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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Caracteriza??o das subunidades das emiss?es sonoras de Megaptera novaeangliae (Borowski, 1781) na costa do Brasil / Characterization of the subunits of the vocalizations of Megaptera novaeangliae (Borowski, 1781) on coast of Brazil

Moreira, Sergio Carvalho 24 February 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-10-17T15:10:01Z No. of bitstreams: 1 2016 - Sergio Carvalho Moreira.pdf: 18299878 bytes, checksum: 0755537fc7d05720dfc365f593b70620 (MD5) / Made available in DSpace on 2016-10-17T15:10:01Z (GMT). No. of bitstreams: 1 2016 - Sergio Carvalho Moreira.pdf: 18299878 bytes, checksum: 0755537fc7d05720dfc365f593b70620 (MD5) Previous issue date: 2016-02-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / This study addressed the segmentation of the song of humpback whales based on the definition of the subunits. The humpback whale voalizations were identified and characterized in order to structurate the first data bank of sounds of marine mammals of the Southwestern Atlantic. It was noted the importance of these subunits because they have a degree of small variation, assisting in the identification of the species for the Autonomic Passive Acoustic Monitoring System (MAPA). Records of vocalizations of whales were conducted by the Humpback Whale Institute team (IBJ), between 2006 and 2013, in the region of Abrolhos, Bahia State, Brazil. They held seven readings of the subunits through the Raven 1.4 software, by evaluating: (1) High frequency (Hz); (2) Average power (dB); (3) Energy (dB); (4) Center frequency (Hz); (5) Maximum frequency (Hz); (6) Delta Time (s); and (7) Delta frequency (Hz). There were calculated the average, standard deviation, minimum and maximum values. Multivariate analysis of variance with post-hoc test values were performed where p>0.05 did not represent a significant change in the years. In the years 2006, 2007, 2009 and 2011 there was satisfactory quality to perform the analyzes, which corresponded to 14% of total recordings in 4:06:54 hours. The records analyzed were purchased in the months of highest occurrence of humpback. 862 subunits were identified and analyzed. The identified subunits were A, B and C. The subunit A: n= 156(18%), previously found in a feeding area in the northeast of Iceland (2011), Alaska (2012) and in the region of Abrolhos in all years studied. The B subunit: n= 205(24%), occurring in feeding areas of Iceland (2000) and Alaska (2012) and the breeding area in Hawaii (1991). In Abrolhos region they were recorded in all years studied. The C subunit: 501(51%) was previously recorded in the breeding areas of Madagascar (2009), Hawaii (1989 and 1991), Mexico (2006), Australia (2009) and New Caledonia (2010) and in the feeding area Antarctica (2010). Some subunits showed no significant differences in some of the studied years. The subunits are preserved over the years especially in following parameters: high frequency, center frequency, maximum frequency, delta time and the delta frequency. The parameter delta time has also shown more uniform average and standard deviation, indicating that this should be used as a differentiating character in the analysis of humpback sound emissions. The C subunit had a wide geographic distribution, mainly in the Southern Hemisphere. Comparison of subunits found in the literature shows that they are suitable bioacustic markers for humpback in the usage of MAPA methodology. The data obtained in this study will be used to start the first sound database for marine mammals in the South Atlantic, called SONOTECA, in partnership with the SISMMAM (Marine Mammals Sound and Monitoring Integrated System)/IBAMA. / Neste estudo foi abordada a segmenta??o da can??o de baleias jubarte com base na defini??o das subunidades. As emiss?es sonoras das jubarte foram identificadas e caracterizadas de modo a estruturar o primeiro banco de dados de sons de mam?feros marinhos do Atl?ntico Sul Ocidental. Constatou-se a import?ncia dessas subunidades por apresentarem um grau de varia??o pequeno, ajudando na identifica??o da esp?cie em sistemas de Monitoramento Ac?stico Passivo Aut?nomo (MAPA). Os registros das vocaliza??es das baleias foram realizados pela equipe do Instituto Baleia Jubarte (IBJ) de 2006 a 2013, na regi?o de Abrolhos, Bahia, Brasil. Foram realizadas sete leituras das subunidades atrav?s do software Raven 1.4, avaliando-se: (1) Alta da frequ?ncia (Hz); (2) M?dia da pot?ncia (dB); (3) Energia (dB); (4) Frequ?ncia central (Hz); (5) Frequ?ncia m?xima (Hz); (6) Delta do tempo (s); e (7) Delta da frequ?ncia (Hz). Foram calculados a m?dia, o desvio padr?o, o valor m?nimo, e o valor m?ximo. Realizadas an?lises multivariadas das vari?ncias com o valores do teste Post Hoc onde p>0,05 n?o representa varia??o significativa ao ano. Nos anos de 2006, 2007, 2009 e 2011 houve qualidade satisfat?ria para realizar as an?lises, o que correspondeu a 14% do total das grava??es, com 4:06:54h de grava??es. Os registros analisados foram adquiridos nos meses de maior ocorr?ncia de jubarte. 862 subunidades foram identificadas e analisadas. As subunidades identificadas foram A, B e C. A subunidade A (n = 156; 18%), anteriormente encontrada em uma ?rea de alimenta??o no nordeste da Isl?ndia (2011), no Alasca (2012) e na regi?o de Abrolhos, em todos anos estudados. A subunidade B (n = 205; 24%), com ocorr?ncia em ?reas de alimenta??o da Isl?ndia (2000) e no Alasca (2012) e na ?rea de reprodu??o no Hava? (1991) e na regi?o de Abrolhos foram registradas em todos anos pesquisados. A subunidade C (n = 501; 51%) foi anteriormente registrada nas ?reas de reprodu??o de Madagascar (2009), Hava? (1989 e 1991), M?xico (2006), Austr?lia (2009) e Nova Caled?nia (2010) e na ?rea de alimenta??o da Ant?rtica (2010). Algumas subunidades n?o apresentaram diferen?as significativas em alguns anos estudados. As subunidades s?o preservadas ao longo dos anos principalmente nos par?metros alta frequ?ncia, frequ?ncia central, frequ?ncia m?xima, delta de tempo e delta da frequ?ncia. O par?metro delta do tempo demostrou tamb?m a sua m?dia e desvio padr?o mais uniforme, indicando que este deve ser usado como car?ter diferenciador nas an?lises de emiss?es sonoras de jubarte. A subunidade C apresentou uma grande distribui??o geogr?fica principalmente no Hemisf?rio Sul. A compara??o das subunidades encontradas com as registrads na literatura demostra que elas s?o adequados marcadores bioac?sticos para a jubarte no uso de metodologia do MAPA. Os dados obtidos no presente estudo ser?o usados para iniciar o primeiro banco de dados de sons para mam?feros aqu?ticos no Atl?ntico Sul, denominado SONOTECA, em parceria com o SISISMMAM (Sistema Integrado de Som e Monitoramento de Mam?feros Marinhos) /IBAMA.
52

30S Ribosomal Subunit Assembly is a Target for Inhibition by Aminoglycoside Antibiotics in <em>Escherichia coli</em>.

Mehta, Roopal Manoj 04 May 2002 (has links)
Antibacterial agents specific for the 50S ribosomal subunit not only inhibit translation but also prevent assembly of that subunit. I examined the 30S ribosomal subunit in growing Escherichia coli cells to see if antibiotics specific for that subunit also had a second inhibitory effect. I used the aminoglycoside antibiotics paromomycin and neomycin, which bind specifically to the 30S ribosomal subunit. Both antibiotics inhibited the growth rate, viable cell number, and protein synthesis. I used a 3H-uridine pulse and chase assay to examine the kinetics of ribosome subunit assembly in the presence and absence of each antibiotic. Analysis revealed a concentration dependent inhibition of 30S subunit formation in the presence of each antibiotic. Sucrose gradient profiles of cell lysates showed the accumulation of an intermediate 21S translational particle. Taken together this data gives the first demonstration that 30S ribosomal subunit inhibitors can also prevent assembly of the small subunit.
53

Subunit Interactions in the Inducible Arginine Decarboxylase from Escherichia Coli B

Depusoy, Catalina N. 01 May 1983 (has links)
The nature of the subunit interactions in the inducible arginine decarboxylase from Escherichia coli B is of considerable interest because of the observed differences in the catalytic activities of the dimer and the decamer; the decamer is active and the dimer is inactive. To study these interactions, inactive dimers were prepared by sodium borohydride reduction of the E-amino--pyridoxal-P Schiff base. Hybrid decamers were then prepared from varying molar ratios of native and reduced dimers. The hybrid decamers were indistinguishable from native decamers as observed in the analytical ultracentrifuge and on acrylamide gel electrophoresis. Kinetic studies indicated that true hybrids were formed rather than mixtures of all-native and all-reduced decamers. Results obtained with the decamers containing 1, 2, 3, or 4 parts in 5 of reduced enzyme showed no significant changes in Km values from the native decamer. However, the Vm values for these hybrids are greater than predicted from the mole fraction of active dimers. For example, the hybrid containing 20% reduced enzyme approaches the Vm of the native decamer. These observations suggest that, in the intact molecule, two active sites cooperate catalytically but only one is catalytically active.
54

Structure and function of AMPK: subunit interactions of the AMPK heterotrimeric complex

Iseli, Tristan J. Unknown Date (has links) (PDF)
AMP-activated protein kinase (AMPK) is an important metabolic stress-sensing protein kinase responsible for regulating metabolism in response to changing energy demand and nutrient supply. Mammalian AMPK is a stable aß? heterotrimer comprising a catalytic a subunit and two non-catalytic subunits, ß and ?. The ß subunit targets AMPK to membranes via an N-terminal myristoyl group and to glycogen via a mid-molecule glycogen-binding domain. Here I show that the conserved C-terminal 85-residue sequence of the ß subunit, ß1(186-270), is sufficient to form an active AMP-dependent heterotrimer a1ß1(186-270)?1, whereas the 25-residue ß1 C-terminal (246-270) sequence is sufficient to bind ?1, ?2, or ?3 but not the a subunit. Within this sequence (246-270), two residues were essential for ß? association based on Ala scanning mutagenesis. / Substitution of ß1 Tyr-267 for Ala precludes ß? but not aß association suggesting independent binding requirements. Substitution of Tyr-267 for Phe or His but not Ala or Ser can rescue ß? binding. Substitution of Thr-263 for Ala also resulted in decreased ß? but not aß association. Truncation of the a subunit reveals that ß1 binding requires the a1(313-473) sequence while the remainder of the a C-terminus is required for ? binding. The conserved C-terminal 85-residue sequence of the ß subunit (90% between ß1 and ß2) is the primary a? binding sequence responsible for the formation of the AMPK aß? heterotrimer. The ? subunits contain four repeat CBS sequences with variable N-terminal extensions and the ?1 isoform is N-terminally acetylated. The ?2 subunit can be multiply phosphorylated by protein kinase C (PKC) in vitro, with Ser-32 identified as a minor site. A detailed understanding of the structure and regulation of AMPK will enable rational drug design for treatment of such linked diseases as obesity, insulin resistance and type 2 diabetes.
55

Relationship between Na+/K+ -ATPase activity and α-subunit gene expression during the smoltification in Atlantic salmon (Salmo salar)

Bergqvist, Jonas January 2008 (has links)
<p>During the smoltification the Atlantic salmon (Salmo salar) develop different adaptations to survive in oceanic environment. One of the most important adaptations is the ability to excrete the surplus of salt through the gills. The excretion is controlled by an enzyme called Na+/K+-ATPase which is produced in an α-subunit by two gene isoforms called α1a and α1b. Enzyme activity is increasing during the smoltification process and is a strong indicator for that the process is taking place. The aim of this study was to investigate a landlocked strain of Atlantic salmon and see how the enzyme activity is developing in comparison with the gene expression of the mRNA that is coded for the enzyme. The study was carried out between March and May in the hatchery in Brattfors, Värmland. Fish were sampled at four occasions. The enzyme activity was compared between two groups of salmon where one group had full ration of food, 100% and the other group had a 15% food ration. The enzyme activity for the 100% group was then compared with the gene expression from the same group. The hypothesis was that food availability should effect smoltification and that the 15% group would have a faster increase in activity compared with the 100% group. There should also be some correlation between enzyme activity and gene expression. Na+/K+-ATPase enzyme activity showed no major differences between the groups except for a significant difference at the last sampling. Both groups had a large increase in activity from the second to the third sampling with a peak on 3.16 µmol ADP/mg/h at most. This was followed by a drop in activity at the last sampling date. The gene expression showed a fast increase of the α1b gene over the study with drop in the last sampling and the α1a gene had a constant increase from the first to the last sampling. The comparison with enzyme activity and gene expression showed a weak correlation. Compared with studies done on anadromous salmon and the land locked salmon in this study had a different development in gene expression. This could be explained that the different life strategies play an important role how the genes are expressed.</p> / <p>Under smoltifieringen utvecklar atlantlaxen (Salmo salar) olika anpassningar för att överleva i havsmiljö. En av de vikigaste anpassningarna är att utsöndra överskott av salt via gällarna. Exkretionen är kontrollerad av ett enzym som heter Na+/K+-ATPas som produceras i en α-subenhet av två isoformer av gener som heter α1a och α1b. Enzym aktiviteten ökar under smoltifieringen och är en stark indikator på att processen sker. Målet med denna studie var att undersöka en sjövandrande stam av atlantlax och se hur enzymaktiviteten utvecklas i jämförelse med gen expressionen av mRNA som kodar för produktionen av enzymet. Studien genomfördes vid fiskodlingen i Brattfors, Värmland där prover togs vid fyra tillfällen. Enzymaktiviteten jämfördes mellan två grupper av lax där en grupp fick full matranson 100 % och en grupp fick 15 % matranson. Senare jämfördes enzymaktiviteten för 100 % gruppen med gen expressionen inom samma grupp. Hypotesen var att tillgängligheten på mat skulle påverka smoltifieringen och att 15 % gruppen skulle ha en snabbare ökning i jämförelse med 100 % gruppen. Det skulle också vara en viss korrelation mellan enzymaktivitet och gen expression. Na+/K+-ATPas enzym aktiviteten visade inga större skillnader mellan grupperna förutom vid sista provtagningen. Båda grupperna hade en stor ökning från den andra till den tredje provtagningen med den högsta aktiviteten på 3.16 µmol ADP/mg/h. Detta följdes av ett fall i aktivitet vid sista provtagningen. Gen expressionen visade en snabb ökning av α1b genen över studien med en nedgång vid sista provtagningen och α1a hade en konstant men mindre ökning från första till sista provtagningen. Jämförelsen mellan enzymaktivitet och gen expression visade på en svag korrelation. Det fanns en skillnad i gen expression mellan studier gjorda på anadrom lax och sjövandrande lax i denna studie. Detta kan förklaras av att de olika livsstrategierna spelar en betydande roll i hur generna uttrycks.</p>
56

A Mechanistic Investigation of Anesthesia-Induced Spatial Learning Deficits in Aged Rats

Mawhinney, Lana J 29 April 2011 (has links)
Anesthesia-induced spatial learning impairments in aged rats model postoperative cognitive dysfunction (POCD) in the elderly surgical population. Mechanisms underlying both normal age-related cognitive decline and anesthesia-induced spatial learning deficits in aged rats were investigated. With respect to the involvement of inflammasome activation and age-related cognitive decline, I hypothesized that the aged hippocampus exhibits an elevated activation of inflammasome components contributing to elevated levels of IL-1β in the aged brain. Age-related cognitive decline was identified in a subpopulation of male Fischer 344 rats. Activation of the NLRP1 inflammasome was elevated in the aged brain, contributing to spatial learning deficits in aged rats. With respect to anesthesia-induced spatial learning impairment in aged rats, I hypothesized that an increase in NR2B subunit in the hippocampus and cortex during and following isoflurane anesthesia exposure resulting in spatial learning impairment in aged rats via disruption of downstream signaling molecule, extracellular-signal regulated protein kinase (ERK). Anesthesia exposure resulted in chronic spatial learning impairment in aged rats that were previously unimpaired in spatial learning tasks. Additionally, anesthesia induced elevated levels of N-methyl-D-aspartate (NMDA) receptor NR2B subunit protein expression in aged. It was concluded that various factors contribute to age-related spatial impairment including: NLRP1 inflammasome activation and NMDA receptor NR2B protein expression elevation. It was also concluded that anesthesia exposure exacerbates the elevation in NR2B protein expression in the aged brain, with subsequent disruption of ERK activation leading to chronic spatial learning deficits in aged rats. In the final chapter, a relationship for the interplay between inflammation and NMDA receptor function in the aged brain is discussed. In addition, a novel mechanism for anesthesia-induced cognitive deficits is presented. Therapeutic treatments for cognitive decline and anesthesia-induced cognitive deficits are explored. Finally, future lines of research are proposed.
57

The regulation and role of hypoxia inducible factor-1 (HIF-1) in human cancer

Skinner, Heath Devin. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vi, 156 p. : ill. (some col.). Includes abstract. Includes bibliographical references.
58

Relationship between Na+/K+ -ATPase activity and α-subunit gene expression during the smoltification in Atlantic salmon (Salmo salar)

Bergqvist, Jonas January 2008 (has links)
During the smoltification the Atlantic salmon (Salmo salar) develop different adaptations to survive in oceanic environment. One of the most important adaptations is the ability to excrete the surplus of salt through the gills. The excretion is controlled by an enzyme called Na+/K+-ATPase which is produced in an α-subunit by two gene isoforms called α1a and α1b. Enzyme activity is increasing during the smoltification process and is a strong indicator for that the process is taking place. The aim of this study was to investigate a landlocked strain of Atlantic salmon and see how the enzyme activity is developing in comparison with the gene expression of the mRNA that is coded for the enzyme. The study was carried out between March and May in the hatchery in Brattfors, Värmland. Fish were sampled at four occasions. The enzyme activity was compared between two groups of salmon where one group had full ration of food, 100% and the other group had a 15% food ration. The enzyme activity for the 100% group was then compared with the gene expression from the same group. The hypothesis was that food availability should effect smoltification and that the 15% group would have a faster increase in activity compared with the 100% group. There should also be some correlation between enzyme activity and gene expression. Na+/K+-ATPase enzyme activity showed no major differences between the groups except for a significant difference at the last sampling. Both groups had a large increase in activity from the second to the third sampling with a peak on 3.16 µmol ADP/mg/h at most. This was followed by a drop in activity at the last sampling date. The gene expression showed a fast increase of the α1b gene over the study with drop in the last sampling and the α1a gene had a constant increase from the first to the last sampling. The comparison with enzyme activity and gene expression showed a weak correlation. Compared with studies done on anadromous salmon and the land locked salmon in this study had a different development in gene expression. This could be explained that the different life strategies play an important role how the genes are expressed. / Under smoltifieringen utvecklar atlantlaxen (Salmo salar) olika anpassningar för att överleva i havsmiljö. En av de vikigaste anpassningarna är att utsöndra överskott av salt via gällarna. Exkretionen är kontrollerad av ett enzym som heter Na+/K+-ATPas som produceras i en α-subenhet av två isoformer av gener som heter α1a och α1b. Enzym aktiviteten ökar under smoltifieringen och är en stark indikator på att processen sker. Målet med denna studie var att undersöka en sjövandrande stam av atlantlax och se hur enzymaktiviteten utvecklas i jämförelse med gen expressionen av mRNA som kodar för produktionen av enzymet. Studien genomfördes vid fiskodlingen i Brattfors, Värmland där prover togs vid fyra tillfällen. Enzymaktiviteten jämfördes mellan två grupper av lax där en grupp fick full matranson 100 % och en grupp fick 15 % matranson. Senare jämfördes enzymaktiviteten för 100 % gruppen med gen expressionen inom samma grupp. Hypotesen var att tillgängligheten på mat skulle påverka smoltifieringen och att 15 % gruppen skulle ha en snabbare ökning i jämförelse med 100 % gruppen. Det skulle också vara en viss korrelation mellan enzymaktivitet och gen expression. Na+/K+-ATPas enzym aktiviteten visade inga större skillnader mellan grupperna förutom vid sista provtagningen. Båda grupperna hade en stor ökning från den andra till den tredje provtagningen med den högsta aktiviteten på 3.16 µmol ADP/mg/h. Detta följdes av ett fall i aktivitet vid sista provtagningen. Gen expressionen visade en snabb ökning av α1b genen över studien med en nedgång vid sista provtagningen och α1a hade en konstant men mindre ökning från första till sista provtagningen. Jämförelsen mellan enzymaktivitet och gen expression visade på en svag korrelation. Det fanns en skillnad i gen expression mellan studier gjorda på anadrom lax och sjövandrande lax i denna studie. Detta kan förklaras av att de olika livsstrategierna spelar en betydande roll i hur generna uttrycks.
59

Regulation of hepatic ALS and IGFBP-1 expression

Hepp, Michael Emerson 21 June 2005
The insulin-like growth factor (IGF) system is composed of IGF, IGF binding proteins (IGFBP-1 to -10) and the acid labile subunit (ALS). IGF exists as two isoforms, IGF-I and IGF-II. IGF-I is the major circulatory form and is primarily secreted by the liver. It functions to regulate proliferation and differentiation in a number of different cell types and elicits an insulin-like metabolic effect. As well as being regulated at levels of transcription and translation, IGF-I activities are also regulated through formation of complexes in circulation. IGF complexes form as binary complexes, such as the IGFBP-1 complex, and ternary complexes containing IGF-I, IGFBP-3 and ALS. Binary and ternary IGF complexes function to maintain stable pools of bioactive IGF-I. They also function to increase IGF half-life and sequester IGF in the bloodstream. <p> ALS and IGFBP-1 are well characterized and exist as 85 kDa and 32 kDa proteins, respectively. They are expressed primarily in liver hepatocytes. Circulating ALS binds the IGF-I-IGFBP-3 complex and increases IGF half-life from 10 min in the IGFBP-3 binary complex to 10-15 hr in the ternary complex. IGFBP-1 binds IGF-I and increases the half-life from 10 min to 30 min. The ternary complex is the predominant IGF-I binding protein complex found in circulation. The IGFBP-1 complex represents only a small fraction of circulating IGF complexes. <p> In this thesis ALS and IGFBP-1 regulation were investigated in terms of expression related to metabolic modulators and streptozotocin (STZ)-induced diabetes. Results from rat studies showed a decreased liver ALS gene expression in STZ-induced diabetic rats. STZ-treatment in rats mimics type-I diabetes with no change in secreted insulin with increase of circulatory glucose. The administration of insulin into the STZ-induced diabetic rats brought ALS levels to that of the untreated controls. ALS expression was positively regulated by insulin in H4IIE hepatoma cells. Growth hormone (GH), glucose, dexamethasone also positively regulated ALS gene expression while cAMP (2-b-cAMP) acted as a negative regulator in H4IIE cells. HepG2 cells expressing constitutively active protein kinase B (PKB) (HepG2-PKB-CA) increased ALS gene expression to levels 20% higher then parental HepG2. Insulin treatment of these cells unexpectedly increased ALS levels in both parental and PKB-CA HepG2. This may have indicated a partial regulatory role of the mitogen activated protein (MAP) kinase pathway as PKB was thought to be over-expressed therefore rendering the insulin signal redundant. Inhibition of the phosphoinositol-3 (PI-3) kinase and MAP kinase pathways through wortmannin and PD98059 incubation, respectively, suggested a possible interplay or crosstalk between the two pathways in insulin signaling. PKB is known to be activated through the PI-3 kinase pathway. Results suggested possibility that PKB may interact through the MAP kinase pathway in regulation of ALS gene expression. The activity of cAMP on ALS gene expression may occur through interaction with the PI-3 kinase pathway as inhibition enhanced the negative effect of cAMP on ALS expression. <p> The secretion of IGFBP-1 was positively regulated by glucose and GH and negatively regulated by insulin in H4IIE cells. HepG2-PKB-CA cells showed significantly lower IGFBP-1 secretion as compared to parental HepG2 cells. The involvement of the PI-3 and MAP kinase pathways in the modulator-mediated effect on IGFBP-1 secretion were. As observed for ALS expression, the effect of insulin on IGFBP-1 secretion may also be affected through interplay or crosstalk between the PI-3 kinase and MAP kinase pathways. Glucose and GH effected IGFBP-1 expression and secretion independent of these pathways although glucose expression may interact in some way through the PI-3 kinase pathway. Our investigation of hepatic regulation of IGFBP-1 secretion and ALS gene expression has shown regulatory roles for the metabolic hormones tested, especially insulin. Mechanisms of cell signaling have also been approached with the use of pathway inhibiters and HepG2-PKB-CA cells. Much work is yet to be done to fully understand the effects of insulin and other hormones on the secretion and expression of IGFBP-1 and ALS.
60

The C-Phycocyanin/Beta Protein Inhibits Cancer Cell Proliferation

Wang, Haizhen 22 April 2008 (has links)
C-Phycocyanin (C-PC) from blue-green algae has been reported to have various pharmacological characteristics, including anti-inflammatory and anti-cancer activities. In this study, the beta-subunit of C-PC (ref to as C-PC/beta) was expressed and purified from bacteria E. coli BL-21. The recombinant C-PC/beta has been demonstrated to have anticancer properties. Under the treatment of 5 microM of the recombinant C-PC/beta, four different cancer cell lines accrued a high proliferation inhibition and apoptotic induction. The C-PC/beta interacts with membrane-associated beta-tubulin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been found. Under the treatment of the C-PC/beta, depolymerization of microtubulin and actin-filament was observed. The cells underwent apoptosis with increase of Caspase-3 and Caspase-8 activities. Cell cycle was arrested at G0/G1 phase under the treatment of C-PC/beta. In addition, the nuclear level of GAPDH decreased significantly. Inhibition of cancer cell proliferation and induction of apoptosis may potentate C-PC/beta as a promising cancer prevention or therapy agent.

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