Asymmetrically differentiating cells are formed with the aid of RNA-binding proteins (RBPs), which can bind, stabilize, regulate, and transport target mRNAs. The loss of RBPs in neurons may lead to severe neurodevelopmental diseases such as the Fragile X Syndrome with the absence of the Fragile X Mental Retardation Protein (FMRP). Because the latter is ubiquitous and shares many similarities with other RBPs involved in the development of peripheral cells, we suggest that FMRP would have a role in the differentiation of all tissues where it is expressed. A MEG-01 differentiation model was, therefore, established to study the global developmental functions of FMRP. PMA induction of MEG-01 cells causes important morphological changes driven by cytoskeletal dynamics. Cytoskeleton change and colocalization analyses were performed by confocal microscopy and sucrose gradient fractionation. Total cellular protein content and de novo synthesis were also analyzed. Microtubular transport mediates the displacement of FMRP and other RBP-containing mRNP complexes towards regions of the cell in development. De novo protein synthesis decreases significantly upon differentiation and total protein content composition is altered. Because those results are comparable with those obtained in neurons, the absence of FMRP would have significant consequences in cells everywhere in the body. The latter should be further investigated to give a better understanding of the systemic implications of imbalances of FMRP and other functionally similar RBPs.
{"title":"Molecular dynamics of FMRP and other RNA-binding proteins in MEG-01 differentiation: the role of mRNP complexes in non-neuronal development.","authors":"M. McCoy, D. Poliquin-Duchesneau, François Corbin","doi":"10.1139/BCB-2015-0131","DOIUrl":"https://doi.org/10.1139/BCB-2015-0131","url":null,"abstract":"Asymmetrically differentiating cells are formed with the aid of RNA-binding proteins (RBPs), which can bind, stabilize, regulate, and transport target mRNAs. The loss of RBPs in neurons may lead to severe neurodevelopmental diseases such as the Fragile X Syndrome with the absence of the Fragile X Mental Retardation Protein (FMRP). Because the latter is ubiquitous and shares many similarities with other RBPs involved in the development of peripheral cells, we suggest that FMRP would have a role in the differentiation of all tissues where it is expressed. A MEG-01 differentiation model was, therefore, established to study the global developmental functions of FMRP. PMA induction of MEG-01 cells causes important morphological changes driven by cytoskeletal dynamics. Cytoskeleton change and colocalization analyses were performed by confocal microscopy and sucrose gradient fractionation. Total cellular protein content and de novo synthesis were also analyzed. Microtubular transport mediates the displacement of FMRP and other RBP-containing mRNP complexes towards regions of the cell in development. De novo protein synthesis decreases significantly upon differentiation and total protein content composition is altered. Because those results are comparable with those obtained in neurons, the absence of FMRP would have significant consequences in cells everywhere in the body. The latter should be further investigated to give a better understanding of the systemic implications of imbalances of FMRP and other functionally similar RBPs.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"66 1","pages":"597-608"},"PeriodicalIF":0.0,"publicationDate":"2016-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85613091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
RecQL4, one of the 5 human RecQ helicases, is a key mediator of genomic stability and its deficiency can cause premature aging phenotypes. Here, by using CRISPR/Cas and RNAi technology, we demonstrated that autophagy level was elevated in both RecQL4 knockdown and knockout cells compared with those of the control cells. Surprisingly, mitochondrial content was increased and LC3 co-localization with mitochondria was partially lost in RecQL4 knockout cells compared with the control cells, suggesting that RecQL4 deficiency impaired mitophagic processes in U2OS cells. Furthermore, we found that knockout of RecQL4 destabilized PINK1. In addition, RecQL4 knockout cells were more susceptible to apoptosis under mitochondrial stress than the control cells. In conclusion, our findings indicated a novel role of RecQL4 in the regulation of autophagy/mitophagy in U2OS cells.
{"title":"RecQL4 regulates autophagy and apoptosis in U2OS cells.","authors":"Y. Duan, Hongbo Fang","doi":"10.1139/BCB-2016-0005","DOIUrl":"https://doi.org/10.1139/BCB-2016-0005","url":null,"abstract":"RecQL4, one of the 5 human RecQ helicases, is a key mediator of genomic stability and its deficiency can cause premature aging phenotypes. Here, by using CRISPR/Cas and RNAi technology, we demonstrated that autophagy level was elevated in both RecQL4 knockdown and knockout cells compared with those of the control cells. Surprisingly, mitochondrial content was increased and LC3 co-localization with mitochondria was partially lost in RecQL4 knockout cells compared with the control cells, suggesting that RecQL4 deficiency impaired mitophagic processes in U2OS cells. Furthermore, we found that knockout of RecQL4 destabilized PINK1. In addition, RecQL4 knockout cells were more susceptible to apoptosis under mitochondrial stress than the control cells. In conclusion, our findings indicated a novel role of RecQL4 in the regulation of autophagy/mitophagy in U2OS cells.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"26 1","pages":"551-559"},"PeriodicalIF":0.0,"publicationDate":"2016-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78837478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matilda Baptist, C. Panagabko, S. Cockcroft, J. Atkinson
Phosphatidylinositol transfer proteins (PITPs) are believed to be lipid transfer proteins because of their ability to transfer either phosphatidylinositol (PI) or phosphatidylcholine (PC) between membrane compartments, in vitro. However, the detailed mechanism of this transfer process is not fully established. To further understand the transfer mechanism of PITPs we examined the interaction of PITPs with membranes using dual polarization interferometry (DPI), which measures protein binding affinity on a flat immobilized lipid surface. In addition, a fluorescence resonance energy transfer (FRET)-based assay was also employed to monitor how quickly PITPs transfer their ligands to lipid vesicles. DPI analysis revealed that PITPβ had a higher affinity to membranes compared with PITPα. Furthermore, the FRET-based transfer assay revealed that PITPβ has a higher ligand transfer rate compared with PITPα. However, both PITPα and PITPβ demonstrated a preference for highly curved membrane surfaces during ligand transfer. In other words, ligand transfer rate was higher when the accepting vesicles were highly curved.
{"title":"Ligand and membrane-binding behavior of the phosphatidylinositol transfer proteins PITPα and PITPβ.","authors":"Matilda Baptist, C. Panagabko, S. Cockcroft, J. Atkinson","doi":"10.1139/BCB-2015-0152","DOIUrl":"https://doi.org/10.1139/BCB-2015-0152","url":null,"abstract":"Phosphatidylinositol transfer proteins (PITPs) are believed to be lipid transfer proteins because of their ability to transfer either phosphatidylinositol (PI) or phosphatidylcholine (PC) between membrane compartments, in vitro. However, the detailed mechanism of this transfer process is not fully established. To further understand the transfer mechanism of PITPs we examined the interaction of PITPs with membranes using dual polarization interferometry (DPI), which measures protein binding affinity on a flat immobilized lipid surface. In addition, a fluorescence resonance energy transfer (FRET)-based assay was also employed to monitor how quickly PITPs transfer their ligands to lipid vesicles. DPI analysis revealed that PITPβ had a higher affinity to membranes compared with PITPα. Furthermore, the FRET-based transfer assay revealed that PITPβ has a higher ligand transfer rate compared with PITPα. However, both PITPα and PITPβ demonstrated a preference for highly curved membrane surfaces during ligand transfer. In other words, ligand transfer rate was higher when the accepting vesicles were highly curved.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"40 1","pages":"528-533"},"PeriodicalIF":0.0,"publicationDate":"2016-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89327344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Grimm, Janine Mett, Christoph P. Stahlmann, V. Haupenthal, Tamara Blümel, Hannah Stötzel, H. Grimm, T. Hartmann
Omega-3 polyunsaturated fatty acids (PUFAs) have been proposed to be highly beneficial in Alzheimer's disease (AD). AD pathology is closely linked to an overproduction and accumulation of amyloid-β (Aβ) peptides as extracellular senile plaques in the brain. Total Aβ levels are not only dependent on its production by proteolytic processing of the amyloid precursor protein (APP), but also on Aβ-clearance mechanisms, including Aβ-degrading enzymes. Here we show that the omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increase Aβ-degradation by affecting insulin-degrading enzyme (IDE), the major Aβ-degrading enzyme secreted into the extracellular space of neuronal and microglial cells. The identification of the molecular mechanisms revealed that EPA directly increases IDE enzyme activity and elevates gene expression of IDE. DHA also directly stimulates IDE enzyme activity and affects IDE sorting by increasing exosome release of IDE, resulting in enhanced Aβ-degradation in the extracellular milieu. Apart from the known positive effect of DHA in reducing Aβ production, EPA and DHA might ameliorate AD pathology by increasing Aβ turnover.
{"title":"Eicosapentaenoic acid and docosahexaenoic acid increase the degradation of amyloid-β by affecting insulin-degrading enzyme.","authors":"M. Grimm, Janine Mett, Christoph P. Stahlmann, V. Haupenthal, Tamara Blümel, Hannah Stötzel, H. Grimm, T. Hartmann","doi":"10.1139/BCB-2015-0149","DOIUrl":"https://doi.org/10.1139/BCB-2015-0149","url":null,"abstract":"Omega-3 polyunsaturated fatty acids (PUFAs) have been proposed to be highly beneficial in Alzheimer's disease (AD). AD pathology is closely linked to an overproduction and accumulation of amyloid-β (Aβ) peptides as extracellular senile plaques in the brain. Total Aβ levels are not only dependent on its production by proteolytic processing of the amyloid precursor protein (APP), but also on Aβ-clearance mechanisms, including Aβ-degrading enzymes. Here we show that the omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increase Aβ-degradation by affecting insulin-degrading enzyme (IDE), the major Aβ-degrading enzyme secreted into the extracellular space of neuronal and microglial cells. The identification of the molecular mechanisms revealed that EPA directly increases IDE enzyme activity and elevates gene expression of IDE. DHA also directly stimulates IDE enzyme activity and affects IDE sorting by increasing exosome release of IDE, resulting in enhanced Aβ-degradation in the extracellular milieu. Apart from the known positive effect of DHA in reducing Aβ production, EPA and DHA might ameliorate AD pathology by increasing Aβ turnover.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"16 1","pages":"534-542"},"PeriodicalIF":0.0,"publicationDate":"2016-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80919174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Yacoub, S. M. El-Hamidy, M. Mahmoud, M. Baeshen, Hussein A. Almehdar, V. Uversky, E. Redwan, O. A. Al-Maghrabi, A. Elazzazy
In this study we identified the expression patterns of β-defensin-9 in chickens from Saudi Arabia, evaluated the antimicrobial activities of synthetic chicken β-defensin-9 (sAvBD-9) against pathogenic bacteria and fungi, and investigated the mode of action of sAvBD-9 on bacterial cells. The AvBD-9 gene of Saudi chickens encodes a polypeptide of 67 amino acids, which is highly similar to the polypeptide in duck, quail, and goose (97%, 86%, and 87%, respectively) and shares a low sequence similarity with the mammalian defensins. AvBD-9 is expressed in various organs and tissues of Saudi chickens and inhibits the growth of both Gram-negative and Gram-positive bacteria, as well as showing activity against unicellular and multicellular fungi (Aspergillus flavus, A. niger, and Candida albicans). sAvBD-9 completely inhibited the growth of both Gram-positive and Gram-negative bacterial strains as well as Candida albicans. The haemolytic effects of sAvBD-9 were limited. Morphological analysis by TEM revealed that sAvBD-9 induces shortening and swelling of Staphylococcus aureus and Shigella sonni cells, opens holes and deep craters in their envelopes, and leads to the release of their cytoplasmic content. Our data shed light on the potential applications of sAvBD-9 in the pharmaceutical industry.
{"title":"Biocidal activity of chicken defensin-9 against microbial pathogens.","authors":"H. Yacoub, S. M. El-Hamidy, M. Mahmoud, M. Baeshen, Hussein A. Almehdar, V. Uversky, E. Redwan, O. A. Al-Maghrabi, A. Elazzazy","doi":"10.1139/bcb-2015-0121","DOIUrl":"https://doi.org/10.1139/bcb-2015-0121","url":null,"abstract":"In this study we identified the expression patterns of β-defensin-9 in chickens from Saudi Arabia, evaluated the antimicrobial activities of synthetic chicken β-defensin-9 (sAvBD-9) against pathogenic bacteria and fungi, and investigated the mode of action of sAvBD-9 on bacterial cells. The AvBD-9 gene of Saudi chickens encodes a polypeptide of 67 amino acids, which is highly similar to the polypeptide in duck, quail, and goose (97%, 86%, and 87%, respectively) and shares a low sequence similarity with the mammalian defensins. AvBD-9 is expressed in various organs and tissues of Saudi chickens and inhibits the growth of both Gram-negative and Gram-positive bacteria, as well as showing activity against unicellular and multicellular fungi (Aspergillus flavus, A. niger, and Candida albicans). sAvBD-9 completely inhibited the growth of both Gram-positive and Gram-negative bacterial strains as well as Candida albicans. The haemolytic effects of sAvBD-9 were limited. Morphological analysis by TEM revealed that sAvBD-9 induces shortening and swelling of Staphylococcus aureus and Shigella sonni cells, opens holes and deep craters in their envelopes, and leads to the release of their cytoplasmic content. Our data shed light on the potential applications of sAvBD-9 in the pharmaceutical industry.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"28 1","pages":"176-87"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75167650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huiqun Wang, W. Cui, Chenchen Guo, B. Chen, Mingjuan Ji
NS5B polymerase plays an important role in viral replication machinery. TMC647055 (TMC) is a novel and potent non-nucleoside inhibitor of the HCV NS5B polymerase. However, mutations that result in drug resistance to TMC have been reported. In this study, we used molecular dynamics (MD) simulations, binding free energy calculations, and free energy decomposition to investigate the drug resistance mechanism of HCV to TMC resulting from L392I, P495T, P495S, and P495L mutations in NS5B polymerase. From the calculated results we determined that the decrease in the binding affinity between TMC and NS5B(L392I) polymerase is mainly caused by the extra methyl group at the CB atom of Ile. The polarity of the side-chain of residue 495 has no distinct influence on residue 495 binding with TMC, whereas the smaller size of the side-chain of residue 495 causes a substantial decrease in the van der Walls interaction between TMC and residue 495. Moreover, the longer length of the side-chain of residue 495 has a significant effect on the electrostatic interaction between TMC and Arg-503. Finally, we performed the same calculations and detailed analysis on other 3 mutations (L392V, P495V, and P495I). The results further confirmed our conclusions. The computational results not only reveal the drug resistance mechanism between TMC647055 and NS5B polymerase, but also provide valuable information for the rational design of more potent non-nucleoside inhibitors targeting HCV NS5B polymerase.
NS5B聚合酶在病毒复制机制中起着重要作用。TMC647055 (TMC)是一种新型有效的HCV NS5B聚合酶非核苷类抑制剂。然而，已经报道了导致对TMC耐药的突变。本研究采用分子动力学(MD)模拟、结合自由能计算和自由能分解等方法，探讨了HCV对NS5B聚合酶L392I、P495T、P495S和P495L突变引起的TMC的耐药机制。计算结果表明，TMC与NS5B(L392I)聚合酶结合亲和力的降低主要是由于Ile的CB原子上多了一个甲基。残基495侧链的极性对残基495与TMC的结合没有明显影响，而残基495侧链的尺寸越小，TMC与残基495之间的van der Walls相互作用就越弱。此外，残基495侧链的长度对TMC与Arg-503之间的静电相互作用有显著影响。最后，我们对其他3个突变(L392V、P495V和P495I)进行了相同的计算和详细分析。结果进一步证实了我们的结论。计算结果不仅揭示了TMC647055与NS5B聚合酶之间的耐药机制，也为合理设计更有效的靶向HCV NS5B聚合酶的非核苷类抑制剂提供了有价值的信息。
{"title":"Molecular modeling study on the drug resistance mechanism of NS5B polymerase to TMC647055.","authors":"Huiqun Wang, W. Cui, Chenchen Guo, B. Chen, Mingjuan Ji","doi":"10.1139/bcb-2015-0109","DOIUrl":"https://doi.org/10.1139/bcb-2015-0109","url":null,"abstract":"NS5B polymerase plays an important role in viral replication machinery. TMC647055 (TMC) is a novel and potent non-nucleoside inhibitor of the HCV NS5B polymerase. However, mutations that result in drug resistance to TMC have been reported. In this study, we used molecular dynamics (MD) simulations, binding free energy calculations, and free energy decomposition to investigate the drug resistance mechanism of HCV to TMC resulting from L392I, P495T, P495S, and P495L mutations in NS5B polymerase. From the calculated results we determined that the decrease in the binding affinity between TMC and NS5B(L392I) polymerase is mainly caused by the extra methyl group at the CB atom of Ile. The polarity of the side-chain of residue 495 has no distinct influence on residue 495 binding with TMC, whereas the smaller size of the side-chain of residue 495 causes a substantial decrease in the van der Walls interaction between TMC and residue 495. Moreover, the longer length of the side-chain of residue 495 has a significant effect on the electrostatic interaction between TMC and Arg-503. Finally, we performed the same calculations and detailed analysis on other 3 mutations (L392V, P495V, and P495I). The results further confirmed our conclusions. The computational results not only reveal the drug resistance mechanism between TMC647055 and NS5B polymerase, but also provide valuable information for the rational design of more potent non-nucleoside inhibitors targeting HCV NS5B polymerase.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"436 1","pages":"147-58"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83653867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sulfide:quinone oxidoreductase (SQR) is a peripheral membrane enzyme that catalyzes the oxidation of sulfide and the reduction of ubiquinone. Ubiquinone binds to a conserved hydrophobic domain and shuttles electrons from a noncovalent flavin adenine dinucleotide cofactor to the membrane-bound quinone pool. Utilizing the structure of decylubiquinone bound to Acidithiobacillus ferrooxidans SQR, we combined site-directed mutagenesis and kinetic approaches to analyze quinone binding. SQR can reduce both benzoquinones and naphthoquinones. The alkyl side-chain of ubiquinone derivatives enhances binding to SQR but limits the enzyme turnover. Pentachlorophenol and 2-n-heptyl-4-hydroxyquinoline-N-oxide are potent inhibitors of SQR with apparent inhibition constants (Ki) of 0.46 μmol·L(-1) and 0.58 μmol·L(-1), respectively. The highly conserved amino acids surrounding the quinone binding site play an important role in quinone reduction. The phenyl side-chains of Phe357 and Phe391 sandwich the benzoquinone head group and are critical for quinone binding. Importantly, conserved amino acids that define the ubiquinone-binding site also play an important role in sulfide oxidation/flavin reduction.
{"title":"The quinone-binding site of Acidithiobacillus ferrooxidans sulfide: quinone oxidoreductase controls both sulfide oxidation and quinone reduction.","authors":"Yanfei Zhang, A. Qadri, J. Weiner","doi":"10.1139/bcb-2015-0097","DOIUrl":"https://doi.org/10.1139/bcb-2015-0097","url":null,"abstract":"Sulfide:quinone oxidoreductase (SQR) is a peripheral membrane enzyme that catalyzes the oxidation of sulfide and the reduction of ubiquinone. Ubiquinone binds to a conserved hydrophobic domain and shuttles electrons from a noncovalent flavin adenine dinucleotide cofactor to the membrane-bound quinone pool. Utilizing the structure of decylubiquinone bound to Acidithiobacillus ferrooxidans SQR, we combined site-directed mutagenesis and kinetic approaches to analyze quinone binding. SQR can reduce both benzoquinones and naphthoquinones. The alkyl side-chain of ubiquinone derivatives enhances binding to SQR but limits the enzyme turnover. Pentachlorophenol and 2-n-heptyl-4-hydroxyquinoline-N-oxide are potent inhibitors of SQR with apparent inhibition constants (Ki) of 0.46 μmol·L(-1) and 0.58 μmol·L(-1), respectively. The highly conserved amino acids surrounding the quinone binding site play an important role in quinone reduction. The phenyl side-chains of Phe357 and Phe391 sandwich the benzoquinone head group and are critical for quinone binding. Importantly, conserved amino acids that define the ubiquinone-binding site also play an important role in sulfide oxidation/flavin reduction.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"18 1","pages":"159-66"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81706296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herpetofauna (amphibians and reptiles) and fish represent important sentinel and indicator species for environmental and ecosystem health. It is widely accepted that the epigenome plays an important role in gene expression regulation. Environmental stimuli, including temperature and pollutants, influence gene activity, and there is growing evidence demonstrating that an important mechanism is through modulation of the epigenome. This has been primarily studied in human and mammalian models; relatively little is known about the impact of environmental conditions or pollutants on herpetofauna or fish epigenomes and the regulatory consequences of these changes on gene expression. Herein we review recent studies that have begun to address this deficiency, which have mainly focused on limited specific epigenetic marks and individual genes or large-scale global changes in DNA methylation, owing to the comparative ease of measurement. Greater understanding of the epigenetic influences of these environmental factors will depend on increased availability of relevant species-specific genomic sequence information to facilitate chromatin immunoprecipitation and DNA methylation experiments.
{"title":"Environmental influences on the epigenomes of herpetofauna and fish.","authors":"S. Hammond, Christopher J. Nelson, C. Helbing","doi":"10.1139/bcb-2015-0111","DOIUrl":"https://doi.org/10.1139/bcb-2015-0111","url":null,"abstract":"Herpetofauna (amphibians and reptiles) and fish represent important sentinel and indicator species for environmental and ecosystem health. It is widely accepted that the epigenome plays an important role in gene expression regulation. Environmental stimuli, including temperature and pollutants, influence gene activity, and there is growing evidence demonstrating that an important mechanism is through modulation of the epigenome. This has been primarily studied in human and mammalian models; relatively little is known about the impact of environmental conditions or pollutants on herpetofauna or fish epigenomes and the regulatory consequences of these changes on gene expression. Herein we review recent studies that have begun to address this deficiency, which have mainly focused on limited specific epigenetic marks and individual genes or large-scale global changes in DNA methylation, owing to the comparative ease of measurement. Greater understanding of the epigenetic influences of these environmental factors will depend on increased availability of relevant species-specific genomic sequence information to facilitate chromatin immunoprecipitation and DNA methylation experiments.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"5 1","pages":"95-100"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86725184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Frycz, D. Murawa, M. Borejsza-Wysocki, M. Wichtowski, A. Spychała, R. Marciniak, P. Murawa, M. Drews, P. Jagodziński
Steroid hormones have been shown to play a role in gastric carcinogenesis. Large amounts of steroid hormones are locally produced in the peripheral tissues of both genders. Type 5 of 17β-hydroxysteroid dehydrogenase, encoded by the AKR1C3 gene, plays a pivotal role in both androgen and estrogen metabolism, and its expression was found to be deregulated in different cancers. In this study we measured AKR1C3 transcript and protein levels in nontumoral and primary tumoral gastric tissues, and evaluated their association with some clinicopathological features of gastric cancer (GC). We found decreased levels of AKR1C3 transcript (p < 0.0001) and protein (p = 0.0021) in GC tissues compared with the adjacent, apparently histopathologically normal, mucosa. Lower levels of AKR1C3 transcript were observed in diffuse and intestinal types of GC, whereas AKR1C3 protein levels were decreased in tumors with multisite localization, in diffuse histological type, T3, T4, and G3 grades. We also determined the effect of the histone deacetylase inhibitor sodium butyrate (NaBu) on AKR1C3 expression in EPG 85-257 and HGC-27 GC cell lines. We found that NaBu elevates the levels of both AKR1C3 transcript and protein in the cell lines we investigated. Together, our results suggest that decreased expression of AKR1C3 may be involved in development of GC and can be restored by NaBu.
{"title":"Transcript level of AKR1C3 is down-regulated in gastric cancer.","authors":"B. Frycz, D. Murawa, M. Borejsza-Wysocki, M. Wichtowski, A. Spychała, R. Marciniak, P. Murawa, M. Drews, P. Jagodziński","doi":"10.1139/bcb-2015-0096","DOIUrl":"https://doi.org/10.1139/bcb-2015-0096","url":null,"abstract":"Steroid hormones have been shown to play a role in gastric carcinogenesis. Large amounts of steroid hormones are locally produced in the peripheral tissues of both genders. Type 5 of 17β-hydroxysteroid dehydrogenase, encoded by the AKR1C3 gene, plays a pivotal role in both androgen and estrogen metabolism, and its expression was found to be deregulated in different cancers. In this study we measured AKR1C3 transcript and protein levels in nontumoral and primary tumoral gastric tissues, and evaluated their association with some clinicopathological features of gastric cancer (GC). We found decreased levels of AKR1C3 transcript (p < 0.0001) and protein (p = 0.0021) in GC tissues compared with the adjacent, apparently histopathologically normal, mucosa. Lower levels of AKR1C3 transcript were observed in diffuse and intestinal types of GC, whereas AKR1C3 protein levels were decreased in tumors with multisite localization, in diffuse histological type, T3, T4, and G3 grades. We also determined the effect of the histone deacetylase inhibitor sodium butyrate (NaBu) on AKR1C3 expression in EPG 85-257 and HGC-27 GC cell lines. We found that NaBu elevates the levels of both AKR1C3 transcript and protein in the cell lines we investigated. Together, our results suggest that decreased expression of AKR1C3 may be involved in development of GC and can be restored by NaBu.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"17 1","pages":"138-46"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87330484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Górecka, M. Synak, Z. Brzezińska, J. Dąbrowski, E. Żernicka
We studied whether short-term administration of triiodothyronine (T3) for the last 3 days of endurance training would influence the rate of uptake of palmitic acid (PA) as well as metabolism in rat soleus muscle, in vitro. Training per se did not affect the rate of PA uptake by the soleus; however, an excess of T3 increased the rate of this process at 1.5 mmol/L PA, as well as the rate that at which PA was incorporated into intramuscular triacylglycerols (TG). The rate of TG synthesis in trained euthyroid rats was reduced after exercise (1.5 mmol/L PA). The rate of PA oxidation in all of the trained rats immediately after exercise was enhanced by comparison with the sedentary values. Hyperthyroidism additionally increased the rate of this process at 1.5 mmol/L PA. After a recovery period, the rate of PA oxidation returned to the control values in both the euthyroid and the hyperthyroid groups. Examination of the high-energy phosphate levels indicated that elevated PA oxidation after exercise-training in euthyroid rats was associated with stable ATP levels and increased ADP and AMP levels, thus reducing energy cellular potential (ECP). In the hyperthyroid rats, levels of ADP and AMP were increased in the sedentary as well as the exercise-trained rats. ECP levels were high as a result of high levels of ATP and decreased levels of ADP and AMP in hyperthyroid rats after the recovery period. In conclusion, short-term hyperthyroidism accelerates PA utilization in well-trained soleus muscle.
{"title":"Effect of triiodothyronine (T3) excess on fatty acid metabolism in the soleus muscle from endurance-trained rats.","authors":"M. Górecka, M. Synak, Z. Brzezińska, J. Dąbrowski, E. Żernicka","doi":"10.1139/bcb-2015-0051","DOIUrl":"https://doi.org/10.1139/bcb-2015-0051","url":null,"abstract":"We studied whether short-term administration of triiodothyronine (T3) for the last 3 days of endurance training would influence the rate of uptake of palmitic acid (PA) as well as metabolism in rat soleus muscle, in vitro. Training per se did not affect the rate of PA uptake by the soleus; however, an excess of T3 increased the rate of this process at 1.5 mmol/L PA, as well as the rate that at which PA was incorporated into intramuscular triacylglycerols (TG). The rate of TG synthesis in trained euthyroid rats was reduced after exercise (1.5 mmol/L PA). The rate of PA oxidation in all of the trained rats immediately after exercise was enhanced by comparison with the sedentary values. Hyperthyroidism additionally increased the rate of this process at 1.5 mmol/L PA. After a recovery period, the rate of PA oxidation returned to the control values in both the euthyroid and the hyperthyroid groups. Examination of the high-energy phosphate levels indicated that elevated PA oxidation after exercise-training in euthyroid rats was associated with stable ATP levels and increased ADP and AMP levels, thus reducing energy cellular potential (ECP). In the hyperthyroid rats, levels of ADP and AMP were increased in the sedentary as well as the exercise-trained rats. ECP levels were high as a result of high levels of ATP and decreased levels of ADP and AMP in hyperthyroid rats after the recovery period. In conclusion, short-term hyperthyroidism accelerates PA utilization in well-trained soleus muscle.","PeriodicalId":9524,"journal":{"name":"Canadian journal of biochemistry and cell biology = Revue canadienne de biochimie et biologie cellulaire","volume":"105 1","pages":"101-8"},"PeriodicalIF":0.0,"publicationDate":"2016-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74586585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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