Rodríguez, José A.; Urbaneja, María A.; Bañuelos, Sonia

    2015-01-01

    Nucleophosmin (NPM) is a nucleocytoplasmic shuttling protein, normally enriched in nucleoli, that performs several activities related to cell growth. NPM mutations are characteristic of a subtype of acute myeloid leukemia (AML), where mutant NPM seems to play an oncogenic role. AML-associated NPM mutants exhibit altered subcellular traffic, being aberrantly located in the cytoplasm of leukoblasts. Exacerbated export of AML variants of NPM is mediated by the nuclear export receptor CRM1, and due, in part, to a mutationally acquired novel nuclear export signal (NES). To gain insight on the molecular basis of NPM transport in physiological and pathological conditions, we have evaluated the export efficiency of NPM in cells, and present new data indicating that, in normal conditions, wild type NPM is weakly exported by CRM1. On the other hand, we have found that AML-associated NPM mutants efficiently form complexes with CRM1HA (a mutant CRM1 with higher affinity for NESs), and we have quantitatively analyzed CRM1HA interaction with the NES motifs of these mutants, using fluorescence anisotropy and isothermal titration calorimetry. We have observed that the affinity of CRM1HA for these NESs is similar, which may help to explain the transport properties of the mutants. We also describe NPM recognition by the import machinery. Our combined cellular and biophysical studies shed further light on the determinants of NPM traffic, and how it is dramatically altered by AML-related mutations. PMID:26091065

  3. Mouse organic solute transporter alpha deficiency alters FGF15 expression and bile acid metabolism.

    PubMed

    Lan, Tian; Rao, Anuradha; Haywood, Jamie; Kock, Nancy D; Dawson, Paul A

    2012-08-01

    Blocking intestinal bile acid (BA) absorption by inhibiting or inactivating the apical sodium-dependent BA transporter (Asbt) classically induces hepatic BA synthesis. In contrast, blocking intestinal BA absorption by inactivating the basolateral BA transporter, organic solute transporter alpha-beta (Ostα-Ostβ) is associated with an altered homeostatic response and decreased hepatic BA synthesis. The aim of this study was to determine the mechanisms underlying this phenotype, including the role of the farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15). BA and cholesterol metabolism, intestinal phenotype, expression of genes important for BA metabolism, and intestinal FGF15 expression were examined in wild type, Ostα(-/-), Fxr(-/-), and Ostα(-/-)Fxr(-/-) mice. Inactivation of Ostα was associated with decreases in hepatic cholesterol 7α-hydroxylase (Cyp7a1) expression, BA pool size, and intestinal cholesterol absorption. Ostα(-/-) mice exhibited significant small intestinal changes, including altered ileal villus morphology, and increases in intestinal length and mass. Total ileal FGF15 expression was elevated almost 20-fold in Ostα(-/-) mice as a result of increased villus epithelial cell number and ileocyte FGF15 protein expression. Ostα(-/-)Fxr(-/-) mice exhibited decreased ileal FGF15 expression, restoration of intestinal cholesterol absorption, and increases in hepatic Cyp7a1 expression, fecal BA excretion, and BA pool size. FXR deficiency did not reverse the intestinal morphological changes or compensatory decrease for ileal Asbt expression in Ostα(-/-) mice. These results indicate that signaling via FXR is required for the paradoxical repression of hepatic BA synthesis but not the complex intestinal adaptive changes in Ostα(-/-) mice. Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  4. Apple Polyphenol Phloretin Inhibits Colorectal Cancer Cell Growth via Inhibition of the Type 2 Glucose Transporter and Activation of p53-Mediated Signaling.

    PubMed

    Lin, Sheng-Tsai; Tu, Shih-Hsin; Yang, Po-Sheng; Hsu, Sung-Po; Lee, Wei-Hwa; Ho, Chi-Tang; Wu, Chih-Hsiung; Lai, Yu-Hsin; Chen, Ming-Yao; Chen, Li-Ching

    2016-09-14

    Glucose transporters (GLUTs) are required for glucose uptake in malignant cells, and they can be used as molecular targets for cancer therapy. An RT-PCR analysis was performed to investigate the mRNA levels of 14 subtypes of GLUTs in human colorectal cancer (COLO 205 and HT-29) and normal (FHC) cells. RT-PCR (n = 27) was used to assess the differences in paired tissue samples (tumor vs normal) isolated from colorectal cancer patients. GLUT2 was detected in all tested cells. The average GLUT2 mRNA level in 12 of 27 (44.4%) cases was 2.4-fold higher in tumor compared to normal tissues (*, p = 0.027). Higher GLUT2 mRNA expression was preferentially detected in advanced-stage tumors (stage 0 vs 3 = 16.38-fold, 95% CI = 9.22-26.54-fold; *, p = 0.029). The apple polyphenol phloretin (Ph) and siRNA methods were used to inhibit GLUT2 protein expression. Ph (0-100 μM, for 24 h) induced COLO 205 cell growth cycle arrest in a p53-dependent manner, which was confirmed by pretreatment of the cells with a p53-specific dominant negative expression vector. Hepatocyte nuclear factor 6 (HNF6), which was previously reported to be a transcription factor that activates GLUT2 and p53, was also induced by Ph (0-100 μM, for 24 h). The antitumor effect of Ph (25 mg/kg or DMSO twice a week for 6 weeks) was demonstrated in vivo using BALB/c nude mice bearing COLO 205 tumor xenografts. In conclusion, targeting GLUT2 could potentially suppress colorectal tumor cell invasiveness.

  5. Contribution of cyclin D1 (CCND1) and E-cadherin (CDH1) alterations to colorectal cancer susceptibility: a case-control study.

    PubMed

    Govatati, Suresh; Singamsetty, Gopi Krishna; Nallabelli, Nayudu; Malempati, Sravanthi; Rao, Pasupuleti Sreenivasa; Madamchetty, Venkata Kranthi Kumar; Govatati, Sowdamani; Kanapuram, Rudramadevi; Narayana, Nagesh; Bhanoori, Manjula; Kassetty, Kondaiah; Nallanchakravarthula, Varadacharyulu

    2014-12-01

    Cyclin D1 (CCND1) and E-cadherin (CDH1) are two important genes of the β-catenin/LEF pathway that is involved in tumorigenesis of various cancers including colorectal cancer (CRC). However, studies of the association between genetic variants of these two genes and CRC have shown conflicting results. We conducted a genetic association study in South Indian population (cases, 103; controls, 107) to assess the association of CCND1 870G/A and CDH1 -160C/A single nucleotide polymorphisms (SNPs) with CRC risk. Genotyping of SNPs was performed by PCR sequencing analysis. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pair-wise linkage disequilibrium (LD) were assessed by Haploview Software. In addition, to better understand the role of CCND1 and CDH1 in the pathophysiology of CRC, the expression pattern was evaluated in analogous tumor and adjacent normal tissues from 23 CRC patients by Western blot analysis. The frequencies of CCND1 870A/A (P = 0.045) genotype, CDH1 -160A allele (P = 0.042), and 870A/-160A haplotype (P = 0.002) were significantly higher in patients as compared with controls. Strong LD was observed between 870G/A and -160C/A SNPs in cases (D' = 0.76) as compared to controls (D' = 0.32). Furthermore, elevated CCND1 and diminished CDH1 expression was observed in tumor tissue as compared with analogous normal tissue of CRC patients. Interestingly, advanced-stage tumors showed wider expression alterations than in early-stage tumors. In conclusion, CCND1 870G/A and CDH1 -160C/A SNPs may modify the risk of CRC susceptibility in South Indian population. In addition, elevated CCND1 and diminished CDH1 expression appears to be useful prognostic markers for CRC.

  6. Altered DNA methylation of glucose transporter 1 and glucose transporter 4 in patients with major depressive disorder.

    PubMed

    Kahl, Kai G; Georgi, Karsten; Bleich, Stefan; Muschler, Marc; Hillemacher, Thomas; Hilfiker-Kleinert, Denise; Schweiger, Ulrich; Ding, Xiaoqi; Kotsiari, Alexandra; Frieling, Helge

    2016-05-01

    Alterations in brain glucose metabolism and in peripheral glucose metabolism have frequently been observed in major depressive disorder (MDD). The insulin independent glucose transporter 1 (GLUT1) plays a key role in brain metabolism while the insulin-dependent GLUT4 is the major glucose transporter for skeletal and cardiac muscle. We therefore examined methylation of GLUT1 and GLUT4 in fifty-two depressed inpatients and compared data to eighteen healthy comparison subjects. DNA methylation of the core promoter regions of GLUT1 and GLUT4 was assessed by bisulfite sequencing. Further factors determined were fasting glucose, cortisol, insulin, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). We found significantly increased methylation of the GLUT1 in depressed inpatients compared to healthy comparison subjects (CG). Further findings comprise increased concentrations of fasting cortisol, glucose, insulin, and increased IL-6 and TNF-α. After six weeks of inpatient treatment, significantly lower GLUT1 methylation was observed in remitted patients compared to non-remitters. GLUT4 methylation was not different between depressed patients and CG, and did not differ between remitted and non-remitted patients. Although preliminary we conclude from our results that the acute phase of major depressive disorder is associated with increased GLUT1 methylation and mild insulin resistance. The successful treatment of depression is associated with normalization of GLUT1 methylation in remitters, indicating that this condition may be reversible. Failure of normalization of GLUT1 methylation in non-remitters may point to a possible role of impeded brain glucose metabolism in the maintenance of MDD.

  7. Alcohol Cirrhosis Alters Nuclear Receptor and Drug Transporter Expression in Human Liver

    PubMed Central

    More, Vijay R.; Cheng, Qiuqiong; Donepudi, Ajay C.; Buckley, David B.; Lu, Zhenqiang James; Cherrington, Nathan J.

    2013-01-01

    Unsafe use of alcohol results in approximately 2.5 million deaths worldwide, with cirrhosis contributing to 16.6% of reported deaths. Serum insulin levels are often elevated in alcoholism and may result in diabetes, which is why alcoholic liver disease and diabetes often are present together. Because there is a sizable population with these diseases alone or in combination, the purpose of this study was to determine whether transporter expression in human liver is affected by alcoholic cirrhosis, diabetes, and alcoholic cirrhosis coexisting with diabetes. Transporters aid in hepatobiliary excretion of many drugs and toxic chemicals and can be determinants of drug-induced liver injury. Drug transporter expression and transcription factor–relative mRNA and protein expression in normal, diabetic, cirrhotic, and cirrhosis with diabetes human livers were quantified. Cirrhosis significantly increased ABCC4, 5, ABCG2, and solute carrier organic anion (SLCO) 2B1 mRNA expression and decreased SLCO1B3 mRNA expression in the liver. ABCC1, 3–5, and ABCG2 protein expression was also upregulated by alcoholic cirrhosis. ABCC3-5 and ABCG2 protein expression was also upregulated in diabetic cirrhosis. Cirrhosis increased nuclear factor E2–related factor 2 mRNA expression, whereas it decreased pregnane-X-receptor and farnesoid-X-receptor mRNA expression in comparison with normal livers. Hierarchical cluster analysis indicated that expressions of ABCC2, 3, and 6; SLCO1B1 and 1B3; and ABCC4 and 5 were more closely related in the livers from this cohort. Overall, alcoholic cirrhosis altered transporter expression in human liver. PMID:23462698

  8. Alcohol cirrhosis alters nuclear receptor and drug transporter expression in human liver.

    PubMed

    More, Vijay R; Cheng, Qiuqiong; Donepudi, Ajay C; Buckley, David B; Lu, Zhenqiang James; Cherrington, Nathan J; Slitt, Angela L

    2013-05-01

    Unsafe use of alcohol results in approximately 2.5 million deaths worldwide, with cirrhosis contributing to 16.6% of reported deaths. Serum insulin levels are often elevated in alcoholism and may result in diabetes, which is why alcoholic liver disease and diabetes often are present together. Because there is a sizable population with these diseases alone or in combination, the purpose of this study was to determine whether transporter expression in human liver is affected by alcoholic cirrhosis, diabetes, and alcoholic cirrhosis coexisting with diabetes. Transporters aid in hepatobiliary excretion of many drugs and toxic chemicals and can be determinants of drug-induced liver injury. Drug transporter expression and transcription factor-relative mRNA and protein expression in normal, diabetic, cirrhotic, and cirrhosis with diabetes human livers were quantified. Cirrhosis significantly increased ABCC4, 5, ABCG2, and solute carrier organic anion (SLCO) 2B1 mRNA expression and decreased SLCO1B3 mRNA expression in the liver. ABCC1, 3-5, and ABCG2 protein expression was also upregulated by alcoholic cirrhosis. ABCC3-5 and ABCG2 protein expression was also upregulated in diabetic cirrhosis. Cirrhosis increased nuclear factor E2-related factor 2 mRNA expression, whereas it decreased pregnane-X-receptor and farnesoid-X-receptor mRNA expression in comparison with normal livers. Hierarchical cluster analysis indicated that expressions of ABCC2, 3, and 6; SLCO1B1 and 1B3; and ABCC4 and 5 were more closely related in the livers from this cohort. Overall, alcoholic cirrhosis altered transporter expression in human liver.

  9. Genetic and chemical reductions in protein phosphatase activity alter auxin transport, gravity response, and lateral root growth

    NASA Technical Reports Server (NTRS)

    Rashotte, A. M.; DeLong, A.; Muday, G. K.; Brown, C. S. (Principal Investigator)

    2001-01-01

    Auxin transport is required for important growth and developmental processes in plants, including gravity response and lateral root growth. Several lines of evidence suggest that reversible protein phosphorylation regulates auxin transport. Arabidopsis rcn1 mutant seedlings exhibit reduced protein phosphatase 2A activity and defects in differential cell elongation. Here we report that reduced phosphatase activity alters auxin transport and dependent physiological processes in the seedling root. Root basipetal transport was increased in rcn1 or phosphatase inhibitor-treated seedlings but showed normal sensitivity to the auxin transport inhibitor naphthylphthalamic acid (NPA). Phosphatase inhibition reduced root gravity response and delayed the establishment of differential auxin-induced gene expression across a gravity-stimulated root tip. An NPA treatment that reduced basipetal transport in rcn1 and cantharidin-treated wild-type plants also restored a normal gravity response and asymmetric auxin-induced gene expression, indicating that increased basipetal auxin transport impedes gravitropism. Increased auxin transport in rcn1 or phosphatase inhibitor-treated seedlings did not require the AGR1/EIR1/PIN2/WAV6 or AUX1 gene products. In contrast to basipetal transport, root acropetal transport was normal in phosphatase-inhibited seedlings in the absence of NPA, although it showed reduced NPA sensitivity. Lateral root growth also exhibited reduced NPA sensitivity in rcn1 seedlings, consistent with acropetal transport controlling lateral root growth. These results support the role of protein phosphorylation in regulating auxin transport and suggest that the acropetal and basipetal auxin transport streams are differentially regulated.

  10. Genetic and chemical reductions in protein phosphatase activity alter auxin transport, gravity response, and lateral root growth

    NASA Technical Reports Server (NTRS)

    Rashotte, A. M.; DeLong, A.; Muday, G. K.; Brown, C. S. (Principal Investigator)

    2001-01-01

    Auxin transport is required for important growth and developmental processes in plants, including gravity response and lateral root growth. Several lines of evidence suggest that reversible protein phosphorylation regulates auxin transport. Arabidopsis rcn1 mutant seedlings exhibit reduced protein phosphatase 2A activity and defects in differential cell elongation. Here we report that reduced phosphatase activity alters auxin transport and dependent physiological processes in the seedling root. Root basipetal transport was increased in rcn1 or phosphatase inhibitor-treated seedlings but showed normal sensitivity to the auxin transport inhibitor naphthylphthalamic acid (NPA). Phosphatase inhibition reduced root gravity response and delayed the establishment of differential auxin-induced gene expression across a gravity-stimulated root tip. An NPA treatment that reduced basipetal transport in rcn1 and cantharidin-treated wild-type plants also restored a normal gravity response and asymmetric auxin-induced gene expression, indicating that increased basipetal auxin transport impedes gravitropism. Increased auxin transport in rcn1 or phosphatase inhibitor-treated seedlings did not require the AGR1/EIR1/PIN2/WAV6 or AUX1 gene products. In contrast to basipetal transport, root acropetal transport was normal in phosphatase-inhibited seedlings in the absence of NPA, although it showed reduced NPA sensitivity. Lateral root growth also exhibited reduced NPA sensitivity in rcn1 seedlings, consistent with acropetal transport controlling lateral root growth. These results support the role of protein phosphorylation in regulating auxin transport and suggest that the acropetal and basipetal auxin transport streams are differentially regulated.

  11. Sources, transport and alterations of metal compounds: an overview. I. Arsenic, beryllium, cadmium, chromium, and nickel.

    PubMed Central

    Fishbein, L

    1981-01-01

    An overview is presented of the current state of knowledge of the salient aspects of the sources, transport, and alterations of arsenic, beryllium, cadmium, chromium, and nickel. This information is considered vital for a better assessment of the scope of potential human hazard to these ubiquitous toxicants and their compounds. Stress is focused on both natural and industrial activities, particularly on the latter's projected trends. Increasing use patterns per se of most of these metals, as well as aspects of waste disposal and the anticipated increased combustion of fossil fuels for power generation and space heating (particularly in the United States), are major causes of potential health concern. Additionally, attention is drawn to the need for increased research to fill the gaps in our knowledge in these vital areas, all in the hope of permitting a more facile identification and quantification of the potential hazard to exposure to these agents. PMID:7023934

  12. Obesity and colorectal cancer.

    PubMed

    Aleksandrova, Krasimira; Nimptsch, Katharina; Pischon, Tobias

    2013-01-01

    This review outlines the association of obesity with risk of colorectal cancer and the potential underlying mechanisms from an epidemiological perspective. Current research indicates that there is a moderate but consistently reported association between general obesity (as determined by BMI) and colorectal cancer incidence and mortality. The relative risk associated with obesity is higher for cancer of the colon than for cancer of the rectum and it is higher in men than in women. By contrast, abdominal adiposity (as determined by waist circumference or waist-to-hip ratio) is similarly strongly associated with colon cancer in men and women, suggesting that abdominal adiposity is a more important risk factor for colon cancer than general adiposity, at least in women. Putative mechanisms that may account for the link between adiposity and colorectal cancer risk include hyperinsulinemia, insulin resistance, inflammation, altered immune response, oxidative stress, as well as disturbances in insulin-like growth factors, adipokines, and sex steroids. Understanding the link between obesity and colorectal cancer may pave the way for targeted prevention of colorectal cancer morbidity and mortality.

  13. Statins alter the hepatobiliary transport of unconjugated and conjugated bilirubin in sandwich-cultured rat hepatocytes.

    PubMed

    Szabó, Mónika; Veres, Zsuzsa; Bátai-Konczos, Attila; Kékesi, Orsolya; Kis, Emese; Szabó, Kitti; Jemnitz, Katalin

    2014-09-01

    Several studies have reported that statins occasionally cause impairment of liver functions characterized by elevated serum bilirubin levels, which might be due to altered function of the multidrug resistance-associated proteins (Mrp2/3). We aimed to study the modulation of the hepatobiliary transport of bilirubin by four statin derivatives, atorvastatin, fluvastatin, pravastatin, and rosuvastatin in sandwich-cultured rat hepatocytes. All statins except pravastatin significantly inhibited the uptake of bilirubin. The biliary efflux of bilirubin conjugates was increased by pravastatin and rosuvastatin concentration dependently. Rosuvastatin stimulated not only the Mrp2 mediated biliary, but the Mrp3 mediated sinusoidal elimination, resulting in decreased intracellular bilirubin accumulation. The significantly induced Mrp2/3 protein levels (ranging from 1.5 to 1.8-fold) accounted for the elevated efflux. Cell polarization, the formation of biliary network was also significantly increased by fluvastatin, pravastatin and rosuvastatin (151%, 216% and 275% of the control, respectively). The simultaneous inhibition of the uptake and the stimulation of the sinusoidal and canalicular elimination may explain, at least in part, the clinical observation of elevated serum bilirubin levels. In conclusion, our results suggest that in spite of the elevated serum bilirubin levels, the altered Mrp2 and Mrp3 functions by statins is probably not associated with hepatotoxic effects.

  14. Conformational Exchange in a Membrane Transport Protein Is Altered in Protein Crystals

    SciTech Connect

    D Freed; P Horanyi; M Wiener; D Cafiso

    2011-12-31

    Successful macromolecular crystallography requires solution conditions that may alter the conformational sampling of a macromolecule. Here, site-directed spin labeling is used to examine a conformational equilibrium within BtuB, the Escherichia coli outer membrane transporter for vitamin B{sub 12}. Electron paramagnetic resonance (EPR) spectra from a spin label placed within the N-terminal energy coupling motif (Ton box) of BtuB indicate that this segment is in equilibrium between folded and unfolded forms. In bilayers, substrate binding shifts this equilibrium toward the unfolded form; however, EPR spectra from this same spin-labeled mutant indicate that this unfolding transition is blocked in protein crystals. Moreover, crystal structures of this spin-labeled mutant are consistent with the EPR result. When the free energy difference between substates is estimated from the EPR spectra, the crystal environment is found to alter this energy by 3 kcal/mol when compared to the bilayer state. Approximately half of this energy change is due to solutes or osmolytes in the crystallization buffer, and the remainder is contributed by the crystal lattice. These data provide a quantitative measure of how a conformational equilibrium in BtuB is modified in the crystal environment, and suggest that more-compact, less-hydrated substates will be favored in protein crystals.

  15. Conformational Exchange in a Membrane Transport Protein Is Altered in Protein Crystals

    SciTech Connect

    Freed, Daniel M.; Horanyi, Peter S.; Wiener, Michael C.; Cafiso, David S.

    2010-09-27

    Successful macromolecular crystallography requires solution conditions that may alter the conformational sampling of a macromolecule. Here, site-directed spin labeling is used to examine a conformational equilibrium within BtuB, the Escherichia coli outer membrane transporter for vitamin B{sub 12}. Electron paramagnetic resonance (EPR) spectra from a spin label placed within the N-terminal energy coupling motif (Ton box) of BtuB indicate that this segment is in equilibrium between folded and unfolded forms. In bilayers, substrate binding shifts this equilibrium toward the unfolded form; however, EPR spectra from this same spin-labeled mutant indicate that this unfolding transition is blocked in protein crystals. Moreover, crystal structures of this spin-labeled mutant are consistent with the EPR result. When the free energy difference between substates is estimated from the EPR spectra, the crystal environment is found to alter this energy by 3 kcal/mol when compared to the bilayer state. Approximately half of this energy change is due to solutes or osmolytes in the crystallization buffer, and the remainder is contributed by the crystal lattice. These data provide a quantitative measure of how a conformational equilibrium in BtuB is modified in the crystal environment, and suggest that more-compact, less-hydrated substates will be favored in protein crystals.

  16. Clopidogrel attenuates lithium-induced alterations in renal water and sodium channels/transporters in mice.

    PubMed

    Zhang, Yue; Peti-Peterdi, János; Heiney, Kristina M; Riquier-Brison, Anne; Carlson, Noel G; Müller, Christa E; Ecelbarger, Carolyn M; Kishore, Bellamkonda K

    2015-12-01

    Lithium (Li) administration causes deranged expression and function of renal aquaporins and sodium channels/transporters resulting in nephrogenic diabetes insipidus (NDI). Extracellular nucleotides (ATP/ADP/UTP), via P2 receptors, regulate these transport functions. We tested whether clopidogrel bisulfate (CLPD), an antagonist of ADP-activated P2Y(12) receptor, would affect Li-induced alterations in renal aquaporins and sodium channels/transporters. Adult mice were treated for 14 days with CLPD and/or Li and euthanized. Urine and kidneys were collected for analysis. When administered with Li, CLPD ameliorated polyuria, attenuated the rise in urine prostaglandin E2 (PGE2), and resulted in significantly higher urinary arginine vasopressin (AVP) and aldosterone levels as compared to Li treatment alone. However, urine sodium excretion remained elevated. Semi-quantitative immunoblotting revealed that CLPD alone increased renal aquaporin 2 (AQP2), Na-K-2Cl cotransporter (NKCC2), Na-Cl cotransporter (NCC), and the subunits of the epithelial Na channel (ENaC) in medulla by 25-130 %. When combined with Li, CLPD prevented downregulation of AQP2, Na-K-ATPase, and NKCC2 but was less effective against downregulation of cortical α- or γ-ENaC (70 kDa band). Thus, CLPD primarily attenuated Li-induced downregulation of proteins involved in water conservation (AVP-sensitive), with modest effects on aldosterone-sensitive proteins potentially explaining sustained natriuresis. Confocal immunofluorescence microscopy revealed strong labeling for P2Y(12)-R in proximal tubule brush border and blood vessels in the cortex and less intense labeling in medullary thick ascending limb and the collecting ducts. Therefore, there is the potential for CLPD to be directly acting at the tubule sites to mediate these effects. In conclusion, P2Y(12)-R may represent a novel therapeutic target for Li-induced NDI.

  17. Molecular mechanisms of altered bile acid homeostasis in organic solute transporter-alpha knockout mice.

    PubMed

    Lan, Tian; Haywood, Jamie; Rao, Anuradha; Dawson, Paul A

    2011-01-01

    Mutations in the apical sodium-dependent bile acid transporter (SLC10A2) block intestinal bile acid absorption, resulting in a compensatory increase in hepatic bile acid synthesis. Inactivation of the basolateral membrane bile acid transporter (OSTα-OSTβ) also impairs intestinal bile acid absorption, but hepatic bile acid synthesis was paradoxically repressed. We hypothesized that the altered bile acid homeostasis resulted from ileal trapping of bile acids that act via the farnesoid X receptor (FXR) to induce overexpression of FGF15. To test this hypothesis, we investigated whether blocking FXR signaling would reverse the bile acid synthesis phenotype in Ostα null mice. The corresponding null mice were crossbred to generate OstαFxr double-null mice. All experiments compared wild-type, Ostα, Fxr and OstαFxr null littermates. Analysis of the in vivo phenotype included measurements of bile acid fecal excretion, pool size and composition. Hepatic and intestinal gene and protein expression were also examined. OstαFxr null mice exhibited increased bile acid fecal excretion and pool size, and decreased bile acid pool hydrophobicity, as compared with Ostα null mice. Inactivation of FXR reversed the increase in ileal total FGF15 expression, which was associated with a significant increase in hepatic Cyp7a1 expression. Inactivation of FXR largely unmasked the bile acid malabsorption phenotype and corrected the bile acid homeostasis defect in Ostα null mice, suggesting that inappropriate activation of the FXR-FGF15-FGFR4 pathway partially underlies this phenotype. Intestinal morphological changes and reduced apical sodium-dependent bile acid transporter expression were maintained in Ostα(-/-)Fxr(-/-) mice, indicating that FXR is not required for these adaptive responses. Copyright © 2011 S. Karger AG, Basel.

  18. Computational Fluid Dynamics modeling of contrast transport in basilar aneurysms following flow-altering surgeries.

    PubMed

    Vali, Alireza; Abla, Adib A; Lawton, Michael T; Saloner, David; Rayz, Vitaliy L

    2017-01-04

    In vivo measurement of blood velocity fields and flow descriptors remains challenging due to image artifacts and limited resolution of current imaging methods; however, in vivo imaging data can be used to inform and validate patient-specific computational fluid dynamics (CFD) models. Image-based CFD can be particularly useful for planning surgical interventions in complicated cases such as fusiform aneurysms of the basilar artery, where it is crucial to alter pathological hemodynamics while preserving flow to the distal vasculature. In this study, patient-specific CFD modeling was conducted for two basilar aneurysm patients considered for surgical treatment. In addition to velocity fields, transport of contrast agent was simulated for the preoperative and postoperative conditions using two approaches. The transport of a virtual contrast passively following the flow streamlines was simulated to predict post-surgical flow regions prone to thrombus deposition. In addition, the transport of a mixture of blood with an iodine-based contrast agent was modeled to compare and verify the CFD results with X-ray angiograms. The CFD-predicted patterns of contrast flow were qualitatively compared to in vivo X-ray angiograms acquired before and after the intervention. The results suggest that the mixture modeling approach, accounting for the flow rates and properties of the contrast injection, is in better agreement with the X-ray angiography data. The virtual contrast modeling assessed the residence time based on flow patterns unaffected by the injection procedure, which makes the virtual contrast modeling approach better suited for prediction of thrombus deposition, which is not limited to the peri-procedural state.

  19. Altered expression of regulators of the cortical chloride transporters NKCC1 and KCC2 in schizophrenia

    PubMed Central

    Arion, Dominique; Lewis, David A.

    2010-01-01

    Context Disturbances in markers of cortical GABA neurotransmission are a common finding in schizophrenia. The nature of GABA neurotransmission (hyperpolarizing or depolarizing) depends on the local intracellular Cl− concentration. In the central nervous system, the intracellular Cl− level is determined by the activity of two cation-chloride transporters, NKCC1 and KCC2. The activities of these transporters are in turn regulated by a network of serine-threonine kinases that includes OXSR1, STK39 and the WNK kinases WNK1, 3 and 4. Objective To compare the levels of NKCC1, KCC2, OXSR1, STK39, WNK1, WNK3 and WNK4 transcripts in prefrontal cortex area 9 between schizophrenia and normal comparison subjects. Design Real-time qPCR technique was used to measure transcript levels in prefrontal cortex. Setting Human brain specimens were obtained from autopsies conducted at the Allegheny County Medical Examiner’s Office, Pittsburgh, PA. Participants Postmortem brain specimens from 42 subjects with schizophrenia and 42 matched normal comparison subjects. Brain specimens from 18 macaque monkeys chronically exposed to haloperidol, olanzapine, or sham. Main outcome measures Relative expression levels for NKCC1, KCC2, OXSR1, STK39, WNK1, WNK3 and WNK4 transcripts compared to the mean expression level of three housekeeping transcripts. Results OXSR1 and WNK3 transcripts were substantially over-expressed in schizophrenia relative to comparison subjects. In contrast, NKCC1, KCC2, STK39, WNK1 and WNK4 transcript levels did not differ between subject groups. OXSR1 and WNK3 transcript expression levels were not changed in antipsychotic-exposed monkeys and were not affected by potential confounding factors in the subjects with schizophrenia. Conclusions In schizophrenia, increased expression levels, and possibly increased kinase activities, of OXSR1 and WNK3 may shift the balance of chloride transport by NKCC1 and KCC2 and alter the nature of GABA neurotransmission in the prefrontal

  20. DNA copy number alterations, gene expression changes and disease-free survival in patients with colorectal cancer: a 10 year follow-up.

    PubMed

    Bigagli, Elisabetta; De Filippo, Carlotta; Castagnini, Cinzia; Toti, Simona; Acquadro, Francesco; Giudici, Francesco; Fazi, Marilena; Dolara, Piero; Messerini, Luca; Tonelli, Francesco; Luceri, Cristina

    2016-12-01

    DNA copy number alterations (CNAs) and gene expression changes have amply been encountered in colorectal cancers (CRCs), but the extent at which CNAs affect gene expression, as well as their relevance for tumor development, are still poorly defined. Here we aimed at assessing the clinical relevance of these parameters in a 10 year follow-up study. Tumors and normal adjacent colon mucosa, obtained at primary surgery from 21 CRC patients, were subjected to (i) high-resolution array CGH (a-CGH) for the detection of CNAs and (ii) microarray-based transcriptome profiling for the detection of gene expression (GE) changes. Correlations between these genomic and transcriptomic changes and their associations with clinical and histopathological parameters were assessed with the aim to identify molecular signatures associated with disease-free survival of the CRC patients during a 10 year follow-up. DNA copy number gains were frequently detected in chromosomes 7, 8q, 13, 19, 20q and X, whereas DNA copy number losses were frequently detected in chromosomes 1p, 4, 8p, 15, 17p, 18, 19 and 22q. None of these alterations were observed in all samples. In addition, we found that 2,498 genes were up- and that 1,094 genes were down-regulated in the tumor samples compared to their corresponding normal mucosa (p < 0.01). The expression of 65 genes was found to be significantly associated with prognosis (p < 0.01). Specifically, we found that up-regulation of the IL17RA, IGF2BP2 and ABCC2 genes, and of genes acting in the mTOR and cytokine receptor pathways, were strongly associated with a poor survival. Subsequent integrated analyses revealed that increased expression levels of the MMP9, BMP7, UBE2C, I-CAM, NOTCH3, NOTCH1, PTGES2, HMGB1 and ERBB3 genes were associated with copy number gains, whereas decreased expression levels of the MUC1, E2F2, HRAS and SIRT3 genes were associated with copy number losses. Pathways related to cell cycle progression, eicosanoid metabolism, and

  1. Serum 25-hydroxyvitamin D, vitamin D binding protein, and risk of colorectal cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

    PubMed Central

    Weinstein, Stephanie J.; Purdue, Mark P.; Smith-Warner, Stephanie A.; Mondul, Alison M.; Black, Amanda; Ahn, Jiyoung; Huang, Wen-Yi; Horst, Ronald L.; Kopp, William; Rager, Helen; Ziegler, Regina G.; Albanes, Demetrius

    2014-01-01

    The potential role of vitamin D in cancer prevention has generated substantial interest, and laboratory experiments indicate several anti-cancer properties for vitamin D compounds. Prospective studies of circulating 25-hydroxyvitamin D [25(OH)D], the accepted biomarker of vitamin D status, suggest an inverse association with colorectal cancer risk, but with some inconsistencies. Furthermore, the direct or indirect impact of the key transport protein, vitamin D binding protein (DBP), has not been examined. We conducted a prospective study of serum 25(OH)D and DBP concentrations and colorectal cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, based on 476 colorectal cancer cases and 476 controls, matched on age, sex, race, and date of serum collection. All subjects underwent sigmoidoscopic screening at baseline and once during follow-up. Conditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Circulating 25(OH)D was inversely associated with colorectal cancer (OR=0.60, 95% CI 0.38-0.94 for highest versus lowest quintile, p-trend 0.01). Adjusting for recognized colorectal cancer risk factors and accounting for seasonal vitamin D variation did not alter the findings. Neither circulating DBP nor the 25(OH)D:DBP molar ratio, a proxy for free circulating 25(OH)D, was associated with risk (OR=0.82, 95% CI 0.54-1.26, and OR=0.79, 95% CI 0.52-1.21, respectively), and DBP did not modify the 25(OH)D association. The current study eliminated confounding by colorectal cancer screening behavior, and supports an association between higher vitamin D status and substantially lower colorectal cancer risk, but does not indicate a direct or modifying role for DBP. PMID:25156182

  2. Serum 25-hydroxyvitamin D, vitamin D binding protein and risk of colorectal cancer in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

    PubMed

    Weinstein, Stephanie J; Purdue, Mark P; Smith-Warner, Stephanie A; Mondul, Alison M; Black, Amanda; Ahn, Jiyoung; Huang, Wen-Yi; Horst, Ronald L; Kopp, William; Rager, Helen; Ziegler, Regina G; Albanes, Demetrius

    2015-03-15

    The potential role of vitamin D in cancer prevention has generated substantial interest, and laboratory experiments indicate several anti-cancer properties for vitamin D compounds. Prospective studies of circulating 25-hydroxyvitamin D [25(OH)D], the accepted biomarker of vitamin D status, suggest an inverse association with colorectal cancer risk, but with some inconsistencies. Furthermore, the direct or indirect impact of the key transport protein, vitamin D binding protein (DBP), has not been examined. We conducted a prospective study of serum 25(OH)D and DBP concentrations and colorectal cancer risk in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial, based on 476 colorectal cancer cases and 476 controls, matched on age, sex, race and date of serum collection. All subjects underwent sigmoidoscopic screening at baseline and once during follow-up. Conditional logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Circulating 25(OH)D was inversely associated with colorectal cancer (OR = 0.60, 95% CI 0.38-0.94 for highest versus lowest quintile, p trend 0.01). Adjusting for recognized colorectal cancer risk factors and accounting for seasonal vitamin D variation did not alter the findings. Neither circulating DBP nor the 25(OH)D:DBP molar ratio, a proxy for free circulating 25(OH)D, was associated with risk (OR = 0.82, 95% CI 0.54-1.26, and OR = 0.79, 95% CI 0.52-1.21, respectively), and DBP did not modify the 25(OH)D association. The current study eliminated confounding by colorectal cancer screening behavior, and supports an association between higher vitamin D status and substantially lower colorectal cancer risk, but does not indicate a direct or modifying role for DBP. © 2014 UICC.

  3. Cocaine Self-Administration Produces Long-Lasting Alterations in Dopamine Transporter Responses to Cocaine

    PubMed Central

    Siciliano, Cody A.; Fordahl, Steve C.

    2016-01-01

    , the dopamine transporter (DAT). Preclinical literature has shown that reduced cocaine potency at the DAT increases cocaine taking, highlighting the key role of tolerance in addiction. Addiction is characterized by cycles of abstinence, often for many months, followed by relapse, making it important to determine possible interactions between abstinence and subsequent drug re-exposure. Using a rodent model of cocaine abuse, we found long-lasting, possibly permanent, cocaine-induced alterations to the DAT, whereby cocaine tolerance is reinstated by minimal drug exposure, even after recovery of DAT function over prolonged abstinence periods. PMID:27466327

  4. Cronobacter sakazakii infection alters serotonin transporter and improved fear memory retention in the rat

    PubMed Central

    Sivamaruthi, Bhagavathi S.; Madhumita, Rajkumar; Balamurugan, Krishnaswamy; Rajan, Koilmani E.

    2015-01-01

    It is well established that Cronobacter sakazakii infection cause septicemia, necrotizing enterocolitis and meningitis. In the present study, we tested whether the C. sakazakii infection alter the learning and memory through serotonin transporter (SERT). To investigate the possible effect on SERT, on postnatal day-15 (PND-15), wistar rat pups were administered with single dose of C. sakazakii culture (infected group; 107 CFU) or 100 μL of Luria-Bertani broth (medium control) or without any treatment (naïve control). All the individuals were subjected to passive avoidance test on PND-30 to test their fear memory. We show that single dose of C. sakazakii infection improved fear memory retention. Subsequently, we show that C. sakazakii infection induced the activation of toll-like receptor-3 and heat-shock proteins-90 (Hsp-90). On the other hand, level of serotonin (5-hydroxytryptamine) and SERT protein was down-regulated. Furthermore, we show that C. sakazakii infection up-regulate microRNA-16 (miR-16) expression. The observed results highlight that C. sakazakii infections was responsible for improved fear memory retention and may have reduced the level of SERT protein, which is possibly associated with the interaction of up-regulated Hsp-90 with SERT protein or miR-16 with SERT mRNA. Taken together, observed results suggest that C. sakazakii infection alter the fear memory possibly through SERT. Hence, this model may be effective to test the C. sakazakii infection induced changes in synaptic plasticity through SERT and effect of other pharmacological agents against pathogen induced memory disorder. PMID:26388777

  5. The alteration of serine transporter activity in a cell line model of amyotrophic lateral sclerosis (ALS).

    PubMed

    Lee, Na-Young; Kim, Yunha; Ryu, Hoon; Kang, Young-Sook

    2017-01-29

    The alteration of d-serine levels is associated with the pathogenesis of sporadic ALS and mutant SOD1 (G93A) animal model of ALS. However, the exact mechanism of d-serine transport is not known in ALS. To better understand the distribution of d-serine in ALS, we determined the activity and the expression of serine transporter in a motor neuronal cell line model of ALS (NSC-34/hSOD1(G93A) cells). The uptake of [(3)H]d-serine was significantly lower in NSC-34/hSOD1(G93A) cells than in control NSC-34 and NSC-34/hSOD1(wt) cells. In contrast, the uptake of [(3)H]l-serine, precursor of d-serine, was markedly increased in NSC-34/hSOD1(G93A) cells compared to control NSC-34 and NSC-34/hSOD1(wt) cells. Both [(3)H]d-serine and [(3)H]l-serine uptake were saturable in these cells. The estimated Michaelis-Menten constant, Km, for d-serine uptakes was higher in NSC-34/hSOD1(G93A) cells than in NSC-34/hSOD1(wt) cells while the Km for l-serine uptake was 2 fold lower in NSC-34/hSOD1(G93A) cells than in control cells. [(3)H]d-serine and [(3)H]l-serine uptakes took place in a Na(+)-dependent manner, and both uptakes were significantly inhibited by system ASC (alanine-serine-cysteine) substrates. As a result of small interfering RNA experiments, we found that ASCT2 (SLC1A5) and ASCT1 (SLC1A4) are involved in [(3)H]d-serine and [(3)H]l-serine uptake in NSC-34/hSOD1(G93A) cells, respectively. The level of SLC1A4 mRNA was significantly increased in NSC-34/hSOD1(G93A) compared to NSC-34 and NSC-34/hSOD1(wt) cells. In contrast, the level of SLC7A10 mRNA was relatively lower in NSC-34/hSOD1(G93A) cells than the control cells. Together, these data suggest that the pathological alteration of d- and l-serine uptakes in ALS is driven by the affinity change of d-and l-serine uptake system.

  6. Methylmercury induces oxidative injury, alterations in permeability and glutamine transport in cultured astrocytes

    PubMed Central

    Yin, Zhaobao; Milatovic, Dejan; Aschner, Judy L.; Syversen, Tore; Rocha, Joao B.T.; Souza, Diogo O.; Sidoryk, Marta; Albrecht, Jan; Aschner, Michael

    2007-01-01

    The neurotoxicity of high levels of methylmercury (MeHg) is well established both in humans and experimental animals. Astrocytes accumulate MeHg and play a prominent role in mediating MeHg toxicity in the central nervous system (CNS). Although the precise mechanisms of MeHg neurotoxicity are ill-defined, oxidative stress and altered mitochondrial and cell membrane permeability appear to be critical factors in its pathogenesis. The present study examined the effects of MeHg treatment on oxidative injury, mitochondrial inner membrane potential, glutamine uptake and expression of glutamine transporters in primary astrocyte cultures. MeHg caused a significant increase in F2-isoprostanes (F2-IsoPs), lipid peroxidation biomarkers of oxidative damage, in astrocyte cultures treated with 5 or 10 μ M MeHg for 1 or 6 hours. Consistent with this observation, MeHg induced a concentration-dependant reduction in the inner mitochondrial membrane potential (ΔΨm), as assessed by the potentiometric dye, tetramethylrhodamine ethyl ester (TMRE). Our results demonstrate that ΔΨm is a very sensitive endpoint for MeHg toxicity, since significant reductions were observed after only 1 h exposure to concentrations of MeHg as low as 1 μ M. MeHg pretreatment (1, 5 and 10 μ M) for 30 min also inhibited the net uptake of glutamine (3H-glutamine) measured at 1 min and 5 min. Expression of the mRNA coding the glutamine transporters, SNAT3/SN1 and ASCT2, was inhibited only at the highest (10 μ M) MeHg concentration, suggesting that the reduction in glutamine uptake observed after 30 min treatment with lower concentrations of MeHg (1 and 5 μ M) was not due to inhibition of transcription. Taken together, these studies demonstrate that MeHg exposure is associated with increased mitochondrial membrane permeability, alterations in glutamine/glutamate cycling, increased ROS formation and consequent oxidative injury. Ultimately, MeHg initiates multiple additive or synergistic disruptive

  7. Mouse model of foreign body reaction that alters the submesothelium and transperitoneal transport.

    PubMed

    Peters, Toni; Potter, Rebecca; Li, Xiarong; He, Zhi; Hoskins, Glenn; Flessner, Michael F

    2011-01-01

    To address the hypothesis that sterile intraperitoneal (ip) catheters alone promote a progressive foreign body reaction (FBR), silicone catheters were surgically implanted in C57BL mice. Controls (CON) underwent sham operations. After 1-5 wk (E1-E5 for catheter-bearing mice), catheters were recovered, and the adherent cell layer (ACL) was separated and cultured to demonstrate sterility. Transperitoneal transport experiments were performed to determine the mass transfer coefficients of mannitol (MTCM) and albumin (MTCA) and the osmotic filtration flux (Josm). After euthanasia, tissue samples were analyzed for submesothelial thickness, angiogenesis, and cytokine immunohistochemistry (IHC). Progressive increases with time were observed in submesothelial thickness (μm: CON, 18.8±12.3; E1, 46.1±20.0; E2, 72.0±17.9; E4, 97.3±20.0; E5, 131.7±10.3; P<0.003), angiogenesis (no. of vessels/mm of peritoneum: CON, 10.7±9.4; E1, 15.4±15.6; E2, 27.0±14.0; E4, 39.8±15.7; E5, 90.1±8.1; P<0.0003), MTCA (6.5±1.5×10(-5) cm/min, mean CON; 18.0±1.1×10(-5) cm/min, mean E1-E5, P<0.0001), Josm (0.0013±0.0001 cm/min, mean CON; 0.0017±0.0001 cm/min, mean E1-E5, P<0.01). No significant differences were found for MTCM. IHC demonstrated strong staining for all treated animals and correlated with the ACL. This mouse model demonstrates that ip silicone catheters result in progressive FBR, altering the submesothelial anatomy and transperitoneal transport, and will form the basis for mechanistic studies in genetically-altered animals.

  8. Temperature alters solute transport in growth plate cartilage measured by in vivo multiphoton microscopy

    PubMed Central

    Serrat, Maria A.; Williams, Rebecca M.; Farnum, Cornelia E.

    2009-01-01

    Solute delivery to avascular cartilaginous plates is critical to bone elongation, and impaired transport of nutrients and growth factors in cartilage matrix could underlie many skeletal abnormalities. Advances in imaging technology have revolutionized our ability to visualize growth plates in vivo, but quantitative methods are still needed. We developed analytical standards for measuring solute delivery, defined by amount and rate of intravenous tracer entry, in murine growth plates using multiphoton microscopy. We employed an acute temperature model because of its well-established impact on bone circulation and tested the hypothesis that solute delivery changes positively with limb temperature when body core and respiration are held constant (36°C, 120 breaths/min). Tibial growth plates were surgically exposed in anesthetized 5-wk-old mice, and their hindlimbs were immersed in warm (36°C) or cool (23°C) saline (n = 6/group). After 30 min of thermal equilibration, we administered an intracardiac injection of fluorescein (50 μl, 0.5%) and captured sequentially timed growth plate images spanning 10 min at standardized depth. Absolute growth plate fluorescence was normalized to vascular concentrations for interanimal comparisons. As predicted, more fluorescein infiltrated growth plates at 36°C, with standardized values nearly double those at 23°C. Changing initial limb temperature did not alter baseline values, suggesting a sustained response period. These data validate the sensitivity of our system and have relevance to strategies for enhancing localized delivery of therapeutic agents to growth plates of children. Applications of this technique include assessment of solute transport in models of growth plate dysfunction, particularly chondrodysplasias with matrix irregularities. PMID:19372302

  9. TNFα Transport Induced by Dynamic Loading Alters Biomechanics of Intact Intervertebral Discs

    PubMed Central

    Walter, Benjamin A.; Likhitpanichkul, Morakot; Illien-Junger, Svenja; Roughley, Peter J.; Hecht, Andrew C.; Iatridis, James C.

    2015-01-01

    Objective Intervertebral disc (IVD) degeneration is an important contributor to the development of back pain, and a key factor relating pain and degeneration are the presence of pro-inflammatory cytokines and IVD motion. There is surprisingly limited understanding of how mechanics and inflammation interact in the IVD. This study investigated interactions between mechanical loading and pro-inflammatory cytokines in a large animal organ culture model to address fundamental questions regarding (i.) how inflammatory mediators arise within the IVD, (ii.) how long inflammatory mediators persist, and (iii.) how inflammatory mediators influence IVD biomechanics. Methods Bovine caudal IVDs were cultured for 6 or 20-days under static & dynamic loading with or without exogenous TNFα in the culture medium, simulating a consequence of inflammation of the surrounding spinal tissues. TNFα transport within the IVD was assessed via immunohistochemistry. Changes in IVD structural integrity (dimensions, histology & aggrecan degradation), biomechanical behavior (Creep, Recovery & Dynamic stiffness) and pro-inflammatory cytokines in the culture medium (ELISA) were assessed. Results TNFα was able to penetrate intact IVDs when subjected to dynamic loading but not static loading. Once transported within the IVD, pro-inflammatory mediators persisted for 4–8 days after TNFα removal. TNFα exposure induced changes in IVD biomechanics (reduced diurnal displacements & increased dynamic stiffness). Discussion This study demonstrated that exposure to TNFα, as might occur from injured surrounding tissues, can penetrate healthy intact IVDs, induce expression of additional pro-inflammatory cytokines and alter IVD mechanical behavior. We conclude that exposure to pro-inflammatory cytokine may be an initiating event in the progression of IVD degeneration in addition to being a consequence of disease. PMID:25734788

  10. Altered microtubule dynamics and vesicular transport in mouse and human MeCP2-deficient astrocytes

    PubMed Central

    Delépine, Chloé; Meziane, Hamid; Nectoux, Juliette; Opitz, Matthieu; Smith, Amos B.; Ballatore, Carlo; Saillour, Yoann; Bennaceur-Griscelli, Annelise; Chang, Qiang; Williams, Emily Cunningham; Dahan, Maxime; Duboin, Aurélien; Billuart, Pierre; Herault, Yann; Bienvenu, Thierry

    2016-01-01

    Rett syndrome (RTT) is a rare X-linked neurodevelopmental disorder, characterized by normal post-natal development followed by a sudden deceleration in brain growth with progressive loss of acquired motor and language skills, stereotypic hand movements and severe cognitive impairment. Mutations in the methyl-CpG-binding protein 2 (MECP2) cause more than 95% of classic cases. Recently, it has been shown that the loss of Mecp2 from glia negatively influences neurons in a non-cell-autonomous fashion, and that in Mecp2-null mice, re-expression of Mecp2 preferentially in astrocytes significantly improved locomotion and anxiety levels, restored respiratory abnormalities to a normal pattern and greatly prolonged lifespan compared with globally null mice. We now report that microtubule (MT)-dependent vesicle transport is altered in Mecp2-deficient astrocytes from newborn Mecp2-deficient mice compared with control wild-type littermates. Similar observation has been made in human MECP2 p.Arg294* iPSC-derived astrocytes. Importantly, administration of Epothilone D, a brain-penetrant MT-stabilizing natural product, was found to restore MT dynamics in Mecp2-deficient astrocytes and in MECP2 p.Arg294* iPSC-derived astrocytes in vitro. Finally, we report that relatively low weekly doses of Epothilone D also partially reversed the impaired exploratory behavior in Mecp2308/y male mice. These findings represent a first step toward the validation of an innovative treatment for RTT. PMID:26604147

  11. Altered dopamine transporter function and phosphorylation following chronic cocaine self-administration and extinction in rats.

    PubMed

    Ramamoorthy, Sammanda; Samuvel, Devadoss J; Balasubramaniam, Annamalai; See, Ronald E; Jayanthi, Lankupalle D

    2010-01-15

    Cocaine binds with the dopamine transporter (DAT), an effect that has been extensively implicated in its reinforcing effects. However, persisting adaptations in DAT regulation after cocaine self-administration have not been extensively investigated. Here, we determined the changes in molecular mechanisms of DAT regulation in the caudate-putamen (CPu) and nucleus accumbens (NAcc) of rats with a history of cocaine self-administration, followed by 3weeks of withdrawal under extinction conditions (i.e., no cocaine available). DA uptake was significantly higher in the CPu of cocaine-experienced animals as compared to saline-yoked controls. DAT V(max) was elevated in the CPu without changes in apparent affinity for DA. In spite of elevated CPu DAT activity, total and surface DAT density and DAT-PP2Ac (protein phosphatase 2A catalytic subunit) interaction remained unaltered, although p-Ser- DAT phosphorylation was elevated. In contrast to the CPu, there were no differences between cocaine and saline rats in the levels of DA uptake, DAT V(max) and K(m) values, total and surface DAT, p-Ser-DAT phosphorylation, or DAT-PP2Ac interactions in the NAcc. These results show that chronic cocaine self-administration leads to lasting, regionally specific alterations in striatal DA uptake and DAT-Ser phosphorylation. Such changes may be related to habitual patterns of cocaine-seeking observed during relapse. Copyright 2009 Elsevier Inc. All rights reserved.

  12. Second Cancers After Colorectal Cancer

    MedlinePlus

    ... After Colorectal Cancer Colorectal Cancer After Treatment Second Cancers After Colorectal Cancer Colorectal cancer survivors can be affected by a ... many of these cancers. Follow-up after colorectal cancer treatment After completing treatment for colorectal cancer, you ...

  13. Auxin Transport and Ribosome Biogenesis Mutant/Reporter Lines to Study Plant Cell Growth and Proliferation under Altered Gravity

    NASA Astrophysics Data System (ADS)

    Valbuena, Miguel A.; Manzano, Ana I.; van Loon, Jack JWA.; Saez-Vasquez, Julio; Carnero-Diaz, Eugenie; Herranz, Raul; Medina, F. J.

    2013-02-01

    We tested different Arabidopsis thaliana strains to check their availability for space use in the International Space Station (ISS). We used mutants and reporter gene strains affecting factors of cell proliferation and cell growth, to check variations induced by an altered gravity vector. Seedlings were grown either in a Random Positioning Machine (RPM), under simulated microgravity (μg), or in a Large Diameter Centrifuge (LDC), under hypergravity (2g). A combination of the two devices (μgRPM+LDC) was also used. Under all gravity alterations, seedling roots were longer than in control 1g conditions, while the levels of the nucleolar protein nucleolin were depleted. Alterations in the pattern of expression of PIN2, an auxin transporter, and of cyclin B1, a cell cycle regulator, were shown. All these alterations are compatible with previous space data, so the use of these strains will be useful in the next experiments in ISS, under real microgravity.

  14. Infectious Prion Protein Alters Manganese Transport and Neurotoxicity in a Cell Culture Model of Prion Disease

    PubMed Central

    Martin, Dustin P.; Anantharam, Vellareddy; Jin, Huajun; Witte, Travis; Houk, Robert; Kanthasamy, Arthi; Kanthasamy, Anumantha G.

    2011-01-01

    Protein misfolding and aggregation are considered key features of many neurodegenerative diseases, but biochemical mechanisms underlying protein misfolding and the propagation of protein aggregates are not well understood. Prion disease is a classical neurodegenerative disorder resulting from the misfolding of endogenously expressed normal cellular prion protein (PrPC). Although the exact function of PrPC has not been fully elucidated, studies have suggested that it can function as a metal binding protein. Interestingly, increased brain manganese (Mn) levels have been reported in various prion diseases indicating divalent metals also may play a role in the disease process. Recently, we reported that PrPC protects against Mn-induced cytotoxicity in a neural cell culture model. To further understand the role of Mn in prion diseases, we examined Mn neurotoxicity in an infectious cell culture model of prion disease. Our results show CAD5 scrapie-infected cells were more resistant to Mn neurotoxicity as compared to uninfected cells (EC50 = 428.8 μM for CAD5 infected cells vs. 211.6 μM for uninfected cells). Additionally, treatment with 300 μM Mn in persistently infected CAD5 cells showed a reduction in mitochondrial impairment, caspase-3 activation, and DNA fragmentation when compared to uninfected cells. Scrapie-infected cells also showed significantly reduced Mn uptake as measured by inductively coupled plasma-mass spectrometry (ICP-MS), and altered expression of metal transporting proteins DMT1 and transferrin. Together, our data indicate that conversion of PrP to the pathogenic isoform enhances its ability to regulate Mn homeostasis, and suggest that understanding the interaction of metals with disease-specific proteins may provide further insight to protein aggregation in neurodegenerative diseases. PMID:21871919

  15. Phosphorylation at serine 52 and 635 does not alter the transport properties of glucosinolate transporter AtGTR1

    PubMed Central

    Jørgensen, Morten Egevang; Olsen, Carl Erik; Halkier, Barbara Ann; Nour-Eldin, Hussam Hassan

    2016-01-01

    Little is known about how plants regulate transporters of defense compounds. In A. thaliana, glucosinolates are transported between tissues by NPF2.10 (AtGTR1) and NPF2.11 (AtGTR2). Mining of the PhosPhat4.0 database showed two cytosol exposed phosphorylation sites for AtGTR1 and one membrane-buried phosphorylation site for AtGTR2. In this study, we investigate whether mutation of the two potential regulatory sites of AtGTR1 affected transport of glucosinolates in Xenopus oocytes. Characterization of AtGTR1 phosphorylation mutants showed that phosphorylation of AtGTR1 - at the two reported phosphorylation sites - is not directly involved in regulating AtGTR1 transport activity. We hypothesize a role for AtGTR1-phosphorylation in regulating protein-protein interactions. PMID:26340317

  16. Phosphorylation at serine 52 and 635 does not alter the transport properties of glucosinolate transporter AtGTR1.

    PubMed

    Jørgensen, Morten Egevang; Olsen, Carl Erik; Halkier, Barbara Ann; Nour-Eldin, Hussam Hassan

    2016-01-01

    Little is known about how plants regulate transporters of defense compounds. In A. thaliana, glucosinolates are transported between tissues by NPF2.10 (AtGTR1) and NPF2.11 (AtGTR2). Mining of the PhosPhat4.0 database showed two cytosol exposed phosphorylation sites for AtGTR1 and one membrane-buried phosphorylation site for AtGTR2. In this study, we investigate whether mutation of the two potential regulatory sites of AtGTR1 affected transport of glucosinolates in Xenopus oocytes. Characterization of AtGTR1 phosphorylation mutants showed that phosphorylation of AtGTR1 - at the two reported phosphorylation sites - is not directly involved in regulating AtGTR1 transport activity. We hypothesize a role for AtGTR1-phosphorylation in regulating protein-protein interactions.

  17. Altered glycaemia differentially modulates efflux transporter expression and activity in hCMEC/D3 cell line.

    PubMed

    Sajja, Ravi K; Cucullo, Luca

    2015-06-26

    The unique phenotype of blood-brain barrier (BBB) endothelium is partly maintained by abundant expression of ATP-binding cassette superfamily of efflux transporters that strictly restrict the CNS access to toxic substances including xenobiotics in circulation. Previously, we have shown that diabetes-related altered glycemic conditions differentially affect and compromise BBB integrity. However, the impact of diabetes on BBB efflux transporters is less understood. In this study, we examined the effects of single or repeated episodes of hypo-and hyperglycemia on major BBB efflux transporters expression/function in human cerebromicrovascular endothelial cell line (hCMEC/D3). Cells were exposed to normal (5.5 mM), hypo (2.2 mM) or hyper (25 or 35 mM)-glycemic media containing D-glucose for 12h (acute) or two 3h episodes/day of hypo- or hyperglycemia with an intercalated 2h normalglycemic exposure for 3 days ("glycemic variability", see Methods). Acute hypoglycemic exposure (12h) up-regulated BBB endothelial mRNA and protein expression of P-glycoprotein, BCRP and other multidrug resistance associated proteins (MRP1 and 4) paralleled by an increase in transporter-specific efflux activity (∼ 2-fold vs. control). Although, 12h hyperglycemia did not affect the efflux transporter expression (except for MRP4), a significant increase in BCRP activity was observed. By contrast, DNA microarray data revealed that repeated hyperglycemic episodes (but not hypoglycemia) significantly up-regulate P-glycoprotein expression and activity. Thus, this study suggests a differential impact of altered glycemic conditions on major BBB drug efflux transporters expression/function, sensitive to the length of exposure (acute vs. repeated), with an implication for altered CNS drug disposition in diabetic population.

  18. Prenatal transportation alters the metabolic response of Brahman bull calves exposed to a lipopolysaccharide (LPS) challenge

    USDA-ARS?s Scientific Manuscript database

    This study was designed to determine if prenatal transportation influences the metabolic response to a postnatal lipopolysaccharide (LPS) challenge. Pregnant Brahman cows (n=96) matched by age and parity were separated into transported (TRANS; n=48; transported for 2 hours on gestational day 60, 80,...

  19. Real time measurements of sediment transport and bed morphology during channel altering flow and sediment transport events

    NASA Astrophysics Data System (ADS)

    Curran, Joanna Crowe; Waters, Kevin A.; Cannatelli, Kristen M.

    2015-09-01

    Real-time measurements of bed changes over a reach are a missing piece needed to link bed morphology with sediment transport processes during unsteady flows when the bed adjusts quickly to changing transport rates or visual observation of the bed is precluded by fine sediment in the water column. A new technique is presented that provides continuous measurement of sediment movement over the length of a flume. A bedload monitoring system (BLMS) was developed that makes use of pressure pillows under a false flume bottom to measure sediment and water weights over discrete flume channel sections throughout a flow event. This paper details the construction of the BLMS and provides examples of its use in a laboratory setting to reconstruct bed slopes during unsteady flows and to create a real-time record of sediment transport rates across the flume channel bed during a sediment transporting flow. Data gathered from the BLMS compared well against techniques commonly in use in flume studies. When the BLMS was analyzed in conjunction with bed surface DEMs and differenced DEMs, a complete transport and bed adjustment picture was constructed. The difference DEMs provided information on the spatial extent of bed morphology changes. The BLMS supplied the data record necessary to reconstruct sediment transport records through the downstream channel, including locations and time periods of temporary sediment storage and supply. The BLMS makes it possible to construct a continuous record of the spatial distribution of sediment movement through the flume, including areas of temporary aggradation and degradation. Exciting implications of future research that incorporates a BLMS include a more informed management of river systems as a result of improved temporal predictions of sediment movement and the associated changes in channel slope and bed morphology.

  20. COLORECTAL CANCER

    PubMed Central

    Kuipers, Ernst J.; Grady, William M.; Lieberman, David; Seufferlein, Thomas; Sung, Joseph J.; Boelens, Petra G.; van de Velde, Cornelis J. H.; Watanabe, Toshiaki

    2016-01-01

    Colorectal cancer had a low incidence several decades ago. However, it has become a predominant cancer and now accounts for approximately 10% of cancer-related mortality in western countries. The ‘rise’ of colorectal cancer in developed countries can be attributed to the increasingly ageing population, unfavourable modern dietary habits and an increase in risk factors such as smoking, low physical exercise and obesity. New treatments for primary and metastatic colorectal cancer have emerged, providing additional options for patients; these treatments include laparoscopic surgery for primary disease, more-aggressive resection of metastatic disease (such as liver and pulmonary metastases), radiotherapy for rectal cancer and neoadjuvant and palliative chemotherapies. However, these new treatment options have had limited impact on cure rates and long-term survival. For these reasons, and the recognition that colorectal cancer is long preceded by a polypoid precursor, screening programmes have gained momentum. This Primer provides an overview of the current state of art knowledge on the epidemiology and mechanisms of colorectal cancer, as well as on diagnosis and treatment. PMID:27189416

  1. 49 CFR 37.43 - Alteration of transportation facilities by public entities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... that, to the maximum extent feasible, the path of travel to the altered area and the bathrooms.... Provided, that alterations to the path of travel, drinking fountains, telephones and bathrooms are not... areas (except those involving non-occupiable spaces accessed only by ladders, catwalks, crawl...

  2. Three dimensional model evaluation of physical alterations of the Caloosahatchee River and Estuary: Impact on salt transport

    NASA Astrophysics Data System (ADS)

    Sun, Detong; Wan, Yongshan; Qiu, Chelsea

    2016-05-01

    Numerical hydrodynamic modeling provides quantitative understanding of how physical alterations of an estuary may alter the waterbody hydrodynamics and the rate of mixing with the ocean. In this study, a three dimensional hydrodynamic model (CH3D) was used to compare simulated salinities between the existing condition and five historical cases representing varying physical alterations of the Caloosahatchee Estuary involving (1) removal of the headwater structure (S-79); (2) removal of the downstream causeway to Sanibel Island; (3) backfilling an oyster bar near the estuary month; (4) refilling the navigation channel; and (5) the pre-development bathymetric condition. The results suggested that some alterations including the Sanibel Causeway, backfilling the oyster bar and the S-79 structure may have some local effects but did not change estuarine salinity structure significantly. Refilling the navigation channel had a more profound effect, resulting in a dry season salinity reduction of about 5 when compared with the existing condition. The reduced salt transport was more pronounced with the pre-development bathymetry because the estuary as a whole was much shallower than today. The significant system-wide increase in salt transport caused by the historic dredging of the navigation channel in the Caloosahatchee Estuary has significant implications in the development of attainable environmental flow targets for protecting the estuarine ecosystem.

  3. Exposure to altered gravity conditions results in hypoxia-related enhancement of the presynaptic transporter-mediated release of glutamate.

    NASA Astrophysics Data System (ADS)

    Borisova, Tatiana

    High-affinity Na+-dependent glutamate transporters locate in the plasma membrane and maintain the low concentration of glutamate in synaptic cleft by the uptake of glutamate into neurons. Under hypoxic conditions glutamate transporters contribute to the glutamate release due to functioning in reverse mode. The release of glutamate via reverse-operated Na+-dependent glutamate transporters was investigated in brain synaptosomes under conditions of centrifugeinduced hypergravity. Flow cytometric analisis revealed similarity in the size and cytoplasmic granularity of control and hypergravity synaptosomes. Protonophore FCCP dissipates the proton gradient across synaptic vesicle thus synaptic vesicles are not able to keep glutamate inside. 1 microM FCCP induced the release of 4. 8 ±1. 0 % and 8. 0 ±1. 0 % of total accumulated synaptosomal label in control and G-loaded animals, respectively. Ca 2+-independent high- KCl stimulated L-[14C]glutamate release from synaptosomes preliminary treated with FCCP increased considerably from 27. 0 ± 2. 2 % to 35. 0 ± 2. 3 % after centrifuge-induced hypergravity. No-transportable inhibitor of glutamate transporter DL-threo-beta-benzyloxyaspartate was found to inhibit high-KCl and FCCP-stimulated release of L-[14C]glutamate, thus the release was concluded to occur due to reversal of glutamate transporters. We have also found the inhibition of the activity of Na \\ K ATPase in the plasma membrane of synaptosomes after hypergravity that might also contribute to the enhancement of the transporter-mediated release of glutamate. These hypergravity-induced alterations in the transporter-mediated release of glutamate were suggested to correlate with the hypoxic injury of neurons. The changes we have revealed for the transporter-mediated release of glutamate may lead to mental disorders, upcoming seizures and neurotoxicity under hypergravity conditions.

  4. Overexpression of Laccaria bicolor aquaporin JQ585595 alters root water transport properties in ectomycorrhizal white spruce (Picea glauca) seedlings.

    PubMed

    Xu, Hao; Kemppainen, Minna; El Kayal, Walid; Lee, Seong Hee; Pardo, Alejandro G; Cooke, Janice E K; Zwiazek, Janusz J

    2015-01-01

    The contribution of hyphae to water transport in ectomycorrhizal (ECM) white spruce (Picea glauca) seedlings was examined by altering expression of a major water-transporting aquaporin in Laccaria bicolor. Picea glauca was inoculated with wild-type (WT), mock transgenic or L. bicolor aquaporin JQ585595-overexpressing (OE) strains and exposed to root temperatures ranging from 5 to 20°C to examine the root water transport properties, physiological responses and plasma membrane intrinsic protein (PIP) expression in colonized plants. Mycorrhization increased shoot water potential, transpiration, net photosynthetic rates, root hydraulic conductivity and root cortical cell hydraulic conductivity in seedlings. At 20°C, OE plants had higher root hydraulic conductivity compared with WT plants and the increases were accompanied by higher expression of P. glauca PIP GQ03401_M18.1 in roots. In contrast to WT L. bicolor, the effects of OE fungi on root and root cortical cell hydraulic conductivities were abolished at 10 and 5°C in the absence of major changes in the examined transcript levels of P. glauca root PIPs. The results provide evidence for the importance of fungal aquaporins in root water transport of mycorrhizal plants. They also demonstrate links between hyphal water transport, root aquaporin expression and root water transport in ECM plants.

  5. Chemical transport in geothermal systems in Iceland: Evidence from hydrothermal alteration

    NASA Astrophysics Data System (ADS)

    Franzson, Hjalti; Zierenberg, Robert; Schiffman, Peter

    2008-06-01

    This study focuses on the chemical changes in basaltic rocks in fossil low- and high-temperature hydrothermal systems in Iceland. The method used takes into account the amount of dilution caused by vesicle and vein fillings in the rocks. The amount of dilution allows a calculation of the primary concentration of the immobile element Zr, and by multiplying the composition of the altered rock by the ratio of Zr (protolith)/Zr (altered rock) one can compute the mass addition caused by the dilution of the void fillings, and also make a direct comparison with the likely protoliths from the same areas. The samples were divided into three groups; two from Tertiary fossil high-temperature systems (Hafnarfjall, Geitafell), and the third group from a low temperature, zeolite-altered plateau basalt succession. The results show that hydrothermally altered rocks are enriched in Si, Al, Fe, Mg and Mn, and that Na, K and Ca are mobile but show either depletion or enrichment. The elements that are immobile include Zr, Y, Nb and probably Ti. The two high-temperature systems show quite similar chemical alteration trends, an observation which may apply to Icelandic fresh water high-temperature systems in general. The geochemical data show that the major changes in the altered rocks from Icelandic geothermal systems may be attributed to addition of elements during deposition of pore-filling alteration minerals. A comparison with seawater-dominated basalt-hosted hydrothermal systems shows much greater mass flux within the seawater systems, even though both systems have similar alteration assemblages. The secondary mineral assemblages seem to be controlled predominantly by the thermal stability of the alteration phases and secondarily by the composition of the hydrothermal fluids.

  6. Diabetes and exposure to peritoneal dialysis solutions alter tight junction proteins and glucose transporters of rat peritoneal mesothelial cells.

    PubMed

    Debray-García, Yazmin; Sánchez, Elsa I; Rodríguez-Muñoz, Rafael; Venegas, Miguel A; Velazquez, Josue; Reyes, José L

    2016-09-15

    To evaluate alterations in tight junction (TJ) proteins and glucose transporters in rat peritoneal mesothelial cells (RPMC) from diabetic rats and after treatment with peritoneal dialysis solutions (PDS) in vitro. Diabetes was induced in female Wistar rats by streptozotocin (STZ)-injection. Twenty-one days after STZ-injection, peritoneal thickness and mesothelial cell morphology were studied by light microscopy and microvilli length and density by atomic force microscopy. RPMC were obtained from healthy and diabetic rats. Mesothelial phenotype, evaluated by cytokeratin and pan-cadherin, epithelial to mesenchymal transition (EMT), evaluated by alpha-smooth muscle action (α-SMA) and vimentin, TJ proteins, claudins-1 and -2, and occludin, and glucose transporters, sodium and glucose co-transporters (SGLT) -1 and -2 and facilitative glucose transporters (GLUT) -1 and -2 were analyzed. Also, transepithelial electrical resistance (TER) was measured. Oxidative stress was estimated by measuring reactive oxygen species production, and protein carbonylation, receptor for advanced glycation end products (RAGE), nuclear factor erythroid related factor-2 (Nrf-2), and expression of antioxidant enzymes. Peritoneal damage was present 21days after STZ-injection. Diabetes induced changes in TJ and glucose transporters in RPMC together with decreased TER. RPMC from diabetic rats showed oxidative stress, which was enhanced by exposure to PDS. In addition, RPMC from diabetic rats showed early EMT. To our knowledge, this is the first study that shows changes in TJ proteins and glucose transporters of RPMC from diabetic rats. All these alterations might explain the increased peritoneal permeability observed in diabetic patients undergoing peritoneal dialysis. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 49 CFR 37.43 - Alteration of transportation facilities by public entities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... affects or could affect the usability of the facility or part of the facility, the entity shall make the... public entity undertakes an alteration that affects or could affect the usability of or access to an area...

  8. 49 CFR 37.43 - Alteration of transportation facilities by public entities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... affects or could affect the usability of the facility or part of the facility, the entity shall make the... public entity undertakes an alteration that affects or could affect the usability of or access to an...

  9. 49 CFR 37.43 - Alteration of transportation facilities by public entities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... affects or could affect the usability of the facility or part of the facility, the entity shall make the... public entity undertakes an alteration that affects or could affect the usability of or access to an...

  10. Alterations in rotation thromboelastometry (ROTEM®) parameters: point-of-care testing vs analysis after pneumatic tube system transport.

    PubMed

    Martin, J; Schuster, T; Moessmer, G; Kochs, E F; Wagner, K J

    2012-10-01

    Thromboelastometry as point-of-care (POC) testing enables the analysis of the clotting process at the bedside, providing rapid results to guide haemostatic therapy. However, POC testing utilizes medical staff who are managing critically ill patients, as non-laboratory personnel may not be sufficiently trained to run the devices. To resolve these problems, thromboelastometry can be performed in the central laboratory and rapid transport of samples can be accomplished via a pneumatic tube system (PTS). This study compares thromboelastometry parameters of blood samples analysed immediately with those analysed after PTS transport. In patients with normal haemostasis, two arterial blood samples were collected from each patient (n=92) in citrated plastic tubes to investigate the assays INTEM (n=35), EXTEM (n=27), and FIBTEM (n=30). One blood sample was analysed immediately, the other sample after PTS transport. Thromboelastometry was performed using a single ROTEM(®) device. The mean clot firmness values were significantly lower for PTS samples in both the INTEM (-0.7 mm cf. -1.1 mm) and EXTEM (-1.4 cf. -1.7 mm) assays. INTEM coagulation time (CT) was significantly lower in PTS samples with a mean difference of -13 s. EXTEM CT was significantly higher in PTS samples with a mean difference of +3.9 s. Thromboelastometry parameters of blood samples analysed after PTS transport are significantly altered compared with those analysed immediately. However, in patients with normal haemostasis, the alterations were small and without clinical consequence, implying that analysis after PTS transport is an acceptable alternative to prompt analysis at the bedside. Further studies should focus on patients with impaired haemostasis.

  11. SNPs altering ammonium transport activity of human Rhesus factors characterized by a yeast-based functional assay.

    PubMed

    Deschuyteneer, Aude; Boeckstaens, Mélanie; De Mees, Christelle; Van Vooren, Pascale; Wintjens, René; Marini, Anna Maria

    2013-01-01

    Proteins of the conserved Mep-Amt-Rh family, including mammalian Rhesus factors, mediate transmembrane ammonium transport. Ammonium is an important nitrogen source for the biosynthesis of amino acids but is also a metabolic waste product. Its disposal in urine plays a critical role in the regulation of the acid/base homeostasis, especially with an acid diet, a trait of Western countries. Ammonium accumulation above a certain concentration is however pathologic, the cytotoxicity causing fatal cerebral paralysis in acute cases. Alteration in ammonium transport via human Rh proteins could have clinical outcomes. We used a yeast-based expression assay to characterize human Rh variants resulting from non synonymous single nucleotide polymorphisms (nsSNPs) with known or unknown clinical phenotypes and assessed their ammonium transport efficiency, protein level, localization and potential trans-dominant impact. The HsRhAG variants (I61R, F65S) associated to overhydrated hereditary stomatocytosis (OHSt), a disease affecting erythrocytes, proved affected in intrinsic bidirectional ammonium transport. Moreover, this study reveals that the R202C variant of HsRhCG, the orthologue of mouse MmRhcg required for optimal urinary ammonium excretion and blood pH control, shows an impaired inherent ammonium transport activity. Urinary ammonium excretion was RHcg gene-dose dependent in mouse, highlighting MmRhcg as a limiting factor. HsRhCG(R202C) may confer susceptibility to disorders leading to metabolic acidosis for instance. Finally, the analogous R211C mutation in the yeast ScMep2 homologue also impaired intrinsic activity consistent with a conserved functional role of the preserved arginine residue. The yeast expression assay used here constitutes an inexpensive, fast and easy tool to screen nsSNPs reported by high throughput sequencing or individual cases for functional alterations in Rh factors revealing potential causal variants.

  12. SNPs Altering Ammonium Transport Activity of Human Rhesus Factors Characterized by a Yeast-Based Functional Assay

    PubMed Central

    Deschuyteneer, Aude; Boeckstaens, Mélanie; De Mees, Christelle; Van Vooren, Pascale; Wintjens, René; Marini, Anna Maria

    2013-01-01

    Proteins of the conserved Mep-Amt-Rh family, including mammalian Rhesus factors, mediate transmembrane ammonium transport. Ammonium is an important nitrogen source for the biosynthesis of amino acids but is also a metabolic waste product. Its disposal in urine plays a critical role in the regulation of the acid/base homeostasis, especially with an acid diet, a trait of Western countries. Ammonium accumulation above a certain concentration is however pathologic, the cytotoxicity causing fatal cerebral paralysis in acute cases. Alteration in ammonium transport via human Rh proteins could have clinical outcomes. We used a yeast-based expression assay to characterize human Rh variants resulting from non synonymous single nucleotide polymorphisms (nsSNPs) with known or unknown clinical phenotypes and assessed their ammonium transport efficiency, protein level, localization and potential trans-dominant impact. The HsRhAG variants (I61R, F65S) associated to overhydrated hereditary stomatocytosis (OHSt), a disease affecting erythrocytes, proved affected in intrinsic bidirectional ammonium transport. Moreover, this study reveals that the R202C variant of HsRhCG, the orthologue of mouse MmRhcg required for optimal urinary ammonium excretion and blood pH control, shows an impaired inherent ammonium transport activity. Urinary ammonium excretion was RHcg gene-dose dependent in mouse, highlighting MmRhcg as a limiting factor. HsRhCGR202C may confer susceptibility to disorders leading to metabolic acidosis for instance. Finally, the analogous R211C mutation in the yeast ScMep2 homologue also impaired intrinsic activity consistent with a conserved functional role of the preserved arginine residue. The yeast expression assay used here constitutes an inexpensive, fast and easy tool to screen nsSNPs reported by high throughput sequencing or individual cases for functional alterations in Rh factors revealing potential causal variants. PMID:23967154

  13. Organophosphate Related Alterations in Myelin and Axonal Transport in the Living Mammalian Brain

    DTIC Science & Technology

    2015-10-01

    we evaluated the effects of the commonly used OP- pesticide , chlorpyrifos (CPF) on axonal transport in the brains of living rats using manganese (Mn2...Environ Health Perspect 2004;112(9):950–8. Karlsson JO, Hansson HA, Sjöstrand J. Effect of colchicine on axonal transport and morphology of retinal...Pope CN. Organophosphorus pesticides : do they all have the same mechanism of toxicity? J Toxicol Environ Health B Crit Rev 1999;2:161–81. Pope C

  14. Shoot Na+ exclusion and increased salinity tolerance engineered by cell type-specific alteration of Na+ transport in Arabidopsis.

    PubMed

    Møller, Inge S; Gilliham, Matthew; Jha, Deepa; Mayo, Gwenda M; Roy, Stuart J; Coates, Juliet C; Haseloff, Jim; Tester, Mark

    2009-07-01

    Soil salinity affects large areas of cultivated land, causing significant reductions in crop yield globally. The Na+ toxicity of many crop plants is correlated with overaccumulation of Na+ in the shoot. We have previously suggested that the engineering of Na+ exclusion from the shoot could be achieved through an alteration of plasma membrane Na+ transport processes in the root, if these alterations were cell type specific. Here, it is shown that expression of the Na+ transporter HKT1;1 in the mature root stele of Arabidopsis thaliana decreases Na+ accumulation in the shoot by 37 to 64%. The expression of HKT1;1 specifically in the mature root stele is achieved using an enhancer trap expression system for specific and strong overexpression. The effect in the shoot is caused by the increased influx, mediated by HKT1;1, of Na+ into stelar root cells, which is demonstrated in planta and leads to a reduction of root-to-shoot transfer of Na+. Plants with reduced shoot Na+ also have increased salinity tolerance. By contrast, plants constitutively expressing HKT1;1 driven by the cauliflower mosaic virus 35S promoter accumulated high shoot Na+ and grew poorly. Our results demonstrate that the modification of a specific Na+ transport process in specific cell types can reduce shoot Na+ accumulation, an important component of salinity tolerance of many higher plants.

  15. Genetical and Comparative Genomics of Brassica under Altered Ca Supply Identifies Arabidopsis Ca-Transporter Orthologs[W][OPEN

    PubMed Central

    Graham, Neil S.; Hammond, John P.; Lysenko, Artem; Mayes, Sean; Ó Lochlainn, Seosamh; Blasco, Bego; Bowen, Helen C.; Rawlings, Chris J.; Rios, Juan J.; Welham, Susan; Carion, Pierre W.C.; Dupuy, Lionel X.; King, Graham J.; White, Philip J.; Broadley, Martin R.

    2014-01-01

    Although Ca transport in plants is highly complex, the overexpression of vacuolar Ca2+ transporters in crops is a promising new technology to improve dietary Ca supplies through biofortification. Here, we sought to identify novel targets for increasing plant Ca accumulation using genetical and comparative genomics. Expression quantitative trait locus (eQTL) mapping to 1895 cis- and 8015 trans-loci were identified in shoots of an inbred mapping population of Brassica rapa (IMB211 × R500); 23 cis- and 948 trans-eQTLs responded specifically to altered Ca supply. eQTLs were screened for functional significance using a large database of shoot Ca concentration phenotypes of Arabidopsis thaliana. From 31 Arabidopsis gene identifiers tagged to robust shoot Ca concentration phenotypes, 21 mapped to 27 B. rapa eQTLs, including orthologs of the Ca2+ transporters At-CAX1 and At-ACA8. Two of three independent missense mutants of BraA.cax1a, isolated previously by targeting induced local lesions in genomes, have allele-specific shoot Ca concentration phenotypes compared with their segregating wild types. BraA.CAX1a is a promising target for altering the Ca composition of Brassica, consistent with prior knowledge from Arabidopsis. We conclude that multiple-environment eQTL analysis of complex crop genomes combined with comparative genomics is a powerful technique for novel gene identification/prioritization. PMID:25082855

  16. Alterations in Adhesion, Transport, and Membrane Characteristics in an Adhesion-Deficient Pseudomonad

    PubMed Central

    DeFlaun, M. F.; Oppenheimer, S. R.; Streger, S.; Condee, C. W.; Fletcher, M.

    1999-01-01

    A stable adhesion-deficient mutant of Burkholderia cepacia G4, a soil pseudomonad, was selected in a sand column assay. This mutant (ENV435) was compared to the wild-type strain by examining the adhesion of the organisms to silica sand and their transport through two aquifer sediments that differed in their sand, silt, and clay contents. We compared the longitudinal transport of the wild type and the adhesion mutant to the transport of a conservative chloride tracer in 25-cm-long glass columns. The transport of the wild-type strain was severely retarded compared to the transport of the conservative tracer in a variety of aquifer sediments, while the adhesion mutant and the conservative tracer traveled at similar rates. An intact sediment core study produced similar results; ENV435 was transported at a faster rate and in much greater numbers than G4. The results of hydrophobic interaction chromatography revealed that G4 was significantly more hydrophobic than ENV435, and polyacrylamide gel electrophoresis revealed significant differences in the lipopolysaccharide O-antigens of the adhesion mutant and the wild type. Differences in this cell surface polymer may explain the decreased adhesion of strain ENV435. PMID:9925613

  17. Early alterations in soleus GLUT-4, glucose transport, and glycogen in voluntary running rats

    NASA Technical Reports Server (NTRS)

    Henriksen, Erik J.; Halseth, Amy E.

    1994-01-01

    Voluntary wheel running (WR) by juvenile female rats was used as a noninterventional model of soleus muscle functional overload to study the regulation of insulin-stimulated glucose transport activity by the glucose transporter (GLUT-4 isoform) protein level and glycogen concentration. Soleus total protein content was significantly greater (+18%;P greater than 0.05) than in age-matched controls after 1 wk of WR, and this hypertrophic response continued in weeks 2-4 (+24-32%). GLUT-4 protein was 39% greater than in controls in 1-wk WR soleus, and this adaptation was accompanied by a similar increase in in vitro insulin-stimulated glucose transport activity(+29%). After 2 and 4 wk of WR, however, insulin-stimulated glucose transport activity had returned to control levels, despite a continued elevation (+25-28%) of GLUT-4 protein. At these two time points, glycogen concentration was significantly enhanced in WR soleus (+21-42%), which coincided with significant reductions in glycogen synthase activity ratios (-23 to-41%). These results indicate that, in this model of soleus muscle functional overload, the GLUT-4 protein level may initially regulate insulin-stimulated glucose transport activity in the absence of changes in other modifying factors. However,this regulation of glucose transport activity by GLUT-4 protein may be subsequently overridden by elevated glycogen concentration.

  18. Early alterations in soleus GLUT-4, glucose transport, and glycogen in voluntary running rats

    NASA Technical Reports Server (NTRS)

    Henriksen, Erik J.; Halseth, Amy E.

    1994-01-01

    Voluntary wheel running (WR) by juvenile female rats was used as a noninterventional model of soleus muscle functional overload to study the regulation of insulin-stimulated glucose transport activity by the glucose transporter (GLUT-4 isoform) protein level and glycogen concentration. Soleus total protein content was significantly greater (+18%;P greater than 0.05) than in age-matched controls after 1 wk of WR, and this hypertrophic response continued in weeks 2-4 (+24-32%). GLUT-4 protein was 39% greater than in controls in 1-wk WR soleus, and this adaptation was accompanied by a similar increase in in vitro insulin-stimulated glucose transport activity(+29%). After 2 and 4 wk of WR, however, insulin-stimulated glucose transport activity had returned to control levels, despite a continued elevation (+25-28%) of GLUT-4 protein. At these two time points, glycogen concentration was significantly enhanced in WR soleus (+21-42%), which coincided with significant reductions in glycogen synthase activity ratios (-23 to-41%). These results indicate that, in this model of soleus muscle functional overload, the GLUT-4 protein level may initially regulate insulin-stimulated glucose transport activity in the absence of changes in other modifying factors. However,this regulation of glucose transport activity by GLUT-4 protein may be subsequently overridden by elevated glycogen concentration.

  19. Presynaptic transporter-mediated release of glutamate evoked by the protonophore FCCP increases under altered gravity conditions

    NASA Astrophysics Data System (ADS)

    Borisova, T. A.; Krisanova, N. V.

    2008-12-01

    High-affinity Na +-dependent glutamate transporters of the plasma membrane mediate the glutamate uptake into neurons, and thus maintain low levels of extracellular glutamate in the synaptic cleft. The study focused on the release of glutamate by reversal of Na +-dependent glutamate transporters from rat brain nerve terminals (synaptosomes) under conditions of centrifuge-induced hypergravity. Flow cytometric analysis revealed similarity in the size and cytoplasmic granularity between synaptosomal preparations obtained from control and G-loaded animals (10 G, 1 h). The release of cytosolic L-[ 14C]glutamate from synaptosomes was evaluated using the protonophore FCCP, which dissipated synaptic vesicle proton gradient, thus synaptic vesicles were not able to keep glutamate inside and the latter enriched cytosol. FCCP per se induced the greater release of L-[ 14C]glutamate in hypergravity as compared to control (4.8 ± 1.0% and 8.0 ± 1.0% of total label). Exocytotic release of L-[ 14C]glutamate evoked by depolarization was reduced down to zero after FCCP application under both conditions studied. Depolarization stimulated release of cytosolic L-[ 14C]glutamate from synaptosomes preliminary treated with FCCP was considerably increased from 27.0 ± 2.2% of total label in control to 35.0 ± 2.3% in hypergravity. Non-transportable inhibitor of glutamate transporter DL-threo-β-benzyloxyaspartate was found to significantly inhibit high-KCl and FCCP-stimulated release of L-[ 14C]glutamate, confirming the release by reversal of glutamate transporters. The enhancement of transporter-mediated release of glutamate in hypergravity was found to result at least partially from the inhibition of the activity of Na/K-ATPase in the plasma membrane of synaptosomes. We suggested that hypergravity-induced alteration in transporter-mediated release of glutamate indicated hypoxic injury of neurons.

  20. Dopamine transporter (DAT) genetic hypofunction in mice produces alterations consistent with ADHD but not schizophrenia or bipolar disorder.

    PubMed

    Mereu, M; Contarini, G; Buonaguro, E F; Latte, G; Managò, F; Iasevoli, F; de Bartolomeis, A; Papaleo, F

    2017-07-15

    ADHD, schizophrenia and bipolar disorder are psychiatric diseases with a strong genetic component which share dopaminergic alterations. Dopamine transporter (DAT) genetics might be potentially implicated in all these disorders. However, in contrast to DAT absence, the effects of DAT hypofunction especially in developmental trajectories have been scarcely addressed. Thus, we comprehensively studied DAT hypofunctional mice (DAT+/-) from adolescence to adulthood to disentangle DAT-dependent alterations in the development of psychiatric-relevant phenotypes. From pre-adolescence onward, DAT+/- displayed a hyperactive phenotype, while responses to external stimuli and sensorimotor gating abilities were unaltered. General cognitive impairments in adolescent DAT+/- were partially ameliorated during adulthood in males but not in females. Despite this, attentional and impulsivity deficits were evident in DAT+/- adult males. At the molecular level, DAT+/- mice showed a reduced expression of Homer1a in the prefrontal cortex, while other brain regions as well as Arc and Homer1b expression were mostly unaffected. Amphetamine treatments reverted DAT+/- hyperactivity and rescued cognitive deficits. Moreover, amphetamine shifted DAT-dependent Homer1a altered expression from prefrontal cortex to striatal regions. These behavioral and molecular phenotypes indicate that a genetic-driven DAT hypofunction alters neurodevelopmental trajectories consistent with ADHD, but not with schizophrenia and bipolar disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. HUMMR, a hypoxia- and HIF-1α–inducible protein, alters mitochondrial distribution and transport

    PubMed Central

    Li, Yan; Lim, Seung; Hoffman, David; Aspenstrom, Pontus; Federoff, Howard J.

    2009-01-01

    Mitochondrial transport is critical for maintenance of normal neuronal function. Here, we identify a novel mitochondria protein, hypoxia up-regulated mitochondrial movement regulator (HUMMR), which is expressed in neurons and is markedly induced by hypoxia-inducible factor 1 α (HIF-1α). Interestingly, HUMMR interacts with Miro-1 and Miro-2, mitochondrial proteins that are critical for mediating mitochondrial transport. Interestingly, knockdown of HUMMR or HIF-1 function in neurons exposed to hypoxia markedly reduces mitochondrial content in axons. Because mitochondrial transport and distribution are inextricably linked, the impact of reduced HUMMR function on the direction of mitochondrial transport was also explored. Loss of HUMMR function in hypoxia diminished the percentage of motile mitochondria moving in the anterograde direction and enhanced the percentage moving in the retrograde direction. Thus, HUMMR, a novel mitochondrial protein induced by HIF-1 and hypoxia, biases mitochondria transport in the anterograde direction. These findings have broad implications for maintenance of neuronal viability and function during physiological and pathological states. PMID:19528298

  2. 49 CFR 37.43 - Alteration of transportation facilities by public entities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... requirements of this paragraph also apply to the alteration of existing intercity or commuter rail stations by..., as applicable) after January 25, 1992, or, in the case of intercity and commuter rail stations, after... areas, passenger waiting areas, train or bus platforms, baggage checking and return areas and...

  3. Chromosome 19q13 disruption alters expressions of CYP2A7, MIA and MIA-RAB4B lncRNA and contributes to FAP-like phenotype in APC mutation-negative familial colorectal cancer patients

    PubMed Central

    Thean, Lai Fun; Wong, Yu Hui; Lo, Michelle; Loi, Carol; Chew, Min Hoe; Tang, Choong Leong; Cheah, Peh Yean

    2017-01-01

    Familial adenomatous polyposis (FAP) is an autosomal-dominantly inherited form of colorectal cancer (CRC) caused by mutation in the adenomatous polyposis coli (APC) gene. Our ability to exhaustively screen for APC mutations identify microsatellite-stable and APC-mutation negative familial CRC patients, enabling us to search for novel genes. We performed genome-wide scan on two affected siblings of one family and 88 ethnicity- and gender-matched healthy controls to identify deletions shared by the siblings. Combined loss of heterozygosity, copy number and allelic-specific copy number analysis uncovered 5 shared deletions. Long-range polymerase chain reaction (PCR) confirmed chromosome 19q13 deletion, which was subsequently found in one other family. The 32 kb deleted region harbors the CYP2A7 gene and was enriched with enhancer, repressor and insulator sites. The wildtype allele was lost in the polyps of the proband. Further, real-time RT-PCR assays showed that expressions of MIA and MIA-RAB4B located 35 kb upstream of the deletion, were up-regulated in the polyps compared to the matched mucosa of the proband. MIA-RAB4B, the read-through long non-coding RNA (lncRNA), RAB4B, PIM2 and TAOK1 share common binding site of a microRNA, miR-24, in their 3’UTRs. PIM2 and TAOK1, two target oncogenes of miR-24, were co-ordinately up-regulated with MIA-RAB4B in the polyps, suggesting that MIA-RAB4B could function as competitive endogenous RNA to titrate miR-24 away from its other targets. The data suggest that the 19.13 deletion disrupted chromatin boundary, leading to altered expression of several genes and lncRNA, could contribute to colorectal cancer via novel genetic and epigenetic mechanisms. PMID:28306719

  4. Chromosome 19q13 disruption alters expressions of CYP2A7, MIA and MIA-RAB4B lncRNA and contributes to FAP-like phenotype in APC mutation-negative familial colorectal cancer patients.

    PubMed

    Thean, Lai Fun; Wong, Yu Hui; Lo, Michelle; Loi, Carol; Chew, Min Hoe; Tang, Choong Leong; Cheah, Peh Yean

    2017-01-01

    Familial adenomatous polyposis (FAP) is an autosomal-dominantly inherited form of colorectal cancer (CRC) caused by mutation in the adenomatous polyposis coli (APC) gene. Our ability to exhaustively screen for APC mutations identify microsatellite-stable and APC-mutation negative familial CRC patients, enabling us to search for novel genes. We performed genome-wide scan on two affected siblings of one family and 88 ethnicity- and gender-matched healthy controls to identify deletions shared by the siblings. Combined loss of heterozygosity, copy number and allelic-specific copy number analysis uncovered 5 shared deletions. Long-range polymerase chain reaction (PCR) confirmed chromosome 19q13 deletion, which was subsequently found in one other family. The 32 kb deleted region harbors the CYP2A7 gene and was enriched with enhancer, repressor and insulator sites. The wildtype allele was lost in the polyps of the proband. Further, real-time RT-PCR assays showed that expressions of MIA and MIA-RAB4B located 35 kb upstream of the deletion, were up-regulated in the polyps compared to the matched mucosa of the proband. MIA-RAB4B, the read-through long non-coding RNA (lncRNA), RAB4B, PIM2 and TAOK1 share common binding site of a microRNA, miR-24, in their 3'UTRs. PIM2 and TAOK1, two target oncogenes of miR-24, were co-ordinately up-regulated with MIA-RAB4B in the polyps, suggesting that MIA-RAB4B could function as competitive endogenous RNA to titrate miR-24 away from its other targets. The data suggest that the 19.13 deletion disrupted chromatin boundary, leading to altered expression of several genes and lncRNA, could contribute to colorectal cancer via novel genetic and epigenetic mechanisms.

  5. Genomic Convergence Analysis of Schizophrenia: mRNA Sequencing Reveals Altered Synaptic Vesicular Transport in Post-Mortem Cerebellum

    PubMed Central

    Mudge, Joann; Miller, Neil A.; Khrebtukova, Irina; Lindquist, Ingrid E.; May, Gregory D.; Huntley, Jim J.; Luo, Shujun; Zhang, Lu; van Velkinburgh, Jennifer C.; Farmer, Andrew D.; Lewis, Sharon; Beavis, William D.; Schilkey, Faye D.; Virk, Selene M.; Black, C. Forrest; Myers, M. Kathy; Mader, Lar C.; Langley, Ray J.; Utsey, John P.; Kim, Ryan W.; Roberts, Rosalinda C.; Khalsa, Sat Kirpal; Garcia, Meredith; Ambriz-Griffith, Victoria; Harlan, Richard; Czika, Wendy; Martin, Stanton; Wolfinger, Russell D.; Perrone-Bizzozero, Nora I.; Schroth, Gary P.; Kingsmore, Stephen F.

    2008-01-01

    Schizophrenia (SCZ) is a common, disabling mental illness with high heritability but complex, poorly understood genetic etiology. As the first phase of a genomic convergence analysis of SCZ, we generated 16.7 billion nucleotides of short read, shotgun sequences of cDNA from post-mortem cerebellar cortices of 14 patients and six, matched controls. A rigorous analysis pipeline was developed for analysis of digital gene expression studies. Sequences aligned to approximately 33,200 transcripts in each sample, with average coverage of 450 reads per gene. Following adjustments for confounding clinical, sample and experimental sources of variation, 215 genes differed significantly in expression between cases and controls. Golgi apparatus, vesicular transport, membrane association, Zinc binding and regulation of transcription were over-represented among differentially expressed genes. Twenty three genes with altered expression and involvement in presynaptic vesicular transport, Golgi function and GABAergic neurotransmission define a unifying molecular hypothesis for dysfunction in cerebellar cortex in SCZ. PMID:18985160

  6. Circadian clock circuitry in colorectal cancer

    PubMed Central

    Mazzoccoli, Gianluigi; Vinciguerra, Manlio; Papa, Gennaro; Piepoli, Ada

    2014-01-01

    Colorectal cancer is the most prevalent among digestive system cancers. Carcinogenesis relies on disrupted control of cellular processes, such as metabolism, proliferation, DNA damage recognition and repair, and apoptosis. Cell, tissue, organ and body physiology is characterized by periodic fluctuations driven by biological clocks operating through the clock gene machinery. Dysfunction of molecular clockworks and cellular oscillators is involved in tumorigenesis, and altered expression of clock genes has been found in cancer patients. Epidemiological studies have shown that circadian disruption, that is, alteration of bodily temporal organization, is a cancer risk factor, and an increased incidence of colorectal neoplastic disease is reported in shift workers. In this review we describe the involvement of the circadian clock circuitry in colorectal carcinogenesis and the therapeutic strategies addressing temporal deregulation in colorectal cancer. PMID:24764658

  7. Circadian clock circuitry in colorectal cancer.

    PubMed

    Mazzoccoli, Gianluigi; Vinciguerra, Manlio; Papa, Gennaro; Piepoli, Ada

    2014-04-21

    Colorectal cancer is the most prevalent among digestive system cancers. Carcinogenesis relies on disrupted control of cellular processes, such as metabolism, proliferation, DNA damage recognition and repair, and apoptosis. Cell, tissue, organ and body physiology is characterized by periodic fluctuations driven by biological clocks operating through the clock gene machinery. Dysfunction of molecular clockworks and cellular oscillators is involved in tumorigenesis, and altered expression of clock genes has been found in cancer patients. Epidemiological studies have shown that circadian disruption, that is, alteration of bodily temporal organization, is a cancer risk factor, and an increased incidence of colorectal neoplastic disease is reported in shift workers. In this review we describe the involvement of the circadian clock circuitry in colorectal carcinogenesis and the therapeutic strategies addressing temporal deregulation in colorectal cancer.

  8. Copper and ectopic expression of the Arabidopsis transport protein COPT1 alter iron homeostasis in rice (Oryza sativa L.).

    PubMed

    Andrés-Bordería, Amparo; Andrés, Fernando; Garcia-Molina, Antoni; Perea-García, Ana; Domingo, Concha; Puig, Sergi; Peñarrubia, Lola

    2017-06-19

    Copper deficiency and excess differentially affect iron homeostasis in rice and overexpression of the Arabidopsis high-affinity copper transporter COPT1 slightly increases endogenous iron concentration in rice grains. Higher plants have developed sophisticated mechanisms to efficiently acquire and use micronutrients such as copper and iron. However, the molecular mechanisms underlying the interaction between both metals remain poorly understood. In the present work, we study the effects produced on iron homeostasis by a wide range of copper concentrations in the growth media and by altered copper transport in Oryza sativa plants. Gene expression profiles in rice seedlings grown under copper excess show an altered expression of genes involved in iron homeostasis compared to standard control conditions. Thus, ferritin OsFER2 and ferredoxin OsFd1 mRNAs are down-regulated whereas the transcriptional iron regulator OsIRO2 and the nicotianamine synthase OsNAS2 mRNAs rise under copper excess. As expected, the expression of OsCOPT1, which encodes a high-affinity copper transport protein, as well as other copper-deficiency markers are down-regulated by copper. Furthermore, we show that Arabidopsis COPT1 overexpression (C1 (OE) ) in rice causes root shortening in high copper conditions and under iron deficiency. C1 (OE) rice plants modify the expression of the putative iron-sensing factors OsHRZ1 and OsHRZ2 and enhance the expression of OsIRO2 under copper excess, which suggests a role of copper transport in iron signaling. Importantly, the C1 (OE) rice plants grown on soil contain higher endogenous iron concentration than wild-type plants in both brown and white grains. Collectively, these results highlight the effects of rice copper status on iron homeostasis, which should be considered to obtain crops with optimized nutrient concentrations in edible parts.

  9. Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems

    USGS Publications Warehouse

    Worthington, Thomas A.; Brewer, Shannon K.; Farless, Nicole; Grabowski, Timothy B.; Gregory, Mark S.

    2014-01-01

    Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads) and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2–3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured) and sampling period (time period when 2.5% and 97.5% of beads were captured). Habitat complexity was assessed by calculating width:depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems.

  10. Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems.

    PubMed

    Worthington, Thomas A; Brewer, Shannon K; Farless, Nicole; Grabowski, Timothy B; Gregory, Mark S

    2014-01-01

    Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads) and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2-3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured) and sampling period (time period when 2.5% and 97.5% of beads were captured). Habitat complexity was assessed by calculating width∶depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems.

  11. Interacting Effects of Discharge and Channel Morphology on Transport of Semibuoyant Fish Eggs in Large, Altered River Systems

    PubMed Central

    Worthington, Thomas A.; Brewer, Shannon K.; Farless, Nicole; Grabowski, Timothy B.; Gregory, Mark S.

    2014-01-01

    Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads) and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2–3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured) and sampling period (time period when 2.5% and 97.5% of beads were captured). Habitat complexity was assessed by calculating width∶depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems. PMID:24802361

  12. Colorectal Cancer: Genetics is Changing Everything.

    PubMed

    Obuch, Joshua C; Ahnen, Dennis J

    2016-09-01

    Cancer is fundamentally a genetic disease caused by mutational or epigenetic alterations in DNA. There has been a remarkable expansion of the molecular understanding of colonic carcinogenesis in the last 30 years and that understanding is changing many aspects of colorectal cancer care. It is becoming increasingly clear that there are genetic subsets of colorectal cancer that have different risk factors, prognosis, and response to treatment. This article provides a general update on colorectal cancer and highlights the ways that genetics is changing clinical care. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Cellular effects of fluorodeoxyglucose: Global changes in the lipidome and alteration in intracellular transport

    PubMed Central

    Kavaliauskiene, Simona; Torgersen, Maria Lyngaas; Lingelem, Anne Berit Dyve; Klokk, Tove Irene; Lintonen, Tuulia; Simolin, Helena; Ekroos, Kim; Skotland, Tore; Sandvig, Kirsten

    2016-01-01

    2-fluoro-2-deoxy-D-glucose (FDG), labeled with 18F radioisotope, is the most common imaging agent used for positron emission tomography (PET) in oncology. However, little is known about the cellular effects of FDG. Another glucose analogue, 2-deoxy-D-glucose (2DG), has been shown to affect many cellular functions, including intracellular transport and lipid metabolism, and has been found to improve the efficacy of cancer chemotherapeutic agents in vivo. Thus, in the present study, we have investigated cellular effects of FDG with the focus on changes in cellular lipids and intracellular transport. By quantifying more than 200 lipids from 17 different lipid classes in HEp-2 cells and by analyzing glycosphingolipids from MCF-7, HT-29 and HBMEC cells, we have discovered that FDG treatment inhibits glucosylceramide synthesis and thus reduces cellular levels of glycosphingolipids. In addition, in HEp-2 cells the levels and/or species composition of other lipid classes, namely diacylglycerols, phosphatidic acids and phosphatidylinositols, were found to change upon treatment with FDG. Furthermore, we show here that FDG inhibits retrograde Shiga toxin transport and is much more efficient in protecting cells against the toxin than 2DG. In summary, our data reveal novel effects of FDG on cellular transport and glycosphingolipid metabolism, which suggest a potential clinical application of FDG as an adjuvant for cancer chemotherapy. PMID:27829218

  14. Prenatal Transportation Stress Alters Temperament and Serum Cortisol Concentrations in Suckling Brahman Calves

    USDA-ARS?s Scientific Manuscript database

    This experiment examined the relationship between prenatal stress and subsequent calf temperament through weaning. The prenatal stressor utilized was repeated transportation of pregnant Brahman cows for 2 hours at 60, 80, 100, 120, and 140 days of gestation. Prenatally stressed calves (n = 41) were ...

  15. Inhibition of Nucleotide Sugar Transport in Trypanosoma brucei Alters Surface Glycosylation*

    PubMed Central

    Liu, Li; Xu, Yu-Xin; Caradonna, Kacey L.; Kruzel, Emilia K.; Burleigh, Barbara A.; Bangs, James D.; Hirschberg, Carlos B.

    2013-01-01

    Nucleotide sugar transporters (NSTs) are indispensible for the biosynthesis of glycoproteins by providing the nucleotide sugars needed for glycosylation in the lumen of the Golgi apparatus. Mutations in NST genes cause human and cattle diseases and impaired cell walls of yeast and fungi. Information regarding their function in the protozoan parasite, Trypanosoma brucei, a causative agent of African trypanosomiasis, is unknown. Here, we characterized the substrate specificities of four NSTs, TbNST1–4, which are expressed in both the insect procyclic form (PCF) and mammalian bloodstream form (BSF) stages. TbNST1/2 transports UDP-Gal/UDP-GlcNAc, TbNST3 transports GDP-Man, and TbNST4 transports UDP-GlcNAc, UDP-GalNAc, and GDP-Man. TbNST4 is the first NST shown to transport both pyrimidine and purine nucleotide sugars and is demonstrated here to be localized at the Golgi apparatus. RNAi-mediated silencing of TbNST4 in the procyclic form caused underglycosylated surface glycoprotein EP-procyclin. Similarly, defective glycosylation of the variant surface glycoprotein (VSG221) as well as the lysosomal membrane protein p67 was observed in Δtbnst4 BSF T. brucei. Relative infectivity analysis showed that defects in glycosylation of the surface coat resulting from tbnst4 deletion were insufficient to impact the ability of this parasite to infect mice. Notably, the fact that inactivation of a single NST gene results in measurable defects in surface glycoproteins in different life cycle stages of the parasite highlights the essential role of NST(s) in glycosylation of T. brucei. Thus, results presented in this study provide a framework for conducting functional analyses of other NSTs identified in T. brucei. PMID:23443657

  16. Application of a pore-scale reactive transport model to a natural analog for reaction-induced pore alterations

    DOE PAGES

    Yoon, Hongkyu; Major, Jonathan; Dewers, Thomas; ...

    2017-01-05

    Dissolved CO2 in the subsurface resulting from geological CO2 storage may react with minerals in fractured rocks, confined aquifers, or faults, resulting in mineral precipitation and dissolution. The overall rate of reaction can be affected by coupled processes including hydrodynamics, transport, and reactions at the (sub) pore-scale. In this work pore-scale modeling of coupled fluid flow, reactive transport, and heterogeneous reactions at the mineral surface is applied to account for permeability alterations caused by precipitation-induced pore-blocking. This paper is motivated by observations of CO2 seeps from a natural CO2 sequestration analog, Crystal Geyser, Utah. Observations along the surface exposure ofmore » the Little Grand Wash fault indicate the lateral migration of CO2 seep sites (i.e., alteration zones) of 10–50 m width with spacing on the order of ~100 m over time. Sandstone permeability in alteration zones is reduced by 3–4 orders of magnitude by carbonate cementation compared to unaltered zones. One granular porous medium and one fracture network systems are used to conceptually represent permeable porous media and locations of conduits controlled by fault-segment intersections and/or topography, respectively. Simulation cases accounted for a range of reaction regimes characterized by the Damköhler (Da) and Peclet (Pe) numbers. Pore-scale simulation results demonstrate that combinations of transport (Pe), geochemical conditions (Da), solution chemistry, and pore and fracture configurations contributed to match key patterns observed in the field of how calcite precipitation alters flow paths by pore plugging. This comparison of simulation results with field observations reveals mechanistic explanations of the lateral migration and enhances our understanding of subsurface processes associated with the CO2 injection. In addition, permeability and porosity relations are constructed from pore-scale simulations which account for a range of

  17. Caffeine alters glutamate-aspartate transporter function and expression in rat retina.

    PubMed

    de Freitas, Adriana Pinto; Ferreira, Danielle Dias Pinto; Fernandes, Arlete; Martins, Robertta Silva; Borges-Martins, Vladimir Pedro Peralva; Sathler, Matheus Figueiredo; Dos-Santos-Pereira, Maurício; Paes-de-Carvalho, Roberto; Giestal-de-Araujo, Elizabeth; de Melo Reis, Ricardo Augusto; Kubrusly, Regina Celia Cussa

    2016-11-19

    l-Glutamate and l-aspartate are the main excitatory amino acids (EAAs) in the Central Nervous System (CNS) and their uptake regulation is critical for the maintenance of the excitatory balance. Excitatory amino acid transporters (EAATs) are widely distributed among central neurons and glial cells. GLAST and GLT1 are expressed in glial cells, whereas excitatory amino acid transporter 3/excitatory amino acid carrier 1 (EAAT3/EAAC1) is neuronal. Different signaling pathways regulate glutamate uptake by modifying the activity and expression of EAATs. In the present work we show that immature postnatal day 3 (PN3) rat retinas challenged by l-glutamate release [(3)H]-d-Aspartate linked to the reverse transport, with participation of NMDA, but not of non-NMDA receptors. The amount of [(3)H]-d-Aspartate released by l-glutamate is reduced during retinal development. Moreover, immature retinae at PN3 and PN7, but not PN14, exposed to a single dose of 200 or 500μM caffeine or the selective A2A receptor (A2AR) antagonist 100nM ZM241385 decreased [(3)H]-d-Aspartate uptake. Caffeine also selectively increased total expression of EAAT3 at PN7 and its expression in membrane fractions. However, both EAAT1 and EAAT2 were reduced after caffeine treatment in P2 fraction. Addition of 100nM DPCPX, an A1 receptor (A1R) antagonist, had no effect on the [(3)H]-d-Aspartate uptake. [(3)H]-d-Aspartate release was dependent on both extracellular sodium and Dl-TBOA, but not calcium, implying a transporter-mediated mechanism. Our results suggest that in the developing rat retina caffeine modulates [(3)H]-d-Aspartate uptake by blocking adenosine A2AR.

  18. Dampened Amphetamine-Stimulated Behavior and Altered Dopamine Transporter Function in the Absence of Brain GDNF.

    PubMed

    Kopra, Jaakko J; Panhelainen, Anne; Af Bjerkén, Sara; Porokuokka, Lauriina L; Varendi, Kärt; Olfat, Soophie; Montonen, Heidi; Piepponen, T Petteri; Saarma, Mart; Andressoo, Jaan-Olle

    2017-02-08

    Midbrain dopamine neuron dysfunction contributes to various psychiatric and neurological diseases, including drug addiction and Parkinson's disease. Because of its well established dopaminotrophic effects, the therapeutic potential of glial cell line-derived neurotrophic factor (GDNF) has been studied extensively in various disorders with disturbed dopamine homeostasis. However, the outcomes from preclinical and clinical studies vary, highlighting a need for a better understanding of the physiological role of GDNF on striatal dopaminergic function. Nevertheless, the current lack of appropriate animal models has limited this understanding. Therefore, we have generated novel mouse models to study conditional Gdnf deletion in the CNS during embryonic development and reduction of striatal GDNF levels in adult mice via AAV-Cre delivery. We found that both of these mice have reduced amphetamine-induced locomotor response and striatal dopamine efflux. Embryonic GDNF deletion in the CNS did not affect striatal dopamine levels or dopamine release, but dopamine reuptake was increased due to increased levels of both total and synaptic membrane-associated dopamine transporters. Collectively, these results suggest that endogenous GDNF plays an important role in regulating the function of dopamine transporters in the striatum.SIGNIFICANCE STATEMENT Delivery of ectopic glial cell line-derived neurotrophic factor (GDNF) promotes the function, plasticity, and survival of midbrain dopaminergic neurons, the dysfunction of which contributes to various neurological and psychiatric diseases. However, how the deletion or reduction of GDNF in the CNS affects the function of dopaminergic neurons has remained unknown. Using conditional Gdnf knock-out mice, we found that endogenous GDNF affects striatal dopamine homeostasis and regulates amphetamine-induced behaviors by regulating the level and function of dopamine transporters. These data regarding the physiological role of GDNF are

  19. Epigenetics of colorectal cancer.

    PubMed

    Goel, Ajay; Boland, C Richard

    2012-12-01

    In the early years of the molecular biology revolution, cancer research was mainly focused on genetic changes (ie, those that altered DNA sequences). Although this has been extremely useful as our understanding of the pathogenesis and biology of cancer has grown and matured, there is another realm in tumor development that does not involve changing the sequence of cellular DNA. This field is called "epigenetics" and broadly encompasses changes in the methylation of cytosines in DNA, changes in histone and chromatin structure, and alterations in the expression of microRNAs, which control the stability of many messenger RNAs and serve as "master regulators" of gene expression. This review focuses on the epigenetics of colorectal cancer and illustrates the impact epigenetics has had on this field.

  20. Lesion-Induced Alterations in Astrocyte Glutamate Transporter Expression and Function in the Hippocampus

    PubMed Central

    Schreiner, Alexandra E.; Langer, Julia; Kafitz, Karl W.; Rose, Christine R.

    2013-01-01

    Astrocytes express the sodium-dependent glutamate transporters GLAST and GLT-1, which are critical to maintain low extracellular glutamate concentrations. Here, we analyzed changes in their expression and function following a mechanical lesion in the CA1 area of organotypic hippocampal slices. 6-7 days after lesion, a glial scar had formed along the injury site, containing strongly activated astrocytes with increased GFAP and S100β immunoreactivity, enlarged somata, and reduced capability for uptake of SR101. Astrocytes in the scar's periphery were swollen as well, but showed only moderate upregulation of GFAP and S100β and efficiently took up SR101. In the scar, clusters of GLT-1 and GLAST immunoreactivity colocalized with GFAP-positive fibers. Apart from these, GLT-1 immunoreactivity declined with increasing distance from the scar, whereas GLAST expression appeared largely uniform. Sodium imaging in reactive astrocytes indicated that glutamate uptake was strongly reduced in the scar but maintained in the periphery. Our results thus show that moderately reactive astrocytes in the lesion periphery maintain overall glutamate transporter expression and function. Strongly reactive astrocytes in the scar, however, display clusters of GLAST and GLT-1 immunoreactivity together with reduced glutamate transport activity. This reduction might contribute to increased extracellular glutamate concentrations and promote excitotoxic cell damage at the lesion site. PMID:24078881

  1. Extracellular dopamine and alterations on dopamine transporter are related to reserpine toxicity in Caenorhabditis elegans.

    PubMed

    Reckziegel, Patrícia; Chen, Pan; Caito, Sam; Gubert, Priscila; Soares, Félix Alexandre Antunes; Fachinetto, Roselei; Aschner, Michael

    2016-03-01

    Reserpine is used as an animal model of parkinsonism. We hypothesized that the involuntary movements induced by reserpine in rodents are induced by dopaminergic toxicity caused by extracellular dopamine accumulation. The present study tested the effects of reserpine on the dopaminergic system in Caenorhabditis elegans. Reserpine was toxic to worms (decreased the survival, food intake, development and changed egg laying and defecation cycles). In addition, reserpine increased the worms' locomotor rate on food and decreased dopamine levels. Morphological evaluations of dopaminergic CEP neurons confirmed neurodegeneration characterized by decreased fluorescence intensity and the number of worms with intact CEP neurons, and increased number of shrunken somas per worm. These effects were unrelated to reserpine's effect on decreased expression of the dopamine transporter, dat-1. Interestingly, the locomotor rate on food and the neurodegenerative parameters fully recovered to basal conditions upon reserpine withdrawal. Furthermore, reserpine decreased survival in vesicular monoamine transporter and dat-1 loss-of-function mutant worms. In addition, worms pre-exposed to dopamine followed by exposure to reserpine had decreased survival. Reserpine activated gst-4, which controls a phase II detoxification enzymes downstream of nuclear factor (erythroid-derived-2)-like 2. Our findings establish that the dopamine transporter, dat-1, plays an important role in reserpine toxicity, likely by increasing extracellular dopamine concentrations.

  2. SGLT2 inhibitor lowers serum uric acid through alteration of uric acid transport activity in renal tubule by increased glycosuria.

    PubMed

    Chino, Yukihiro; Samukawa, Yoshishige; Sakai, Soichi; Nakai, Yasuhiro; Yamaguchi, Jun-ichi; Nakanishi, Takeo; Tamai, Ikumi

    2014-10-01

    Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UE(UA)) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UE(UA), suggesting that SUA decreased as a result of the increase in the UE(UA). The increase in UE(UA) was correlated with an increase in urinary D-glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UE(UA) is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and D-glucose. It was observed that the efflux of [(14) C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans-stimulated by 10 mm D-glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [(14) C]UA by oocytes was cis-inhibited by 100 mm D-glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UE(UA) could potentially be increased by luseogliflozin-induced glycosuria, with alterations of UA transport activity because of urinary glucose.

  3. SGLT2 inhibitor lowers serum uric acid through alteration of uric acid transport activity in renal tubule by increased glycosuria

    PubMed Central

    Chino, Yukihiro; Samukawa, Yoshishige; Sakai, Soichi; Nakai, Yasuhiro; Yamaguchi, Jun-ichi; Nakanishi, Takeo; Tamai, Ikumi

    2014-01-01

    Sodium glucose cotransporter 2 (SGLT2) inhibitors have been reported to lower the serum uric acid (SUA) level. To elucidate the mechanism responsible for this reduction, SUA and the urinary excretion rate of uric acid (UEUA) were analysed after the oral administration of luseogliflozin, a SGLT2 inhibitor, to healthy subjects. After dosing, SUA decreased, and a negative correlation was observed between the SUA level and the UEUA, suggesting that SUA decreased as a result of the increase in the UEUA. The increase in UEUA was correlated with an increase in urinary d-glucose excretion, but not with the plasma luseogliflozin concentration. Additionally, in vitro transport experiments showed that luseogliflozin had no direct effect on the transporters involved in renal UA reabsorption. To explain that the increase in UEUA is likely due to glycosuria, the study focused on the facilitative glucose transporter 9 isoform 2 (GLUT9ΔN, SLC2A9b), which is expressed at the apical membrane of the kidney tubular cells and transports both UA and d-glucose. It was observed that the efflux of [14C]UA in Xenopus oocytes expressing the GLUT9 isoform 2 was trans-stimulated by 10 mm d-glucose, a high concentration of glucose that existed under SGLT2 inhibition. On the other hand, the uptake of [14C]UA by oocytes was cis-inhibited by 100 mm d-glucose, a concentration assumed to exist in collecting ducts. In conclusion, it was demonstrated that the UEUA could potentially be increased by luseogliflozin-induced glycosuria, with alterations of UA transport activity because of urinary glucose. PMID:25044127

  4. Chemical transport during formation and alteration of Martian impact and volcanic deposits

    NASA Technical Reports Server (NTRS)

    Newsom, H. E.

    1992-01-01

    Much of the surface of Mars, including volcanic and cratered terrains, probably experienced alteration and degassing processes. These processes may have depleted or enriched many important elements in surface materials, including bedrock, dust, and soils. The composition of the martian soil may represent the best estimate, for some elements, of the average composition of the martian crust, similar to the composition of loess created by glacial action on the Earth. The martian soil may represent the only convenient, globally or regionally averaged sample of the martian crust. In order to understand the composition of the source material for the soil, however, we need to understand the contributions of volcanic vs. impact sources for this material and the chemical fractionations involved in its production. The processes to be addressed include degassing of volcanic deposits, as observed in the Valley of Ten Thousand Smokes at Katmai, Alaska, and degassing of meltbearing impact ejecta as inferred for suevite ejecta sheets at the Ries Crater, and alteration or palagonitization of volcanic deposits, as documented for volcanos in British Columbia and many other volcanic terrains, and impact crater deposits. The process of palagonitization has been the subject of several studies with reference to Mars, and palagonite is a good analogue for the spectroscopic properties of the martian dust. The role of impact in cratering has not been as well studied, although other researchers have established that both degassing and alteration are common features of impact crater deposits. Other relevant sources of experimental data include the extensive literature on the corrosion of nuclear waste glass and leaching of shocked materials.

  5. Chemical transport during formation and alteration of Martian impact and volcanic deposits

    NASA Technical Reports Server (NTRS)

    Newsom, H. E.

    1992-01-01

    Much of the surface of Mars, including volcanic and cratered terrains, probably experienced alteration and degassing processes. These processes may have depleted or enriched many important elements in surface materials, including bedrock, dust, and soils. The composition of the martian soil may represent the best estimate, for some elements, of the average composition of the martian crust, similar to the composition of loess created by glacial action on the Earth. The martian soil may represent the only convenient, globally or regionally averaged sample of the martian crust. In order to understand the composition of the source material for the soil, however, we need to understand the contributions of volcanic vs. impact sources for this material and the chemical fractionations involved in its production. The processes to be addressed include degassing of volcanic deposits, as observed in the Valley of Ten Thousand Smokes at Katmai, Alaska, and degassing of meltbearing impact ejecta as inferred for suevite ejecta sheets at the Ries Crater, and alteration or palagonitization of volcanic deposits, as documented for volcanos in British Columbia and many other volcanic terrains, and impact crater deposits. The process of palagonitization has been the subject of several studies with reference to Mars, and palagonite is a good analogue for the spectroscopic properties of the martian dust. The role of impact in cratering has not been as well studied, although other researchers have established that both degassing and alteration are common features of impact crater deposits. Other relevant sources of experimental data include the extensive literature on the corrosion of nuclear waste glass and leaching of shocked materials.

  6. Monocarboxylate transporter 8 deficiency: altered thyroid morphology and persistent high triiodothyronine/thyroxine ratio after thyroidectomy.

    PubMed

    Wirth, Eva K; Sheu, Sien-Yi; Chiu-Ugalde, Jazmin; Sapin, Remy; Klein, Marc O; Mossbrugger, Ilona; Quintanilla-Martinez, Leticia; de Angelis, Martin Hrabĕ; Krude, Heiko; Riebel, Thomas; Rothe, Karin; Köhrle, Josef; Schmid, Kurt W; Schweizer, Ulrich; Grüters, Annette

    2011-10-01

    Thyroid hormone transport across the plasma membrane depends on transmembrane transport proteins, including monocarboxylate transporter 8 (MCT8). Mutations in MCT8 (or SLC16A2) lead to a severe form of X-linked psychomotor retardation, which is characterised by elevated plasma triiodothyronine (T(3)) and low/normal thyroxine (T(4)). MCT8 contributes to hormone release from the thyroid gland. To characterise the potential impact of MCT8-deficiency on thyroid morphology in a patient and in Mct8-deficient mice. Thyroid morphology in a patient carrying the A224V mutation was followed by ultrasound imaging for over 10 years. After thyroidectomy, a histopathological analysis was carried out. The findings were compared with histological analyses of mouse thyroids from the Mct8(-/y) model. We show that an inactivating mutation in MCT8 leads to a unique, progressive thyroid follicular pathology in a patient. After thyroidectomy, histological analysis revealed gross morphological changes, including several hyperplastic nodules, microfollicular areas with stromal fibrosis and a small focus of microfollicular structures with nuclear features reminiscent of papillary thyroid carcinoma (PTC). These findings are supported by an Mct8-null mouse model in which we found massive papillary hyperplasia in 6- to 12-month-old mice and nuclear features consistent with PTC in almost 2-year-old animals. After complete thyroidectomy and substitution with levothyroxine (l-T(4)), the preoperative, inadequately low T(4) and free T(4) remained, while increasing the l-T(4) dosage led to T(3) serum concentrations above the normal range. Our results implicate peripheral deiodination in the peculiar hormonal constellation of MCT8-deficient patients. Other MCT8-deficient patients should be closely monitored for potential thyroid abnormalities.

  7. Altered interregional molecular associations of the serotonin transporter in attention deficit/hyperactivity disorder assessed with PET.

    PubMed

    Vanicek, Thomas; Kutzelnigg, Alexandra; Philippe, Cecile; Sigurdardottir, Helen L; James, Gregory M; Hahn, Andreas; Kranz, Georg S; Höflich, Anna; Kautzky, Alexander; Traub-Weidinger, Tatjana; Hacker, Marcus; Wadsak, Wolfgang; Mitterhauser, Markus; Kasper, Siegfried; Lanzenberger, Rupert

    2017-02-01

    Altered serotonergic neurotransmission has been found to cause impulsive and aggressive behavior, as well as increased motor activity, all exemplifying key symptoms of ADHD. The main objectives of this positron emission tomography (PET) study were to investigate the serotonin transporter binding potential (SERT BPND ) in patients with ADHD and to assess associations of SERT BPND between the brain regions. 25 medication-free patients with ADHD (age ± SD; 32.39 ± 10.15; 10 females) without any psychiatric comorbidity and 25 age and sex matched healthy control subjects (33.74 ± 10.20) were measured once with PET and the highly selective and specific radioligand [(11) C]DASB. SERT BPND maps in nine a priori defined ROIs exhibiting high SERT binding were compared between groups by means of a linear mixed model. Finally, adopted from structural and functional connectivity analyses, we performed correlational analyses using regional SERT binding potentials to examine molecular interregional associations between all selected ROIs. We observed significant differences in the interregional correlations between the precuneus and the hippocampus in patients with ADHD compared to healthy controls, using SERT BPND of the investigated ROIs (P < 0.05; Bonferroni corrected). When correlating SERT BPND and age in the ADHD and the healthy control group, we confirmed an age-related decline in brain SERT binding in the thalamus and insula (R(2)  = 0.284, R(2)  = 0.167, Ps < 0.05; Bonferroni corrected). The results show significantly different interregional molecular associations of the SERT expression for the precuneus with hippocampus in patients with ADHD, indicating presumably altered functional coupling. Altered interregional coupling between brain regions might be a sensitive approach to demonstrate functional and molecular alterations in psychiatric conditions. Hum Brain Mapp 38:792-802, 2017. © 2016 Wiley Periodicals, Inc.

  8. Evidence for altered ion transport in Saccharomyces cerevisiae overexpressing human MDR 1 protein.

    PubMed

    Fritz, F; Howard, E M; Hoffman, M M; Roepe, P D

    1999-03-30

    Recently [Hoffman, M. M., and Roepe, P. D. (1997) Biochemistry 36, 11153-11168] we presented evidence for a novel Na+- and Cl--dependent H+ transport process in LR73/hu MDR 1 CHO transfectants that likely explains pHi, volume, and membrane potential changes in eukaryotic cells overexpressing the hu MDR 1 protein. To further explore this process, we have overexpressed human MDR 1 protein in yeast strain 9.3 following a combination of approaches used previously [Kuchler, K., and Thorner, J. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 2302-2306; Ruetz, S., et al. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 11588-11592]. Thus, a truncated hu MDR 1 cDNA was cloned behind a tandem array of sterile 6 (Ste6) and alchohol dehydrogenase (Adh) promoters to create the yeast expression vector pFF1. Valinomycin resistance of intact cells and Western blot analysis with purified yeast plasma membranes confirmed the overexpression of full length, functional, and properly localized hu MDR 1 protein in independently isolated 9.3/pFF1 colonies. Interestingly, relative valinomycin resistance and growth of the 9.3/hu MDR 1 strains are found to strongly depend on the ionic composition of the growth medium. Atomic absorption reveals significant differences in intracellular K+ for 9.3/hu MDR 1 versus control yeast. Transport assays using [3H]tetraphenylphosphonium ([3H]TPP+) reveal perturbations in membrane potential for 9.3/hu MDR 1 yeast that are stimulated by KCl and alkaline pHex. ATPase activity of purified plasma membrane fractions from yeast strains and LR73/hu MDR 1 CHO transfectants constructed previously [Hoffman, M. M., et al. (1996) J. Gen. Physiol. 108, 295-313] was compared. MDR 1 ATPase activity exhibits a higher pH optimum and different salt dependencies, relative to yeast H+ ATPase. Inside-out plasma membrane vesicles (ISOV) fabricated from 9.3/hu MDR 1 and control strains were analyzed for formation of H+ gradients +/- verapamil. Similar pharmacologic profiles are found for

  9. Keratins in colorectal epithelial function and disease

    PubMed Central

    Majumdar, Debabrata; Tiernan, James P; Lobo, Alan J; Evans, Caroline A; Corfe, Bernard M

    2012-01-01

    Keratins are the largest subgroup of intermediate filament proteins, which are an important constituent of the cellular cytoskeleton. The principally expressed keratins (K) of the intestinal epithelium are K8, K18 and K19. The specific keratin profile of a particular epithelium provides it with strength and integrity. In the colon, keratins have been shown to regulate electrolyte transport, likely by targeting ion transporters to their correct location in the colonocytes. Keratins are highly dynamic and are subject to post-translational modifications including phosphorylation, acetylation and glycosylation. These affect the filament dynamics and hence solubility of keratins and may contribute to protection against degradation. Keratin null mice (K8−/−) develop colitis, and abnormal keratin mutations have been shown to be associated with inflammatory bowel disease (IBD). Abnormal expression of K7 and K20 has been noted in colitis-associated dysplasia and cancers. In sporadic colorectal cancers (CRCs) may be useful in predicting tumour prognosis; a low K20 expression is noted in CRCs with high microsatellite instability; and keratins have been noted as dysregulated in peri-adenomatous fields. Caspase-cleaved fragment of K18 (M30) in the serum of patients with CRC has been used as a marker of cancer load and to assess response to therapy. These data suggest an emerging importance of keratins in maintaining normal function of the gastrointestinal epithelium as well as being a marker of various colorectal diseases. This review will primarily focus on the biology of these proteins, physiological functions and alterations in IBD and CRCs. PMID:22974212

  10. Oncogenic RAS alters the global and gene-specific histone modification pattern during epithelial-mesenchymal transition in colorectal carcinoma cells.

    PubMed

    Peláez, Ignacio Mazón; Kalogeropoulou, Margarita; Ferraro, Angelo; Voulgari, Angeliki; Pankotai, Tibor; Boros, Imre; Pintzas, Alexander

    2010-06-01

    The presence of different forms of histone covalent modifications, such as phosphorylation, acetylation and methylation in localized promoter regions are markers for chromatin packing and transcription. Activation of RAS signalling pathways through oncogenic RAS mutations is a hallmark of colorectal cancer. Overexpression of Harvey-Ras oncogene induces epithelial-mesenchymal transition (EMT) in Caco-2 cells. We focused on the role of epigenetic modifications of histone H3 and its dependence on RAS signal transduction pathways and oncogenic transformation. Using cell lines stably overexpressing oncogenic Harvey-RAS with EMT phenotype, we studied the acquired changes in the H3 histone modification patterns. Two genes show inverse protein expression patterns after Ha-RAS overexpression: Cyclin D1, a cell cycle-related gene, and the EMT marker-gene E-cadherin. We report that these two genes demonstrate matching inverse histone repression patterns on their promoter, while histone markers associated with an active state of genes were affected by the RAS-activated signalling pathway MEK-ERK-MSK1. Furthermore, we show that though the level of methyltransferases enzymes was increased, the status of H3 three-methylation at lysine 27 (H3K27me(3)), associated with gene repression on the promoter of Cyclin D1, was lower. Together, these results suggest that histone covalent modifications can be affected by oncogenic RAS pathways to regulate the expression of target genes like Cyclin D1 or E-cadherin and that the dynamic balance of opposing histone-modifying enzymes is critical for the regulation of cell proliferation.

  11. Altered localization of choline transporter sites in the mouse hippocampus after prenatal heroin exposure.

    PubMed

    Vatury, Ori; Barg, Jacob; Slotkin, Theodore A; Yanai, Joseph

    2004-03-01

    Prenatal heroin exposure disrupts hippocampal cholinergic synaptic function and related behaviors. Biochemical studies indicate an increase in the number of presynaptic high-affinity choline transporter (HACT) sites, as assessed by [3H]hemicholinium-3 (HC-3) binding. The present study was designed to assess whether this effect involves global upregulation of the transporter, or whether disruption occurs with a specific tempero-spatial distribution. Pregnant mice were given 10mg/kg per day of heroin subcutaneously on gestational days (GD) 9-18. Autoradiographic distribution of HC-3 binding sites was evaluated in the hippocampus of the offspring at postnatal days 15, 25, and 53. These results, suggestive of hippocampal "miswiring," are likely to explain the net impairment of cholinergic synaptic function after prenatal heroin exposure, despite the simultaneous upregulation of both presynaptic cholinergic activity and postsynaptic receptors. Understanding the subregional selectivity of hippocampal defects can lead to the development of strategies that may potentially enable therapeutic interventions to offset or reverse the neurobehavioral defects.

  12. Improving Plant Nitrogen Use Efficiency through Alteration of Amino Acid Transport Processes1[OPEN

    PubMed Central

    Perchlik, Molly

    2017-01-01

    Improving the efficiency of nitrogen (N) uptake and utilization in plants could potentially increase crop yields while reducing N fertilization and, subsequently, environmental pollution. Within most plants, N is transported primarily as amino acids. In this study, pea (Pisum sativum) plants overexpressing AMINO ACID PERMEASE1 (AAP1) were used to determine if and how genetic manipulation of amino acid transport from source to sink affects plant N use efficiency. The modified plants were grown under low, moderate, or high N fertilization regimes. The results showed that, independent of the N nutrition, the engineered plants allocate more N via the vasculature to the shoot and seeds and produce more biomass and higher seed yields than wild-type plants. Dependent on the amount of N supplied, the AAP1-overexpressing plants displayed improved N uptake or utilization efficiency, or a combination of the two. They also showed significantly increased N use efficiency in N-deficient as well as in N-rich soils and, impressively, required half the amount of N to produce as many fruits and seeds as control plants. Together, these data support that engineering N allocation from source to sink presents an effective strategy to produce crop plants with improved productivity as well as N use efficiency in a range of N environments. PMID:28733388

  13. Tissue Plasminogen Activator Alters Intracellular Sequestration of Zinc through Interaction with the Transporter ZIP4

    SciTech Connect

    Emmetsberger, Jaime; Mirrione, Martine M.; Zhou, Chun; Fernandez-Monreal, Monica; Siddiq, Mustafa M.; Ji, Kyungmin; Tsirka, Stella E.

    2010-09-17

    Glutamatergic neurons contain free zinc packaged into neurotransmitter-loaded synaptic vesicles. Upon neuronal activation, the vesicular contents are released into the synaptic space, whereby the zinc modulates activity of postsynaptic neurons though interactions with receptors, transporters and exchangers. However, high extracellular concentrations of zinc trigger seizures and are neurotoxic if substantial amounts of zinc reenter the cells via ion channels and accumulate in the cytoplasm. Tissue plasminogen activator (tPA), a secreted serine protease, is also proepileptic and excitotoxic. However, tPA counters zinc toxicity by promoting zinc import back into the neurons in a sequestered form that is nontoxic. Here, we identify the zinc influx transporter, ZIP4, as the pathway through which tPA mediates the zinc uptake. We show that ZIP4 is upregulated after excitotoxin stimulation of the mouse, male and female, hippocampus. ZIP4 physically interacts with tPA, correlating with an increased intracellular zinc influx and lysosomal sequestration. Changes in prosurvival signals support the idea that this sequestration results in neuroprotection. These experiments identify a mechanism via which neurons use tPA to efficiently neutralize the toxic effects of excessive concentrations of free zinc.

  14. Prenatal alcohol exposure alters methyl metabolism and programs serotonin transporter and glucocorticoid receptor expression in brain

    PubMed Central

    Ngai, Ying Fai; Sulistyoningrum, Dian C.; O'Neill, Ryan; Innis, Sheila M.; Weinberg, Joanne

    2015-01-01

    Prenatal alcohol exposure (PAE) programs the fetal hypothalamic-pituitary-adrenal (HPA) axis, resulting in HPA dysregulation and hyperresponsiveness to stressors in adulthood. Molecular mechanisms mediating these alterations are not fully understood. Disturbances in one-carbon metabolism, a source of methyl donors for epigenetic processes, contributes to alcoholic liver disease. We assessed whether PAE affects one-carbon metabolism (including Mtr, Mat2a, Mthfr, and Cbs mRNA) and programming of HPA function genes (Nr3c1, Nr3c2, and Slc6a4) in offspring from ethanol-fed (E), pair-fed (PF), and ad libitum-fed control (C) dams. At gestation day 21, plasma total homocysteine and methionine concentrations were higher in E compared with C dams, and E fetuses had higher plasma methionine concentrations and lower whole brain Mtr and Mat2a mRNA compared with C fetuses. In adulthood (55 days), hippocampal Mtr and Cbs mRNA was lower in E compared with C males, whereas Mtr, Mat2a, Mthfr, and Cbs mRNA were higher in E compared with C females. We found lower Nr3c1 mRNA and lower nerve growth factor inducible protein A (NGFI-A) protein in the hippocampus of E compared with PF females, whereas hippocampal Slc6a4 mRNA was higher in E than C males. By contrast, hypothalamic Slc6a4 mRNA was lower in E males and females compared with C offspring. This was accompanied by higher hypothalamic Slc6a4 mean promoter methylation in E compared with PF females. These findings demonstrate that PAE is associated with alterations in one-carbon metabolism and has long-term and region-specific effects on gene expression in the brain. These findings advance our understanding of mechanisms of HPA dysregulation associated with PAE. PMID:26180184

  15. Prenatal alcohol exposure alters methyl metabolism and programs serotonin transporter and glucocorticoid receptor expression in brain.

    PubMed

    Ngai, Ying Fai; Sulistyoningrum, Dian C; O'Neill, Ryan; Innis, Sheila M; Weinberg, Joanne; Devlin, Angela M

    2015-09-01

    Prenatal alcohol exposure (PAE) programs the fetal hypothalamic-pituitary-adrenal (HPA) axis, resulting in HPA dysregulation and hyperresponsiveness to stressors in adulthood. Molecular mechanisms mediating these alterations are not fully understood. Disturbances in one-carbon metabolism, a source of methyl donors for epigenetic processes, contributes to alcoholic liver disease. We assessed whether PAE affects one-carbon metabolism (including Mtr, Mat2a, Mthfr, and Cbs mRNA) and programming of HPA function genes (Nr3c1, Nr3c2, and Slc6a4) in offspring from ethanol-fed (E), pair-fed (PF), and ad libitum-fed control (C) dams. At gestation day 21, plasma total homocysteine and methionine concentrations were higher in E compared with C dams, and E fetuses had higher plasma methionine concentrations and lower whole brain Mtr and Mat2a mRNA compared with C fetuses. In adulthood (55 days), hippocampal Mtr and Cbs mRNA was lower in E compared with C males, whereas Mtr, Mat2a, Mthfr, and Cbs mRNA were higher in E compared with C females. We found lower Nr3c1 mRNA and lower nerve growth factor inducible protein A (NGFI-A) protein in the hippocampus of E compared with PF females, whereas hippocampal Slc6a4 mRNA was higher in E than C males. By contrast, hypothalamic Slc6a4 mRNA was lower in E males and females compared with C offspring. This was accompanied by higher hypothalamic Slc6a4 mean promoter methylation in E compared with PF females. These findings demonstrate that PAE is associated with alterations in one-carbon metabolism and has long-term and region-specific effects on gene expression in the brain. These findings advance our understanding of mechanisms of HPA dysregulation associated with PAE.

  16. Tuber Physiology and Properties of Starch from Tubers of Transgenic Potato Plants with Altered Plastidic Adenylate Transporter Activity1

    PubMed Central

    Geigenberger, Peter; Stamme, Claudia; Tjaden, Joachim; Schulz, Alexander; Quick, Paul W.; Betsche, Thomas; Kersting, H. J.; Neuhaus, H. Ekkehard

    2001-01-01

    We showed recently that antisense plants with decreased activity of the plastidic ATP/ADP-transporter protein exhibit drastically reduced levels of starch and a decreased amylose/amylopectin ratio, whereas sense plants with increased activity of the transporter possessed more starch than wild-type plants and an increased amylose/amylopectin ratio. In this paper we investigate the effect of altered plastidic ATP/ADP-transporter protein expression on primary metabolism and granule morphology in more detail. Tuber tissues from antisense and sense plants exhibited substantially increased respiratory activity compared with the wild type. Tubers from antisense plants contained markedly increased levels of free sugars, UDP-Glc, and hexose phosphates, whereas phosphoenolpyruvate, isocitrate, ATP, ADP, AMP, UTP, UDP, and inorganic pyrophosphate levels were slightly decreased. In contrast, tubers from sense plants revealed a slight increase in adenine and uridine nucleotides and in the levels of inorganic pyrophosphate, whereas no significant changes in the levels of soluble sugars and metabolites were observed. Antisense tubers contained 50% reduced levels of ADP-Glc, whereas sense tubers contained up to 2-fold increased levels of this sole precursor for starch biosynthesis. Microscopic examination of starch grain morphology revealed that the size of starch grains from antisense tubers was substantially smaller (50%) compared with the wild type. The large starch grains from sense tubers appeared of a more angular morphology, which differed to the more ellipsoid shape of wild type grains. The results suggest a close interaction between plastidial adenylate transport and starch biosynthesis, indicating that ADP-Glc pyrophosphorylase is ATP-limited in vivo and that changes in ADP-Glc concentration determine starch yield, as well as granule morphology. Possible factors linking starch synthesis and respiration are discussed. PMID:11299348

  17. Dynamics of ultrastructural alterations in photosensitized crayfish glial and neuronal cells: Structures involved in transport processes and neuroglial interactions.

    PubMed

    Fedorenko, G M; Fedorenko, Y P; Fedorenko, A G; Uzdensky, A B

    2011-03-01

    Photodynamic therapy (PDT) is used for cancer treatment, including brain tumors. To explore the dynamics of photodynamic injury of glial cells and neurons and corresponding neuroglial interactions, we studied ultrastructure of the PDT-treated crayfish stretch receptor that consists of a single sensory neuron enwrapped by glial cells. Just after PDT, swelling of some mitochondria, dictyosomes, and endoplasmic reticulum cisterns occurred in neurons and glial cells. Tubular lattices involved in intraglial transport became swollen and disintegrated. At 1 hr postirradiation, these alterations were expanded to the whole cells. Segregation of the neuronal cytoplasm by Nissl bodies, which were involved in protein synthesis and transport along neurites, was lost. Swelling of submembrane cisterns prevented formation of glial protrusions and double-wall vesicles involved in the glia-to-neuron transport. Five hours later, glial layers lost organelles, stuck together, or dilated locally as a result of edema. In the neuronal cytoplasm, only demises of ER and swollen mitochondria were present, but few mitochondria retained normal structure. Thus, swelling of intracellular organelles, the first sign of photodynamic injury, occurred simultaneously in neurons and glia, but glial organelles were eliminated more quickly. Therefore, glial cells were less resistant to PDT than neurons. Adjacent glial layers were damaged less than remote ones, suggesting their protection by the neuron. The structures involved in glia-to-neuron (neuronal submembrane cisterns, glial protrusions, double-wall vesicles), intraglial (tubular lattices), and intraneuronal (Nissl bodies, Golgi apparatus, microtubular bundles) transport were impaired at the earlier stages of stretch receptor damage. Copyright © 2010 Wiley-Liss, Inc.

  18. Soluble Conformers of Aβ and Tau Alter Selective Proteins Governing Axonal Transport

    PubMed Central

    Sherman, Mathew A.; LaCroix, Michael; Amar, Fatou; Larson, Megan E.; Forster, Colleen; Aguzzi, Adriano; Bennett, David A.; Ramsden, Martin

    2016-01-01

    Despite the demonstration that amyloid-β (Aβ) can trigger increased tau phosphorylation and neurofibrillary tangle (NFT) formation in vivo, the molecular link associating Aβ and tau pathologies remains ill defined. Here, we observed that exposure of cultured primary neurons to Aβ trimers isolated from brain tissue of subjects with Alzheimer's disease led to a specific conformational change of tau detected by the antibody Alz50. A similar association was supported by postmortem human brain analyses. To study the role of Aβ trimers in vivo, we created a novel bigenic Tg-Aβ+Tau mouse line by crossing Tg2576 (Tg-Aβ) and rTg4510 (Tg-Tau) mice. Before neurodegeneration and amyloidosis, apparent Aβ trimers were increased by ∼2-fold in 3-month-old Tg-Aβ and Tg-Aβ+Tau mice compared with younger mice, whereas soluble monomeric Aβ levels were unchanged. Under these conditions, the expression of soluble Alz50-tau conformers rose by ∼2.2-fold in the forebrains of Tg-Aβ+Tau mice compared with nontransgenic littermates. In parallel, APP accumulated intracellularly, suggestive of a putative dysfunction of anterograde axonal transport. We found that the protein abundance of the kinesin-1 light chain (KLC1) was reduced selectively in vivo and in vitro when soluble Aβ trimers/Alz50-tau were present. Importantly, the reduction in KLC1 was prevented by the intraneuronal delivery of Alz50 antibodies. Collectively, our findings reveal that specific soluble conformers of Aβ and tau cooperatively disrupt axonal transport independently from plaques and tangles. Finally, these results suggest that not all endogenous Aβ oligomers trigger the same deleterious changes and that the role of each assembly should be considered separately. SIGNIFICANCE STATEMENT The mechanistic link between amyloid-β (Aβ) and tau, the two major proteins composing the neuropathological lesions detected in brain tissue of Alzheimer's disease subjects, remains unclear. Here, we report that the

  19. Soluble Conformers of Aβ and Tau Alter Selective Proteins Governing Axonal Transport.

    PubMed

    Sherman, Mathew A; LaCroix, Michael; Amar, Fatou; Larson, Megan E; Forster, Colleen; Aguzzi, Adriano; Bennett, David A; Ramsden, Martin; Lesné, Sylvain E

    2016-09-14

    Despite the demonstration that amyloid-β (Aβ) can trigger increased tau phosphorylation and neurofibrillary tangle (NFT) formation in vivo, the molecular link associating Aβ and tau pathologies remains ill defined. Here, we observed that exposure of cultured primary neurons to Aβ trimers isolated from brain tissue of subjects with Alzheimer's disease led to a specific conformational change of tau detected by the antibody Alz50. A similar association was supported by postmortem human brain analyses. To study the role of Aβ trimers in vivo, we created a novel bigenic Tg-Aβ+Tau mouse line by crossing Tg2576 (Tg-Aβ) and rTg4510 (Tg-Tau) mice. Before neurodegeneration and amyloidosis, apparent Aβ trimers were increased by ∼2-fold in 3-month-old Tg-Aβ and Tg-Aβ+Tau mice compared with younger mice, whereas soluble monomeric Aβ levels were unchanged. Under these conditions, the expression of soluble Alz50-tau conformers rose by ∼2.2-fold in the forebrains of Tg-Aβ+Tau mice compared with nontransgenic littermates. In parallel, APP accumulated intracellularly, suggestive of a putative dysfunction of anterograde axonal transport. We found that the protein abundance of the kinesin-1 light chain (KLC1) was reduced selectively in vivo and in vitro when soluble Aβ trimers/Alz50-tau were present. Importantly, the reduction in KLC1 was prevented by the intraneuronal delivery of Alz50 antibodies. Collectively, our findings reveal that specific soluble conformers of Aβ and tau cooperatively disrupt axonal transport independently from plaques and tangles. Finally, these results suggest that not all endogenous Aβ oligomers trigger the same deleterious changes and that the role of each assembly should be considered separately. The mechanistic link between amyloid-β (Aβ) and tau, the two major proteins composing the neuropathological lesions detected in brain tissue of Alzheimer's disease subjects, remains unclear. Here, we report that the trimeric Aβ species induce

  20. Effect of altered thyroid status on the transport of hepatobiliary radiopharmaceuticals

    SciTech Connect

    Pahuja, D.N.; Noronha, O.P.

    1985-10-01

    The effect of induced hypothyroidism (by feeding an antithyroid drug-propylthiouracil) on the transport and clearance of the routinely used hepatobiliary radiopharmaceuticals--radioiodinated iodine- T (131I) rose bengal and technetium-99m-N-(4-n-butylphenylcarbamoylmethyl) iminodiacetate, was studied in the rats. Hypothyroidism was associated with depressed growth and retarded clearance of these radiotracers from the in vivo system. Treatment of the hypothyroid rats with thyroxine (2-5 micrograms/100 g b.w. day) for 6 wk, restored these parameters towards normal values. These data suggest that delayed clearance of these hepatobiliary tracers could be related to reduced metabolic rate accompanied with the hypotonia and hypomotility of intestine normally observed in the hypothyroid state.

  1. Zinc supplementation of young men alters metallothionein, zinc transporter, and cytokine gene expression in leukocyte populations

    PubMed Central

    Aydemir, Tolunay Beker; Blanchard, Raymond K.; Cousins, Robert J.

    2006-01-01

    An effective measure to assess zinc status of humans has remained elusive, in contrast to iron, where a number of indicators of metabolism/function are available. Using monocytes, T lymphocytes, and granulocytes isolated by magnetic sorting and dried blood spots (DBS) derived from 50 μl of peripheral blood, we evaluated the response of metallothionein (MT), zinc transporter, and cytokine genes to a modest (15 mg of Zn per day) dietary zinc supplement in human subjects. Transcript abundance was measured by quantitative real-time RT-PCR (QRT-PCR). Zinc supplementation increased MT mRNA abundance by up to 2-fold in RNA from leukocyte subsets, and 4-fold in RNA from DBS. Transcript levels for the zinc transporter genes ZnT1 and Zip3 were increased and decreased, respectively, by zinc supplementation. Expression of the ZnT and Zip genes among leukocyte subsets differ by up to 270-fold. Monocytes and granulocytes from supplemented subjects were activated by LPS, whereas T lymphocytes were activated by mimicking antigen presentation. With zinc consumption, TNF-α and IL-1β expression was greater in activated monocytes and granulocytes, and IFN-γ mRNA levels were higher in activated T lymphocytes. These studies show that QRT-PCR is a tool to reliably measure transcript abundance for nutritionally responsive genes in human subjects, and that a small sample of whole dried blood, when appropriately collected, can be used as the source of total RNA for QRT-PCR analysis. The results obtained also show that zinc supplementation of human subjects programs specific leukocytic subsets to show enhanced cytokine expression upon activation by stimulators of immunity. PMID:16434472

  2. ESKIMO1 Disruption in Arabidopsis Alters Vascular Tissue and Impairs Water Transport

    PubMed Central

    Lefebvre, Valérie; Fortabat, Marie-Noëlle; Ducamp, Aloïse; North, Helen M.; Maia-Grondard, Alessandra; Trouverie, Jacques; Boursiac, Yann; Mouille, Gregory; Durand-Tardif, Mylène

    2011-01-01

    Water economy in agricultural practices is an issue that is being addressed through studies aimed at understanding both plant water-use efficiency (WUE), i.e. biomass produced per water consumed, and responses to water shortage. In the model species Arabidopsis thaliana, the ESKIMO1 (ESK1) gene has been described as involved in freezing, cold and salt tolerance as well as in water economy: esk1 mutants have very low evapo-transpiration rates and high water-use efficiency. In order to establish ESK1 function, detailed characterization of esk1 mutants has been carried out. The stress hormone ABA (abscisic acid) was present at high levels in esk1 compared to wild type, nevertheless, the weak water loss of esk1 was independent of stomata closure through ABA biosynthesis, as combining mutant in this pathway with esk1 led to additive phenotypes. Measurement of root hydraulic conductivity suggests that the esk1 vegetative apparatus suffers water deficit due to a defect in water transport. ESK1 promoter-driven reporter gene expression was observed in xylem and fibers, the vascular tissue responsible for the transport of water and mineral nutrients from the soil to the shoots, via the roots. Moreover, in cross sections of hypocotyls, roots and stems, esk1 xylem vessels were collapsed. Finally, using Fourier-Transform Infrared (FTIR) spectroscopy, severe chemical modifications of xylem cell wall composition were highlighted in the esk1 mutants. Taken together our findings show that ESK1 is necessary for the production of functional xylem vessels, through its implication in the laying down of secondary cell wall components. PMID:21408051

  3. The Serotonin Transporter Gene Alters Sensitivity to Attention Bias Modification: Evidence for a Plasticity Gene

    PubMed Central

    Fox, Elaine; Zougkou, Konstantina; Ridgewell, Anna; Garner, Kelly

    2011-01-01

    Background Attention bias modification (ABM) procedures have been shown to modify biased attention with important implications for emotional vulnerability and resilience. The use of ABM to reduce potentially toxic biases, for instance, is a newly emerging therapy for anxiety disorders. A separate line of gene-by-environment interaction research proposes that many so-called vulnerability genes or risk alleles are better seen as plasticity genes, as they seem to make individuals more susceptible to environmental influences for better and for worse. Methods A standard ABM procedure was used with a sample of 116 healthy adults. Participants were randomly assigned to one of two training groups. One received an ABM procedure designed to induce a bias in attention toward negative material, while the other was trained toward positive pictures. Individuals with low- and high-expressing forms of the serotonin transporter gene (5-HTTLPR) were compared. Results Those with a low-expression form (S/S, S/Lg, or Lg/Lg) of the 5-HTTLPR gene developed stronger biases for both negative and positive affective pictures relative to those with the high-expression (La/La) form of the gene. Conclusions Here, we report the first evidence that allelic variation in the promotor region of the 5-HTTLPR gene predicts different degrees of sensitivity to ABM. These results suggest a potential cognitive mechanism for the gene-by-environment interactions that have been found in relation to the serotonin transporter gene. Variation on this genotype may therefore determine who will benefit most (and least) from therapeutic interventions, adversity, and supportive environments. PMID:21840502

  4. The serotonin transporter gene alters sensitivity to attention bias modification: evidence for a plasticity gene.

    PubMed

    Fox, Elaine; Zougkou, Konstantina; Ridgewell, Anna; Garner, Kelly

    2011-12-01

    Attention bias modification (ABM) procedures have been shown to modify biased attention with important implications for emotional vulnerability and resilience. The use of ABM to reduce potentially toxic biases, for instance, is a newly emerging therapy for anxiety disorders. A separate line of gene-by-environment interaction research proposes that many so-called vulnerability genes or risk alleles are better seen as plasticity genes, as they seem to make individuals more susceptible to environmental influences for better and for worse. A standard ABM procedure was used with a sample of 116 healthy adults. Participants were randomly assigned to one of two training groups. One received an ABM procedure designed to induce a bias in attention toward negative material, while the other was trained toward positive pictures. Individuals with low- and high-expressing forms of the serotonin transporter gene (5-HTTLPR) were compared. Those with a low-expression form (S/S, S/Lg, or Lg/Lg) of the 5-HTTLPR gene developed stronger biases for both negative and positive affective pictures relative to those with the high-expression (La/La) form of the gene. Here, we report the first evidence that allelic variation in the promotor region of the 5-HTTLPR gene predicts different degrees of sensitivity to ABM. These results suggest a potential cognitive mechanism for the gene-by-environment interactions that have been found in relation to the serotonin transporter gene. Variation on this genotype may therefore determine who will benefit most (and least) from therapeutic interventions, adversity, and supportive environments. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Altered distributions of nucleocytoplasmic transport-related proteins in the spinal cord of a mouse model of amyotrophic lateral sclerosis.

    PubMed

    Zhang, Jianhua; Ito, Hidefumi; Wate, Reika; Ohnishi, Shizuo; Nakano, Satoshi; Kusaka, Hirofumi

    2006-12-01

    Recent investigations have indicated that the nucleocytoplasmic transport system is essential for maintaining cell viability and cellular functions and that its dysfunction could lead to certain disorders. To investigate the involvement of this system in the pathomechanisms of amyotrophic lateral sclerosis (ALS), we examined the immunohistochemical localization of proteins associated with nucleocytoplasmic transport in the lumbar spinal cord in a mutant SOD1 (G93A) transgenic mouse model of ALS. This model is widely used for ALS research, and the mutant mice are known to exhibit neuronal loss and Lewy body-like hyaline inclusions (LBHIs) in the anterior horns, similar to the pathology seen in familial ALS patients associated with an SOD1 mutation and in several other transgenic rodent models. Using antibodies against the importin beta family of proteins, the major carrier proteins of nucleocytoplasmic transport, and those against their adapter protein, importin alpha, we found that the immunoreactivities were decreased within the nuclei and increased within the cytoplasm of a subset of the surviving anterior horn cells of the transgenic mice. In addition, LBHIs were invariably reactive toward these antibodies. Furthermore, the immunoreactivities for histone H1 and beta-catenin, representative cargo proteins transported by importin beta-dependent and beta-independent nucleocytoplasmic transport pathways, respectively, showed distributions similar to those for importin beta family and importin alpha proteins. The altered distributions of these proteins were not associated with caspase-3 expression, suggesting that the findings are unlikely to be a manifestation of apoptotic processes. Chronological quantitative analysis of importin beta-immunostained sections from the transgenic mice revealed a statistically significant progressive decrease in the proportion of the anterior horn cells exhibiting a more intense reactivity for these proteins in the nucleus than in the

  6. Chemoprevention of colorectal cancer

    PubMed Central

    LANGMAN, M; BOYLE, P

    1998-01-01

    Department of Medicine, Queen Elizabeth Hospital, Birmingham B15 2TH, UK P BOYLE Colorectal cancer is the fourth commonest form of cancer in men with 678 000 estimated new cases per year worldwide, representing 8.9% of all new cancers. The disease is most frequent in Occidental countries and particularly so in North America, Australia, New Zealand, and parts of Europe. Prospects for colorectal cancer control are bright and a number of possible approaches could prove fruitful. Among these, pharmaceutical measures seem to be valid and logical approaches to the prevention of colorectal cancer and diminishing its impact. Such approaches could concentrate in primary prevention in at-risk subjects or be applied in altering the course of precursor or established disease. Treatments used must fulfil basic requirements of biological plausibility and safety in continued use in large numbers of subjects. Those available include vitamins and minerals, and other drugs with potential as antioxidants, immune modulators or promoters of cell differentiation or apoptosis. Of the various regimens suggested, vitamin A supplementation may even predispose to adverse outcomes, and antioxidant vitamins in general have no coherent body of evidence to support their use. N-acetylcysteine and ursodeoxycholic acid have promising characteristics but there are as yet no clinical data to support the use of the former in gut epithelial cancer, and formal dose ranging studies must be carried out before the latter is submitted to large scale trial. Folate shows promising characteristics but non-steroidal anti-inflammatory drugs and vitamin D seem the most promising agents. Both seem to reduce the incidence of disease, and to reduce growth rates and/or induce differentiation or apoptosis in gut epithelial cancer cells. Both are also well understood pharmacologically. They may be preferred to newer selective compounds in the same class until these newer compounds are confirmed as safe for widespread

  7. Prenatal transportation stress alters temperament and serum cortisol concentrations in suckling Brahman calves.

    PubMed

    Littlejohn, B P; Price, D M; Banta, J P; Lewis, A W; Neuendorff, D A; Carroll, J A; Vann, R C; Welsh, T H; Randel, R D

    2016-02-01

    This experiment examined the relationship between prenatal stress and subsequent calf temperament through weaning. The prenatal stressor used was repeated transportation of pregnant Brahman cows for 2 h at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 d of gestation. Prenatally stressed calves ( = 41) were compared with controls ( = 44; dams did not undergo transportation during pregnancy) from 2 wk of age until weaning (average age at weaning = 174.8 ± 1.3 d). Temperament was defined by pen score (PS; 1 = calm and 5 = excitable), exit velocity (EV; m/sec), and temperament score (TS; (PS + EV)/2) and was recorded for each calf on d -168, -140, -112, -84, -56, -28, and 0 relative to weaning (d 0 = weaning). Cortisol concentrations were determined in serum samples obtained on d -168, -140, -28, and 0 relative to weaning. Birth weight and weaning weight were not different between treatment groups ( > 0.1). Pen score was greater ( = 0.03) in prenatally stressed calves (2.84 ± 0.21) relative to controls (2.31 ± 0.21). Exit velocity was greater ( < 0.01) in prenatally stressed calves (2.1 ± 0.14 m/sec) than in controls (1.61 ± 0.14 m/sec). Exit velocity was affected by a treatment × calf sex interaction ( = 0.04) and was greater in prenatally stressed females. Exit velocity was also affected by day ( < 0.0001). Temperament score was greater ( = 0.01) in prenatally stressed calves (2.45 ± 0.16) than in controls (1.95 ± 0.16). Temperament score was affected by day ( < 0.01). Basal cortisol concentrations were greater ( = 0.04) in prenatally stressed calves (15.87 ± 1.04 ng/mL) than in controls (13.42 ± 1.03 ng/mL). Basal cortisol concentrations were greater ( < 0.01) in females (16.61 ± 1.06 ng/mL) than in males (12.68 ± 1.02 ng/mL). Cortisol concentrations were positively correlated ( < 0.01) with PS ( = 0.55, < 0.01), EV ( = 0.4, < 0.01), and TS ( = 0.55, < 0.01). Overall, suckling Brahman calves that were prenatally stressed were more temperamental and

  8. Effects of human alterations on the hydrodynamics and sediment transport in the Sacramento-San Joaquin Delta, California

    USGS Publications Warehouse

    Marineau, Mathieu D.; Wright, Scott A.

    2015-01-01

    The Sacramento-San Joaquin Delta, California, (Delta) has been significantly altered since the mid-nineteenth century. Many existing channels have been widened or deepened and new channels have been created for navigation and water conveyance. Tidal marshes have been drained and leveed to form islands that have subsided, some of which have permanently flooded. To understand how these alterations have affected hydrodynamics and sediment transport in the Delta, we analysed measurements from 27 sites, along with other spatial data, and previous literature. Results show that: (a) the permanent flooding of islands results in an increase in the shear velocity of channels downstream, (b) artificial widening and deepening of channels generally results in a decrease in shear velocity except when the channel is also located downstream of a flooded island, (c) 1.5 Mt/year of sediment was deposited in the Delta (1997–2010), and of this deposited sediment, 0.31 Mt/year (21%) was removed through dredging.

  9. Genetic alterations in fatty acid transport and metabolism genes are associated with metastatic progression and poor prognosis of human cancers.

    PubMed

    Nath, Aritro; Chan, Christina

    2016-01-04

    Reprogramming of cellular metabolism is a hallmark feature of cancer cells. While a distinct set of processes drive metastasis when compared to tumorigenesis, it is yet unclear if genetic alterations in metabolic pathways are associated with metastatic progression of human cancers. Here, we analyzed the mutation, copy number variation and gene expression patterns of a literature-derived model of metabolic genes associated with glycolysis (Warburg effect), fatty acid metabolism (lipogenesis, oxidation, lipolysis, esterification) and fatty acid uptake in >9000 primary or metastatic tumor samples from the multi-cancer TCGA datasets. Our association analysis revealed a uniform pattern of Warburg effect mutations influencing prognosis across all tumor types, while copy number alterations in the electron transport chain gene SCO2, fatty acid uptake (CAV1, CD36) and lipogenesis (PPARA, PPARD, MLXIPL) genes were enriched in metastatic tumors. Using gene expression profiles, we established a gene-signature (CAV1, CD36, MLXIPL, CPT1C, CYP2E1) that strongly associated with epithelial-mesenchymal program across multiple cancers. Moreover, stratification of samples based on the copy number or expression profiles of the genes identified in our analysis revealed a significant effect on patient survival rates, thus confirming prominent roles of fatty acid uptake and metabolism in metastatic progression and poor prognosis of human cancers.

  10. Genetic alterations in fatty acid transport and metabolism genes are associated with metastatic progression and poor prognosis of human cancers

    PubMed Central

    Nath, Aritro; Chan, Christina

    2016-01-01

    Reprogramming of cellular metabolism is a hallmark feature of cancer cells. While a distinct set of processes drive metastasis when compared to tumorigenesis, it is yet unclear if genetic alterations in metabolic pathways are associated with metastatic progression of human cancers. Here, we analyzed the mutation, copy number variation and gene expression patterns of a literature-derived model of metabolic genes associated with glycolysis (Warburg effect), fatty acid metabolism (lipogenesis, oxidation, lipolysis, esterification) and fatty acid uptake in >9000 primary or metastatic tumor samples from the multi-cancer TCGA datasets. Our association analysis revealed a uniform pattern of Warburg effect mutations influencing prognosis across all tumor types, while copy number alterations in the electron transport chain gene SCO2, fatty acid uptake (CAV1, CD36) and lipogenesis (PPARA, PPARD, MLXIPL) genes were enriched in metastatic tumors. Using gene expression profiles, we established a gene-signature (CAV1, CD36, MLXIPL, CPT1C, CYP2E1) that strongly associated with epithelial-mesenchymal program across multiple cancers. Moreover, stratification of samples based on the copy number or expression profiles of the genes identified in our analysis revealed a significant effect on patient survival rates, thus confirming prominent roles of fatty acid uptake and metabolism in metastatic progression and poor prognosis of human cancers. PMID:26725848

  11. Cluster altered magnetic and transport properties in Ge1-x-yMnxEuyTe

    NASA Astrophysics Data System (ADS)

    Kilanski, L.; Górska, M.; Szymczak, R.; Dobrowolski, W.; Podgórni, A.; Avdonin, A.; Domukhovski, V.; Slynko, V. E.; Slynko, E. I.

    2014-08-01

    Magnetic and transport properties of Ge1-x-yMnxEuyTe crystals with chemical compositions 0.041 ≤ x ≤ 0.092 and 0.010 ≤ y ≤ 0.043 are studied. Ferromagnetic order is observed at 150 < T < 160 K. Aggregation of magnetic ions into clusters is found to be the source of almost constant, composition independent Curie temperatures in our samples. Magnetotransport studies show that below 25 K there is a negative magnetoresistance, which is not linear and has a minimum and above 60 K the magnetoresistance is positive and linear. Negative magnetoresistance detected at T < 25 K is found to be due to a tunneling of spin-polarized electrons between ferromagnetic clusters. A linear positive magnetoresistance is identified to be a geometrical effect related to the presence of ferromagnetic clusters inside the semiconductor matrix. The product of the polarization constant (P) and the inter-grain exchange constant (J), JP, varies between about 0.13 meV and 0.99 meV. A strong anomalous Hall effect is observed for T ≤ TC, where TC is the Curie temperature, with coefficients RS independent of temperature. The scaling analysis of the AHE leads to a conclusion that this effect is due to a skew scattering mechanism.

  12. Altered dynein-dependent transport in piRNA pathway mutants

    PubMed Central

    Navarro, Caryn; Bullock, Simon; Lehmann, Ruth

    2009-01-01

    Maintenance of genome integrity in germ cells is crucial for the success of future generations. In Drosophila, and mammals, transposable element activity in the germline can cause DNA breakage and sterility. Recent studies have shown that proteins involved in piRNA (PIWI-interacting RNA) biogenesis are necessary for retrotransposon silencing in the Drosophila germline. Females mutant for genes in the piRNA biogenesis pathway produce eggs with patterning defects that result from Chk-2 (checkpoint kinase-2) DNA damage checkpoint activation. Here we show that large ribonucleoprotein aggregates form in response to DNA damage checkpoint activation in egg chambers of females defective in piRNA biogenesis. Aggregate formation is specific to piRNA biogenesis mutants, as other mutations that activate the same Chk-2-dependent checkpoint do not cause aggregate formation. These aggregates contain components of the dynein motor machinery, retrotransposon RNA, and protein and axial patterning RNAs. Disruption of the aggregates by colcemid treatment leads to increased retrotransposon RNA levels, indicating that these structures may be the destination of retrotransposon RNA transport and may be degradation or sequestration sites. We propose that aggregate formation is a cellular response to protect germ cells from DNA damage caused by elevated retrotransposon expression. PMID:19478063

  13. Alteration of natural (37)Ar activity concentration in the subsurface by gas transport and water infiltration.

    PubMed

    Guillon, Sophie; Sun, Yunwei; Purtschert, Roland; Raghoo, Lauren; Pili, Eric; Carrigan, Charles R

    2016-05-01

    High (37)Ar activity concentration in soil gas is proposed as a key evidence for the detection of underground nuclear explosion by the Comprehensive Nuclear Test-Ban Treaty. However, such a detection is challenged by the natural background of (37)Ar in the subsurface, mainly due to Ca activation by cosmic rays. A better understanding and improved capability to predict (37)Ar activity concentration in the subsurface and its spatial and temporal variability is thus required. A numerical model integrating (37)Ar production and transport in the subsurface is developed, including variable soil water content and water infiltration at the surface. A parameterized equation for (37)Ar production in the first 15 m below the surface is studied, taking into account the major production reactions and the moderation effect of soil water content. Using sensitivity analysis and uncertainty quantification, a realistic and comprehensive probability distribution of natural (37)Ar activity concentrations in soil gas is proposed, including the effects of water infiltration. Site location and soil composition are identified as the parameters allowing for a most effective reduction of the possible range of (37)Ar activity concentrations. The influence of soil water content on (37)Ar production is shown to be negligible to first order, while (37)Ar activity concentration in soil gas and its temporal variability appear to be strongly influenced by transient water infiltration events. These results will be used as a basis for practical CTBTO concepts of operation during an OSI. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Disruption of the ammonium transporter AMT1.1 alters basal defenses generating resistance against Pseudomonas syringae and Plectosphaerella cucumerina

    PubMed Central

    Pastor, Victoria; Gamir, Jordi; Camañes, Gemma; Cerezo, Miguel; Sánchez-Bel, Paloma; Flors, Victor

    2014-01-01

    Disruption of the high-affinity nitrate transporter NRT2.1 activates the priming defense against Pseudomonas syringae, resulting in enhanced resistance. In this study, it is demonstrated that the high-affinity ammonium transporter AMT1.1 is a negative regulator of Arabidopsis defense responses. The T-DNA knockout mutant amt1.1 displays enhanced resistance against Plectosphaerella cucumerina and reduced susceptibility to P. syringae. The impairment of AMT1.1 induces significant metabolic changes in the absence of challenge, suggesting that amt1.1 retains constitutive defense responses. Interestingly, amt1.1 combats pathogens differently depending on the lifestyle of the pathogen. In addition, N starvation enhances the susceptibility of wild type plants and the mutant amt1.1 to P. syringae whereas it has no effect on P. cucumerina resistance. The metabolic changes of amt1.1 against P. syringae are subtler and are restricted to the phenylpropanoid pathway, which correlates with its reduced susceptibility. By contrast, the amt1.1 mutant responds by activating higher levels of camalexin and callose against P. cucumerina. In addition, amt1.1 shows altered levels of aliphatic and indolic glucosinolates and other Trp-related compounds following infection by the necrotroph. These observations indicate that AMT1.1 may play additional roles that affect N uptake and plant immune responses. PMID:24910636

  15. Hepatic alterations are accompanied by changes to bile acid transporter-expressing neurons in the hypothalamus after traumatic brain injury

    PubMed Central

    Nizamutdinov, Damir; DeMorrow, Sharon; McMillin, Matthew; Kain, Jessica; Mukherjee, Sanjib; Zeitouni, Suzanne; Frampton, Gabriel; Bricker, Paul Clint S.; Hurst, Jacob; Shapiro, Lee A.

    2017-01-01

    Annually, there are over 2 million incidents of traumatic brain injury (TBI) and treatment options are non-existent. While many TBI studies have focused on the brain, peripheral contributions involving the digestive and immune systems are emerging as factors involved in the various symptomology associated with TBI. We hypothesized that TBI would alter hepatic function, including bile acid system machinery in the liver and brain. The results show activation of the hepatic acute phase response by 2 hours after TBI, hepatic inflammation by 6 hours after TBI and a decrease in hepatic transcription factors, Gli 1, Gli 2, Gli 3 at 2 and 24 hrs after TBI. Bile acid receptors and transporters were decreased as early as 2 hrs after TBI until at least 24 hrs after TBI. Quantification of bile acid transporter, ASBT-expressing neurons in the hypothalamus, revealed a significant decrease following TBI. These results are the first to show such changes following a TBI, and are compatible with previous studies of the bile acid system in stroke models. The data support the emerging idea of a systemic influence to neurological disorders and point to the need for future studies to better define specific mechanisms of action. PMID:28106051

  16. Evidence for altered polar and lateral auxin transport in the gravity persistent signal (gps) mutants of Arabidopsis.

    PubMed

    Nadella, Vijayanand; Shipp, Matthew J; Muday, Gloria K; Wyatt, Sarah E

    2006-04-01

    Plant shoots do not respond when they are reoriented relative to gravity at 4 degrees C. However, when returned to vertical at room temperature, these organs bend in response to the previous cold gravistimulation. The inflorescence stem of the Arabidopsis thaliana gravity persistent signal (gps) mutants respond abnormally after the cold gravistimulation: gps1 does not bend when returned to room temperature, gps2 bends the wrong way and gps3 over-responds, curving past the predicted angle. In wild type and the mutants, basipetal auxin transport in the inflorescence stem was abolished at 4 degrees C but restored when plants were returned to room temperature. In gps1, auxin transport was increased; in both gps2 and gps3, no significant difference was found when compared to wild type. Expression of the auxin-inducible P(IAA2)::GUS reporter gene, indicated that auxin-induced gene expression was redistributed to the lower side of the inflorescence stem in wild type after gravistimulation at 4 degrees C. In gps1, no asymmetries in P(IAA2)::GUS expression were seen. In gps2, P(IAA2)::GUS expression was localized to the upper side of the stem and in gps3, asymmetric P(IAA2):GUS expression was extended throughout the elongation zone of the inflorescence stem. These results are consistent with altered lateral Indole-3-acetic-acid (IAA) gradients being responsible for the phenotype of each mutant.

  17. Altered Expression and Localization of Ion Transporters Contribute to Diarrhea in Mice With Salmonella-Induced Enteritis

    PubMed Central

    MARCHELLETTA, RONALD R.; GAREAU, MELANIE G.; MCCOLE, DECLAN F.; OKAMOTO, SHARON; ROEL, ELISE; KLINKENBERG, RACHEL; GUINEY, DONALD G.; FIERER, JOSHUA; BARRETT, KIM E.

    2014-01-01

    hyperplasia in Salmonella-infected mice. CONCLUSIONS Salmonella infection induces diarrhea by altering expression and/or function of transporters that mediate water absorption in the colon, likely reflecting the fact that epithelial cells have less time to differentiate into surface cells when proliferation rates are increased by infection. PMID:24001788

  18. Acoustic and sonochemical methods for altering the viscosity of oil during recovery and pipeline transportation.

    PubMed

    Abramov, Vladimir O; Abramova, Anna V; Bayazitov, Vadim M; Mullakaev, Marat S; Marnosov, Alexandr V; Ildiyakov, Alexandr V

    2017-03-01

    Reduction of oil viscosity is of great importance for the petroleum industry since it contributes a lot to the facilitation of pipeline transportation of oil. This study analyzes the capability of acoustic waves to decrease the viscosity of oil during its commercial production. Three types of equipment were tested: an ultrasonic emitter that is located directly in the well and affects oil during its production and two types of acoustic machines to be located at the wellhead and perform acoustic treatment after oil extraction: a setup for ultrasonic hydrodynamic treatment and a flow-through ultrasonic reactor. In our case, the two acoustic machines were rebuilt and tested in the laboratory. The viscosity of oil was measured before and after both types of acoustic treatment; and 2, 24 and 48h after ultrasonic treatment and 1 and 4h after hydrodynamic treatment in order to estimate the constancy of viscosity reduction. The viscosity reduction achieved by acoustic waves was compared to the viscosity reduction achieved by acoustic waves jointly with solvents. It was shown, that regardless of the form of powerful acoustic impact, a long lasting decrease in viscosity can be obtained only if sonochemical treatment is used. Using sonochemical treatment based on ultrasonic hydrodynamic treatment a viscosity reduction by 72,46% was achieved. However, the reduction in viscosity by 16%, which was demonstrated using the ultrasonic downhole tool in the well without addition of chemicals, is high enough to facilitate the production of viscous hydrocarbons. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Epigenetic alteration of the dopamine transporter gene in alcohol-dependent patients is associated with age.

    PubMed

    Nieratschker, Vanessa; Grosshans, Martin; Frank, Josef; Strohmaier, Jana; von der Goltz, Christoph; El-Maarri, Osman; Witt, Stephanie H; Cichon, Sven; Nöthen, Markus M; Kiefer, Falk; Rietschel, Marcella

    2014-03-01

    Chronic alcohol abuse and dependence are associated with dysfunctional dopaminergic neurotransmission in mesocorticolimbic circuits. Genetic and environmental factors have been shown to modulate susceptibility to alcohol dependence, and both may act through epigenetic mechanisms that can modulate gene expression, e.g. DNA methylation at CpG sites. Recent studies have suggested that DNA methylation patterns may change over time. However, few data are available concerning the rate of these changes in specific genes. A recent study found that hypermethylation of the promoter of the dopamine transporter (DAT) gene was positively correlated with alcohol dependence and negatively correlated with alcohol craving. The aim of the present study was to replicate these findings in a larger sample of alcohol-dependent patients and population-based controls matched for age and sex. No difference in methylation level was observed between patients and controls, and no difference in methylation level was observed before and after alcohol withdrawal in patients. However, patients with more severe craving showed a trend towards lower DAT methylation levels (P = 0.07), which is consistent with previous findings. Furthermore, in our overall sample, DAT methylation levels increased with age. Interestingly, a separate analysis of patients suggested that this finding was mainly driven by the patient group. Although the present data do not clarify whether chronic alcohol abuse is responsible for this phenomenon or merely enhances an ageing-specific process, our findings suggest that hypermethylation in alcohol-dependent patients is a consequence, rather than a cause, of the disorder. © 2012 The Authors, Addiction Biology © 2012 Society for the Study of Addiction.

  20. Altered vesicular glutamate transporter distributions in the mouse cochlear nucleus following cochlear insult

    PubMed Central

    Heeringa, Amarins N.; Stefanescu, Roxana A.; Raphael, Yehoash; Shore, Susan E.

    2015-01-01

    Vesicular glutamate transporters 1 and 2 (VGLUT1 and VGLUT2) have distinct distributions in the cochlear nucleus that correspond to the sources of the labeled terminals. VGLUT1 is mainly associated with terminals of auditory nerve fibers, whereas VGLUT2 is mainly associated with glutamatergic terminals deriving from other sources that project to the cochlear nucleus (CN), including somatosensory and vestibular terminals. Previous studies in guinea pig have shown that cochlear damage results in a decrease of VGLUT1-labeled puncta and an increase in VGLUT2-labeled puncta. This indicates cross-modal compensation that is of potential importance in somatic tinnitus. To examine whether this effect is consistent across species and to provide a background for future studies, using transgenesis, the current study examines VGLUT expression profiles upon cochlear insult by intracochlear kanamycin injections in the mouse. Intracochlear kanamycin injections abolished ipsilateral ABR responses in all animals and reduced ipsilateral spiral ganglion neuron densities in animals that were sacrificed after four weeks, but not in animals that were sacrificed after three weeks. In all unilaterally deafened animals, VGLUT1 density was decreased in CN regions that receive auditory nerve fiber terminals, i.e. in the deep layer of the dorsal cochlear nucleus (DCN), in the interstitial region where the auditory nerve enters the CN, and in the magnocellular region of the antero- and posteroventral CN. In contrast, density of VGLUT2 expression was upregulated in the fusiform cell layer of the DCN and in the granule cell lamina, which are known to receive somatosensory and vestibular terminals. These results show that a cochlear insult induces cross-modal compensation in the cochlear nucleus of the mouse, confirming previous findings in guinea pig, and that these changes are not dependent on the occurrence of spiral ganglion neuron degeneration. PMID:26705736

  1. ATP-binding cassette transporter A7 (ABCA7) loss of function alters Alzheimer amyloid processing.

    PubMed

    Satoh, Kanayo; Abe-Dohmae, Sumiko; Yokoyama, Shinji; St George-Hyslop, Peter; Fraser, Paul E

    2015-10-02

    The ATP-binding cassette transporter A7 (ABCA7) has been identified as a susceptibility factor of late onset Alzheimer disease in genome-wide association studies. ABCA7 has been shown to mediate phagocytosis and affect membrane trafficking. The current study examined the impact of ABCA7 loss of function on amyloid precursor protein (APP) processing and generation of amyloid-β (Aβ). Suppression of endogenous ABCA7 in several different cell lines resulted in increased β-secretase cleavage and elevated Aβ. ABCA7 knock-out mice displayed an increased production of endogenous murine amyloid Aβ42 species. Crossing ABCA7-deficient animals to an APP transgenic model resulted in significant increases in the soluble Aβ as compared with mice expressing normal levels of ABCA7. Only modest changes in the amount of insoluble Aβ and amyloid plaque densities were observed once the amyloid pathology was well developed, whereas Aβ deposition was enhanced in younger animals. In vitro studies indicated a more rapid endocytosis of APP in ABCA7 knock-out cells that is mechanistically consistent with the increased Aβ production. These in vitro and in vivo findings indicate a direct role of ABCA7 in amyloid processing that may be associated with its primary biological function to regulate endocytic pathways. Several potential loss-of-function ABCA7 mutations and deletions linked to Alzheimer disease that in some instances have a greater impact than apoE allelic variants have recently been identified. A reduction in ABCA7 expression or loss of function would be predicted to increase amyloid production and that may be a contributing factor in the associated Alzheimer disease susceptibility. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Colorectal Carcinogenesis, Radiation Quality, and the Ubiquitin-Proteasome Pathway

    PubMed Central

    Datta, Kamal; Suman, Shubhankar; Kumar, Santosh; Fornace, Albert J

    2016-01-01

    Adult colorectal epithelium undergoes continuous renewal and maintains homeostatic balance through regulated cellular proliferation, differentiation, and migration. The canonical Wnt signaling pathway involving the transcriptional co-activator β-catenin is important for colorectal development and normal epithelial maintenance, and deregulated Wnt/β-catenin signaling has been implicated in colorectal carcinogenesis. Colorectal carcinogenesis has been linked to radiation exposure, and radiation has been demonstrated to alter Wnt/β-catenin signaling, as well as the proteasomal pathway involved in the degradation of the signaling components and thus regulation of β-catenin. The current review discusses recent progresses in our understanding of colorectal carcinogenesis in relation to different types of radiation and roles that radiation quality plays in deregulating β-catenin and ubiquitin-proteasome pathway (UPP) for colorectal cancer initiation and progression. PMID:26819641

  3. Alteration of the size distributions and mixing states of black carbon through transport in the boundary layer in east Asia

    NASA Astrophysics Data System (ADS)

    Miyakawa, Takuma; Oshima, Naga; Taketani, Fumikazu; Komazaki, Yuichi; Yoshino, Ayako; Takami, Akinori; Kondo, Yutaka; Kanaya, Yugo

    2017-05-01

    Ground-based measurements of black carbon (BC) were performed near an industrial source region in the early summer of 2014 and at a remote island in Japan in the spring of 2015. Here, we report the temporal variations in the transport, size distributions, and mixing states of the BC-containing particles. These particles were characterized using a continuous soot monitoring system, a single particle soot photometer, and an aerosol chemical speciation monitor. The effects of aging on the growth of BC-containing particles were examined by comparing the ground-based observations between the near-source and remote island sites. Secondary formation of sulfate and organic aerosols strongly affected the increases in BC coating (i.e., enhancement of cloud condensation nuclei activity) with air mass aging from the source to the outflow regions. The effects of wet removal on BC microphysics were elucidated by classifying the continental outflow air masses depending on the enhancement ratios of BC to CO (ΔBC / ΔCO), which were used as an indicator of the transport efficiency of BC. It was found that ΔBC / ΔCO ratios were controlled mainly by the wet removal during transport in the planetary boundary layer (PBL) on the timescale of 1-2 days. The meteorological conditions and backward trajectory analyses suggested that air masses strongly affected by wet removal originated mainly from a region in southern China (20-35° N) in the spring of 2015. Removal of large and thickly coated BC-containing particles was detected in the air masses that were substantially affected by the wet removal in the PBL, as predicted by Köhler theory. The size and water solubility of BC-containing particles in the PBL can be altered by the wet removal as well as the condensation of non-BC materials.

  4. Interplay of transporters and enzymes in the Caco-2 cell monolayer: I. effect of altered apical secretion.

    PubMed

    Fan, Jianghong; Maeng, Han-Joo; Pang, K Sandy

    2010-05-01

    Interactions are expected between transporters and enzymes that compete for the substrate within the cell, and controversy exists for data interpretation on the interplay between transporters and enzymes. In the Caco-2 cell monolayer, the increase in mean residence time (MRT) of drug accompanying increased secretion has been construed as the reason for increased metabolism, whereas others hold an opposite view that increased secretion would evoke decreased metabolism in this closed system. A catenary Caco-2 cell model was used to simulate the effects of altered secretion on metabolism, estimated as the fraction of dose metabolized (f(met)) or the extraction ratio (ER). The simulations showed that both f(met) and ER varied inversely with the transporter-mediated intrinsic clearance for apical secretion (CL(int,sec)) under linear conditions. Under non-linear conditions of saturable metabolism, apical absorption, basolateral influx or efflux, the simulated f(met) consistently bore a reciprocal relationship with CL(int,sec). For saturable apical absorption or basolateral efflux, a reciprocal relationship between the ER and CL(int,sec) was also found. However, under conditions of saturable metabolism or basolateral influx, the pattern of change in the ER became dependent on the administration sites, showing increasing patterns for apical dosing but decreasing patterns for basolateral dosing with increasing values of CL(int,sec). In general, f(met) consistently demonstrated an inverse relationship with CL(int,sec), whereas ER, failing to include the drug in the donor side, would not show the same pattern of change in metabolism especially for apical dosing, since a substantial amount of drug was back-secreted into the apical compartment. Copyright (c) 2010 John Wiley & Sons, Ltd.

  5. SLC6A3 coding variant Ala559Val found in two autism probands alters dopamine transporter function and trafficking.

    PubMed

    Bowton, E; Saunders, C; Reddy, I A; Campbell, N G; Hamilton, P J; Henry, L K; Coon, H; Sakrikar, D; Veenstra-VanderWeele, J M; Blakely, R D; Sutcliffe, J; Matthies, H J G; Erreger, K; Galli, A

    2014-10-14

    Emerging evidence associates dysfunction in the dopamine (DA) transporter (DAT) with the pathophysiology of autism spectrum disorder (ASD). The human DAT (hDAT; SLC6A3) rare variant with an Ala to Val substitution at amino acid 559 (hDAT A559V) was previously reported in individuals with bipolar disorder or attention-deficit hyperactivity disorder (ADHD). We have demonstrated that this variant is hyper-phosphorylated at the amino (N)-terminal serine (Ser) residues and promotes an anomalous DA efflux phenotype. Here, we report the novel identification of hDAT A559V in two unrelated ASD subjects and provide the first mechanistic description of its impaired trafficking phenotype. DAT surface expression is dynamically regulated by DAT substrates including the psychostimulant amphetamine (AMPH), which causes hDAT trafficking away from the plasma membrane. The integrity of DAT trafficking directly impacts DA transport capacity and therefore dopaminergic neurotransmission. Here, we show that hDAT A559V is resistant to AMPH-induced cell surface redistribution. This unique trafficking phenotype is conferred by altered protein kinase C β (PKCβ) activity. Cells expressing hDAT A559V exhibit constitutively elevated PKCβ activity, inhibition of which restores the AMPH-induced hDAT A559V membrane redistribution. Mechanistically, we link the inability of hDAT A559V to traffic in response to AMPH to the phosphorylation of the five most distal DAT N-terminal Ser. Mutation of these N-terminal Ser to Ala restores AMPH-induced trafficking. Furthermore, hDAT A559V has a diminished ability to transport AMPH, and therefore lacks AMPH-induced DA efflux. Pharmacological inhibition of PKCβ or Ser to Ala substitution in the hDAT A559V background restores AMPH-induced DA efflux while promoting intracellular AMPH accumulation. Although hDAT A559V is a rare variant, it has been found in multiple probands with neuropsychiatric disorders associated with imbalances in DA neurotransmission

  6. Integrated proteomic and genomic analysis of colorectal cancer

    Cancer.gov

    Investigators who analyzed 95 human colorectal tumor samples have determined how gene alterations identified in previous analyses of the same samples are expressed at the protein level. The integration of proteomic and genomic data, or proteogenomics, pro

  7. Subsurface Transport Over Reactive Multiphases (STORM): A general, coupled, nonisothermal multiphase flow, reactive transport, and porous medium alteration simulator, Version 2 user's guide

    SciTech Connect

    DH Bacon; MD White; BP McGrail

    2000-03-07

    The Hanford Site, in southeastern Washington State, has been used extensively to produce nuclear materials for the US strategic defense arsenal by the Department of Energy (DOE) and its predecessors, the US Atomic Energy Commission and the US Energy Research and Development Administration. A large inventory of radioactive and mixed waste has accumulated in 177 buried single- and double shell tanks. Liquid waste recovered from the tanks will be pretreated to separate the low-activity fraction from the high-level and transuranic wastes. Vitrification is the leading option for immobilization of these wastes, expected to produce approximately 550,000 metric tons of Low Activity Waste (LAW) glass. This total tonnage, based on nominal Na{sub 2}O oxide loading of 20% by weight, is destined for disposal in a near-surface facility. Before disposal of the immobilized waste can proceed, the DOE must approve a performance assessment, a document that described the impacts, if any, of the disposal facility on public health and environmental resources. Studies have shown that release rates of radionuclides from the glass waste form by reaction with water determine the impacts of the disposal action more than any other independent parameter. This report describes the latest accomplishments in the development of a computational tool, Subsurface Transport Over Reactive Multiphases (STORM), Version 2, a general, coupled non-isothermal multiphase flow and reactive transport simulator. The underlying mathematics in STORM describe the rate of change of the solute concentrations of pore water in a variably saturated, non-isothermal porous medium, and the alteration of waste forms, packaging materials, backfill, and host rocks.

  8. Diet and supplements and their impact on colorectal cancer

    PubMed Central

    Pericleous, Marinos; Mandair, Dalvinder

    2013-01-01

    Background Colorectal cancer is the third commonest cancer and the third leading cause of cancer death among men and women. It has been proposed that dietary factors are responsible for 70-90% of colorectal cancer and diet optimization may prevent most cases. Aim To evaluate the role of dietary components and supplements in colorectal cancer. Methods Bibliographical searches were performed in Pubmed for the terms “diet and colorectal cancer”, “diet and colon cancer”, “diet and rectal cancer”, “nutrition and colorectal cancer”, “probiotics and colorectal cancer”, “prebiotics and colorectal cancer”, “alcohol and cancer” and “colorectal cancer epidemiology”. Results Consumption of processed or red meat, especially when cooked at high temperatures may be associated with increased risk of colorectal cancer. The evidence for dietary fibre is unclear but foods that contain high amounts of fibre are usually rich in polyphenols which have been shown to alter molecular processes that can encourage colorectal carcinogenesis. Meta-analyses provide evidence on the benefits of circulating, diet-derived and supplemented, vitamin D and Calcium. We also found that diets rich in Folate may prevent colorectal carcinoma. The evidence on dietary micronutrients such as Zinc and Selenium in association with colorectal cancer is not conclusive. It has been suggested that there may be a direct association between alcohol intake and colorectal cancer. In vitro and in vivo studies have highlighted a possible protective role of prebiotics and probiotics. Conclusions The lack of randomized trials and the presence of confounding factors including smoking, physical activity, obesity and diabetes may often yield inconclusive results. Carefully designed randomized trials are recommended. PMID:24294513

  9. Environmental Effects of Sediment Transport Alteration and Impacts on Protected Species: Edgartown Tidal Energy Project

    SciTech Connect

    Barrett, Stephen B; Schlezinger, David, Ph.D; Cowles, Geoff, Ph.D; Hughes, Patricia; Samimy,; Roland, I; and Terray, E, Ph.D.

    2012-12-29

    and foundation scouring. Woods Hole Oceanographic Institution, cooperating with SMAST, developed an oceanographic model to predict changes in sediment transport as a result of the proposed tidal energy project. Provincetown Center for Coastal Studies prepared background material on protected species - including whales, seals, and sea turtles - in the project area and implemented an initial tagging program to record location specific information on seals and sea turtles. HMMH communicated research plans and findings with local stakeholder groups, state and federal resource agency staff, and the ocean power industry. The information is being used to prepare environmental permit applications and obtain approvals for project construction.

  10. Colorectal Cancer Molecular Biology Moves Into Clinical Practice

    PubMed Central

    Pritchard, Colin C.; Grady, William M.

    2010-01-01

    The promise of personalized medicine is now a clinical reality, with colorectal cancer genetics at the forefront of this next major advance in clinical medicine. This is no more evident than in the recent advances in testing of colorectal cancers for specific molecular alterations in order to guide treatment with the monoclonal antibody therapies cetuximab and panitumumab, which target the epidermal growth factor receptor (EGFR). In this review, we examine genetic mechanisms of colorectal cancer and how these alterations relate to emerging biomarkers for early detection and risk stratification (diagnostic markers), prognosis (prognostic markers), and the prediction of treatment responses (predictive markers). PMID:20921207

  11. Using Reactive Transport Modeling to Understand Formation of the Stimson Sedimentary Unit and Altered Fracture Zones at Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Hausrath, E. M.; Ming, D. W.; Peretyazhko, T.; Rampe, E. B.

    2017-01-01

    Water flowing through sediments at Gale Crater, Mars created environments that were likely habitable, and sampled basin-wide hydrological systems. However, many questions remain about these environments and the fluids that generated them. Measurements taken by the Mars Science Laboratory Curiosity of multiple fracture zones can help constrain the environments that formed them because they can be compared to nearby associated parent material (Figure 1). For example, measurements of altered fracture zones from the target Greenhorn in the Stimson sandstone can be compared to parent material measured in the nearby Big Sky target, allowing constraints to be placed on the alteration conditions that formed the Greenhorn target from the Big Sky target. Similarly, CheMin measurements of the powdered < 150 micron fraction from the drillhole at Big Sky and sample from the Rocknest eolian deposit indicate that the mineralogies are strikingly similar. The main differences are the presence of olivine in the Rocknest eolian deposit, which is absent in the Big Sky target, and the presence of far more abundant Fe oxides in the Big Sky target. Quantifying the changes between the Big Sky target and the Rocknest eolian deposit can therefore help us understand the diagenetic changes that occurred forming the Stimson sedimentary unit. In order to interpret these aqueous changes, we performed reactive transport modeling of 1) the formation of the Big Sky target from a Rocknest eolian deposit-like parent material, and 2) the formation of the Greenhorn target from the Big Sky target. This work allows us to test the relationships between the targets and the characteristics of the aqueous conditions that formed the Greenhorn target from the Big Sky target, and the Big Sky target from a Rocknest eolian deposit-like parent material.

  12. Organic anion transporter 3 (Oat3/Slc22a8) knockout mice exhibit altered clearance and distribution of penicillin G

    PubMed Central

    VanWert, Adam L.; Bailey, Rachel M.; Sweet, Douglas H.

    2010-01-01

    The interaction of renal basolateral organic anion transporter 3 (Oat3) with commonly used pharmacotherapeutics (e.g., NSAIDs, β-lactams, and methotrexate) has been studied extensively in vitro. However, the in vivo role of Oat3 in drug disposition, in the context of other transporters, glomerular filtration, and metabolism, has not been established. Moreover, recent investigations have identified inactive human OAT3 polymorphisms. Therefore, this investigation was designed to elucidate the in vivo role of Oat3 in the disposition of penicillin G and prototypical substrates using an Oat3 knockout mouse model. Oat3 deletion resulted in a doubling of penicillin’s half-life (P < 0.05) and a reduced volume of distribution (P < 0.01), together yielding a plasma clearance that was one-half (P < 0.05, males) to one-third (P < 0.001, females) of that in wild-type mice. Inhibition of Oat3 abolished the differences in penicillin G elimination between genotypes. Hepatic accumulation of penicillin was 2.3 times higher in male knockouts (P < 0.05) and 3.7 times higher in female knockouts (P < 0.001). Female knockouts also exhibited impaired estrone-3-sulfate clearance. Oat3 deletion did not impact p-aminohippurate elimination, providing correlative evidence to studies in Oat1 knockout mice that suggest Oat1 governs tubular uptake of p-aminohippurate. Collectively, these findings are the first to indicate that functional Oat3 is necessary for proper elimination of xenobiotic and endogenous compounds in vivo. Thus Oat3 plays a distinct role in determining the efficacy and toxicity of drugs. Dysfunctional human OAT3 polymorphisms or instances of polypharmacy involving OAT3 substrates may result in altered systemic accumulation of β-lactams and other clinically relevant compounds. PMID:17686950

  13. Gut microbiota imbalance and colorectal cancer

    PubMed Central

    Gagnière, Johan; Raisch, Jennifer; Veziant, Julie; Barnich, Nicolas; Bonnet, Richard; Buc, Emmanuel; Bringer, Marie-Agnès; Pezet, Denis; Bonnet, Mathilde

    2016-01-01

    The gut microbiota acts as a real organ. The symbiotic interactions between resident micro-organisms and the digestive tract highly contribute to maintain the gut homeostasis. However, alterations to the microbiome caused by environmental changes (e.g., infection, diet and/or lifestyle) can disturb this symbiotic relationship and promote disease, such as inflammatory bowel diseases and cancer. Colorectal cancer is a complex association of tumoral cells, non-neoplastic cells and a large amount of micro-organisms, and the involvement of the microbiota in colorectal carcinogenesis is becoming increasingly clear. Indeed, many changes in the bacterial composition of the gut microbiota have been reported in colorectal cancer, suggesting a major role of dysbiosis in colorectal carcinogenesis. Some bacterial species have been identified and suspected to play a role in colorectal carcinogenesis, such as Streptococcus bovis, Helicobacter pylori, Bacteroides fragilis, Enterococcus faecalis, Clostridium septicum, Fusobacterium spp. and Escherichia coli. The potential pro-carcinogenic effects of these bacteria are now better understood. In this review, we discuss the possible links between the bacterial microbiota and colorectal carcinogenesis, focusing on dysbiosis and the potential pro-carcinogenic properties of bacteria, such as genotoxicity and other virulence factors, inflammation, host defenses modulation, bacterial-derived metabolism, oxidative stress and anti-oxidative defenses modulation. We lastly describe how bacterial microbiota modifications could represent novel prognosis markers and/or targets for innovative therapeutic strategies. PMID:26811603

  14. Gut microbiota imbalance and colorectal cancer.

    PubMed

    Gagnière, Johan; Raisch, Jennifer; Veziant, Julie; Barnich, Nicolas; Bonnet, Richard; Buc, Emmanuel; Bringer, Marie-Agnès; Pezet, Denis; Bonnet, Mathilde

    2016-01-14

    The gut microbiota acts as a real organ. The symbiotic interactions between resident micro-organisms and the digestive tract highly contribute to maintain the gut homeostasis. However, alterations to the microbiome caused by environmental changes (e.g., infection, diet and/or lifestyle) can disturb this symbiotic relationship and promote disease, such as inflammatory bowel diseases and cancer. Colorectal cancer is a complex association of tumoral cells, non-neoplastic cells and a large amount of micro-organisms, and the involvement of the microbiota in colorectal carcinogenesis is becoming increasingly clear. Indeed, many changes in the bacterial composition of the gut microbiota have been reported in colorectal cancer, suggesting a major role of dysbiosis in colorectal carcinogenesis. Some bacterial species have been identified and suspected to play a role in colorectal carcinogenesis, such as Streptococcus bovis, Helicobacter pylori, Bacteroides fragilis, Enterococcus faecalis, Clostridium septicum, Fusobacterium spp. and Escherichia coli. The potential pro-carcinogenic effects of these bacteria are now better understood. In this review, we discuss the possible links between the bacterial microbiota and colorectal carcinogenesis, focusing on dysbiosis and the potential pro-carcinogenic properties of bacteria, such as genotoxicity and other virulence factors, inflammation, host defenses modulation, bacterial-derived metabolism, oxidative stress and anti-oxidative defenses modulation. We lastly describe how bacterial microbiota modifications could represent novel prognosis markers and/or targets for innovative therapeutic strategies.

  15. Altered ion transport in normal human bronchial epithelial cells following exposure to chemically distinct metal welding fume particles.

    PubMed

    Fedan, Jeffrey S; Thompson, Janet A; Meighan, Terence G; Zeidler-Erdely, Patti C; Antonini, James M

    2017-07-01

    Welding fume inhalation causes pulmonary toxicity, including susceptibility to infection. We hypothesized that airway epithelial ion transport is a target of fume toxicity, and investigated the effects of fume particulates from manual metal arc-stainless steel (MMA-SS) and gas metal arc-mild steel (GMA-MS) on ion transport in normal human bronchial epithelium (NHBE) cultured in air-interface. MMA-SS particles, more soluble than GMA-MS particles, contain Cr, Ni, Fe and Mn; GMA-MS particles contain Fe and Mn. MMA-SS or GMA-MS particles (0.0167-166.7μg/cm(2)) were applied apically to NHBEs. After 18h transepithelial potential difference (Vt), resistance (Rt), and short circuit current (Isc) were measured. Particle effects on Na(+) and Cl¯ channels and the Na(+),K(+),2Cl¯-cotransporter were evaluated using amiloride (apical), 5-nitro-2-[(3-phenylpropyl)amino]benzoic acid (NPPB, apical), and bumetanide (basolateral), respectively. MMA-SS (0.0167-16.7μg/cm(2)) increased basal Vt. Only 16.7μg/cm(2) GMA-MS increased basal Vt significantly. MMA-SS or GMA-MS exposure potentiated Isc responses (decreases) to amiloride and bumetanide, while not affecting those to NPPB, GMA-MS to a lesser degree than MMA-SS. Variable effects on Rt were observed in response to amiloride, and bumetanide. Generally, MMA-SS was more potent in altering responses to amiloride and bumetanide than GMA-MS. Hyperpolarization occurred in the absence of LDH release, but decreases in Vt, Rt, and Isc at higher fume particulate doses accompanied LDH release, to a greater extent for MMA-SS. Thus, Na(+) transport and Na(+),K(+),2Cl¯-cotransport are affected by fume exposure; MMA-MS is more potent than GMA-MS. Enhanced Na(+) absorption and decreased airway surface liquid could compromise defenses against infection. Published by Elsevier Inc.

  16. Altered ion transport and responsiveness to methacholine and hyperosmolarity in air interface-cultured guinea-pig tracheal epithelium.

    PubMed

    Fedan, Jeffrey S; Wu, David X-Y; Van Scott, Michael R

    2007-01-01

    Challenge of guinea-pig tracheal epithelium with hyperosmolar solution alters ion transport and evokes the release of epithelium-derived relaxing factor (EpDRF). Cultured tracheal epithelial cells (CE) offer the potential to examine biochemical pathways related to EpDRF release, but whether the bioelectric properties and responses of fresh, adherent epithelial cells (FE) are modeled by CE has not been established. Tracheal epithelial cells grown in air-interface culture and fresh tracheal segments were mounted in Ussing chambers to determine short circuit current (I(sc)) and transepithelial resistance (R(t)) and to compare responses to transport inhibitors, methacholine and hyperosmolarity. Significant differences in basal I(sc) and R(t) between FE and CE were observed (I(sc), 41.3+/-3.5 and 8.5+/-0.8 microA/cm(2), P<0.05; R(t), 106+/-7 and 422+/-4 Omega cm(2), P<0.05; respectively); basal spontaneous potential difference values were not different (4.2+/-0.3 and 3.4+/-0.3 mV, respectively). Amiloride (mucosal, 3 x 10(-5) M), bumetanide (basolateral, 10(-5) M) and ouabain (basolateral, 10(-5) M) reduced I(sc) equally in FE and CE. In contrast, NPPB (10(-5) M) in the presence of amiloride had a differential effect, decreasing I(sc) by 11% in FE and 71% in CE (P<0.05). Iberiotoxin (basolateral, 10(-7) M) was without effect in either preparation. In FE, serosal methacholine (3x10(-5) M) elicited an NPPB-insensitive monotonic increase in I(sc), but in CE caused a large, transient, NPPB-inhibitable increase which was followed by an NPPB-resistant plateau. Addition of apical D-mannitol (0.3-267 mosM) to increase osmolarity decreased I(sc) in FE, whereas in CE d-mannitol initially increased (0.3-84.3 mosM) and then decreased (84.3-267 mosM) I(sc). Cell culture causes substantial changes in the bioelectric and pharmacological properties of respiratory epithelium. Caution should be exercised when using CE as a substitute for FE in studies of ion transport- and cell volume

  17. MAPT Genetic Variation and Neuronal Maturity Alter Isoform Expression Affecting Axonal Transport in iPSC-Derived Dopamine Neurons.

    PubMed

    Beevers, Joel E; Lai, Mang Ching; Collins, Emma; Booth, Heather D E; Zambon, Federico; Parkkinen, Laura; Vowles, Jane; Cowley, Sally A; Wade-Martins, Richard; Caffrey, Tara M

    2017-08-08

    The H1 haplotype of the microtubule-associated protein tau (MAPT) locus is genetically associated with neurodegenerative diseases, including Parkinson's disease (PD), and affects gene expression and splicing. However, the functional impact on neurons of such expression differences has yet to be fully elucidated. Here, we employ extended maturation phases during differentiation of induced pluripotent stem cells (iPSCs) into mature dopaminergic neuronal cultures to obtain cultures expressing all six adult tau protein isoforms. After 6 months of maturation, levels of exon 3+ and exon 10+ transcripts approach those of adult brain. Mature dopaminergic neuronal cultures display haplotype differences in expression, with H1 expressing 22% higher levels of MAPT transcripts than H2 and H2 expressing 2-fold greater exon 3+ transcripts than H1. Furthermore, knocking down adult tau protein variants alters axonal transport velocities in mature iPSC-derived dopaminergic neuronal cultures. This work links haplotype-specific MAPT expression with a biologically functional outcome relevant for PD. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Colorectal Cancer

    MedlinePlus

    ... malignant tumor and enter the bloodstream or the lymphatic system where they travel to other organs in the body. Among other things, the lymphatic system transports white blood cells that fight infection. When ...

  19. Multiscale imaging characterization of dopamine transporter knockout mice reveals regional alterations in spine density of medium spiny neurons.

    PubMed

    Berlanga, M L; Price, D L; Phung, B S; Giuly, R; Terada, M; Yamada, N; Cyr, M; Caron, M G; Laakso, A; Martone, M E; Ellisman, M H

    2011-05-16

    The dopamine transporter knockout (DAT KO) mouse is a model of chronic hyperdopaminergia used to study a wide range of neuropsychiatric disorders such as schizophrenia, attention deficit hyperactivity disorder (ADHD), drug abuse, depression, and Parkinson's disease (PD). Early studies characterizing this mouse model revealed a subtle, but significant, decrease in the anterior striatal volume of DAT KO mice accompanied by a decrease in neuronal cell body numbers (Cyr et al., 2005). The present studies were conducted to examine medium spiny neuron (MSN) morphology by extending these earlier reports to include multiscale imaging studies using correlated light microscopy (LM) and electron microscopy (EM) techniques. Specifically, we set out to determine if chronic hyperdopaminergia results in quantifiable or qualitative changes in DAT KO mouse MSNs relative to wild-type (WT) littermates. Using Neurolucida Explorer's morphometric analysis, we measured spine density, dendritic length and synapse number at ages that correspond with the previously reported changes in striatal volume and progressive cell loss. Light microscopic analysis using Neurolucida tracings of photoconverted striatal MSNs revealed a highly localized loss of dendritic spines on the proximal portion of the dendrite (30 μm from the soma) in the DAT KO group. Next, thick sections containing MSN dendritic segments located at a distance of 20-60 μm from the cell soma, a region of the dendrite where spine density is reported to be the highest, were analyzed using electron microscope tomography (EMT). Because of the resolution limits of LM, the EM analysis was an extra measure taken to assure that our analysis included nearly all spines. Spine density measurements collected from the EMT data revealed only a modest decrease in the DAT KO group (n=3 mice) compared to age-matched WT controls (n=3 mice), a trend that supports the LM findings. Finally, a synaptic quantification using unbiased stereology did not

  20. Alterations in Pore-Space Morphology and Hydraulic Properties of Porous Media Resulting From Coupling of Flow and Reactive Transport

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, S.

    2013-12-01

    Environmental remediation approaches often perturb geochemical equilibrium. These perturbations may lead to geochemical transformations, such as precipitation and dissolution of minerals, which in turn can alter the hydraulic properties of the system. If significant changes take place in hydraulic properties, they may have an impact on flow. In short, there exits a feedback effect between flow and geochemical transport processes. There are some challenges associated with modeling the impacts of geochemical transformations on flow. First, the processes of geochemical transformations are best understood at the scale of individual pores. On the other hand, the changes that they cause in hydraulic properties, such as permeability and porosity, are meaningful only on larger scales. Second, it has been demonstrated that effects of geochemical transformations on flow are often threshold-controlled phenomena. For example, there is a critical value of porosity, around which permeability undergoes a sharp change because of a marked change in connectivity. Several gaps currently exist which limit our ability to understand, predict and monitor these emergent, threshold-dominated system transitions. In this presentation, we apply 3D pore network modeling and percolation theory concepts for investigating these threshold-controlled interactions between geochemical transformations and flow. We start with a network model of pores, and an initial distribution of pore radii. We first solve the flow problem using the initial distribution of pore radii. We postulate that the deposition of a mineral in a pore is not tied to the concentration of that mineral in the bulk fluid but to the radius of the pore, with the maximum deposition happening in the smallest pores. In practice, such a network represents a directed or correlated percolation model. A certain fraction of the pores are then assumed blocked (with the smallest pores being blocked first), and we recalculate the macroscopic

  1. Strontium alteration in the Troodos ophiolite: implications for fluid fluxes and geochemical transport in mid-ocean ridge hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Bickle, Mike J.; Teagle, Damon A. H.

    1992-09-01

    New and published strontium isotope analyses from the Troodos ophiolite constrain fluid-solid exchange processes, and the magnitude and circulation paths of the hydrothermal fluids. The 87Sr/ 86Sr profile reflects alteration in the recharge zone of an evolving hydrothermal system. Fluid-rock strontium isotope exchange in the upper ˜ 1.5 km of extrusive lavas was kinetically limited and seawater-derived fluids emitted from the base of this zone were buffered to 87Sr/ 86Sr ratios between ˜ 0.7047 and 0.7059. In contrast, over the next ˜ 1 km depth interval of sheeted dykes and the uppermost plutonics, 87Sr/ 86Sr values cluster about0.7054 ± 7 (2σ) and fluid flow is inferred to have been pervasive with near-equilibrium fluid-rock exchange. Quartz-chlorite and epidosite zones, the probable pathways of the concentrated, high-temperature upwelling fluids, have identical 87Sr/ 86Sr ratios to adjacent diabase dykes. On Troodos a time-integrated fluid flux in excess of2.9 × 10 7 kg m -2 is required to transport the strontium isotope composition of ˜ 0.7054, set in the kinetically controlled exchange zone, through the ˜ 1 km of sheeted dykes and into the zones of concentrated upwelling. The uniformity of the 87Sr/ 86Sr ratios in the diabase sheeted dykes and high-temperature epidosite and quartz-chlorite rocks indicate that the strontium isotopic alteration took place during the high temperature phase of hydrothermal circulation. The inferred minimum time-integrated fluid flux of2.9 × 10 7 kg m -2 substantially exceeds that of˜ 5 × 10 6 kg m -2 inferred from thermal models of high temperature circulation, but is comparable with estimates of the hydrothermal flux from oceanic budgets of 3He, Mg and 87Sr. The high flux estimate for Troodos is consistent with the ophiolite venting fluids, with 87Sr/ 86Sr elevated significantly above rock values, which contrasts with the near-MORB 87Sr/ 86Sr ratios of fluids from active high-temperature vents at mid-ocean ridges and

  2. Polymorphisms in ATP-binding cassette transporter genes and interaction with diet and life style factors in relation to colorectal cancer in a Danish prospective case-cohort study.

    PubMed

    Kopp, Tine Iskov; Andersen, Vibeke; Tjonneland, Anne; Vogel, Ulla

    2015-01-01

    The ATP-binding cassette (ABC) transporter family transports various molecules across the enterocytes in the gut protecting the intestine against potentially harmful substances. Moreover, ABC transporters are involved in mucosal immune defence through interaction with cytokines. The study aimed to assess whether polymorphisms in ABCB1, ABCC2 and ABCG2 were associated with risk of colorectal cancer (CRC) and to investigate gene-environment (dietary factors, smoking and use of non-steroidal anti-inflammatory drugs) and gene-gene interactions between previously studied polymorphisms in IL1B and IL10 and ABC transporter genes in relation to CRC risk. We used a Danish prospective case-cohort study of 1010 CRC cases and 1829 randomly selected participants from the Danish Diet, Cancer and Health cohort. Incidence rate ratios were calculated based on Cox' proportional hazards model. None of the polymorphisms were associated with CRC, but ABCB1 and ABCG2 haplotypes were associated with risk of CRC. ABCB1/rs1045642 interacted with intake of cereals and fiber (p-Value for interaction (P(int)) = 0.001 and 0.01, respectively). In a three-way analysis, both ABCB1/rs1045642 and ABCG2/rs2231137 in combination with IL10/rs3024505 interacted with fiber intake in relation to risk of CRC (P(int) = 0.0007 and 0.009). Our results suggest that the ABC transporters P-glycoprotein/multidrug resistance 1 and BRCP, in cooperation with IL-10, are involved in the biological mechanism underlying the protective effect of fiber intake in relation to CRC. These results should be replicated in other cohorts to rule out chance findings.

  3. Reduced phototropism in pks mutants may be due to altered auxin-regulated gene expression or reduced lateral auxin transport.

    PubMed

    Kami, Chitose; Allenbach, Laure; Zourelidou, Melina; Ljung, Karin; Schütz, Frédéric; Isono, Erika; Watahiki, Masaaki K; Yamamoto, Kotaro T; Schwechheimer, Claus; Fankhauser, Christian

    2014-02-01

    Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  4. Valeriana officinalis does not alter the orofacial dyskinesia induced by haloperidol in rats: role of dopamine transporter.

    PubMed

    Fachinetto, Roselei; Villarinho, Jardel G; Wagner, Caroline; Pereira, Romaiana P; Avila, Daiana Silva; Burger, Marilise E; Calixto, João Batista; Rocha, João B T; Ferreira, Juliano

    2007-10-01

    Chronic treatment with classical neuroleptics in humans can produce a serious side effect, known as tardive dyskinesia (TD). Here, we examined the effects of V. officinalis, a medicinal herb widely used as calming and sleep-promoting, in an animal model of orofacial dyskinesia (OD) induced by long-term treatment with haloperidol. Adult male rats were treated during 12 weeks with haloperidol decanoate (38 mg/kg, i.m., each 28 days) and with V. officinalis (in the drinking water). Vacuous chewing movements (VCMs), locomotor activity and plus maze performance were evaluated. Haloperidol treatment produced VCM in 40% of the treated rats and the concomitant treatment with V. officinalis did not alter either prevalence or intensity of VCMs. The treatment with V. officinalis increased the percentage of the time spent on open arm and the number of entries into open arm in the plus maze test. Furthermore, the treatment with haloperidol and/or V. officinalis decreased the locomotor activity in the open field test. We did not find any difference among the groups when oxidative stress parameters were evaluated. Haloperidol treatment significantly decreased [(3)H]-dopamine uptake in striatal slices and V. officinalis was not able to prevent this effect. Taken together, our data suggest a mechanism involving the reduction of dopamine transport in the maintenance of chronic VCMs in rats. Furthermore, chronic treatment with V. officinalis seems not produce any oxidative damage to central nervous system (CNS), but it also seems to be devoid of action to prevent VCM, at least in the dose used in this study.

  5. Pathophysiological mechanisms of death resistance in colorectal carcinoma

    PubMed Central

    Huang, Ching-Ying; Yu, Linda Chia-Hui

    2015-01-01

    Colon cancers develop adaptive mechanisms to survive under extreme conditions and display hallmarks of unlimited proliferation and resistance to cell death. The deregulation of cell death is a key factor that contributes to chemoresistance in tumors. In a physiological context, balance between cell proliferation and death, and protection against cell damage are fundamental processes for maintaining gut epithelial homeostasis. The mechanisms underlying anti-death cytoprotection and tumor resistance often bear common pathways, and although distinguishing them would be a challenge, it would also provide an opportunity to develop advanced anti-cancer therapeutics. This review will outline cell death pathways (i.e., apoptosis, necrosis, and necroptosis), and discuss cytoprotective strategies in normal intestinal epithelium and death resistance mechanisms of colon tumor. In colorectal cancers, the intracellular mechanisms of death resistance include the direct alteration of apoptotic and necroptotic machinery and the upstream events modulating death effectors such as tumor suppressor gene inactivation and pro-survival signaling pathways. The autocrine, paracrine and exogenous factors within a tumor microenvironment can also instigate resistance against apoptotic and necroptotic cell death in colon cancers through changes in receptor signaling or transporter uptake. The roles of cyclooxygenase-2/prostaglandin E2, growth factors, glucose, and bacterial lipopolysaccharides in colorectal cancer will be highlighted. Targeting anti-death pathways in the colon cancer tissue might be a promising approach outside of anti-proliferation and anti-angiogenesis strategies for developing novel drugs to treat refractory tumors. PMID:26557002

  6. Applications of genomic tools to colorectal cancer therapeutics.

    PubMed

    Auman, J Todd; McLeod, Howard L

    2008-12-01

    Clinically and histopathologically similar colorectal cancers exhibit considerable variability in their responses to chemotherapeutics. The advent of genomic technologies has enabled the unbiased determination of changes in DNA and RNA, alterations that may be responsible for, or predictive of the variability in response to chemotherapy. This review highlights several advances made in applying genomic tools toward colorectal cancer therapeutics. Progress has been made using gene expression profiling to identify which colorectal cancer patients would benefit most from adjuvant chemotherapy. In addition, advances have been made in colorectal cancer pharmacogenomics by identifying gene expression patterns associated with sensitivity to specific chemotherapeutic agents. Lastly, the use of genome-wide mutation screening of individual tumor samples to identify the profiles of mutated genes is explored. Future research toward integrating genomic information with clinical and histopathological data is expected to lead to improved therapeutic management of colorectal cancer.

  7. TRANSPORT

    EPA Science Inventory

    Presentation outline: transport principles, effective solubility; gasoline composition; and field examples (plume diving).
    Presentation conclusions: MTBE transport follows from - phyiscal and chemical properties and hydrology. Field examples show: MTBE plumes > benzene plu...

  8. Colorectal Cancer Screening: Stool DNA and Other Noninvasive Modalities.

    PubMed

    Bailey, James R; Aggarwal, Ashish; Imperiale, Thomas F

    2016-03-01

    Colorectal cancer screening dates to the discovery of precancerous adenomatous tissue. Screening modalities and guidelines directed at prevention and early detection have evolved and resulted in a significant decrease in the prevalence and mortality of colorectal cancer via direct visualization or using specific markers. Despite continued efforts and an overall reduction in deaths attributed to colorectal cancer over the last 25 years, colorectal cancer remains one of the most common causes of malignancy-associated deaths. In attempt to further reduce the prevalence of colorectal cancer and associated deaths, continued improvement in screening quality and adherence remains key. Noninvasive screening modalities are actively being explored. Identification of specific genetic alterations in the adenoma-cancer sequence allow for the study and development of noninvasive screening modalities beyond guaiac-based fecal occult blood testing which target specific alterations or a panel of alterations. The stool DNA test is the first noninvasive screening tool that targets both human hemoglobin and specific genetic alterations. In this review we discuss stool DNA and other commercially available noninvasive colorectal cancer screening modalities in addition to other targets which previously have been or are currently under study.

  9. Prenatal transportation alters the acute phase response (APR) of bull calves exposed to a lipopolysaccharide (LPS) challenge

    USDA-ARS?s Scientific Manuscript database

    This study was designed to determine if prenatal transportation influences the acute phase response (APR) to a postnatal Lipopolysaccharide (LPS) challenge. Pregnant Brahman cows (n=96) matched by age and parity were separated into transported (TRANS; n=48; transported for 2 hours on gestational day...

  10. Colorectal Stents: Current Status

    PubMed Central

    Lee, Jeong-Mi

    2015-01-01

    A self-expandable metal stent (SEMS) is an effective and safe method for the decompression of colon obstruction. Based on recent evidence, colorectal SEMS is now recommended for the palliation of patients with colonic obstruction from incurable colorectal cancer or extracolonic malignancy and also as a bridge to surgery in those who are a high surgical risk. Prophylactic SEMS insertion in patients with no obstruction symptoms is not recommended. Most colorectal SEMS are inserted endoscopically under fluoroscopic guidance. The technical and clinical success rates of colorectal SEMS are high, and the complication rate is acceptable. Advances in this technology will make the insertion of colorectal SEMS better and may expand the indications of colorectal SEMS in the future. PMID:26064818

  11. No association between mitochondrial DNA copy number and colorectal adenomas.

    PubMed

    Thyagarajan, Bharat; Guan, Weihua; Fedirko, Veronika; Barcelo, Helene; Tu, Huakang; Gross, Myron; Goodman, Michael; Bostick, Roberd M

    2016-08-01

    Despite previously reported associations between peripheral blood mtDNA copy number and colorectal cancer, it remains unclear whether altered mtDNA copy number in peripheral blood is a risk factor for colorectal cancer or a biomarker for undiagnosed colorectal cancer. Though colorectal adenomas are well-recognized precursor lesions to colorectal cancer, no study has evaluated an association between mtDNA copy number and colorectal adenoma risk. Hence, we investigated an association between peripheral blood mtDNA copy number and incident, sporadic colorectal adenoma in 412 colorectal adenoma cases and 526 cancer-free controls pooled from three colonoscopy-based case-control studies that used identical methods for case ascertainment, risk factor determination, and biospecimen collection. We also evaluated associations between relative mtDNA copy number and markers of oxidative stress, including circulating F2 -isoprostanes, carotenoids, and fluorescent oxidation products. We measured mtDNA copy number using a quantitative real time polymerase chain reaction (PCR). We used unconditional logistic regression to analyze the association between mtDNA copy number and colorectal adenoma risk after multivariable adjustment. We found no association between logarithmically transformed relative mtDNA copy number, analyzed as a continuous variable, and colorectal adenoma risk (odds ratio = 1.02, 95%CI: 0.82-1.27; P = 0.86). There were no statistically significant associations between relative mtDNA copy number and other markers of oxidative stress. Our findings, taken together with those from previous studies, suggest that relative mtDNA copy number in peripheral blood may more likely be a marker of early colorectal cancer than of risk for the disease or of in vivo oxidative stress. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  12. [Molecular genetics of colorectal cancer and carcinogenesis].

    PubMed

    Panduro Cerda, A; Lima González, G; Villalobos, J J

    1993-01-01

    Genetic and environmental aspects play an important role in the development of colorectal cancer. However, the common molecular alteration in both hereditary and sporadic colon cancer is localized in the APC gene. the APC gene maps in the long arm of chromosome 5 and was discovered in patients with familial adenomatous polyposis (FAP). The search for the APC gene led to the identification of restriction fragment length polymorphisms (RFLPs) in FAP patients. Using these RFLPs in relatives of FAP patients it is possible to make the presymptomatic and prenatal diagnosis. The FAP syndrome is an interesting model of carcinogenesis in vivo. Thus the different stages involved in the FAP syndrome which include hyperproliferative epithelium, adenoma, adenocarcinoma and metastases, have allowed the analysis of molecular alterations in oncogenes and tumor suppressor genes. The APC gene alteration if not inherited, occurs as the earliest molecular alteration in the development of colorectal cancer whereas structural alterations of the genes myc, ras, p53, MCC and DCC are considered to be late events. All these investigations have lead to 1) a better understanding of the ethiology of cancer and 2) early diagnosis of colorectal cancer in both the hereditary and sporadic forms of the disease.

  13. Synchronous trifocal colorectal cancer

    PubMed Central

    Charalampoudis, Petros; Kykalos, Stylianos; Stamopoulos, Paraskevas; Kouraklis, Gregory

    2016-01-01

    Synchronous colorectal cancers (SCRCs) have been increasingly diagnosed due to emerging diagnostic modalities. The presence of three or more synchronous colorectal cancers has, however, only rarely been reported. A 76-year-old white man presented for management of two concurrent colorectal adenocarcinomas in the left colon evidenced on total colonoscopy. Preoperative abdominal ultrasonography and thoracoabdominal computed tomography were negative for metastatic disease. The patient underwent an elective left hemicolectomy. The pathology report ultimately showed the presence of three moderately differentiated, distinct colorectal cancers. The patient experienced an uneventful recovery. PMID:27695171

  14. High FOXRED1 expression predicted good prognosis of colorectal cancer

    PubMed Central

    Fei, Weiqiang; Liu, Shuiping; Hu, Xiaotong

    2016-01-01

    The human FAD-dependent oxidoreductase domain containing 1 (FOXRED1) protein is reported as an assembly factor which promotes the correct assembly and stability of mitochondrial Complex I (CI). Alterations of mitochondrial CI might cause tumorigenesis and metastasis, but it’s molecular mechanisms remain unclear. In this study, we selected 145 cases of colorectal cancer for immunohistochemistry to explore the role of FOXRED1 played in the tumor progression of colorectal cancer. The relationship between FOXRED1 expression and clinicopathological features of colorectal cancers was evaluated. FOXRED1 mainly localized in the cytoplasm in the colorectal cancer tissues, and had significant association with histopathological grading, depth of invasion, lymph node metastasis, distant metastasis and TNM stage (P<0.05 for each). However, age, gender and tumor location was not found to be associated with FOXRED1 expression. Colorectal cancer patients with higher expression of FOXRED1 had the higher 3 year survival rate (P=0.003). Moreover, FOXRED1 had potentiality to be an independent prognostic factor for survival in colorectal cancer (P=0.04). Low FOXRED1 expression correlated with poor prognosis of colorectal cancer and targeting this molecular will be a potential treatment strategy for colorectal cancer. PMID:27904784

  15. Mineralization associated with scale and altered rock and pipe fragments from the Berlín geothermal field, El Salvador; implications for metal transport in natural systems

    NASA Astrophysics Data System (ADS)

    Raymond, Jasmin; Williams-Jones, Anthony E.; Clark, James R.

    2005-07-01

    Composite fragments sampled at solid collectors and drains of two-phase, re-injection, and vapour pipelines of the Berlín geothermal field, El Salvador, consist mainly of sulphide- and electrum-bearing aluminium-rich amorphous silica scale, sulphide- and electrum-bearing saponitic/vermiculitic clay from the reservoir, and altered metallic pipe linings containing As-S-bearing iron oxide-oxyhydroxide grains. Siliceous and clay-rich precipitates contain concentrations of gold and silver in excess of 180 and 8000 ppm, respectively, and appreciable concentrations of copper, lead, zinc, and antimony. Altered iron fragments contain substantial arsenic. Copper, lead, and zinc occur mainly as chalcopyrite, galena, and sphalerite, respectively, in amorphous silica and clay; near the surface, chalcopyrite transported from depth alters to bornite. Gold and silver occur mainly as electrum, which deposited with base metal sulphides in the clay precipitates, and amorphous silica at higher levels in the well. Electrum precipitates in the wells due to the rapid drop in temperature and loss of H 2S associated with boiling. The concentration of gold in vapour is ˜4 times greater than that in water from associated wellheads. This suggests that gold can be transported efficiently by vapour, and implies that such transport may be important in the formation of some hydrothermal ore deposits.

  16. Divergent mechanisms for the insulin resistant and hyperresponsive glucose transport in adipose cells from fasted and refed rats. Alterations in both glucose transporter number and intrinsic activity.

    PubMed Central

    Kahn, B B; Simpson, I A; Cushman, S W

    1988-01-01

    The effects of fasting and refeeding on the glucose transport response to insulin in isolated rat adipose cells have been examined using 3-O-methylglucose transport in intact cells and cytochalasin B binding and Western blotting in subcellular membrane fractions. After a 72-h fast, basal glucose transport activity decreases slightly and insulin-stimulated activity decreases greater than 85%. Following 48 h of fasting, insulin-stimulated glucose transport activity is diminished from 3.9 +/- 0.5 to 1.3 +/- 0.3 fmol/cell per min (mean +/- SEM). Similarly, the concentrations of glucose transporters are reduced with fasting in both the plasma membranes from insulin-stimulated cells from 38 +/- 5 to 18 +/- 3 pmol/mg of membrane protein and the low density microsomes from basal cells from 68 +/- 8 to 34 +/- 9 pmol/mg of membrane protein. Ad lib. refeeding for 6 d after a 48-h fast results in up to twofold greater maximally insulin-stimulated glucose transport activity compared with the control level (7.1 +/- 0.4 vs. 4.5 +/- 0.2 fmol/cell per min), before returning to baseline at 10 d. However, the corresponding concentration of glucose transporters in the plasma membranes is restored only to the control level (45 +/- 5 vs. 50 +/- 5 pmol/mg of membrane protein). Although the concentration of glucose transporters in the low density microsomes of basal cells remains decreased, the total number is restored to the control level due to an increase in low density microsomal protein. Thus, the insulin-resistant glucose transport in adipose cells from fasted rats can be explained by a decreased translocation of glucose transporters to the plasma membrane due to a depleted intracellular pool. In contrast, the insulin hyperresponsive glucose transport observed with refeeding appears to result from (a) a restored translocation of glucose transporters to the plasma membrane from a repleted intracellular pool and (b) enhanced plasma membrane glucose transporter intrinsic activity

  17. Clinical aspects of urea cycle dysfunction and altered brain energy metabolism on modulation of glutamate receptors and transporters in acute and chronic hyperammonemia.

    PubMed

    Natesan, Vijayakumar; Mani, Renuka; Arumugam, Ramakrishnan

    2016-07-01

    In living organisms, nitrogen arise primarily as ammonia (NH3) and ammonium (NH4(+)), which is a main component of the nucleic acid pool and proteins. Although nitrogen is essential for growth and maintenance in animals, but when the nitrogenous compounds exceeds the normal range which can quickly lead to toxicity and death. Urea cycle is the common pathway for the disposal of excess nitrogen through urea biosynthesis. Hyperammonemia is a consistent finding in many neurological disorders including congenital urea cycle disorders, reye's syndrome and acute liver failure leads to deleterious effects. Hyperammonemia and liver failure results in glutamatergic neurotransmission which contributes to the alteration in the function of the glutamate-nitric oxide-cGMP pathway, modulates the important cerebral process. Even though ammonia is essential for normal functioning of the central nervous system (CNS), in particular high concentrations of ammonia exposure to the brain leads to the alterations of glutamate transport by the transporters. Several glutamate transporters have been recognized in the central nervous system and each has a unique physiological property and distribution. The loss of glutamate transporter activity in brain during acute liver failure and hyperammonemia is allied with increased extracellular brain glutamate concentrations which may be conscientious for the cerebral edema and ultimately cell death. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  18. Schisandra chinensis peptidoglycan-assisted transmembrane transport of lignans uniquely altered the pharmacokinetic and pharmacodynamic mechanisms in human HepG2 cell model.

    PubMed

    Chyau, Charng-Cherng; Ker, Yaw-Bee; Chang, Chi-Huang; Huang, Shiau-Huei; Wang, Hui-Er; Peng, Chiung-Chi; Peng, Robert Y

    2014-01-01

    Schisandra chinensis (Turz Baill) (S. chinensis) (SC) fruit is a hepatoprotective herb containing many lignans and a large amount of polysaccharides. A novel polysaccharide (called SC-2) was isolated from SC of MW 841 kDa, which exhibited a protein-to-polysaccharide ratio of 0.4089, and showed a characteristic FTIR spectrum of a peptidoglycan. Powder X-ray diffraction revealed microcrystalline structures within SC-2. SC-2 contained 10 monosaccharides and 15 amino acids (essential amino acids of 78.12%w/w). In a HepG2 cell model, SC-2 was shown by MTT and TUNEL assay to be completely non-cytotoxic. A kinetic analysis and fluorescence-labeling technique revealed no intracellular disposition of SC-2. Combined treatment of lignans with SC-2 enhanced the intracellular transport of schisandrin B and deoxyschisandrin but decreased that of gomisin C, resulting in alteration of cell-killing bioactivity. The Second Law of Thermodynamics allows this type of unidirectional transport. Conclusively, SC-2 alters the transport and cell killing capability by a "Catcher-Pitcher Unidirectional Transport Mechanism".

  19. Schisandra chinensis Peptidoglycan-Assisted Transmembrane Transport of Lignans Uniquely Altered the Pharmacokinetic and Pharmacodynamic Mechanisms in Human HepG2 Cell Model

    PubMed Central

    Chyau, Charng-Cherng; Ker, Yaw-Bee; Chang, Chi-Huang; Huang, Shiau-Huei; Wang, Hui-Er; Peng, Chiung-Chi; Peng, Robert Y.

    2014-01-01

    Schisandra chinensis (Turz Baill) (S. chinensis) (SC) fruit is a hepatoprotective herb containing many lignans and a large amount of polysaccharides. A novel polysaccharide (called SC-2) was isolated from SC of MW 841 kDa, which exhibited a protein-to-polysaccharide ratio of 0.4089, and showed a characteristic FTIR spectrum of a peptidoglycan. Powder X-ray diffraction revealed microcrystalline structures within SC-2. SC-2 contained 10 monosaccharides and 15 amino acids (essential amino acids of 78.12%w/w). In a HepG2 cell model, SC-2 was shown by MTT and TUNEL assay to be completely non-cytotoxic. A kinetic analysis and fluorescence-labeling technique revealed no intracellular disposition of SC-2. Combined treatment of lignans with SC-2 enhanced the intracellular transport of schisandrin B and deoxyschisandrin but decreased that of gomisin C, resulting in alteration of cell-killing bioactivity. The Second Law of Thermodynamics allows this type of unidirectional transport. Conclusively, SC-2 alters the transport and cell killing capability by a “Catcher-Pitcher Unidirectional Transport Mechanism”. PMID:24475039

  20. Hsp70 and HSF-1 expression is altered in the tissues of pigs transported for various periods of times.

    PubMed

    Zhang, Miao; Yue, Zhenhua; Liu, Zhijun; Islam, Ali; Rehana, Buriro; Tang, Shu; Bao, Endong; Hartung, Jörg

    2012-09-01

    The aim of this study was to assess changes of Hsp70 and HSF-1 protein and mRNA expression in stress-sensitive organs of pigs during transportation for various periods of time. Twenty pigs were randomly divided into four groups (0 h, 1 h, 2 h, and 4 h of transportation). A significant increased activity of AST and CK was observed after 1 h and 2 h of transportation. Histopathological changes in the heart, liver, and stomach indicated that these organs sustained different degrees of injury. Hsp70 protein expression in the heart and liver of transported pigs did not change significantly while it increased significantly (p < 0.05) in the stomach. Hsp70 mRNA levels decreased significantly (p < 0.05) in the heart after 4 h of transportation. However, mRNA expression increased significantly in the liver after 1 (p < 0.05) and 4 h (p < 0.01) of transportation, and increased significantly in the stomach of the transported pigs after 1, 4 (p < 0.01), and 2 h (p < 0.05). HSF-1 levels were reduced at 1 and 4 h (p < 0.05) only in the hearts of transported pigs. These results indicate that Hsp70 mediates distinct stress-related functions in different tissues during transportation.

  1. Estradiol modulates Na(+) -dependent HCO3 (-) transporters altering intracellular pH and ion transport in human Sertoli cells: A role on male fertility?

    PubMed

    Bernardino, Raquel L; Costa, Ana R; Martins, Ana D; Silva, Joaquina; Barros, Alberto; Sousa, Mário; Sá, Rosália; Alves, Marco G; Oliveira, Pedro F

    2016-07-01

    Infertile men often present deregulation of serum estrogen levels. Notably, high levels of estradiol (E2) are associated with low sperm production and quality. Sertoli cells (SCs) are responsible for spermatogenesis maintenance and are major targets for the hormonal signalling that regulates this complex process. In this study, we used primary cultures of human SCs and studied the localisation, expression and functionality of the Na(+) -dependent HCO3 (-) transporters by confocal microscopy, immunoblot, epifluorescence and voltage clamp after 24 h of exposure to E2 (100 nM). All studied transporters were identified in human SCs. In E2-treated human SCs, there was an increase in NBCn1, NBCe1 and NDCBE protein levels, as well as an increase in intracellular pH and a decrease in transcellular transport. We report an association between increased levels of E2 and the expression/function of Na(+) -dependent HCO3 (-) transporters in human SCs. Our results provide new evidence on the mechanisms by which E2 can regulate SCs physiology and consequently spermatogenesis. These mechanisms may have an influence on male reproductive potential and help to explain male infertility conditions associated with estrogen deregulation. Exposure to E2 increased human SCs intracellular pH. E2 is a modulator of ionic transcellular transport in human SCs. © 2016 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  2. Altered tryptophan and alanine transport in fibroblasts from boys with attention-deficit/hyperactivity disorder (ADHD): an in vitro study.

    PubMed

    Johansson, Jessica; Landgren, Magnus; Fernell, Elisabeth; Vumma, Ravi; Åhlin, Arne; Bjerkenstedt, Lars; Venizelos, Nikolaos

    2011-09-24

    The catecholaminergic and serotonergic neurotransmitter systems are implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD). The amino acid tyrosine is the precursor for synthesis of the catecholamines dopamine and norepinephrine, while tryptophan is the precursor of serotonin. A disturbed transport of tyrosine, as well as other amino acids, has been found in a number of other psychiatric disorders, such as schizophrenia, bipolar disorder and autism, when using the fibroblast cell model. Hence, the aim of this study was to explore whether children with ADHD may have disturbed amino acid transport. Fibroblast cells were cultured from skin biopsies obtained from 14 boys diagnosed with ADHD and from 13 matching boys without a diagnosis of a developmental disorder. Transport of the amino acids tyrosine, tryptophan and alanine across the cell membrane was measured by the cluster tray method. The kinetic parameters, maximal transport capacity (V(max)) and affinity constant (K(m)) were determined. Any difference between the two groups was analyzed by Student's unpaired t-test or the Mann Whitney U test. The ADHD group had significantly decreased V(max) (p = 0.039) and K(m) (increased affinity) (p = 0.010) of tryptophan transport in comparison to controls. They also had a significantly higher V(max)of alanine transport (p = 0.031), but the Km of alanine transport did not differ significantly. There were no significant differences in any of the kinetic parameters regarding tyrosine transport in fibroblasts for the ADHD group. Tryptophan uses the same transport systems in both fibroblasts and at the blood brain barrier (BBB). Hence, a decreased transport capacity of tryptophan implies that less tryptophan is being transported across the BBB in the ADHD group. This could lead to deficient serotonin access in the brain that might cause disturbances in both the serotonergic and the catecholaminergic neurotransmitter systems, since these systems are

  3. A Novel Dominant Hyperekplexia Mutation Y705C Alters Trafficking and Biochemical Properties of the Presynaptic Glycine Transporter GlyT2*

    PubMed Central

    Giménez, Cecilio; Pérez-Siles, Gonzalo; Martínez-Villarreal, Jaime; Arribas-González, Esther; Jiménez, Esperanza; Núñez, Enrique; de Juan-Sanz, Jaime; Fernández-Sánchez, Enrique; García-Tardón, Noemí; Ibáñez, Ignacio; Romanelli, Valeria; Nevado, Julián; James, Victoria M.; Topf, Maya; Chung, Seo-Kyung; Thomas, Rhys H.; Desviat, Lourdes R.; Aragón, Carmen; Zafra, Francisco; Rees, Mark I.; Lapunzina, Pablo; Harvey, Robert J.; López-Corcuera, Beatriz

    2012-01-01

    Hyperekplexia or startle disease is characterized by an exaggerated startle response, evoked by tactile or auditory stimuli, producing hypertonia and apnea episodes. Although rare, this orphan disorder can have serious consequences, including sudden infant death. Dominant and recessive mutations in the human glycine receptor (GlyR) α1 gene (GLRA1) are the major cause of this disorder. However, recessive mutations in the presynaptic Na+/Cl−-dependent glycine transporter GlyT2 gene (SLC6A5) are rapidly emerging as a second major cause of startle disease. In this study, systematic DNA sequencing of SLC6A5 revealed a new dominant GlyT2 mutation: pY705C (c.2114A→G) in transmembrane domain 11, in eight individuals from Spain and the United Kingdom. Curiously, individuals harboring this mutation show significant variation in clinical presentation. In addition to classical hyperekplexia symptoms, some individuals had abnormal respiration, facial dysmorphism, delayed motor development, or intellectual disability. We functionally characterized this mutation using molecular modeling, electrophysiology, [3H]glycine transport, cell surface expression, and cysteine labeling assays. We found that the introduced cysteine interacts with the cysteine pair Cys-311–Cys-320 in the second external loop of GlyT2. This interaction impairs transporter maturation through the secretory pathway, reduces surface expression, and inhibits transport function. Additionally, Y705C presents altered H+ and Zn2+ dependence of glycine transport that may affect the function of glycinergic neurotransmission in vivo. PMID:22753417

  4. Prediction of Altered Bile Acid Disposition Due to Inhibition of Multiple Transporters: An Integrated Approach Using Sandwich-Cultured Hepatocytes, Mechanistic Modeling, and Simulation

    PubMed Central

    Guo, Cen; Yang, Kyunghee; Brouwer, Kenneth R.; St. Claire, Robert L.

    2016-01-01

    Transporter-mediated alterations in bile acid disposition may have significant toxicological implications. Current methods to predict interactions are limited by the interplay of multiple transporters, absence of protein in the experimental system, and inaccurate estimates of inhibitor concentrations. An integrated approach was developed to predict altered bile acid disposition due to inhibition of multiple transporters using the model bile acid taurocholate (TCA). TCA pharmacokinetic parameters were estimated by mechanistic modeling using sandwich-cultured human hepatocyte data with protein in the medium. Uptake, basolateral efflux, and biliary clearance estimates were 0.63, 0.034, and 0.074 mL/min/g liver, respectively. Cellular total TCA concentrations (Ct,Cells) were selected as the model output based on sensitivity analysis. Monte Carlo simulations of TCA Ct,Cells in the presence of model inhibitors (telmisartan and bosentan) were performed using inhibition constants for TCA transporters and inhibitor concentrations, including cellular total inhibitor concentrations ([I]t,cell) or unbound concentrations, and cytosolic total or unbound concentrations. For telmisartan, the model prediction was accurate with an average fold error (AFE) of 0.99–1.0 when unbound inhibitor concentration ([I]u) was used; accuracy dropped when total inhibitor concentration ([I]t) was used. For bosentan, AFE was 1.2–1.3 using either [I]u or [I]t. This difference was evaluated by sensitivity analysis of the cellular unbound fraction of inhibitor (fu,cell,inhibitor), which revealed higher sensitivity of fu,cell,inhibitor for predicting TCA Ct,Cells when inhibitors exhibited larger ([I]t,cell/IC50) values. In conclusion, this study demonstrated the applicability of a framework to predict hepatocellular bile acid concentrations due to drug-mediated inhibition of transporters using mechanistic modeling and cytosolic or cellular unbound concentrations. PMID:27233294

  5. Alteration of flavonoid accumulation patterns in transparent testa mutants disturbs auxin transport, gravity responses, and imparts long-term effects on root and shoot architecture.

    PubMed

    Buer, Charles S; Kordbacheh, Farzanah; Truong, Thy T; Hocart, Charles H; Djordjevic, Michael A

    2013-07-01

    Flavonoids have broad cross-kingdom biological activity. In Arabidopsis, flavonoid accumulation in specific tissues, notably the root elongation zone and root/shoot junction modulate auxin transport, affect root gravitropism, and influence overall plant architecture. The relative contribution made by aglycones and their glycosides remains undetermined, and the longer-term phenotypic effects of altered flavonoid accumulation are not fully assessed. We tested Arabidopsis thaliana mutants that accumulate different flavonoids to determine which flavonoids were causing these affects. Tandem mass spectrometry and in situ fluorescence localisation were used to determine the in vivo levels of aglycones in specific tissues of 11 transparent testa mutants. We measured rootward and shootward auxin transport, gravitropic responses, and identified the long-term changes to root and shoot architecture. Unexpected aglycone species accumulated in vivo in several flavonoid-pathway mutants, and lower aglycone levels occurred in transcription factor mutants. Mutants accumulating more quercetin and quercetin-glycosides changed the greatest in auxin transport, gravitropism, and aerial tissue growth. Early flavonoid-pathway mutants showed aberrant lateral root initiation patterns including clustered lateral root initiations at a single site. Transcription factor mutants had multiple phenotypes including shallow root systems. These results confirm that aglycones are present at very low levels, show that lateral root initiation is perturbed in early flavonoid-pathway mutants, and indicate that altered flavonoid accumulation affects multiple aspects of plant architecture.

  6. Amelioration of hypoxia-induced striatal 5-HT(2A) receptor, 5-HT transporter and HIF1 alterations by glucose, oxygen and epinephrine in neonatal rats.

    PubMed

    Anju, T R; Paulose, C S

    2011-09-20

    Alterations in neurotransmitters and its receptors expression induce brain injury during neonatal hypoxic insult. Molecular processes regulating the serotonergic receptors play an important role in the control of respiration under hypoxic insult. The present study focused on the serotonergic regulation of neonatal hypoxia and its resuscitation methods. Receptor binding assays and gene expression studies were done to evaluate the changes in 5HT(2A) receptors and its transporter in the corpus striatum of hypoxic neonatal rats and hypoxic rats resuscitated with glucose, oxygen and epinephrine. Total 5HT and 5HT(2A) receptor number was increased in hypoxic neonates along with an up regulation of 5HT(2A) receptor and 5HT transporter gene. The enhanced striatal 5HT(2A) receptors modulate the ventilatory response to hypoxia. Immediate glucose resuscitation was found to ameliorate the receptor and transporter alterations. Hypoxia induced ATP depletion mediated reduction in blood glucose levels can be encountered by glucose administration and oxygenation helps in overcoming the anaerobic condition. The adverse effect of immediate oxygenation and epinephrine supplementation was also reported. This has immense clinical significance in establishing a proper resuscitation for the management of neonatal hypoxia.

  7. Shoot Na+ Exclusion and Increased Salinity Tolerance Engineered by Cell Type–Specific Alteration of Na+ Transport in Arabidopsis[W][OA

    PubMed Central

    Møller, Inge S.; Gilliham, Matthew; Jha, Deepa; Mayo, Gwenda M.; Roy, Stuart J.; Coates, Juliet C.; Haseloff, Jim; Tester, Mark

    2009-01-01

    Soil salinity affects large areas of cultivated land, causing significant reductions in crop yield globally. The Na+ toxicity of many crop plants is correlated with overaccumulation of Na+ in the shoot. We have previously suggested that the engineering of Na+ exclusion from the shoot could be achieved through an alteration of plasma membrane Na+ transport processes in the root, if these alterations were cell type specific. Here, it is shown that expression of the Na+ transporter HKT1;1 in the mature root stele of Arabidopsis thaliana decreases Na+ accumulation in the shoot by 37 to 64%. The expression of HKT1;1 specifically in the mature root stele is achieved using an enhancer trap expression system for specific and strong overexpression. The effect in the shoot is caused by the increased influx, mediated by HKT1;1, of Na+ into stelar root cells, which is demonstrated in planta and leads to a reduction of root-to-shoot transfer of Na+. Plants with reduced shoot Na+ also have increased salinity tolerance. By contrast, plants constitutively expressing HKT1;1 driven by the cauliflower mosaic virus 35S promoter accumulated high shoot Na+ and grew poorly. Our results demonstrate that the modification of a specific Na+ transport process in specific cell types can reduce shoot Na+ accumulation, an important component of salinity tolerance of many higher plants. PMID:19584143

  8. Extracellular Cl− regulates human SO42−/anion exchanger SLC26A1 by altering pH-sensitivity of anion transport

    PubMed Central

    Wu, Meng; Heneghan, John F.; Vandorpe, David H.; Escobar, Laura I.; Wu, Bai-Lin; Alper, Seth L.

    2016-01-01

    Genetic deficiency of the SLC26A1 anion exchanger in mice is known to be associated with hyposulfatemia and hyperoxaluria with nephrolithiasis, but many aspects of human SLC26A1 function remain to be explored. We report here the functional characterization of human SLC26A1, a DIDS-sensitive, electroneutral sodium-independent anion exchanger transporting sulfate, oxalate, bicarbonate, thiosulfate and (with divergent properties) chloride. Human SLC26A1-mediated anion exchange differs from that of its rodent orthologs in its stimulation by alkaline pHo and inhibition by acidic pHo but not pHi, and in its failure to transport glyoxylate. SLC26A1-mediated transport of sulfate and oxalate is highly dependent on allosteric activation by extracellular chloride or nonsubstrate anions. Extracellular chloride stimulates apparent Vmax of human SLC26A1-mediated sulfate uptake by conferring a two-log decrease in sensitivity to inhibition by extracellular protons, without changing transporter affinity for extracellular sulfate. In contrast to SLC26A1-mediated sulfate transport, SLC26A1-associated chloride transport is activated by acid pHo, shows reduced sensitivity to DIDS, and exhibits cation-dependence of its DIDS-insensitive component. Human SLC26A1 resembles SLC26 paralogs in its inhibition by phorbol ester activation of PKC, which differs in its undiminished polypeptide abundance at or near the oocyte surface. Mutation of SLC26A1 residues corresponding to candidate anion binding site-associated residues in avian SLC26A5/prestin altered anion transport in patterns resembling those of prestin. However, rare SLC26A1 polymorphic variants from a patient with renal Fanconi Syndrome and from a patient with nephrolithiasis/calcinosis exhibited no loss-of-function phenotypes consistent with disease pathogenesis. PMID:27125215

  9. [Chemoprevention of colorectal cancer].

    PubMed

    Herszényi, László; Juhász, Márk; Prónai, László; Tulassay, Zsolt

    2004-03-21

    Although colorectal cancer is one of the most preventable forms of cancer, it remains the second leading cause of cancer death worldwide. Primary prevention involves the identification and elimination of factors, which cause or promote colorectal cancer. The goal of screening is to prevent colorectal cancer mortality through the detection and treatment of premalignant adenomas and curable-stage cancer. Most colorectal cancers are believed to arise from adenomatous polyps. Early identification and removal of adenomas can prevent the development of colorectal cancer. Chemoprevention is the use of specific chemical compounds to prevent, inhibit, or reverse carcinogenesis. Several chemoprevention options have been investigated and confirmed as effective. Aspirin and other nonsteroidal anti-inflammatory drugs are the most widely studied agents, their use has been consistently associated with reduction in the risk of mortality and the incidence of colorectal adenomas and cancers. The selective cyclooxygenase-2 (COX-2) inhibitors (coxibs) have been demonstrated to decrease the number and the size of polyps in patients with familial adenomatous polyposis syndrome. Because the gastrointestinal toxicity of coxibs is lower, it might be safer than aspirin or other non-selective nonsteroidal anti-inflammatory drugs for long-term use. This review aims to summarize the recent theoretical and practical advances in the chemoprevention of colorectal cancer.

  10. Robotic colorectal surgery.

    PubMed

    Baik, Seung Hyuk

    2008-12-31

    Robotic colorectal surgery has gradually been performed more with the help of the technological advantages of the da Vinci system. Advanced technological advantages of the da Vinci system compared with standard laparoscopic colorectal surgery have been reported. These are a stable camera platform, three-dimensional imaging, excellent ergonomics, tremor elimination, ambidextrous capability, motion scaling, and instruments with multiple degrees of freedom. However, despite these technological advantages, most studies did not report the clinical advantages of robotic colorectal surgery compared to standard laparoscopic colorectal surgery. Only one study recently implies the real benefits of robotic rectal cancer surgery. The purpose of this review article is to outline the early concerns of robotic colorectal surgery using the da Vinci system, to present early clinical outcomes from the most current series, and to discuss not only the safety and the feasibility but also the real benefits of robotic colorectal surgery. Moreover, this article will comment on the possible future clinical advantages and limitations of the da Vinci system in robotic colorectal surgery.

  11. Expression of apical junction complex proteins in colorectal mucosa of miniature dachshunds with inflammatory colorectal polyps

    PubMed Central

    YOKOYAMA, Nozomu; OHTA, Hiroshi; KAGAWA, Yumiko; LEELA-ARPORN, Rommaneeya; DERMLIM, Angkhana; NISA, Khoirun; MORITA, Tomoya; OSUGA, Tatsuyuki; SASAKI, Noboru; MORISHITA, Keitaro; NAKAMURA, Kensuke; TAKIGUCHI, Mitsuyoshi

    2017-01-01

    We examine the expression of tight junction and adherence junction proteins in the colorectal mucosa of miniature dachshunds (MDs) with inflammatory colorectal polyps (ICRPs). Colorectal mucosa samples were endoscopically obtained from 8 MDs with ICRPs and 8 control dogs for immunoblotting. Paraffin-embedded tissues of surgically resected inflamed lesions from another 5 MDs with ICRPs and full-thickness colorectal specimens from 5 healthy beagles were obtained for immunohistochemistry. The expression patterns of claudin-1, -2, -3, -4, -5, -7 and -8, E-cadherin and β-catenin were analyzed in the non-inflamed mucosa and inflamed mucosa of ICRPs and colorectal mucosa of control dogs by immunoblotting. The localization of these proteins in the inflamed lesions was analyzed by immunohistochemistry. The expressions of each of claudin, E-cadherin and β-catenin were not significantly different between control dogs and non-inflamed colonic mucosa from MDs with ICRPs. In contrast, only E-cadherin and β-catenin were detected in the inflamed lesions of MDs with ICRPs. By immunohistochemistry, claudin-2, -3, -4, -5 and -7, E-cadherin and β-catenin were expressed in the colorectal epithelium within the inflamed mucosa, but not in granulation tissue. Distributions of claudin-2, -3, -4, -5, and -7, E-cadherin and β-catenin in the colonic epithelium were not different between MDs with ICRPs and control dogs. These results indicated that no significant alteration was detected in several tight junction or adherence junction proteins expression in the colorectal epithelium of ICRPs. PMID:28090006

  12. Fusobacterium nucleatum Promotes Chemoresistance to Colorectal Cancer by Modulating Autophagy.

    PubMed

    Yu, TaChung; Guo, Fangfang; Yu, Yanan; Sun, Tiantian; Ma, Dan; Han, Jixuan; Qian, Yun; Kryczek, Ilona; Sun, Danfeng; Nagarsheth, Nisha; Chen, Yingxuan; Chen, Haoyan; Hong, Jie; Zou, Weiping; Fang, Jing-Yuan

    2017-07-27

    Gut microbiota are linked to chronic inflammation and carcinogenesis. Chemotherapy failure is the major cause of recurrence and poor prognosis in colorectal cancer patients. Here, we investigated the contribution of gut microbiota to chemoresistance in patients with colorectal cancer. We found that Fusobacterium (F.) nucleatum was abundant in colorectal cancer tissues in patients with recurrence post chemotherapy, and was associated with patient clinicopathological characterisitcs. Furthermore, our bioinformatic and functional studies demonstrated that F. nucleatum promoted colorectal cancer resistance to chemotherapy. Mechanistically, F. nucleatum targeted TLR4 and MYD88 innate immune signaling and specific microRNAs to activate the autophagy pathway and alter colorectal cancer chemotherapeutic response. Thus, F. nucleatum orchestrates a molecular network of the Toll-like receptor, microRNAs, and autophagy to clinically, biologically, and mechanistically control colorectal cancer chemoresistance. Measuring and targeting F. nucleatum and its associated pathway will yield valuable insight into clinical management and may ameliorate colorectal cancer patient outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Acute changes in cellular zinc alters zinc uptake rates prior to zinc transporter gene expression in Jurkat cells.

    PubMed

    Holland, Tai C; Killilea, David W; Shenvi, Swapna V; King, Janet C

    2015-12-01

    A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells.

  14. Perinatal Na+ overload programs raised renal proximal Na+ transport and enalapril-sensitive alterations of Ang II signaling pathways during adulthood.

    PubMed

    Cabral, Edjair V; Vieira-Filho, Leucio D; Silva, Paulo A; Nascimento, Williams S; Aires, Regina S; Oliveira, Fabiana S T; Luzardo, Ricardo; Vieyra, Adalberto; Paixão, Ana D O

    2012-01-01

    High Na(+) intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na(+) overload-programmed alterations in Na(+) transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na(+)+K(+))ATPase expression and activity. Ouabain-insensitive Na(+)-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT(2) receptor expression decreased while AT(1) expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na(+)+K(+))ATPase, partially recovered the response of Na(+)-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na(+) or not. In addition, treatment with enalapril per se reduced AT(2) receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na(+)-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. Maternal Na(+) overload programmed alterations in renal Na(+) transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril was beneficial predominantly through

  15. Polymorphic CAG Repeat and Protein Expression of Androgen Receptor Gene in Colorectal Cancer.

    PubMed

    Huang, Rui; Wang, Guiyu; Song, Yanni; Wang, Feng; Zhu, Bing; Tang, Qingchao; Liu, Zheng; Chen, Yinggang; Zhang, Qian; Muhammad, Shan; Wang, Xishan

    2015-04-01

    Although somatic alterations in CAG repeats in the androgen receptor (AR) gene have been suggested to predispose to colorectal cancer, less is known about AR in colorectal cancer carcinogenesis. Because of lack of relevant analysis on CAG repeat length and AR expression in colorectal cancer, we aimed to investigate the prognostic value of polymorphic CAG and protein expression of the AR gene in patients with colorectal cancer. A case-control study was carried out on 550 patients with colorectal cancer and 540 healthy controls to investigate whether polymorphic CAG within the AR gene is linked to increased risk for colorectal cancer. Polymorphic CAG and AR expression were analyzed to clarify their relationship with clinicopathologic and prognostic factors in patients with colorectal cancer. The study showed that the AR gene in patients with colorectal cancer had a longer CAG repeat sequence than those in the control group, as well as increased risk for colorectal cancer among females (P = 0.013), males (P = 0.002), and total colorectal cancer population (P < 0.001), respectively. AR expression exhibited a significant difference in long CAG repeat sequence among males (P < 0.001), females (P < 0.001), and total colorectal cancer study population (P < 0.001). Both long CAG repeat sequence and negative AR expression were associated with a short 5-year overall survival (OS) rate in colorectal cancer. Long CAG repeat sequences and the absence of AR expression were closely related to the development of colorectal cancer. Both long CAG and decreased AR expression were correlated with the poor 5-year OS in patients with colorectal cancer.

  16. Colorectal cancer screening.

    PubMed

    Chan, Pak Wo Webber; Ngu, Jing Hieng; Poh, Zhongxian; Soetikno, Roy

    2017-01-01

    Colorectal cancer, which is the leading cancer in Singapore, can be prevented by increased use of screening and polypectomy. A range of screening strategies such as stool-based tests, flexible sigmoidoscopy, colonoscopy and computed tomography colonography are available, each with different strengths and limitations. Primary care physicians should discuss appropriate screening modalities with their patients, tailored to their individual needs. Physicians, patients and the government should work in partnership to improve uptake of colorectal cancer screening to reduce the morbidity and mortality from colorectal cancer. Copyright: © Singapore Medical Association.

  17. Colorectal cancer screening

    PubMed Central

    Chan, Pak Wo Webber; Ngu, Jing Hieng; Poh, Zhongxian; Soetikno, Roy

    2017-01-01

    Colorectal cancer, which is the leading cancer in Singapore, can be prevented by increased use of screening and polypectomy. A range of screening strategies such as stool-based tests, flexible sigmoidoscopy, colonoscopy and computed tomography colonography are available, each with different strengths and limitations. Primary care physicians should discuss appropriate screening modalities with their patients, tailored to their individual needs. Physicians, patients and the government should work in partnership to improve uptake of colorectal cancer screening to reduce the morbidity and mortality from colorectal cancer. PMID:28111691

  18. Abnormal N-Glycosylation of a Novel Missense Creatine Transporter Mutant, G561R, Associated with Cerebral Creatine Deficiency Syndromes Alters Transporter Activity and Localization.

    PubMed

    Uemura, Tatsuki; Ito, Shingo; Ohta, Yusuke; Tachikawa, Masanori; Wada, Takahito; Terasaki, Tetsuya; Ohtsuki, Sumio

    2017-01-01

    Cerebral creatine deficiency syndromes (CCDSs) are caused by loss-of-function mutations in creatine transporter (CRT, SLC6A8), which transports creatine at the blood-brain barrier and into neurons of the central nervous system (CNS). This results in low cerebral creatine levels, and patients exhibit mental retardation, poor language skills and epilepsy. We identified a novel human CRT gene missense mutation (c.1681 G>C, G561R) in Japanese CCDSs patients. The purpose of the present study was to evaluate the reduction of creatine transport in G561R-mutant CRT-expressing 293 cells, and to clarify the mechanism of its functional attenuation. G561R-mutant CRT exhibited greatly reduced creatine transport activity compared to wild-type CRT (WT-CRT) when expressed in 293 cells. Also, the mutant protein is localized mainly in intracellular membrane fraction, while WT-CRT is localized in plasma membrane. Western blot analysis revealed a 68 kDa band of WT-CRT protein in plasma membrane fraction, while G561R-mutant CRT protein predominantly showed bands at 55, 110 and 165 kDa in crude membrane fraction. The bands of both WT-CRT and G561R-mutant CRT were shifted to 50 kDa by N-glycosidase treatment. Our results suggest that the functional impairment of G561R-mutant CRT was probably caused by incomplete N-linked glycosylation due to misfolding during protein maturation, leading to oligomer formation and changes of cellular localization.

  19. Interferon-γ alters downstream signaling originating from epidermal growth factor receptor in intestinal epithelial cells: functional consequences for ion transport.

    PubMed

    Paul, Gisela; Marchelletta, Ronald R; McCole, Declan F; Barrett, Kim E

    2012-01-13

    The epidermal growth factor receptor (EGFr) regulates many cellular functions, such as proliferation, apoptosis, and ion transport. Our aim was to investigate whether long term treatment with interferon-γ (IFN-γ) modulates EGF activation of downstream signaling pathways in intestinal epithelial cells and if this contributes to dysregulation of epithelial ion transport in inflammation. Polarized monolayers of T(84) and HT29/cl.19A colonocytes were preincubated with IFN-γ prior to stimulation with EGF. Basolateral potassium transport was studied in Ussing chambers. We also studied inflamed colonic mucosae from C57BL/6 mice treated with dextran sulfate sodium or mdr1a knock-out mice and controls. IFN-γ increased intestinal epithelial EGFr expression without increasing its phosphorylation. Conversely, IFN-γ caused a significant decrease in EGF-stimulated phosphorylation of specific EGFr tyrosine residues and activation of ERK but not Akt-1. In IFNγ-pretreated cells, the inhibitory effect of EGF on carbachol-stimulated K(+) channel activity was lost. In inflamed colonic tissues, EGFr expression was significantly increased, whereas ERK phosphorylation was reduced. Thus, although it up-regulates EGFr expression, IFN-γ causes defective EGFr activation in colonic epithelial cells via reduced phosphorylation of specific EGFr tyrosine residues. This probably accounts for altered downstream signaling consequences. These observations were corroborated in the setting of colitis. IFN-γ also abrogates the ability of EGF to inhibit carbachol-stimulated basolateral K(+) currents. Our data suggest that, in the setting of inflammation, the biological effect of EGF, including the inhibitory effect of EGF on Ca(2+)-dependent ion transport, is altered, perhaps contributing to diarrheal and other symptoms in vivo.

  20. Altered GABAA receptor density and unaltered blood-brain barrier transport in a kainate model of epilepsy: an in vivo study using 11C-flumazenil and PET.

    PubMed

    Syvänen, Stina; Labots, Maaike; Tagawa, Yoshihiko; Eriksson, Jonas; Windhorst, Albert D; Lammertsma, Adriaan A; de Lange, Elizabeth C; Voskuyl, Rob A

    2012-12-01

    The aim of the present study was to investigate if flumazenil blood-brain barrier transport and binding to the benzodiazepine site on the γ-aminobutyric acid A (GABA(A)) receptor complex is altered in an experimental model of epilepsy and subsequently to study if changes in P-glycoprotein (P-gp)-mediated efflux of flumazenil at the blood-brain barrier may confound interpretation of (11)C-flumazenil PET in epilepsy. The transport of flumazenil across the blood-brain barrier and the binding to the benzodiazepine site on the GABA(A) receptors in 5 different brain regions was studied and compared between controls and kainate-treated rats, a model of temporal lobe epilepsy, with and without tariquidar pretreatment. In total, 29 rats underwent 2 consecutive (11)C-flumazenil PET scans, each one lasting 30 min. The tracer was mixed with different amounts of isotopically unmodified flumazenil (4, 20, 100, or 400 μg) to cover a wide range of receptor occupancies during the scan. Before the second scan, the rats were pretreated with a 3 or 15 mg/kg dose of the P-gp inhibitor tariquidar. The second scan was then obtained according to the same protocol as the first scan. GABA(A) receptor density, B(max), was estimated as 44 ± 2 ng x mL(-1) in the hippocampus and as 33 ± 2 ng x mL(-1) in the cerebellum, with intermediate values in the occipital cortex, parietal cortex, and caudate putamen. B(max) was decreased by 12% in kainate-treated rats, compared with controls. The radiotracer equilibrium dissociation constant, K(D), was similar in both rat groups and all brain regions and was estimated as 5.9 ± 0.9 ng x mL(-1). There was no difference in flumazenil transport across the blood-brain barrier between control and kainate-treated rats, and the effect of tariquidar treatment was similar in both rat groups. Tariquidar treatment also decreased flumazenil transport out of the brain by 73%, increased the volume of distribution in the brain by 24%, and did not influence B(max) or

  1. Altered growth and improved resistance of Arabidopsis against Pseudomonas syringae by overexpression of the basic amino acid transporter AtCAT1.

    PubMed

    Yang, Huaiyu; Postel, Sandra; Kemmerling, Birgit; Ludewig, Uwe

    2014-06-01

    Amino acid transporters in plants are crucial for distributing amino acids between plant organs and cellular compartments. The H(+)-coupled plasma membrane transporter CAT1 (cationic amino acid transporter 1) facilitates the high-affinity uptake of basic amino acids. The uptake of lysine (Lys) via the roots was not altered in loss-of-function mutants, in accordance with the minor expression of CAT1 in roots, but plants ectopically overexpressing CAT1 incorporated Lys at higher rates. Exogenous Lys inhibited the primary root of Arabidopsis, whereas lateral roots were stimulated. These effects were augmented by the presence or absence of CAT1. Furthermore, the total biomass of soil-grown plants ectopically overexpressing CAT1 was reduced and the time to flowering was accelerated. These effects were accompanied by only minor changes in the overall amino acid profile. Interestingly, CAT1 belongs to a specific small cluster of nitrogen-containing metabolite transporter genes that are rapidly up-regulated upon infection with Pseudomonas syringae and that may participate in the systemic response of plants to pathogen attack. The overexpression of CAT1 indeed enhanced the resistance to the hemibiotrophic bacterial pathogen P. syringae via a constitutively activated salicylic acid (SA) pathway, which is consistent with the developmental defects and the resistance phenotype.

  2. Transportation

    NASA Technical Reports Server (NTRS)

    Vontiesenhausen, G.

    1986-01-01

    A summary of tether transportation is given. Four steps were used over a period of time. First, theoretical engineering feasibility and technology requirements were determined. Then the survivors of that effort went into step two in the analysis of promising candidates. Those survivors went into the third phase which is engineering design and cost benefits. Survivors entered into the demonstration mission definition phase. Transportation studies have covered two kinds of deployments. First, steady state deployment was studied. Like the TSS, it's nearly vertical. It takes a long time to deploy and involves relatively high tether tension. Secondly, dynamic deployment was studied. Deployment started in an almost horizontal direction under a very shallow angle which allows a high deployment rate under very low tension. Momentum transfer here occurs by libration. Specific payloads were used to study tethered transportation benefits. Four transportation concepts were studied with regard to cost benefits. A tethered orbiter deboost from the space station, an OTV boost up from the Space Station, a science platform on a tether with a possible micro-g lab moving in between platform and station, and a tethered boost of payloads fromthe orbiter are the four concepts. These benefits are examined in detail.

  3. Altered expression of polyamine transporters reveals a role for spermidine in the timing of flowering and other developmental response pathways.

    PubMed

    Ahmed, Sheaza; Ariyaratne, Menaka; Patel, Jigar; Howard, Alexander E; Kalinoski, Andrea; Phuntumart, Vipaporn; Morris, Paul F

    2017-05-01

    Changes in the levels of polyamines are correlated with the activation or repression of developmental response pathways, but the role of polyamine transporters in the regulation of polyamine homeostasis and thus indirectly gene expression, has not been previously addressed. Here we show that the A. thaliana and rice transporters AtPUT5 and OsPUT1 were localized to the ER, while the AtPUT2, AtPUT3, and OsPUT3 were localized to the chloroplast by transient expression in N. benthamiana. A. thaliana plants that were transformed with OsPUT1 under the control the PUT5 promoter were delayed in flowering by 16days. In contrast, put5 mutants flowered four days earlier than WT plants. The delay of flowering was associated with significantly higher levels of spermidine and spermidine conjugates in the leaves prior to flowering. A similar delay in flowering was also noted in transgenic lines with constitutive expression of either OsPUT1 or OsPUT3. All three transgenic lines had larger rosette leaves, thicker flowering stems, and produced more siliques than wild type plants. In contrast, put5 plants had smaller leaves, thinner flowering stems, and produced fewer siliques. Constitutive expression of PUTs was also associated with an extreme delay in both plant senescence and maturation rate of siliques. These experiments provide the first genetic evidence of polyamine transport in the timing of flowering, and indicate the importance of polyamine transporters in the regulation of flowering and senescence pathways.

  4. Knockdown of a Rice Stelar Nitrate Transporter Alters Long-Distance Translocation But Not Root Influx1[W][OA

    PubMed Central

    Tang, Zhong; Fan, Xiaorong; Li, Qing; Feng, Huimin; Miller, Anthony J.; Shen, Qirong; Xu, Guohua

    2012-01-01

    Root nitrate uptake is well known to adjust to the plant’s nitrogen demand for growth. Long-distance transport and/or root storage pools are thought to provide negative feedback signals regulating root uptake. We have characterized a vascular specific nitrate transporter belonging to the high-affinity Nitrate Transporter2 (NRT2) family, OsNRT2.3a, in rice (Oryza sativa ssp. japonica ‘Nipponbare’). Localization analyses using protoplast expression, in planta promoter-β-glucuronidase assay, and in situ hybridization showed that OsNRT2.3a was located in the plasma membrane and mainly expressed in xylem parenchyma cells of the stele of nitrate-supplied roots. Knockdown expression of OsNRT2.3a by RNA interference (RNAi) had impaired xylem loading of nitrate and decreased plant growth at low (0.5 mm) nitrate supply. In comparison with the wild type, the RNAi lines contained both nitrate and total nitrogen significantly higher in the roots and lower in the shoots. The short-term [15N]NO3− influx (5 min) in entire roots and NO3− fluxes in root surfaces showed that the knockdown of OsNRT2.3a in comparison with the wild type did not affect nitrate uptake by roots. The RNAi plants showed no significant changes in the expression of some root nitrate transporters (OsNRT2.3b, OsNRT2.4, and OsNAR2.1), but transcripts for nia1 (nitrate reductase) had increased and OsNRT2.1 and OsNRT2.2 had decreased when the plants were supplied with nitrate. Taken together, the data demonstrate that OsNRT2.3a plays a key role in long-distance nitrate transport from root to shoot at low nitrate supply level in rice. PMID:23093362

  5. Colorectal Cancer Prevention

    MedlinePlus

    ... linked to a decreased risk of colorectal cancer. Aspirin Studies have shown that taking aspirin lowers the ... cancer: Nonsteroidal anti-inflammatory drugs (NSAIDs) other than aspirin It is not known if the use of ...

  6. Epidemiology of colorectal cancer

    PubMed Central

    Marley, Andrew R; Nan, Hongmei

    2016-01-01

    Colorectal cancer is currently the third deadliest cancer in the United States and will claim an estimated 49,190 U.S. lives in 2016. The purpose of this review is to summarize our current understanding of this disease, based on nationally published statistics and information presented in peer-reviewed journal articles. Specifically, this review will cover the following topics: descriptive epidemiology (including time and disease trends both in the United States and abroad), risk factors (environmental, genetic, and gene-environment interactions), screening, prevention and control, and treatment. Landmark discoveries in colorectal cancer risk factor research will also be presented. Based on the information reviewed for this report, we suggest that future U.S. public health efforts aim to increase colorectal cancer screening among African American communities, and that future worldwide colorectal cancer epidemiology studies should focus on researching nutrient-gene interactions towards the goal of improving personalized treatment and prevention strategies. PMID:27766137

  7. Colorectal Cancer Coalition

    MedlinePlus

    ... inspire those touched by colorectal cancer. Watch Videos Join us on the hill Attend our annual advocacy ... We always need volunteers. Browse our opportunities. Volunteer Join the Movement We have many ways to fight ...

  8. Colorectal carcinoma: Pathologic aspects

    PubMed Central

    Fleming, Matthew; Ravula, Sreelakshmi; Tatishchev, Sergei F.

    2012-01-01

    Colorectal carcinoma is one of the most common cancers and one of the leading causes of cancer-related death in the United States. Pathologic examination of biopsy, polypectomy and resection specimens is crucial to appropriate patient managemnt, prognosis assessment and family counseling. Molecular testing plays an increasingly important role in the era of personalized medicine. This review article focuses on the histopathology and molecular pathology of colorectal carcinoma and its precursor lesions, with an emphasis on their clinical relevance. PMID:22943008

  9. Oral peptide specific egg antibody to intestinal sodium-dependent phosphate co-transporter-2b is effective at altering phosphate transport in vitro and in vivo.

    PubMed

    Bobeck, Elizabeth A; Hellestad, Erica M; Sand, Jordan M; Piccione, Michelle L; Bishop, Jeff W; Helvig, Christian; Petkovich, Martin; Cook, Mark E

    2015-06-01

    Hyperimmunized hens are an effective means of generating large quantities of antigen specific egg antibodies that have use as oral supplements. In this study, we attempted to create a peptide specific antibody that produced outcomes similar to those of the human pharmaceutical, sevelamer HCl, used in the treatment of hyperphosphatemia (a sequela of chronic renal disease). Egg antibodies were generated against 8 different human intestinal sodium-dependent phosphate cotransporter 2b (NaPi2b) peptides, and hNaPi2b peptide egg antibodies were screened for their ability to inhibit phosphate transport in human intestinal Caco-2 cell line. Antibody produced against human peptide sequence TSPSLCWT (anti-h16) was specific for its peptide sequence, and significantly reduced phosphate transport in human Caco-2 cells to 25.3±11.5% of control nonspecific antibody, when compared to nicotinamide, a known inhibitor of phosphate transport (P≤0.05). Antibody was then produced against the mouse-specific peptide h16 counterpart (mouse sequence TSPSYCWT, anti-m16) for further analysis in a murine model. When anti-m16 was fed to mice (1% of diet as dried egg yolk powder), egg yolk immunoglobulin (IgY) was detected using immunohistochemical staining in mouse ileum, and egg anti-m16 IgY colocalized with a commercial goat anti-NaPi2b antibody. The effectiveness of anti-m16 egg antibody in reducing serum phosphate, when compared to sevelamer HCl, was determined in a mouse feeding study. Serum phosphate was reduced 18% (P<0.02) in mice fed anti-m16 (1% as dried egg yolk powder) and 30% (P<0.0001) in mice fed sevelamer HCl (1% of diet) when compared to mice fed nonspecific egg immunoglobulin. The methods described and the findings reported show that oral egg antibodies are useful and easy to prepare reagents for the study and possible treatment of select diseases.

  10. [Epidemiology of colorectal cancer].

    PubMed

    Bouvier, Anne-Marie; Launoy, Guy

    2015-06-01

    The incidence of colorectal cancer increased in France until the 2000s' then decreased. Time trends in incidence for this cancer varied according to its sublocation along the gut. Incidence increased for right and left colon cancers, whereas it remained stable for sigmoid cancers in males and decreased in females. Incidence decreased over time for rectal cancers. The proportion of colorectal cancer in the overall French cancer prevalence is 12%. In 2008, 121,000 patients had a colorectal cancer diagnosed in the 5 previous years. The cumulative risk of colorectal cancer increased from 3.9% for males born around 1900 to 4.9% for those born around 1930 and then slightly decreased, being 4.5% among those born around 1950. It remained at the same level for females and was 2.9% for those born around 1950. The prognosis of colorectal cancer improved over time. Net 5-year survival increased in males from 53% for cancers diagnosed between 1989 and 1991 to 58% for those diagnosed between 2001 and 2004. The highest improvement of 10 year survival rates concerned left colon and rectosigmoid junction (+19% in a decade). The progressive set up of national colorectal screening since the early 2000's and the introduction of recent immunological tests in 2015 should decrease the mortality for this cancer and, at term, should decrease its incidence too.

  11. Adiponectin and colorectal cancer.

    PubMed

    Otani, Kensuke; Ishihara, Soichiro; Yamaguchi, Hironori; Murono, Koji; Yasuda, Koji; Nishikawa, Takeshi; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Hata, Keisuke; Kawai, Kazushige; Nozawa, Hiroaki; Watanabe, Toshiaki

    2017-02-01

    Colorectal cancer is an obesity-related malignancy. Adiponectin is an adipokine produced exclusively by adipose tissue, and its concentration in the serum is reduced in obesity. A low serum level of adiponectin is associated with an increased risk of various types of malignancies including colorectal cancer. These facts suggest that the epidemiological link between obesity and cancer may have a significant association with adiponectin. Although numerous studies of colorectal cancer have been reported, the results are conflicting about the anti-cancer effect of adiponectin, and how adiponectin affects carcinogenesis or cancer development remains controversial. Because adiponectin has multiple systemic effects and exists as a high serum concentration protein, the main role of adiponectin should be regulation of homeostasis, and it would not likely act as an anti-cancerous hormone. However, as epidemiological evidence shows, a low adiponectin level may be a basic risk factor for colorectal cancer. We speculate that when the colonic epithelium is stimulated or damaged by another carcinogen under the condition of a low adiponectin level, carcinogenesis is promoted and cancer development is facilitated. In this report, we summarize recent findings of the correlation between adiponectin and colorectal cancer and investigate the effect of adiponectin on colorectal cancer.

  12. Colorectal endometriosis and fertility.

    PubMed

    Daraï, Emile; Cohen, Jonathan; Ballester, Marcos

    2017-02-01

    The goal of this review was to assess the impact of colorectal endometriosis on spontaneous fertility and the potential benefit of Medically Assisted Reproduction (MAR) (in vitro fertilization and intrauterine insemination) and surgery on fertility outcomes. MEDLINE search for articles on fertility in women with DIE published between 1990 and December 2015 using the following terms: "deep endometriosis", "deep infiltrating endometriosis", "bowel endometriosis", "colorectal endometriosis", "fertility", "infertility", "IVF-ICSI", "Assisted Reproductive Techniques (ART)", and "MAR". Spontaneous pregnancy rate (PR) in patients undergoing resection of DIE but leaving in situ colorectal endometriosis was 26.5% (95% CI=14-39). PR after MAR was 27.4% (95% CI=19-35) and the overall PR was 37.9% (95% CI=29-37). After colorectal surgery, among the 855 patients with and without proved infertility, the spontaneous PR was 31.4% (95% CI=28-34) without difference between the groups. PR after MAR was 19.8% (95% CI=17-22). PR after MAR in patients with and without proved infertility was 21.4% (95% CI=18-25) and 15.5% (95% CI=11-20), respectively. The overall PR after colorectal surgery was 51.1% (95% CI=48-54). Our review supports a potential benefit of surgery on fertility outcomes for women with colorectal endometriosis. Further studies are required to determine whether surgical management should be first-intention or restricted to failure of MAR. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. New Molecular Features of Colorectal Cancer Identified - Office of Cancer Clinical Proteomics Research

    Cancer.gov

    Investigators from the National Cancer Institute's Clinical Proteomic Tumor Analysis Consortium (CPTAC) who comprehensively analyzed 95 human colorectal tumor samples, have determined how gene alterations identified in previous analyses of the same samples

  14. Transportability

    DTIC Science & Technology

    2013-04-25

    psi). (g) Maximum axle load (pneumatic tires) - 2,268 kg (5,000 lb). (h) Maximum wheel load (pneumatic tires) - 1,134 kg (2,500 lb). (i...survivability following the shock or vibration environment induced. Vehicles not typically transported with payload such as wreckers, truck tractors ...combination weight rating (GCWR) means the value specified by the manufacturer as the loaded weight of the combination vehicle. (d) Gross axle weight

  15. Transportation

    DTIC Science & Technology

    2007-01-01

    International (cont.) European Commission – Directorate General for Energy and Transport, Brussels, Belgium Headquarters Netherlands Customs ...100,000 by 2014. As a result of these challenges and due to the increase in intermodal freight traffic, a customer /client relationship has...increase by 50% domestically and 110% internationally by 2016 (CRS, 2007). United Parcel Service (UPS), FedEx, and DHL currently control the package

  16. The altered glucose metabolism in tumor and a tumor acidic microenvironment associated with extracellular matrix metalloproteinase inducer and monocarboxylate transporters

    PubMed Central

    Li, Xiaofeng; Yu, Xiaozhou; Dai, Dong; Song, Xiuyu; Xu, Wengui

    2016-01-01

    Extracellular matrix metalloproteinase inducer, also knowns as cluster of differentiation 147 (CD147) or basigin, is a widely distributed cell surface glycoprotein that is involved in numerous physiological and pathological functions, especially in tumor invasion and metastasis. Monocarboxylate transporters (MCTs) catalyze the proton-linked transport of monocarboxylates such as L-lactate across the plasma membrane to preserve the intracellular pH and maintain cell homeostasis. As a chaperone to some MCT isoforms, CD147 overexpression significantly contributes to the metabolic transformation of tumor. This overexpression is characterized by accelerated aerobic glycolysis and lactate efflux, and it eventually provides the tumor cells with a metabolic advantage and an invasive phenotype in the acidic tumor microenvironment. This review highlights the roles of CD147 and MCTs in tumor cell metabolism and the associated molecular mechanisms. The regulation of CD147 and MCTs may prove to be with a therapeutic potential for tumors through the metabolic modification of the tumor microenvironment. PMID:27009812

  17. [Alteration of transport activity of proton pumps in coleoptile cells during early development stages of maize seedlings].

    PubMed

    Shishova, M F; Tankeliun, O V; Rudashevskaia, E L; Emel'ianov, V V; Shakhova, N V; Kirpichnikova, A A

    2012-01-01

    Comparative analysis of the transport activity of proton pumps (plasmalemma H+-ATPase, vacuolar H+-ATPase, and vacuolar H+-pyrophosphatase) in the membrane preparations obtained from coleoptile cells ofetiolated maize seedlings (Zea mays L.) was carried out. The highest level ofvacuolar pyrophosphatase activity was observed during the early development of coleoptile cells under growth intensification through the elongation. The role of ATPase pumps of tonoplast and plasmalemma in the transport of hydrogen ions increases during further development. The plasmalemma activity in this process is higher. When the growth stops, the activity of proton pumps becomes significantly lower. Nevertheless, their substrate specificity and sensitivity to proton pump inhibitors do not change, which can be an evidence of physiological significance of pumps in the maintenance of cell homeostasis.

  18. Neurological effects of inorganic arsenic exposure: altered cysteine/glutamate transport, NMDA expression and spatial memory impairment

    PubMed Central

    Ramos-Chávez, Lucio A.; Rendón-López, Christian R. R.; Zepeda, Angélica; Silva-Adaya, Daniela; Del Razo, Luz M.; Gonsebatt, María E.

    2015-01-01

    Inorganic arsenic (iAs) is an important natural pollutant. Millions of individuals worldwide drink water with high levels of iAs. Chronic exposure to iAs has been associated with lower IQ and learning disabilities as well as memory impairment. iAs is methylated in tissues such as the brain generating mono and dimethylated species. iAs methylation requires cellular glutathione (GSH), which is the main antioxidant in the central nervous system (CNS). In humans, As species cross the placenta and are found in cord blood. A CD1 mouse model was used to investigate effects of gestational iAs exposure which can lead to oxidative damage, disrupted cysteine/glutamate transport and its putative impact in learning and memory. On postnatal days (PNDs) 1, 15 and 90, the expression of membrane transporters related to GSH synthesis and glutamate transport and toxicity, such as xCT, EAAC1, GLAST and GLT1, as well as LAT1, were analyzed. Also, the expression of the glutamate receptor N-methyl-D-aspartate (NMDAR) subunits NR2A and B as well as the presence of As species in cortex and hippocampus were investigated. On PND 90, an object location task was performed to associate exposure with memory impairment. Gestational exposure to iAs affected the expression of cysteine/glutamate transporters in cortex and hippocampus and induced a negative modulation of NMDAR NR2B subunit in the hippocampus. Behavioral tasks showed significant spatial memory impairment in males while the effect was marginal in females. PMID:25709567

  19. Kinetic compartmental analysis of carnitine metabolism in the human carnitine deficiency syndromes. Evidence for alterations in tissue carnitine transport

    SciTech Connect

    Rebouche, C.J.; Engel, A.G.

    1984-03-01

    The human primary carnitine deficiency syndromes are potentially fatal disorders affecting children and adults. The molecular etiologies of these syndromes have not been determined. In this investigation, we considered the hypothesis that these syndromes result from defective transport of carnitine into tissues, particularly skeletal muscle. The problem was approached by mathematical modeling, by using the technique of kinetic compartmental analysis. A tracer dose of L-(methyl-3H)carnitine was administered intravenously to six normal subjects, one patient with primary muscle carnitine deficiency (MCD), and four patients with primary systemic carnitine deficiency (SCD). Specific radioactivity was followed in plasma for 28 d. A three-compartment model (extracellular fluid, muscle, and ''other tissues'') was adopted. Rate constants, fluxes, pool sizes, and turnover times were calculated. Results of these calculations indicated reduced transport of carnitine into muscle in both forms of primary carnitine deficiency. However, in SCD, the reduced rate of carnitine transport was attributed to reduced plasma carnitine concentration. In MCD, the results are consistent with an intrinsic defect in the transport process. Abnormal fluctuations of the plasma carnitine, but of a different form, occurred in MCD and SCD. The significance of these are unclear, but in SCD they suggest abnormal regulation of the muscle/plasma carnitine concentration gradient. In 8 of 11 subjects, carnitine excretion was less than dietary carnitine intake. Carnitine excretion rates calculated by kinetic compartmental analysis were higher than corresponding rates measured directly, indicating degradation of carnitine. However, we found no radioactive metabolites of L-(methyl-3H)carnitine in urine. These observations suggest that dietary carnitine was metabolized in the gastrointestinal tract.

  20. Thyroid-induced alterations in myocardial sodium-potassium-activated adenosine triphosphatase, monovalent cation active transport, and cardiac glycoside binding.

    PubMed Central

    Curfman, G D; Crowley, T J; Smith, T W

    1977-01-01

    The effects of thyroid hormone on guinea pig myocardial NaK-ATPase activity, transmembrane monovalent cation active transport, and cardiac glycoside binding were were examined. NaK-ATPase activities of left atrial and left ventricular homogenates of control and triiodothyronine (T3)-treated animals were determined, and compared to activities of skeletal muscle and liver. T3 administration was associated with a significant increase of 18% in left atrial and left ventricular NaK-ATPase specific activities. This increment was less than that noted in skeletal muscle (+42%) and liver (+30%). To determine if enhanced NaK-ATPase activity was accompanied by increased monovalent cation active transport, in vitro 86Rb+ uptake by left atrial strips and hemidiaphragms was measured. Transition from the euthyroid to the hyperthyroid state resulted in a 68% increase in active 86Rb+ uptake by left atrium, and a 62% increase in active uptake by diaphragm. Passive 86Rb+ uptake was not affected in either tissue. Ouabain binding by atrial and ventricular homogenates of T3-treated animals was increased by 19 and 17%, respectively, compared to controls, in close agreement with thyroid-induced increments in NaK-ATPase activiey. Taken together, these results are consistent with enhanced myocardial NaK-ATPase activity and monovalent cation activt transport due to an increase in the number of functional enzyme complexes. PMID:138689

  1. Ca sup 2+ transport in membrane vesicles from pinto bean leaves and its alteration after ozone exposure. [Phaseolus vulgaris

    SciTech Connect

    Castillo, F.J.; Heath, R.L. )

    1990-10-01

    The influence of ozone on Ca{sup 2+} transport in plant membranes from pinto bean (Phaseolus vulgaris L. var Pinto) leaves was investigated in vitro by means of a filtration method using purified vesicles. Two transport mechanisms located at the plasma membrane are involved in a response to ozone: (a) passive Ca{sup 2+} influx into the cell and (b) active Ca{sup 2+} efflux driven by an ATP-dependent system, which has two components: a primary Ca{sup 2+} transport directly linked to ATP which is partially activated by calmodulin and a H{sup +}/Ca{sup 2+} antiport coupled to activity of a H{sup +}-ATPase. The passive Ca{sup 2+} permeability is increased by ozone. A triangular pulse of ozone stimulates a higher influx of Ca{sup 2+} than does a square wave, even though the total dose with the same (0.6 microliter per liter {times} hour). Leaves exposed to a square wave did not exhibit visible injury and were still able to recover from oxidant stress by activation of calmodulin-dependent Ca{sup 2+} extrusion mechanisms. On the other hand, leaves exposed to a triangular wave of ozone, exhibit visible injury and lost the ability of extruding Ca{sup 2+} out of the cell.

  2. Modulation of OATP1B-type Transporter Function Alters Cellular Uptake and Disposition of Platinum Chemotherapeutics

    PubMed Central

    Lancaster, Cynthia S.; Sprowl, Jason A.; Walker, Aisha L.; Hu, Shuiying; Gibson, Alice A.; Sparreboom, Alex

    2013-01-01

    Expression of the human organic anion transporting polypeptides OATP1B1 and OATP1B3 have been previously believed to be restricted to hepatocytes. Here we demonstrate that the gene encoding OATP1B3, but not OATP1B1, is abundantly expressed in multiple human solid tumors that include hepatocellular, lung, and ovarian carcinomas. Surprisingly, OATP1B3 expression in a panel of 60 human tumor cell lines was linked with sensitivity to multiple cytotoxic agents, including the platinum anticancer drugs cisplatin, carboplatin, and oxaliplatin. In addition, overexpression of OATP1B3 in mammalian cells increased cellular accumulation of platinum agents and decreased cell survival. In mice with a targeted disruption of the ortholog transporter Oatp1b2, the liver-to-plasma ratio of cisplatin was significantly reduced compared with wildtype mice, without concurrent changes in expression profiles of other transporter genes. Our findings indicate an unexpected role for tumoral and host OATP1B-type carriers in the toxicity and disposition of platinum anticancer drugs, and may provide a foundation for understanding the extensive interindividual pharmacodynamic variability seen with these drugs in patients. PMID:23757163

  3. The Novel Membrane-Bound Proteins MFSD1 and MFSD3 are Putative SLC Transporters Affected by Altered Nutrient Intake.

    PubMed

    Perland, Emelie; Hellsten, Sofie V; Lekholm, Emilia; Eriksson, Mikaela M; Arapi, Vasiliki; Fredriksson, Robert

    2017-02-01

    Membrane-bound solute carriers (SLCs) are essential as they maintain several physiological functions, such as nutrient uptake, ion transport and waste removal. The SLC family comprise about 400 transporters, and we have identified two new putative family members, major facilitator superfamily domain containing 1 (MFSD1) and 3 (MFSD3). They cluster phylogenetically with SLCs of MFS type, and both proteins are conserved in chordates, while MFSD1 is also found in fruit fly. Based on homology modelling, we predict 12 transmembrane regions, a common feature for MFS transporters. The genes are expressed in abundance in mice, with specific protein staining along the plasma membrane in neurons. Depriving mouse embryonic primary cortex cells of amino acids resulted in upregulation of Mfsd1, whereas Mfsd3 is unaltered. Furthermore, in vivo, Mfsd1 and Mfsd3 are downregulated in anterior brain sections in mice subjected to starvation, while upregulated specifically in brainstem. Mfsd3 is also attenuated in cerebellum after starvation. In mice raised on high-fat diet, Mfsd1 was specifically downregulated in brainstem and hypothalamus, while Mfsd3 was reduced consistently throughout the brain.

  4. Mammary gland copper transport is stimulated by prolactin through alterations in Ctr1 and Atp7A localization.

    PubMed

    Kelleher, Shannon L; Lönnerdal, Bo

    2006-10-01

    Milk copper (Cu) concentration declines and directly reflects the stage of lactation. Three Cu-specific transporters (Ctr1, Atp7A, Atp7B) have been identified in the mammary gland; however, the integrated role they play in milk Cu secretion is not understood. Whereas the regulation of milk composition by the lactogenic hormone prolactin (PRL) has been documented, the specific contribution of PRL to this process is largely unknown. Using the lactating rat as a model, we determined that the normal decline in milk Cu concentration parallels declining Cu availability to the mammary gland and is associated with decreased Atp7B protein levels. Mammary gland Cu transport was highest during early lactation and was stimulated by suckling and hyperprolactinemia, which was associated with Ctr1 and Atp7A localization at the plasma membrane. Using cultured mammary epithelial cells (HC11), we demonstrated that Ctr1 stains in association with intracellular vesicles that partially colocalize with transferrin receptor (recycling endosome marker). Atp7A was primarily colocalized with mannose 6-phosphate receptor (M6PR; late endosome marker), whereas Atp7B was partially colocalized with protein disulfide isomerase (endoplasmic reticulum marker), TGN38 (trans-Golgi network marker) and M6PR. Prolactin stimulated Cu transport as a result of increased Ctr1 and Atp7A abundance at the plasma membrane. Although the molecular mechanisms responsible for these posttranslational changes are not understood, transient changes in prolactin signaling play a role in the regulation of mammary gland Cu secretion during lactation.

  5. Pre-weaning manganese exposure causes hyperactivity, disinhibition, and spatial learning and memory deficits associated with altered dopamine receptor and transporter levels

    PubMed Central

    Kern, Cynthia; Stanwood, Gregg; Smith, Donald R.

    2009-01-01

    Epidemiological studies in children have reported associations between elevated dietary manganese (Mn) exposure and neurobehavioral and neurocognitive deficits. To better understand the relationship between early Mn exposure and neurobehavioral deficits, we treated neonate rats with oral Mn doses of 0, 25, or 50 mg Mn/kg/d over postnatal day (PND) 1 – 21, and evaluated behavioral performance using open arena (PND 23), elevated plus maze (PND 23), and 8-arm radial maze (PND 33–46) paradigms. Brain dopamine D1 and D2-like receptors, and DAT transporter densities were determined on PND 24, and blood and brain Mn levels were measured to coincide with behavioral testing (PND 24, PND 36). Pre-weaning Mn exposure caused hyperactivity and behavioral disinhibition in the open arena, but no altered behavior in the elevated plus maze. Manganese-exposed males committed significantly more reference and marginally more working errors in the radial arm maze compared to controls. Fewer Mn exposed males achieved the radial maze learning criterion, and they required more session days to reach it compared to controls. Manganese-exposed animals also exhibited a greater frequency of stereotypic response strategy in searching for the baited arms in the maze. These behavioral and learning deficits were associated with altered expression of the dopamine D1 and D2 receptors and the dopamine transporter in prefrontal cortex, nucleus accumbens, and dorsal striatum. These data corroborate epidemiological studies in children, and suggest that exposure to Mn during neurodevelopment significantly alters dopaminergic synaptic environments in brain nuclei that mediate control of executive function behaviors, such as reactivity and cognitive flexibility. PMID:20029834

  6. Colorectal Cancer Risk Assessment Tool

    MedlinePlus

    ... Colorectal Cancer Risk Factors Download SAS and Gauss Code Page Options Print Page Quick Links Colon and Rectal Cancer Home Page Colon and Rectal Cancer: Prevention, Genetics, Causes Tests to Detect Colorectal Cancer and Polyps ...

  7. 6 Common Cancers - Colorectal Cancer

    MedlinePlus

    ... Bar Home Current Issue Past Issues 6 Common Cancers - Colorectal Cancer Past Issues / Spring 2007 Table of Contents For ... colon cancer. Photo: AP Photo/Ron Edmonds Colorectal Cancer Cancer of the colon (large intestine) or rectum ( ...

  8. Colorectal Cancer: Symptoms, Diagnosis, Treatment

    MedlinePlus

    ... Past Issues Special Section: Colorectal Cancer Colorectal Cancer: Symptoms, Diagnosis and Treatment Past Issues / Spring 2009 Table of ... version of this page please turn Javascript on. Symptoms Check with your healthcare provider if you have ...

  9. Altered Transport and Metabolism of Phenolic Compounds in Obesity and Diabetes: Implications for Functional Food Development and Assessment.

    PubMed

    Redan, Benjamin W; Buhman, Kimberly K; Novotny, Janet A; Ferruzzi, Mario G

    2016-11-01

    Interest in the application of phenolic compounds from the diet or supplements for the prevention of chronic diseases has grown substantially, but the efficacy of such approaches in humans is largely dependent on the bioavailability and metabolism of these compounds. Although food and dietary factors have been the focus of intense investigation, the impact of disease states such as obesity or diabetes on their absorption, metabolism, and eventual efficacy is important to consider. These factors must be understood in order to develop effective strategies that leverage bioactive phenolic compounds for the prevention of chronic disease. The goal of this review is to discuss the inducible metabolic systems that may be influenced by disease states and how these effects impact the bioavailability and metabolism of dietary phenolic compounds. Because current studies generally report that obesity and/or diabetes alter the absorption and excretion of these compounds, this review includes a description of the absorption, conjugation, and excretion pathways for phenolic compounds and how they are potentially altered in disease states. A possible mechanism that will be discussed related to the modulation of phenolic bioavailability and metabolism may be linked to increased inflammatory status from increased amounts of adipose tissue or elevated plasma glucose concentrations. Although more studies are needed, the translation of benefits derived from dietary phenolic compounds to individuals with obesity or diabetes may require the consideration of dosing strategies or be accompanied by adjunct therapies to improve the bioavailability of these compounds.

  10. Calcium channel blockers ameliorate iron overload-associated hepatic fibrosis by altering iron transport and stellate cell apoptosis.

    PubMed

    Zhang, Ying; Zhao, Xin; Chang, Yanzhong; Zhang, Yuanyuan; Chu, Xi; Zhang, Xuan; Liu, Zhenyi; Guo, Hui; Wang, Na; Gao, Yonggang; Zhang, Jianping; Chu, Li

    2016-06-15

    Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n=8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Body image concerns after colorectal cancer surgery.

    PubMed

    Taylor, Claire

    Body image is understood to be a person's perception of his or her own physical appearance although, as this article highlights, it embraces a greater range of bodily attributes than is often appreciated. It can be significantly affected by a diagnosis of colorectal cancer and subsequent treatment, which may modify the way the body looks, feels and functions. One of the major aesthetic and functional consequences of colorectal cancer surgery is the possibility of stoma formation, which is of particular concern to many. However, the range of other bodily effects following surgery should not be overlooked, not least because of they may result in distress. While concerns about changes in body image generally decrease over time, people recovering from cancer treatment often feel their relationship with their body has been permanently altered. Specialist support is often required when adjusting to any changes in bodily appearance and function. Care outcomes can be improved by having a sound understanding of the body image concerns likely to arise following treatment, as well as the skills to identify and support patients at risk of altered body image. This article provides guidance to nurses caring for individuals who may be experiencing distress over how their body is now perceived by themselves and others following colorectal cancer surgery.

  12. A Bed Load Monitoring System for Real Time Sediment Transport and Bed Morphology during Channel Altering Events

    NASA Astrophysics Data System (ADS)

    Curran, J. C.; Waters, K. A.; Cannatelli, K.

    2014-12-01

    A new technique is presented that provides continuous measurement of sediment movement over the length of a flume. Real-time measurements of bed changes over a reach are a missing piece needed to link bed morphology with sediment transport processes during unsteady flows when the bed adjusts quickly to changing transport rates or visual observation of the bed is precluded by fine sediment in the water column. A bed load monitoring system (BLMS) was developed that records the sediment and water loads over discrete bed lengths throughout a flow event. It was designed for laboratory application where controlled measurement methods are possible. Upon data processing, the BLMS provides a continuous measure of the sediment load across the bed from which sediment movement rates through the reach, including areas of temporary aggradation or degradation, can be reconstructed. Examples are provided of how the bed load monitoring system has been applied during sediment feed and sediment recirculation experiments to further the interpretation of channel processes occurring during large flows. We detail the use of the BLMS to measure bed slopes during unsteady flows and to measure the movement of sediment downstream following different methods of dam removal. We evaluate the BLMS for use where DEM differencing was also applied to illustrate the information provided by each measurement method. Exciting implications of future research that incorporates a BLMS include a more informed management of river systems as a result of improved temporal predictions of sediment movement and the associated changes in channel slope and morphology.

  13. A polymorphism in the norepinephrine transporter gene alters promoter activity and is associated with attention-deficit hyperactivity disorder

    PubMed Central

    Kim, Chun-Hyung; Hahn, Maureen K.; Joung, Yoosook; Anderson, Susan L.; Steele, Angela H.; Mazei-Robinson, Michelle S.; Gizer, Ian; Teicher, Martin H.; Cohen, Bruce M.; Robertson, David; Waldman, Irwin D.; Blakely, Randy D.; Kim, Kwang-Soo

    2006-01-01

    The norepinephrine transporter critically regulates both neurotransmission and homeostasis of norepinephrine in the nervous system. In this study, we report a previously uncharacterized and common A/T polymorphism at −3081 upstream of the transcription initiation site of the human norepinephrine transporter gene [solute carrier family 6, member 2 (SLC6A2)]. Using both homologous and heterologous promoter-reporter constructs, we found that the −3081(T) allele significantly decreases promoter function compared with the A allele. Interestingly, this T allele creates a new palindromic E2-box motif that interacts with Slug and Scratch, neural-expressed transcriptional repressors binding to the E2-box motif. We also found that both Slug and Scratch repress the SLC6A2 promoter activity only when it contains the T allele. Finally, we observed a significant association between the −3081(A/T) polymorphism and attention-deficit hyperactivity disorder (ADHD), suggesting that anomalous transcription factor-based repression of SLC6A2 may increase risk for the development of attention-deficit hyperactivity disorder and other neuropsychiatric diseases. PMID:17146058

  14. Developments in Colorectal Cancer Screening

    MedlinePlus

    ... tested at age 45. Read More "Colorectal Cancer" Articles Colorectal Cancer: A Personal Journey / The Importance of Early Detection / Developments in Colorectal Cancer Screening Summer 2016 Issue: Volume 11 Number 2 Page ... Us | Viewers & Players Friends of the National Library of Medicine (FNLM)

  15. Colorectal Cancer: A Personal Journey

    MedlinePlus

    ... detection is early cure!” Read More "Colorectal Cancer" Articles Colorectal Cancer: A Personal Journey / The Importance of Early Detection / Developments in Colorectal Cancer Screening Summer 2016 Issue: Volume 11 Number 2 Page ... Us | Viewers & Players Friends of the National Library of Medicine (FNLM)

  16. The impact of ornithogenic inputs on phosphorous transport from altered wetland soils to waterways in East Mediterranean ecosystem.

    PubMed

    Litaor, M Iggy; Reichmann, O; Dente, E; Naftaly, A; Shenker, M

    2014-03-01

    Large flocks of Eurasian crane (Grus grus, >35,000) have begun wintering in an altered wetland agro-ecosystem located in Northern Israel, a phenomenon that attracts more than 400,000 eco-tourists a year. A 100-ha plot has been used to feed the cranes in order to protect nearby fields. The objective of this study was to evaluate the influence of this bird's feeding practice on the P status of the altered wetland soils and waterways. We installed a series of wells at two depths (40 and 90 cm) between two major waterways in the feeding area and monitored the hydraulic heads and collected groundwater samples for elemental analyses. We collected six soil cores and four sediment samples from the waterways and conducted sequential P extraction. We found significant increase in groundwater soluble reactive P (SRP) (>0.5 mg l(-1)) compared with much lower concentrations (~0.06 mg l(-1)) collected in the period prior to the feeding. We found significant decrease in Fe((II)), Ca, and SO4 concentrations in the shallow groundwater (33, 208, and 213 mg l(-1), respectively) compared with the period prior to the feeding (47, 460, and 370 mg l(-1) respectively). An increase in the more labile P fraction was observed in soils and sediments compared with the period before the feeding. The P input by bird excrement to the feeding area was estimated around 700 kg P per season, while P removal by plant harvesting was estimated around 640 kg Pyr(-1). This finding supports the current eco-tourism practices in the middle of intensive farming area, suggesting little impact on waterways. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Obesity and age-related alterations in the gene expression of zinc-transporter proteins in the human brain

    PubMed Central

    Olesen, R H; Hyde, T M; Kleinman, J E; Smidt, K; Rungby, J; Larsen, A

    2016-01-01

    The incidence of Alzheimer's disease (AD) is increasing. Major risk factors for AD are advancing age and diabetes. Lately, obesity has been associated with an increased risk of dementia. Obese and diabetic individuals are prone to decreased circulating levels of zinc, reducing the amount of zinc available for crucial intracellular processes. In the brain, zinc co-localizes with glutamate in synaptic vesicles, and modulates NMDA receptor activity. Intracellular zinc is involved in apoptosis and fluctuations in cytoplasmic Zn2+ affect modulation of intracellular signaling. The ZNT and ZIP proteins participate in intracellular zinc homeostasis. Altered expression of zinc-regulatory proteins has been described in AD patients. Using microarray data from human frontal cortex (BrainCloud), this study investigates expression of the SCLA30A (ZNT) and SCLA39A (ZIP) families of genes in a Caucasian and African-American sample of 145 neurologically and psychiatrically normal individuals. Expression of ZNT3 and ZNT4 were significantly reduced with increasing age, whereas expression of ZIP1, ZIP9 and ZIP13 were significantly increased. Increasing body mass index (BMI) correlated with a significant reduction in ZNT1 expression similar to what is seen in the early stages of AD. Increasing BMI also correlated with reduced expression of ZNT6. In conclusion, we found that the expression of genes that regulate intracellular zinc homeostasis in the human frontal cortex is altered with increasing age and affected by increasing BMI. With the increasing rates of obesity throughout the world, these findings warrant continuous scrutiny of the long-term consequences of obesity on brain function and the development of neurodegenerative diseases. PMID:27300264

  18. Obesity and age-related alterations in the gene expression of zinc-transporter proteins in the human brain.

    PubMed

    Olesen, R H; Hyde, T M; Kleinman, J E; Smidt, K; Rungby, J; Larsen, A

    2016-06-14

    The incidence of Alzheimer's disease (AD) is increasing. Major risk factors for AD are advancing age and diabetes. Lately, obesity has been associated with an increased risk of dementia. Obese and diabetic individuals are prone to decreased circulating levels of zinc, reducing the amount of zinc available for crucial intracellular processes. In the brain, zinc co-localizes with glutamate in synaptic vesicles, and modulates NMDA receptor activity. Intracellular zinc is involved in apoptosis and fluctuations in cytoplasmic Zn(2+) affect modulation of intracellular signaling. The ZNT and ZIP proteins participate in intracellular zinc homeostasis. Altered expression of zinc-regulatory proteins has been described in AD patients. Using microarray data from human frontal cortex (BrainCloud), this study investigates expression of the SCLA30A (ZNT) and SCLA39A (ZIP) families of genes in a Caucasian and African-American sample of 145 neurologically and psychiatrically normal individuals. Expression of ZNT3 and ZNT4 were significantly reduced with increasing age, whereas expression of ZIP1, ZIP9 and ZIP13 were significantly increased. Increasing body mass index (BMI) correlated with a significant reduction in ZNT1 expression similar to what is seen in the early stages of AD. Increasing BMI also correlated with reduced expression of ZNT6. In conclusion, we found that the expression of genes that regulate intracellular zinc homeostasis in the human frontal cortex is altered with increasing age and affected by increasing BMI. With the increasing rates of obesity throughout the world, these findings warrant continuous scrutiny of the long-term consequences of obesity on brain function and the development of neurodegenerative diseases.

  19. Genetics, Cytogenetics, and Epigenetics of Colorectal Cancer

    PubMed Central

    Migliore, Lucia; Migheli, Francesca; Spisni, Roberto; Coppedè, Fabio

    2011-01-01

    Most of the colorectal cancer (CRC) cases are sporadic, only 25% of the patients have a family history of the disease, and major genes causing syndromes predisposing to CRC only account for 5-6% of the total cases. The following subtypes can be recognized: MIN (microsatellite instability), CIN (chromosomal instability), and CIMP (CpG island methylator phenotype). CIN occurs in 80–85% of CRC. Chromosomal instability proceeds through two major mechanisms, missegregation that results in aneuploidy through the gain or loss of whole chromosomes, and unbalanced structural rearrangements that lead to the loss and/or gain of chromosomal regions. The loss of heterozygosity that occur in the first phases of the CRC cancerogenesis (in particular for the genes on 18q) as well as the alteration of methylation pattern of multiple key genes can drive the development of colorectal cancer by facilitating the acquisition of multiple tumor-associated mutations and the instability phenotype. PMID:21490705

  20. Beta-phenylethylamine alters monoamine transporter function via trace amine-associated receptor 1: implication for modulatory roles of trace amines in brain.

    PubMed

    Xie, Zhihua; Miller, Gregory M

    2008-05-01

    Brain monoamines include common biogenic amines (dopamine, norepinephrine, and serotonin) and trace amines [beta-phenylethylamine (beta-PEA), tyramine, tryptamine, and octopamine]. Common biogenic amines are well established as neurotransmitters, but the roles and functional importance of trace amines remain elusive. Here, we re-evaluated the interaction of trace amines with trace amine-associated receptor 1 (TAAR1) and investigated effects of beta-PEA on monoamine transporter function and influence of monoamine autoreceptors on TAAR1 signaling. We confirmed that TAAR1 was activated by trace amines and demonstrated that TAAR1 activation by beta-PEA significantly inhibited uptake and induced efflux of [3H]dopamine, [3H]norepinephrine, and [3H]serotonin in transfected cells. In brain synaptosomes, beta-PEA significantly inhibited uptake and induced efflux of [3H]dopamine and [3H]serotonin in striatal and [3H]norepinephrine in thalamic synaptosomes of rhesus monkeys and wild-type mice, but it lacked the same effects in synaptosomes of TAAR1 knockout mice. The effect of beta-PEA on efflux was blocked by transporter inhibitors in either the transfected cells or wild-type mouse synaptosomes. We also demonstrated that TAAR1 signaling was not affected by monoamine autoreceptors at exposure to trace amines that we show to have poor binding affinity for the autoreceptors relative to common biogenic amines. These results reveal that beta-PEA alters monoamine transporter function via interacting with TAAR1 but not monoamine autoreceptors. The functional profile of beta-PEA may reveal a common mechanism by which trace amines exert modulatory effects on monoamine transporters in brain.

  1. Single-quantum-dot tracking reveals altered membrane dynamics of an attention-deficit/hyperactivity-disorder-derived dopamine transporter coding variant.

    PubMed

    Kovtun, Oleg; Sakrikar, Dhananjay; Tomlinson, Ian D; Chang, Jerry C; Arzeta-Ferrer, Xochitl; Blakely, Randy D; Rosenthal, Sandra J

    2015-04-15

    The presynaptic, cocaine- and amphetamine-sensitive dopamine (DA) transporter (DAT, SLC6A3) controls the intensity and duration of synaptic dopamine signals by rapid clearance of DA back into presynaptic nerve terminals. Abnormalities in DAT-mediated DA clearance have been linked to a variety of neuropsychiatric disorders, including addiction, autism, and attention deficit/hyperactivity disorder (ADHD). Membrane trafficking of DAT appears to be an important, albeit incompletely understood, post-translational regulatory mechanism; its dysregulation has been recently proposed as a potential risk determinant of these disorders. In this study, we demonstrate a link between an ADHD-associated DAT mutation (Arg615Cys, R615C) and variation on DAT transporter cell surface dynamics, a combination only previously studied with ensemble biochemical and optical approaches that featured limited spatiotemporal resolution. Here, we utilize high-affinity, DAT-specific antagonist-conjugated quantum dot (QD) probes to establish the dynamic mobility of wild-type and mutant DATs at the plasma membrane of living cells. Single DAT-QD complex trajectory analysis revealed that the DAT 615C variant exhibited increased membrane mobility relative to DAT 615R, with diffusion rates comparable to those observed after lipid raft disruption. This phenomenon was accompanied by a loss of transporter mobilization triggered by amphetamine, a common component of ADHD medications. Together, our data provides the first dynamic imaging of single DAT proteins, providing new insights into the relationship between surface dynamics and trafficking of both wild-type and disease-associated transporters. Our approach should be generalizable to future studies that explore the possibilities of perturbed surface DAT dynamics that may arise as a consequence of genetic alterations, regulatory changes, and drug use that contribute to the etiology or treatment of neuropsychiatric disorders.

  2. Age-related alterations in the diffusional transport of amino acids across the human Bruch's-choroid complex

    NASA Astrophysics Data System (ADS)

    Hussain, Ali A.; Rowe, Lisa; Marshall, John

    2002-01-01

    Photoreceptor maintenance is dependent on effective delivery of nutrients from the choroidal circulation by way of the acellular Bruch's membrane and the retinal pigment epithelium. Aging of Bruch's membrane is associated with thickening, increased cross linking of fibers, and deposition of debris culminating in reduced porosity. The present study has investigated the effects of aging on the diffusional transport of eight amino acids across Bruch's membrane in 19 human donors. Diffusion studies were carried out in Ussing chambers, and the amount of time-dependent transfer of amino acids across the preparation was quantified by reverse-phase high-performance liquid chromatography. Diffusion rates for all amino acids showed a significant linear decline with aging of donor. The importance of this reduction in delivery of amino acids is discussed with reference to both normal physiology and age-related macular degeneration.

  3. Metabolism-Induced CaCO 3 Biomineralization During Reactive Transport in a Micromodel: Implications for Porosity Alteration

    DOE PAGES

    Singh, Rajveer; Yoon, Hongkyu; Sanford, Robert A.; ...

    2015-09-08

    We investigated the ability of Pseudomonas stutzeri strain DCP-Ps1 to drive CaCO3 biomineralization in a microfluidic flowcell (i.e., micromodel) that simulates subsurface porous media. Results indicate that CaCO3 precipitation occurs during NO3– reduction with a maximum saturation index (SIcalcite) of ~1.56, but not when NO3– was removed, inactive biomass remained, and pH and alkalinity were adjusted to SIcalcite ~ 1.56. CaCO3 precipitation was promoted by metabolically active cultures of strain DCP-Ps1, which at similar values of SIcalcite, have a more negative surface charge than inactive strain DCP-Ps1. A two-stage NO3– reduction (NO3– → NO2– → N2) pore-scale reactive transport modelmore » was used to evaluate denitrification kinetics, which was observed in the micromodel as upper (NO3– reduction) and lower (NO2– reduction) horizontal zones of biomass growth with CaCO3 precipitation exclusively in the lower zone. Our model results are consistent with two biomass growth regions and indicate that precipitation occurred in the lower zone because the largest increase in pH and alkalinity is associated with NO2– reduction. CaCO3 precipitates typically occupied the entire vertical depth of pores and impacted porosity, permeability, and flow. This study provides a framework for incorporating microbial activity in biogeochemistry models, which often base biomineralization only on SI (caused by biotic or abiotic reactions) and, thereby, underpredict the extent of this complex process. Furthermore, these results have wide-ranging implications for understanding reactive transport in relevance to groundwater remediation, CO2 sequestration, and enhanced oil recovery.« less

  4. A single amino acid alteration in PGR5 confers resistance to antimycin A in cyclic electron transport around PSI.

    PubMed

    Sugimoto, Kazuhiko; Okegawa, Yuki; Tohri, Akihiko; Long, Terri A; Covert, Sarah F; Hisabori, Toru; Shikanai, Toshiharu

    2013-09-01

    In Arabidopsis thaliana, the main route of cyclic electron transport around PSI is sensitive to antimycin A, but the site of inhibition has not been clarified. We discovered that ferredoxin-dependent plastoquinone reduction in ruptured chloroplasts was less sensitive to antimycin A in Arabidopsis that overaccumulated PGR5 (PROTON GRADIENT REGULATION 5) originating from Pinus taeda (PtPGR5) than that in the wild type. Consistent with this in vitro observation, infiltration of antimycin A reduced PSII yields and the non-photochemical quenching (NPQ) of Chl fluorescence in wild-type leaves but not in leaves accumulating PtPGR5. There are eight amino acid differences between PGR5 of Arabidopsis (AtPGR5) and PtPGR5 in their mature forms. To determine the site conferring antimycin A resistance, a series of AtPGR5 and PtPGR5 variants was introduced into the Arabidopsis pgr5 mutant. We determined that the presence of lysine rather than valine at the third amino acid position was necessary and sufficient for resistance to antimycin A. High levels of resistance to antimycin A required overaccumulation of PtPGR5 in ruptured chloroplasts, suggesting that PtPGR5 is partly resistant to antimycin A. In contrast, PSII yield was almost fully resistant to antimycin A in leaves accumulating endogenous levels of PtPGR5 or AtPGR5 V3K that had lysine instead of valine at the third position. NPQ was also dramatically recovered in leaves of these lines. These results imply that partial recovery of PSI cyclic electron transport is sufficient for maintaining redox homeostasis in photosynthesis. Our discovery suggests that antimycin A inhibits the function of PGR5 or proteins localized close to PGR5.

  5. Genetic Polymorphisms in Organic Cation Transporter 1 (OCT1) in Chinese and Japanese Populations Exhibit Altered Function

    PubMed Central

    Chen, Ligong; Takizawa, Miho; Chen, Eugene; Schlessinger, Avner; Segenthelar, Julie; Choi, Ji Ha; Sali, Andej; Kubo, Michiaki; Nakamura, Shinko; Iwamoto, Yasuhiko; Iwasaki, Naoko

    2010-01-01

    Organic cation transporter 1 (OCT1; SLC22A1) seems to play a role in the efficacy and disposition of the widely used antidiabetic drug metformin. Genetic variants in OCT1 have been identified largely in European populations. Metformin is increasingly being used in Asian populations where the incidence of type 2 diabetes (T2D) is on the rise. The goal of this study is to identify genetic variants of OCT1 in Chinese and Japanese populations, which may potentially modulate response to metformin. We used recent data from the 1000 Genomes Project (Chinese and Japanese) and direct sequencing of selected amplicons of OCT1 in 66 DNA samples from Japanese patients with T2D. A total of six nonsynonymous variants were identified. Three of them (Q97K, P117L, and R206C) had not been functionally characterized previously and had allele frequencies of 0.017, 0.023 and 0.008, respectively. The uptake of metformin in cells expressing Q97K, P117L, and R206C was significantly reduced relative to the OCT1 reference (62 ± 4.3, 55 ± 6.8, and 22 ± 1.5% for Q97K, P117L, and R206C, respectively). Kinetic studies indicated that P117L and R206C exhibited a reduced Vmax, whereas Q97K showed an increased Km. The green fluorescent protein (GFP)-tagged Q97K and P117L variants localized to the plasma membrane, whereas the GFP-tagged R206C was retained mainly in the endoplasmic reticulum. Replacement of the highly conserved R206 with different amino acids modulated the subcellular localization and function of the transporter. This study suggests that nonsynonymous variants of OCT1 in Chinese and Japanese populations may affect the differential response to metformin. PMID:20639304

  6. Metabolism-Induced CaCO 3 Biomineralization During Reactive Transport in a Micromodel: Implications for Porosity Alteration

    SciTech Connect

    Singh, Rajveer; Yoon, Hongkyu; Sanford, Robert A.; Katz, Lynn; Fouke, Bruce W.; Werth, Charles J.

    2015-09-08

    We investigated the ability of Pseudomonas stutzeri strain DCP-Ps1 to drive CaCO3 biomineralization in a microfluidic flowcell (i.e., micromodel) that simulates subsurface porous media. Results indicate that CaCO3 precipitation occurs during NO3 reduction with a maximum saturation index (SIcalcite) of ~1.56, but not when NO3 was removed, inactive biomass remained, and pH and alkalinity were adjusted to SIcalcite ~ 1.56. CaCO3 precipitation was promoted by metabolically active cultures of strain DCP-Ps1, which at similar values of SIcalcite, have a more negative surface charge than inactive strain DCP-Ps1. A two-stage NO3 reduction (NO3 → NO2 → N2) pore-scale reactive transport model was used to evaluate denitrification kinetics, which was observed in the micromodel as upper (NO3 reduction) and lower (NO2 reduction) horizontal zones of biomass growth with CaCO3 precipitation exclusively in the lower zone. Our model results are consistent with two biomass growth regions and indicate that precipitation occurred in the lower zone because the largest increase in pH and alkalinity is associated with NO2 reduction. CaCO3 precipitates typically occupied the entire vertical depth of pores and impacted porosity, permeability, and flow. This study provides a framework for incorporating microbial activity in biogeochemistry models, which often base biomineralization only on SI (caused by biotic or abiotic reactions) and, thereby, underpredict the extent of this complex process. Furthermore, these results have wide-ranging implications for understanding reactive transport in relevance to groundwater remediation, CO2 sequestration, and enhanced oil recovery.

  7. How Amazonian deforestation can alter the South American circulation regime: Insights from a non-linear moisture transport model

    NASA Astrophysics Data System (ADS)

    Boers, Niklas; Marwan, Norbert; Barbosa, Henrique; Kurths, Jürgen

    2015-04-01

    A key driver of South American climate are the low-level trade winds from the tropical Atlantic Ocean towards the continent. After crossing the Amazon Basin, they are blocked by the Andes mountain range, and forced southward to the subtropics. These winds are crucial for the atmospheric moisture supply in most parts of South America. In particular, the hydrology of the two largest river basins of the Continent, namely the Amazon and the La Plata Basins, strongly depend on the moisture inflow provided by the trade winds. In turn, the Amazon rainforest can be assumed to have a strong influence on this low-level moisture circulation over South America by exchanging moisture with the atmosphere through precipitation and evapotranspiration. A pronounced positive feedback in this context is established through precipitation-induced release of latent heat over the Amazon Basin, which significantly enhances the moisture inflow from the tropical Atlantic Ocean toward the continent and can thus be considered to be crucial for the existence of today's South American climate. Ongoing deforestation and resulting reduction in evapotranspiration rates in particular in the eastern Amazon carry the risk of a strongly nonlinear response in these interactions with the low-level atmosphere. We propose a simple differential transport model describing the cascading moisture transport from the eastern coast of South America across the Amazon Basin to the Andes, taking into account the nonlinearity associated with the release of latent heat. The results of the model suggest that the system is indeed very sensitive to relatively small reductions of the evapotranspiration rates in the eastern Amazon Basin. These reductions increase river runoff, but limit the moisture availability farther west. This leads to a reduction in precipitation rates and thereby diminishes the release of latent heat which, in turn, reduces the overall moisture inflow. We show that, according to our model, there

  8. Prenatal Exposure to Sodium Arsenite Alters Placental Glucose 1, 3, and 4 Transporters in Balb/c Mice

    PubMed Central

    Gutiérrez-Torres, Daniela Sarahí; González-Horta, Carmen; Del Razo, Luz María; Infante-Ramírez, Rocío; Ramos-Martínez, Ernesto; Levario-Carrillo, Margarita; Sánchez-Ramírez, Blanca

    2015-01-01

    Inorganic arsenic (iAs) exposure induces a decrease in glucose type 4 transporter (GLUT4) expression on the adipocyte membrane, which may be related to premature births and low birth weight infants in women exposed to iAs at reproductive age. The aim of this study was to analyze the effect of sodium arsenite (NaAsO2) exposure on GLUT1, GLUT3, and GLUT4 protein expression and on placental morphology. Female Balb/c mice (n = 15) were exposed to 0, 12, and 20 ppm of NaAsO2 in drinking water from 8th to 18th day of gestation. Morphological changes and GLUT1, GLUT3, and GLUT4 expression were evaluated in placentas by immunohistochemical and image analysis and correlated with iAs and arsenical species concentration, which were quantified by atomic absorption spectroscopy. NaAsO2 exposure induced a significant decrease in fetal and placental weight (P < 0.01) and increases in infarctions and vascular congestion. Whereas GLUT1 expression was unchanged in placentas from exposed group, GLUT3 expression was found increased. In contrast, GLUT4 expression was significantly lower (P < 0.05) in placentas from females exposed to 12 ppm. The decrease in placental GLUT4 expression might affect the provision of adequate fetal nutrition and explain the low fetal weight observed in the exposed groups. PMID:26339590

  9. Altered postnatal development of cortico-hippocampal neuronal electric activity in mice deficient for the mitochondrial aspartate-glutamate transporter.

    PubMed

    Gómez-Galán, Marta; Makarova, Julia; Llorente-Folch, Irene; Saheki, Takeyori; Pardo, Beatriz; Satrústegui, Jorgina; Herreras, Oscar

    2012-02-01

    The deficiency in the mitochondrial aspartate/glutamate transporter Aralar/AGC1 results in a loss of the malate-aspartate NADH shuttle in the brain neurons, hypomyelination, and additional defects in the brain metabolism. We studied the development of cortico/hippocampal local field potential (LFP) in Aralar/AGC1 knockout (KO) mice. Laminar profiles of LFP, evoked potentials, and unit activity were recorded under anesthesia in young (P15 to P22) Aralar-KO and control mice as well as control adults. While LFP power increased 3 to 7 times in both cortex and hippocampus of control animals during P15 to P22, the Aralar-KO specimens hardly progressed. The divergence was more pronounced in the CA3/hilus region. In parallel, spontaneous multiunit activity declined severely in KO mice. Postnatal growth of hippocampal-evoked potentials was delayed in KO mice, and indicated abnormal synaptic and spike electrogenesis and reduced output at P20 to P22. The lack of LFP development in KO mice was accompanied by the gradual appearance of epileptic activity in the CA3/hilus region that evolved to status epilepticus. Strikingly, CA3 bursts were poorly conducted to the CA1 field. We conclude that disturbed substrate supply to neuronal mitochondria impairs development of cortico-hippocampal LFPs. Aberrant neuronal electrogenesis and reduced neuron output may explain circuit dysfunction and phenotype deficiencies.

  10. Altered mRNA transport, docking, and protein translation in neurons lacking fragile X mental retardation protein.

    PubMed

    Kao, Der-I; Aldridge, Georgina M; Weiler, Ivan Jeanne; Greenough, William T

    2010-08-31

    Fragile X syndrome is caused by the absence of functional fragile X mental retardation protein (FMRP), an RNA binding protein. The molecular mechanism of aberrant protein synthesis in fmr1 KO mice is closely associated with the role of FMRP in mRNA transport, delivery, and local protein synthesis. We show that GFP-labeled Fmr1 and CaMKIIalpha mRNAs undergo decelerated motion at 0-40 min after group I mGluR stimulation, and later recover at 40-60 min. Then we investigate targeting of mRNAs associated with FMRP after neuronal stimulation. We find that FMRP is synthesized closely adjacent to stimulated mGluR5 receptors. Moreover, in WT neurons, CaMKIIalpha mRNA can be delivered and translated in dendritic spines within 10 min in response to group I mGluR stimulation, whereas KO neurons fail to show this response. These data suggest that FMRP can mediate spatial mRNA delivery for local protein synthesis in response to synaptic stimulation.

  11. Altered expression of norepinephrine transporter and norepinephrine in human placenta cause pre-eclampsia through regulated trophoblast invasion

    PubMed Central

    Na, Kyu-Hwan; Choi, Jong Ho; Kim, Chun-Hyung; Kim, Kwang-Soo

    2013-01-01

    Objective We investigated the norepinephrine transporter (NET) expression in normal and pre-eclamptic placentas and analyzed the invasion activity of trophoblastic cells based on norepinephrine (NE)-NET regulation. Methods NET and NE expression levels were examined by western blot and enzyme-linked immunosorbent assay, respectively. Trophoblast invasion activity, depending on NE-NET regulation, was determined by NET-small interfering RNA (siRNA) and NET transfection into the human extravillous trophoblast cells with or without NE treatment and invasion rates were analyzed by zymography and an invasion assay. Results NET mRNA was expressed at a low level in pre-eclamptic placentas compared with normal placentas and NE concentration in maternal plasma increased significantly in pre-eclamptic women compared to normal pregnant women (p<0.05). NET gene upregulation and NE treatment stimulated trophoblast cell invasion up to 2.5-fold (p<0.05) by stimulating matrix metalloproteinase-9 activity via the phosphoinositol-3-kinase/AKT signaling pathway, whereas NET-siRNA with NE treatment reduced invasion rates. Conclusion NET expression is reduced by inadequate regulation of NE levels during placental development. This suggests that a complementary balance between NET and NE regulates trophoblast cell invasion activities during placental development. PMID:23614111

  12. Sublethal exposure to azamethiphos causes neurotoxicity, altered energy allocation and high mortality during simulated live transport in American lobster.

    PubMed

    Couillard, C M; Burridge, L E

    2015-05-01

    In the Bay of Fundy, New Brunswick, sea lice outbreaks in caged salmon are treated with pesticides including Salmosan(®), applied as bath treatments and then released into the surrounding seawater. The effect of chronic exposure to low concentrations of this pesticide on neighboring lobster populations is a concern. Adult male lobsters were exposed to 61 ngL(-1) of azamethiphos (a.i. in Salmosan(®) formulation) continuously for 10 days. In addition to the direct effects of pesticide exposure, effects on the ability to cope with shipping conditions and the persistence of the effects after a 24h depuration period in clean seawater were assessed. Indicators of stress and hypoxia (serum total proteins, hemocyanin and lactate), oxidative damage (protein carbonyls in gills and serum) and altered energy allocation (hepatosomatic and gonadosomatic indices, hepatopancreas lipids) were assessed in addition to neurotoxicity (chlolinesterase activity in muscle). Directly after exposure, azamethiphos-treated lobsters had inhibition of muscle cholinesterase, reduced gonadosomatic index and enhanced hepatosomatic index and hepatopancreas lipid content. All these responses persisted after 24-h depuration, increasing the risk of cumulative impacts with further exposure to chemical or non-chemical stressors. In both control and treated lobsters exposed to simulated shipment conditions, concentrations of protein and lactate in serum, and protein carbonyls in gills increased. However, mortality rate was higher in azamethiphos-treated lobsters (33 ± 14%) than in controls (2.6 ± 4%). Shipment and azamethiphos had cumulative impacts on serum proteins. Both direct effects on neurological function and energy allocation and indirect effect on ability to cope with shipping stress could have significant impacts on lobster population and/or fisheries. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  13. G-actin guides p53 nuclear transport: potential contribution of monomeric actin in altered localization of mutant p53

    PubMed Central

    Saha, Taniya; Guha, Deblina; Manna, Argha; Panda, Abir Kumar; Bhat, Jyotsna; Chatterjee, Subhrangsu; Sa, Gaurisankar

    2016-01-01

    p53 preserves genomic integrity by restricting anomaly at the gene level. Till date, limited information is available for cytosol to nuclear shuttling of p53; except microtubule-based trafficking route, which utilizes minus-end directed motor dynein. The present study suggests that monomeric actin (G-actin) guides p53 traffic towards the nucleus. Histidine-tag pull-down assay using purified p53(1–393)-His and G-actin confirms direct physical association between p53 and monomeric G-actin. Co-immunoprecipitation data supports the same. Confocal imaging explores intense perinuclear colocalization between p53 and G-actin. To address atomistic details of the complex, constraint-based docked model of p53:G-actin complex was generated based on crystal structures. MD simulation reveals that p53 DNA-binding domain arrests very well the G-actin protein. Docking benchmark studies have been carried out for a known crystal structure, 1YCS (complex between p53DBD and BP2), which validates the docking protocol we adopted. Co-immunoprecipitation study using “hot-spot” p53 mutants suggested reduced G-actin association with cancer-associated p53 conformational mutants (R175H and R249S). Considering these findings, we hypothesized that point mutation in p53 structure, which diminishes p53:G-actin complexation results in mutant p53 altered subcellular localization. Our model suggests p53Arg249 form polar-contact with Arg357 of G-actin, which upon mutation, destabilizes p53:G-actin interaction and results in cytoplasmic retention of p53R249S. PMID:27601274

  14. The expression profiles of the galectin gene family in colorectal adenocarcinomas.

    PubMed

    Gopalan, Vinod; Saremi, Nassim; Sullivan, Emily; Kabir, Sadiul; Lu, Cu-Tai; Salajegheh, Ali; Leung, Melissa; Smith, Robert Anthony; Lam, Alfred King-Yin

    2016-07-01

    We aim to investigate the expression profiles of galectin family genes (galectins-1, 2, 3, 4, 7, 8, 9, 10, and 11) in colorectal carcinomas. Messenger RNA (mRNA) expression of galectin family members (1, 2, 3, 4, 7, 8, 9, 10, and 12) was analyzed by real-time polymerase chain reaction in colorectal tissues from 201 patients (54 noncancer colorectal tissues, 49 adenomas, and 98 adenocarcinomas). Galectin-1 and galectin-3 protein expressions were determined by immunohistochemistry. In general, high galectin mRNA expression was noted in colorectal carcinomas in early stages of their pathogenesis. Significant differences in galectins-2, 3, 7, 8, and 10 mRNA expression were associated with pathologic stages (P<.05). Increased prevalence of galectins-2, 7, 8, and 10 mRNA overexpression was noted in nonmetastatic colorectal carcinomas (P<.05). Galectin-1 and galectin-3 proteins were present in the nucleus and cytoplasm of the colorectal tissues and expressed significantly higher in colorectal carcinomas when compared to colorectal adenomas (61% and 95%, respectively). Patients with colorectal carcinoma with high levels of galectin-3 mRNA and protein expression showed better prognosis (P=.052). To conclude, many novel correlations between the deregulation of galectin family genes and various clinicopathological features in colorectal adenocarcinoma were noted. Overexpression of galectins at the mRNA level and proteins were predominant in earlier stages of colorectal carcinomas. These altered expression patterns of galectin genes suggest the multifunctional role of galectin genes in the regulation of colorectal cancer development, progression, and metastasis. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Colorectal cancer cell lines lack the molecular heterogeneity of clinical colorectal tumors.

    PubMed

    Auman, James Todd; McLeod, Howard L

    2010-01-01

    Histologically similar colorectal cancers (CRCs) exhibit a wide range of outcomes, suggesting that knowledge of the molecular differences might provide insight into this heterogeneity. Cancer cell lines have been used in preclinical studies to identify gene expression alterations that influence response to chemotherapeutic agents. However, it is not clear to what extent available CRC cell lines reflect the molecular heterogeneity observed in clinical colorectal tumors. We compared genome-wide gene expression data from 22 CRC cell lines and 276 clinical colorectal tumors to determine whether the cell lines were able to represent the variability in expression profiles seen in the clinical tissues. Following mean centered data normalization, hierarchical clustering was performed on the samples using literature-derived biologic and pharmacogenomic gene sets. In general, the majority of cell lines tended to cluster together in a single group, as a subcluster within the clinical tissues, although a few cell lines showed distinct expression profiles from the majority of cell lines. The gene expression data comparison suggests that CRC cell lines do not adequately reflect the molecular heterogeneity of clinical colorectal tumors.

  16. MzPIP2;1: An Aquaporin Involved in Radial Water Movement in Both Water Uptake and Transportation, Altered the Drought and Salt Tolerance of Transgenic Arabidopsis

    PubMed Central

    Lei, Qiong; Feng, Chao; Gao, Yinan; Zheng, Xiaodong; Zhao, Yu; Wang, Zhi; Kong, Jin

    2015-01-01

    Background Plants are unavoidably subjected to various abiotic stressors, including high salinity, drought and low temperature, which results in water deficit and even death. Water uptake and transportation play a critical role in response to these stresses. Many aquaporin proteins, localized at different tissues, function in various transmembrane water movements. We targeted at the key aquaporin in charge of both water uptake in roots and radial water transportation from vascular tissues through the whole plant. Results The MzPIP2;1 gene encoding a plasma membrane intrinsic protein was cloned from salt-tolerant apple rootstock Malus zumi Mats. The GUS gene was driven by MzPIP2;1 promoter in transgenic Arabidopsis. It indicated that MzPIP2;1 might function in the epidermal and vascular cells of roots, parenchyma cells around vessels through the stems and vascular tissues of leaves. The ectopically expressed MzPIP2;1 conferred the transgenic Arabidopsis plants enhanced tolerance to slight salt and drought stresses, but sensitive to moderate salt stress, which was indicated by root length, lateral root number, fresh weight and K+/Na+ ratio. In addition, the possible key cis-elements in response to salt, drought and cold stresses were isolated by the promoter deletion experiment. Conclusion The MzPIP2;1 protein, as a PIP2 aquaporins subgroup member, involved in radial water movement, controls water absorption and usage efficiency and alters transgenic plants drought and salt tolerance. PMID:26562158

  17. MzPIP2;1: An Aquaporin Involved in Radial Water Movement in Both Water Uptake and Transportation, Altered the Drought and Salt Tolerance of Transgenic Arabidopsis.

    PubMed

    Wang, Lin; Li, Qingtian; Lei, Qiong; Feng, Chao; Gao, Yinan; Zheng, Xiaodong; Zhao, Yu; Wang, Zhi; Kong, Jin

    2015-01-01

    Plants are unavoidably subjected to various abiotic stressors, including high salinity, drought and low temperature, which results in water deficit and even death. Water uptake and transportation play a critical role in response to these stresses. Many aquaporin proteins, localized at different tissues, function in various transmembrane water movements. We targeted at the key aquaporin in charge of both water uptake in roots and radial water transportation from vascular tissues through the whole plant. The MzPIP2;1 gene encoding a plasma membrane intrinsic protein was cloned from salt-tolerant apple rootstock Malus zumi Mats. The GUS gene was driven by MzPIP2;1 promoter in transgenic Arabidopsis. It indicated that MzPIP2;1 might function in the epidermal and vascular cells of roots, parenchyma cells around vessels through the stems and vascular tissues of leaves. The ectopically expressed MzPIP2;1 conferred the transgenic Arabidopsis plants enhanced tolerance to slight salt and drought stresses, but sensitive to moderate salt stress, which was indicated by root length, lateral root number, fresh weight and K+/Na+ ratio. In addition, the possible key cis-elements in response to salt, drought and cold stresses were isolated by the promoter deletion experiment. The MzPIP2;1 protein, as a PIP2 aquaporins subgroup member, involved in radial water movement, controls water absorption and usage efficiency and alters transgenic plants drought and salt tolerance.

  18. Prostaglandin E2-induced colonic secretion in patients with and without colorectal neoplasia

    PubMed Central

    2010-01-01

    Background The pathogenesis for colorectal cancer remains unresolved. A growing body of evidence suggests a direct correlation between cyclooxygenase enzyme expression, prostaglandin E2 metabolism and neoplastic development. Thus further understanding of the regulation of epithelial functions by prostaglandin E2 is needed. We hypothesized that patients with colonic neoplasia have altered colonic epithelial ion transport and express functionally different prostanoid receptor levels in this respect. Methods Patients referred for colonoscopy were included and grouped into patients with and without colorectal neoplasia. Patients without endoscopic findings of neoplasia served as controls. Biopsy specimens were obtained from normally appearing mucosa in the sigmoid part of colon. Biopsies were mounted in miniaturized modified Ussing air-suction chambers. Indomethacin (10 μM), various stimulators and inhibitors of prostanoid receptors and ion transport were subsequently added to the chamber solutions. Electrogenic ion transport parameters (short circuit current and slope conductance) were recorded. Tissue pathology and tissue damage before and after experiments was assessed by histology. Results Baseline short circuit current and slope conductance did not differ between the two groups. Patients with neoplasia were significantly more sensitive to indomethacin with a decrease in short circuit current of 15.1 ± 2.6 μA·cm-2 compared to controls, who showed a decrease of 10.5 ± 2.1 μA·cm-2 (p = 0.027). Stimulation or inhibition with theophylline, ouabain, bumetanide, forskolin or the EP receptor agonists prostaglandin E2, butaprost, sulprostone and prostaglandin E1 (OH) did not differ significantly between the two groups. Histology was with normal findings in both groups. Conclusions Epithelial electrogenic transport is more sensitive to indomethacin in normal colonic mucosa from patients with previous or present colorectal neoplasia compared to colonic mucosa from

  19. ER stress in adipocytes inhibits insulin signaling, represses lipolysis, and alters the secretion of adipokines without inhibiting glucose transport.

    PubMed

    Xu, L; Spinas, G A; Niessen, M

    2010-08-01

    The endoplasmic reticulum (ER) is the intra-cellular site, where secreted and membrane proteins are synthesized. ER stress and activation of the unfolded protein response (UPR) contribute to insulin resistance and the development of diabetes in obesity. It was shown previously in hepatocytes that the UPR activates c-jun N-terminal kinase (JNK), which phosphorylates insulin receptor substrate (IRS) proteins on serine residues thereby inhibiting insulin signal transduction. Here we describe how ER stress affects insulin signaling and the biological function of adipocytes. In addition to inhibition of IRS we found that ER stress downregulates the expression of the insulin receptor. Concomitantly, insulin-induced activation of Akt/PKB and of ERK1/2 was strongly inhibited. Ectopic expression of IRS1 or IRS2 strongly counteracted the inhibitory effect of ER stress on insulin signaling while pharmacological inhibition of JNK with SP600125 resulted only in a mild improvement. ER stress decreased the secretion of the adipokines adiponectin and leptin, but strongly increased secretion of IL-6. ER stress inhibited expression and insulin-induced phosphorylation of AS160, reduced lipolysis but did not inhibit glucose transport. Finally, supernatants collected from 3T3-L1 adipocytes undergoing ER stress improved or impaired proliferation when used to condition the culture medium of INS-1E beta-cells dependent on the degree of ER stress. It appears that ER stress in adipocytes might initially lead to changes resembling early prediabetic stages, which at least in part support the regulation of systemic energy homeostasis. Copyright Georg Thieme Verlag KG Stuttgart New York.

  20. Prion Protein (PrP) Knock-Out Mice Show Altered Iron Metabolism: A Functional Role for PrP in Iron Uptake and Transport

    PubMed Central

    Singh, Ajay; Kong, Qingzhong; Luo, Xiu; Petersen, Robert B.; Meyerson, Howard; Singh, Neena

    2009-01-01

    Despite overwhelming evidence implicating the prion protein (PrP) in prion disease pathogenesis, the normal function of this cell surface glycoprotein remains unclear. In previous reports we demonstrated that PrP mediates cellular iron uptake and transport, and aggregation of PrP to the disease causing PrP-scrapie (PrPSc) form results in imbalance of iron homeostasis in prion disease affected human and animal brains. Here, we show that selective deletion of PrP in transgenic mice (PrPKO) alters systemic iron homeostasis as reflected in hematological parameters and levels of total iron and iron regulatory proteins in the plasma, liver, spleen, and brain of PrPKO mice relative to matched wild type controls. Introduction of radiolabeled iron (59FeCl3) to Wt and PrPKO mice by gastric gavage reveals inefficient transport of 59Fe from the duodenum to the blood stream, an early abortive spike of erythropoiesis in the long bones and spleen, and eventual decreased 59Fe content in red blood cells and all major organs of PrPKO mice relative to Wt controls. The iron deficient phenotype of PrPKO mice is reversed by expressing Wt PrP in the PrPKO background, demonstrating a functional role for PrP in iron uptake and transport. Since iron is required for essential metabolic processes and is also potentially toxic if mismanaged, these results suggest that loss of normal function of PrP due to aggregation to the PrPSc form induces imbalance of brain iron homeostasis, resulting in disease associated neurotoxicity. PMID:19568430

  1. Chronic social stress in pigs impairs intestinal barrier and nutrient transporter function, and alters neuro-immune mediator and receptor expression.

    PubMed

    Li, Yihang; Song, Zehe; Kerr, Katelyn A; Moeser, Adam J

    2017-01-01

    Psychosocial stress is a major factor driving gastrointestinal (GI) pathophysiology and disease susceptibility in humans and animals. The mechanisms governing susceptibility to stress-induced GI disease remain poorly understood. In the present study, we investigated the influence of chronic social stress (CSS) in pigs, induced by 7 d of chronic mixing/crowding stress, on intestinal barrier and nutrient transport function, corticotropin releasing factor (CRF) signaling and immunological responses. Results from this study showed that CSS resulted in a significant impairment of ileal and colonic barrier function indicated by reduced transepithelial electrical resistance (TER) in the ileum and increased FD4 flux in the ileum (by 0.8 fold) and colon (by 0.7 fold). Ileal sodium glucose linked transporter 1 (SGLT-1) function, measured as glucose-induced changes in short-circuit current (Isc), was diminished (by 52%) in CSS pigs, associated with reduced body weight gain and feed efficiency. Although reductions in SGLT-1 function were observed in CSS pigs, mRNA expression for SGLT-1, villus heights were increased in CSS pigs. Corticotropin releasing factor (CRF) mRNA was upregulated (by 0.9 fold) in the ileum of CSS pigs but not in the colon. Urocortin 2 (Ucn2) mRNA was upregulated (by 1.5 fold) in the colon of CSS pigs, but not in the ileum. In CSS pigs, a downregulation of pro-inflammatory cytokines mRNA (IL1B, TNFA, IL8, and IL6) was observed in both ileum and colon, compared with controls. In contrast CSS induced a marked upregulation of mRNA for IL10 and mast cell chymase gene (CMA1) in the ileum and colon. Together, these data demonstrate that chronic stress in pigs results in significant alterations in intestinal barrier and nutrient transport function and neuro-immune mediator and receptor expression.

  2. Increased Activity of the Vacuolar Monosaccharide Transporter TMT1 Alters Cellular Sugar Partitioning, Sugar Signaling, and Seed Yield in Arabidopsis1[OA

    PubMed Central

    Wingenter, Karina; Schulz, Alexander; Wormit, Alexandra; Wic, Stefan; Trentmann, Oliver; Hoermiller, Imke I.; Heyer, Arnd G.; Marten, Irene; Hedrich, Rainer; Neuhaus, H. Ekkehard

    2010-01-01

    The extent to which vacuolar sugar transport activity affects molecular, cellular, and developmental processes in Arabidopsis (Arabidopsis thaliana) is unknown. Electrophysiological analysis revealed that overexpression of the tonoplast monosaccharide transporter TMT1 in a tmt1-2::tDNA mutant led to increased proton-coupled monosaccharide import into isolated mesophyll vacuoles in comparison with wild-type vacuoles. TMT1 overexpressor mutants grew faster than wild-type plants on soil and in high-glucose (Glc)-containing liquid medium. These effects were correlated with increased vacuolar monosaccharide compartmentation, as revealed by nonaqueous fractionation and by chlorophyllab-binding protein1 and nitrate reductase1 gene expression studies. Soil-grown TMT1 overexpressor plants respired less Glc than wild-type plants and only about half the amount of Glc respired by tmt1-2::tDNA mutants. In sum, these data show that TMT activity in wild-type plants limits vacuolar monosaccharide loading. Remarkably, TMT1 overexpressor mutants produced larger seeds and greater total seed yield, which was associated with increased lipid and protein content. These changes in seed properties were correlated with slightly decreased nocturnal CO2 release and increased sugar export rates from detached source leaves. The SUC2 gene, which codes for a sucrose transporter that may be critical for phloem loading in leaves, has been identified as Glc repressed. Thus, the observation that SUC2 mRNA increased slightly in TMT1 overexpressor leaves, characterized by lowered cytosolic Glc levels than wild-type leaves, provided further evidence of a stimulated source capacity. In summary, increased TMT activity in Arabidopsis induced modified subcellular sugar compartmentation, altered cellular sugar sensing, affected assimilate allocation, increased the biomass of Arabidopsis seeds, and accelerated early plant development. PMID:20709831

  3. Chronic social stress in pigs impairs intestinal barrier and nutrient transporter function, and alters neuro-immune mediator and receptor expression

    PubMed Central

    Li, Yihang; Song, Zehe; Kerr, Katelyn A.; Moeser, Adam J.

    2017-01-01

    Psychosocial stress is a major factor driving gastrointestinal (GI) pathophysiology and disease susceptibility in humans and animals. The mechanisms governing susceptibility to stress-induced GI disease remain poorly understood. In the present study, we investigated the influence of chronic social stress (CSS) in pigs, induced by 7 d of chronic mixing/crowding stress, on intestinal barrier and nutrient transport function, corticotropin releasing factor (CRF) signaling and immunological responses. Results from this study showed that CSS resulted in a significant impairment of ileal and colonic barrier function indicated by reduced transepithelial electrical resistance (TER) in the ileum and increased FD4 flux in the ileum (by 0.8 fold) and colon (by 0.7 fold). Ileal sodium glucose linked transporter 1 (SGLT-1) function, measured as glucose-induced changes in short-circuit current (Isc), was diminished (by 52%) in CSS pigs, associated with reduced body weight gain and feed efficiency. Although reductions in SGLT-1 function were observed in CSS pigs, mRNA expression for SGLT-1, villus heights were increased in CSS pigs. Corticotropin releasing factor (CRF) mRNA was upregulated (by 0.9 fold) in the ileum of CSS pigs but not in the colon. Urocortin 2 (Ucn2) mRNA was upregulated (by 1.5 fold) in the colon of CSS pigs, but not in the ileum. In CSS pigs, a downregulation of pro-inflammatory cytokines mRNA (IL1B, TNFA, IL8, and IL6) was observed in both ileum and colon, compared with controls. In contrast CSS induced a marked upregulation of mRNA for IL10 and mast cell chymase gene (CMA1) in the ileum and colon. Together, these data demonstrate that chronic stress in pigs results in significant alterations in intestinal barrier and nutrient transport function and neuro-immune mediator and receptor expression. PMID:28170426

  4. Sequence of molecular genetic events in colorectal tumorigenesis.

    PubMed

    Laurent-Puig, P; Blons, H; Cugnenc, P H

    1999-12-01

    Intensive screening for genetic alteration in colorectal cancer led to the identification of two types of colorectal tumours that are distinct by their carcinogenesis processes. The first group, named LOH (for loss of heterozygosity)-positive, is characterized by hyperploidy and allelic losses involving preferentially chromosome 18q and chromosome 17p. More than two-thirds of colorectal cancers belong to this group. The second group, called multiple microsatellite loci (MSI)-positive cancers, is characterized by genetic instability at microsatellite loci. Although colorectal cancer cells are characterized by specific microsatellite alterations, the same four different signalling pathways, WNT/Wingless pathway, K-ras pathway, transforming growth factor (TGF)beta pathway and p53 pathway, could be implicated in tumour progression. The WNT/Wingless pathway could be altered in two different ways according to whether the cancer cells belong to the group of LOH-positive or MSI-positive tumours. LOH-positive tumours activate the WNT/Wingless signalling pathway through an adenomatous polyposis coli (APC) mutation, whereas the MSI-positive tumours activate this pathway through a beta-catenin stabilizing mutation. Beta-catenin and APC mutations were observed as early as the adenomatous stage of colorectal neoplasia. In TGFbeta pathways LOH-positive tumours inactivated SMAD2 (similar to mother against decapentaplegic drosophilia) or SMAD4, whereas in MSI-positive tumours the TGFbeta type II receptor is frequently deleted. Alteration of these genes correlated closely with the progression of the adenoma to cancer. In the p53 pathway LOH-positive tumours showed frequent p53 mutation, whereas MSI-positive tumours demonstrated BAX (BCL-2-associated X protein)-inactivating mutation. These alterations contribute to the adenoma-carcinoma transition.

  5. Loss of the anion exchanger DRA (Slc26a3), or PAT1 (Slc26a6), alters sulfate transport by the distal ileum and overall sulfate homeostasis.

    PubMed

    Whittamore, Jonathan M; Hatch, Marguerite

    2017-09-01

    The ileum is considered the primary site of inorganic sulfate ([Formula: see text]) absorption. In the present study, we explored the contributions of the apical chloride/bicarbonate (Cl(-)/[Formula: see text]) exchangers downregulated in adenoma (DRA; Slc26a3), and putative anion transporter 1 (PAT1; Slc26a6), to the underlying transport mechanism. Transepithelial (35)[Formula: see text] and (36)Cl(-) fluxes were determined across isolated, short-circuited segments of the distal ileum from wild-type (WT), DRA-knockout (KO), and PAT1-KO mice, together with measurements of urine and plasma sulfate. The WT distal ileum supported net sulfate absorption [197.37 ± 13.61 (SE) nmol·cm(-2)·h(-1)], but neither DRA nor PAT1 directly contributed to the unidirectional mucosal-to-serosal flux ([Formula: see text]), which was sensitive to serosal (but not mucosal) DIDS, dependent on Cl(-), and regulated by cAMP. However, the absence of DRA significantly enhanced net sulfate absorption by one-third via a simultaneous rise in [Formula: see text] and a 30% reduction to the secretory serosal-to-mucosal flux ([Formula: see text]). We propose that DRA, together with PAT1, contributes to [Formula: see text] by mediating sulfate efflux across the apical membrane. Associated with increased ileal sulfate absorption in vitro, plasma sulfate was 61% greater, and urinary sulfate excretion (USO4) 2.2-fold higher, in DRA-KO mice compared with WT controls, whereas USO4 was increased 1.8-fold in PAT1-KO mice. These alterations to sulfate homeostasis could not be accounted for by any changes to renal sulfate handling suggesting that the source of this additional sulfate was intestinal. In summary, we characterized transepithelial sulfate fluxes across the mouse distal ileum demonstrating that DRA (and to a lesser extent, PAT1) secretes sulfate with significant implications for intestinal sulfate absorption and overall homeostasis.NEW & NOTEWORTHY Sulfate is an essential anion that is

  6. Nuclear transport defects and nuclear envelope alterations are associated with mutation of the Saccharomyces cerevisiae NPL4 gene.

    PubMed Central

    DeHoratius, C; Silver, P A

    1996-01-01

    To identify components involved in nuclear protein import, we used a genetic selection to isolate mutants that mislocalized a nuclear-targeted protein. We identified temperature-sensitive mutants that accumulated several different nuclear proteins in the cytoplasm when shifted to the semipermissive temperature of 30 degrees C; these were termed npl (nuclear protein localization) mutants. We now present the properties of yeast strains bearing mutations in the NPL4 gene and report the cloning of the NPL4 gene and the characterization of the Np14 protein. The npl4-1 mutant was isolated by the previously described selection scheme. The second allele, npl4-2, was identified from an independently derived collection of temperature-sensitive mutants. The npl4-1 and npl4-2 strains accumulate nuclear-targeted proteins in the cytoplasm at the nonpermissive temperature consistent with a defect in nuclear protein import. Using an in vitro nuclear import assay, we show that nuclei prepared from temperature-shifted npl4 mutant cells are unable to import nuclear-targeted proteins, even in the presence of cytosol prepared from wild-type cells. In addition, npl4-2 cells accumulate poly(A)+ RNA in the nucleus at the nonpermissive temperature, consistent with a failure to export mRNA from the nucleus. The npl4-1 and npl4-2 cells also exhibit distinct, temperature-sensitive structural defects: npl4-1 cells project extra nuclear envelope into the cytoplasm, whereas npl4-2 cells from nuclear envelope herniations that appear to be filled with poly(A)+ RNA. The NPL4 gene encodes an essential M(r) 64,000 protein that is located at the nuclear periphery and localizes in a pattern similar to nuclear pore complex proteins. Taken together, these results indicate that this gene encodes a novel nuclear pore complex or nuclear pore complex-associated component required for nuclear membrane integrity and nuclear transport. Images PMID:8930904

  7. Tumor suppressor NDRG2 inhibits glycolysis and glutaminolysis in colorectal cancer cells by repressing c-Myc expression

    PubMed Central

    Chu, Dake; Wei, Li; Li, Xia; Yang, Guodong; Liu, Xinping; Yao, Libo; Zhang, Jian; Shen, Lan

    2015-01-01

    Cancer cells use glucose and glutamine as the major sources of energy and precursor intermediates, and enhanced glycolysis and glutamimolysis are the major hallmarks of metabolic reprogramming in cancer. Oncogene activation and tumor suppressor gene inactivation alter multiple intracellular signaling pathways that affect glycolysis and glutaminolysis. N-Myc downstream regulated gene 2 (NDRG2) is a tumor suppressor gene inhibiting cancer growth, metastasis and invasion. However, the role and molecular mechanism of NDRG2 in cancer metabolism remains unclear. In this study, we discovered the role of the tumor suppressor gene NDRG2 in aerobic glycolysis and glutaminolysis of cancer cells. NDRG2 inhibited glucose consumption and lactate production, glutamine consumption and glutamate production in colorectal cancer cells. Analysis of glucose transporters and the catalytic enzymes involved in glycolysis revealed that glucose transporter 1 (GLUT1), hexokinase 2 (HK2), pyruvate kinase M2 isoform (PKM2) and lactate dehydrogenase A (LDHA) was significantly suppressed by NDRG2. Analysis of glutamine transporter and the catalytic enzymes involved in glutaminolysis revealed that glutamine transporter ASC amino-acid transporter 2 (ASCT2) and glutaminase 1 (GLS1) was also significantly suppressed by NDRG2. Transcription factor c-Myc mediated inhibition of glycolysis and glutaminolysis by NDRG2. More importantly, NDRG2 inhibited the expression of c-Myc by suppressing the expression of β-catenin, which can transcriptionally activate C-MYC gene in nucleus. In addition, the growth and proliferation of colorectal cancer cells were suppressed significantly by NDRG2 through inhibition of glycolysis and glutaminolysis. Taken together, these findings indicate that NDRG2 functions as an essential regulator in glycolysis and glutaminolysis via repression of c-Myc, and acts as a suppressor of carcinogenesis through coordinately targeting glucose and glutamine transporter, multiple catalytic

  8. Tumor suppressor NDRG2 inhibits glycolysis and glutaminolysis in colorectal cancer cells by repressing c-Myc expression.

    PubMed

    Xu, Xinyuan; Li, Jianying; Sun, Xiang; Guo, Yan; Chu, Dake; Wei, Li; Li, Xia; Yang, Guodong; Liu, Xinping; Yao, Libo; Zhang, Jian; Shen, Lan

    2015-09-22

    Cancer cells use glucose and glutamine as the major sources of energy and precursor intermediates, and enhanced glycolysis and glutamimolysis are the major hallmarks of metabolic reprogramming in cancer. Oncogene activation and tumor suppressor gene inactivation alter multiple intracellular signaling pathways that affect glycolysis and glutaminolysis. N-Myc downstream regulated gene 2 (NDRG2) is a tumor suppressor gene inhibiting cancer growth, metastasis and invasion. However, the role and molecular mechanism of NDRG2 in cancer metabolism remains unclear. In this study, we discovered the role of the tumor suppressor gene NDRG2 in aerobic glycolysis and glutaminolysis of cancer cells. NDRG2 inhibited glucose consumption and lactate production, glutamine consumption and glutamate production in colorectal cancer cells. Analysis of glucose transporters and the catalytic enzymes involved in glycolysis revealed that glucose transporter 1 (GLUT1), hexokinase 2 (HK2), pyruvate kinase M2 isoform (PKM2) and lactate dehydrogenase A (LDHA) was significantly suppressed by NDRG2. Analysis of glutamine transporter and the catalytic enzymes involved in glutaminolysis revealed that glutamine transporter ASC amino-acid transporter 2 (ASCT2) and glutaminase 1 (GLS1) was also significantly suppressed by NDRG2. Transcription factor c-Myc mediated inhibition of glycolysis and glutaminolysis by NDRG2. More importantly, NDRG2 inhibited the expression of c-Myc by suppressing the expression of β-catenin, which can transcriptionally activate C-MYC gene in nucleus. In addition, the growth and proliferation of colorectal cancer cells were suppressed significantly by NDRG2 through inhibition of glycolysis and glutaminolysis. Taken together, these findings indicate that NDRG2 functions as an essential regulator in glycolysis and glutaminolysis via repression of c-Myc, and acts as a suppressor of carcinogenesis through coordinately targeting glucose and glutamine transporter, multiple catalytic

  9. Perioperative Systemic Therapy and Surgery Versus Surgery Alone for Resectable Colorectal Peritoneal Metastases.

    ClinicalTrials.gov

    2017-05-05

    Colorectal Cancer; Colorectal Neoplasms; Colorectal Carcinoma; Colorectal Adenocarcinoma; Colorectal Cancer Metastatic; Peritoneal Carcinoma; Peritoneal Neoplasms; Peritoneal Cavity Cancer; Peritoneal Carcinomatosis; Peritoneal Metastases

  10. Ethyl acetate extract from Glycosmis parva leaf induces apoptosis and cell-cycle arrest by decreasing expression of COX-2 and altering BCL-2 family gene expression in human colorectal cancer HT-29 cells.

    PubMed

    Buranabunwong, Nattaporn; Ruangrungsi, Nijsiri; Chansriniyom, Chaisak; Limpanasithikul, Wacharee

    2015-04-01

    Glycosmis parva Craib (Rutaceae) is reported to have cytotoxic and anti-inflammatory activities by decreasing COX-2 expression. To investigate the effect of G. parva on human colorectal cancer cells expressing COX-2, HT-29 cells. HT-29 cells were treated with ethyl acetate extract from the leaves of G. parva (GPE 6.25-100 µg/ml) for 24-72 h. Cell viability was evaluated by the resuzurin reduction assay. An apoptotic study was performed using annexinV/FITC-PI staining. The cell-cycle pattern was investigated by PI staining. The expression of BCL-2 family genes was analyzed by quantitative RT-PCR and expression of cyclins and COX-2 were done by RT-PCR. GPE at 6.25-100 µg/ml reduced HT-29 cell viability with IC50 values of 69.49, 55.89, and 48.94 µg/ml at 24, 48, and 72 h, respectively. HT-29 apoptosis was induced by 18.23% at 100 µg/ml. Cells in S phase decreased by 5.22% and 13.28% at 50 and 100 µg/ml, respectively, causing G0/G1 (10.6% at 50 µg/ml) and G2/M (15.67% at 100 µg/ml) accumulation. GPE at 50 µg/ml downregulated cyclin A (11.46%), cyclin E (17.98%), BCL-2 (0.32-fold), and COX-2 (29.06%) expression with an increased BAK expression (1.79-fold). GPE reduced HT-29 cell viability, inhibited cell proliferation, induced apoptosis, and arrested the cell cycle. Underlying mechanisms may involve decreases in COX-2, cyclin A, and cyclin E expression in addition to changes in BCL-2 family gene expression. Fundamental knowledge of GPE anticancer effects found in this study could lead to future use of this compound for colorectal cancer treatment.

  11. Serrated colorectal cancer: Molecular classification, prognosis, and response to chemotherapy

    PubMed Central

    Murcia, Oscar; Juárez, Miriam; Hernández-Illán, Eva; Egoavil, Cecilia; Giner-Calabuig, Mar; Rodríguez-Soler, María; Jover, Rodrigo

    2016-01-01

    Molecular advances support the existence of an alternative pathway of colorectal carcinogenesis that is based on the hypermethylation of specific DNA regions that silences tumor suppressor genes. This alternative pathway has been called the serrated pathway due to the serrated appearance of tumors in histological analysis. New classifications for colorectal cancer (CRC) were proposed recently based on genetic profiles that show four types of molecular alterations: BRAF gene mutations, KRAS gene mutations, microsatellite instability, and hypermethylation of CpG islands. This review summarizes what is known about the serrated pathway of CRC, including CRC molecular and clinical features, prognosis, and response to chemotherapy. PMID:27053844

  12. [Nutrition and colorectal cancer].

    PubMed

    Ströhle, Alexander; Maike, Wolters; Hahn, Andreas

    2007-01-01

    Diet plays an important role in the pathogenesis of colorectal cancer. Current prospective cohort studies and metaanalysis enable a reevaluation of how food or nutrients such as fiber and fat influence cancer risk. Based on the evidence criteria of the WHO/FAD, risk reduction by a high intake of fruit is assessed as possible, while a lowered risk by a high vegetable intake is probable. Especially raw vegetables and fruits seem to exert anticancer properties. The evidence of a risk reducing effect of whole grain relating to colorectal cancer is assessed as probable whereas the evidence of an increased risk by high consumption of refined white flour products and sweets is (still) insufficient despite some evidences. There is a probable risk reducing effect of milk and dairy products. e available data on eggs and red meat indicate a possible risk increasing influence. Stronger clues for a risk increasing effect have been shown for meat products leading to an evidence assessed as probable. Owing to varied interpretations of the data on fiber, the evidence of a risk reducing effect relating to colorectal cancer is assessed as possible or insufficient. The available data on alcohol consumption indicate a possible risk increasing effect. In contrast to former evaluations, diets rich in fat seem to increase colorectal cancer risk only indirectly as part of a hypercaloric diet by advancing the obesity risk. Thus, the evidence of obesity, especially visceral obesity, as a risk of colorectal cancer is judged as convincing today. Prospective cohort studies suggest that people who get higher than average amounts of folic acid from multivitamin supplements have lower risks of colorectal cancer. The evidence for a risk reducing effect of calcium, selenium, vitamin D and vitamin E on colorectal cancer is insufficient. As primary prevention, a diet rich in vegetables, fruits, whole grain products, and legumes added by low-fat dairy products, fish, and poultry can be recommended. In

  13. Radioimmunodetection of colorectal cancer

    SciTech Connect

    Kim, E.E.; Deland, F.H.; Casper, S.; Corgan, R.L.; Primus, F.J.; Goldenberg, D.M.

    1980-03-15

    This study examines the accuracy of colorectal cancer radioimmunodetection. Twenty-seven patients with a history of histologically-confirmed colonic or rectal carcinoma received a high-titer, purified goat anti-CEA IgG labelled with /sup 131/I at a total dose of at least 1.0 ..mu..Ci. Various body views were scanned at 24 and 48 hours after administration of the radioantibody. Three additional cases were evaluated; one had a villous adenoma in the rectum and received the /sup 131/I-labeled anti-CEA IgG, while two colonic carcinoma patients received normal goat IgG labelled with /sup 131/I. All of the 7 cases with primary colorectal cancer showed true-positive tumor localization, while 20 of 25 sites of metastatic colorectal cancer detected by immune scintigraphy were corroborated by other detection measures. The sensitivity of the radioimmunodetection of colorectal cancers (primary and metastatic) was found to be 90% (true-positive rate), the putative specificity (true-negative rate) was 94%, and the apparent overall accuracy of the technique was 93%. Neither the case of a villous adenoma receiving the anti-CEA IgG nor the two cases of colonic cancer receiving normal goat IgG showed tumor radiolocalization. Very high circulating CEA titers did not appear to hinder successful tumor radiolocalization. These findings suggest that in colorectal cancers the method of CEA radioimmunodetection may be of value in preoperatively determining the location and extent of disease, in assessing possible recurrence or spread postoperatively, and in localizing the source of CEA production in patients with rising or elevated CEA titers. An ancilliary benefit could be a more tumor-specific detection test for confirming the findings of other, more conventional diagnostic measures.

  14. Genomics of Colorectal Cancer in African Americans

    PubMed Central

    Brim, Hassan; Ashktorab, Hassan

    2016-01-01

    Genome-wide studies are increasingly becoming a must, especially for complex diseases such as cancer where multiple genes and diverse molecular mechanisms are known to be involved in genes’ function alteration. In this review, we report our latest genomic and epigenomic findings in African-American colorectal cancer patients. This population suffers a higher burden of the disease and most investigators in this field are looking for the underlying genetic and epigenetic targets that might be responsible for this disparity. We here report genome-wide copy number variations, single nucleotide mutations and DNA methylation findings that might be specific to this population. PMID:27917406

  15. Lower or Standard Dose Regorafenib in Treating Patients With Refractory Metastatic Colorectal Cancer

    ClinicalTrials.gov

    2017-07-11

    Colon Adenocarcinoma; Rectal Adenocarcinoma; Stage III Colorectal Cancer; Stage IIIA Colorectal Cancer; Stage IIIB Colorectal Cancer; Stage IIIC Colorectal Cancer; Stage IV Colorectal Cancer; Stage IVA Colorectal Cancer; Stage IVB Colorectal Cancer

  16. Anacetrapib and dalcetrapib differentially alters HDL metabolism and macrophage-to-feces reverse cholesterol transport at similar levels of CETP inhibition in hamsters.

    PubMed

    Briand, François; Thieblemont, Quentin; Muzotte, Elodie; Burr, Noémie; Urbain, Isabelle; Sulpice, Thierry; Johns, Douglas G

    2014-10-05

    Cholesteryl ester transfer protein (CETP) inhibitors dalcetrapib and anacetrapib differentially alter LDL- and HDL-cholesterol levels, which might be related to the potency of each drug to inhibit CETP activity. We evaluated the effects of both drugs at similar levels of CETP inhibition on macrophage-to-feces reverse cholesterol transport (RCT) in hamsters. In normolipidemic hamsters, both anacetrapib 30 mg/kg QD and dalcetrapib 200 mg/kg BID inhibited CETP activity by ~60%. After injection of 3H-cholesteryl oleate labeled HDL, anacetrapib and dalcetrapib reduced HDL-cholesteryl esters fractional catabolic rate (FCR) by 30% and 26% (both P<0.001 vs. vehicle) respectively, but only dalcetrapib increased HDL-derived 3H-tracer fecal excretion by 30% (P<0.05 vs. vehicle). After 3H-cholesterol labeled macrophage intraperitoneal injection, anacetrapib stimulated 3H-tracer appearance in HDL, but both drugs did not promote macrophage-derived 3H-tracer fecal excretion. In dyslipidemic hamsters, both anacetrapib 1 mg/kg QD and dalcetrapib 200 mg/kg BID inhibited CETP activity by ~65% and reduced HDL-cholesteryl ester FCR by 36% (both P<0.001 vs. vehicle), but only anacetrapib increased HDL-derived 3H-tracer fecal excretion significantly by 39%. After 3H-cholesterol labeled macrophage injection, only anacetrapib 1 mg/kg QD stimulated macrophage-derived 3H-tracer appearance in HDL. These effects remained weaker than those observed with anacetrapib 60 mg/kg QD, which induced a maximal inhibition of CETP and stimulation of macrophage-derived 3H-tracer fecal excretion. In contrast, dalcetrapib 200 mg/kg BID reduced macrophage-derived 3H-tracer fecal excretion by 23% (P<0.05 vs. vehicle). In conclusion, anacetrapib and dalcetrapib differentially alter HDL metabolism and RCT in hamsters. A stronger inhibition of CETP may be required to promote macrophage-to-feces reverse cholesterol transport in dyslipidemic hamsters. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Colorectal tumors: the histology report.

    PubMed

    Lanza, Giovanni; Messerini, Luca; Gafà, Roberta; Risio, Mauro

    2011-03-01

    Epithelial colorectal tumors are common pathologic entities. Their histology report should be comprehensive of a series of pathologic parameters essential for the correct clinical management of the patients. Diagnostic histologic criteria of adenomatous, serrated, inflammatory, and hamartomatous polyps and of polyposis syndromes are discussed. In addition, the pathologic features of early and advanced colorectal cancer are described and a checklist is given. Finally, molecular prognostic and predictive factors currently employed in the treatment of colorectal cancer are discussed.

  18. Alcohol consumption and risk of colorectal cancer: the Findrink study.

    PubMed

    Toriola, Adetunji T; Kurl, Sudhir; Laukanen, Jari A; Mazengo, Charles; Kauhanen, Jussi

    2008-01-01

    We investigated the association between alcohol consumption and colorectal cancer because previous studies have yielded conflicting results. As part of the Findrink study, data from the Kuopio Ischaemic Heart Disease (KIHD) Risk Factor Study were analysed. The KIHD study is a cohort of 2,682 men from Eastern Finland with no history of cancer at baseline. The men were grouped into five groups according to their weekly alcohol intake in grams. Association between alcohol and colorectal cancer was examined using Cox proportional hazard models. There were 59 cases of colorectal cancer during an average follow up of 16.7 years. Men within the highest quintile of alcohol consumption had a median weekly alcohol intake of 198.8 g. Age and examination year adjusted risk ratio of colorectal cancer among men within the highest quintile of alcohol consumption was 4.4 (95% CI: 1.6-11.9, P-value = 0.004). After adjusting for potential confounders, such as vegetable consumption, fibre intake, smoking, family history of cancer, socio-economic status, leisure time physical activity, men with the highest amount of alcohol consumption still had a 3.5-fold (95% CI: 1.2-9.9, P-value = 0.021) increased risk of colorectal cancer. Exclusion of men diagnosed with colorectal cancer during the first 2 years of follow up from the analyses did not alter the risk increase. In conclusion, this study gives further evidence of a positive association between alcohol consumption and the risk of colorectal cancer.

  19. α(1,2)fucosylation in human colorectal carcinoma

    PubMed Central

    MUINELO-ROMAY, L.; GIL-MARTÍN, E.; FERNÁNDEZ-BRIERA, A.

    2010-01-01

    Lewisb and Lewisy (Le) antigens are known to be elevated in colorectal tumours. Alterations in the catalytic behaviour of GDP-L-fucose:β-D-galactoside α(1,2)fucosyltransferase [α(1,2)FT, EC: 2.4.1.69], the key enzyme in their synthesis, have been suggested as being responsible for these changes. In particular, an aberrant tumour-specific α(1,2)FT activity that converts Lea and Lex to Leb and Ley determinants, respectively, has been reported in colorectal cancer tissues. To clarify the catalytic function of this enzyme during colorectal tumorigenesis, we analyzed α(1,2)FT activity levels in healthy and tumour colon specimens using different acceptor substrates and determined the kinetic properties of the enzyme. To complete the study, the aberrant Lea/Lex α(1,2)fucosylation was determined in healthy and tumour colorectal tissues. A correlation analysis between the activity levels and various standard clinicopathological features, such as tumour stage, was also carried out to elucidate the role of these activities in tumour progression. The results obtained confirm the enhanced α(1,2)fucosylation in colorectal neoplastic tissues and the importance of the aberrant Lea/Lex α(1,2)FT activity in this increase. However, taking into account the high levels of Lea/Lex fucosylation observed in healthy control tissues, we must rule out the idea of a colorectal tumour-specific α(1,2)FT. On the other hand, no significant association was observed between α(1,2)FT activity levels and the clinicopathological characteristics. Overall, our results suggest that α(1,2)FT activity plays a critical role in the accumulation of Leb and Ley antigens in human colorectal carcinoma. PMID:22966309

  20. Protein restriction during gestation alters histone modifications at the glucose transporter 4 (GLUT4) promoter region and induces GLUT4 expression in skeletal muscle of female rat offspring.

    PubMed

    Zheng, Shasha; Rollet, Michelle; Pan, Yuan-Xiang

    2012-09-01

    Maternal nutrition during pregnancy is an intrauterine factor that results in alteration of the offspring genome and associates with disease risk in the offspring. We investigated the impact of a maternal low-protein (LP) diet on the expression of glucose transporter 4 (GLUT4) in offspring skeletal muscle. GLUT4 is an insulin-regulated glucose transporter involved in insulin sensitivity and carbohydrate metabolism in muscle cells. We observed sex-dependent GLUT4 mRNA expression and increased GLUT4 protein content in female pup skeletal muscle with maternal LP. Analysis of transcriptional and epigenetic regulation of increased skeletal muscle GLUT4 expression in offspring rats revealed the regulatory mechanisms involved. The protein level of myocyte enhancer factor 2A (MEF2A), which has been known as an activator of GLUT4 transcription via the ability to carry out specific binding to the GLUT4 MEF2 binding sequence, increased in female pups whose mothers were fed a LP diet. Modifications of chromatin structure, including acetylated histone H3, acetylated histone H4 and di-methylated histone H3 at lysine 4, were detected at a significantly increased level at the GLUT4 promoter region in female pup muscle following a maternal LP diet. Glycogen content was also detected as up-regulated, accompanied by increased glycogen synthase in LP female offspring muscle. These results document that maternal protein restriction during pregnancy induces GLUT4 expression in female offspring skeletal muscle but not in males, which may indicate sex-dependent adaptation of glucose metabolism to a maternal LP diet.

  1. Colorectal cancer screening in Asia.

    PubMed

    Ng, Siew C; Wong, Sunny H

    2013-01-01

    The incidence and mortality of colorectal cancer are rapidly rising in several countries in Asia. However, screening guidelines are lacking. Review of literature and local data published in peer review journals. The incidence, anatomical distribution and mortality of colorectal cancer among Asian populations are comparable to those in Western countries. Flat and depressed colonic lesions are not uncommon. Male gender, smoking, obesity, metabolic syndrome and family history are risk factors for colorectal cancer. Certain ethnic groups in Asia have increased susceptibility to colorectal cancer. Faecal occult blood test, flexible sigmoidoscopy and colonoscopy are recommended options for colorectal cancer screening in Asia. Regular screening should start at the age of 50 years. The optimal screening method in Asia remains unclear. Faecal immunochemical test has been suggested as the first choice of screening test in countries with limited resources. The role of nurse endoscopists in performing endoscopic procedures for colorectal cancer screening in Asia has not been defined. There is low public awareness and little support by health authorities for screening and prevention of this emerging disease. Screening for colorectal cancer should be a national health priority in most Asian countries. Studies on barriers to screening, education of the public and engagement of family physicians are important strategies in promoting colorectal cancer screening. With more health-care support, increased public acceptance and better access to the general population, colorectal cancer screening in Asia can be rewarding.

  2. RET is a potential tumor suppressor gene in colorectal cancer

    PubMed Central

    Luo, Yanxin; Tsuchiya, Karen D.; Park, Dong Il; Fausel, Rebecca; Kanngurn, Samornmas; Welcsh, Piri; Dzieciatkowski, Slavomir; Wang, Jianping; Grady, William M.

    2012-01-01

    Cancer arises as the consequence of mutations and epigenetic alterations that activate oncogenes and inactivate tumor suppressor genes. Through a genome-wide screen for methylated genes in colon neoplasms, we identified aberrantly methylated RET in colorectal cancer. RET, a transmembrane receptor tyrosine kinase and a receptor for the GDNF-family ligands, was one of the first oncogenes to be identified and has been shown to be an oncogene in thyroid cancer and pheochromocytoma. However, unexpectedly, we found RET is methylated in 27% of colon adenomas and in 63% of colorectal cancers, and now provide evidence that RET has tumor suppressor activity in colon cancer. The aberrant methylation of RET correlates with decreased RET expression, whereas the restoration of RET in colorectal cancer cell lines results in apoptosis. Furthermore, in support of a tumor suppressor function of RET, mutant RET has also been found in primary colorectal cancer. We now show that these mutations inactivate RET, which is consistent with RET being a tumor suppressor gene in the colon. These findings suggest that the aberrant methylation of RET and the mutational inactivation of RET promote colorectal cancer formation and that RET can serve as a tumor suppressor gene in the colon. Moreover, the increased frequency of methylated RET in colon cancers compared to adenomas suggests RET inactivation is involved in the progression of colon adenomas to cancer. PMID:22751117

  3. Differential colorectal carcinogenesis: Molecular basis and clinical relevance

    PubMed Central

    Morán, Alberto; Ortega, Paloma; de Juan, Carmen; Fernández-Marcelo, Tamara; Frías, Cristina; Sánchez-Pernaute, Andrés; Torres, Antonio José; Díaz-Rubio, Eduardo; Iniesta, Pilar; Benito, Manuel

    2010-01-01

    Colorectal cancer (CCR) is one of the most frequent cancers in developed countries. It poses a major public health problem and there is renewed interest in understanding the basic principles of the molecular biology of colorectal cancer. It has been established that sporadic CCRs can arise from at least two different carcinogenic pathways. The traditional pathway, also called the suppressor or chromosomal instability pathway, follows the Fearon and Vogelstein model and shows mutation in classical oncogenes and tumour suppressor genes, such as K-ras, adenomatous polyposis coli, deleted in colorectal cancer, or p53. Alterations in the Wnt pathway are also very common in this type of tumour. The second main colorectal carcinogenesis pathway is the mutator pathway. This pathway is present in nearly 15% of all cases of sporadic colorectal cancer. It is characterized by the presence of mutations in the microsatellite sequences caused by a defect in the DNA mismatch repair genes, mostly in hMLH1 or hMSH2. These two pathways have clear molecular differences, which will be reviewed in this article, but they also present distinct histopathological features. More strikingly, their clinical behaviours are completely different, having the “mutator” tumours a better outcome than the “suppressor” tumours. PMID:21160823

  4. p53 exon 7 mutations as a predictor of poor prognosis in patients with colorectal cancer.

    PubMed

    Iniesta, P; Vega, F J; Caldés, T; Massa, M; de Juan, C; Cerdán, F J; Sánchez, A; López, J A; Torres, A J; Balibrea, J L; Benito, M

    1998-08-14

    We have studied 61 resected colorectal adenocarcinomas in order to investigate p53 mutations as a prognostic factor for this pathology. Mutations in exons 5-9 of the p53 gene were analyzed by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique followed by sequencing. Our data indicate that p53 exon 7 mutations were prevalent in the latest stages of colorectal carcinogenesis and patients bearing this alteration had the worst prognosis. Therefore, according to our results, mutations affecting exon 7 of the p53 gene could be considered as a useful marker of biological aggressiveness for colorectal cancer.

  5. From Genotype to Functional Phenotype: Unraveling the Metabolomic Features of Colorectal Cancer

    PubMed Central

    Bathe, Oliver F.; Farshidfar, Farshad

    2014-01-01

    Much effort in recent years has been expended in defining the genomic and epigenetic alterations that characterize colorectal adenocarcinoma and its subtypes. However, little is known about the functional ramifications related to various subtypes. Metabolomics, the study of small molecule intermediates in disease, provides a snapshot of the functional phenotype of colorectal cancer. Data, thus far, have characterized some of the metabolic perturbations that accompany colorectal cancer. However, further studies will be required to identify biologically meaningful metabolic subsets, including those corresponding to specific genetic aberrations. Moreover, further studies are necessary to distinguish changes due to tumor and the host response to tumor. PMID:25055199

  6. Altered response to the selective serotonin reuptake inhibitor escitalopram in mice heterozygous for the serotonin transporter: an electrophysiological and neurochemical study.

    PubMed

    Guiard, Bruno P; Mansari, Mostafa El; Murphy, Dennis L; Blier, Pierre

    2012-04-01

    A serotonin (5-HT) transporter (5-HTT; SERT) polymorphism has been associated with depressive states and poor responses to selective serotonin reuptake inhibitors (SSRIs). Given the similar attenuation of SERT activity in SERT+/- mice and in humans with short allele(s) of SERT in its promoter region, it is conceivable that SERT+/- mice offer an adequate model to mimic the human subpopulation with respect to their altered response to SSRIs. This study investigated the effects of the most selective SSRI escitalopram, in heterozygous SERT+/- mice using a combined electrophysiological and neurochemical approach. Results indicated that administration of escitalopram for 2 d resulted in a 72% and 63% decrease in dorsal raphe 5-HT neuronal firing rate in SERT+/+ and SERT+/- mice, respectively. In contrast, administration of escitalopram for 21 d produced a gradual recovery of 5-HT neuronal firing rate to basal level in SERT+/+, but not in SERT+/- mice. In the hippocampus, microdialysis revealed that sustained administration of escitalopram produced a greater increase in extracellular 5-HT ([5-HT]ext) outflow in SERT+/- than in the wild-types with or without a washout of the SSRI. Nevertheless, the ability of microiontophoretically applied 5-HT to inhibit the firing rate of CA3 pyramidal neurons was not different between SERT+/+ and SERT+/- mice given escitalopram for 21 d. The data indicate that the poor response to SSRIs of depressive patients with short allele(s) of SERT is not attributable to a lesser increase in 5-HT transmission in the hippocampus.

  7. Epidermolysis Bullosa Simplex-Type Mutations Alter the Dynamics of the Keratin Cytoskeleton and Reveal a Contribution of Actin to the Transport of Keratin SubunitsD⃞V⃞

    PubMed Central

    Werner, Nicola Susann; Windoffer, Reinhard; Strnad, Pavel; Grund, Christine; Leube, Rudolf Eberhard; Magin, Thomas Michael

    2004-01-01

    Dominant keratin mutations cause epidermolysis bullosa simplex by transforming keratin (K) filaments into aggregates. As a first step toward understanding the properties of mutant keratins in vivo, we stably transfected epithelial cells with an enhanced yellow fluorescent protein-tagged K14R125C mutant. K14R125C became localized as aggregates in the cell periphery and incorporated into perinuclear keratin filaments. Unexpectedly, keratin aggregates were in dynamic equilibrium with soluble subunits at a half-life time of <15 min, whereas filaments were extremely static. Therefore, this dominant-negative mutation acts by altering cytoskeletal dynamics and solubility. Unlike previously postulated, the dominance of mutations is limited and strictly depends on the ratio of mutant to wild-type protein. In support, K14R125C-specific RNA interference experiments resulted in a rapid disintegration of aggregates and restored normal filaments. Most importantly, live cell inhibitor studies revealed that the granules are transported from the cell periphery inwards in an actin-, but not microtubule-based manner. The peripheral granule zone may define a region in which keratin precursors are incorporated into existing filaments. Collectively, our data have uncovered the transient nature of keratin aggregates in cells and offer a rationale for the treatment of epidermolysis bullosa simplex by using short interfering RNAs. PMID:14668478

  8. [Colorectal cancer screening].

    PubMed

    Castells, Antoni

    2013-10-01

    Colorectal cancer is the paradigm of tumoral growth that is susceptible to preventive measures, especially screening. Various screening strategies with demonstrated efficacy and efficiency are currently available, notable examples being the fecal occult blood test and endoscopic tests. In addition, new modalities have appeared in the last few years that could become viable alternatives in the near future. The present article reviews the most important presentations on colorectal screening at the annual congress of the American Gastroenterological Association held in Orlando in May 2013, with special emphasis on the medium- and long-term results of strategies using the fecal occult blood test and flexible sigmoidoscopy, as well as initial experiences with the use of new biomarkers.

  9. [Colorectal cancer screening].

    PubMed

    Castells, Antoni

    2015-09-01

    Colorectal cancer is one of malignancies showing the greatest benefit from preventive measures, especially screening or secondary prevention. Several screening strategies are available with demonstrated efficacy and efficiency. The most widely used are the faecal occult blood test in countries with population-based screening programmes, and colonoscopy in those conducting opportunistic screening. The present article reviews the most important presentations on colorectal cancer screening at the annual congress of the American Gastroenterological Association held in Washington in 2015, with special emphasis on the medium-term results of faecal occult blood testing strategies and determining factors and on strategies to reduce the development of interval cancer after colonoscopy. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  10. Biology of colorectal cancer

    PubMed Central

    Arvelo, Francisco; Sojo, Felipe; Cotte, Carlos

    2015-01-01

    Colorectal cancer is a serious health problem, a challenge for research, and a model for studying the molecular mechanisms involved in its development. According to its incidence, this pathology manifests itself in three forms: family, hereditary, and most commonly sporadic, apparently not associated with any hereditary or familial factor. For the types having inheritance patterns and a family predisposition, the tumours develop through defined stages ranging from adenomatous lesions to the manifestation of a malignant tumour. It has been established that environmental and hereditary factors contribute to the development of colorectal cancer, as indicated by the accumulation of mutations in oncogenes, genes which suppress and repair DNA, signaling the existence of various pathways through which the appearance of tumours may occur. In the case of the suppressive and mutating tracks, these are characterised by genetic disorders related to the phenotypical changes of the morphological progression sequence in the adenoma/carcinoma. Moreover, alternate pathways through mutation in BRAF and KRAS genes are associated with the progression of polyps to cancer. This review surveys the research done at the cellular and molecular level aimed at finding specific alternative therapeutic targets for fighting colorectal cancer. PMID:25932044

  11. Colorectal cancer screening.

    PubMed

    Bessa Caserras, Xavier

    2016-09-01

    In the latest meeting of the American Gastroenterological Association, several clinical studies were presented that aimed to evaluate the various colorectal cancer screening strategies, although most assessed the various aspects of faecal immunochemical testing (FIT) and colonoscopy. Data were presented from consecutive FIT-based screening rounds, confirming the importance of adherence to consecutive screening rounds, achieving a similar or superior diagnostic yield to endoscopic studies. There was confirmation of the importance of not delaying endoscopic study after a positive result. Participants with a negative FIT (score of 0) had a low risk for colorectal cancer. Several studies seemed to confirm the importance of high-quality colonoscopy in colorectal cancer screening programmes. The implementation of high-quality colonoscopies has reduced mortality from proximal lesions and reduced interval cancers in various studies. Finally, participants with a normal colonoscopy result or with a small adenoma are at low risk for developing advanced neoplasms during follow-up. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  12. Minimally invasive colorectal resection for cancer is associated with a short-lived decrease in soluble Tie-2 receptor levels, which may transiently inhibit VEGF-mediated angiogenesis (via altered blood levels of free Ang-1 and Ang-2).

    PubMed

    Shantha Kumara, H M C; Grieco, Michael J; Yan, Xiaohong; Kalady, Matthew F; DiMaggio, Vincent; Kim, Donald G; Hyman, Neil; Feingold, Daniel L; Whelan, Richard L

    2010-10-01

    Angiopoetin- (Ang-) 1 inhibits and Ang-2 promotes VEGF-mediated angiogenesis via binding to endothelial cell-bound Tie-2 receptor (Tie-2). After minimally invasive colorectal resection (MICR), Ang-1 levels decrease and Ang-2 levels increase, which may stimulate angiogenesis in wounds and residual tumor foci. Soluble Tie-2 (sTie-2) modulates the effects of free Ang-1 and Ang-2 by binding to them. This study assessed perioperative MICR plasma sTie-2 levels. Blood samples were taken preoperatively (PreOp) and on postoperative days (POD) 1 and 3 from 50 cancer and 53 benign disease MICR patients. In a subgroup, a fourth sample was taken between POD7 and POD13 and bundled as a single time point. sTie-2 levels (ng/ml) were determined via ELISA. The mean and SD were determined at each time point. The t test used for analysis. PreOp plasma sTie-2 levels were significantly higher in the benign group (27.6 ± 10.2) than in the cancer group (22.9 ± 7.9). A significant drop from PreOp occurred in sTie-2 levels in the cancer group on POD1 (20.0 ± 7.4) and POD3 (21.0 ± 6.6) and in the benign group on POD1 (24.8 ± 9.1). The benign group's POD3 and the cancer group's POD7-13 sTie-2 levels were statistically similar to the PreOp levels while the benign group's POD7-13 level was significantly higher. PreOp sTie-2 levels were significantly lower in cancer patients. MICR is associated with a significant short-lived decrease in plasma sTie-2 levels in cancer patients on POD1 and 3, which may briefly inhibit VEGF-mediated angiogenesis. The benign group's early results were similar.

  13. Aberrant methylation patterns in colorectal cancer: a meta-analysis.

    PubMed

    Durso, Danielle Fernandes; Bacalini, Maria Giulia; do Valle, Ítalo Faria; Pirazzini, Chiara; Bonafé, Massimiliano; Castellani, Gastone; Faria, Ana Maria Caetano; Franceschi, Claudio; Garagnani, Paolo; Nardini, Christine

    2017-02-21

    Colorectal cancer is among the leading causes of cancer death worldwide. Despite numerous molecular characterizations of the phenomenon, the exact dynamics of its onset and progression remain elusive. Colorectal cancer onset has been characterized by changes in DNA methylation profiles, that, owing to the stability of their patterns, are promising candidates to shed light on the molecular events laying at the base of this phenomenon.To exploit this stability and reinforce it, we conducted a meta-analysis on publicly available DNA methylation datasets generated on: normal colorectal, adenoma (ADE) and adenocarcinoma (CRC) samples using the Illumina 450k array, in the systems medicine frame, searching for tumor gene episignatures, to produce a carefully selected list of potential drivers, markers and targets of the disease. The analysis proceeds from a differential meta-analysis of the methylation profiles using an analytical pipeline recently developed by our group [1], through network reconstruction, topological and functional analyses, to finally highlight relevant epigenomic features. Our results show that genes already highlighted for their genetic or transcriptional alteration in colorectal cancer are also differentially methylated, reinforcing -regardless of the level of cellular control- their role in the complex of alterations involved in tumorigenesis.These findings were finally validated in an independent cohort from The Cancer Genome Atlas (TCGA).

  14. Cystitis increases colorectal afferent sensitivity in the mouse.

    PubMed

    Brumovsky, Pablo Rodolfo; Feng, Bin; Xu, Linjing; McCarthy, Carly Jane; Gebhart, G F

    2009-12-01

    Studies in humans and rodents suggest that colon inflammation promotes urinary bladder hypersensitivity and, conversely, that cystitis contributes to colon hypersensitivity, events referred to as cross-organ sensitization. To investigate a potential peripheral mechanism, we examined whether cystitis alters the sensitivity of pelvic nerve colorectal afferents. Male C57BL/6 mice were treated with cyclophosphamide (CYP) or saline, and the mechanosensitive properties of single afferent fibers innervating the colorectum were studied with an in vitro preparation. In addition, mechanosensitive receptive endings were exposed to an inflammatory soup (IS) to study sensitization. Urinary bladder mechanosensitive afferents were also tested. We found that baseline responses of stretch-sensitive colorectal afferents did not differ between treatment groups. Whereas IS excited a proportion of colorectal afferents CYP treatment did not alter the magnitude of this response. However, the number of stretch-sensitive fibers excited by IS was increased relative to saline-treated mice. Responses to IS were not altered by CYP treatment, but the proportion of IS-responsive fibers was increased relative to saline-treated mice. In bladder, IS application increased responses of muscular afferents to stretch, although no differences were detected between saline- and CYP-treated mice. In contrast, their chemosensitivity to IS was decreased in the CYP-treated group. Histological examination revealed no changes in colorectum and modest edema and infiltration in the urinary bladder of CYP-treated mice. In conclusion, CYP treatment increased mechanical sensitivity of colorectal muscular afferents and increased the proportion of chemosensitive colorectal afferents. These data support a peripheral contribution to cross-organ sensitization of pelvic organs.

  15. [Colorectal cancer screening with colonoscopy].

    PubMed

    Pereyra, Lisandro; Gómez, Estanislao J; Mella, José M; Cimmino, Daniel G; Boerr, Luis A

    2013-01-01

    Colorectal cancer is one of the leading causes of cancer death worldwide and also in Argentina. In the past few years colorectal cancer screening has become more popular and colonoscopy has been postulated as the gold standard. In this review we analyzed the evidence supporting this method in contrast with its complications and disadvantages.

  16. Microsatellite Instability in Colorectal Cancer

    PubMed Central

    Boland, C. Richard; Goel, Ajay

    2011-01-01

    Microsatellite instability (MSI) is a hypermutable phenotype caused by the loss of DNA mismatch repair activity. MSI is detected in about 15% of all colorectal cancers; 3% are of these are associated with Lynch syndrome and the other 12% are caused by sporadic, acquired hypermethylation of the promoter of the MLH1 gene, which occurs in tumors with the CpG island methylator phenotype. Colorectal tumors with MSI have distinctive features, including a tendency to arise in the proximal colon, lymphocytic infiltrate, and a poorly differentiated, mucinous or signet ring appearance. They have a slightly better prognosis than colorectal tumors without MSI and do not have the same response to chemotherapeutics. Discovery of MSI in colorectal tumors has increased awareness of the diversity of colorectal cancers and implications for specialized management of patients. PMID:20420947

  17. Gut flora profiling and fecal metabolite composition of colorectal cancer patients and healthy individuals.

    PubMed

    Wang, Xiaoxue; Wang, Jianping; Rao, Benqiang; Deng, Li

    2017-06-01

    Colorectal cancer is one of the most common types of cancer in the world and its morbidity and mortality rates are increasing due to alterations to human lifestyle and dietary habits. The relationship between human gut flora and colorectal cancer has attracted increasing attention. In the present study, a metabolic fingerprinting technique that combined pyrosequencing with gas chromatography-mass spectrometry was utilized to compare the differences in gut flora profiling and fecal metabolites between healthy individuals and patients with colorectal cancer. The results demonstrated that there were no significant differences in the abundance and diversity of gut flora between healthy individuals and patients with colorectal cancer (P>0.05) and the dominant bacterial phyla present in the gut of both groups included Firmicutes, Bacteroidetes and Verrucomicrobia. At the bacterial strain/genus level, significant differences were observed in the relative abundance of 18 species of bacteria (P<0.05). Analysis of fecal metabolites demonstrated that the metabolic profiles of healthy individuals and patients with colorectal cancer were distinct. The levels of short-chain fatty acid metabolites, including acetic acid, valeric acid, isobutyric acid and isovaleric acid, and of nine amino acids in patients with colorectal cancer were significantly higher than those in healthy individuals (P<0.05). However, the levels of butyrate, oleic acid, trans-oleic acid, linoleic acid, glycerol, monoacyl glycerol, myristic acid, ursodesoxycholic acid and pantothenic acid in patients with colorectal cancer were significantly lower than those in healthy individuals (P<0.05). Pearson rank correlation analysis demonstrated that there was a correlation between gut flora profiling and metabolite composition. These findings suggest that gut flora disorder results in the alteration of bacterial metabolism, which may be associated with the pathogenesis of colorectal cancer. The results of the present

  18. Practical genetics of colorectal cancer.

    PubMed

    Lynch, Henry T; Shaw, Trudy G

    2013-06-01

    Hereditary colorectal cancer (CRC) is highly heterogeneous, both genotypically and phenotypically. The most frequently occurring hereditary colorectal cancer syndrome is Lynch syndrome, accounting for approximately 3% of the total colorectal cancer burden. Polyposis syndromes, such as familial adenomatous polyposis, account for a lesser percentage. Familial colorectal cancer, defined by family history, occurs in an estimated 20% of all colorectal cancer cases. With a worldwide annual colorectal cancer incidence of over one million, and annual mortality of over 600,000, hereditary and familial forms of colorectal cancer are a major public health problem. Lynch syndrome is attributable to DNA mismatch repair germline mutations, with the MSH2, MLH1, MSH6, and PMS2 genes being implicated. The characteristics of Lynch syndrome-associated colorectal tumors, including early age of onset and predilection to the proximal colon, mandate surveillance by colonoscopy beginning by age 20 to 25 and repeated every other year through age 40 and annually thereafter. Besides colorectal cancer, Lynch syndrome also predisposes to a litany of extracolonic cancers, foremost of which is endometrial cancer, followed by cancer of the ovary, stomach, renal pelvis and ureter, small bowel, hepatobiliary tract, pancreas, glioblastoma multiforme in the Turcot's variant, and sebaceous skin tumors in the Muir-Torre variant and, more recently identified, cancers of the breast and prostate. The most common polyposis syndrome is familial adenomatous polyposis, caused by mutations in the APC gene. Affected individuals have multiple colonic adenomas and, without treatment invariably develop colorectal cancer. Colonic surveillance with polypectomy may be pursued until the appearance of multiple colonic adenomas, at which time prophylactic colectomy should be considered. Extra-intestinal manifestations include desmoid tumor, hepatoblastoma, thyroid carcinoma, and medulloblastoma. Other polyposis

  19. Alterations in microsomal electron transport, oxidative N-demethylation and azo-dye cleavage in carbon tetrachloride and dimethylnitrosamine-induced liver injury

    PubMed Central

    Smuckler, E. A.; Arrhenius, E.; Hultin, T.

    1967-01-01

    The effect of administration of carbon tetrachloride and dimethylnitrosamine in vivo on hepatic microsomal function related to drug metabolism was measured. It was found that the capacity of isolated microsomes to demethylate dimethylaniline was diminished during the first hour after carbon tetrachloride poisoning and during the second hour after dimethylnitrosamine poisoning. Thereafter the microsomes from carbon tetrachloride-poisoned livers showed a continuous decline in activity so that at 24hr. there was little residual capacity to undertake demethylation. Microsomes from dimethylnitrosamine-poisoned animals were not different from controls at 24hr. During the first 3hr. there was a transient rise in the accumulation of the N-oxide intermediate in carbon tetrachloride-poisoned livers, with a subsequent fall to below control values. In dimethylnitrosamine poisoning there was a parallel decrease in N-oxide accumulation with decreased demethylation. In the latter part of the first 24hr. the ratio of N-oxide accumulation to demethylation was increased in both instances. At 2hr. after poisoning with either compound there was no evidence of altered NADPH2-dependent neotetrazolium reduction or lipid peroxidation. NADPH2-dependent azo-dye cleavage was decreased. There was no difference in microsomal cytochrome b5 content, but there was a decrease in the amount of cytochrome P-450. This latter change was correlated with the decreased capacity for NADPH2-dependent oxidative demethylation. It is suggested that dimethylnitrosamine is associated with a defect in microsomal NADPH2-dependent electron transport at the level of cytochrome P-450. In addition to affecting cytochrome P-450, carbon tetrachloride is associated with a second severe block involving the release of formaldehyde from the N-oxide intermediate. PMID:6040018

  20. Effects of the altered activity of δ-opioid receptor on the expression of glutamate transporter type 3 induced by chronic exposure to morphine.

    PubMed

    Wu, Qiang; Xia, Shuxuan; Lin, Jing; Cao, Dexiong; Chen, Weiqiang; Liu, Ling; Fu, Yanni; Liang, Jianjun; Cao, Minghui

    2013-12-15

    Altered δ-opioid receptor (DOR) activity can affect the activity and function of excitatory amino acid transporter 3 (EAAT3), but the effects of DOR on EAAT3 expression in morphine relapse remain unknown. In this study, a C6δ cell line and SD rats in a conditioned place preference (CPP) reinstatement model were used. Here, we show that EAAT3 protein levels in C6δ cells decreased significantly after chronic exposure to morphine (10 μM) for 48 h and returned to normal 12 h after drug withdrawal. When C6δ cells were re-exposed to 5 μM morphine for 4 h, EAAT3 protein levels again decreased significantly. The selective μ opioid receptor (MOR) specific agonist DAMGO had a similar effect as morphine, and CTOP, a specific MOR blocker, reversed the declined expression of EAAT3 protein triggered by morphine exposure. The selective DOR agonist [d-pen2, 5] enkephalin (DPDPE) significantly increased EAAT3 expression in C6δ cells and even reversed the decreased EAAT3 expression caused by chronic morphine exposure. The non specific antagonist naloxone, but not the DOR inhibitor Naltrindole (NTI), reversed the decreased EAAT3 expression in C6δ cells caused by chronic morphine exposure. In vivo, EAAT3 levels in the prefrontal cortex of rats with morphine-induced CPP reinstatement significantly decreased. Naloxone completely suppressed reinstatement and reversed the decrease in EAAT3 expression induced by morphine re-exposure. In contrast, NTI only weakened CPP reinstatement and exerted no influence on EAAT3 expression. These findings suggest that DOR can affect the expression of EAAT3. However, the morphine-induced down-regulation of EAAT3 in C6δ cells and in the prefrontal cortex of rats may not be mediated by DOR.

  1. The legacy pesticide dieldrin acts as a teratogen and alters the expression of dopamine transporter and dopamine receptor 2a in zebrafish (Danio rerio) embryos.

    PubMed

    Sarty, Kathleena I; Cowie, Andrew; Martyniuk, Christopher J

    2017-04-01

    Dieldrin (DLD) is a lipophilic pesticide that shows environmental persistence. The objectives were to determine the effects of DLD on GABAergic and dopaminergic systems in developing zebrafish. Both chorionated and dechorionated embryos (~24h post-hatch) were exposed to a single concentration of DLD (0.347-3470μM) for 48h. Following exposure, a subset of larvae was placed into clean water for 6days (i.e. depuration phase). Chorionated embryos showed <15% mortality while dechorionated embryos showed higher mortality (>30%), suggesting that the chorion protected the embryos. Over a 6day depuration phase, there was a dose dependent effect observed in both the "dechorionated and chorionated embryo" treatments for larval mortality (>60%). At the end of depuration, there was no detectable change in neuro-morphological endpoints that included the ratio of notochord length to body length (%) and the ratio of head area to body area (%). However, DLD did induce cardiac edema, skeletal deformities, and tremors. GABA-related transcripts were not affected in abundance by DLD. Conversely, the relative mRNA levels of dopamine transporter (dat1) and dopamine receptor drd2a mRNA were decreased in dechorionated, but not chorionated, embryos. These data suggest that DLD can alter the expression of transcripts related to dopaminergic signaling. Lastly, GABAA receptor subunits gabrB1 and gabrB2, as well as dopamine receptors drd1 and drd2a, were inherently higher in abundance in dechorionated embryos compared to chorionated embryos. This is an important consideration when incorporating transcriptomics into embryo testing as expression levels can change with removal of the chorion prior to exposure. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. An auxin transport independent pathway is involved in phosphate stress-induced root architectural alterations in Arabidopsis. Identification of BIG as a mediator of auxin in pericycle cell activation.

    PubMed

    López-Bucio, José; Hernández-Abreu, Esmeralda; Sánchez-Calderón, Lenin; Pérez-Torres, Anahí; Rampey, Rebekah A; Bartel, Bonnie; Herrera-Estrella, Luis

    2005-02-01

    Arabidopsis (Arabidopsis thaliana) plants display a number of root developmental responses to low phosphate availability, including primary root growth inhibition, greater formation of lateral roots, and increased root hair elongation. To gain insight into the regulatory mechanisms by which phosphorus (P) availability alters postembryonic root development, we performed a mutant screen to identify genetic determinants involved in the response to P deprivation. Three low phosphate-resistant root lines (lpr1-1 to lpr1-3) were isolated because of their reduced lateral root formation in low P conditions. Genetic and molecular analyses revealed that all lpr1 mutants were allelic to BIG, which is required for normal auxin transport in Arabidopsis. Detailed characterization of lateral root primordia (LRP) development in wild-type and lpr1 mutants revealed that BIG is required for pericycle cell activation to form LRP in both high (1 mm) and low (1 microm) P conditions, but not for the low P-induced alterations in primary root growth, lateral root emergence, and root hair elongation. Exogenously supplied auxin restored normal lateral root formation in lpr1 mutants in the two P treatments. Treatment of wild-type Arabidopsis seedlings with brefeldin A, a fungal metabolite that blocks auxin transport, phenocopies the root developmental alterations observed in lpr1 mutants in both high and low P conditions, suggesting that BIG participates in vesicular targeting of auxin transporters. Taken together, our results show that auxin transport and BIG function have fundamental roles in pericycle cell activation to form LRP and promote root hair elongation. The mechanism that activates root system architectural alterations in response to P deprivation, however, seems to be independent of auxin transport and BIG.

  3. [Genetics of colorectal cancer].

    PubMed

    Balaguer, Francesc

    2013-10-01

    Up to 5% of all cases of colorectal cancer (CRC) are due to a known hereditary syndrome. These hereditary forms often require a high degree of suspicion for their diagnosis and specific and specialized management. Moreover, a diagnosis of hereditary CRC has important consequences, not only for patients-for whom highly effective preventive measures are available-, but also for their relatives, who may be carriers of the same condition. The most significant advances in the field of hereditary CRC have been produced in the diagnosis and characterization of these syndromes and in the discovery of new causative genes.

  4. Complications in colorectal surgery.

    PubMed

    Frischer, Jason S; Rymeski, Beth

    2016-12-01

    Colorectal pediatric surgery is a diverse field that encompasses many different procedures. The pullthrough for Hirschsprung disease, the posterior sagittal anorectoplasty for anorectal malformations including complex cloaca reconstructions and the ileal pouch anal anastomosis for ulcerative colitis and familial adenomatous polyposis present some of the most technically challenging procedures pediatric surgeons undertake. Many children prevail successfully following these surgical interventions, however, a small number of patients suffer from complications following these procedures. Anticipated postoperative problems are discussed along with medical and surgical strategies for managing these complications. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Screening for colorectal cancer.

    PubMed

    Mandel, Jack S

    2008-03-01

    Although there are several methods available for colon cancer screening, none is optimal. This article reviews methods for screening, including fecal occult blood tests, flexible sigmoidoscopy, colonoscopy, CT colonography, capsule endoscopy, and double contrast barium enema. A simple, inexpensive, noninvasive, and relatively sensitive screening test is needed to identify people at risk for developing advanced adenomas or colorectal cancer who would benefit from colonoscopy. It is hoped that new markers will be identified that perform better. Until then we fortunately have a variety of screening strategies that do work.

  6. What's New in Colorectal Cancer Research and Treatment?

    MedlinePlus

    ... Cancer Research? Colorectal Cancer About Colorectal Cancer What’s New in Colorectal Cancer Research? Research is always going ... ways to find colorectal cancer early by studying new types of screening tests and improving the ones ...

  7. Primary Prevention of Colorectal Cancer

    PubMed Central

    Chan, Andrew T.; Giovannucci, Edward L.

    2010-01-01

    Colorectal cancer has been strongly associated with a Western lifestyle. In the past several decades, much has been learned about the dietary, lifestyle, and medication risk factors for this malignancy. Although there is controversy about the role of specific nutritional factors, consideration of the dietary pattern as a whole appears useful for formulating recommendations. For example, several studies have shown that high intake of red and processed meats, highly refined grains and starches, and sugars is related to increased risk of colorectal cancer. Replacing these factors with poultry, fish, and plant sources as the primary source of protein; unsaturated fats as the primary source of fat; and unrefined grains, legumes and fruits as the primary source of carbohydrates is likely to lower risk of colorectal cancer. Although a role for supplements, including vitamin D, folate, and vitamin B6, remains uncertain, calcium supplementation is likely to be at least modestly beneficial. With respect to lifestyle, compelling evidence indicates that avoidance of smoking and heavy alcohol use, prevention of weight gain, and the maintenance of a reasonable level of physical activity are associated with markedly lower risks of colorectal cancer. Medications such as aspirin and non-steroidal anti-inflammatory drugs and post-menopausal hormones for women are associated with significant reductions in colorectal cancer risk, though their utility is affected by associated risks. Taken together, modifications in diet and lifestyle should substantially reduce the risk of colorectal cancer and could complement screening in reducing colorectal cancer incidence. PMID:20420944

  8. Culture-independent analysis of the gut microbiota in colorectal cancer and polyposis.

    PubMed

    Scanlan, Pauline D; Shanahan, Fergus; Clune, Yvonne; Collins, John K; O'Sullivan, Gerald C; O'Riordan, Micheal; Holmes, Elaine; Wang, Yulan; Marchesi, Julian R

    2008-03-01

    A role for the intestinal microbiota is routinely cited as a potential aetiological factor in colorectal cancer initiation and progression. As the majority of bacteria in the gut are refractory to culture we investigated this ecosystem in subjects with colorectal cancer and with adenomatous polyposis who are at high risk of developing colorectal cancer, using culture-independent methods. Twenty colorectal cancer and 20 polypectomized volunteers were chosen for this analysis. An exploration of the diversity and temporal stability of the dominant bacteria and several bacterial subgroups was undertaken using 16S rRNA gene denaturing gradient gel electrophoresis and ribosomal intergenic spacer analysis (RISA). Metabonomic analysis of the distal gut microbiota's environment was also undertaken. A significantly reduced temporal stability and increased diversity for the microbiota of subjects with colorectal cancer and polyposis was evident. A significantly increased diversity of the Clostridium leptum and C. coccoides subgroups was also noted for both disease groups. A clear division in the metabonome was observed for the colorectal cancer and polypectomized subjects compared with control volunteers. The intestinal microbiota and their metabolites are significantly altered in both colorectal cancer and polypectomized subjects compared with controls.

  9. Selumetinib and Cyclosporine in Treating Patients With Advanced Solid Tumors or Advanced or Metastatic Colorectal Cancer

    ClinicalTrials.gov

    2017-09-28

    Recurrent Colorectal Carcinoma; Solid Neoplasm; Stage IIIA Colorectal Cancer AJCC v7; Stage IIIB Colorectal Cancer AJCC v7; Stage IIIC Colorectal Cancer AJCC v7; Stage IVA Colorectal Cancer AJCC v7; Stage IVB Colorectal Cancer AJCC v7

  10. [Hereditary and familial colorectal cancer].

    PubMed

    Balaguer, Francesc

    2014-09-01

    Up to 5% of all colorectal cancer cases are caused by a known hereditary syndrome. These hereditary types often need a higher degree of clinical suspicion to be diagnosed and require specific and specialized management. In addition, diagnosing hereditary colorectal cancer has significant consequences not only for the patient, for whom there are effective preventative measures, but also for their families, who could be carriers of the condition. The most significant advances in the field of colorectal cancer have come from the diagnosis and characterization of these syndromes.

  11. [Multidisciplinary therapy of colorectal cancer].

    PubMed

    Balogh, A; Kahán, Z; Maráz, A; Mikó, T; Nagy, F; Palkó, A; Thurzó, L; Tiszlavicz, L

    2001-03-18

    A multidisciplinary program for the treatment of colorectal cancer is described. The main objective of the authors has been to define uniform up to date guidelines based on recent progress in the treatment of colorectal cancer. Preoperative diagnostic procedures are summarized which advance determination of clinical stage and prognosis. These information essentially determine care. Sequences of surgical methods, preoperative and postoperative radiotherapy and medical treatments are discussed according to tumor stages. Guidelines for surveillance following active treatment and recommendation for the screening of population at high risk for colorectal cancer are presented.

  12. Lysophosphatidylcholine acyltransferase 1 (LPCAT1) overexpression in human colorectal cancer.

    PubMed

    Mansilla, Francisco; da Costa, Kerry-Ann; Wang, Shuli; Kruhøffer, Mogens; Lewin, Tal M; Orntoft, Torben F; Coleman, Rosalind A; Birkenkamp-Demtröder, Karin

    2009-01-01

    The alteration of the choline metabolite profile is a well-established characteristic of cancer cells. In colorectal cancer (CRC), phosphatidylcholine is the most prominent phospholipid. In the present study, we report that lysophosphatidylcholine acyltransferase 1 (LPCAT1; NM_024830.3), the enzyme that converts lysophosphatidylcholine into phosphatidylcholine, was highly overexpressed in colorectal adenocarcinomas when compared to normal mucosas. Our microarray transcription profiling study showed a significant (p < 10(-8)) transcript overexpression in 168 colorectal adenocarcinomas when compared to ten normal mucosas. Immunohistochemical analysis of colon tumors with a polyclonal antibody to LPCAT1 confirmed the upregulation of the LPCAT1 protein. Overexpression of LPCAT1 in COS7 cells localized the protein to the endoplasmic reticulum and the mitochondria and increased LPCAT1 specific activity 38-fold. In cultured cells, overexpressed LPCAT1 enhanced the incorporation of [(14)C]palmitate into phosphatidylcholine. COS7 cells transfected with LPCAT1 showed no growth rate alteration, in contrast to the colon cancer cell line SW480, which significantly (p < 10(-5)) increased its growth rate by 17%. We conclude that LPCAT1 may contribute to total choline metabolite accumulation via phosphatidylcholine remodeling, thereby altering the CRC lipid profile, a characteristic of malignancy.

  13. [Colorectal cancer in spouses of colorectal cancer patients].

    PubMed

    Matsumata, T; Shikada, Y; Hasuda, S; Kishihara, F; Suehiro, T; Funahashi, S; Nagamatsu, Y; Iso, Y; Shima, I; Koga, C; Osamura, S; Ueda, M; Furuya, K; Sakino, I

    2000-06-01

    Married couples share home environments and life style for years. In the case of colorectal cancer, an association with insulin resistance was reported. We determined the presence of the insulin-resistance syndrome (IRS, 1 or more of the following: body mass index of > 25 kg/m2, diabetes, or hyperlipidemia) in 84 colorectal cancer patients, of whom 61 patients (73%) had IRS. The incidence of the distal colorectal cancer, which has been declining in the United States, was significantly higher in the IRS group than in the non-IRS group (75.4 vs 52.2%, p = 0.0400). Some mechanisms may promote the progression of mucosal lesions to invasive cancers in the distal colorectum. There were no significant differences with respect to the age (64.6 +/- 9.4 vs 64.3 +/- 11.3 yr, p = 0.8298), height (159 +/- 9 vs 157 +/- 8 cm, p = 0.1375), and body mass index (22.2 +/- 3.6 vs 22.4 +/- 2.7 kg/m2, p = 0.6364) between the patients and their spouses. In 84 couples in whom colorectal cancer develops at least in one may then not illustrate the nursery rhyme: "Jack Sprat could eat no fat, His wife could eat no lean...". The spouses had been married for an average of 38 years, and in 30 spouses who had been followed in a colorectal cancer screening, 5 developed colorectal cancer. To diminish the incidence of colorectal cancer in Japan, we might advise screening colonoscopy to the spouses of colorectal cancer patients, or déjà vu all over again?

  14. Mutations within the Autographa californica nucleopolyhedrovirus FP25K gene decrease the accumulation of ODV-E66 and alter its intranuclear transport.

    PubMed

    Braunagel, S C; Burks, J K; Rosas-Acosta, G; Harrison, R L; Ma, H; Summers, M D

    1999-10-01

    Previous reports indicate that mutations within the Autographa californica nucleopolyhedrosis virus FP25K gene (open reading frame 61) significantly reduce incorporation of enveloped nucleocapsids into viral occlusions. We report that FP25K is a nucleocapsid protein of both the budded virus (BV) and occluded virus (ODV), and we describe the effects of two FP25K mutations (480-1 [N-terminal truncation] and FP-betagal [C-terminal fusion]) on the expression and cellular localization of ODV-E66 and ODV-E25. Significantly decreased amounts of ODV-E66 are detected in cells infected with 480-1 or FP-betagal viral mutants, even though during FP-betagal infection, steady-state levels of ODV-E66 transcripts remain unchanged. While ODV-E66 is normally detected in intranuclear microvesicles and ODV envelopes by 24 h postinfection (p.i.), ODV-E66 remains cytosolic throughout infection in cells infected with 480-1 virus (up to 96 h p.i.), and its intranuclear localization is not detected until 96 h p.i. in cells infected with the FP-betagal mutant virus. The nuclear localization of ODV-E25 is not affected during infection by the FP-betagal mutant; however, its trafficking is significantly delayed during infection by the 480-1 mutant. Temporal Western blot analyses of cell lysates show that both 480-1 and FP-betagal mutant virus infections result in altered accumulation patterns of several structural proteins, including gp67, BV/ODV-E26, and the major capsid protein p39. In addition to BV/ODV-E26, ODV-E66 and gp67 may interact with FP25K, and ODV-E25 and p39 may also be components of a protein complex containing ODV-E66 and FP25K. Together, these data suggest that FP25K and its associated protein complex(es) may play an important role in the targeting and intracellular transport of viral proteins during infection.

  15. [Use of micro RNAs in the diagnosis and prognosis of colorectal cancer (CCR)].

    PubMed

    Arredondo-Valdez, Abril Reneé; Wence-Chavez, Laura; Rosales-Reynoso, Mónica Alejandra

    2016-01-01

    The aim of this review is to present a general overview about the importance of micro RNAs (miRNAs) in colorectal carcinoma. First, we focused on the mechanisms whereby the miRNAs regulate the expression of target genes, and how an altered regulation of them is associated with several types of cancer, including colorectal carcinoma. Later, examples of some miRNAs that have been associated with cancer development and how the expression patterns of specific miRNAs can be used as potential biomarkers for prognosis, diagnosis and therapeutic outcome in colorectal carcinoma are addressed. Finally, several polymorphisms presents in the miRNAs that have been associated to risk and prognosis in colorectal carcinoma are described.

  16. Identification of normal and cancerous human colorectal muscularis propria by multiphoton microscopy in different sections

    NASA Astrophysics Data System (ADS)

    Zhou, Yi; Chen, Zhifen; Kang, Deyong; li, Lianhuang; Zhuo, Shuangmu; Zhu, Xiaoqin; Guan, Guoxian; Chen, Jianxin

    2016-01-01

    Multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) as a potential diagnostic tool is attractive. MPM can effectively provide information about morphological and biochemical changes in biological tissues at the molecular level. In this paper, we attempt to identify normal and cancerous human colorectal muscularis propria by multiphoton microscopy in different sections (both in transverse and longitudinal sections). The results show that MPM can display different microstructure changes in the transverse and longitudinal sections of colorectal muscularis propria. MPM also can quantitatively describe the alteration of collagen content between normal and cancerous muscle layers. These are important pathological findings that MPM images can bring more detailed complementary information about tissue architecture and cell morphology through observing the transverse and longitudinal sections of colorectal muscularis propria. This work demonstrates that MPM can be better for identifying the microstructural characteristics of normal and cancerous human colorectal muscularis propria in different sections.

  17. Hyperaldosteronism and altered expression of an SGK1-dependent sodium transporter in ZDF rats leads to salt dependence of blood pressure.

    PubMed

    Resch, Markus; Bergler, Tobias; Fredersdorf, Sabine; Griese, Daniel P; Weil, Joachim; Kreuzer, Peter; Brunner, Sabine; Riegger, Günter A J; Luchner, Andreas; Endemann, Dierk H

    2010-10-01

    This study was designed to test whether altered aldosterone-related sodium handling leads to salt-sensitive blood pressure in diabetes and thus may exaggerate end-organ damage. Zucker diabetic fatty (ZDF) rats, a model of type 2 diabetes, and Zucker lean (ZL) rats, as euglycemic controls, were divided into groups receiving normal (0.28%) (ZDF+N, ZL+N) and high-salt (5.5%) diets (ZDF+S, ZL+S) for 10 weeks. Renal mRNA expression of serum- and glucocorticoid-inducible kinase 1 (SGK1) and sodium transporters (for example, the epithelial sodium channel-α, ENaCα) were measured by quantitative reverse transcriptase-PCR. Vascular hypertrophy (media-to-lumen ratio, M/L) in mesenteric resistance arteries was assessed using a pressurized myograph. Systolic blood pressure (SBP) was significantly higher in ZDF+S vs. ZDF+N (146 ± 2 vs. 133 ± 3 mm Hg; P<0.05), whereas there was no difference between ZL+S and ZL+N (151 ± 3 vs. 147 ± 3 mm Hg). Plasma sodium concentration was higher in ZDF+S vs. ZDF+N, whereas there was no difference between ZL+S and ZL+N. Plasma aldosterone concentration (PAC) was higher in ZDF+N as compared with ZL+N (191 ± 23 vs. 95 ± 35 pg ml(-1); P<0.05). PAC decreased to zero in ZL+S, which was not the case in ZDF+S (0 ± 0 vs. 37 ± 2 pg ml(-1)). Salt loading decreased the mRNA expression of SGK1 in euglycemic controls (ZL+S 0.58 ± 0.2 vs. ZL+N 1.05 ± 0.05; P=0.05), whereas it significantly increased SGK1 expression in diabetic rats (ZDF+S 1.75 ± 0.15 vs. ZDF+N 0.92 ± 0.07; P<0.01). ENaCα mRNA expression paralleled these changes. The M/L of mesenteric resistance arteries was not different between ZDF+N and ZL+N. High salt significantly increased the M/L in ZDF+S vs. ZDF+N, but not in ZL+S vs. ZL+N. Systolic blood pressure in this model of type 2 diabetes mellitus is salt sensitive, leading to marked vascular remodeling. The underlying pathophysiological mechanism may be inappropriately high levels of aldosterone and up

  18. Glucose turnover and recycling in colorectal carcinoma.

    PubMed

    Kokal, W A; McCulloch, A; Wright, P D; Johnston, I D

    1983-11-01

    Glucose metabolism is affected by various pathologic states including tumors. In this project, glucose turnover and recycling rates in 11 patients with colorectal carcinoma were measured using a double-labelled 3-3H and 1-14C glucose injection technique. Fasting blood glucose, lactate, pyruvate, alanine, glycerol, 3-hydroxybutyrate, acetoacetate, plasma cortisol, and plasma insulin concentrations were also measured. No patient in the study had a history of diabetes mellitus or endocrine disorders, nor any abnormal liver function tests. The findings demonstrated a significantly elevated glucose turnover rate in patients with Dukes C and D lesions in comparison to patients with Dukes B lesions. Cori recycling rates were not significantly different between Dukes B vs. Dukes C and D patients. There were no differences between Dukes B and Dukes C and D patients in any of the metabolites measured. Furthermore, there were no significant differences in glucose turnover or recycling rates as a function of pre-illness weight loss. These data suggest that, when colorectal carcinoma extends beyond the limits of the bowel wall, glucose metabolism is significantly altered.

  19. Mucosal adherent bacterial dysbiosis in patients with colorectal adenomas

    PubMed Central

    Lu, Yingying; Chen, Jing; Zheng, Junyuan; Hu, Guoyong; Wang, Jingjing; Huang, Chunlan; Lou, Lihong; Wang, Xingpeng; Zeng, Yue

    2016-01-01

    Recent reports have suggested that the gut microbiota is involved in the progression of colorectal cancer (CRC). The composition of gut microbiota in CRC precursors has not been adequately described. To characterize the structure of adherent microbiota in this disease, we conducted pyrosequencing-based analysis of 16S rRNA genes to determine the bacterial profile of normal colons (healthy controls) and colorectal adenomas (CRC precursors). Adenoma mucosal biopsy samples and adjacent normal colonic mucosa from 31 patients with adenomas and 20 healthy volunteers were profiled using the Illumina MiSeq platform. Principal coordinate analysis (PCoA) showed structural segregation between colorectal adenomatous tissue and control tissue. Alpha diversity estimations revealed higher microbiota diversity in samples from patients with adenomas. Taxonomic analysis illustrated that abundance of eight phyla (Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, Chloroflexi, Cyanobacteria, Candidate-division TM7, and Tenericutes) was significantly different. In addition, Lactococcus and Pseudomonas were enriched in preneoplastic tissue, whereas Enterococcus, Bacillus, and Solibacillus were reduced. However, both PCoA and cluster tree analyses showed similar microbiota structure between adenomatous and adjacent non-adenoma tissues. These present findings provide preliminary experimental evidence supporting that colorectal preneoplastic lesion may be the most important factor leading to alterations in bacterial community composition. PMID:27194068

  20. Overexpression of Rad51C splice variants in colorectal tumors.

    PubMed

    Kalvala, Arjun; Gao, Li; Aguila, Brittany; Reese, Tyler; Otterson, Gregory A; Villalona-Calero, Miguel A; Duan, Wenrui

    2015-04-20

    Functional alterations in Rad51C are the cause of the Fanconi anemia complementation group O (FANCO) gene disorder. We have identified novel splice variants of Rad51C mRNA in colorectal tumors and cells. The alternatively spliced transcript variants are formed either without exon-7 (variant 1), without exon 6 and 7 (variant 2) or without exon 7 and 8 (variant 3). Real time PCR analysis of nine pair-matched colorectal tumors and non-tumors showed that variant 1 was overexpressed in tumors compared to matched non-tumors. Among 38 colorectal tumor RNA samples analyzed, 18 contained variant 1, 12 contained variant 2, 14 contained variant 3, and eight expressed full length Rad51C exclusively. Bisulfite DNA sequencing showed promoter methylation of Rad51C in tumor cells. 5-azacytidine treatment of LS-174T cells caused a 14 fold increase in variant 1, a 4.8 fold increase for variant 3 and 3.4 fold for variant 2 compared to 2.5 fold increase in WT. Expression of Rad51C variants is associated with FANCD2 foci positive colorectal tumors and is associated with microsatellite stability in those tumors. Further investigation is needed to elucidate differential function of the Rad51C variants to evaluate potential effects in drug resistance and DNA repair.

  1. Get Tested for Colorectal Cancer

    MedlinePlus

    ... of fiber . Talk with your doctor about taking aspirin every day. Taking aspirin every day can lower your risk of colorectal ... 50 to 59, ask your doctor if daily aspirin is right for you . Previous section Get Tested ...

  2. [Surgery in complicated colorectal cancer].

    PubMed

    Kreisler, Esther; Biondo, Sebastiano; Martí-Ragué, Joan

    2006-07-01

    Colorectal cancer continues to have a serious social impact. A large proportion of patients are diagnosed at an advanced stage of the disease. Approximately one-third of patients with colorectal cancer will undergo emergency surgery for a complicated tumor, with a high risk of mortality and poorer long-term prognosis. The most frequent complications are obstruction and perforation, while massive hemorrhage is rare. The curative potential of surgery, whether urgent or elective, depends on how radical the resection is, among other factors. In the literature on the management of urgent colorectal disease, there are few references to the oncological criteria for resection. Uncertainly about the optimal treatment has led to wide variability in the treatment of this entity. The present article aims to provide a critical appraisal of the controversies surrounding the role of surgery and its impact on complicated colorectal cancer.

  3. Lysyl oxidase in colorectal cancer.

    PubMed

    Cox, Thomas R; Erler, Janine T

    2013-11-15

    Colorectal cancer is the third most prevalent form of cancer worldwide and fourth-leading cause of cancer-related mortality, leading to ~600,000 deaths annually, predominantly affecting the developed world. Lysyl oxidase is a secreted, extracellular matrix-modifying enzyme previously suggested to act as a tumor suppressor in colorectal cancer. However, emerging evidence has rapidly implicated lysyl oxidase in promoting metastasis of solid tumors and in particular colorectal cancer at multiple stages, affecting tumor cell proliferation, invasion, and angiogenesis. This emerging research has stimulated significant interest in lysyl oxidase as a strong candidate for developing and deploying inhibitors as functional efficacious cancer therapeutics. In this review, we discuss the rapidly expanding body of knowledge concerning lysyl oxidase in solid tumor progression, highlighting recent advancements in the field of colorectal cancer.

  4. Altered Profile of Secondary Metabolites in the Root Exudates of Arabidopsis ATP-Binding Cassette Transporter Mutants1[C][W][OA

    PubMed Central

    Badri, Dayakar V.; Loyola-Vargas, Victor M.; Broeckling, Corey D.; De-la-Peña, Clelia; Jasinski, Michal; Santelia, Diana; Martinoia, Enrico; Sumner, Lloyd W.; Banta, Lois M.; Stermitz, Frank; Vivanco, Jorge M.

    2008-01-01

    Following recent indirect evidence suggesting a role for ATP-binding cassette (ABC) transporters in root exudation of phytochemicals, we identified 25 ABC transporter genes highly expressed in the root cells most likely to be involved in secretion processes. Of these 25 genes, we also selected six full-length ABC transporters and a half-size transporter for in-depth molecular and biochemical analyses. We compared the exuded root phytochemical profiles of these seven ABC transporter mutants to those of the wild type. There were three nonpolar phytochemicals missing in various ABC transporter mutants compared to the wild type when the samples were analyzed by high-performance liquid chromatography-mass spectrometry. These data suggest that more than one ABC transporter can be involved in the secretion of a given phytochemical and that a transporter can be involved in the secretion of more than one secondary metabolite. The primary and secondary metabolites present in the root exudates of the mutants were also analyzed by gas chromatography-mass spectrometry, which allowed for the identification of groups of compounds differentially found in some of the mutants compared to the wild type. For instance, the mutant Atpdr6 secreted a lower level of organic acids and Atmrp2 secreted a higher level of amino acids as compared to the wild type. We conclude that the release of phytochemicals by roots is partially controlled by ABC transporters. PMID:18065561

  5. Tucatinib (ONT-380) and Trastuzumab for Patients With HER2-positive Metastatic Colorectal Cancer (MOUNTAINEER)

    ClinicalTrials.gov

    2017-02-13

    Colorectal Cancer; Colorectal Carcinoma; Colorectal Tumors; Neoplasms, Colorectal; HER-2 Gene Amplification; Metastatic Cancer; Metastatic Colon Cancer; Adenocarcinoma of the Colon; Adenocarcinoma of the Rectum

  6. Diabetes Mellitus and Colorectal Neoplasia

    PubMed Central

    Acevedo, Alejandro; Diaz, Yaritza; Perez, Cynthia M.; Garau, Maria; Baron, John

    2012-01-01

    Background Many studies have provided evidence for an association between obesity, physical inactivity, and western diet as risk factors for colorectal cancer (CRC). Few studies directly address the association between type 2 Diabetes Mellitus (DM) and the risk of colorectal lesions at specific anatomic locations. Methods 2,663 subjects with a previous history of adenoma(s) and removal of all current adenomas at study entry were followed for a mean time of three years across three different chemoprevention clinical trials. The primary endpoint was colorectal adenoma recurrence and number of lesions during the treatment phase; the secondary endpoints were presence of advanced colorectal neoplasia (CRN) and location of CRN. Using log linear regression, the effect of DM status on the relative risk (RR) of CRN recurrence, advanced CRN, and location of CRN was assessed. Results DM status was not significantly associated with incidence of colorectal adenomas, incidence of advanced colorectal lesions, or left-sided colorectal neoplastic lesions. Subjects with DM had a marginally increased risk of right-sided (p= 0.06) colorectal adenomas and a significant increased risk of multiple right-sided adenomas (p=0.03) in the unadjusted model; this association was not significant after adjusting for age and other potential confounders (RR=1.22, 95% CI: 0.85–1.76). Conclusion We did not observe a statistically significant increased risk in CRN recurrence for overall neoplasia, advanced neoplasia or location of neoplasia in individuals with DM compared to non-DM individuals. However, given the patterns observed in this investigation, future studies with longer follow-up time and longer DM exposure, incorporating objective measurements of type 2 DM might help elucidate the risk of CRN among individuals with DM. PMID:23560242

  7. Genes associated with metabolic syndrome predict disease-free survival in stage II colorectal cancer patients. A novel link between metabolic dysregulation and colorectal cancer.

    PubMed

    Vargas, Teodoro; Moreno-Rubio, Juan; Herranz, Jesús; Cejas, Paloma; Molina, Susana; González-Vallinas, Margarita; Ramos, Ricardo; Burgos, Emilio; Aguayo, Cristina; Custodio, Ana B; Reglero, Guillermo; Feliu, Jaime; Ramírez de Molina, Ana

    2014-12-01

    Studies have recently suggested that metabolic syndrome and its components increase the risk of colorectal cancer. Both diseases are increasing in most countries, and the genetic association between them has not been fully elucidated. The objective of this study was to assess the association between genetic risk factors of metabolic syndrome or related conditions (obesity, hyperlipidaemia, diabetes mellitus type 2) and clinical outcome in stage II colorectal cancer patients. Expression levels of several genes related to metabolic syndrome and associated alterations were analysed by real-time qPCR in two equivalent but independent sets of stage II colorectal cancer patients. Using logistic regression models and cross-validation analysis with all tumour samples, we developed a metabolic syndrome-related gene expression profile to predict clinical outcome in stage II colorectal cancer patients. The results showed that a gene expression profile constituted by genes previously related to metabolic syndrome was significantly associated with clinical outcome of stage II colorectal cancer patients. This metabolic profile was able to identify patients with a low risk and high risk of relapse. Its predictive value was validated using an independent set of stage II colorectal cancer patients. The identification of a set of genes related to metabolic syndrome that predict survival in intermediate-stage colorectal cancer patients allows delineation of a high-risk group that may benefit from adjuvant therapy and avoid the toxic and unnecessary chemotherapy in patients classified as low risk. Our results also confirm the linkage between metabolic disorder and colorectal cancer and suggest the potential for cancer prevention and/or treatment by targeting these genes. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  8. Robotics in Colorectal Surgery

    PubMed Central

    Weaver, Allison; Steele, Scott

    2016-01-01

    Over the past few decades, robotic surgery has developed from a futuristic dream to a real, widely used technology. Today, robotic platforms are used for a range of procedures and have added a new facet to the development and implementation of minimally invasive surgeries. The potential advantages are enormous, but the current progress is impeded by high costs and limited technology. However, recent advances in haptic feedback systems and single-port surgical techniques demonstrate a clear role for robotics and are likely to improve surgical outcomes. Although robotic surgeries have become the gold standard for a number of procedures, the research in colorectal surgery is not definitive and more work needs to be done to prove its safety and efficacy to both surgeons and patients. PMID:27746895

  9. Biomarkers for Colorectal Cancer

    PubMed Central

    Tanaka, Takuji; Tanaka, Mayu; Tanaka, Takahiro; Ishigamori, Rikako

    2010-01-01

    Colorectal cancer (CRC) is the third most common epithelial malignancy in the world. Since CRC develops slowly from removable precancerous lesions, detection of the lesion at an early stage by regular health examinations can reduce the incidence and mortality of this malignancy. Colonoscopy significantly improves the detection rate of CRC, but the examination is expensive and inconvenient. Therefore, we need novel biomarkers that are non-invasive to enable us to detect CRC quite early. A number of validation studies have been conducted to evaluate genetic, epigenetic or protein markers for identification in the stool and/or serum. Currently, the fecal occult blood test is the most widely used method of screening for CRC. However, advances in genomics and proteomics will lead to the discovery of novel non-invasive biomarkers. PMID:20957089

  10. Familial colorectal cancer.

    PubMed

    Lung, M S; Trainer, A H; Campbell, I; Lipton, L

    2015-05-01

    Identifying individuals with a genetic predisposition to developing familial colorectal cancer (CRC) is crucial to the management of the affected individual and their family. In order to do so, the physician requires an understanding of the different gene mutations and clinical manifestations of familial CRC. This review summarises the genetics, clinical manifestations and management of the known familial CRC syndromes, specifically Lynch syndrome, familial adenomatous polyposis, MUTYH-associated neoplasia, juvenile polyposis syndrome and Peutz-Jeghers syndrome. An individual suspected of having a familial CRC with an underlying genetic predisposition should be referred to a familial cancer centre to enable pre-test counselling and appropriate follow up. © 2015 Royal Australasian College of Physicians.

  11. Lipidome in colorectal cancer

    PubMed Central

    Zhu, Bo; Li, Yongsheng

    2016-01-01

    Colorectal cancer (CRC) is the second leading cause of cancer-related deaths. Understanding its pathophysiology is essential for developing efficient strategies to treat this disease. Lipidome, the sum of total lipids, related enzymes, receptors and signaling pathways, plays crucial roles in multiple cellular processes, such as metabolism, energy storage, proliferation and apoptosis. Dysregulation of lipid metabolism and function contributes to the development of CRC, and can be used towards the evaluation of prognosis. The strategies targeting lipidome have been applied in clinical trails and showed promising results. Here we discuss recent advances in abnormal lipid metabolism in CRC, the mechanisms by which the lipidome regulates tumorigenesis and tumor progression, and suggest potential therapeutic targets for clinical trials. PMID:26967051

  12. Robotics in Colorectal Surgery.

    PubMed

    Weaver, Allison; Steele, Scott

    2016-01-01

    Over the past few decades, robotic surgery has developed from a futuristic dream to a real, widely used technology. Today, robotic platforms are used for a range of procedures and have added a new facet to the development and implementation of minimally invasive surgeries. The potential advantages are enormous, but the current progress is impeded by high costs and limited technology. However, recent advances in haptic feedback systems and single-port surgical techniques demonstrate a clear role for robotics and are likely to improve surgical outcomes. Although robotic surgeries have become the gold standard for a number of procedures, the research in colorectal surgery is not definitive and more work needs to be done to prove its safety and efficacy to both surgeons and patients.

  13. Obesity and colorectal cancer.

    PubMed

    Bardou, Marc; Barkun, Alan N; Martel, Myriam

    2013-06-01

    Excess body weight, as defined by the body mass index (BMI), has been associated with several diseases and includes subjects who are overweight (BMI ≥ 25-29.9 kg/m(2)) or obese (BMI ≥ 30 kg/m(2)). Overweight and obesity constitute the fifth leading risk for overall mortality, accounting for at least 2.8 million adult deaths each year. In addition around 11% of colorectal cancer (CRC) cases have been attributed to overweight and obesity in Europe. Epidemiological data suggest that obesity is associated with a 30-70% increased risk of colon cancer in men, whereas the association is less consistent in women. Similar trends exist for colorectal adenoma, although the risk appears lower. Visceral fat, or abdominal obesity, seems to be of greater concern than subcutaneous fat obesity, and any 1 kg/m(2) increase in BMI confers additional risk (HR 1.03). Obesity might be associated with worse cancer outcomes, such as recurrence of the primary cancer or mortality. Several factors, including reduced sensitivity to antiangiogenic-therapeutic regimens, might explain these differences. Except for wound infection, obesity has no significant impact on surgical procedures. The underlying mechanisms linking obesity to CRC are still a matter of debate, but metabolic syndrome, insulin resistance and modifications in levels of adipocytokines seem to be of great importance. Other biological factors such as the gut microbiota or bile acids are emerging. Many questions still remain unanswered: should preventive strategies specifically target obese patients? Is the risk of cancer great enough to propose prophylactic bariatric surgery in certain patients with obesity?

  14. Early mutation bursts in colorectal tumors

    PubMed Central

    Salomon, Matthew P.; Shibata, Darryl; Curtis, Christina; Siegmund, Kimberly; Marjoram, Paul

    2017-01-01

    Tumor growth is an evolutionary process involving accumulation of mutations, copy number alterations, and cancer stem cell (CSC) division and differentiation. As direct observation of this process is impossible, inference regarding when mutations occur and how stem cells divide is difficult. However, this ancestral information is encoded within the tumor itself, in the form of intratumoral heterogeneity of the tumor cell genomes. Here we present a framework that allows simulation of these processes and estimation of mutation rates at the various stages of tumor development and CSC division patterns for single-gland sequencing data from colorectal tumors. We parameterize the mutation rate and the CSC division pattern, and successfully retrieve their posterior distributions based on DNA sequence level data. Our approach exploits Approximate Bayesian Computation (ABC), a method that is becoming widely-used for problems of ancestral inference. PMID:28257429

  15. Colorectal cancer carcinogenesis: a review of mechanisms.

    PubMed

    Tariq, Kanwal; Ghias, Kulsoom

    2016-03-01

    Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men globally. CRC arises from one or a combination of chromosomal instability, CpG island methylator phenotype, and microsatellite instability. Genetic instability is usually caused by aneuploidy and loss of heterozygosity. Mutations in the tumor suppressor or cell cycle genes may also lead to cellular transformation. Similarly, epigenetic and/or genetic alterations resulting in impaired cellular pathways, such as DNA repair mechanism, may lead to microsatellite instability and mutator phenotype. Non-coding RNAs, more importantly microRNAs and long non-coding RNAs have also been implicated at various CRC stages. Understanding the specific mechanisms of tumorigenesis and the underlying genetic and epigenetic traits is critical in comprehending the disease phenotype. This paper reviews these mechanisms along with the roles of various non-coding RNAs in CRCs.

  16. Predictive cytogenetic biomarkers for colorectal neoplasia in medium risk patients

    PubMed Central

    Ionescu, EM; Nicolaie, T; Ionescu, MA; Becheanu, G; Andrei, F; Diculescu, M; Ciocirlan, M

    2015-01-01

    Rationale: DNA damage and chromosomal alterations in peripheral lymphocytes parallels DNA mutations in tumor tissues. Objective: The aim of our study was to predict the presence of neoplastic colorectal lesions by specific biomarkers in “medium risk” individuals (age 50 to 75, with no personal or family of any colorectal neoplasia). Me